Roughness Control and Surface Texturing in Lubrication 8H35 9H15 Keynote Speaker D

Web site www.metprops2019.org

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Local Organising Committee CHAIR: Prof. Hassan Zahouani (University of Lyon, France - Halmstad University, Sweden) Prof. Cyril-Pailler Mattéi (University of Lyon, France) Prof. Haris procopiou (Université Paris I, Panthéon-Sorbonne, France) Prof Philippe Kapsa (CNRS, France) Dr. Roberto Vargiolu (Univesity of Lyon, France) Dr. Coralie Thieulin (University of Lyon, France)

International Program Committee Prof. Liam Blunt (University of Huddersfield, UK) Prof. Christopher Brown (WPI Worcester Polytech Institute, USA) Prof. Thomas Kaiser (University of Hamburg, Germany) Prof. Mohamed El Mansori (Ecole Nationale Supérieure d'Arts et Métiers (ENSAM), France) Prof. Richard Leach (University of Nottingham, UK) Prof. Bengt-Göran, BG, Rosén (Halmstad University, Sweden) Dr. Ellen Schulz-Kornas, (Max Planck Weizmann Center for Integrative Archaeology and Anthropology, Germany) Prof. Tom R Thomas (Halmstad University, Sweden) Prof. Michael Wieczorowski (University of Poznan, Poland) Prof. Hassan Zahouani (University of Lyon - ENISE - Ecole Centrale de Lyon, France)

International Scientific Committee A. Archenti, Royal Institute of Technology, Sweden K. Adachi, Tohoku University, Japan F. Blateyron, Digital Surf, France L. Blunt, University of Huddersfield, UK D. Butler, Nanyang Tech. Uni. NTU, Singapore C. Boulocher , Veagro-sup , France C. Brown, Worcester Polytechic Institute, USA M. El-Mansori, Ecole Nationale Superieure d'Arts et Metiers , France C. Evans, University of North Carolina - Charlotte, USA C. Giusca, National Physical Laboratory, UK S. Gröger, Chemnitz University of Technology, Germany W. Hongjun, Beijing Information Science & Technology University, China T. Kaiser University of Hamburg, Germany M. Kalin, University of Lubljana, Slovenia P. Kapsa, CNRS, France P. Krajnik, Chalmers University of Technology, Sweden R. Leach, University of Nottingham, UK Haris Procopiou (Université Paris I, Panthéon-Sorbonne, France) T.-Y. (Victor) Lin, Center for Measurement Standards, ITRI, Taiwan M. Malburg, Digital Metrology, USA P. Pawlus, Rzeszow University of Technology, Poland B.-G. Rosén, Halmstad University, Sweden E. Schulz-Kornas, Max Planck Weizmann Center for Integrative Archaeology and Anthropology, Germany P. Scott, University of Huddersfield, UK J. Seewig, University of Kaiserslauten, Germany T.R. Thomas, Halmstad University, Sweden 3

T. Vorburger, National Institute of Standards and Technology, USA M. Wieczorowski, University of Poznan, Poland X. Q. (Jane) Jiang, University of Huddersfield, UK H. Zahouani, University of Lyon, France – Halmsatd University, Sweeden 4

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7H00 Welcoming of participants 8H15 Introduction Session 1 Chairman Ph. Kapsa

Roughness control and Surface texturing in lubrication 8H35 9H15 Keynote speaker D. Mazuyer, Professor Ecole Centrale de Lyon (France)

Surface topography fine structure and sub-surface defects in laser powder bed fusion metal additive parts 9H15 9H35 Conference 023 Zachary C. Reese, Chris Evans, Jason Fox, Felix Kim, John Taylor Model-based design of areal material measures based on component surfaces 9H35 9H55 Conference 026 M Eifler, K Klauer, J Seewig, B Kirsch, JC Aurich Effect of Material Extrusion Temperature and Speed on the Properties of 3D Printed PEEK Parts 9H55 10H15 Conference 003 S.A. Brady, S. Lesko and D. P. Dowling Evaluation of methods for analysis of metal AM surface texture 10H15 10H35 Conference 031 J Berglund,, J Holmberg,, O Flys,, A Wretland, B-G Rosén 10H35 11H00 Coffee break Visit Stands and Posters Session 2 Chairman BG. Rosén Surface topography characterization of barriers produced by additive manufacturing for guided bone regeneration 11H00 11H20 Conference 033 B-G Rosen, Vijeth Reddy,, Amogh Vedantha Krishna, Peter Abrahamsson Influence of surface topography on diffusion bonding of stainless steel parts 11H20 11H40 Conference 034 Chris Evans, Brigid Mullany, Brian K. Paul, Venkata Rajesh Saranam, Ali Tabei, Subhasree Srenevas Features selection approaches for an objective control of cosmetic quality of coated surfaces 11H40 12H00 Conference 039 S. Bessonnet ,, M. El Mansori,, S. Mezghani, R. Pee, S. Pinault A characterization framework for freeform surfaces 12H00 12H20 Conference 071 L. Pagani, W. Zeng, S. Lou, F. Blateyron, X. Jiang and P. J. Scott. 12H30 13H45 Lunch Visit Stands and Posters Session 3 Chairman M. El Mansori

Detonation spraying : technology, equipment and applications V. Ulianitsky, I. Smurov, A. Sova 13H45 14H25 Keynote speaker I. Smurov, Professor Ecole Nationale de Saint-Etienne (France)

Surface characterisation with light scattering and machine learning 14H25 14H45 Conference 010 M. Doubenskaia, I. Smurov,, A. Sova, P. Petrovskiy Multiscale characterization of mass finished rings 14H45 15H05 Conference 049 T Bartkowiak, B Gapiski, K Grochalski, M Wieczorowski Polishability of coatings – a case study 15H05 15H25 Conference 053 B-G Rosen, S Rebeggiani, Simon Palm Surface characterisation with light scattering and machine learning 15H25 15H50 Conference 011 Mingyu Liu, Nicola Senin, , Richard Leach 15H50 16H15 Coffee break Visit Stands and Posters Session 4 Chairman L. Blunt

Multi-scale-analysis & Characterisation of surface topography 16H15 16H55 Keynote speaker C. Brown, Professor Worcester Polytechnic Institute (USA)

Multiscale analyzes of pavement texture during polishing 16H55 17H15 Conference 013 W Edjeou, , V Cerezo, H Zahouani, F Salvatore An exploration of motifs parameters using watershed segmentation and morphological envelopes 17H15 17H35 Conference 064 F Blateyron, B Leroy Development of a novel method to characterize mean surface peak curvature of dental implant surfaces 17H35 17H55 Conference 016 A Zabala, L Blunt, A Aginagalde, I Llavori, Naiara Rodriguez-Florez, W Tato A topographical analysis based on three transformations 17H55 18H15 Conference 019 R Vayron, C David, R Deltombe, F Robache, G Le Goic, M Bigerelle Strong functional correlation with wetting using multiscale topographic analyses and characterizations 18H15 18H35 Conference 072 R J Daniello, A J Frewin, C A Brown 18H35 End Program July 4 , 2019

8H15 Introduction Session 5 Chairman V. Fridrici

Measuring archaeological surfaces to throw light 8H35 9H15 Keynote speaker on the present and prepare for the future H. Procopiou, Professor Université Paris Panthéon Sorbonne (France)

Areal surface topography representation of as-built and post 9H15 9H35 Conference 029 Olena Flys,, Amogh Vedantha Krishna,, Vijeth V Reddy, Johan Berglund Investigations on modeling and visualization of surfaces 9H35 9H55 Conference 032 Olena Flys,, Vijeth Reddy,, Amogh Vedantha Krishna, B-G Rosen Surface defect detection and quantification using statistical based metrics 9H55 10H15 Conference 035 F Azimi, B Mullany The influence of edge effect on the wavelet analysis process 10H15 10H35 Conference 069 Gogolewski D, Makieła W. 10H35 11H00 Coffee break Visit Stands and Posters Session 6 Chairman R. Leach Comparison of three multiscale approaches for topography analysis 11H00 11H20 Conference 006 R Guibert, S Hanafi, M Bigerelle, C A Brown Crossing-The-Line Segmentation as a Basis for Roughness Parameter Evaluation 11H20 11H40 Conference 060 J Seewig, PJ Scott, M Eifler, D Hüser Changement A model of light transmission on abraded glasses 11H40 12H00 Conference 036 M Bigerelle, F Robache, PE Mazeran Material & Surface design methodology – the user study framework 12H00 12H20 Conference 052 M Bergman, B-G Rosen, L Eriksson, L Lundeholm 12H30 13H45 Lunch Visit Stands and Posters Session 7 Chairman P. Pawlus

Surfaces - Topography and Topology 9H35 9H15 Keynote speaker G.W. Wolf, Professor University of Klagenfurt (Austria)

Improving Accuracy of Fitting of Freeform Surfaces 14H25 14H45 Conference 008 M Poniatowska, D Groch Vertical Focus Probing and smooth surface measurement by an optical surface measuring instrument based on Focus-Variation 14H45 15H05 Conference 070 K Zangl, R Danzl, F Helmli, M Prantl Multiscale analysis of the morphological signature of roping 15H05 15H25 Conference 037 J. Marteau, J.-D. Mithieux, R. Deltombe, M. Bigerelle Performance of Pin and Roller Surfaces of Truck's Valvetrain under Contaminated Lubricating Conditions 15H25 15H50 Conference 050 S. John, P.-J. Lööf, Z. Dimkovski, Jonas Lundmark, J. Mohlin, Lars Hammerström 15H50 16H15 Coffee break Visit Stands and Posters Session 8 Chairman M. Bigerelle Influence of different post-processing methods on surface 16H15 16H35 Conference 051 Amogh Vedantha Krishna, Vijeth V Reddy, Olena Flys, Gunnar Nilsson Feature-based characterisation of Ti6Al4V electron beam powder bed fusion surfaces fabricated at different orientations 16H35 16H55 Conference 065 Lewis Newton, Nicola Senin, Bethan Smith and Richard Leach Mathematical reference standards for validating software for calculating surface texture parameters 16H55 17H15 Conference 066 Luke Todhunter, Richard Leach, Simon Lawes, François Blateyron and Peter Harris Optical metrology and multi-scale characterization of surfaces 17H15 17H35 Conference 067 Simon Desage The Use of Areal Surface Texture Parameters in Characterization of Worn Surfaces 17H35 17H55 Conference 068 P Pawlus, A Dzierwa 17H55 End

Gala diner 19H30 Boarding, Marriott Hotel 20H00 Boat Hermes II Departure of navigation, visit of Lyon 22H30 Arrival, Marriott Hotel 23H30 End of the gala dinner Last minute registration for the gala dinner: contact the organizing committee (Price 90 €) Program July 5 , 2019

8H15 8H35 Introduction Session 9 Chairman C. Brown

Wettability and surface texture 8H35 9H15 Keynote speaker E. Contraires, Assistant Professor Ecole Centrale de Lyon (France)

Coherent Wave Scattering Technology for Decision Making on 9H15 9H35 Conference 055 S Rebeggiani, L Bååth,, B-G Rosen, Z Dimkovski Case studies in X-ray computed tomography surface texture 9H35 9H55 Conference 056 Adam Thompson, Nicola Senin, Richard Leach The Development of Long-Wavelength X-Ray Reflectivity for Thin Films Thickness Measurement in Semiconductor Industry 9H55 10H15 Conference 057 Bo-Ching He, Guo-Dung Chen, Chun-Ting Liu, Wei-En Fu and Wen- Li Wu Integral analysis of selective laser melting of intermetallic NiTi and TiAl powder 10H15 10H35 Conference 009 M. Doubenskaia, I. Smurov, A. Sova, P. Petrovskiy Session 10 Chairman C. Thieulin 10H35 11H00 Coffee break Visit Stands and Posters Controlling the visual appearance and texture of injection 11H00 11H20 Conference 058 A. Sjögren, B-G Rosen, Vijeth Reddy, Amogh V Optical properties of micro-textured injected polymer parts 11H20 11H40 Conference 063 R. Labayrade, A-C Brulez, S. Valette, E. Contraires, S. Benayoun A coupled method for characterizing the elasticity, firmness 11H40 12H00 Conference 047 M. Ayadh,, M-A. Abellan, C. Didier, A. Bigouret, H. Zahouani Skin folding phenomenon investigation: insights on skin 12H00 12H20 Conference 005 A Guillermin, M Ayadh, E Feulvarch, H Zahouani Multiscale characterization of surface anisotropy 12H20 12H40 Conference 075 T Bartkowiak, J Berglund, C A Brown 12H40 End Conclusion 11 Keynote speaker www.metprops2019.org conference

Roughness control and Surface texturing in lubrication Denis Mazuyer

Denis Mazuyer Laboratoire de Tribologie et Dynamique des Systèmes Ecole Centrale de Lyon France

Abstract:

One of the most important challenges for tribologists in the permanent race to the reduction of energy consumption is to avoid friction dissipation. Lubrication is one of the means to achieve this goal. When a bulk layer of lubricating fluid separates two rubbing surfaces, the lubricant facilitates the relative motion of the solids. Then, the shearing of the lubricant accommodates the sliding velocity and the frictional dissipation is mainly dependent on viscosity. Thus, tribologists need to quantify the basic properties of the lubricant and the surfaces it is separating. Previously, the bulk properties of these materials (lubricant and solids) were sufficient. In most of lubrication process (metalworking, engines, gears, bearings,...), this is no longer true and the accurate knowledge of surface and lubricant properties is required on a scale which is small or comparable with the film thickness. Nowadays, this means a scale in the range 10-9 – 10-7 m at which the surface phenomena and the interface confinement cannot be neglected anymore. In this framework, most of the research strategies converge towards surface functionalization in order to control both its roughness and its physico-chemistry, according to its interaction with the lubricant. One way to investigate these phenomena and their effects on the friction dissipation is to predict or to measure the evolution coefficient of lubricated contact vs the viscous friction coefficient, referred to as the well-known ‘Stribeck curve’. The latter is often used in tribology to describe the lubrication regimes. In this work, we show how such curves provide a better understanding of interfacial friction in thin film lubrication process that involves strong surfaces effects. This approach has been developed to investigate the role surface topography and texturing on the frictional response of two types of contacts: a wet soft contact between a smooth glass and a rough rubber and high-pressure lubricated contact with random or patterned roughness. Short bio

Denis Mazuyer graduated in Engineering in 1986 and holds a PhD in Mechanical Engineering (1989) from École Centrale de Lyon. He obtained his ‘agrégation’ in Mathematics (highest national teaching examination) in 1991 and his habilitation to supervise research in 1995. He was recruited as a researcher by the French National Centre for Scientific Research (CNRS) in 1989. He was promoted as a Full Professor at École Centrale de Lyon in 2000. His research in the "Laboratoire de Tribologie et Dynamique des Systèmes" (LTDS) mainly concerns lubricated interfaces. He heads LTDS from 2007 to 2015. He was awarded the Edmond Bisson Prize from the Society of Tribologists and Lubrication Engineers (STLE) in 2009. He was the President of École Centrale de Lyon’s select board of directors from 2013 to 2017. He was one of the founder of Manutech – USD, a lab which develops femtosecond LASER facilities for surface texturing and hybrid additive manufacturing. He was the president of Manutech – USD's board of directors, from 2012 to 2018. 13 Keynote speaker www.metprops2019.org conference

DETONATION SPRAYING: TECHNOLOGY, EQUIPMENT AND APPLICATIONS Igor Smurov

Igor Smurov Ecole Nationale d’Ingénieurs de St Etienne France

V. Ulianitsky1, I. Smurov2,3, A. Sova2, P. Petrovskiy3

1Lavrentyev Institute of Hydrodynamics of the Siberian Branch of Russian Academy of Sciences, 15 Lavrentyev avenue, Novosibirsk, 630090, Russia

2Université de Lyon, Ecole Nationale d'Ingénieurs de Saint-Etienne (ENISE), LTDS Laboratory, 58 rue Jean Parot, 42023 Saint-Etienne Cedex 2, France

3National University of Science & Technology (MISIS), 4 Leninsky pr., 119049, Moscow, Russia

E-mail: [email protected]

Keywords: detonation spraying, protective coatings, tribo performance, optical diagnostic

Abstract Gaseous detonation is well-known as the phenomenon of highest concentration of gas-fuel combustion energy. It occurs in a gun barrel and produces detonation products flow with the temperature up to 4500K and velocity about 1200 m/sec. This advantage has been used for powder material spraying in the middle of the XX century already [1]. Iinstallation of the new generation (CCDS2000) for detonation spraying was developed [2] in Lavrentyev Institute of Hydrodynamics SB RAS as a result of long-term intensive research. Spraying was successfully realized for different powders: metals (aluminum, copper, iron, nickel, cobalt, molybdenum, etc.); alloys (steel, cast iron, nickel-chrome, brass, duralumin, self-fluxing alloys, etc.); ceramics (alumina, chromia, zirconia, titania); cermets (carbides of tungsten, chromium, titanium with a binder). Detonation coatings can be deposited on substrates made from metals, ceramics, plastics, even wood. For the majority of materials the coating thickness is in the range from 50 µm to several millimetres. Detonation coatings are applied in: aerospace, machine-building and ship- building industries, equipment for oil mining and chemical processes, machines for wood processing and paper production, equipment for metal mills and food industries, components of electrical and electronic devices [3]. 14 Keynote speaker www.metprops2019.org conference

The CCDS installation equipped by a precise-dosage twin powder feeding system was used for deposition of composite coatings: metal / metal, metal /ceramic, ceramic /ceramic, cermet / ceramic and cermet with metal interlayers including graded and multilayered coatings. Computer control provides a flexible adjustment of the detonation gases impact on powder thus allowing selecting optimal for each material spraying parameters to form high-quality innovative coatings. Properties of detonation coatings from composite powders based on carbides are studied: the main focus is on tungsten carbide. Powders with carbide inclusions of different size ranging from tens of microns down to the submicron level are deposited. Composites with cobalt binder content from 12 to 30 wt. % and composite binders with chromium and nickel additions are studied. A comparative analysis of tribo performance between composites with chrome carbide and the complex titan-chrome carbide is done. Physical properties and functional performance of the obtained coatings are studied: Microstructure and microhardness analyses, adhesion/cohesion, abrasion, erosion and friction wear tests of the coatings are performed. It is found that the studied materials do not exhibit overwhelming advantages in performance compared with one another. For example, though composites with a relatively high content of binder have relatively low wear resistance, they exhibits the highest adhesion to the substrate, while composites with titan- chrome carbide compared to tungsten carbide-based composites have higher dry friction and lower lubricated friction coefficients.

References [1] R.M. Poorman, H.B. Sargent, and H. Lamprey. US Patent 2,714,553. August 2, 1955. [2] V. Ulianitsky, A. Kirjakin, A. Shtertser, and S. Zlobin, Detonation Spraying Unit, RF Patent 2399 431, 20.09.2010. [3] V. Ulianitsky, A. Shtertser, S. Zlobin, and I. Smurov, Computer-Controlled Detonation Spraying: From Process Fundamentals Toward Advanced Applications, J. of Therm. Spray Technology, 2011, 20 (4), p. 791-801. [4] V. Ulianitsky, I. Smurov, Computer controlled detonation spraying as a universal method to deposit coatings of diverse nature, 7-th RIPT Limoges, 9 - 11 December 2015, Limoges, France. [5] A. Sova, D. Pervushin, I. Smurov. Development of multimaterial coatings by cold spray and gas detonation spraying // Surface & Coatings Technology, vol. 205, 2010, pp. 1108–1114.

15 Keynote speaker www.metprops2019.org conference

Multiscale Analyses & Characterizations of Topographies C.A. Brown

C.A. Brown, Professor of Mechanical Engineering Worcester Polytechnic Institute Worcester, Massachusetts USA

Multiscale analyses and characterizations of surface topographies are examined critically from the perspective of research value. Research value in Surface Metrology stems largely from the discovery of strong functional correlations with processing and performance, particularly the latter, and the establishment of confident discriminations, by topographic analyses and characterizations. Commonalities in research of this type suggests that there are four principles, 1) characterizing geometric features appropriate for the application, 2) using appropriate scales, 3) using appropriate statistics, and 4) using measurements with enough fidelity at appropriate scales. Semantic and theoretical frameworks and systems for organizing and designating multiscale analyses are discussed.

Biography

Brown earned his PhD at the University of Vermont in 1983. He then spent four years in the Materials Department at the Swiss Federal Institute of Technology conducting research on metal surfaces and teaching laboratory exercises. For two years he was a senior research engineer working on surfaces and on product and process development at Atlas Copco's European research center. Since the fall of 1989 Chris has been on the faculty at WPI.

Chris has published over a hundred articles on machining, axiomatic design, sports engineering, and surface metrology applied to engineering, archeology and physical anthropology. He has patents on a fractal method for characterizing surface roughness, an apparatus for friction testing, and on sports equipment. He also developed software for surface texture analysis.

He teaches grad courses on axiomatic design, and on surface metrology, and undergraduate courses on manufacturing and on the technology of alpine skiing. He also consults and teaches courses for industry, on axiomatic design and on surface metrology. He has been a visiting professor on several occasions in France and Italy, teaching and doing research on surface metrology and axiomatic design.

Chris co-chaired the first two International Conferences on Surface Metrology (2009 and 2010) and the first two Seminars on Surface Metrology for the Americas (2011 and 2012) all at WPI, where the goal was to bring together people from all disciplines working on surface metrology.

He is a past chair of ASME B46, Committee for Classification and Designation of Surfaces; and he is Director of WPI's Surface Metrology Laboratory.

Keynote speaker www.metprops2019.org conference

Measuring archaeological surfaces to throw light on the present and prepare for the future Haris Procopiou

Haris Procopiou Université Paris I Panthéon Sorbonne France

Measurements and characterization of archaeological surfaces allow to reconstruct ancient technologies employed for their manufacture. While our society seeks “the immediacy of the innovation”, the archaeological evidence show, as do psychology and sociology, that only the “cultural and communitarian judgement” can in the long term, transform invention into innovation. At a time when innovation is seen as a driver of sustainable development, what can we learn from the past? The archaeological record provides multiple solutions that could be of some utility in the future, be it regarding the recycling of objects or of waste, the modifications of functions, the packaging and the like. The different case studies that will be present aim to show that one of the factors of progress for our period, rather than a headlong rush, is the reuse of ancient skills or relationships with the world in combination with modern techniques.

17 Keynote speaker www.metprops2019.org conference

Surfaces - Topography and Topology Gert W. Wolf

Gert W. Wolf University of Klagenfurt Austria

In the standard ISO 25178-2 two kind of parameters, viz., field parameters and feature parameters are defined for surface texture characterisation. The main difference between them is the fact that for the first group all points of a scale-limited surface are considered, whereas for the second group only a subset of predefined topological surface features is taken into account. As a consequence, two prerequisites are indispensable for the determination of the feature parameters, namely, an adequate data structure for surface characterisation and a suitable formal method for surface generalisation, i.e. for the successive elimination of the less important surface features. These problems, however, are not only specific for surface topography, but they have a long history also in geography and cartography.

With respect to the formal characterisation of surface topography, two basic approaches can be distinguished, viz., the characterisation (a) by arbitrary data points and (b) by the critical points (surfacespecific points), i.e. the pits, passes and peaks of the surface. Although of limited performance, the first approach is still widely employed, primarily due to historical reasons. Despite the fact that the second approach is well established in such sciences as computational geometry or computer graphics, it may nevertheless be regarded as an exception rather than as the rule.

Three data structures, all of which rely on the critical points of a surface, will be presented, namely, (a) Morse-Smale complexes, (b) weighted surface networks and (c) contour trees (change trees). Although these data structures, which were developed independently from each other, seem to have no similarities, it will be shown that all of them rest on a common theoretical framework.

A second point of interest is how the relevance of the surface-specific points and surface-specific lines can be measured. Although all existing concepts are based on relative differences in altitudes between critical points, the approaches vary slightly in dependence of the chosen data structure. The two major concepts employed are (a) persistence, which is defined as the lifetime between birth and death of a topological feature, whereby features having a long lifetime are considered to be important, while features having a short lifetime are considered to be unimportant and (b) the importance of the surface-specific points, which is defined via the edge-weights of the corresponding surface network. Similar to persistence, critical points with high importance-values are regarded as important ones with respect to the macro-structure of the surface, whereas critical points with low importance-values are regarded as unimportant ones.

Surface simplification, finally, describes the process of deriving from an original surface a second surface of decreased complexity, but with all relevant characteristics with respect to a predefined objective being retained. Within the geosciences the concept is associated with map generalisation, 18 Keynote speaker www.metprops2019.org conference

the transition from large-scale to small-scale maps, while in the technical sciences the concept is related to the reduction or elimination of measurement noise.

Depending on which data structure has been chosen for the representation of a given surface, different simplification methods are available. For the previously described data structures based on the critical points, a theorem proven by Matsumoto may be regarded as the core theorem with respect to surface simplification. Applied to two-dimensional surfaces, it says, in simple terms, that from a topological point of view the only valid approach for their simplification is the pairwise elimination of a pit together with its lowest adjacent pass or of a peak together with it highest adjacent pass. The importance of Matsumoto's Theorem results from its generality, with the propositions being independent of a chosen data structure for surface representation. Topologically speaking, it can be considered as a generalisation of theorems that were proved for specific contractions being defined for particular data structures. The combination of the two concepts relevance of a topological feature and degree of simplicity with the assertion of Matsumoto's Theorem enables us to specify a formal procedure for the simplification of a surface.

In conclusion, it will be shown how the results obtained are incorporated into the standard ISO 25178- 2. 19 Keynote speaker www.metprops2019.org conference

Dynamic wetting of droplets on textured polymer surfaces Elise Contraires

Elise Contraires Ecole Centrale de Lyon France

Elise Contraires, Matthieu Guibert, Stéphane Valette, Alain Le Bot, Stéphane Benayoun

Laboratoire de Tribologie et Dynamique des Systèmes, UM5513 Ecole Centrale de Lyon, 36 avenue Guy de Collongue, F-69134 Ecully

Surface topography is well known for the modification and control of surface properties such as adhesion or wetting. Numerous examples can be found in literature, often based on biomimicry among which the famous lotus leaves or lizard skins.

We have developed a process to generate controlled surface topography in polymer samples, based on laser texturing and polymer microinjection. This technology is a way to produce a large number of samples with high reproducibility and various available topography designs.

Such topographies affect wetting properties by modifying contact angle and contact angle hysteresis. As a consequence, dynamic wetting properties are also changed with the presence of grooves, pillars or ripples.

After a presentation of the texturing process, the dynamic behavior of droplets on such surfaces is detailed for two specific situations: the condensation of very small droplets in an environmental chamber and the deformation and displacement of droplets submitted to mechanical vibrations. A focus is made on the relationship between surface topography and droplet dynamics.

20 Abstract submitted to the www.metprops2019.org conference

SESSION 1

21 Abstract submitted to the www.metprops2019.org conference

Conference 023

Surface topography fine structure and sub-surface defects in laser powder bed fusion metal additive parts

Zachary C. Reese1, Chris Evans1, Jason Fox2, Felix Kim2, John Taylor1 1University of North Carolina at Charlotte, Center for Precision Metrology, 2National Institute of Standards and Technology

E-mail: [email protected]

Keywords: surface texture, additive manufacturing, subsurface damage

Abstract: Additive manufacturing (AM), particularly of metal components, is frequently touted as the “next industrial revolution”. While there are some compelling use cases, widespread adoption is currently limited, inter alia, by surface integrity issues. “As printed” surface texture and subsurface defects are critical issues. In this work, we evaluate changes in surface topography using scanning white light interferometry (SWLI) and correlate those signatures with X-ray computed topography (XCT) of subsurface defects. If successful, this work will enable surface measurements to be used to estimate or screen for bulk defects and potentially predict material performance such as fatigue and failure

Previous researchers have reported on the complexity of metal additive manufactured surfaces noting such features as the prominent weld tracks, splatter, re-entrant features, and “chevrons”. In regions where flash thermography has indicated presence of sub-surface defects, scanning electron microscopy of the surface suggest a flattening of the weld beads and changes in the chevron patterns. Under well controlled conditions, changes in laser power and speed result in changes in chevron angles, related to weld pool dimensions. We have observed regions in sample parts where the chevron pattern, symptomatic of a stable melt pool, is replaced by a chaotic “orange peel” region. In this work we have generated parts with deliberately seeded defects and analysed surface topography above those defects.

The designed defect artefact comprises ten columns of three types of defects – open hole, key-holing, and lack of fusion at a range of sizes. Two columns of these programmed defects were left uncovered (open air), allowing measurement of the original defects as well as providing a coordinate system for subsequent metrology (Figure 1). Eight further layers were added and fused in staircase fashion such that the final column is covered by 8 layers. A total of 8 samples were prepared to explore process space.

Surface topography data were obtained at each “defect” site using SWLI. Typically 5x5 stitched sites at 0.4 mm sq FoV (20% overlap) were stitched to

22 Abstract submitted to the www.metprops2019.org conference

give sufficient lateral resolution for fine structure evaluation and the lateral range to cover all characteristic features of AM surfaces over areas larger than the designed defects. Figure 2 is an example of surface topography data, in this case Fourier filtered to show stable chevron patterns around a seeded defect, but which have not been re-established after 8 layers have been fused over the defect. Preliminary XCT measurements of the defect samples guided the selection of areas on interest for microCT evaluation. 3.5 mm square (approx.) columns around target defects were removed using wire electrodischarge machining.

This paper will report the experimental methods, the surface topography analysis, and the XCT results.

Figure 1. CAD model of defect artefact (38 x 41 mm; 40 m/layer)

Figure 2. Seeded defect (left) showing stable chevrons around the defect but which do not appear in the 8th fused layer deposited over the defect.

23 Abstract submitted to the www.metprops2019.org conference

Conference 026

Model-based design of areal material measures based on component surfaces

M Eifler1, K Klauer2, J Seewig1, B Kirsch2, JC Aurich2 1Technische Universität Kaiserslautern, Institute for Measurement and Sensor- Technology 2Technische Universität Kaiserslautern, Institute for Manufacturing Technology and Production Systems

E-mail: [email protected]

Keywords: surface texture, areal calibration, measurement uncertainty, topography measurement

Abstract

The calibration of areal surface topography measuring instruments is usually performed with artificial geometries like gratings or step height artefacts [1]. Whereas for many applications this type of calibration has a sufficient precision, there are more and more applications that require small tolerances which results in the necessity of a practical calibration that is more closely related to the later performed measuring task.

When surfaces with defined surface texture parameters are designed, usually the basic principle illustrated in Figure 1a) is applied [2]. With the model-based design approach in Figure 1b) it is possible to design material measures based on component surfaces for a practical calibration. Thus, the initial point of the algorithm is a measured dataset of a surface, which is evaluated and virtually transformed in a way that on the one hand the target properties are imaged, but on the other hand also the functional properties of the surface that are relevant for the specific application are preserved. Based on the subsequent application of virtual manufacturing and measuring processes also effects from these processes can be considered in the design of the calibration sample. The algorithm performs an iteration to determine a manufacturing dataset which images desired properties for the calibration and can be manufactured and measured.

In this study, the basic approach that has been developed for the design of profile material measures e.g. with the manufacturing principle of ultra-precision turning [2-5] is extended to areal material measures and the corresponding manufacturing principle of micro-milling. Amongst others, suitable manufacturing principles for areal material measures have been identified as direct laser writing [6-8] and chipping technologies [9]. The manufacturing in this study is performed with a micro-milling process. Before manufacturing the

24 Abstract submitted to the www.metprops2019.org conference

micro-milling process is modelled in a virtual manufacturing process based on the tool geometry and the cutting path (see figure 1b). The areal virtual measurement is performed based on the transfer functions of the instruments which can be determined by an algebraic fit of a time series model [10].

With the model-based design approach, component surfaces are used to determine material measures that feature defined values of surface texture parameters Sa, Sq, Sk, Svk, Spk. Especially the function-oriented parameters are examined regarding their implementation with a material measure. The designed surfaces are manufactured with a 5-axis micro-milling process and subsequently measured with different topography measuring instruments in order to compare the actually measured texture parameters with the target parameters. Based on the results, a general methodology for a practical design of areal material measures based on component surfaces can be determined. This methodology can also help to improve the design of areal material measures and thus contribute to a better estimation of the measurement uncertainty in areal surface texture measurement.

Figure 1. Design process of material measures. a) traditional design approach, roughness parameters are defined, a sample is manufactured, sampled and evaluated, b) model-based design approach [2].

25 Abstract submitted to the www.metprops2019.org conference

Main References [1] ISO 25178-70:2014 (2014) Geometrical product specifications (GPS), Surface texture: Areal, Part 70: Material Measures. [2] Seewig J, Eifler M, Schneider F, Aurich, J.C (2016) Design and verification of geometric roughness standards by reverse engineering. Procedia CIRP 45 259-262 [3] Eifler M, Schneider F, Seewig J, Kirsch B, Aurich JC (2016) Manufacturing of new roughness standards for the linearity of the vertical axis - Feasibility study and optimization. Engineering Science and Technology, an International Journal 4 1993-2001. [4] Seewig J, Eifler M, Schneider F, Kirsch B, Aurich JC (2016) A model-based approach for the calibration and traceability of the angle resolved scattering light sensor, Surface Topography: Metrology and Properties 4 024010 [5] Eifler M (2016) Modellbasierte Entwicklung von Geometrienormalen zur geometrischen Produktspezifikation (Kaiserslautern: Germany, Ph.D. Dissertation: Technische Universität Kaiserslautern). [6] Eifler M, Hering J, von Freymann G, Seewig J (2018) Manufacturing of the ISO 25178-70 material measures with direct laser writing: a feasibility study. Surface Topography: Metrology and Properties 6 024010 [7] Hering J, Eifler M, Hofherr L, Ziegler C, Seewig J, von Freymann G (2018) Two-photon laser lithography in optical metrology, Proc. SPIE Vol. 10544-12 [8] Eifler M, Hering J, von Freymann G, Seewig J (2018) Calibration sample for arbitrary metrological characteristics of optical topography measuring instruments. Optics Express 26 16609-16623 [9] Eifler M, Klauer K, Kirsch B, Seewig J, Aurich JC (2018) Micro-milling of areal material measures - influences on the resulting surface topography. Procedia CIRP 71 122-127. [10] Keksel A, Eifler M, Seewig J (2018) Modeling of topography measuring instrument transfer functions by time series models. Measurement Science and Technology 29 095012

26 Conference 003

Effect of Material Extrusion Temperature and Speed on the Properties of 3D Printed PEEK Parts

S.A. BradyA, S. LeskoB and D. P. DowlingA

ASchool of Mechanical and Materials Engineering, University College Dublin, Dublin 4, Ireland BBruker, 7 rue de la Croix Martre, 91120 Palaiseau, France Contact: [email protected]

Polyether ether ketone (PEEK) is a thermoplastic polymer with excellent physical and chemical properties [1]–[3]. PEEK components can be fabricated using the material extrusion technique (also called fused deposition modelling (FDM)) [4]. This technique has the advantage of being able to print geometrically complex structures; however due to the filamentary method of printing there can be significant issues with the roughness of the parts [5]–[7]. Surface roughness parts produced by material extrusion can be improved by modifying the printing parameters including layer height, extrusion speed and extrusion temperature [4]. Post-processing such as vapour or mechanical smoothing can also be used to improve surface roughness. However, PEEK’s excellent chemical resistance means vapour smoothing is not a viable option and mechanical smoothing can only be carried out on external surfaces [8][9]–[11].

The aim of this work is to examine the effect printing parameters have on the surface roughness of PEEK parts produced by material extrusion. Test samples were printed at a print speed of 10 mm/s with extrusion temperatures ranging from 375 to 400 ⁰C, at 5 ⁰C increments. Once the optimum extrusion temperature was determined, the extrusion speed was varied from 10 to 22 mm/s at 3 mm/s increments. To examine the effect of extrusion temperature and speed, digital microscopy and ATR-FTIR spectroscopy measurements were carried out. Optical profilometry based on White Light Interferometry technique was further used to quantify the roughness of the printed parts. On qualitative manner, optical microscopy examination has clearly showed influence of both extrusion temperature and speed. Too high extrusion temperature causes the material to degrade with visibly burnt material while increase of extrusion speed triggers visible waviness along the tracks (Bottom part shows ). 27

Figure 1: Optical microscope images of PEEK samples printed with an extrusion temperature of 375 ⁰C (upper left) and 400 ⁰C (upper, right). Bottom part shows images with an extrusion speed of 10 mm/s (lower left) and 19 mm/s (lower right).

On chemical level, the ATR-FTIR spectroscopy exhibits an increase in material crystallisation with increasing print temperature, as the peak intensity at ~1280 cm-1 reduces and ~1305 cm-1 increases [12]–[14] (Figure 2). Evidence for some chemical degradation of the PEEK was also observed in the spectra before and after extrusion through reduction in the intensity of the peaks associated with the C- O and C-C functionality relative to that associated with the –OH group functionality (2800 and 3700 cm-1 ) [15].

Figure 2: ATR-FTIR specta of the PEEK filament as supplied, extruded at 375 ⁰C and 400 ⁰C 28

To finish, systematic roughness measurements on resulting samples will show trends where some areal roughness parameters nicely correlates with printing conditions. Those parameters, such as Mean Auto-Correlation Length or Void Volume will be described with respect to printing process and physical phenomena occurring during track formation with aim to elect key feedback parameter for PEEK 3D printed parts.

Acknowledgements - This work was supported under by SFI through the I-Form Advanced Manufacturing Research Centre – (16/RC/3872).

References

[1] D. Rymuszka, K. Terpiłowski, P. Borowski, and L. Holysz, “Time-dependent changes of surface properties of polyether ether ketone caused by air plasma treatment,” Polym. Int., vol. 65, no. 7, pp. 827–834, 2016.

[2] F. M. Cabrera, I. Garrido, J. Tejero, V. N. Gaitonde, S. R. Karnik, and J. P. Davim, “Surface Roughness Minimization in Turning PEEK-CF30 Composites with TiN Cutting Tools Using Particle Swarm Optimization,” Mater. Sci. Forum, vol. 766, pp. 109–122, 2013.

[3] M. Zalaznik, M. Kalin, and S. Novak, “Influence of the processing temperature on the tribological and mechanical properties of poly-ether-ether-ketone (PEEK) polymer,” vol. 94, pp. 92–97, 2016.

[4] O. A. Mohamed, S. H. Masood, and J. L. Bhowmik, “Optimization of fused deposition modeling process parameters: a review of current research and future prospects,” Adv. Manuf., vol. 3, no. 1, pp. 42–53, 2015.

[5] D. Pranzo, P. Larizza, D. Filippini, and G. Percoco, “Extrusion-Based 3D Printing of Microfluidic Devices for Chemical and Biomedical Applications: A Topical Review,” Micromachines, vol. 9, no. 8, 2018.

[6] M. Pérez, G. Medina-Sánchez, A. García-Collado, M. Gupta, and D. Carou, “Surface Quality Enhancement of Fused Deposition Modeling (FDM) Printed Samples Based on the Selection of Critical Printing Parameters,” Mater. (Basel, Switzerland), vol. 11, no. 8, p. 1382, Aug. 2018.

[7] L. Bochmann, C. Bayley, M. Helu, R. Transchel, K. Wegener, and D. Dornfeld, “Understanding error generation in fused deposition modeling,” Surf. Topogr. Metrol. Prop., vol. 3, no. 1, p. 14002, 2015.

[8] B. N. Turner, R. Strong, and S. A. Gold, “A review of melt extrusion additive manufacturing 29

processes: I. Process design and modeling,” Rapid Prototyp. J., vol. 20, no. 3, pp. 192–204, 2014.

[9] J. Beniak, P. Križan, Ľ. Šooš, and M. Matúš, “Roughness and compressive strength of FDM 3D printed specimens affected by acetone vapour treatment,” IOP Conf. Ser. Mater. Sci. Eng., vol. 297, no. 1, p. 12018, 2018.

[10] L. M. Galantucci, F. Lavecchia, and G. Percoco, “Quantitative analysis of a chemical treatment to reduce roughness of parts fabricated using fused deposition modeling,” CIRP Ann., vol. 59, no. 1, pp. 247–250, 2010.

[11] R. Singh, S. Singh, I. P. Singh, F. Fabbrocino, and F. Fraternali, “Investigation for surface finish improvement of FDM parts by vapor smoothing process,” Compos. Part B Eng., vol. 111, pp. 228–234, 2017.

[12] L. O. Dandy, G. Oliveux, J. Wood, M. J. Jenkins, and G. A. Leeke, “Accelerated degradation of Polyetheretherketone (PEEK) composite materials for recycling applications,” Polym. Degrad. Stab., vol. 112, pp. 52–62, 2015.

[13] L. Harris, “A Study of the crystallisation kinetics in PEEK and PEEK composites,” University of Birmingham, 2011.

[14] J. M. Chalmers, W. F. Gaskin, and M. W. Mackenzie, “Crystallinity in poly(aryl-ether-ketone) plaques studied by multiple internal reflection spectroscopy,” Polym. Bull., vol. 11, no. 5, pp. 433–435, 1984.

[15] V. Mylläri, T.-P. Ruoko, J. Vuorinen, and H. Lemmetyinen, “Characterization of thermally aged polyetheretherketone fibres – mechanical, thermal, rheological and chemical property changes,” Polym. Degrad. Stab., vol. 120, pp. 419–426, 2015.

30 Abstract submitted to the www.metprops2019.org conference

Conference 031

Evaluation of methods for analysis of metal AM surface texture

J Berglund1,2, J Holmberg1,3, O Flys1,4, A Wretland5, B-G Rosén2,4 1RISE Research Institutes of Sweden, 2Chalmers University of Technology, 3University West, 4Halmstad University, 5GKN Aerospace

E-mail: [email protected]

Keywords: Additive manufacturing, post processing, surface texture, multi-scale analysis

Abstract: Metal additive manufacturing (AM) is a manufacturing method that offers great freedom of design and the ability to produce near net shape components close to a finished state regarding geometry. Nowadays, metal AM can complement existing subtracting and moulding manufacturing methods. As with any other manufacturing method AM produced parts need to fit in bigger assemblies and need to meet functional requirements. Consequently, for many applications, post-processing needs to be employed to achieve required tolerances regarding surface texture. There are still many challenges regarding the measurement and analysis of metal AM surface texture pertaining both to obtaining high fidelity measurement data as well as how the data should be analysed. Relevant characterisation parameters for metal AM parts need to be identified and standardised that preferably are related to both functional performance and the manufacturing processes [1–3]. The areal characterisation parameters in the current standard for calculating surface roughness parameters, ISO 25178-2 [4], are formulated to accommodate characterisation of surfaces manufactured by other methods than the comparably novel method of metal AM. Most of them describe the surface in a summarising statistical way. There are also multi-scale methods available with which it can be possible to perform a more precise characterisation if used correctly [5].

In this study several methods for analysing the surface texture is compared and discussed regarding their usefulness in characterising the texture in relation to the manufacturing process and subsequent post-processing steps. The methods include multi-scale methods [5] such as Power Spectral Density [6,7] and Area- Scale analysis [8] as well as traditional filtering and calculation of ISO 25178 texture parameters [4]. The evaluated samples were manufactured by Electron Beem Melting of Ti-6Al-4V and were post-processed by an electrochemical and mechanical method in several steps, see figure 1. The surface topographies were measured with Confocal Fusion [9,10].

31 Abstract submitted to the www.metprops2019.org conference

Figure 1. 3D views of the surface topography at different steps in the post-processing process.

References [1] A. Townsend, N. Senin, L. Blunt, R.K. Leach, J.S. Taylor, Surface texture metrology for metal additive manufacturing: a review, Precis. Eng. 46 (2016) 34–47. doi:10.1016/j.precisioneng.2016.06.001. [2] F. Cabanettes, A. Joubert, G. Chardon, V. Dumas, J. Rech, C. Grosjean, Z. Dimkovski, Topography of as built surfaces generated in metal additive manufacturing: A multi scale analysis from form to roughness, Precis. Eng. (2018). doi:10.1016/j.precisioneng.2018.01.002. [3] J. Berglund, R. Söderberg, K. Wärmefjord, Industrial needs and available techniques for geometry assurance for metal AM parts with small scale features and rough surfaces, Procedia CIRP. 75 (2018) 131–136. doi:10.1016/j.procir.2018.04.075. [4] International Organization for Standardization, ISO 25178-2:2012 - Geometrical product specifications (GPS) -- Surface texture: Areal -- Part 2: Terms, definitions and surface texture parameters, (2012). [5] C.A. Brown, H.N. Hansen, X.J. Jiang, F. Blateyron, J. Berglund, N. Senin, T. Bartkowiak, B. Dixon, G. Le Goïc, Y. Quinsat, W.J. Stemp, M.K. Thompson, P.S. Ungar, E.H. Zahouani, Multiscale analyses and characterizations of surface topographies, CIRP Ann. 67 (2018) 839–862. doi:10.1016/j.cirp.2018.06.001. [6] A. Duparré, J.Ferre-Borrull, S. Gliech, G. Notni, J. Steinert and J. M. Bennett, “Surface characterization techniques for determining the root-mean-square roughness and power spectral densities of optical components”, Appl. Opt. 41 154–71, 2002. [7] T. Jacobs, T. Junge and L. Pastewka, “Quantitative characterization of surface topography using spectral analysis”, Surf. Topogr.: Metrol. Prop. 5 013001, 2017. [8] C.A. Brown, S. Siegmann, Fundamental scales of adhesion and area–scale fractal analysis, Int. J. Mach. Tools Manuf. 41 (2001) 1927–1933. doi:10.1016/S0890-6955(01)00057-8. [9] C. Bermudez, A. Matilla, A. Aguerri, Confocal fusion: towards the universal optical 3D metrology technology, in: euspen, Cranfield University Campus, Bedfordshire, UK, n.d. [10] A. Matilla, J. Mariné, J. Pérez, C. Cadevall, R. Artigas, Three-dimensional measurements with a novel technique combination of confocal and focus variation with a simultaneous scan, in: Opt. Micro- Nanometrology VI, International Society for Optics and Photonics, 2016. doi:10.1117/12.2227054.

32 Abstract submitted to the www.metprops2019.org conference Conference 033

Surface topography characterization of barriers produced by additive manufacturing for guided bone regeneration

B-G Rosen1, Vijeth Reddy1,*, Amogh Vedantha Krishna1, Peter Abrahamsson2, Jonas Anderud2 1Halmstad University, Functional Surfaces Research Group, 2 Maxillofacial Unit, Hallands Hospital Halmstad,

*E-mail: [email protected]

Keywords: Guided Bone regeneration, Surface topography, Fused Deposition Modeling, PEEK, Optical Interferometer, Areal surface parameters.

Abstract Each manufacturing process produce distinctive surface features and it is important to study these features to understand the surface functional behaviour. Especially in biomedical and dental applications, the importance of surface roughness on implants for cellular growth and integration is extensively researched. The advancement in additive manufacturing and its ability to manufacture using biocompatible materials has paved way for adapting the technology to produce superstructure implants or implant body. Guided bone regeneration (GBR) involves creating space between the bone surfaces and surrounding soft tissues, using a barrier that allows new bone to migrate into the space while preventing other cell types from interfering (1). Apart from providing functional space, the barriers should be capable of integrating with surrounding tissues and stabilize the blood clot which helps wound healing. In this research study, investigations are performed on space- containing barriers produced by Fused Deposition Modeling (FDM) and milling process for guided bone regeneration. The material under study is Polyetheretherketone (PEEK) which is proposed to substitute for metals and ceramics in biomaterials. FDM generates surfaces that are different compared to conventional manufacturing technique and varies with respect to different geometries and process parameters (2,3). The study involves comparisons between the surfaces of 3D printed barriers with its milled counterpart and to identify the influence of respective surface topographies on bone growth. The surfaces are measured using optical interferometer on inner, outer and wall regions of the barriers, as shown in figure 1, and characterized using areal surface parameters defined by ISO 25178-2:2012 (4). The measured samples are surgically attached to the skull of rabbit to study the effective bone growth. Further, areal surface parameters are screened to identify the significant parameters to compare different surfaces and correlate with the growth of bone volume. The results suggest the arithmetic mean height of outer surfaces, Sa of 3D printed PEEK barriers are slightly lower compared to the milled surfaces but higher on inner regions. 33 Abstract submitted to the www.metprops2019.org conference

Figure 1: Barriers for GBR produced by (a) FDM (b) milling

Figure 2: Surface topography of inner surface of (a) 3D printed sample (b) Milled sample

2.50 Arithmetic mean height, Sa 2.00 3D printed PEEK Milled PEEK

1.50

Sa, µm 1.00

0.50

0.00 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 10 Inner surface wall surface outer surface Barrier sample number

Figure 3: Arithmetic mean height, Sa, of barrier surfaces

34 Abstract submitted to the www.metprops2019.org conference

Main References [1] Jonas Anderud (2016), On guided bone regeneration using ceramic membranes (Doctoral Dissertation in Odontology), Malmö university, Sweden. [2] Gibson I, Rosen DW, Stucker B (2010) Additive manufacturing technologies, Springer, New York, https://dx.doi.org/10.1007/978-1-4419-1120-9. [3] Vijeth Reddy, Olena Flys, Anish Chaparala, Chihab E Berrimi, Amogh V, BG Rosen (2018) Study on surface texture of Fused Deposition Modeling, Procedia Manufacturing,Volume 25, Pages 389-396,ISSN 2351-9789, https://doi.org/10.1016/j.promfg.2018.06.108. [4] ISO 25178: Part 2 2012 Geometrical product specifications (GPS)-surface texture; areal part 2: terms, definitions and surface texture parameters (International Organization for Standardization) 35 Abstract submitted to the www.metprops2019.org conference

SESSION 2

36 Abstract submitted to the www.metprops2019.org conference

Conference 034

Influence of surface topography on diffusion bonding of stainless steel parts

Chris Evans1, Brigid Mullany1, Brian K. Paul2, Venkata Rajesh Saranam2, Ali Tabei2, Subhasree Srenevas1 1University of North Carolina at Charlotte, Center for Precision Metrology, 2 School of Mechanical, Industrial and Manufacturing Engineering, Oregon State University

E-mail: [email protected]

Keywords: surface texture, diffusion bonding

Abstract: Diffusion bonding (DB) is a solid-state welding process where the principal mechanism for joint formation is solid-state diffusion between two contacting surfaces. DB removes pores, or voids, stranded between contacting surface topographies. Pore elimination is accomplished via transient plastic flow and sustained creep at elevated bonding temperatures (0.5 to 0.8 of melting point) and high pressures via multiple mass transfer mechanisms. To minimize the require mass transfer (and process time) DB surfaces are typically fine ground, although there are DB applications using cold rolled surfaces.

Models linking surface topography to percent bonded area (PBA) have generally relied on simplified geometric assumptions. The seminal work of Hill and Wallach (1989) assumes surfaces with periodic, long shallow parallel ridges and troughs, akin to grinding, that form extruded elliptical pores y plastically deforming the ridges tip-to-tip. The geometries were characterized using profile Rq values and average wavelength. Such methods correlate to final PBA in some cases, but show substantial errors when in DB of surfaces with fundamentally different structures.

In this work we investigate the effect of surface topography over a wide spatial frequency band on the DB of ground (GR) and cold-rolled (CR) 316 stainless steel (SS316) samples with both GR (GR) and cold-rolled (CR) surfaces with comparable Sq (~0.3 m). Prior to DB, the surfaces are measured using areal scanning white light interferometry (SWLI) systems and a long stroke surface profilometer. Finite element analysis (FEA) models provide insights on how process-induced deformation affects the evolving bondline. PBA is determined using metallography and microscopic analysis of the bond line.

Figure 1 shows typical SWLI surface measurements. The CR surface structure is dominated by plateau regions showing a lay with inter-dispersed pits assumed to result from contact with the surface of the rolls. The GR surface, Fig. 1(c)&(d) consists of the expected directional ridges and troughs.

37 Abstract submitted to the www.metprops2019.org conference

Initial analysis of the surfaces used statistical, hybrid and bearing area curve parameters as defined by ISO 25178-2. All the CR surfaces were segmented to separate the “plateau surface” from pits. The percentage area associated with pits is at most 2.1% (mean =1.8%). Similar analysis on the GR samples found the deepest grinding marks accounted for a similar a percentage. Student t-test analysis of the ISO parameters data indicate that the material volume parameters are statistically different between the GR and CR samples. The CR samples are more consistent, and all four metrics are lower than for the GR surface.

Surface metrology data were imported into FEA code and elastoplastic deformation modelled in contact with a perfect flat surface using a frictional framework was utilized and a coefficient of friction of 0.1. Resulting percentage area contact based on FEA for CR was 30.5% compared to 27.2% obtained by dividing bonding pressure yield strength at temperature. For GR the results are 20.2% and 13.9% respectively. FEA output maps show good agreement with computational truncation of original surface maps.

PBA when bonding chemomechanically polished SS316 samples to CR surface is significantly higher than the GR surfaces. Correlations, and absence thereof, between PBA and parametric analysis of the surfaces will be discussed. Further evaluations of longer spatial wavelength errors and of the deviations from the Hall and Wallach model be presented.

(a) (b) 0.5 m m  417 3.02 mm 3.02

Cold Rolled Cold 2.75 × 20 × (c) (d) m  -1.5 m 417 3.02 mm Ground 2.75 × 20 ×

Figure 1. (a) 2.75× and (b) and 20× of a CR surface, (c) 2.75× and (d) 20× of a GR surface, respectively.

38 Abstract submitted to the www.metprops2019.org conference

Conference 039

Features selection approaches for an objective control of cosmetic quality of coated surfaces

S. Bessonnet 1,4, M. El Mansori1,4, S. Mezghani1, R. Pee4, S. Pinault4 1 Arts et Métiers ParisTech, MSMP Laboratory, Rue Saint Dominique, BP 508, 51006 Châlons-en-Champagne, France 2 Arts et Métiers ParisTech, MSMP Laboratory, Cours des Arts et Métiers, 13617 Aix- en-Provence, France 3 Texas A&M Engineering Experiment Station, College Station, TX 77843, USA 4 ESSILOR International, 63 Boulevard Oudry, 94000 Créteil, France

E-mail: [email protected], [email protected]

Keywords: feature selection, cosmetic quality, surface defects, coating

Abstract The cosmetic aspect is one of the main functions of surfaces in several industrial applications. Even the smallest surface defects may have a critical effect on the cosmetic tolerability of industrial surface. Thus, surfaces are generally coated at the last manufacturing process stage to cover existing defects and ensure their cosmetic requirement. The surface quality is always controlled after coating which lead to a loss of time and increase production costs. This is due to a various flaw patterns and a lack of uncoated surfaces specifications. Hence, the identification of relevant surface morphological parameters underlies an objective and automatic cosmetic control performance. In fact, this relevant parameters selection allows tracking surface flaws during the coating finishing operation. This paper presents a comprehensive overview of various feature selection tools for data analysis (Analysis Neural Network (ANN), ANOVA, Relieff, PAC, …) to extract relevant information out of physical data. A design of experiment based on scratches test on amorphous polymers to generate typical controlled defects has been performed. Then, several cosmetic defects characteristics were extracted from experimental measurements. Feature selection approaches were applied and compared to determine the most relevant parameters. The advantages and limitations of each method for data analysis have been highlighted in the case of real engineering surface quality control.

Main References [1] Gamble M, Mezghani S, El Mansori M, Divo F, Interferometric and microscopic measurements of surface finish appearance evaluations of ophthalmic lens edges, AIP Conference Proceedings 1315 (1), 1353-1358 [2] El Mansori M, Mezghani S, Zahouani H, Divo F, Biomimetic touch perception of edge finish of ophthalmic lens, Wear 301 (1-2), 362-369 [3] Mezghani S, Zahouani H, Piezanowski JJ, Multiscale characterizations of painted surface appearance by continuous wavelet transform, Journal of Materials Processing Technology 211 (2), 205-211 [4] Bessonnet S, El Mansori M, Mezghani S, Pinault S, Multi-scale computation of multistage manufacturing process signatures of glassy polymers multi-functionalisation, Procedia Manufacturing 26, 681-689

39 Abstract submitted to the www.metprops2019.org conference

Conference 071

A characterization framework for freeform surfaces L. Pagani1, W. Zeng1, S. Lou1, F. Blateyron2, X. Jiang1, P. J. Scott1 1University of Huddersfield, EPSRC Future Metrology Hub, 2DigitalSurf

E-mail: [email protected]

Keywords: freeform surface, surface texture, surface characterization, characterization software.

Abstract Precision manufacturing and modern measuring devices lead to new challenges in the measurements of freeform surfaces [1]. The current set of texture parameters defined in ISO 25178-2 [2] are well studied and able to characterize an areal surface measurable by optical devices and profilometers. Figure 1 shows the steps that have to be taken during a surface characterization process. Once the surface has been measured the reference form has to be computed and removed (the unwrapping phase in the figure). Unwrapping means converting the estimated reference form (cylinder, sphere, etc.) into a plane. A filtering operation might follow and finally the surface is characterized. Note that the unwrapping and filtering steps can be swapped if the filter is applied on the freeform surface. Freeform surface may be characterized by complex shape or may presents re-entrant features, these surfaces cannot be properly converted to a height map because the unwrapping operation generally introduce some distortions [3]. In this paper, a framework capable of characterizing surfaces with complex surface is proposed. The method consists in computing the roughness parameters, given a triangular mesh, without unwrapping the reference form surface is presented. The surface is represented by a parametric surface to extend the roughness parameters defined in the ISO 25178-2 to a freeform surface [4]. The triangular mesh approximation is then used to compute the texture parameters values, avoiding the parametrization step to speed up the computational time. Height, hybrid (Sdq and Sdr) and functional parameters (Vmp, Vmc, Vvv and Vvc) were generalized in order to be computed on a non-planar reference surface. The equations of proposed parameters are similar to the ISO parameters, for example the parameter that measures the height variability is: 1 1 , ⇒ , The formulation and the concept of the generalized set of parameters are strictly related to the standard definition. The difference is the form surface, which is represented by a parametric surface, allowing a wider range of surfaces to be described [5]. Figure 2a shows a ball bearing scanned with a computed tomography device, the color represents the distance from the least squares sphere. It is well known that a sphere cannot be transformed into a plane without distortions. Figure 2b shows the computed bearing curves using the proposed approach (Mesh) and after unwrapping the data and converting the data to a height map (Projected). The projection method clearly introduces a bias in the values involving the area and the volume. Using the proposed method, the errors

40 Abstract submitted to the www.metprops2019.org conference

in area and volume computation generated by the unwraping phase can be avoided using the measured mesh.

Figure 1. Surface characterization flowchart

(a) (b) Figure 2. Example of the wearing on a ball bearing (a) and bearing curves (b)

Main References [1] Jiang, X., P. J. Scott, D. Whitehouse and L. Blunt, Paradigm shifts in surface metrology. Part II. The current shift. Proceedings of the Royal Society A, 2007. 463 (2085), p. 2071- 2099. [2] ISO, ISO 25178-2, Geometrical product specification (GPS) - Surface texture: Areal - Part 2: Terms, definitions and surface texture parameters. 2012. [3] Abdul-Rahman, H. S., S. Lou, W. Zeng, X. Jiang, P. J. Scoot, Freeform texture representation and characterisation based on triangular mesh projection techniques. Measurement, 2016. 92: p. 172–192. [4] Pagani, L., Q. Qi, X. Jiang, P. J. Scott, Towards a new definition of areal surface texture parameters on freeform surface. Measurement, 2017. 109: p. 281–291. [5] do Carmo, M. P., Differential Geometry of Curves and Surfaces. Prentice-Hall, 1976.

41 Abstract submitted to the www.metprops2019.org conference

SESSION 3

42 Abstract submitted to the www.metprops2019.org conference

Conference 010

Integral analysis of selective laser melting of intermetallic NiTi and TiAl powder

M. Doubenskaia1, I. Smurov1,2, A. Sova1, P. Petrovskiy2

1Université de Lyon, Ecole Nationale d'Ingénieurs de Saint-Etienne (ENISE), LTDS Laboratory, 58 rue Jean Parot, 42023 Saint-Etienne Cedex 2, France

2National University of Science & Technology (MISIS), 4 Leninsky pr., 119049, Moscow, Russia

E-mail: [email protected]

Keywords: selective laser melting, intermetallic, optical diagnostic, thermal cycling.

Abstract Selective laser melting technology (SLM) is applied to develop samples from nickel-titanium (NiTi) powder using preheating of the entire manufacturing module up to 600°C (to reduce thermal gradients) and different substrate materials: 304L, Ti-6Al-4V, Inconel 718 [1]. It is found that the composition and properties of the substrates influence the resulting porosity and eventual cracking of NiTi samples [2]. The combination of the “two zones” and “criss-cross” SLM strategies is defined as the optimal one [3]. The dominant phase of the obtained parts is NiTi B2 austenite. Some minor picks of R martensite phase are detected, as well as the formation of Ni4Ti3 precipitates. The microstructure of the samples is the austenitic one with martensite-like zones of the R phase. Martensitic structure is found inside the cracks. Mechanical properties of the samples are measured by nanoindentation. SLM of intermetallic Ti–48Al–2Cr–2Nb powder is studied using different and complementary methods: (a) experimental parametric analysis (variation of laser power, beam scanning velocity, etc.); (b) metallography including XRD and EDS; (c) optical monitoring by IR-camera and (d) mathematical modeling. Preheating of manufacturing module up to 450 °C is applied before and during samples manufacturing. Two substrate materials are used: Steel S235 and pure Al. Resulting porosity versus SLM processing parameters is analyzed. The average microhardness of the manufactured samples varies in the range of 540-560 HV0.3. XRD analysis shows domination of the α2-Ti3Al phase in the initial powder, heat treated powder before SLM and in developed samples. Some minor peaks of γ-TiAl are found in SLM processed parts. EDS analysis confirms the effect of Al evaporation, which intensifies with laser input energy. IR-camera is used for optical diagnostics of a single track formation. The geometry of the thermal emission field and the heat affected zone (HAZ) versus processing parameters are analyzed. The intensification of hydrodynamic instabilities and material rejection from the zone of powder consolidation with beam scanning velocity is found. The evaporation of Al is clearly detected by the IR-camera for elevated laser input [4].

43 Abstract submitted to the www.metprops2019.org conference

Mathematical modeling shows that the same elementary volume of SLM sample can be remelted several times during its fabrication, depending on the SLM processing parameters and strategy of beam scanning. The maximum calculated cooling rates are of the order of 106 °C/sec.

References [1]. Elahinia, M. H., Hashemi, M., Tabesh, M., Bhaduri, S. B., 2012. Manufacturing and processing of TiNi implants: A review, Prog. Mater. Sci., 5(57), 911-946. [2]. Dadbakhsh, S., et al., 2016. Texture and anisotropy in selective laser melting of NiTi alloy, Mater. Sci. Eng.: A, 650, 225-232. [3]. Yadroitsev, I., Bertrand, Ph., Smurov, I., 2007. Strategy of manufacturing components with designed internal structure by Selective Laser Melting of metallic powder, Appl. Surf. Sci., 254 (4), 980-983. [4]. Everton, S. K., Hirscha, M., Stravroulakis, P., Leach, R. K., Clare, A.T., 2016. Review of in- situ process monitoring and in-situ metrology for metal additive manufacturing, Mater. Design, 95, 431-445.

44 Abstract submitted to the www.metprops2019.org conference

Conference 049

Multiscale characterization of mass finished rings: a comparison of geometric and bandpass filtering methods

T Bartkowiak1, B Gapiński1, K Grochalski1, M Wieczorowski1 1Institute of Mechanical Technology, Poznan University of Technology

E-mail: [email protected]

Keywords: surface texture, mass finishing, multiscale

Abstract The fundamental issue in surface metrology in to provide methods that can allow establishing correlations between measured topographies and performance or processes, or can discriminate confidently topographies that were processed, or that perform, differently [1]. This article presents a set of topographies from mass finished steel rings, measured by Hommel T8000 3D contact profilometer [2]. Data was captured from four different regions of top, bottom, inner and outer surfaces individually. The rings were manufactured by drop forging and hot rolling. Final surface texture was achieved by mass finishing with spherical ceramic media or cut wire. In this study, we compare two different multiscale methods: sliding band pass filtering and multiscale curvature tensor approach. In the first method, we used conventional height and hybrid parameters evaluated as a function of central wavelength and bandwidth for measured textures [3]. In the latter, we calculated multiscale tensor statistics for a range scales from original sampling interval to its twenty times multiplication [4]. These characterization parameters were then utilized to determine how confident we can discriminate (through F-test) topographies between regions of the same specimen and between topographies resulted from processes of various technological parameters. We then regressed technological parameters with calculated characterization parameters, for the set of scales for which we could confidently discriminate. We noticed that different aspects of the surface topographies could be influenced by processing depending on the scale.

45 Abstract submitted to the www.metprops2019.org conference

a) b)

Figure 1. Sample of a mass finished ring: a) top view, b) measured topography

Figure 2. Estimated mean curvature (H) calculated at scale equal to 60 µm for two mass finished surfaces created with various process parameters

Figure 3. Results of F-test for discriminating using standard deviation of minimal curvature (κ1q) – probability versus scale

Main References [1] Brown CA, Hansen HN, Jiang XJ, Blateyron F, Berglund J, Senin N, Bartkowiak T, Dixon B, Le Goic G, Quinsat Y, Stemp WJ (2018) Multiscale analyses and characterizations of surface topographies CIRP annals 67 2 pp.839-862 [2] Pawlus P, Wieczorowski M, Mathia T (2014) The errors of stylus methods in surface topography measurements, ZAPOL, Szczecin, Poland. [3] ISO 25178-2. Geometrical product specifications (GPS)—Surface texture: Areal—Part, 2. [4] Bartkowiak T, Berglund J, Brown CA (2018) Establishing functional correlations between multiscale areal curvatures and coefficients of friction for machined surfaces Surf. Topogr.: Metrol. Prop. 6 034002

46 Abstract submitted to the www.metprops2019.org conference Conference 053

Polishability of coatings – a case study

B-G Rosen1, S Rebeggiani1, Simon Palm2 1Halmstad University, The Functional Surfaces Research Group, Sweden; 2Volvo Car Corporation, Gothenburg, Sweden

E-mail: [email protected]

Keywords: polymer coating, surface evaluation, end-of-line repair

Abstract The surface finish of a vehicle plays a major role on the perceived product quality, and is the first thing a potential buyer sees. Therefore, it is of great importance to secure a homogeneous and defect free surface finish. Today, most car and truck bodies undergo end-of-line repairs, i.e. local abrasive polishing to eliminate spot defects, which can lead to other types of defects. The occurrence of the later depend on a combination of the coating system and applied process parameters – and the possibilities to notice them. In this study, process data based on manual polishing was collected to get a better understanding of how different polishing strategies link to achieved surface finish. The best strategy was translated to be used in one for the purpose developed CNC-machine (see figure 1, left and mid), where different coating systems can be tested in terms of applied forces, tool combinations and tool paths. Two types of visual estimations were performed to estimate the surface quality; one where the samples were graded when placed in a light box one by one illuminated by D65 light (i.e. simulated average daylight [1]) [2], and one where a Summerscale estimation were performed were all samples were compared to each.

Collected process data is based on 10 polishers, all working with end-of-line repairs in the production, who made four ‘repairs’ on 2 samples each in a lab environment (see figure 2). Applied forces and tool paths were measured continuously, and analysed afterwards. As expected, the results showed strategy variations, both between different workers, and between the workers themselves. Table 1 summarizes the test results; • Step1: Sanding – to eliminate the small defect. A short time (5-10 s), low force and ‘gentle’ handling needed to avoid dents, sharp edges and overheating. • Step 2: Rubbing – to eliminate the sanding scratches. • Step 3: Polishing – to restore the surface appearance to the same quality level as the non-repaired surrounding areas. Longer rubbing and polishing times in combination with higher forces seemed to generate acceptable surface finishes, i.e. no visible scratches and polishing roses. However, the results did not show a clear strategy leading to good results,

47 Abstract submitted to the www.metprops2019.org conference

rather that different set of process parameters could be used. The first CNC-tests showed the importance to use a low sanding force; a harder foam used in the beginning made it impossible to avoid larger forces due to height variations of samples and table. Therefore, a softer foam was used to get a wider height range within the same force span. It could also be concluded that the CNC-machine enables repeatable test procedures for evaluations of the polishability of coating systems. Further tests with the CNC-machine will be performed to optimize the final polishing step, and to test other tool combinations for softer coting systems.

48 Abstract submitted to the www.metprops2019.org conference

Figure 1. Left; a sketch of the CNC-machine, further explained in []. Mid; tool mounted on the CNC- maching during the final polishing step include the force plate collecting applied force and patterns. Right; set-up for Summerscale estimations.

Figure 2. The experimental set up where the manual workers’ data were collected; the black sample is placed on a force board with three sensors for horizontal forces.

Table 1. Summary of the process data based on the manual polishers’ strategies.

Step Force [N] Time [s] Runs Path 1 - Sanding (wet/dry) 1-30 2-12 1 Circular 2 - Rubbing 5-60 5-35 1-3 Random / structured 3 - Polishing 5-50 10-50 1-3 Random / structured

Main References [1] D65: ISO 10526:2007 (CIE S 014-2/E:2006) CIE standard illuminants for colorimetry [2] S Rebeggiani et al 2018 Surf. Topogr.: Metrol. Prop. 6 024009

49 Abstract submitted to the www.metprops2019.org conference

Conference 011

Surface characterisation with light scattering and machine learning

Mingyu Liu1, Nicola Senin1, 2, Richard Leach1 1Manufacturing Metrology Team, Faculty of Engineering, University of Nottingham, Nottingham, UK 2Department of Engineering, University of Perugia, Italy

E-mail: [email protected]

Keywords: characterisation, surface, light scattering, machine learning

Abstract Light scattering technology has been intensively investigated for surface measurement [1, 2]. However, most of developments have focused on the estimation of roughness indicators via area integrating methods, while, due to the high nonlinearity of the scattering process, few have addressed the challenge of reconstructing the actual topography, which implies solving a more complex inverse problem. In this study, rather than attempting to obtain a full reconstruction of surface topography from light scattering data, a novel approach is proposed to use light scattering information combined with machine learning to discriminate amongst different topographies. This is useful not only to compare surfaces, but also to automatically detect any type of undesired variation in manufacturing, e.g. the appearance of defects, or any other type of drift. The preliminary solution presented here operates on 2D geometry (topography profiles) and 2D light scattering far fields, investigating performance and behaviour purely via simulation. First, virtual models of different classes of surface topographies are artificially generated and labelled. Then, the far field scattering signals are obtained by simulation under different conditions of incident light through a boundary element method (BEM) [3, 4]. The scattering signals are used as the training datasets for a machine learning system, based on neural networks (NNs) [5], to implement an automated multi- class classifier. With the trained classifier, new observed surfaces can be classified with high accuracy using the associated far field scattering result. Preliminary experiments have been conducted to characterise three types of grating surfaces (blaze, sinusoidal and square gratings). The NN was designed as a three-layer densely connected network. In the experiment, 3300 datasets (3000 for training, 300 for testing) were used, consisting of gratings with different spacings. For the case studies, the accuracy of classification (number of correct predictions over number of total predictions) was higher than 99%. The results demonstrate that the proposed method is effective for discrimination of surfaces classes. For future work, the proposed method will be verified with scattering measurements of real surfaces. The method will also be implemented for defect detection in different kinds of surfaces and a 3D version of BEM model will be developed and utilised for characterisation of 3D surfaces.

50 Abstract submitted to the www.metprops2019.org conference

Figure 1. Schema of the proposed method.

Figure 2. Typical profiles for (a) blaze grating, (b) sinusoidal grating, and (c) square grating, and simulated far field results for (d) blaze grating, (e) sinusoidal grating, and (f) square grating.

Main References [1] Leach RK. Optical measurement of surface topography: Springer, 2011. [2] Stover JC. Optical scattering: measurement and analysis, third edition: SPIE Press, 2012. [3] Simonsen I. Optics of surface disordered systems. European Physical Journal Special Topics. 2010;181:1-103. [4] Warnick KF, Chew WC. Numerical simulation methods for rough surface scattering. Waves in Random Media. 2001;11:R1-R30. [5] LeCun Y, Bengio Y, Hinton G. Deep learning. Nature. 2015;521:436.

51 Abstract submitted to the www.metprops2019.org conference

SESSION 4

52 Abstract submitted to the www.metprops2019.org conference

Conference 013

Multiscale Analysis of Pavement Texture - Effect on Adhesion

W Edjeou1, 2, V Cerezo2, H Zahouani3, F Salvatore4 1 Central School of Nantes, 2 French Institute of Science and Technology in Transportation, Planning and Networks, 3 Central School of Lyon, 4 National School of Engineers of Saint-Étienne.

E-mail : [email protected]

Keywords: surface texture, multiscale analysis, wavelet, Adherence.

Abstract

The surface properties (adhesion, rolling noise and rolling resistance) of road surfaces are closely related to the texture (Macrotexture and Microtexture) of the surfaces[2]. Several scales of texture intervene in the interaction between a tire and the roadway. However, the influence of each scale on these properties is as for him little or not known. Characterization of roughness requires field measurements, with or without contact, which are generally complicated to implement and costly. The advent of new technologies has opened the door to more accurate and less expensive in situ measurement methods (such as microscopes). These measuring means enable us to extract surface profiles in the form of a signal. The wavelet-based multiscale analysis will be applied to the extracted signals to evaluate the weight of each scale on the properties of these surfaces.

The choice of the wavelet function has a great influence on the decomposition results[4]. The primary objective of this study will be to determine the wavelet function (s) suitable for multiscale analysis of pavement surfaces.

In a second step, a reduced number of road surfaces will be selected and their surfaces will be mapped in 3D with an adequate level of precision. This will allow on the one hand to identify the relevant scales and on the other hand, to establish relationships between the texture and the different properties studied. This step will define the testing and treatment methodology to be implemented (magnification, filtering, sampling, etc.).

A comparison between the wavelet-based multiscale decomposition method and other conventional methods[1] such as filtering, Fourier analysis or multiple measurements at different magnifications will be made.

53 Abstract submitted to the www.metprops2019.org conference

Figure 1. The decomposition of profile by inverse wavelet transform [3]

Figure 2. Microtexture and macrotexture [1]

Main References [1] C. A. Brown, H. N. Hansen, X. J. Jiang, F. Blateyron, J. Berglund, N. Senin, T. Bartkowiak, B. Dixon, G. Le Goïc, Y. Quinsat, W. J. Stemp, M. K. Thompson, P. S. Ungar, and E. H. Zahouani. 2018. Multiscale analyses and characterizations of surface topographies. CIRP Annals - Manufacturing Technology, 839–862. [2] M.-T Do. 2004. Contribution des échelles de texture routière à l’adhérence des chaussées. [3] S-H. Lee, H. Zahouani, R. Caterini, and T.G. Mathia. 1998. Morphological characterisation of engineered surfaces by wavelet transform. Int. J. Mach. Tools Manufact, 581–589. [4] S. Mezghani, L. Sabri, M. El Mansori, and H. Zahouani. 2011. On the optimal choice of wavelet function for multiscale honed surface characterization.

54 Abstract submitted to the www.metprops2019.org conference Conference 064

An exploration of motifs parameters using watershed segmentation and morphological envelopes

F Blateyron1, B Leroy2 1 Digital Surf, France, 2 Peugeot-Citroën SA, France

E-mail: [email protected]

Keywords: surface texture, motifs, watershed segmentation

Abstract (Background) R&W motifs (ISO 12085) have been widely used for around 40 years, mainly in France. It is one of the rare methods that have been supported by a huge campaign of functional correlation involving more than 40,000 profile measurements. However, its relative instability and the complexity of its implementation due to numerous special cases have prevented a wider adoption outside Europe. Recent developments made it possible to improve the method by using watershed segmentation and morphological envelopes. These new methods are about to be included in the new revision of profile standards (ISO 21920) but they barely have been compared to the original method. (Methodology) In this study, watershed segmentation is applied on profiles, and several pruning methods are tested. Values of the R parameter obtain in each configuration are compared with the original R&W values on a series of 150 industrial profiles. Cases where divergence exist are then explored visually and explained from the functional requirement, sometimes underlining problems in the original method. Secondly, several filtration protocols are tested, using mean-line or envelope filters, to remove form and/or waviness prior to the motif analysis and obtain better results on roughness motifs parameters. Finally, a subset of profiles is tested for robustness against profile inversion or lateral shift. (Results) The first results show that it is possible to find a combination of settings that allow comparable values with the original R&W method. Results obtained on nominally flat profiles show a very strong linear correlation between the watershed segmentation and the R&W method. Profiles with form and waviness require an adapted pruning value. Interestingly, the interpretation of differences is of great help to understand how motifs should be detected and how associated parameters can correlate to certain functions. (Conclusions) These first results show that watershed segmentation can be used as an alternative to the R&W method, by carefully choosing pruning parameters and by prefiltering profiles. Suitable configurations are described. (Future work) More developments and tests are required to find a general rule for pruning, and to establish an adequate protocol for the analysis of waviness motifs and for the generation of the upper envelope. It is important to continue these developments to provide users with a method that is not based on the mean line but on the upper envelope which is often more significant in tribology and in functional requirements in mechanics.

55 Abstract submitted to the www.metprops2019.org conference

Conference 016

Development of a novel method to characterize mean surface peak curvature of dental implant surfaces

A Zabala1, L Blunt2, A Aginagalde1, I Llavori1, Naiara Rodriguez-Florez1, W Tato1 1Mondragon University, Surface Technologies Research Group, 2University of Huddersfield, EPSRC Advanced Metrology Hub

E-mail: [email protected]

Keywords: dental implant, implant integrity, surface topography, feature parameters, surface curvature

Dental implant surface integrity may be compromised during surgical insertion due to the stresses generated by the mismatch between the implant diameter and the osteotomy, which may lead to wear and topographical modifications on the post-inserted dental implants. The surface of modern implants with increased roughness presents higher peaks that are potentially more likely to break off and detach during the insertion procedure into bone [1]. The presence of titanium particles on the peri-implant area has been associated with an increased early bone loss and to a greater risk of periimplantitis [2, 3]. Accordingly, the study and development of novel surface modification predictive models is of great importance. The topography of typical dental implant surface treatments were analysed: control machined surface (MCN), two different acid etching treatments (AE1, AE2) and a sand blasting followed by acid etched surface (SB+AE). Areal topographical characterization (3D) was carried out through confocal profilometry. Based on the wear and plasticity index models [4], it is anticipated that the surface mean curvature would play an important role in the correlation between 3D topographical parameters and the modification of dental implant surfaces generated during implant insertion. Visual inspection of the measured 3D topographies demonstrated that the feature curvature parameters belonging to ISO 25178-2 [5] calculated by MountainsMap® (Spc, Ssc) were not representative of the surface curvature properties. In the light of the lack of correlation encountered, this work presents an alternative novel method to characterize mean surface peak curvature which is based on the root mean square slope parameter (Sdq). The rationale behind the approach is based on the fact that the mean slope of the surface as a function of height changes more rapidly in surfaces with sharp peaks compared to those with rounded peaks (Figure 1a). The method is based in the following steps (Figure 1b): (i) the evolution of the root mean square slope of the surface (Sdq) is calculated as a function of progressive truncation heights, and (ii) the slope of the evolution curve is calculated to obtain the proposed parameter, named as ΔSdq. The ΔSdq parameter presented stable values for all surfaces under study (coefficient of variation lower than 11 %). Based on visual inspection of the surfaces it could be observed that unlike Spc and Ssc parameters, the proposed ΔSdq parameter represented the relative surface curvature properties (Figure 2), and therefore it is presented as an alternative method to characterize mean surface peak curvature. Future studies will analyse the correlation between the modification of dental implant surfaces generated during surgical placement and 3D topographical parameters, and it is anticipated that the mean surface peak curvature will present an important role.

56 Abstract submitted to the www.metprops2019.org conference

Figure 1: Summary of the presented alternative novel method to characterize surface curvature. (a): Rationale behind the approach, illustrative representation of the evolution of the local slope in function of height for a rounded and a sharp peak; (b): Schematic representation of the evolution of the local slope (Δ Sdq) calculation. Increasing truncation levels htr are applied and the Sdq is calculated at each remaining upper surface obtaining the Sdq evolution curve. Finally, the slope of the curve is calculated to obtain the alternative ΔSdq parameter.

57 Abstract submitted to the www.metprops2019.org conference

µm µm µm 4 12 30 3 8 20 2 1 4 10 0 0 0

Figure 2: Summary of the results. (a): Representative zoom images of the four surface treatments under study and corresponding 2D profiles (NOTE: profiles are depicted at the same scale for comparison purposes). (b): Result of the feature curvature parameters (Ssc, Spc) calculated through MountainsMap® not presenting a good correlation with the curvatures observed in (a); (b): results of the newly developed mean surface peak curvature representative ΔSdq parameter for the four surfaces under analysis presenting a good correlation with the curvatures observed in (a).

Main References [1] Senna P, Antoninha Del Bel Cury A , Kates S, and Meirelles L. Surface damage on dental implants with release of loose particles after insertion into bone. Clin. Implant. Dent. R., vol. 14 4 pp 681- 692, 2013. [2] Wilson Jr TG, Valderrama P, Burbano M, Blansett J, Levine R, Kessler H, and Rodrigues DC. Foreign bodies associated with peri-implantitis human biopsies. J. Periodontol. 86 1 pp 9-15, 2015. [3] Mendonca DBS, Cooper L , Mendonca G, and Dechichi P. Effects of titanium surface anodization with cap incorporation on human osteoblastic response. Mater. Sci. Eng. R: C, 33 4 pp. 1958- 1962, 2013. [4] Jackson RL and Green I. On the modelling of elastic contact between rough surfaces. Tribol. T. 54 2 pp 300-314, 2011. [5] ISO 25178-2:2012 Geometrical product specifications (GPS). Surface texture: Areal Part 2: Terms, definitions and surface texture parameters, 2012.

58 Abstract submitted to the www.metprops2019.org conference

Conference 019

A topographical analysis based on three transformations

R Vayron1, C David2, R Deltombe1, F Robache1, G Le Goic3, M Bigerelle1 1 Université Polytechnique Hauts de France, Laboratoire d’Automatique, de Mécanique et d’informatique Industrielles et Humaines, LAMIH UMR CNRS 8201, 59300, Valenciennes, France. 2 APERAM R&D -Isbergues, France 3 Laboratoire LE2I, FRE2005 CNRS ENSAM, Univ. Bourgogne Franche-Comté, Auxerre, France

E-mail: [email protected]

Keywords: surface topography, stainless steel, roughness, brightness, cold rolling.

Abstract Stainless steels are interesting materials because they satisfy several types of needs in the industry by their hygienic and aesthetic properties, and of course their corrosion resistance. In addition to high performance mechanical properties, stainless steels are fully recyclable and show remarkable functional properties (biocompatibility, cleaning, shaping) for a low cost/benefit ratio requiring low maintenance. As a result, stainless steels become a basic material for a multitude of manufactured goods industries covering an extremely large scope of applications ranging from architecture to jewelery. One of the criteria for satisfying customer requirements is the aesthetic aspect, which must be flawless. In order to achieve that, the control of manufacturing process is extremely important. In some rare cases, it can be possible to observe areas of the surface with inhomogeneous visual aspect after cold-rolling. The aim of this study is to analyze the topography of such regions (hereafter referred to as zones A and B), and to understand the phenomena inducing this aspect. Therefore, different areas of stainless steel have been measured with Bruker ContourGT device associated with 20x lens. Ten measurements are performed on each type (A and B areas). Each measurement area is described by a square of 300µm by 300µm built by 63 elementary surfaces. Classical multi-scale topographic [1] (Wavelet [2], Modal [3] and Fourier [4] transform) analyzes have been performed and all classical topography parameters have been calculated but the entirety results show no significant differences between zones A and B using a method described in [5] thanks to bootstrap protocol [6]. Then, 12 different map transformations were then performed to determine the cause of this change in appearance (curvatures, gradients [7]). Many post-treatment protocols were tested and only one storyline of transformation allowed to distinguish zones A and B. This solution breaks down into three stages. In a first step, a high pass filter with an appropriate cut off was applied (Figure 1, left). Then in a second step, a gradient transformation was computed perpendicular to the rolling process (Figure 1, right). Finally, a segmentation is performed to quantify the topographical measure of each pattern (Figure 2). As a result, the area of pattern becomes a discriminant parameter and can be linked to local plastic deformation during the rolling process.

59 Abstract submitted to the www.metprops2019.org conference

Figure 1. Filtered surfaces (left) and X-gradient transformation (right).

Figure 2. Segmentation of surface A and B after post-treatment (HP Filtering and gradient calculation) to distinguish significantly the both pattern areas.

Main References [1] Brown, C. A., Hansen, H. N., Jiang, X. J., Blateyron, F., Berglund, J., Senin, N. et al. (2018). Multiscale analyses and characterizations of surface topographies. CIRP annals, 67(2), 839-862. [2] Zahouani, H., Mezghani, S., Vargiolu, R., & Dursapt, M. (2008). Identification of manufacturing signature by 2D wavelet decomposition. Wear, 264(5-6), 480-485.

60 Abstract submitted to the www.metprops2019.org conference

[3] Le Goic, G., Favreliere, H., Samper, S., & Formosa, F. (2011). Multi scale modal decomposition of primary form, waviness and roughness of surfaces. Scanning, 33(5), 332- 341. [4] Deltombe, R., Kubiak, K. J., & Bigerelle, M. (2014). How to select the most relevant 3D roughness parameters of a surface. Scanning: The Journal of Scanning Microscopies, 36(1), 150-160. [5] Le Goïc, G., Bigerelle, M., Samper, S., Favrelière, H., & Pillet, M. (2016). Multiscale roughness analysis of engineering surfaces: a comparison of methods for the investigation of functional correlations. Mechanical Systems and Signal Processing, 66, 437-457. [6] Bigerelle, M., Marteau, J., & Blateyron, F. (2017). Assessing the discriminating power of roughness parameters using a roughness databank. Surface Topography: Metrology and Properties, 5(2), 025002. [7] H'roura, J., Bekkari, A., Mammass, D., Bouzit, A., Mansouri, A., Roy, M., & Le Goïc, G. (2017, May). 3D objects descriptors methods: Overview and trends. In Advanced Technologies for Signal and Image Processing (ATSIP), 2017 International Conference on (pp. 1-9). IEEE.

61 Abstract submitted to the www.metprops2019.org conference

Conference 072

Strong functional correlation with wetting using multiscale topographic analyses and characterizations

R J Daniello, A J Frewin, C A Brown Surface Metrology Lab, Worcester Polytechnic Institute

E-mail: [email protected]

Keywords: surface texture, superhydrophobic, wetting, contact angle, correlation, multiscale

Abstract: Superhydrophobicity results from the combination of chemical hydrophobicity and microscale topography. While the role of surface structure and hierarchical scales are often cited1,2, predictive models of wetting behavior are rather limited, especially for surfaces with irregular or stochastic features. The ultimate objective of this work is to develop predictive models for a priori estimation of wetting behaviour when the topography and chemistry of the surface are known. The present study applies multiscale characterizations and regression analyses to understand the wetting of superhydrophobic surfaces. Specimens were prepared in PDMS using a soft lithography techniques based on sandpaper roughness. Wetting was quantified by the advancing and receding contact angles formed by the drop at the contact line between the liquid and solid phases. A strong correlation was observed with area-scale complexity and approaching contact with an R² of 0.99 in a scale range of 2 to 100 μm2.

62 Abstract submitted to the www.metprops2019.org conference

Figure 1. Advancing contact angle vs. area-scale complexity at 4.66 um2. Strong correlation between advancing contact angle and area-scale complexity was observed up to scales of 100 um2.

Main References [1] 1.Gao, L and McCarthy, T,J. 2006, The “Lotus Effect” Explained: Two Reasons Why Two Length Scales of Topography Are Important, Langmuir, 22 2966-2967. [2] Koch, K., Bhushan, B., Jung, Y. C., and Barthlott, W. 2009 Fabrication of artificial Lotus leaves and significance of hierarchical structure for superhydrophobicity and low adhesion, Soft Matter, 5, 1386-1393.

63 Abstract submitted to the www.metprops2019.org conference

SESSION 5

64 Abstract submitted to the www.metprops2019.org conference

Conference 029

Areal surface topography representation of as-built and post- processed samples produced by powder bed fusion using laser beam melting (PBF-LBM)

Olena Flys1,2, Amogh Vedantha Krishna1,, Vijeth V Reddy1, Johan Berglund3,4 and B-G Rosen1 1Halmstad University, Functional Surfaces Research Group, Halmstad, Sweden. 2Research Institutes of Sweden (RISE), Borås, Sweden. 3Chalmers University of Technology, 41296 Göteborg, Sweden 4Swerea IVF, PO Box 104, 43153 Mölndal, Sweden

E-mail: [email protected]

Keywords: Additive manufacturing, Selective laser melting, Shot-blasting, Surface metrology and characterization, Power spectral density, Areal surface texture parameters, Profilometer.

Abstract: The increasing interest in Additive Manufacturing (AM) is due its huge advantage in producing parts without any geometrical limitations. The metal powder bed fusion by laser beam melting (PBF-LBM) has widened the scope as it is capable of producing fully functional metallic components. At the moment, AM compliments the conventional manufacturing methods by providing an opportunity to fabricate complex shapes and lightweight structures which otherwise would be unrealisable. It is due to this reason, AM is extensively utilized in automotive, aerospace, medical and dental applications. Despite their popularity, AM has not fully replaced tradition methods mainly due to the inferior surface quality and poor dimensional accuracy [1,2]. Hence, AM is always followed by a subsequent post-processing step to produce the end- product. In order to establish control over the surface quality it is first necessary to fully understand the surface behaviour in relation to the factors affecting it. In this paper, the focus is mainly on having a better understanding of the surfaces by using advance characterization techniques. The paper documents the influence of build inclination on surface topography and identifies a new approach to select the significant areal surface texture parameters for characterization of complex surfaces [3,4]. Finally, this paper documents the effect of post-processing by analysing the power spectral density plots [5,6]. Truncheon artefact with varying build orientation from 0° to 90° in steps of 3° increment was utilized, which establishes most of the surface conditions (see figure 1). Surface analysis were carried out on 316L stainless steel samples produced by PBF-LBM. The surfaces were measured in both as-built and post-processed conditions using Stylus Profilometer (see figure 2). Shot blasting was the post-processing method chosen for this study. Figure 3a and 3b represents the frequency spectrum of as-built and shot- blasted surfaces at all the build inclinations respectively. Figure 4 represents the difference in the two-frequency spectrums and analysing this frequency spectrum can reveal the effects of post processing. Results suggests that shot-blasting influences the surface changes in all the frequency regions. Also, the parameters that correspond to those frequency regions in figure 4 can prove very effective for characterization. Further the paper can be strengthened by exploring other characterization methods, for instance, fractal analysis can be used to identify the surface effects at different scales and the

65 Abstract submitted to the www.metprops2019.org conference

relationship between the surface appearance and shot-blasting parameters can be studied.

Figure 1. The truncheon artefact with build orientation varying from 0° to 90°.

Figure 2. 3D view of the surface at various build inclinations (a) as-built surfaces (b) shot-blasted surfaces.

Figure 3. Power spectral density plots of all the build inclination angles (a) As-built surfaces (b) shot- blasted surfaces.

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Figure 4. Power spectral density plot depicting the difference in the frequency spectrum of as-built and shot blasted surfaces at all the build inclinations (0° to 90°).

Main References [1] A. Townsend, N. Senin, L. Blunt, R. Leach and J. Taylor, "Surface texture metrology for metal additive manufacturing: a review", Precision Engineering, vol. 46, pp. 34-47, 2016. [2] A. Thompson, N. Senin, C. Giuska and R. Leach, “Topography of selectively laser melted surfaces: a comparison of different measurement methods,” CIRP Ann. 66(1), 543–546, 2017. [3] ISO 25178-2 2012 Geometrical Product Specifications (GPS) — Surface texture: Areal—Part 2: Terms, Definitions and Surface Texture Parameters (Geneva: International Organization for Standardization). [4] R. Leach, Characterisation of Areal Surface Texture. Heidelberg: Springer, 2013. [5] A. Duparré , J.Ferre-Borrull, S. Gliech, G. Notni, J. Steinert and J. M. Bennett, “Surface characterization techniques for determining the root-mean-square roughness and power spectral densities of optical components”, Appl. Opt. 41 154–71, 2002. [6] T. Jacobs, T. Junge and L. Pastewka, “Quantitative characterization of surface topography using spectral analysis”, Surf. Topogr.: Metrol. Prop. 5 013001, 2017.

67 Abstract submitted to the www.metprops2019.org conference Conference 032

Investigations on modeling and visualization of surfaces produced by Fused Deposition Modeling

Olena Flys1,2, Vijeth Reddy1,*, Amogh Vedantha Krishna1, B-G Rosen1 1Halmstad University, Functional Surfaces Research Group, Halmstad, Sweden 2RISE, Research Institutes of Sweden, Borås, Sweden

*E-mail: [email protected]

Keywords: Surface topography, Fused Deposition Modeling, stylus profilometer, areal surface parameters, modeling.

Abstract Fused Deposition Modeling (FDM) is one of the promising additive manufacturing technologies which primarily are used for rapid prototyping. But with the technological advancements, FDM is swiftly moving towards rapid manufacturing exploring new possibilities with respect to part geometries and materials. FDM generates surfaces that are different compared to conventional manufacturing technique and varies with respect to different geometries and process parameters [1, 2]. It is important to study the surfaces produced by FDM to develop a fundamental understanding of the process and identify the effects of different process parameters. In this research study, the effect of process settings and build inclination on the surface topography is analyzed and the results are used for the development of 3D-mathematical surface-topography model. Modeling and simulations of these surfaces helps to predict and visualize surfaces produced at different process settings that can further help develop application specific surfaces or to interpret the post-processing requirements [3, 4, 5]. Investigations include FDM manufactured artefacts at different layer thickness, print infill, print speed and build inclination. The study sample’s surface topography is measured using stylus profilometer and characterized using spectral analysis. This empirical investigation forms the basis for the mathematical 3D model of surface roughness of FDM surfaces. In order to validate the model for surface topography, the value of surface parameters has been calculated through experiments and compared with data predicted through mathematical model. The surfaces at lower build angle between 1° and 20°are the combination of printing effects called ‘stair stepping’ and ‘raster pattern’, as shown in figure 2. Comparison of surface parameters value for modelled and measured surfaces is found to be in good agreement. However, some deviation has been noted between predicted and experimental results of surface parameters with lower build angle.

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1.Filament width 2. Contour (perimeter) width 2 3.Layer thickness 4.Raster angle 5 Build angle

3 5

Figure 1: Model of FDM printed surface. The sketch illustrate the top and the side view of printed surface with some inclination

Figure 2: FDM surfaces at different layer thickness and build inclination

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Main References [1] Gibson I, Rosen DW, Stucker B (2010), Additive manufacturing technologies, Springer, New York, https://dx.doi.org/10.1007/978-1-4419-1120-9. [2] Vijeth Reddy, Olena Flys, Anish Chaparala, Chihab E Berrimi, Amogh V, BG Rosen (2018), Study on surface texture of Fused Deposition Modeling, Procedia Manufacturing,Volume 25, Pages 389-396,ISSN 2351-9789, https://doi.org/10.1016/j.promfg.2018.06.108. [3] R. G. Sargent (2013), Verification and validation of simulation models J. Simul., vol. 7, no. 1, pp. 12–24, 2013. [4] D. Ahn, J.-H. Kweon, S. Kwon, J. Song, and S. Lee (2009), Representation of surface roughness in fused deposition modeling, Journal of Materials Processing Technology, vol. 209, pp. 5593-5600, ISSN 0924-0136, https://doi.org/10.1016/j.jmatprotec.2009.05.016 [5] Omar A. Mohamed, Syed H. Masood, Jahar L. Bhowmik (2015), Optimization of fused deposition modeling process parameters: a review of current research and future prospects, Adv. Manuf, pp. 42–53. 70 Abstract submitted to the www.metprops2019.org conference

Conference 035

Surface defect detection and quantification using statistical based metrics

F Azimi1, B Mullany1 1University Of North Carolina at Charlotte, USA, Center for Precision Metrology. E-mail: [email protected], [email protected]

Keywords: Surface defects, evaluation, polar plots

Abstract The nature and quality of a component’s surface affects its final functionality, expected life span, and perceived value. The economic advantage gained by achieving the desired surface quality drives interest in methods capable of detecting and quantifying surface topography features. A new statistically based approach capable of providing insights on the overall surface topography, and both detecting and quantifying geometric surface features such as scratches or pits will be explained. In the approach an areal map of the surface is considered as a set of constituent profiles, i.e. each column of data is considered as a single profile. The Rq values of these profiles, along with their associated standard deviation values are calculated; the surface is rotated 1° and the process repeated until the surface measurement is rotated through 360°. The standard deviation of the Rq values at each rotational angle is presented in a polar plot format, see figure 1. From the resulting polar plot it is possible to detect and characterize surface characteristics such as directionality, periodicity, isolated scratches and digs [1,2]. See figure 2 for some examples of how the polar polar varies with surface topography. To characterize and quantify multiple uniform digs or scratches on a surface the approach is slightly modified by first thresholding the surface, i.e. assigning defect related pixels a uniform non-zero value and defect free surface pixels a value of zero, and then by considering the mean value of each column within the areal map instead of the Rq value. As before the standard deviation of the mean values are plotted versus rotational angle. Figure 3 depicts typical polar plots resulting from the presence of multiple uniform features on a surface. The presentation will outline what feature information can be extracted directly from the polar plots and how to determine the number of features on a surface. Limitations of the approach in detecting multiple different features simultaneously will be explained. Opportunities for automation in industrial applications will also be discussed.

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Figure 1. The steps involved in the basic process [2].

Figure 2: Areal maps of different surfaces and their corresponding polar plots [2].

(a) (b)

Figure 3: Polar plots using the modified method when multiple uniform (a) digs, and (b) scratches are present on the surface.

Main References [1] Azimi, F., B. Young, and B. Mullany, Statistical Analysis of Surface Measurements and Images, in American Society for Precision Engineering. 2017: Charlotte, NC, USA [2] Azimi, F., Mullany, B., Geometric surface feature detection using statistical based metrics, submitted to Precision Engineering Jan 2019.

72 Abstract submitted to the www.metprops2019.org conference Conference 069

The influence of edge effect on the wavelet analysis process

D Gogolewski1, W Makieła1 1Kielce University of Technology, Faculty of Mechatronics and Mechanical Engineering, Department of Manufacturing Engineering and Metrology, 25-314 Kielce, Poland

E-mail: [email protected]

Keywords: surface texture, wavelet analysis, edge effect

Abstract Nowadays, the Gaussian filtration is the most widely used for the separation of the surface irregularities. In this analysis, filters with a specific cut- off length are used to determine the form, waviness and roughness of the 2D profile. According to the standard, the measurement should be carried out on evaluation length of more than five sampling length. This is related with the basic problem of filtration of non-periodic profiles, i.e. the determination of the profile at the ends of evaluation length. In order to determine the value of the filtered profile at the particular point, the values of the measured profile in a certain neighborhood of this point is take into account. However, for non- periodic profile, the profile values lying outside the area where the measurement was made are not known. In literature, this problem is called the edge effect. Analyzing the current state of the art, it can be noted that there are many papers related with this problem. Therefore, an important issue is the evaluation of the filtration method taking into account new methods data analysis, especially the method based on application of particular mother wavelet. At the turn of the years, the wavelet transform was increasingly used in the analysis of the surface texture. In the paper, the authors take attempt to assess the edge effect resulting from the analysis using wavelet transform of the 2D profiles. A comparative analysis of the profiles was performed. In this analysis were used profile obtained as a result of filtration over the entire measurement section (taking into account only the profile in the middle section) and profile obtained as a result of filtration carried out only on the middle section of the profile. The main aim of the research was to assess the profile at their ends. However, the research has been extended to analyze the entire 2D profile. The research was carried out taking into account the parameters of the wavelet transformation, i.e. the type of mother wavelet, the level of decomposition and the density of the horizontal sampling. The samples were made of 316L steel. For this purpose, additive technology SLM (Selective Laser Melting) was used. The article presents the research results in which it has been shown that the selected parameters of wavelet transform affect the size of the edge effect of the 2D surface profiles. Figure 1 shows an example of 2D surface profile created as a result of application the mother wavelet db3, at the fifth level of analysis. The primary profile was measured with horizontal sampling density Δx=0,125µm. In addition, Figure 2 shows the difference between coefficient values for two analyzed profile at their ends.

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Figure 1. Surface profile obtained as a result of using mother wavelet db3 at the fifth level of analysis, Δx=0,125µm (red colour represents the profile obtained as a result of filtration the entire measurement section, and blue, dotted line - the profile obtained as a result of filtration only the middle section of the profile)

Figure 2. The difference between coefficient values for two analyzed profile (blue color) a) beginning of the profile b) end of the profile. The line equal 0 is marked with red.

Main References [1] Janecki D. (2012) Edge effect elimination in the recursive implementation of Gaussian filters. Prec. Eng., 36, pp 128– 136 [2] Krystek, M. (1996). Form filtering by splines. Measurement, 18 1, pp 9−15. [3] Blateyron, F. (2014) Good practices for the use of areal filters, Proceedings of 3rd Seminar on surface metrology of the Americas, Albuquerque. [4] Gogolewski, D., Makieła, W. (2018) Application of wavelet transform to determine surface texture constituents. Proceedings of the International Symposium for Production Research 2018, pp 224-231 [5] Jiang X, Scott P and Whitehouse D (2008) Wavelet and their applications for surface metrology CIRP Ann-Manuf Techn, 57 pp 555- 558 [6] Brown C.A., Hansen H.N., Jiang X., Blateyron F., Berglund J., Senin N., Bartkowiak T., Dixon B., Le Goic G., Quinsat Y., Stemp W.J., Thompson M.K., Ungar P.S., Zahouani H. (2018) Multiscale analyses and characterizations of surface topographies, CIRP Ann-Manuf Techn, 67 pp. 839-862

74 Abstract submitted to the www.metprops2019.org conference

SESSION 6

75 Abstract submitted to the www.metprops2019.org conference

Conference 006

Comparison of three multiscale approaches for topography analysis

R Guibert1, S Hanafi1, M Bigerelle1, C A Brown2 1Univ. Polytechnique Hauts-de-France, CNRS UMR 8201 - LAMIH - Laboratoire d’Automatique de Mécanique et d’Informatique Industrielles et Humaines F-59313, Valenciennes, France 2Mechanical Engineering Department, Worcester Polytechnic Institute, Worcester, MA 01609-2280, USA

E-mail: [email protected]

Keywords: surface topography, roughness, multiscale decomposition, polymer, abrasion

A well understanding of physical phenomena and their coupling is essential in the analysis of materials and their manufacturing. Surface topography is then a common tool for such analysis. However, when many phenomena are interacting between each other, isolating each one of them is required to ease the analysis process. Multiscale decomposition is a technique aiming at the separate detection of such phenomena, based on the fact that physical phenomena can be involved at different scales. In this study, three multiscale decompositions are compared: the patchwork method [1] (based on Richardson’s decomposition), the box method [2] and the morphological method using Wolf Pruning-like segmentation [3]. Each decomposition is applied to the analysis of the abrasion of a polymer, namely PEEK, measured with the help of a white light interferometer and a Mirau X50 objective. Each PEEK sample is a polymer disk abraded with various grit papers, from FEPA grade 80 to 4000. Studied surfaces have then different wear stages. In order to increase the multiscale analysis range, stitching was used to obtain 170 large and high precision surfaces. The results highlight crossovers discriminating macro and micro abrasions. Those crossovers are detected with the three multiscale decompositions. However, different crossover values are obtained with each method, as the decompositions aim at detecting the scaling evolution of different elements, respectively the developed surface, the box areas and the motifs in a surface topography. In conclusion, the detection ability of the three multiscale decompositions has been compared. Strengths and weaknesses of each method are highlighted, helping in the selection of the most suited multiscale decomposition for the study of the abrasion of polymers.

76 Abstract submitted to the www.metprops2019.org conference

Figure 1. Three multiscale decompositions of surface topographies: Richardson-based Patchwork, box and morphological methods

750.0 500.0

250.0

75.0 50.0

25.0 Crossover (µm)

7.5 Material / Multiscale Decomposition : 5.0 PEEK / Morphological PEEK / Richardson-Based 2.5 PEEK / Box Counting 20 26 32 38 44 50 56 62 68 74 80 86 92 98 104 110 116 122 128 134 140 146 152 158 164 170 176 182 188 194 200

Grain Mean Diameter (µm) Figure 2. Crossover detection in the abrasion of PEEK using patchwork, box and morphological multiscale decompositions

Main References

[1] C. A. Brown, P. D. Charles, W. A. Johnsen, and S. Chesters, “Fractal analysis of topographic data by the patchwork method,” Wear, vol. 161, no. 1, pp. 61–67, Apr. 1993. [2] C. A. Brown et al., “Multiscale analyses and characterizations of surface topographies,” CIRP Annals, Jul. 2018. [3] A. Van Gorp, M. Bigerelle, and D. Najjar, “Relationship between brightness and roughness of polypropylene abraded surfaces,” Polymer Engineering & Science, vol. 56, no. 1, pp. 103–117, Jan. 2016.

77 Abstract submitted to the www.metprops2019.org conference

Conference 060

Crossing-The-Line Segmentation as a Basis for Roughness Parameter Evaluation

J Seewig1, PJ Scott2, M Eifler1, D Hüser3 1 Technische Universität Kaiserslautern, Germany, Institute for Measurement and Sensor-Technology 2 University of Huddersfield, UK, Centre for Precision Technologies 3 Physikalisch-Technische-Bundesanstalt Braunschweig, Germany, Department 5 Precision Engineering

E-mail: [email protected]

Keywords: surface texture, profile element, topography measurement

Abstract

Profile surface texture parameters are defined in ISO 4287:1997 [1]. The standard includes the well-known amplitude parameters Ra, Rq, Rz and with the mean width of all profile elements Rsm also a method for a lateral characterization based on the segmentation in individual profile elements [1] (see [2,3] for an historical overview). Unfortunately, the current definition of Rsm in ISO 4287:1997 is insufficient for an unambiguous implementation in a high-level programming language. Due to the lack of a program flow chart, results of different measuring instruments and evaluation routines are not comparable.

The profile standard ISO 21920, which is currently under development by TC 213 WG 16, will replace ISO 4287 [1]. The replacement will include a paradigm shift in roughness measurement techniques because almost all parameters will be defined by profile hills and profile dales instead of simple profile ordinates. Thus, the feature-based characterization of rough surfaces is of growing interest, however amongst other prerequisites requires a rigorous definition of the parameter Rsm. We suggest a determination of profile elements based on the so called crossing-the-line segmentation in order to ensure a comparability of feature-based evaluations. The algorithm detects hills and dales with regard to distinct mathematical criteria, applies the vertical threshold, merges adjacent hills and dales and finally determines e.g. the parameter PSm, RSm, WSm based on all profile elements.

The objective of the proposed algorithm is the specification of an unambiguous implementation. In addition to the vertical threshold for the profile element determination [4] other aspects have to be taken into account for the segmentation: First, we describe how end effects can be addressed when the

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profile dales and hills are determined. Additionally, so-called “zero-elements” are introduced. These profile segments can be assigned neither to a profile hill nor dale. As the combination of profile hills and dales to profile elements depends on the direction of the analysis, an averaging of both possible evaluation directions is performed. Figure 1 illustrates an example for the application of the described algorithm. There, the handling of end elements, zero-elements and the directionality of the evaluation are illustrated.

The algorithm leads to an unambiguous parameter evaluation and is simple to implement. Besides a detailed analysis of the described profile features, a program flow chart will be given and as an example the implementation in Python shows the ease to use.

Figure 1. Example for an Xsm / Xc determination with the proposed algorithm. Detected profile elements are indicated with the coloured areas. Depending on the direction of the determination different profile elements are detected.

Main References [1] ISO 4287:1997 (1997) Geometrical Product Specifications (GPS) – Surface texture: Profile method – Terms, definitions and surface texture parameters. [2] Stout, K. (2000): Development of methods for the characterisation of roughness in three dimensions. Rev. repr. London: Penton Press. [3] Blunt L, Jiang X (Eds.) (2003): Advanced techniques for assessment surface topography: Development of a basis for 3D surface texture standards "SURFSTAND". London: Kogan Page Science. [4] Scott P (2006) The case of surface texture parameter Rsm. Measurement Science and Technology 17, 559-564

79 Abstract submitted to the www.metprops2019.org conference

Conference 036

A model of light transmission on abraded glasses

M Bigerelle1, F Robache1, PE Mazeran2 1Univ. Polytechnique Hauts-de-France, CNRS UMR 8201 - LAMIH - Laboratoire d’Automatique de Mécanique et d’Informatique Industrielles et Humaines F-59313, Valenciennes, France 2Sorbonne Universités, Université de Technologie de Compiègne, Laboratoire Roberval, FRE UTC-CNRS 2012, Centre de Recherches de Royallieu, 60203 Compiègne, France.

E-mail: [email protected]

Keywords: surface topography, roughness, light transmission, abrasion, numerical Model.

Context Abrasion on glasses modify the surface topography by creating a roughness with a succession of reliefs, which will amplify diffusing of the light on the surface and then less light passing through the glass. A question arises naturally, is there between the surface topography and the transmission of light on a glass? Are there roughness parameters that strongly correlate to severity of abrasion? To answer to this question we will proposed to create a model to analyse the effect of abrasion on light transmission. It exists numerous methods to analyse transmission/reflexion on surfaces. One can briefly classify methods: Phenomenological ones, facets methods, stochastic ones (like ray tracing) and finally physical models (electromagnetic).

Modelling We will retain an electromagnetic model and enrich it to integrate the absorption aspects of light and then avoiding to create facetted surfaces because they are scale dependent [1]. However, modelling by an electromagnetic model on a real 3D surfaces is too computation times consuming and cannot be applied on real 3D topographical map. In this paper, we statistically proved that a high number of simulation at a microscopic level must be performed to obtain a representative effect at the macroscopic level of light transmission. To do that, all characteristic area will be defined.

Topographical Representative Surface Area The characteristic scales length of a middle level of abrasion on glass seems to lead that the minimum scanning area of one square of 1mm x 1mm millimetre must be performed to integrate all the particularity of surface topography. In our cases, this is the TRAS (Topographical Representative Surface Area) and more precisely, this is the minimal area to model roughness topography. Let note  the whole surface and ’  , and let note P(TRAS) the set of P roughness parameters construct on ’. ’ is a TRAS if and only if E(P(’), with E(X) the mean of X, remains constant whatever ’  . This assumption is compatible with fractal properties of E(P(’) (constant Hölder exponent on ) on but not

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for multi-fractal ones (local Hölder exponent on ). All optical models (deterministic or stochastic ones) is based on the principle the scattering surface area is P(TRAS). Briefly summarized, the surface is perfectly known even in probabilistic formulation. In mathematic formulation, if we notice (TRAS) a mathematical model that returns K physical responses noted K[(TRAS)] (Model constructed on Discretized Topography, MDT models) or K[(E(P(TRAS)))] (Model constructed on Roughness Parameters, MRP models), then K is not stochastic even if  is a stochastic model. In a mathematical sens, this means that VAR(K[(P(TRAS))])=0, where VAR(X) is the variance of X, for MRP models and VAR(K[(TRAS)])=0 for MDT model. Let now analyse the case of MDT model.

Formulation Let notice K*,Km*,Kt* respectively an estimation of error on K, an systemic error of the formulation of a physical model indexed by i, and an error due to the variation caused by roughness parameters estimation with Km(i)*= VAR(K[i(E(P(TRAS)))]) Kt(i)* = VAR(K[i(P(’)]) and Kt*(n,i)→0, for n→ with Kt*(n,i), estimation of Kt(i) construct on n independent (no overlap) surfaces ’ noticed ’(n). Then to the variation due to roughness parameters estimation Km(i,n)*= Kt(i)+Kt*(n,i)+ 2*C(i,n) (1) With C(i,n)=COV(K[i(E(P(TRAS)))], i(P(’)) the covariance errors Model- Surface

th In this formulation, Kt(i) is a i numerical model. More precisely, is considered as a numerical model the physical model itself associated with all numerical parameters (discretization, convergence criteria…). Eq.1 can allows to determine independently - The number of surface to introduce to estimate physical response of the ith model with a fixed confidence interval. - For a fixed number n of surfaces, the error on physical response

But the major interest is to test efficiencies between different models. Eq1 allows us to avoid to create too precise models (and useless time consuming) according to the real information contained in the experimental topographical maps.

This new generic concept is applied to construct a new electromagnetic model of light transmission on rough glass surfaces.

Transmission light model hypothesis To create this model, following assumptions are made i) Homogeneous material, ii) One wavelength, iii) No multi-reflection, iv) 2 D Model, v) Model applied on real surfaces, vi) Normal light on the surface, vii) A constant fraction of the energy is transmitted on the specular spike normal to the surface, viii) No Lambertian source, ix) Approximation on the transmission of the electric field and flux: it is considered that the energy transmitted in the glass is k * lim (E

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(t)), t→0. T angle from normal. Numerically, it is estimated that t <0.1 °. k is a media absorption constant.

Transmission light model hypothesis In application, 17 abraded surfaces are tested. The figure 1 represents the effect of angles of illumination on absorption a fixed abrasion damage. Kt*(n,i) are estimated (bar plot error) on the right for n=200000.

Conclusion This clearly means that uncertainty to model accuracy a physical phenomenon (i.e. representatives descriptions of the local topography used to model physically a phenomena) cannot be dissociated to the measure of the topographical and their “uncertainties” (i.e. robust statistical estimation of the local topography). This aspect of surface metrology is often omitted in simulation and proved that the surface topography community will plays a major role in simulation on rough surfaces.

Main References

[1] C. A. Brown, P. D. Charles, W. A. Johnsen, and S. Chesters, “Fractal analysis of topographic data by the patchwork method,” Wear, vol. 161, no. 1, pp. 61–67, Apr. 1993.

Figure 1. BRDF (Left) obtains for 3 directions of scattering by electromagnetic model (0, 45, 90°) and their transmission energy (right).

82 Abstract submitted to the www.metprops2019.org conference Conference 028

Material & Surface design methodology – the user study framework

M Bergman1, B-G Rosen1,2, L Eriksson2,1, L Lundeholm2 1Halmstad University, Functional Surfaces Research Group, 2Jönköping University, Industrial Design Department

E-mail: [email protected]

Keywords: surface texture, affective engineering, industrial design, Kansei, surface, perception, user study, process control

Abstract: A material and surface selection within the car industry is usually based on a comprehensive study based on sensation and perception, focusing on particular perceived qualities and impressions (emotional functions) through visual and tactile interaction of plastic surfaces. On top of that ‘emotional function’, the ‘technical function’ (such as surface roughness or gloss) for a certain matter in symbiosis will result in a number of material and surface proposals. The range of materials fitting into the window of these requirements varies depending on the industries ability to hit the target specified, however also how properly those targets are defined, especially the ‘emotional functions’. Thus, to be able to get a deeper understanding of how to frame the ‘emotional functions’ and link them to the ‘technical functions’, a number of user studies were made in this project. The user studies were made with two different frameworks however with the same main research target to be able to understand the varieties of them two. The aim of doing so was to be able to find the user study framework that was the most time efficient and providing the most significant data linked to the ‘technical functions’ and process control/traceability, however also finding the framework with the less strains for the participating users in regard to uninterrupted brain activity. The second study generated more significant data in a shorter amount of time; furthermore the result of the main research question (perceived quality) seems to have limited similarities with the first (more time consuming) study. The data was collected and analysed in JMP, by SAS Institute Inc.

83 Abstract submitted to the www.metprops2019.org conference

Figure 1. Picture showing an illustration of the first user study setup for surface evaluation. The user study framework was designed for visual pairwise comparison [xx].

Figure 2. Picture showing an illustration of the second user study setup for surface evaluation. The user study framework was designed for visual and tactile evaluation in different steps [xx]. This is the first step categorizing the surfaces in preference bins, 1=Preferred, 2=Acceptable and 3=Unacceptable.

84 Abstract submitted to the www.metprops2019.org conference

Mean(Quality Marginal Utility) vs. Surface ID Preference Bin Prefered Acceptable 1,5 Unacceptable

1,0

0,5

0,0 Quality Marginal Utility Quality Marginal

-0,5

-1,0

-1,5 HBMIJFKCEGADL Surface ID ordered by Quality Marginal Utility (ascending)

Figure 3. Graph illustrating a sequence from the second surface evaluation, where the surfaces (x- axis) and perceived quality (y-axis) are presented with an overlay feature of preference bins (see legend) [xx].

Main References [1] ISO 9001:2015 (2015) Quality management systems — Requirements. [2] Nagano H, Okamoto A and Yamada Y (2013) Visual and Sensory Properties of Textures that Appeal to Human Touch International J. Affective Engineering 12 3 pp 375-384 [3] Wolfe M J, Kluender R K, Levi M D, Bartoshuk M L, Herz S R, Klatzky R, Lederman J S and Merfeld M D (2012) Sensation & Perception 3rd edition. Sinauer Associates, Inc. Library of Congress Cataloging-in-Publication Data. [4] Pointer M R (2003) New Directions – Soft Metrology requirements for Support from Mathematics, Statistics and Software: recommendations for the Software Support for Metrology programme 2004-2007 NPL Report CMSC 20/03 (Teddington: National Physical Laboratory) (ISSN 1471-0005) [5] Osgood C E, George J S and Tannenbaum P H (1943) The Measurement of Meaning (Urbana IL USA: University of Illinois Press)

85 Abstract submitted to the www.metprops2019.org conference

SESSION 7

86 Abstract submitted to the www.metprops2019.org conference

Conference 008

Improving Accuracy of Fitting of Freeform Surfaces

M Poniatowska1, D Groch1 1Bialystok University of Technology, Faculty of Mechanical Engineering

E-mail: [email protected]

Keywords: freeform surfaces, accuracy of fitting, CAD model of the gap, machining error correction, milling

Abstract: An important problem in the milling of injection molds is the achievement of an adequate accuracy of the fitting of the closing surfaces, which are often free in form. Deviations of surfaces processed from the nominal shape cause a leak in the joint and, as a result, a plastic leak. In the literature on multi- axis milling of the free-form surfaces, much attention is paid to improving the accuracy of the surfaces treated. One approach is to analyze surface deviations after machining and to improve accuracy by modifying the machining program by introducing compensating corrections. Measurements of the freeform surfaces are most often carried out on numerically controlled coordinate measuring machines, equipped with contact measuring heads. The result of the measurement is a set of points with a specific distribution on the surface. For each measuring point a local deviation is determined, i.e. the distance of the measurement point from the CAD model in the normal direction. Then the nominal CAD model is modified by adding local deviations with the opposite sign. The article proposes a new methodology for the correction of machining errors of the cooperating two freeform surfaces. It consists in improving the accuracy of their fitting by introducing compensating corrections to the machining program of one of the surfaces. The basis of the methodology is the CAD model of the gap between surfaces designed on the basis of coordinate measurement data. This model is applied to determine compensating corrections in the second processing step. The advantage of this methodology in relation to the correction of errors of both surfaces is increasing the efficiency of the processing, because in the second stage only one of the surfaces is machined. Simulation and experimental tests confirmed an increase in the accuracy of surface fit by 80%.

87 Abstract submitted to the www.metprops2019.org conference

a) b)

Figure 1. Map of the width of the CAD model of the gap: a) before correction, b) after correction.

Table 1. Results of fitting accuracy tests (mm)

The gap model width, mm Before After

correction correction mean 0,0162 0,0035 maximum 0,0000 0,0000 minimum 0,0322 0,0062

Main References [1] Jia Z, Ma J, Song D, Wang F, Liu W (2018) A review of contouring-error reduction method in multi-axis CNC machining International Journal of Machine Tools and Manuf. 125 pp 34-54 [3] Sladek J A (2016) Coordinate Metrology: Accuracy of Systems and Measurements (Springer, Berlin Heidelberg) [4] Poniatowska M (2015) Free-form surface machining error compensation applying 3D CAD machining pattern model Comput.-Aided Des. 62 pp 227-235 [5] Upton G J G, Fingleton B (1985) Spatial Data Analysis by Example Vol. 1 (John Wiley & Sons, New York) [6] Piegl L, Tiller W (1997) The NURBS book, (2nd ed., Springer-Verlag, New York)

88 Abstract submitted to the www.metprops2019.org conference Conference 070

Vertical Focus Probing and smooth surface measurement by an optical surface measuring instrument based on Focus- Variation

K Zangl 1, R Danzl 1, F Helmli 1, M Prantl 1 1Alicona Imaging GmbH

E-mail: [email protected]

Keywords: Focus-Variation, Vertical Focus Probing, µCMM, smooth surfaces, micro hole, vertical wall, measurement noise

Abstract (Intro-Background) Focus-Variation is known to be an optical measurement method which allows high resolution form and roughness measurements of surface topographies which are not completely smooth (Ra  9nm with c 2µm) and the measurement of steep slopes up to 87° [1, 2]. The independence of illumination sources leads to robustness in case of strong reflective surfaces with complex micro geometries. Nevertheless, the requirements of manufacturers regarding measurement of samples, independent of their surface characteristics and geometry, increases. Especially, the measurement of completely smooth surfaces as well as the measurement of micro holes and vertical walls with a slope angle of  90° is essential for many applications. These requirements give rise to further development of existing measurement methods to increase the range of measureable samples. (Materials and Methods) In this paper, the extension of the Focus-Variation technology in two different directions is presented. On the one hand, Focus-Variation with Smart Flash 2.0 allows the measurement of smooth surfaces using modulated illumination. Its performance is demonstrated on the basis of mirror measurements including a measurement noise evaluation by the subtraction method according to ISO 25178-700 [3, 4]. On the other hand, Vertical Focus Probing is presented, which is based on exploiting information of the partial illumination cone as shown in Figure 1, where the light is reflected by the wall. For the measurements in this paper, an Alicona µCMM [5] is used for the evaluation. The µCMM is a highly accurate, purely optical micro coordinate machine with a sensor based on the Focus-Variation technology which can be equipped by several lenses. (Results) In this paper, examples of measurements of completely smooth samples are presented (see Figure 2). The evaluation of measurement noise according to ISO 25178-700 results in a measurement noise of NM=0.69nm for the 50x lens and NM =3.67nm for the 10x objective. Additionally, results of vertical wall measurements using Vertical Focus Probing are shown. Using this measurement principle, micro holes with a diameter to depth ratio of 1:10 and a diameter of about 500µm can be measured using a 10x lens. Moreover, a comparison of the surface characteristics between a Vertical Focus Probing measurement and a Focus-Variation measurement of the 90° rotated wall is shown in Figure 1 where similarity of small surface structure

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features demonstrates the quality of Vertical Focus Probing. (Conclusions) The results of the paper show the strength and the high potential of the extensions of Focus-Variation with respect to Smart Flash 2.0 and Vertical Focus Probing. With these further developments, two main limitations of the Focus-Variation technology are lifted – the measurements of surface topographies with an Ra less than 9nm and the measurement of steep slopes with more than 87° are possible. Typical applications of tactile coordinate measurement instruments are GD&T applications as e.g. the distance measurement of opposite sides of a sample (see Figure 3) where the probes lateral touch the sample at the side walls. Vertical Focus Probing closes the gap between tactile and optical measurement instrument and allows such measurements by an optical measurement system based on Focus-Variation for the first time. An example is shown in Figure 4, where a cutting tool is measured including the top surface and several side wall patches measured from the same scan direction perpendicular to the top surface. (Future activities) Current activities include a complete measurement noise evaluation including average calculation of several subtractions for all lenses (5x, 10x, 20x, 50x, and 100x). Further developments of Vertical Focus Probing focus on the higher robustness of the method regarding complex geometries and the speed-up of the measurement.

300-600 words here (figure-, table- and reference words not included)

Figures, tables and main references added on separate pages below

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Figure 1. Left: Vertical Focus Probing measurement of a vertical wall with a slope angle of 90° with respect to the scan direction. Right: Measurement of the same wall rotated by 90° without a slope angle with respect to the scan direction. The measurements show the same overall surface characteristics as well as very similar small surface structure features.

Figure 2. Left: Single field measurement of a mirror using the µCMM and Focus-Variation with Smart Flash 2.0. Right: Areal Surface Texture of the difference dataset of two subsequent measurements of a mirror. The measurement noise of 0.69 nm is calculated on the basis of the Sq value according to ISO 25178-700 [3].

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Figure 3. Measurement principle for distance measurements by tactile measurement instruments and optical measurement instruments using Vertical Focus Probing.

Figure 4. Left: Vertical Focus Probing measurement of a cutting insert, where the top surface and the side wall patches are measured from the same scanning direction, perpendicular to the top surface. Right: distance measurement between two side wall patches.

Main References [1] ISO 25178-606:2015 (2015) Geometrical product specification (GPS) -- Surface texture: Areal - - Part 606: Nominal characteristics of non-contact (focus variation) instruments [2] Danzl R, Helmli F and Scherer S (2011) Focus variation – A robust technology for high resolution optical 3D surface metrology, Journal of Mechanical Engineering 57 pp 245-56 [3] ISO 25178-700:2018 (2018) Geometrical product specifications (GPS) -- Surface texture: Areal -- Part 700: Calibration, adjustment and verification of areal topography measuring instruments (draft) [4] Giusca C L,Claverley J D, Sun W, Leach R K, Helmli F and Chavigner M P J (2014) Practical estimation of measurement noise and flatness deviation on focus variation microscopes, CIRP Annals 63 1 pp 545-548 [5] Zangl K, Danzl R, Helmli F and Prantl M (2018) Highly accurate optical µCMM for measurement of micro holes, Procedia CIRP 75 pp 397-402

92 Abstract submitted to the www.metprops2019.org conference

Conference 037

Multiscale analysis of the morphological signature of roping

J. Marteau1, J.-D. Mithieux2, R. Deltombe3, M. Bigerelle3 1Sorbonne Universités, Université de Technologie de Compiègne, Laboratoire Roberval, FRE UTC-CNRS 2012, Compiègne, France. 2APERAM, France. 3Laboratoire d’Automatique, de Mécanique et d’Informatique industrielles et Humaines LAMIH UMR-CNRS 8201, Université Polytechnique des Hauts de France, Valenciennes, France.

E-mail: [email protected]

Keywords: surface texture, roping, ridging, multiscale analysis.

Abstract Tensile deformations of rolled metal sheets can induce undesirable surface roughening known as ‘orange peel’, ‘roping’ or ‘ridging’. This phenomenon was observed in aluminum [1,2] as well as stainless steel [3,4]. Even if the origin of roping is still discussed, researchers tend to agree that roping is the result of inhomogeneous plastic flow due to different plastic anisotropy of grains [5]. As ferritic stainless steels are sometimes partly selected by attractive visual aspect, the deterioration of the visual aspect by roping can be very detrimental. Experts visually classify steel samples into five levels of roping amplitude. This study aims at identifying the morphological signature of roping using a multiscale analysis of roughness. Ten sheets showing different levels of roping (Level 1 to Level 5) were analyzed. Steel sheets showing roping levels equal to 1 and 2 can be used whereas steel sheets showing roping levels from 3 to 5 cannot be used as such. A three-dimensional non-contact optical profilometer was used to perform topography measurements at three different scales: ‘large’ scale measurements (84385x 17691 µm²), ‘medium’ scale measurements (1188x891 µm²) and small scale measurements (349x261 µm²). The multiscale analysis was performed using different cut-off filters (high pass, low pass and band-pass filters) and cut-off lengths on the large scale measurements and medium scale measurements. As expected, the computations of the arithmetic mean deviation Sa of the surface roughness for the medium scale measurements (at full scale) did not enable us to identify a relationship between the level of roping identified by the experts and the morphology of the topography, as shown in Figure 1. No relationships were identified with the computations of Sa at different scales, either. Then, fifty different roughness parameters were computed at different scales to try to identify a relationship between roping level and a given roughness parameter. The texture aspect ratio Str computed using low-pass filter with a cut-off length of 32 µm was identified as the best combination of roughness parameter and scale. As shown in Figure 2, the Str computed at this scale enabled us to distinguish the acceptable sheets from the non-acceptable ones. These first results showed that roughness amplitude is similar whatever

93 Abstract submitted to the www.metprops2019.org conference

the identified level of roping. The visual aspect of roping is linked to surface anisotropy, which reflects the material anisotropy. Examinations of the large measurements confirmed these results. Finally, Wolf-Pruning segmentation was performed on the small scale measurements and enabled us to identify different sizes and shapes of motifs. These motifs seem to correspond to the material grains. Based on these first results, roughness measurements were performed before the tensile tests (and thus roping appearance) to propose a methodology of identification of roping level without the use of tensile tests followed by visual identifications of the roping levels.

Figure 1. Arithmetic mean deviation Sa as a function of the sheet aspect i.e. the level of roping identified by the expert.

94 Abstract submitted to the www.metprops2019.org conference

Figure 2. Texture aspect ratio Str as a function of the sheet aspect i.e. the level of roping identified by the expert, computed using a low-pass filter with a cut-off length of 32 µm.

Main References [1] Baczynski GJ, Guzzo R, Ball MD, Lloyd DJ. Development of roping in an aluminum automotive alloy AA6111. Acta Mater 2000;48:3361–76. doi:http://dx.doi.org/10.1016/S1359- 6454(00)00141-5. [2] Bennett TA, Petrov RH, Kestens LAI. Texture-induced surface roping in an automotive aluminium sheet. Scr Mater 2009;61:733–6. doi:http://dx.doi.org/10.1016/j.scriptamat.2009.06.016. [3] Huh MY, Engler O. Effect of intermediate annealing on texture, formability and ridging of 17%Cr ferritic stainless steel sheet. Mater Sci Eng A 2001;308:74–87. doi:http://dx.doi.org/10.1016/S0921-5093(00)01995-X. [4] Zhang C, Liu Z, Wang G. Effects of hot rolled shear bands on formability and surface ridging of an ultra purified 21%Cr ferritic stainless steel. J Mater Process Technol 2011;211:1051–9. doi:http://dx.doi.org/10.1016/j.jmatprotec.2011.01.005. [5] Sztwiertnia K, Pospiech JG. Orientation topography and ridging phenomenon in ferritic stainless steel sheets. Arch Metall 1999;44:157–65.

95 Abstract submitted to the www.metprops2019.org conference

Conference 050

Performance of Pin and Roller Surfaces of Truck's Valvetrain under Contaminated Lubricating Conditions

S. John1, P.-J. Lööf1, Z. Dimkovski1, Jonas Lundmark3, J. Mohlin2, Lars Hammerström4 1 School of Business, Engineering and Science, Halmstad University, PO Box 823, SE-301 18 Halmstad, Sweden 2 Applied Nano Surfaces AB, 12 Knivstagatan, 753 23 Uppsala, Sweden 3 Gnutti Carlo Sweden AB, 60 Aröds Industriväg, 422 43 Gothenburg, Sweden 4Scania CV AB, Materials Technology, SE-151 87 Södertälje, Sweden

E-mail: [email protected]

Keywords: surface texture, Friction, Wear, Topography, Valve train,

Abstract In order to minimize the fuel consumption in internal combustion engines, the frictional losses must be minimized between the moving parts such as the sliding bearings. In this study, the sliding friction between the pin and roller with different type of lubricated oil in a heavy-duty truck engine’s valvetrain has been investigated. Two combinations of production components with different surface treatment were used: (i) bronze pin with steel roller, (ii) steel pin with WS2 coating inside the roller. The friction test was carried out with engine oil (i) SAE 20 clean oil, (ii) SAE 30 contaminated oil with different test sequence of to find out the best sample along with identify the impact of contaminated oil additives on the surfaces. Another aim of this paper is to properly quantify the topographical variations of the pin/roller surfaces and asses the appropriateness of the measuring technique before and after the tribological tests primarily performed for friction reduction. In-house test rig was used, enabling controlled conditions close to the real engine. A test carried out with different type of serve duty test oil. Surface topography of pins and rollers was measured with a mechanical stylus instrument and interferometer. A significant number of abrasive particles was found to be present in the pin/roller assembly. Results say that presence of abrasive particle and larger number of tests increase the wear and friction. In addition, that reference (bronze pins/standard rollers) samples had higher friction and wear than the new (steel pins/WS2 coated rollers) samples in all the tests. Improvement of test procedure for pin and roller to show behaviour under realistic lubrication conditions with oil containing abrasive particles to evaluate the performance of the new coating WS2 compared to bronze. It is possible to replace bronze with steel using WS2 coating. The contaminated oil shows higher friction and wear compared to the clean oil for both sample types (i) and (ii). Increasing running time with the contaminated oil increases the friction and wear. The 3D parameters: Vmp and Spk after the test type 1 (clean+ contaminated oil) showed a clear increase for the reference samples while Vvv & Svk for the new (WS2-rollers) samples.

96 Abstract submitted to the www.metprops2019.org conference

Figure 1. The surface topography of friction after Triboconditioning of the WS2 and bronze surfaces

Main References [1] Holmberg K, Andersson P and Erdemir A 2012 Tribology International 47 221 [2] Miyoshi, K., Wheeler, D. R., 1996, “Surface Chemistry, Friction, and Wear Properties of Untreated and Laser-Annealed Surfaces of Pulsed-Laser-Deposited WS2 Coatings,” NASA Technical Memorandum 107342. [3] Zhmud B 2011 Tribology and Lubrication Technology 67 42 [4] Zhmud B 2012 Proc. STLE Annual Meeting (St. Louis, USA, May 7-10) [5] Dimkovski Z., Guilbert F Lundmark J Mohlin J Rosén B.-G., (2015), Optimization of the Triboconditioning Process on External Cylindrical Surfaces, in Proceedings of the 15th International Conference of Metrology and Properties of Engineering Surfaces, March 2-5, 2015, Charlotte, USA. [6] Shobin John, Zoel El-Ghoul, Zlate Dimkovski, Pär-Johan Lööf, Jonas Lundmark (2018)Friction between pin and roller of a truck's valvetrain, Accepted Manuscript online 14 January 2019 • © 2018 IOP Publishing Ltd.

97 Abstract submitted to the www.metprops2019.org conference

SESSION 8

98 Abstract submitted to the www.metprops2019.org conference Conference 051

Influence of different post-processing methods on surface topography of fused deposition modelling samples

Amogh Vedantha Krishna1, Vijeth V Reddy1, Olena Flys2,1, Gunnar Nilsson3, Henrik Barth4 and B-G Rosen1 1Halmstad University, Functional Surfaces Research Group, Halmstad, Sweden. 2Research Institutes of Sweden (RISE), Borås, Sweden. 3TylöHelo AB, Halmstad, Sweden. 4Halmstad University, Center for Innovation, Entrepreneurship and Learning research, Halmstad, Sweden.

E-mail: [email protected]

Keywords: Additive manufacturing, Fused deposition modelling, Acetone vapour deposition, Shot-blasting, Laser engraving, Surface metrology and characterization, ANOVA, Power spectral density, Areal surface texture parameters, Stripe projection technique.

Abstract: Additive Manufacturing (AM) is gaining prominence due its huge advantage in fabricating complex shapes without any geometrical limitations. The most widely used AM technique is Fused Deposition Modelling (FDM). FDM is an extrusion based AM focused mainly on producing functional prototypes due to its incompetence in producing high quality products which limits the scope of its application in industries [1]. A lot of research has been conducted to identify the optimum print settings to get good quality printed parts, however, it is still necessary to achieve higher precision and quality when it comes to industrial applications. Therefore, post processing helps in achieving the finish that is obtained by conventional manufacturing. This paper focuses on enhancing the surface quality of FDM parts by subjecting it to Acetone vapour deposition (AVD) smoothening [2,3], Shot-blasting and Laser engraving [4] post processing methods. A comparative study is presented, where surface produced by different post processing methods are compared to the reference injection moulding components. The influence of various post-processing parameters on surface topography is captured in this context and most importantly this paper explores different methods for effective characterization of FDM surfaces [5]. Finally, the results are validated by post-processing a real industrial (TylöHelo AB) product. Investigations were carried out on truncheon artefact printed using Acrylonitrile Butadiene Styrene (ABS) material. The material ABS was chosen for the study as it is receptive to the acetone vapours and prolonged exposure of ABS parts can result in a substantial removal of material [4]. This makes ABS an ideal option for performing all the various post-processing methods mentioned in this text. Figure 1 lists various parameters involved in the respective post-processing techniques which influence the surface appearance. Design of experiments were formulated using taguchi’s orthogonal matrix and the experiments were carried out. The surface measurements were taken before and after post processing and compared to the reference injection moulding (see figure 2), using a stripe projection optical microscope. The initial results have suggested that shot blasting and AVD process has surface roughness close to the reference (see figure 2). However, shot-blasting inflicts damages to the components if not properly handled (see figure 3) and AVD surfaces appears to be glossy and over exposure to acetone leads to the deterioration in the dimensional accuracy of the printed part (see

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figure 4). Laser engraving process alters the surface roughness by melting the top layer of the plastic by burning which leads to decolouration of the product (see figure 5). It can be seen from the figure 2 that laser engraved surfaces have roughness close to the 3D printed surfaces, although the raster pattern has been removed. Once the optimum settings for each post processing is established, an actual TylöHelo component is printed and subjected to various post-processing and the quality is assessed by performing the spectral analysis. Further research is required to establish which post processing is the best for finishing the FDM parts.

Figure 1. List of parameters of the respective post processing methods that affect the surface appearance.

Figure 2. 3D topography view of 0° surfaces: (a) Acetone vapour smoothened (b) Shot-blasted (c) Laser engraved (d) 3D printed (e) Injection moulded

Figure 3. Damages inflicted to Figure 4. TylöHelo AB Figure 5. Region depicting the parts while shot blasting component before and after AVD the decolouration due to smoothening. burning of plastic layer while laser engraving.

100 Abstract submitted to the www.metprops2019.org conference

Main References [1] V. Reddy, O. Flys, A. Chaparala, C. Berrimi, A. V and B. Rosen, "Study on surface texture of Fused Deposition Modeling", 2018. [2] A. Lalehpour, C. Janeteas and A. Barari, "Surface roughness of FDM parts after post- processing with acetone vapor bath smoothing process", The International Journal of Advanced Manufacturing Technology, vol. 95, no. 1-4, pp. 1505-1520, 2017. [3] L. Galantucci, F. Lavecchia and G. Percoco, "Experimental study aiming to enhance the surface finish of fused deposition modeled parts", CIRP Annals, vol. 58, no. 1, pp. 189-192, 2009. [4] M. Taufik and P. Jain, "Laser assisted finishing process for improved surface finish of fused deposition modelled parts", Journal of Manufacturing Processes, vol. 30, pp. 161-177, 2017. [5] R. Leach, Characterisation of Areal Surface Texture. Heidelberg: Springer, 2013.

101 Abstract submitted to the www.metprops2019.org conference Conference 065

Feature-based characterisation of Ti6Al4V electron beam powder bed fusion surfaces fabricated at different orientations

Lewis Newton1, Nicola Senin1,2, Bethan Smith3 and Richard Leach1 1Manufacturing Metrology Team, Faculty of Engineering, University of Nottingham, UK 2Department of Engineering, University of Perugia, Italy 3Manufacturing Technology Centre, Coventry, UK

E-mail: [email protected]

Keywords: surface texture, additive manufacturing, electron beam powder bed fusion, feature based characterization

Abstract The study of how surface topography is affected by build orientation is important for understanding the capability of metal additive manufacturing (AM) processes, such as those based on powder bed fusion. Due to the layer- based nature of the process, surfaces built at varying orientations will be differently affected by a wide array of process-induced topographic modifications, including the staircase effect, and the presence of protruded formations (spatter, un-melted or partially melted particles) in some cases significantly occluding the underlying topography. All such process-induced topographic modifications can significantly influence the choices for surface post-processing. Most research investigating surface texture in metal AM has focused on laser powder bed fusion (LPBF) [1–6].Whilst electron beam powder bed fusion (EBPBF) is somewhat similar [7], it features some rather significant differences in the surfaces it produces [4,5,8]. To assess the topography of AM surfaces as a function of orientation, most researchers [1–6,8] have investigated surface texture parameters (profile - ISO 4287 [9] and areal - ISO 25178-2 [10]). In parallel to studying surfaces as a function of orientation, recent work on metal AM has investigated ways to describe the complex topography of additive surfaces via approaches alternative to texture parameters, focusing on the characterisation of topographic formations that populate the typical metal additive surface (weld tracks, spatter formations, particles) [11–13]. These approaches can be collectively referred to as feature-based characterisation. In this work, the topography of EBPBF surfaces as a function of orientation was investigated using a combined approach including both texture parameters and feature-based characterisation. A Ti6Al4V test part (125 × 125 × 25) mm was manufactured using EBPBF with an Arcam A2XX and designed to possess 36 sides to produce surfaces with orientations varying in 10° increments (0°, 10°, 20°, etc.) (Figure 1a). The surfaces were left in their as-built state, except for minimal post-processing, which consisted of grit blasting, typically applied to remove the sintered cake within the EBPBF process. All support structures were removed. The custom characterisation approach featured multiple steps, beginning with the automated identification and separation of all the protruding formations (spatter, partially melted and un-melted particles), such as those

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highlighted in Figure 1b. The formations were separately characterised for quantity, occupied area, distribution, etc. In parallel, the underlying topography, devoid of protruded formations, was characterised using conventional texture parameters. All the computations were performed on replicate measurements for each surface, so that confidence intervals could be used to assess the statistical validity of quantitative differences of results obtained for different surface orientations. The results confirm the correlation between EBPBF surface topography devoid of particles and surface orientation (as expected from the literature [11,12]), but also for the first time provide quantification of the properties of spatter and particles as a function of surface orientation. Future work is to investigate how the same combined approach can be applied to quantify the effects of surface post-processing, both on spatter and particles, and on the substrate.

(a) (b) Figure 1: (a) EBPBF ‘Bracelet’ test part held on rotational stage on a focus variation microscope; (b) reconstructed topographies of measured surface at two differing build orientations with spatter formations identified and highlighted (in colour) from underlying surface (in grey)

References [1] Grimm T, Wiora G and Witt G (2015) Characterization of typical surface effects in additive manufacturing with confocal microscopy Surf. Topogr. Metrol. Prop. 3 014001 [2] Strano G, Hao L, Everson R M and Evans K E (2013) Surface roughness analysis, modelling and prediction in selective laser melting J. Mater. Process. Technol. 213 589–97 [3] Fox J C, Moylan S P and Lane B M (2016) Effect of process parameters on the surface roughness of overhanging structures in laser powder bed fusion additive manufacturing Proc. CIRP 45 131–4

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[4] Triantaphyllou A, Giusca C L, Macaulay G D, Roerig F, Hoebel M, Leach R K, Tomita B and Milne K A (2015) Surface texture measurement for additive manufacturing Surf. Topogr. Metrol. Prop. 3 024002 [5] Weißmann V, Drescher P, Bader R, Seitz H, Hansmann H and Laufer N (2017) Comparison of single Ti6Al4V struts made using selective laser melting and electron beam melting subject to part orientation Metals (Basel). 7 91 [6] Boschetto A, Bottini L and Veniali F (2017) Roughness modelling of AlSi10Mg parts fabricated by selective laser melting J. Mater. Process. Technol. 241 154–63 [7] Körner C (2016) Additive manufacturing of metallic components by selective electron beam melting — a review Int. Mater. Rev. 61 361–77 [8] Sidambe A T (2017) Three-dimensional surface topography characterization of the electron beam melted Ti6Al4V Met. Powder Rep. 72 200–5 [9] ISO 4287:2009 (2009) Geometrical product specification (GPS) - Surface texture: Profile method - Terms, definitions and surface texture parameters [10] ISO 25178-2:2012 (2012) Geometrical product specifications (GPS) - Surface texture: Areal - Part 2: Terms, definitions and surface texture parameters [11] Krishna A V, Flys O, Reddy V V, Leicht A, Hammar L and Rosen B (2018) Potential approach towards effective topography characterization of 316L stainless steel components produced by selective laser melting process Proc.18th Int. euspen Conf., Venice, Italy, June [12] Lou S, Jiang X, Sun W, Zeng W, Pagani L and Scott P J (2018) Characterisation methods for powder bed fusion processed surface topography Precis. Eng. (In Press, Accepted Manuscript) [13] Senin N, Thompson A and Leach R K (2018) Feature-based characterisation of signature topography in laser powder bed fusion of metals Meas. Sci. Technol. 29 045009

104 Abstract submitted to the www.metprops2019.org conference Conference 066

Mathematical reference standards for validating software for calculating surface texture parameters

Luke Todhunter1, Richard Leach1, Simon Lawes1, François Blateyron2 and Peter Harris3 1Manufacturing Metrology Team, University of Nottingham, NG8 1BB, UK 2Digital Surf, Besançon, France 3National Physical Laboratory, Teddington, TW11 0LW, UK

E-mail: [email protected]

Keywords: surface texture, reference software, areal parameters

Abstract (Intro) Surface texture parameters are widely used in the precision engineering and manufacturing industries for the characterisation of surfaces, and to enable meaningful comparison between surfaces and their functional properties [1]. Software packages used to calculate surface texture parameters require validation to ensure obtained values are in line with standardised parameter definitions. The current state of the art for validating software used for surface texture parameter calculation involves comparing the parameter values obtained by the software under test with the values obtained by a reference software package developed by a National Measurement Institute [2,3]. Previous work has shown that the algorithms implemented by such reference software packages can depend on how the standardised parameter definitions are interpreted, and consequently such packages can produce different results [4]. It follows that third-party software cannot be validated in a truly traceable manner using such an approach. (Methodology) A new method for the validation of areal surface texture parameter software is introduced that utilises a mathematical approach to provide traceable reference datasets and corresponding parameter values. Surfaces, or their related properties, are defined algebraically using a range of mathematical functions. The mathematically- defined surface can then be evaluated using a series of operations to obtain traceable, mathematical values for surface texture parameters. The derived mathematical values can then be used as traceable reference values against which third-party software values can be compared. (Case study) Functional surface texture parameters are derived from a series of five mathematically-defined material ratio curves as a showcase for the new validation method. The material ratio curves are numerically evaluated to generate corresponding discrete surface datasets for use with third-party software. The software obtained parameter values are compared with the traceable mathematical parameter values, enabling an assessment of the performance of the software. Differences between the software-obtained parameter values and mathematical values are highlighted, as shown in figure 1. (Dataset verification) An assessment of the difference between using a continuous mathematical surface or a discrete dataset is performed. A series of datasets with different numbers of points are generated and input into the parameter calculation software to assess the effect of

105 Abstract submitted to the www.metprops2019.org conference

discretisation on the calculated functional parameter values. (Conclusion) The approach described offers a reliable way to assess the performance of surface texture parameter calculation software that is not dependent on a specific interpretation of standard parameter definition. The approach improves upon the current state of the art, comparing third-party software to reference software, by removing the dependence on specific algorithms and implementations, and moving toward a fully traceable method. The results given show working examples of mathematically-obtained parameter values, and the ways in which they can be compared to software obtained values. Future work aims to expand the range of surface texture parameters covered using this approach, and develop performance metrics for a meaningful quantitative assessment of surface texture parameter software.

Figure 1. Comparison of functional parameter values obtained by three third-party software packages. The values have ben normalised to the mathematical parameter values.

Main References [1] Todhunter L D, Leach R K and Lawes S D A (2017) Industrial survey of ISO surface texture parameters CIRP J. Manufac. Sci. Technol. 19 84-92 [2] Harris P M, Smith I M, Leach R K, Giusca C, Jiang X and Scott P (2012) Software measurement standards for areal surface texture parameters: part 1—algorithms Meas. Sci. Technol. 23 105008 [3] Smith I M, Harris P M, Todhunter L D, Giusca C, Jiang X, Scott P and Leach R K (2017) Algorithms and software for areal surface texture function parameters Meas. Sci. Technol. 28 105108 [4] Todhunter L D, Leach R K, Lawes S D A and Blateyron F (2017) An analysis of type F2 software measurement standards for profile surface texture parameters Meas. Sci. Technol. 28 065017

106 Abstract submitted to the www.metprops2019.org conference

Conference 068

The Use of Areal Surface Texture Parameters in Characterization of Worn Surfaces

P Pawlus1, A Dzierwa1 1Rzeszow University of Technology, Faculty of Mechanical Engineering and Aeronautics

E-mail: [email protected]

Keywords: surface texture, wear, parameters

Abstract: Characterization of surface evolution during operating is a substantial topic. Machined surface texture changed during a low wear process, when wear is within a limit of an original surface topography. Change of a surface texture during wear can be characterized by surface topography measurement. In this case initial surface topography often affects wear levels. Especially the analysis of material ratio curve can give information about wear progress. Surface topography measurement is helpful for determining local wear values [1, 2]. Surface texture can also be used for determination of types of wear. The aim of this work was to relate kinds of wear with values of areal (3D) surface texture parameters and functions. Many surface topographies after operating wear were measured using a white light interferometer Talysurf CCI Lite. There were surfaces of elements from IC engine like piston skirt, cylinder liner and piston pin. Surface topographies after tests using various tribological testers after reciprocating (including fretting) and unidirectional motions with and without lubrication were also studied. The measured area of 3.3 x 3.3 mm2 contained 1024 x 1024 points. After measurements, form was eliminated using polynomials. Digital filtration was not used. Spikes were removed using surface truncation. It was found that worn surfaces were typically of random natures. Surfaces after abrasion are one-directional anisotropic textures. Surfaces after mild wear (oxidation sometimes connected with abrasion) are smooth textures, of the Sq parameter smaller than 0.2 µm. They are directional surfaces of the Str parameter higher compared to surfaces after pure abrasion (0.2 - 0.4). Adhesive junctions resulted in creating additional peaks and an increase in a surface roughness height. Height of surfaces after catastrophic wear by seizure is big. Their characteristic feature is a small density of peaks and a small number of motifs. During a low wear surface directionality changed, with creation of a new direction. In general, the following parameter are helpful for obtaining information about the type and the progress of wear: Sq, Ssk, Sku, Spd, Str and Sal. The material ratio is useful for determining surface evolution during wear. The analysis of surface motifs gives information about surface uniformity, while directionality analysis study about main surface directions. Figure 1 presents contour plots of selected measured worn surfaces.

107 Abstract submitted to the www.metprops2019.org conference

a b c µm µm 0 1 2 3 mm µm 0 1 2 3 mm 8 120 0 0 1 2 3 mm 0 7 0 4 0.5 100 0.5 6 0.5 1 1 3 5 1 80 1.5 1.5 4 1.5 2 2 60 2 3 2 2.5 40 2.5 1 2 2.5 3 3 1 3 20 0 0 NM mm mm 0 mm

Figure 1. Contour plots of worn surfaces: disc after abrasion (a), piston skirt after seizure (b) , and cylinder after a low wear (c).

Main References [1] Balcon M, Marinello F, Carmignato S, and Savio E (2011) Wear analysis through surface relocation. Proceedings of 13th International Met & Props Conference, Twickenham Stadium UK pp 316-319 [2] Pawlus P, Dzierwa A (2018) Wear analysis of discs and balls on a micro-scale, Tehnički vjesnik 25 (Suppl. 2) pp 299-305

108 Abstract submitted to the www.metprops2019.org conference

SESSION 9

109 Abstract submitted to the www.metprops2019.org conference Conference 055

Coherent Wave Scattering Technology for Decision Making on Polishing Steps

S Rebeggiani1, L Bååth1,2, B-G Rosen1, Z Dimkovski1 1Halmstad University, The Functional Surfaces Research Group, Sweden 2Qisab – QSO Interferometer Systems AB, Halmstad, Sweden

E-mail: [email protected]

Keywords: surface characterisation, abrasive polishing, metrology

Abstract In-line metrology is increasingly entering into production lines for reducing scrape rates, saving natural resources and achieving more sustainable society. One such a fast and robust in-line technology attracting more and more attention to the automated quality control is the Coherent Wave Scattering- CWS technology. However, there is reluctance for using this technology for products/components having polished surfaces due to the limited insights into the correlations of the parameters derived from the CWS measurements with the surface quality. In order to overcome this, a number of Coherence Scanning Interferometry-CSI measurements are performed and compared with the CWS measurements capturing the whole surface of the sample (see Figure 1 and 2). The used CWS instrument [1] has a vertical resolution of Sq=10-350 nm and a spatial sampling of 2x2 µm while the used CSI [2] has a vertical resolution of Sq=0.1 nm, a spatial sampling of 0.65x0.55 µm and 1.1x1.3 µm (20x and 10x objectives respectively). Robot polishing with two different process parameters in two steps was applied on a metallic sample (Figure 1 left). The major difference of the process parameters was the tilt angle of the polishing tool, being 15° and 20°. Beside the standard areal parameters evaluated from the CSI measurements, a detailed description of the grooves generated by the abrasive polishing is obtained by using traceology [3-4]. The traceology utilizes Hough transform in Matlab [5], while the standard parameters were calculated in the MountainsMap software [6]. The traceology parameters (groove width/height, orientation, crossover) are primarily used to understand the action of the abrasives related to the process parameters and the blurred/smeared appearance of the surfaces. At last, a correlation study of the standard/traceology parameters of the CSI measurements and the parameters evaluated from the CSW measurements is conducted. The preliminary results suggest that the CSW “Asymmetry” parameter reflects best the blurred/smeared appearance and in combination with other parameters can be used as diagnostic criteria for controlling the polishing process in production.

110 Abstract submitted to the www.metprops2019.org conference

Figure 1. Left: Polished surfaces with two different process parameters (columns) in two steps (rows); Right: CWS measurement (representation of “Asymmetry” parameter)

Figure 2. CSI measurements (10x objective). Left: surface from F4-area (15° tool angle); Right: surface from F2-area (20° tool angle).

Main References [1] Coherent Wave Scatter System 640, QSO Interferometer Systems AB, Halmstad, Sweden, http://qisab.com/products-solutions/products/cws640/, accessed January 30, 2019. [2] MicroXAM 100 HR, Phase Shift Technology, Tucson, Arizona, USA now owned by KLA- TENCOR CORPORATION, https://www.kla-tencor.com/products/surface-profilers, accessed January 30, 2019. [3] Thomas, T.R., Rosén, B-.G., Zahouani, H., Blunt, L. and El Mansori, M. (2011) Traceology, quantifying finishing machining and function: A tool and wear mark characterisation study. Wear 271 (3-4), pp. 553-558. [4] Dimkovski, Z. (2011) Surfaces of honed cylinder liners. Doctoral thesis, Chalmers University of Technology. [5] MATLAB version 9.3.0.713579 (R2017b), September 14, 2017, The Math Works Inc. www.mathworks.se/products/matlab, accessed January 30, 2019. [6] MountainsMap Premium version 7.0.6845, September 28, 2013, Digital Surf, www.digitalsurf.com, accessed January 30, 2019.

111 Abstract submitted to the www.metprops2019.org conference Conference 056

Case studies in X-ray computed tomography surface texture measurement

Adam Thompson1, Nicola Senin1,2, Richard Leach1 1Manufacturing Metrology Team, University of Nottingham, NG8 1BB, UK 2Department of Engineering, University of Perugia, 06125, Italy

E-mail: [email protected]

Keywords: surface texture measurement, additive manufacturing, X-ray computed tomography

Abstract. X-ray computed tomography (XCT) is now capable of achieving lateral resolutions that approach those achievable by optical and contact surface measurement systems [1,2]. As such, XCT has been used in the measurement of internal and difficult-to-access surfaces that are commonly found in additive manufactured (AM) parts [3]. However, the use of XCT for the measurement of surfaces in industries other than AM has been explored to a lesser extent, though interest in doing so has been shown by a number of industrial manufacturers as part of the European AdvanCT project [4]. Particularly, XCT has not been applied to the measurement of surfaces smoother than the typically rough (Sa > 1 μm) surfaces present in AM parts. In this work, we discuss the challenges of XCT surface measurement on injection moulded parts (figure 1a) and medical needles (figure 1b). Measurement data is acquired using XCT systems at the Danish Technological Institute and the University of Nottingham. Characterisation is based on the computation of ISO 25178-2 [5] surface texture parameters. XCT measurement is also compared to optical measurement via coherence scanning interferometry (CSI) [6], using quantitative topography comparison methods based on statistical topography modelling (presented elsewhere [3,7]). The studied surfaces are representative of a wide array of topographic patterns and surface textures, and thus present interesting scenarios for the investigation of XCT surface measurement behaviour and performance. In particular, the results show how the marginally lower lateral resolution of XCT surface measurement (when compared to optical measurement via CSI) affects both topographic reconstructions and the value of surface texture parameters when the spatial frequencies present on surfaces approach the minimum resolvable frequencies for the XCT systems. The results, therefore, show the ability of XCT to generate surface topography reconstructions as a result of the degree of texture present on the surface. Ultimately, the results presented in this work contribute to understanding the use of XCT surface measurement in a wide range of applications. We would like to acknowledge Novo Nordisk for supplying case studies, and the Danish Technological Institute for providing XCT data.

112 Abstract submitted to the www.metprops2019.org conference

a) b)

Figure 1. Example industrial parts to be measured during this case study: a) animal mask; b) insulin needle, courtesy of Novo Nordisk

References

[1] Thompson A, Senin N, Maskery I, Körner L, Lawes S and Leach R K 2018 Internal surface measurement of metal powder bed fusion parts Addit. Manuf. 20 126–133

[2] Townsend A, Pagani L, Scott P and Blunt L A 2017 Areal surface texture data extraction from x-ray computed tomography reconstructions of metal additively manufactured parts Precis. Eng. 48 254– 264

[3] Thompson A, Senin N, Maskery I and Leach R K 2018 Effects of magnification and sampling resolution in X-ray computed tomography for the measurement of additively manufactured metal Precis. Eng. 53 54–64

[4] EURAMET 2018 AdvanCT (Available at:https://www.euramet.org/research-innovation/search- research- projects/details/?eurametCtcp_project_show%5Bproject%5D=1535&eurametCtcp_project%5Bba ck%5D=450&cHash=b06586f1f7fa179c7c6a77e7539893ad Accessed 6 December 2018)

[5] ISO 25178-2 2012 Geometrical product specifications (GPS) -- surface texture: areal -- part 2: terms, definitions and surface texture parameters (International Organisation for Standardisation)

[6] de Groot P 2011 Coherence scanning interferometry. In: Optical measurement of surface topography ed Leach R K (Berlin, Germany: Springer-Verlag) pp 187–208

[7] Thompson A, Senin N, Giusca C and Leach R K 2017 Topography of selectively laser melted surfaces: A comparison of different measurement methods Ann. CIRP 66 543–546

113 Abstract submitted to the www.metprops2019.org conference

Conference 057

The Development of Long-Wavelength X-Ray Reflectivity for Thin Films Thickness Measurement in Semiconductor Industry Bo-Ching He, Guo-Dung Chen, Chun-Ting Liu, Wei-En Fu* and Wen- Li Wu* Center for Measurement Standards, Industrial Technology Research Institute, Hsinchu, Taiwan

E-mail: [email protected]; [email protected]

Keywords: X-Ray Reflectivity, Thin films, Thickness,

Abstract When semiconductor devices are keeping scaling, accurate and reliable monitoring of different thin film thickness is becoming critical to the quality of the chips in the advanced microelectronic devices. In semiconductor industry, the high-k/metal gate thickness will be reduced to several nanometers and even subnanometers for improved performance. Besides, the measured area will also be confined to tens of micrometers. The traditional optical measurement methods can no longer provide sufficient resolution and appropriate measurement area. Therefore, Long-wavelength X-ray reflectivity will be developed to solve these problems [1, 2, and 3].

Comparing to commercial XRR, Long-Wavelength X-ray reflectivity can increase incidence angle during reflectivity measurement shown as in Figure 1. Because of this, not only the measured area of our system can be down to 50x50 µm2 but the flux can be increased by using focus beam for raising the signal to noise ratio. Improvements in the Long-Wavelength x-ray reflectivity configuration were made to allow high-throughput in-line thin films inspection. Therefore, non-destructive XRR method can be provided as a powerful metrology tool for its fast and accurate measurement. The performance of a new in-line metrology tool will be addressed in the future.

In this study, we have developed the thin film thickness measurement system (shown in Figure 2) with an Al source X-ray which was constructed to provide accurate thickness measurements, and small footprint on film surface, since X- ray reflectivity is very sensitive to surface and interface roughness, and also provides information about film density.

The configuration of the constructed Long-Wavelength x-ray reflectivity is shown in Figure.3. The Al source can increase the incident angle during reflectivity measurement. As Long-Wavelength x-ray reflectivity already used Al source under grazing incidence and the variation of the angle of incidence, a θ-2θ goniometer was simulated by combining a photodiode and a Silicon Drift Detector (SDD). The photodiode is used to reduce the high count-rate of the

114 Abstract submitted to the www.metprops2019.org conference

direct and totally reflected beam at small angles, which exceeds the working range of the SDD.

In this study, the target high-k and metal films (four samples: 1. HfO2 50 nm / SiO2 / nm/ Si substrate, 2. HfO2 1.2 nm / SiO2 / nm/ Si substrate, TiN 2.0 nm / SiO2 / nm/ Si substrate, and 3. TaN 2.0 nm / SiO2 / nm/ Si substrate shown as Table 1) were deposited by atomic layer deposition (ALD). In this preliminary result, using this new setup to measure the thickness of high-k gate oxide (sample 1) is shown in Figure 4, incorporating TEM analyses. The TEM images show an unclear interface between each layer owing to the thickness and amorphous phase. Therefore, it is hard to actually define thickness. Besides, for comparing the difference of the commercial XRR and prototype XRR, we used the same sample (sample 2) to verify. In Figure 5, the S/N ratio in high angle reflectivity measurement is better and the thickness of HfO2 layer is 1.22 nm. In the future, we will present more experimental results.

Figure 1. The difference of the footprint between commercial XRR and Long-Wavelength XRR.

Figure 2. The image of the lab prototype.

115 Abstract submitted to the www.metprops2019.org conference

Figure 3. The new Long-Wavelength x-ray reflectivity metrology tool.

Figure 4. The reflectivity and TEM photo for HfO2 of thickness 50 nm.

Figure 5. The reflectivity measurement between commercial XRR and prototype for HfO2 of thickness 1.2 nm.

116 Abstract submitted to the www.metprops2019.org conference

TABLE 1. The information of measurement samples Sample number Sample structure Sample thickness 1 HfO2/SiO2/Si 50 nm 2 HfO2/SiO2/Si 1.2 nm 3 TiN/SiO2/Si 2 nm 4 TaN/SiO2/Si 2 nm

Main References

[1] Parratt L. Surface studies of solids by total reflection of x-rays. Phys. Rev.95:359–369,1954 [2] Heald S.M. X-ray reflectivity study of SiO2 on Si. J. Vac. Sci. Technol. A Vac. Surf. Films.;8:2046,1990. [3] F. Huang et al., “X-ray Reflectivity Studies of Thin Film”, Center for Materials for Information Technology, 2005.

117 Abstract submitted to the www.metprops2019.org conference

Conference 009

Integral analysis of selective laser melting of intermetallic NiTi and TiAl powder

M. Doubenskaia1, I. Smurov1,2, A. Sova1, P. Petrovskiy2

1Université de Lyon, Ecole Nationale d'Ingénieurs de Saint-Etienne (ENISE), LTDS Laboratory, 58 rue Jean Parot, 42023 Saint-Etienne Cedex 2, France

2National University of Science & Technology (MISIS), 4 Leninsky pr., 119049, Moscow, Russia

E-mail: [email protected]

Keywords: selective laser melting, intermetallic, optical diagnostic, thermal cycling.

118 Abstract submitted to the www.metprops2019.org conference

119 Abstract submitted to the www.metprops2019.org conference

SESSION 10

120 Abstract submitted to the www.metprops2019.org conference

Conference 058

Controlling the visual appearance and texture of injection moulded automotive components

A. Sjögren1 , B-G Rosen2, Vijeth Reddy2, Amogh V2 1Lund University, Department of Design Sciences 2Halmstad University, Functional Surfaces Research Group E-mail: [email protected]

Keywords: injection moulding, visual appearance, surface texture, gloss, surface imaging

Abstract: Interior automotive components are often manufactured by injection moulding since this technique enable cost efficient manufacturing, large design freedom, easy integration of functions, large flexibility regarding colour and surface texture, good sound absorption, etc. However, injection moulding of interior automotive components with required surface properties is difficult since a large number of material- and processing parameters influence the result [1-4]. In the present study, the effect on colour and gloss by melt temperature, tool temperature, and injection speed have been investigated. Design of experiments (DOE) has been used and test objects, based on polypropylene (PP) and acrylonitrile butadiene (ABS), have been manufactured in a tool for master plaques. The results show that none of the examined processing parameters had any effect on the colour of the manufactured test objects. Probably because the manufactured test objects were black. But the tool temperature and injection speed had large effect on the gloss, see Table 1. High tool temperature and/or high injection speed seems to be favourable to obtain low gloss. The melt temperature had, however, rather small effect on the gloss, which is surprising since results in the scientific literature indicate that high melt temperature is one of the most important processing parameters to obtain good reproduction of the texture in the tool and thereby low gloss [5,6]. The reason for the variation in gloss for the different processing parameters has been studied by surface imaging using GFM MicroCAD and MicroXam phase shift interferometry. The measured surfaces are characterized by areal surface parameters defined by ISO 25178-2:2012 [7]. These areal surface parameters are statistically screened to identify a set of robust parameters that best describe the variation in gloss. Parameters identified are for example; mean amplitude parameter, Sa; volume parameters, Vmc & Vv; and spatial parameter, Sal. The results from the surface imaging have been compared to results from microscopic examination of the injection moulded components and it is clear that different processing parameters result in very different reproduction of the tool surface pattern, see Figures 1 and 2. In the next step we will use the same surface imaging techniques and microscopy to study how the molecular weight distribution of the plastic material influence the tool surface reproduction, and also try to determine the internal pressure in the tool that is necessary to obtain perfect tool surface reproduction for different surface textures and different plastic materials.

121 Abstract submitted to the www.metprops2019.org conference

Table 1. Measured gloss for different processing parameters.

Melt temperature Tool temperature Injection speed Gloss [°C] [°C] PP ABS 200 20 Low 6.2 18.0 200 20 High 3.9 9.0 200 80 Low 4.1 4.7 200 80 High 3.4 3.9 280 20 Low 6.0 17.0 280 20 High 3.5 7.3 280 80 Low 3.7 6.3 280 80 High 2.8 3.4

a b

Figure 1. Results from scanning electron microscopy. The two micrographs show the surface texture of test objects manufactured out of (a) PP and (b) ABS.

Figure 2. Surface images of fine patterned ABS captured using (a) GFM MicroCAD (b)Interferometer

122 Abstract submitted to the www.metprops2019.org conference

Main References [1] F. Pisciotti, A. Boldizar, M. Rigdahl och I. Ariño, Effects of injection-molding conditions on the gloss and color of pigmented polypropylene, Polymer Engineering and Science (2005) 1557- 1567. [2] M.J. Oliveira, A.M. Brito, M.C. Costa och M.F. Costa, Gloss and surface topography of ABS: A study on the influence of the injection molding parameters, Polymer Engineering and Science (2006) 1394-1401. [3] B. Sha, S. Dimov, C. Griffiths och M.S. Packianather, Investigation of micro-injection moulding: Factors affecting the replication quality, Journal of Materials Processing Technology 183 (2007) 284-296. [4] F. Pisciotti, A. Boldizar, M. Rigdahl och I. Ariño, Effects of injection-molding conditions on the gloss and color of pigmented polypropylene, Polymer Engineering and Science (2005) 1557- 1567. [5] S. Ignell, U. Kleist och M. Rigdahl, Visual perception and measurements of texture and gloss of injection-molded plastics, Polymer Engineering and Science (2009) 344-353. [6] S. Nebo, Z. Ali och S. Scott, Replication of micro-feature using variety of polymer and commonly used mould at elevated temperature and pressure, IOP Conf. Series: Materials Science and Engineering 40 (2012) 1-8. [7] ISO 25178- Part 2: 2012, Geometrical product specifications (GPS)-surface texture; areal part 2: terms, definitions and surface texture parameters (International Organization for Standardization)

123 Abstract submitted to the www.metprops2019.org conference

Conference 063

Optical properties of micro-textured injected polymer parts

R. Labayrade1, A-C Brulez2,3, S. Valette2, E. Contraires2, S. Benayoun2 1P2E-LGCB, Ecole Nationale des Travaux Publics de l’Etat, Lyon University, 2LTDS- ECL, Lyon University, 3LGFMP, Institut Textile et Chimique de Lyon.

E-mail: [email protected]

Keywords: surface texture, polymer parts, micro-injection, BRDF.

Abstract (Intro-Background) Plastics and mould manufacturers are concerned by the visual aspect of injected plastic parts, particularly in the sectors of luxury packaging (vials) and in the automotive and aeronautics industries. These parts are light and allow a great flexibility of geometries and shapes that can be achieved at low unit costs. But their appearance is often associated with low-end products with a short lifespan. Yet it is possible, for a number of thermoplastic polymers, to control the reproduction, by micro-injection of surface patterns of parts whose size can be between 200 nm and 50 µm thus opening a wide spectrum of functionalities that can be transferred to these materials (superhydrophobia, water drop filmization, etc...). This study is aimed at understanding the relationships between the optical properties of injected polymer parts and their surface topography, and finally with the parameters of the implementation process; the long term goal being to master visual design by texturing their surface. (Materials and Methods) To produce the polymer parts, moulds were manufactured by texturing using femtosecond laser processing, resulting in sinusoidal topography with wave period around 650 nm and amplitude around 500 nm. Then, thermoplastic injection was performed in order to obtain textured parts of 1 to 2 cm², using polymethyl methacrylate (PMMA), polypropylene (PP) and polycarbonate (PC). The topographic characterization of parts used AFM, SEM and interferential profilometry. The optical properties were measured using spectral goniophotometer, in order to obtain the BRDF (Bidirectionnal Reflectance Distribution Function) of the polymer parts. (Predicted or current Results) Both surface topography and optical properties vary depending on the parameters of the implementation process, namely injection temperature, mould contact time and type of polymer (PMMA, PP or PC). The surface topography is derived from the mould topography and shows wave period around 650 nm and amplitude between 350 and 500 nm. Depending on the parts, the optical properties show different global reflectance factors, and different colours depending on the view angle and on the illumination angle. Spectral analysis indicates reflected light is not monochromatic, suggesting a complex iridescence phenomenon. (Possible or drawn Conclusions) In conclusions of the study, clear relationships between optical properties of injected polymer parts have been demonstrated: the optical properties of the mould insert have been transferred and modulated by the parameters of the implementation process. In particular, complex iridescence has been evidenced. (Future activities) In future works, a spectral BRDF predictive model will be

124 Abstract submitted to the www.metprops2019.org conference

derived from the experimental results, depending on injection temperature, mould contact time and type of polymer (PMMA, PP or PC).

125 Abstract submitted to the www.metprops2019.org conference

10µm 10µm

Figure 1. AFM analyses of the textured areas a) of the mold insert, and the corresponding replicated areas on the parts in b) polypropylene (PP) and c) polycarbonate (PC). Same xy scale for all 3 images.

Figure 2. Coated mold inserts and polycarbonate (PC) part injected using the CrNO insert. SEM image of the textured area of the part. Textured area: 10x10 mm², wave period  ~ 650 nm and amplitude H ~ 500 nm.

Figure 3. Visual aspect of two injected polymer parts, and two slices of their spectral BRDF, for various view and illumination angles

126 Abstract submitted to the www.metprops2019.org conference

Main References [1]P. Bizi-Bandoki, S. Benayoun, S. Valette, B. Beaugiraud, E. Audouard, Modifications of roughness and wettability properties of metals induced by femtosecond laser treatment, Applied Surface Science, 257 (2011) 5213-5218 [2] J. Vera, A.-C. Brulez, E. Contraires, M. Larochette, N. Trannoy-Orban, M. Pignon, C. Mauclair, S. Valette, S. Benayoun, Factors influencing micro injection replication quality, Journal of Micromechanics and Microengineering, 28 (2018) 015004 (12pp) [3] V. Belaud, S. Valette, G. Stremsdoerfer, M. Bigerelle, S. Benayoun, Wettability versus Roughness : multi- scales approach, Tribology International, 82 (2014) 343-34 [4] J. Vera, A.-C. Brulez, E. Contraires, M. Larochette, S. Valette and S. Benayoun, “Influence of the polypropylene structure on the replication of nanostructures by injection molding”, J. Micromech. Microeng. 25 115027 (2015) [5] J. Vera, A.-C. Brulez, E. Contraires M. Larochette, S. Valette and S. Benayoun, “Micro-texturing and microinjection of thermoplastics: a review”, Matériaux et Techniques, 105, 303 (2017) [6] R. Labayrade and P. Kopff High Radiance Image Display Systems And Associated Methods. Japan Patent Office, 11600950023, submitted by ENTPE (516170314) and Oktal Japan. May 2016, 2016-114780.

127 Abstract submitted to the www.metprops2019.org conference

Conference 047

A coupled method for characterizing the elasticity, firmness and tension effect of human skin surfaces in vivo: study of the influence of caring products in relation with age effect

M. Ayadh1,2, M-A. Abellan2, C. Didier2, A. Bigouret1, H. Zahouani2 1 Laboratoires Clarins, Pontoise, France 2 Université de Lyon-ENISE-LTDS-CNRS, France

E-mail: [email protected]

Keywords: human skin, in vivo, non-contact impact tests, chromatic confocal microscopy, natural tension, surface topography

Abstract Human skin is a thin envelope protecting the body from external biological, thermal, chemical and mechanical influences. It is extremely complex with a very developed sensory system. The skin is one of the main vectors of transmission of feelings of comfort and pain sent by our body as an indicator of its state. It provides an easy way for transdermal drug delivery or direct application of caring products. For these reasons, the human skin in vivo can provide relevant information in many areas of surgery, dermatology and cosmetology. The influence of aging on the evolutions of its response to various solicitations is also an important issue in medicine and cosmetics. The skin has a complex multilayer structure consisting of four main layers: the stratum corneum, the viable epidermis, the dermis and the hypodermis. The skin is made of non-homogeneous, non-linear, viscoelastic, anisotropic materials subjected to an in vivo pre-tension. It is established that this natural tension comes from the networks of collagen and elastin fibers embedded in the extracellular matrix of the dermis. The 3D organization of the collagen and elastin fibers initiates the multidirectional natural tensions in the skin volume. The state of these networks influences the surface topography of the skin. In other words, the topography of the skin surface is made of a 3D network of lines, folds and furrows. Each of them expresses the natural tensions developed by the collagen and elastin fibers in terms of amplitude (for example, high tension leads to deep furrows) and of direction (for example, the direction of a line indicates the orientation of fibers). It should be noted that the topography of the surface of the skin depends on the area of the body, on the age of the person and on her gender. This work presents a coupled method of characterization of the mechanical properties (elasticity, firmness and tension) of the human skin in vivo. Non-contact impact tests are performed using the WaveSkin® device of the LTDS to determine the elastic properties of the skin. In addition, skin replicas of the skin surface are taken. The surface prints are reconstructed by chromatic confocal microscopy and lead to an estimate of the properties of the skin surface: topography, firmness and tension. This coupled method is applied to investigate the influence of a cosmetic caring cream applied onto the outer surface of the skin of the forearm of six adult volunteers of different ages.

128 Abstract submitted to the www.metprops2019.org conference

Conference 005

Skin folding phenomenon investigation: insights on skin structural implication in folding

A Guillermin1,2, M Ayadh1,2, E Feulvarch2 , H Zahouani1 1 Laboratoire de tribologie et Dynamique des systèmes, UMR-CNRS 5513, École Centrale de Lyon, Université de Lyon, Écully, France 2 Laboratoire de tribologie et Dynamique des systèmes, UMR-CNRS 5513, École Nationale d’Ingénieurs de Saint Etienne, Université de Lyon, Écully, France

E-mail: amaury.guillermin@ec-lyon .fr Keywords: skin, surface texture, folding, wrinkling, phenomenon

Abstract: Skin folding is commonly used by surgeons to evaluate skin Langer's lines directions, accurate indicators of skin tension. Mechanically speaking, a folding solicitation is comparable to a compression on a volume, expect that it applies on a membrane, which is a 3D plan with a larger width than thickness. The clinical gesture operated by the surgeons is a folding on the epidermis of the skin, the last layer of the three skin strata. To understand the mechanical response to this load, the scientific methodology is based on the same folding technique to deduce mechanical insights on skin behaviour. The aim of the study is to compare imaging observations on skin surface and mechanical properties computed deeper to understand how mechanically skin response to folding. To recreate this surface perturbation, a folding device has been designed to observe the phenomenon. A non-invasive in vivo protocol has been developed to carry out measurements. To analyse the skin response, two different approach have been combined: one scanning topography and a second computing skin rigidity. This first method can measure microscopic topography on the surface of the human skin. The second method permits the speed propagation estimation of a wave at the surface of the skin. Both methods are carried out and computed on the same body area. Both results describe a typical behaviour of an anisotropy material. After folding, several changes occur as surface microstructure deepens and mechanical properties weakens. The relevant parameter is the spatial distribution of the measurements. While comparing anisotropy of measurements, privilege orientations in the spatial distribution arise. Indeed, skin microstructure is folded following main directions and wave propagation also speed up following main directions. These directions match closely in both measurements. Structural implication is visible in this correlation, where surface modifications match deep structure changes, witnessed by the speed variations. Finally, privilege orientations, on both - speed propagation and microstructure directions – measurement, show the implication of the structure in this surface solicitations. More, privilege orientations are closely aligned with Langer’s lines directions, which are roaming lines on skin surface characterizing

Abstract submitted to the www.metprops2019.org conference

Conference 075

Multiscale characterization of surface anisotropy

T Bartkowiak1, J Berglund2,3, C A Brown4 1Institute of Mechanical Technology, Poznan University of Technology, 2Department of Manufacturing, RISE IVF, 3Department of Industrial and Materials Science, Chalmers University of Technology, 4Surface Metrology Lab, Worcester Polytechnic Institute

E-mail: [email protected]

Keywords: surface texture, anisotropy, multiscale

Abstract Anisotropy is a factor that can influence surface function and be an indicator of processing. This includes tribological contacts in sheet forming, wetting, and dental microwear. This article exemplifies methods for quantification and visualization of anisotropy using 3D multiscale curvature tensor analysis and sliding bandpass filtering [1] prior to the calculation of ISO 25178 areal characterization parameters [2]. A milled steel surface, with evident anisotropy, and a microEDMed surface, an example of an isotropic surface, were measured with an interferometric and a confocal microscope respectively. The curvature tensor T is calculated using three proximate unit vectors normal to the surface [3]. The multiscale effect is achieved by changing the size of the sampling interval for the estimation of the normals. Normals are estimated from regular meshes by applying a covariance matrix method. The curvature tensors provide the two perpendicular directions on the surface with the most and the least curvatures (principal directions) and the bending radii (principal curvatures). The directions of the maximum curvatures are plotted for each of the regions and scales. In addition, 2D and 3D distribution graphs show anisotropic and isotropic characteristics. This facilitates determination of the dominant texture direction or directions for each scale. Those results are compared with sliding bandpass filter method [4]. Thereby revealing differences and limitations between the two multiscale methods. In contrast to commonly used surface isotropy/anisotropy determination techniques such as Fourier transform or autocorrelation, the presented method provides the analysis in 3D and for every region at each scale. Thus, different aspects of the studied surfaces are shown at different scales [5, 6].

Abstract submitted to the www.metprops2019.org conference

a) b)

Figure 1. Renderings of measured surfaces: a) isotropic, created by microEDM with 18nJ discharge energy, b) anisotropic, created by conventional milling

a) b)

Figure 2. Direction of maximal curvature calculated at scale equal to a) 2730 nm for milled texture and b) 375 nm for microEDMed sample

Main References [1] Brown CA, Hansen HN, Jiang XJ, Blateyron F, Berglund J, Senin N, Bartkowiak T, Dixon B, Le Goic G, Quinsat Y, Stemp WJ (2018) Multiscale analyses and characterizations of surface topographies CIRP annals 67 2 pp.839-862. [2] ISO 25178-2. Geometrical product specifications (GPS)—Surface texture: Areal—Part, 2. [3] Bartkowiak T (2017) Characterization of 3D surface texture directionality using multiscale curvature tensor analysis, Proceedings of the ASME 2017 International Mechanical Engineering Congress and Exposition IMECE17, November 3-9, 2017, Tampa, Florida, USA. [4] Berglund J, Wiklund D, Rosén B G (2011) A method for visualization of surface texture anisotropy in different scales of observation Scanning 33 5 pp 325–31. [5] Scott R S, Ungar P S, Bergstrom T S, Brown C A, Grine F E, Teaford M F, Walker A (2005) Denal microwear texture analysis within-species diet variability in fossil hominins Nature 436 4 pp 693- 95. [6] Thomas T R, Rosén B-G, Amini N (1999) Fractal characterisation of the anisotropy of rough surfaces Wear 232 1 pp 41–50.

129

Posters

130 Abstract submitted to the www.metprops2019.org conference Poster number : P01

Optical measurement of lead angle on rotary shafts

Peter de Groot, Michael Schmidt and Leslie Deck Zygo Corporation

E-mail: [email protected]

Keywords: surface texture, lead angle, twist, interferometry, slip seal, cross hatch

Abstract A frequent metrology task in precision engineering is the surface texture analysis of nominally cylindrical areas, including bearing and sealing surfaces on rotating shafts [1]. The machining process can leave signatures, intended or unintended, of the turning, grinding or honing process. These signatures often include groove bands, or more generally, a dominant direction or ensemble of direction for texture marks. The functional behaviour of sealing surfaces and bearings can be strongly dependent on the dominant texture direction with respect to the axis of rotation of a machined part. This is for example the case for twist or machining lead angle, which characterizes the orientation of the strongest texture direction with respect to the rotation axis. Following common usage in sealing surface characterization, and in analogy with terminology for screws and gears, the lead angle is the arctangent of the axial advance of the nominally helical structure of the surface texture during one complete turn.

Figure 1 illustrates the concept and geometry of lead angle. A cylindrical part has a rotation axis collinear with the global coordinate axis x . The 2D image of the surface in the right-hand portion of the figure shows a portion of the cylinder surface orthogonal to the z axis, with projection of the y axis illustrating the circumferential direction of rotation of the cylinder. The 2D image shows a dominant directionality to the surface texture, here illustrated by groove bands, which define a lead angle D between the surface texture direction and the circumferential rotation direction [2, 3].

A traditional mechanical means for detecting measuring lead angle involves the suspended weight or thread method, as detailed for example in ref.[4]. More recently, this traditional technique has been supplanted by methods based on mechanical stylus measurements [5, 6]. However, contact stylus instruments only sample profiles over a range of rotation angles, and do not provide a full 3D image for detailed texture analysis.

Non-contact methods of examining surface texture rely on an optical areal surface topography map [7]. Full 3D surface topography measurement provides detailed texture analysis, enabling accurate determination of the dominant surface texture direction, for example by the standardized surface texture direction parameter Std [8]. Several fit and removal strategies have been 1 131 Abstract submitted to the www.metprops2019.org conference

developed to determine the relative orientation of the global coordinates of the part with respect to the local coordinates of the areal surface topography image, followed by an analysis to determine the surface texture direction [9-12]. The measurement is exceptionally challenging, in that the requirement is to control the lead angle to D <0.05˚, which implies 0.005˚ gage capability. This is more than an order of magnitude beyond the resolution of the Std parameter in standard commercial software.

Here we present our lead angle solution using interference microscopy, multi- axis staging, and advanced software for determining the parameter with a precision of 0.001 deg and a reproducibility of 0.005˚.

Circumferential Global coordinate y´ Surface texture rotation direction system aligned to the direction axis of rotation y´ Cylindrical part x´ x´

z´ 2D image of surface texture aligned to global coordinates

Lead angle Dγ

Figure 1. Geometrical definition of the machining lead angle for a cylindrical part.

Figure 2. Experimental geometry (left) and example topography (right) for a shaft measurement.

2 132 Abstract submitted to the www.metprops2019.org conference

References

[1] Beyerer, J (1995) Model-based analysis of groove textures with applications to automated inspection of machined surfaces. Measurement 15 pp 189-199 [2] Puente León, F, Rau, N (2003) Detection of machine lead in ground sealing surfaces. Annals of the CIRP 52/1/2003 pp 459-462 [3] Seewig, J, Hercke, T (2009) Lead characterisation by an objective evaluation method. Wear 266 pp 530-533 [4] RMA OS-1-1 (2004) Shaft finish requirements for radial lip seals [5] Hercke, T, Schloz (2009) MBN 31 007-7: Measurement and Evaluation Method for the Assessment of Lead-Reduced Dynamic Sealing Surfaces [6] Seewig, J, Hercke, T (2009) 2nd Generation lead mesurement. Proc. IMEKO World Congress 1957-1961 [7] Shuster, M, et al. (2002) Development of the Methodology for 3-D Characterization of Oil Seal Shaft Surfaces. SAE International pp [8] ISO 25178-2 (2012) Geometrical product specifications (GPS) — Surface texture: Areal — Part 2: Terms, definitions and surface texture parameters [9] Xin, B (2007) Evaluation of two and a half-dimensional surface data with form component and groove bands. Machine Vision Applications in Industrial Inspection XV 6503 835-844 [10] Xin, B (2008) Auswertung und Charakterisierung dreidimensionaler Messdaten technischer Oberflächen mit Riefentexturen. Thesis, Fakultät für Mashinenbau, [11] Novak, E, Munteanu, F (2017) Optical measurement of lead angle of groove in manufactured part. US Patent 9,752,868 [12] de Groot , P, Deck, L L (2018) Surface topgraphy apparatus and method. US Patent 20180180412

3 133 Abstract submitted to the www.metprops2019.org conference

Poster number : P02

Designing CAD Model of the Gap Between Freeform Surfaces

M Poniatowska1, D Groch1 1Bialystok University of Technology, Faculty of Mechanical Engineering

E-mail: [email protected]

Keywords: freeform surface, accuracy of fitting, CAD model of the gap, regression analysis, spatial statistics

Abstract: Applying injection molds has become one of the main production methods in the modern manufacturing industry. The increasing demand for the geometric accuracy of products forces an increase in the accuracy of molds used in their production. In addition to the product quality, the accuracy of mold producing must ensure the proper functioning of the mold itself. One of the important problems in injection mold processing is to ensure the accuracy of fitting of the closing surfaces that are often freeform. Deviations of the actual surfaces from the nominal form cause leaks in the closure and, as a result, material leakage. The present paper proposes a new method for designing of the CAD model of the gap between freeform surfaces which represents the accuracy of their fitting. For this purpose, the CAD models of both actual surfaces should be determined on the basis of the coordinate measurement data obtained in measurements along a regular grid of points in the UV space. The NURBS regression surface is modelled on the measurement data, and an adequate regression model is sought using the iterative procedure. In the following steps of the procedure, the number of control points and/or the degree of the surface is/are changed, and the autocorrelation of the model residuals is tested with the use of the spatial statistics methods. The designated model is a CAD representation of the actual surface. The accuracy tests of the surface fitting are carried out virtually by fitting together both models in the CAD software. The outcome of the study was a spatial model of the gap between the surfaces. Our experimental research was carried out on milled samples imitating the closing freeform surfaces of the injection mold. The surface profile heights, determined in coordinate measurements, were 0.0149 mm and 0.0299 mm, while the maximum width of the gap model after their closure was 0.0284 mm. The experimental verification of the gap model dimensions with the use of confocal and measuring microscopes for measuring the actual gap showed differences by an average of 10%. Such results justify the application of the model developed by us to represent the gap between the surfaces in analyzing the injection mold accuracy. On this basis, corrections may be calculated to compensate for any machining errors and the errors of both surfaces might be corrected by modifying the nominal CAD model and then by additional machining of only one of the two surfaces.

1 134 Abstract submitted to the www.metprops2019.org conference

Figure 1. The CAD model of the gap between surfaces.

Table 1. Results of comparative tests (mm)

Point Gap model Actual gap coordinates dimensions dimensions* x [mm] y 4.380 4.856 0.0278 0.0314 4.380 15.103 0.0228 0.0238 4.380 35.406 0.0180 0.0185

4.380 41.480 0.0155 0.0140 12.048 6.931 0.0248 0.0272 12.048 23.219 0.0184 0.0214 12.048 33.353 0.0210 0.0241 12.048 39.456 0.0103 0.0090 *the mean of 5 measurement results

Main References [1] Li Y, Gu P (2004) Free-form surface inspection techniques state of the art review Comput.-Aided Des. 36 pp 1395-1417 [2] Poniatowska M (2012) Deviation model based method of planning accuracy inspection of freeform surfaces using CMMs Measurement 45 pp 927–937 [3] Sladek J A (2016) Coordinate Metrology: Accuracy of Systems and Measurements (Springer, Berlin Heidelberg) [4] Poniatowska M (2015) Free-form surface machining error compensation applying 3D CAD machining pattern model Comput.-Aided Des. 62 pp 227-235 [5] Upton G J G, Fingleton B (1985) Spatial Data Analysis by Example Vol. 1 (John Wiley & Sons, New York) [6] Piegl L, Tiller W (1997) The NURBS book, (2nd ed., Springer-Verlag, New York)

2 135 Abstract submitted to the www.metprops2019.org conference Poster number : P03

Relationship between tyre rolling resistance and road surface macrotexture – Laboratory testing and modelling

E Riahi1, C Ropert1, M-T Do1 1 IFSTTAR, AME-EASE, 44344 Bouguenais, France

E-mail: [email protected]

Keywords: rolling resistance, macrotexture, laboratory test, modelling

Abstract: Rolling resistance is an important parameter in the vehicle fuel consumption and consequently the CO2 emission. It is defined as the energy loss per distance travelled by the vehicle and originates from the viscoelastic deformation of the tyre rubber. Usually, rolling resistance is measured on road sections by instrumented trailers or vehicles. Despite valuable data collected [1, 2], this method requires an important time and money investment, and the measurement is inherently disturbed by environmental conditions (e.g. wind, temperature). On the other hand, a laboratory test not only has the advantage to be faster and more economic, but also it can be carried out in controlled conditions allowing to understand the involved physical phenomena.

In this paper, a test method is first presented to characterise the rolling resistance in laboratory. The test machine is equipped with metallic rollers covered with a layer of rubber and mounted on a rotary head. The rolling speed can be adjusted and the torque moment measured during the rotations of the head is used to calculate a coefficient of rolling resistance (Crr). To assess the relevance of the method, 8 surfaces representative of actual road surfaces and 2 smooth surfaces are tested. Samples are cores taken from road sections or machined circular discs (for the smooth surfaces). Circular height profiles are measured on the surface of the samples using a non-contact laser sensor. Roughness parameters are calculated from the profiles to characterize the surface macrotexture. Results show a linear variation of the coefficient of rolling resistance with the Mean Profile Depth (standardized parameter used in the road field and has the same meaning as the average maximum profile peak height Rpm) (Figure 1). This variation corroborates that obtained by trailers on road sections with similar surface macrotexture (Figure 2).

Modelling of the hysteresis deformation of rubber, taking into account the surface texture and the rubber properties, is underway to explain on the on hand the relationship between tyre rolling resistance and surface macrotexture and, on the other hand, the good agreement between laboratory and in situ measurements. The developed model should allow to understand the difference – due to a scale effect – between the two types of measurements. Coupling of

1 136 Abstract submitted to the www.metprops2019.org conference

this model with a multiscale analysis of the road profiles would also provide new insights into the role of road surface texture scales.

2 137 Abstract submitted to the www.metprops2019.org conference

Crr Evolution with MPD 0,15 0,14 0,13

Crr 0,12 y = 0,0107x + 0,1219 0,11 R² = 0,7582 0,1 0 0,2 0,4 0,6 0,8 1 1,2 1,4 1,6 MPD (mm)

Figure 1. Evolution of rolling resistance coefficient with mean profile depth

0,15 9,0E-03

) 0,14 8,0E-03

0,13 7,0E-03 (In situ)(In Laboratory

( 0,12 6,0E-03

LaboratoireLaboratory results Crr Crr 0,11 5,0E-03 InIn situ situ MIRIAM results 2011 0,10 4,0E-03 0 0,2 0,4 0,6 0,8 1 1,2 1,4 1,6 MPD (mm)

Figure 2. Comparison between laboratory (this study) and in-situ results (from [2])

Main References [1] Descornet G (1990) Road-surface influence on tire rolling resistance, Surface Characteristics of Roadways: International Research and Technologies STP 1031. American Society for Testing and Materials [2] Sandberg U, Bergiers A, Ejsmont J A, Goubert L, Karlsson R, Zöller M (2011) Road surface influence on tyre/road rolling resistance Models for rolling resistance In Road Infrastructure Asset Management systems (MIRIAM)

3 138 Abstract submitted to the www.metprops2019.org conference Poster number : P04

Comparison of measurements of ISO material measures using a coherence scanning interferometer and a traceable contact stylus instrument

Rong Su1, Xiaoqian Cui1,2, Carlos Gomez1, Matthew Thomas1, Nicola Senin1, Peter de Groot3, Richard Leach1 1University of Nottingham, Manufacturing Metrology Team, 2Dalian University of Technology, 3Zygo Corporation

E-mail: [email protected]

Keywords: Surface metrology, coherence scanning interferometry, stylus instrument, roughness

Abstract: Optical surface measurements often outperform traditional mechanical methods in that they reduce surface damage, have high resolution, can allow improved accessibility, and operate at relatively high speed, therefore, allowing dense areal topography measurement. One of the most accurate optical techniques is coherence scanning interferometry (CSI), which uses interference fringe contrast and phase to determine surface heights [1]. However, lack of confidence in optical methods [2] has been a barrier that complicates the transition from traditional stylus instruments to optical areal measurements for routine measurement of surface texture and form. Optical surface measuring instruments can often be used in more than one operation mode, and different results with certain surfaces can be observed depending on the mode of operation and data processing [3]. Discrepancies in texture measurement results between CSI and stylus instruments have been observed in some cases [4]. The uncertainty of measurement would increase with the complexity of surface geometry, e.g. for surfaces that feature high slope angles, large curvatures on both macro- and micro-scales. Such surfaces significantly challenge the use of optical measuring techniques. In this work, we compare the surface measurement results for a CSI system and for a stylus instrument. The measurements are performed using a series of ISO material measures made from electroformed nickel, including random textures and sinusoidal surfaces with varying pitches and amplitudes [5], and the uncertainty evaluation for both optical and stylus measurements is provided. We also report on the potential of advanced signal correction techniques to improve correlation on steeply-sloped surface areas [6]. This work can be considered as an update on similar work in 2011 [7], and it shows that a good correlation between CSI and the stylus measurements can be achieved. The result shows the progress towards the full adaptation of optical methods for surface measurement.

Main References

[1] de Groot P (2015) Principles of interference microscopy for the measurement of surface topography. Adv. Opt. Photon. 7:1-65. [2] Rhee H-G, Vorburger T V, Lee J W, Fu J (2005) Discrepancies between roughness measurements obtained with phase-shifting and white-light interferometry. Appl. Opt. 44:5919.

1 139 Abstract submitted to the www.metprops2019.org conference

[3] Gomez C, Thompson A, Su R, DiSciacca J, Lawes S, Leach R K (2017) Optimisation of surface measurement for metal additive manufacturing using coherence scanning interferometry. Opt. Eng. 56:111714. [4] Gao F, Leach R K, Petzing J, Coupland J M (2008) Surface measurement errors using commercial scanning white light interferometers. Meas. Sci. Technol. 19:015303. [5] ISO 25178-70 2012 (2014) Geometrical product specifications (GPS) - Surface texture: Areal - Part 70: Material measures (International Organization for Standardization, Geneva) [6] Su R, Wang Y, Coupland J M, Leach R K (2017) On tilt and curvature dependent errors and the calibration of coherence scanning interferometry. Opt. Express 25:3297-3310. [7] Badami VG, Liesener J, Evans C, de Groot P. (2011) Evaluation of the measurement performance of a coherence scanning microscope using roughness specimens. Proc. ASPE, Denver, USA.

2 140 Abstract submitted to the www.metprops2019.org conference

Poster number : P05

Experimental study of the influence of chemically aided drag finishing on the surface integrity of aluminium and steel workpieces

I. Malkorra1,2, F. Salvatore 2, P. Arrazola 1, J. Rech 2 1 Faculty of Engineering, Mondragon University, 2500 Arrasate, Spain, 2 Univ. Lyon, ENISE, LTDS, UMR CNRS 5513, 58 rue Jean Parot, 42023 Saint-Etienne, France

E-mail: [email protected]

Keywords: drag finishing, mass finishing, chemical-mechanical, surface topography, residual stresses.

Abstract (Intro-Background) Modern machinery components require not only dimensional and geometrical accuracy, but also high quality of surface finish in order to ensure their adequate functional performance and longer service life. Mass finishing methods enhance surface defects of parts produced by the aggressive conventional machining processes (turning, milling, etc.). These free abrasive finishing processes consist on the action of rubbing between loose abrasive particles and workpieces to be treated, reaching very low roughness values, compressive residual stresses and high surface hardness. This process is used in automotive industry, medical implants, surgical material and aerospace and land turbine industries, where components have to operate in extreme environments. [1][2] As these techniques are versatile and the changes of process parameters can result in different surface effects, the understanding of the mechanism is essential to optimize process time and costs. Few researches have been carried out to understand mass finishing processes, most of them study the effect of input parameters, normally in surface roughness, like type of motion imparted to the workpiece or media [1][3][4][5][6][7], the size and shape of the abrasive particle [8][9][10][11][6][12], the velocity or frequency of the motion [8][13][14][15][16][17][18][19][20] and the lubricants of chemical accelerators [9][21][22][8].

(Materials and Methods) This research has been conducted in order to contribute to the understanding of these processes by means of the study of drag finishing process effects on surface integrity: topography and residual stresses. The investigation has been performed with samples of medium carbon steel (C45) and aluminium (6061T6) manufactured by subtractive techniques. Ten samples were subjected to drag finishing with a speed of 0.75 m/s (see Table 1). Spherical media was used, composed of alumina abrasive grains and ceramic bonder. The variable input parameters are the media diameter (5 and 1 mm), initial surface roughness (1.5 and 0.2 µm), and the type of liquid medium added to the chamber (a lubricant or a chemical accelerator dissolved in water). Topography measurements have been made with the optical microscope ALICONA Infinite Focus before, during and after drag finishing to analyse

1 141 Abstract submitted to the www.metprops2019.org conference

surface evolution. The range of measured values for the surface of Ra was 0.1– 2 µm, thus profile lengths of 4 mm have been evaluated, using an Lc filter of 800 µm. Like Figure 1 shows, 2D measurements and 3D images have been made in the workpiece surface. From 2D profiles Ra, Rsm and Rsk values have been analysed. Furthermore, surface profiles have been extracted to overlap them and to see graphically the profile evolution. Referential indents and scratches have been made on the surface to make accurate measurements. Figure 1 shows the measurement strategy for the graphs of the evolution of the surface profile.

(Current Results) Figure 2 shows the evolution of surface given in almost all cases. Figure 3 and Figure 4 show Ra evolutions during the process. Results show the next general trends: (1) fast peak removal is obtained with big media since they create higher impact forces. (2) Roughness tends to saturate, so, if the initial roughness of the surface is lower than the saturation value, media action will increase Ra. (3) The final surface has compressive residual stresses (-400 MPa), low surface roughness, uniform and isotropic surface. (4) Surface modification is accelerated if some specific chemical products are added to the drag finishing process.

(Drawn Conclusions) In conclusions of the study, there is still a lot of work to do to quantify the material removal during drag finishing, and how this changes the workpiece form. In addition, the creation of oxide and how this is removed by mechanical action has to be investigated. These will be the next steps for getting closer to the understanding of tribofinishing processes.

2 142 Abstract submitted to the www.metprops2019.org conference

Figures, tables and main references added on separate pages below:

Figure 1. Surface texture, profile and roughness measurement strategy.

Figure 2: Surface texture, profile and roughness parameter evolution.

3 143 Abstract submitted to the www.metprops2019.org conference

Figure 3. Ra evolution during tribofinishing process in steel samples.

Figure 4. Ra evolution during tribofinishing process in aluminium samples.

4 144 Abstract submitted to the www.metprops2019.org conference

Table 1. Design of experiments. Process time, workpiece material, initial surface roughness of the workpiece, size of media and the additive used for each sample are specified.

N° Process Material Initial Ra Media Ø Additive time (min) (µm) (mm)

S-1 160 Steel 1.5 5 A (Lubricant)

S-2 160 Steel 0.5 5 A (Lubricant)

S-3 160 Steel 1.5 1 A (Lubricant)

S-4 160 Steel 0.5 1 A (Lubricant)

S-5 160 Steel 1.5 5 B (Chemical accelerator)

S-6 160 Aluminium 1.5 5 A (Lubricant)

S-7 80 Aluminium 0.5 5 A (Lubricant)

S-8 80 Aluminium 1.5 1 A (Lubricant)

S-9 80 Aluminium 0.5 1 A (Lubricant)

S-10 80 Aluminium 1.5 5 C (Chemical accelerator)

5 145 Abstract submitted to the www.metprops2019.org conference

Main References

[1] I. Hilerio and T. Mathia, “Interface mass transfer during the tribofinishing process,” J. Mater. Process. Technol., vol. 209, no. 20, pp. 6057–6061, Nov. 2009.

[2] S. Yang and W. Li, Surface Finishing Theory and New Technology. Berlin, Heidelberg: Springer Berlin Heidelberg, 2018.

[3] F. Hashimoto and S. P. Johnson, “Modeling of vibratory finishing machines,” CIRP Ann. - Manuf. Technol., vol. 64, no. 1, pp. 345–348, Jan. 2015.

[4] Y. S. Kang, F. Hashimoto, S. P. Johnson, and J. P. Rhodes, “Discrete element modeling of 3D media motion in vibratory finishing process,” CIRP Ann., vol. 66, no. 1, pp. 313–316, Jan. 2017.

[5] R. E. Garlinghouse and H. . Hanz, “Heavy Duty Mass Finishing.” MI:Society of Manufacturing Engineers (SME), Dearborn, 1985.

[6] E. Uhlmann, A. Dethlefs, and A. Eulitz, “Investigation of Material Removal and Surface Topography Formation in Vibratory Finishing,” Procedia CIRP, vol. 14, pp. 25–30, Jan. 2014.

[7] V. Schulze, J. Gibmeier, and A. Kacaras, “Qualification of the stream finishing process for surface modification,” CIRP Ann. - Manuf. Technol., vol. 66, no. 1, pp. 523–526, Jan. 2017.

[8] X. Song, R. Chaudhari, and F. Hashimoto, “Experimental Investigation of Vibratory Finishing Process,” in Proceedings of the ASME 2014 International Manufacturing Science and Engineering Conference (MSEC2014-4093), 2014, vol. 2, pp. 1–7.

[9] S. Wang, R. S. Timsit, and J. K. Spelt, “Experimental investigation of vibratory finishing of aluminum,” Wear, vol. 243, no. 1, pp. 147–156, Aug. 2000.

[10] A. Mohajerani and J. K. Spelt, “Erosive wear of borosilicate glass by low velocity unidirectional impact of abrasive spheres,” Wear, vol. 270, no. 11–12, pp. 866–875, May 2011.

[11] J. E. Ritter, “Erosion damage in structural ceramics,” Mater. Sci. Eng., vol. 71, pp. 195–201, May 1985.

[12] P. K. Prakasam, S. Castagne, and S. Subbiah, “Mechanism of Surface Evolution in Vibratory Media Finishing,” Procedia Manuf., vol. 1, pp. 628–636, Jan. 2015.

[13] V. Pandiyan, S. Castagne, and S. Subbiah, “High Frequency and Amplitude Effects in Vibratory Media Finishing,” Procedia Manuf., vol. 5, pp. 546–557, Jan. 2016.

[14] D. Ciampini, M. Papini, and J. K. Spelt, “Characterization of vibratory finishing using the Almen system,” Wear, vol. 264, no. 7–8, pp. 671–678, Mar. 2008.

[15] A. Mohajerani and J. K. Spelt, “Erosive wear of borosilicate glass edges by unidirectional low velocity impact of steel balls,” Wear, vol. 269, no. 11–12, pp. 900–910, Oct. 2010.

[16] D. Ciampini, M. Papini, and J. K. Spelt, “Impact velocity measurement of media in a vibratory finisher,” J. Mater. Process. Technol., vol. 183, no. 2–3, pp. 347–357, Mar. 2007.

6 146 Abstract submitted to the www.metprops2019.org conference

[17] A. Mohajerani and J. K. Spelt, “Numerical modeling of the edge rounding of brittle materials by vibratory finishing,” Wear, vol. 268, no. 7–8, pp. 1002–1012, Mar. 2010.

[18] M. Barletta, F. Pietrobono, G. Rubino, and V. Tagliaferri, “Drag finishing of sensitive workpieces with fluidized abrasives,” J. Manuf. Process., vol. 16, no. 4, pp. 494–502, Oct. 2014.

[19] “V-Max® from Hammond Roto-Finish: The Latest Evolution in Spiratron® Deburring Technology,” Met. Finish., vol. 111, no. 3, pp. 52–53, May 2013.

[20] A. Kacaras, J. Gibmeier, F. Zanger, and V. Schulze, “Influence of rotational speed on surface states after stream finishing,” Procedia CIRP, vol. 71, pp. 221–226, Jan. 2018.

[21] M. R. Baghbanan, A. Yabuki, R. S. Timsit, and J. K. Spelt, “Tribological behavior of aluminum alloys in a vibratory finishing process,” Wear, vol. 255, no. 7–12, pp. 1369–1379, Aug. 2003.

[22] D. E. Semones and W. H. Safranek, “Chemically Accelerated Metal Finishing Process,” US3979858A, 1975.

7 147 Abstract submitted to the www.metprops2019.org conference

Poster number : P06 Effect of Geometric shapes on the Hydrodynamic Lift of the Cutting Tool Performance with Micro- Scale Surface Texturing

S Meena1, D Vasumathy2, A Meena3 Indian Institute of Technology Madras, Department of Mechanical Engineering

E-mail: [email protected]

Keywords: Micro-scale; Surface texture; Hydrodynamic lift; Cutting tools.

Abstract

Surface texturing promotes effective lubrication that can help in overcoming the various machining difficulties encountered and thus enhancing the cutting tool performance. The present study is thus mainly investigating the effects of micro-scale surface texturing on the hydrodynamic lubrication for differently shaped grooves by developing an analytical model at the tool-chip interface. The non-dimensional Reynolds equation was solved by the Gauss-seidal method to study the micro-scale textured surface. The effect of various shapes such as parabolic, triangular and rectangular shaped micro-grooves on the dimensionless average pressure and other parameters were analyzed to understand the Hydrodynamic lift. The cutting performance of the textured tools at different lay directions with respect to the chip flow indicated that the diagonal micro-grooves have the best cutting performance irrespective of the groove shape. Results show that the deep and narrow width grooves enhance the hydrodynamic lift. Moreover, the textured cutting tool is more effective at higher cutting speeds. The triangular micro-grooves gave better results when compared to the parabolic and rectangular shaped grooves. Therefore, designing the textured surface by considering all the parameters involved, the groove geometry and shape is very important to generate additional hydrodynamic pressure.

1 148 Abstract submitted to the www.metprops2019.org conference

Main References

[1] Kang Z, Ji J (2016) Numerical Investigation of Microtexture Cutting Tool on Hydrodynamic Lubrication, Journal of Tribology 139(5),054502. [2] Ji J (2014) Inﬂuence of Geometric Shapes on the Hydrodynamic Lubrication of a Partially Textured Slider with Micro-Grooves, Journal of Tribology 136(4):041702. [3] Uddin M S, Liu Y W (2014) Design and optimization of a new geometric texture shape for the enhancement of hydrodynamic lubrication performance of parallel slider surfaces, Biosurface and Biotribology 2 59-69. [4] Vasumathy D, Meena A (2017) Inﬂuence of micro scale textured tools on tribological properties at tool-chip interface in turning AISI 316 austenitic stainless steel, Wear 376-377 1747– 1758334. [5] Gropper D, Wang L, Harvey T J (2016) Hydrodynamic lubrication of textured surfaces: A review of modeling techniques and key findings, Tribology International 94 509–529.

2 149 Abstract submitted to the www.metprops2019.org conference

Poster number : P07

Robust Evaluation Method of Skewness and Kurtosis based on Probability Density Functions

M Uchidate1,2, Y Sasaki2,1, K Narita1 1Iwate University, Department of Science and Engineering

E-mail: [email protected]

Keywords: surface texture, parameters, skewness, kurtosis, probability density functions

Abstract (Intro-Background) Surface texture plays an important role in controlling friction and wear. The amplitude parameters such as Ra or Rz are commonly used to control their properties. The surface texture parameters such as skewness and kurtosis reflect height distribution of surfaces, which cannot be evaluated by the amplitude parameters. However, these parameters are known to be highly sensitive to outliers and very unstable since the third and fourth power of the height are included in their definition; i.e. the value of the third and fourth power of the outliers have huge impact on the parameter value. This unstable nature limits the application in practice. The objective of this paper is to propose a robust evaluation method of skewness and kurtosis based on probability density functions.

The robust evaluation method consists of two steps; fitting of a probability function and evaluation of the parameters (skewness and kurtosis) based on the fitted distribution. As the probability density function, the Pearson Type IV and Johnson SU were selected since these distributions have unbounded support and analytical values of skewness and kurtosis can be obtained using fitting parameters of the respective distribution. These distribution were fit by using the maximum-likelihood method.

The proposed evaluation method are validated with computationally generated datasets, which have selected fitting parameter values, using the acceptance-rejection method. Then, the proposed method was applied to datasets of areal surface texture obtained by a stylus instrument. Results have shown that the proposed method yields more robust values of skewness and kurtosis than the values using the original difinitions.

1 Poster number : P08 150 Abstract submitted to the www.metprops2019.org conference

Influence of Laser Powder Bed Fusion process parameters on the surface generation of Al10SiMg parts

E. Masiagutova1, F. Cabanettes1, G. Bidron2 , H. Si-Mohand1,2, A. Sova1, M. Cicci1 , P. Bertrand1 1University of Lyon, ENISE, Laboratoire de Tribologie et Dynamique des Systèmes, CNRS UMR 5513, 58 rue Jean Parot, 42023, Saint-Etienne, France 2Manutech USD, 20 rue PR Benoit Lauras, 42000, Saint-Etienne, France E-mail: [email protected] Keywords: Surface topography, Selective Laser Melting, AlSi10Mg, Processing parameters, Surface generation. Abstract In recent years, the use of emerging technologies such as Additive Manufacturing (AM) is stirring the industry. Thus, the aerospace and automotive industries are particularly attracted by Additive manufacturing which allows creating freeform parts with near net shape surfaces. AM represents a group of processes in which the material is added layer by layer [1-2]. Among AM techniques Selective Laser Melting (SLM) technology also known as Laser Powder Bed Fusion (LPBF) allows obtaining complex parts with high precisions. One of the most popular alloys, which find a large number of applications in the aforementioned industries, is aluminum-silicon alloy. AlSi10Mg alloy presents an excellent combination of low weight and good mechanical properties with high heat conductivity. The usage of such material combined with the advantages of the SLM process can lead to new opportunities: for example applications that require complex structures and internal cavities such as complex heat exchangers or lightweight structures [3]. Despite these appealing properties, to date the obtainable surface roughness (top surface Ra: 8 to 20 µm, side surface Ra 28 to 45 µm, [4, 6]) is a limitation for the industrial implementation of this. Furthermore, AlSi10Mg parts produced by SLM are usually rougher than if produced with other AM metals. Indeed Aluminum alloy AM production is usually submitted to balling and dross formation effects in the melt pool. And partially melted powders are often attracted to such generated AM samples [4]. State of the art clearly shows that a number of process parameters can control the surface quality of parts. They can be divided into two main categories: powder properties and process parameters [5]. Many articles focus on the influence of these factors on densification, microstructure, and mechanical properties of the final parts [2-3, 7]. However only a few articles show the factors influence on surface roughness [5, 6]. Furthermore they mainly focus on Ra parameter as a surface quality indicator. In addition to this parameter, it is necessary to consider other roughness parameters to achieve better understanding of surface generation. This article proposes to study the influence of various SLM process and powder parameters on the surface generation of AlSi10Mg parts using different types of roughness evaluation. The work was performed with a ProX 200 SLM machine from 3D system®, and a parameter window was first found to obtain an optimized density. Afterwards, based on this first optimization, the following parameters were slightly changed to observe the 151 Abstract submitted to the www.metprops2019.org conference

surface roughness variations: laser parameters, scan strategies, post-scanning strategies, powder size distribution. To observe topographies and material density the following evaluation methods were respectively used: • Archimedes’ Method for determining the density of each of the AM samples; • Focus Variation Microscope for acquiring top and side surface topographies (with size 4x3mm, lateral resolution 2µm and vertical resolution 50nm). The obtained topographies were post treated by a form removal filter (polynom of order 2). No further filters were applied. • Scanning electron microscope (SEM) for the topographic observation of surfaces. Preliminary results concern the repeatability of the process. Afterwards, the results are emphasizing the most important parameters and strategies able to reduce the surface roughness (both top and side surfaces). Then a detailed study of different roughness parameters is performed in order to better understand the surface generation during the Additive Manufacturing process. Furthermore a relationship between surface roughness and material density is established meaning that both optimizations can be performed in parallel.

Figure 1. Focus Variation Microscope for the acquisition of AlSi10Mg topographies generated by Selective Laser Melting / Laser Powder Bed Fusion

Figure 2. Relationship between surface topographies and sample porosity as a function of process energy density 152 Abstract submitted to the www.metprops2019.org conference

[1] M. Attaran, The rise of 3-D printing: The advantages of additive manufacturing over traditional manufacturing, School of Business & Public Administration, California State University, Bakersfield, USA (2017) 1–12. [2] F. Trevisan, F. Calignano, M. Lorusso, J. Pakkanen, A. Aversa, E. P. Ambrosio, M. Lombardi, P. Fino and D. Manfredi, On the Selective Laser Melting (SLM) of the AlSi10Mg Alloy: Process, Microstructure and Mechanical Properties, Materials, DISAT, Department of Applied Science and Technology, Politecnico di Torino, (2017) 1-23. [3] K. Kempen, L. Thijs, J. Van Humbeeck and J.P. Kruth, Processing AlSi10Mg by selective laser melting: parameter optimisation and material characterization, University of Leuven, Department of Mechanical Engineering, Leuven, Belgium, Materials Science and Technology (2015) 918-923. [4] A. Townsend, N. Senin, L. Blunt, R.K. Leach, J.S. Taylor, Surface texture metrology for metal additive manufacturing: a review, Manufacturing Metrology Team, Faculty of Engineering, University of Nottingham, UK, Precision Engineering 46 (2016) 34–47. [5] C. K. Stimpson, J. C. Snyder and K. A. Thole, roughness effects on flow and heat transfer for additively manufactured channels, Department of Mechanical and Nuclear Engineering the Pennsylvania State University, PA, USA, Proceedings of ASME Turbo Expo 2015: Turbine Technical Conference and Exposition, (2015) 1-13. [6] F. Calignano & D. Manfredi & E. P. Ambrosio & L. Iuliano & P. Fino, Influence of process parameters on surface roughness of aluminum parts produced by DMLS, Instituto Italiano di Tecnologia, Corso Trento, 21, 408 (2016) 1-9. [7] B. Liu, R. Wildman, C. Tuck, I. Ashcroft, R. Hague, investigation the effect of particle size distribution on processing parameters optimization in selective laser melting process, Additive Manufacturing Research Group, Loughborough University, (2011) 227-238. Poster number : P09 153

A new focus variation apparatus for multiscale topographical surface analysis, application to High Entropy Alloys cladding.

Authors : Anaïs GALLIERE1, Hervé MORVAN1, Jean-François TRELCAT2, Laurent BOILET2, Emmanuel PARIS3, Mirentxu DUBAR1, Maxence BIGERELLE1 1 : LAMIH, Campus Mont Houy, 59300 Aulnoy lez Valenciennes, France 2 : CRIBC, Av. du Gouverneur E. Cornez 4, 7000 Mons, Belgique 3 : Nano Surface Division, 7 rue de la croix Martre, 91120 Palaiseaux, France

A new focus variation microscope is in development with BrukerTM (San Jose, USA). This measuring instrument allows us to measure in our project a very rough surfaces (around 300µm for vertical scale) with very little and huge scales identification (from 0.3 µm to 2 mm lateral scale without any problem). It is a new way of thinking and an evolutional way of measuring. To improve tribological properties, from all known methods, coatings are increasingly popular. Lots of coatings exist, they are characterized by process and chemical elements. Four types of coatings are commonly used for their good wear resistance: electrolysis Hard Chrome, CVD Boron Nitride, CVD Diamond and CVD W/WC. The roughness of the surface area is linked to the process used and their inherent parameters. The surface topography has to be optimised in order to obtain given surface features. In this paper, we will focus on a new type of coating among all the existing treatments. High Entropy Alloys are famous for their hardness. For the first time a process has been adapted to be used as coating. They present the specialty to don’t form precipitate during the cooling and to not introduce local mechanical heterogeneity on the coating. Also, it is eco-friendlier than the Hard Chrome. To apply this coating, a laser cladding process is used on a mixed powder consisted of 5 metal elements with equimolar ratios. Topological properties obtained on these claddings will be investigated to optimize wanted features. It creates a multi-scale topography from under- powder size (incomplete or complete powder melting) to upper powder size (process conditions). It shows that different pre-melting zones interactions will be analysed. This new focus variation allows to well detect these micro topographies. Statistical analysis (covariance) allows to highlight the different process cladding scales.

Figures: Topography of HEA coating samples 154 155 Abstract submitted to the www.metprops2019.org conference Poster number : P10

Experimental validation of surface specific test artefacts fabricated using fused deposition modelling in a real industrial application

Email: [email protected]

Keywords: Additive manufacturing, Fused deposition modelling, Surface metrology and characterization, ANOVA, Power spectral density, Areal surface texture parameters and Stripe projection technique.

Abstract: Fused Deposition Modelling (FDM) is a well-established extrusion based Additive Manufacturing (AM) technology that produces components in layers by deposition of materials. It has found its uses in various industrial and medical applications but mainly adopted as a functional prototype. This is mainly due to the degraded dimensional control and surface quality of the fabricated parts [1, 2]. FDM parts have a great potential in industrial acceptance provided it meets the standards set by conventional manufacturing. Therefore, it is necessary to understand the surface behaviour in relation to the factors affecting it. This paper addresses the effects of various print settings, geometrical design variations and build-platform orientation on the surface. It also identifies a new “step” artefact for studying the flat surfaces and uses the already established knowledge on inclined surfaces by the use of truncheon artefact [3] to produce complete information about the print settings – surfaces relationship. Most importantly, areal surface parameters [4] and advanced characterization methods are employed for defining the surface. The artefacts were printed using Polylactic acid (PLA) material. Figure 1 shows the CAD model of the truncheon artefact with varying build inclination from 0° to 40° in steps of 10° and the step artefact has 4 steps with varying height (2, 4, 8, 16mm). The printed samples were then measured using a stripe projection optical microscope and all the surfaces captured were levelled using the least squares plane. The initial results have shown that the raster pattern on the flat surfaces is set to be affected by infill density, build-platform orientation and layer thickness whereas, the inclined surfaces are mainly affected by layer thickness (see figure 2). Finally, the results of this study are formed into guidelines for manufacturing and verified by building a TylöHelo AB company’s product. Further, this paper can be enhanced by including the surface measurements from various other microscopes and analyse the effectiveness of each instrument and to validate the study.

1 156 Abstract submitted to the www.metprops2019.org conference

Figure 1. CAD model of the surface specific test artefacts (a) Truncheon (b) Step.

Figure 2. (a) The 3D view of surface images depicting the effect of build-platform orientation and infill density (b) Influence of layer thickness on average roughness parameter.

Table 1. Results from ANOVA depicting the most significant surface roughness parameters and influence of print settings on respective areal surface texture parameters

P value 3D Description Adj. R² Sig. F Build Layer Top Infill Hexagonal Triangle parameters Height Orientation Thickness Layer Density infill infill Arithmetic Mean Sa 44% 2.7E-16 0.01 1.4E-16 0.47 1.9E-06 0.73 0.49 0.68 Height Inverse Areal Smc 45% 1.2E-16 0.02 4.1E-17 0.57 1.7E-06 0.39 0.63 0.64 Material Ratio

Vv (p = 10%) Total Void Volume 45% 1.8E-16 0.02 6.9E-17 0.57 1.6E-06 0.39 0.63 0.64

Vmc (p = 10%, Core Material 49% 1.8E-18 0.02 3.7E-19 0.48 9.6E-07 0.82 0.59 0.67 q = 80%) Volume Vvc (p = 10%, Core Void Volume 45% 9.3E-17 0.04 1.5E-17 0.61 3.4E-06 0.35 0.74 0.65 q = 80%) Core Roughness Sk 51% 9.8E-20 0.02 2.1E-20 0.68 4.9E-07 0.85 0.83 0.51 Depth

Main References [1] Gibson I, Rosen DW, Stucker B, Additive manufacturing technologies, Springer, New York. 2010, https://dx.doi.org/10.1007/978-1-4419-1120-9. [2] Reddy, V., Flys, O., Chaparala, A., Berrimi, C., V, A. and Rosen, B. (2018). Study on surface texture of Fused Deposition Modeling. [3] D. Ahn, J.-H. Kweon, S. Kwon, J. Song, and S. Lee, Representation of surface roughness in fused deposition modeling, Journal of Materials Processing Technology, vol. 209, 2009, pp. 5593-5600, ISSN 0924-0136, https://doi.org/10.1016/j.jmatprotec.2009.05.016. [4] R. Leach, Characterisation of Areal Surface Texture. Heidelberg: Springer, 2013.

2 157 Poster number : P11

Bio-Inspired 4-D Printing Strategies For Control of Structural Damage in Tribological Applications H. A. Abdel-Aal1*, M. El Mansori2, Drexel university, [email protected] Ecole nationale supérieure d’arts et métiers, france

Additive manufacturing (3-D and 4-D printing) offer feasible pathways to realize composite smart surface systems. These are a class of constructs of which surface and subsurface micro-structure are tailored to control the evolution of friction-induced surface and subsurface damage. Manifestation of this class of systems on an industrial scale depends on developing a strategy for printing that realizes the required properties of surface and subsurface layers. This, in turn, hinges on undersatnding the interaction between subsurface material properties (stiffness and strength), behavior at the surface roughness level, and the layer-by-layer property-gradient requirements. Such an understanding is a current bottleneck in the technological world. To that effect, a strategy that capitalizes on the potential of 3-and-4 dimensional printing, polymeric or metallic, does not exist. This deficiency has its origins in the focus on texturization of the surface layer without considering the interaction with subsurface layering and its role in preserving the structural integrity of the component. The biological world, particularly within the so-called legless reptiles, the intricate interaction between deterministic textures and subsurface layering of ventral skin is advanced and well understood. It offers a unique opportunity to develop advanced 4-D printing paradigms that capitalize the potential of metal printing. Friction performance and control in legless-reptiles are functions of two intertwined factors. The first is the optimized interplay between the elements of surface roughness (micro-ornamentation) and energy dissipation resulting from muscular control. The second, is the damage containment ability of the fiber-matrix cluster within the skin of the reptile. The skin of a reptile manifests composite structure of keratin fibers embedded in an elastin matrix. Curious within this composition, is that fiber density, matrix size, orientation of fibers, and mechanical properties of that structure comprising the skin are layered in accordance with functional requirements and tribological constraints of the immediate surroundings. This work has two purposes. First, to explore the relationship between surface, and subsurface, structure of reptilian skin in relation to tribological performance. Secondly, to develop a generic, but holistic, strategy for manifesting deterministic surface-systems that capitalize on the layer-by-layer property customization in reptiles suitable for advanced metallic printing techniques. 158 Abstract submitted to the www.metprops2019.org conference

Poster number : P12 VR-technique as support to manual polishing

S Rebeggiani1, B-G Rosén1, L. Baath1,2 1Halmstad University, The Functional Surfaces Research Group, Sweden, 2QSO Interferometer Systems AB, Halmstad, Sweden

E-mail: [email protected]

Keywords: surface metrology, abrasive polishing, VR, Coherent Wave Scatter system

Abstract Manual polishing is still common in industry today even though automated processes are desirable for many reasons. Vibrating hand tools and monotonic work positions increase the risk of occupational injuries [1], and the work is time-consuming and non-attractive to next-coming generations. Therefore, the question of how to replace manual polishing techniques with automated ones is highly relevant, see e.g. [2] developing human-robot solutions for finishing operations. The focus in this work has been on how surface metrology can assist manual polishers to optimize the polishing strategies in order to translate human interpretation into numbers, which is expected to facilitate more automated processes where the need for standardised surface criteria is even higher.

The study is based on a two samples prepared by a manual polisher with long experience within the field. The samples were in the size of 100x100x20 mm, produced by via powder metallurgy (HRC 55), and initial surfaces were milled and ground. The polisher was chosen preparation techniques for the different steps himself, see table 1, but was told to achieve a final surface quality corresponding to the ones for injection moulding of shiny plastic components using abrasive polishing techniques. The samples were measured between every step with a Coherent Wave Scatter system (CWS) [3], a surface measurement technique where the entire surface can be measured, and then overlaid on the measuring object. Forces induced to the samples and applied patterns (tool paths) have been documented continuously during all steps via a type of force plate originally developed at Volvo Technology.

Focus was on how surface metrology, in this case mainly the parameter Rq(CWS) (equivalent to the RMS surface roughness), could add valuable data regarding local surface conditions and thereby support the polisher with information useful to decide on next-coming steps. E.g. variations on initial surface qualities, invisible for the naked eye due to gradual changes, in combination with material properties tell what tool combinations that should be used and at what levels (like time and force). Similarly, diamond paste can be applied with precision when metrology data is overlaid on the workpiece itself, and so the polisher minimize the risk to ‘over-polish’ and worsen the surface quality (see fig. 1).

1 159 Abstract submitted to the www.metprops2019.org conference

Accepted areas might otherwise be further polished when perceived surface appearance are worse than the ‘real’ measured ones.

Figure 1. Upper left, CWS measurement of sample C step 9 (represented by the Rq(CWS) parameter); upper right, application of paste with metrology data projected on the sample; lower left, application of the paste; lower right, CWS measurement of sample C step 10 (represented by the Rq(CWS) parameter).

Table 1. Overview of applied preparation techniques.

SampleB: Step Technique Pad material Abrasive size [um] Time [min] 3 Hand tool fibre 8 6,3 3_2 Hand tool fibre 8 8,0 4 Hand tool felt 3 2,2 4_2 Manually felt 3 1,0 5 Hand tool felt 3 3,8 6 Manually felt 3 6,8

2 160 Abstract submitted to the www.metprops2019.org conference

7 Hand tool felt 3 2,0 8 Manually felt 3 3,8 SampleC: Step 3 Hand tool fibre 8 11,0 4 Hand tool fibre 3 8,3 5 Hand tool felt 3 3,0 6 Manually felt 3 1,5 7 Hand tool felt 3 6,5 8 Manually felt 3 5,7 9 Hand tool fibre 15 8,0 10 Hand tool fibre 15 1,8 10_2 Hand tool fibre 15 3,4 10_3 Hand tool fibre 15 2,6 10_4 Hand tool fibre 15 5,1 11 Hand tool fibre 8 5,8 11_2 Hand tool fibre 8 3,7 12 Hand tool fibre 3 8,0 13 Hand tool felt 3 7,5 14 Hand tool felt 3 3,0 14_2 Hand tool felt 3 4,0 15 Manually felt 3 4,7 15_2 Manually cotton 3 1,7

Main References [1] RISE. Available from: www.swerea.se/nollvibrationsskador. [Accessed 19/01/30] [2] SYMPLEXITY website. Available from: www.symplexity.eu/ [Accessed 18/12/18] [3] QSO Interferometer Systems AB. Available from: qisab.com/products- solutions/products/cws640/. [Accessed 19/01/28]

3 161 Abstract submitted to the www.metprops2019.org conference

Poster number : P13 Using Confocal Fusion for measurement of metal AM surface texture

O Flys1,2, J Berglund1,3, B-G Rosen2 1RISE Research Institutes of Sweden, 2Halmstad University, Functional Surfaces Research Group, 3Department of Industrial and Materials Science, Chalmers University of Technology

E-mail: [email protected]

Keywords: additive manufacturing, surface topography, Powder Bed Fusion, Confocal Fusion, Coherence Scanning Microscopy, Confocal Microscopy.

Abstract Additive manufacturing (AM) in metal is growing rapidly in several industrial sectors. The main advantage of AM is that it allows flexibility in design of complex geometries, internal features and lattice structured objects. However, despite progress in material development and mechanical performance of manufactured parts, the surface topography is still presenting limitations for using parts made by Powder Bed Fusion using Laser Beam Melting (PBF-LBM) process without post-processing. To address this issue effectively more comprehensive quality assurance regarding measurement, analysis and characterization of surface topography for PBF-LBM manufactured parts needs to be developed [1–3]. The highly complex nature of as printed metal AM surfaces pose other challenges for making measurements compared to surfaces made with many conventional processing methods. The high complexity is caused by high aspect ratios, mix of high and low reflexivity, steep angles etc, see figure 1 for an example. It is not clear which method is the most suitable for measuring these surfaces [4]. The objective in this study was to compare three different measurement modes available in one instrument to evaluate advantages and drawbacks of the respective techniques regarding measurements of metal AM surfaces. The evaluated measurement modes are Confocal Microscopy [5], Coherence Scanning Interferometry [5] and Confocal Fusion [6,7].

The method employed in the presented research work is to apply a calibration procedure that include several artefacts to depict strong and weak sides of the studied techniques. Additionally, the effect of advantages and drawbacks of evaluation was tested on typical surfaces produced by PBF-LBM process. Surfaces printed at 0⁰ and 90⁰ inclination were compared regarding the measurement results achieved from the different methods. Besides comparison of areal measurements acquired by different modes available in the instrument also extracted profile measurements were compared with profile images acquired using alternative optical techniques such as Scanning Electron Microscope (SEM) or Optical Microscope. Results of the profile comparisons help to illustrate features that can be depicted by surface measurements, applying

1 162 Abstract submitted to the www.metprops2019.org conference

different measurement principles, as well as enables comparison of raw profile data between different types of measurements.

Figure 1. Example of metal AM surface with high complexity [3].

Main References [1] A. Townsend, N. Senin, L. Blunt, R.K. Leach, J.S. Taylor, Surface texture metrology for metal additive manufacturing: a review, Precis. Eng. 46 (2016) 34–47. doi:10.1016/j.precisioneng.2016.06.001. [2] A. Triantaphyllou, C.L. Giusca, G.D. Macaulay, F. Roerig, M. Hoebel, R.K. Leach, B. Tomita, K.A. Milne, Surface texture measurement for additive manufacturing, Surf. Topogr. Metrol. Prop. 3 (2015) 024002. doi:10.1088/2051-672X/3/2/024002. [3] J. Berglund, R. Söderberg, K. Wärmefjord, Industrial needs and available techniques for geometry assurance for metal AM parts with small scale features and rough surfaces, Procedia CIRP. 75 (2018) 131–136. doi:10.1016/j.procir.2018.04.075. [4] A. Thompson, N. Senin, C. Giusca, R. Leach, Topography of selectively laser melted surfaces: A comparison of different measurement methods, CIRP Ann. - Manuf. Technol. 66 (2017) 543–546. doi:10.1016/j.cirp.2017.04.075. [5] R. Leach, ed., Optical Measurement of Surface Topography, Springer-Verlag, Berlin Heidelberg, 2011. //www.springer.com/la/book/9783642120114 (accessed November 29, 2018). [6] A. Matilla, J. Mariné, J. Pérez, C. Cadevall, R. Artigas, Three-dimensional measurements with a novel technique combination of confocal and focus variation with a simultaneous scan, in: Opt. Micro- Nanometrology VI, International Society for Optics and Photonics, 2016. doi:10.1117/12.2227054. [7] C. Bermudez, A. Matilla, A. Aguerri, Confocal fusion: towards the universal optical 3D metrology technology, in: euspen, Cranfield University Campus, Bedfordshire, UK, n.d.

2 163 Abstract submitted to the www.metprops2019.org conference

Poster number : P14

The influence and correction of cone-beam artifacts on surface texture data computed from surfaces extracted from CT scans of additively manufactured parts.

A Townsend1, J Cuadra2, K Champley2, Harry Martz2, Liam Blunt1 1The Centre for Precision Technologies, University of Huddersfield, West Yorkshire, HD1 3DH UK. 2Nondestructive Characterization Institute, Lawrence Livermore National Laboratory, Livermore, CA, 94550 USA

E-mail: [email protected]

Keywords: X-ray computed tomography, additive manufacturing, cone-beam artifacts, error corrections

Abstract Surface texture data generation from X-ray computed tomography (CT) scans of additively manufactured (AM) parts is important for verification and analysis of performance in functional applications such as bio-attachment, fluid flow, heat transfer and coating adhesion. These analyses require quantitative results with the associated areal surface texture parameter values per ISO Standard 25178-2 derived. ISO Standard values have now been generated from surfaces extracted from CT measurements of metal powder bed fusion AM parts, with values of areal surface roughness (Sa) less than 0.5% different from reference (focus variation) measurements1. Most commercially available X-ray CT systems are of cone-beam configuration. One drawback of cone-beam CT systems, however, is that as the X-ray cone-beam angle increases reconstruction errors increase as a function of cone angle. Specifically, these errors occur in areas above and below the midplane of the CT system, resulting in a progressively more significant effect on the extracted surface data toward the top and bottom of the measurement volume. This paper reports on the results of an investigation into the errors introduced on extracted surface texture data as the scanned surface is positioned at locations within the measurement volume with progressively increasing cone-beam angles. The results from three cone-beam CT systems will be compared to results from a synchrotron CT system, the latter with a nominally parallel X-ray beam, which, therefore does not produce cone-beam artifacts. The use of iterative reconstruction algorithms to reduce cone-beam artifacts will be demonstrated. Corrections applied to the CT projections for X-ray scatter and beam hardening will also be discussed.

Main References [1] Townsend A, Racasan R, Leach RK, Senin N, Thompson A, Ramsey A, Bate D, Woolliams P, Brown S, Blunt L. An interlaboratory comparison of X-ray computed tomography measurement for texture and dimensional characterisation of additively manufactured parts, Additive Manufacturing, Volume 23, 2018, Pages 422-432, ISSN 2214-8604. https://doi.org/10.1016/j.addma.2018.08.013.

1 164 Abstract submitted to the www.metprops2019.org conference

Poster number : P15 Multiscale machinability of natural fiber composites: From surface fingerprint to cutting mechanisms

F Chegdani1, M El Mansori1,2 1Arts et Métiers ParisTech, MSMP Laboratory / EA7350, Rue Saint Dominique, 51006, Châlons-en-Champagne, France. 2Texas Engineering Experiment Station, 3131 TAMU, College Station, Texas, USA.

E-mail: [email protected]

Keywords: Natural fiber composites (NFC), Machining, Surface fingerprint, Cutting mechanisms.

Abstract Machining processes by material removal of natural fiber composites (NFC) is function and scale dependent. These are due to the multiscale complex structure of the natural fibrous reinforcement within the overall composite structure. This multiscale complex structure of natural fibers induces specific physical cutting mechanisms at each characteristic scale of the natural fibrous structure. During the machining stage we need to consider the cutting process and all the individual elements of the process that contribute to the machined surface “finger-print”. In addition, consideration would need to be given to cutting mechanisms, which relate to specific features of the material removal process and the relative spatial scale of these futures. This will require an interdisciplinary approach to understand the machined surface “fingerprint” thorough understanding the manner in which the whole surface has been produced. In this paper the machinability characteristics of NFC are studied for different cutting processes (milling, drilling, orthogonal cutting) and different natural fibrous structures (short fibers, unidirectional long fibers, bidirectional long fibers) reinforced in a similar polypropylene matrix. This study is performed using a multiscale approach based on the wavelet transform decomposition for the topographic signals of machined surfaces in addition to microscopic observations of these surfaces using scanning electron microscope (SEM). The aim of this study is to highlight, at each feature scale of the natural fibrous structure, how the cutting mechanisms occurred and how they contribute to the machined surface “fingerprint” at a given considered scale.

1 165 Abstract submitted to the www.metprops2019.org conference

Poster number : P16 Surface roughness studies of magneto-electrodeposited CoFe2O4 thin films and its effect on the fabrication of transmission lines

N. Labchir1,2*, A. Hannour1, D. Vincent2, A. Ihlal1, and M.Sajieddine3

1Laboratory of Materials and Renewable Energies, Faculty of Sciences Agadir, BP 8106, Cité Dakhla, 80000 Agadir, Morocco. 2Laboratory of Hubert Curien UMR CNRS, 42000 Saint-Etienne, French. 3Laboratory of Physics of Materials, University of Sultan Moulay Slimane, FST, BP 523, 23000 Béni Mellal, Morocco.

E-mail: [email protected]

Keywords: cobalt ferrite, roughness surface, magnetic field, thin films, electro- deposition.

For half a century, nanotechnologies have covered a large number of technological fields whose common denominator is the nanometric size of structures. This is a major theme of research for both basic sciences and applications, relying heavily on the development of nanomaterials [1]. Thanks to their original properties, nanomaterials allow innovations in various fields. Indeed, there is a wide range of potential uses of nanomaterials in different forms and for various physical, chemical, pharmaceutical and cosmetic applications. Their development also makes it possible to achieve a significant gain in productivity and to open new perspectives by accessing innovative technology. In this work, we are particularly interested in nanomaterials in the form of thin layers of cobalt ferrite and their physical and chemical characterizations by XRD, SEM (EDX), AFM, and SQUID. Thin films are prepared by magneto- electro-deposition by applying an electrical potential that reduces the iron and cobalt ions on the FTO substrate [2]. The AFM results show that the magnetic field modifies the surface roughness and profiles of the elaborate thin layers. Cobalt ferrite already has many fields of application, because of their original magnetic properties, their low cost of production, compared to better known magnetic materials based on precious metals. The most common applications are ferrofluids, and magnetic recording and use as a massive component for power and permeability applications. This is directly related to the reduction in size of magnetic materials, which leads to a modification of their properties, such as the appearance of superparamagnetism of nanoparticles, or perpendicular spontaneous magnetization with very thin layers. In conclusion, this material is an interesting candidate for the manufacture of transmission lines [3]. Coplanar lines have been designed, modeled and simulated using the HFSS software. Following interesting simulation results; a first prototype has been manufactured, it remains liable in the future to characterize it at high frequencies by the vector network analyzer VNA.

1 166 Abstract submitted to the www.metprops2019.org conference

Figure 1. AFM image of CoFe2O4 thin film electrodeposited with presence of magnetic field.

Figure 2. Coplanar waveguide engraved on cobalt ferrite thin film.

Main References

[1] C. N. R. Rao and A. K. Cheetham, J. Mater. Chem 2001, 11, pp 2887–2894. [2] S. Olvera , E.M. Arce Estrada, J. Sanchez-Marcos, F.J. Palomares, L. Vazquez, P. Herrasti , J. Materials Characterization, 2015,105, pp 136–143. [3] Monika Sharma, Bijoy K. Kuanr, Manish Sharma, and Ananjan Basu, International Journal of Materials, Mechanics and Manufacturing, 2014 , 2, p 1.

2 167 Abstract submitted to the www.metprops2019.org conference

Poster number : P17

Characterisation of the surface topography evolution of an ink-jet printed transparent fluoroplastic with coherence scanning interferometry

Carlos Gomez1, Carlo Campanelli2, Rong Su1, Simon Lawes1, Richard Leach1 1University of Nottingham, Manufacturing Metrology Team, 2University of Nottingham, Centre for Additive Manufacturing

E-mail: [email protected]

Keywords: Surface metrology, coherence scanning interferometry, additive manufacturing, ink-jet printing, transparent film, fluoroplastic

Abstract: We present the results of an empirical investigation into the evolution of the morphology of an ink-jet printed transparent polymer using coherence scanning interferometry (CSI). CSI is a high precision optical surface measuring technique, which has been selected for this application since it can perform relatively fast (compared to contact methods) non-contact areal surface topography measurement of transparent parts [1]. Transparent thin films can be challenging to measure with optical surface measuring techniques, given that film effects can distort the measurement of the top surface topography [2]. In CSI, a transparent film will generally produce an additional signal from the substrate, which can be well separated if the film is sufficiently thick. However, when the film thickness is less than a micrometre, signals from the surface and substrate may merge, therefore, making their separation a more complex task [2,3]. The investigated features on the printed parts can range from a few nanometres to tens of micrometres in height, and from tens of micrometres to a few millimetres in wavelength. Some features present high slope angles that meet or even surpass the numerical aperture limitation of the employed objective lenses. We demonstrate the ability of CSI to characterise these challenging features in terms of data coverage, surface topography repeatability, measurement time and area. The measurements include the use of a combination of measurement parameters and the use of advanced functions, such as signal oversampling [4] and film analysis. There is currently a lack of knowledge regarding how some polymers, in this case THV 221 [5,6], can be ink-jet printed and an analysis of the areal surface topography measured by CSI can provide a better understanding of the features and characteristic textures that result from the ink-jet printing process. Most THV applications include multilayer parts, where a thin layer can be used as a protective coating or to provide enhanced barrier properties to other layers [6,7]. This investigation also provides an insight in to how to control and optimise the quality of THV 221 printed parts. Relevant printing parameters, including number of layers, THV concentration and drop separation, have been selected and varied to produce the samples used for the experimental work. A variety of basic geometries, such as dots, lines and films have been considered.

1 168 Abstract submitted to the www.metprops2019.org conference

Figure 1. CSI measurements of ink-jet printed fluoroplastic THV 221 geometries, each example corresponding to 10 weight percent lines formed by a) a single layer, b) three layers, and 20 weight percent honeycombs (hexagonal lattices) formed by c) a single layer, d) three layers.

Main References [1] de Groot, P. (2015). Principles of interference microscopy for the measurement of surface topography, Adv. Opt. Photon., 7, 1, pp 1-65. [2] Fay, M., Dresel, T. (2017). Applications of model-based transparent surface films analysis using coherence-scanning interferometry, Opt. Eng., 56, 11, 111709. [3] Colonna de Lega, X., de Groot, P. (2008). Transparent film profiling and analysis by interference microscopy. Proc. SPIE 7064, 70640I. [4] Gomez, C., Su, R., Thompson, A., DiSciacca, J., Lawes, S., Leach, R. K. (2017). Optimization of surface measurement for metal additive manufacturing using coherence scanning interferometry, Opt. Eng., 56, 11, 111714. [5] Ok, S., Sadaf, S., Walder, L. (2014). Basic characterization and investigation of a fluorinated terpolymer in pure state and in mixtures with kaolinite at solid interphases of thin films prepared by facile solution cast and nonsolvent methods, High Performance Polymers, 26, 7, pp 779–789. [6] Smith, D., Iacono, S., Iyer, S. (2014). Handbook of fluoropolymer science and technology. John Wiley & Sons. [7] Wiley-VCH (2016). Ullmann’s polymers and plastics: products and processes. Wiley.

2 169 Abstract submitted to the www.metprops2019.org conference

Poster number : P18 Lead detection based on thread method simulation

B Barwick, A Karatas, M Eifler, J Seewig Technical University Kaiserslautern

E-mail: [email protected]

Keywords: micro lead detection, macro lead detection, thread method, simulation

Abstract (Intro-Background) Lead detection on shafts sealing surfaces is a common task in mechanical engineering. Considering operation environments with zero leakage requirements like food or printing industry, a reliable method for lead identification and classification is needed. Modern algorithms for lead evaluation focus on the estimation of main lead angle and its deviation from the circumferential direction. For the estimation of sealing behavior, also vertical information like valley depth and peak height of the main lead structure have to be taken into account. The seal might be tight even though the surface features structures with high lead angles but low vertical extend and vice versa. For macro lead there is a system for the classification of acceptable vertical extend in different lead angles [1]. It is challenging to establish such a system for micro lead, since what is perceived as micro lead today can be traced back to several reasons like setting lead or even transport damage. This paper proposes a method of lead measurement based on the simulation of the thread method to characterize lead of any kind. For the application of this method no distinction between macro and micro lead is required. The thread method dates back to the early days of lead evaluation when computer aided evaluation was not well-established. For this method a thin thread or fiber is spun around the shaft’s sealing surface and a weight is attached to it. If the thread moves axially along the rotating shaft, it indicates lead on the sealing surface. The thread behavior in the experiment serves as a good and repeatable estimate for the seal’s operational behavior since the mechanical interaction in both cases is similar. Therefore, a simulation model that reproduces this mechanical interaction on the sealing surface can serve as a predictor for a shaft’s sealing behavior in operation. For the simulation the comparably soft thread surface is modelled as a grid of linked spring and damper elements, which interact with the solid surface of the shaft. This modeling principle is commonly used for the analysis of visco-elastic friction between elastomer materials and solid surfaces. The simulation can be applied both to generic and measured surface topographies (measured with either tactile or optical measurement equipment). It is also possible to simulate on small measurement fields and – assuming homogenous surface across the circumference – extrapolated to the whole shaft, thus allowing faster data acquisition and processing.

1 170 Abstract submitted to the www.metprops2019.org conference

Overall the approach can serve as a universal, fast and repeatable estimator for sealing surface behavior which is expected to have a high acceptance by users familiar to the original experimental approach.’

Main References [1] Seewig J, Hercke T (2009) 2nd Generation Lead Measurement (Lisbon, Portugal: XIX IMEKO World Congress Fundamental and Applied Metrology)

2 171 Abstract submitted to the www.metprops2019.org conference Poster number : P19

Questioning the approach to predict the evolution of tire/road friction with traffic from road surface texture

M-T Do1, V Cerezo1, C Ropert1 1 IFSTTAR, AME-EASE, 44344 Bouguenais, France

E-mail: [email protected]

Keywords: Polishing; SEM images; Damage; Texture

Abstract: It has been assumed that, under traffic actions, the bitumen layer of an asphalt concrete is progressively removed and, after a few months, no bitumen remains on the road surface and the aggregates are polished by repeated passes of the car tires. This assumption helps to explain the evolution of the tire/road friction with the traffic (Fig. 1) and establishes the basis following which the decrease of the tire/road friction (decreasing part of the graph in Fig. 1) can be explained solely by that of the aggregates’ characteristics. Results have shown that this statement is not always true [2]. There is then a need to better understand the evolution of the surface properties of asphalt concretes subjected to traffic.

In this study, examination of the surface of an asphalt concrete during a polishing process is made by means of SEM (scanning electron microscope) images. It reveals that the bitumen layer is actually a mix of bitumen and fine particles; analysis of the chemical composition is performed to determine the origin of the fine particles. During the polishing process, there is a reduction of the bitumen layer’s thickness due to various damage mechanisms (cracking, raveling) (Fig. 2). The reduction is uneven and depends on the surface topography. The presence of the bitumen layer can still be observed even at an advanced polishing stage and, furthermore, its composition can evolve from a layer- to a granular-like nature. Profiles are measured on the bitumen layers (using an Alicona Infinite Focus sensor) and it was observed that the variation of shape parameters such as the root-mean-square slope or the summit curvature can be erratic; results depend obviously on the chosen measurement areas.

In the light of the obtained results, it seems clear that current approaches to predict friction from aggregates’ characteristics should be questioned. Research is ongoing to determine on the one hand relevant parameters to characterize the damage of the bitumen layer and, on the other hand, to describe the evolution of road surface texture with traffic from bitumen’s and aggregates’ characteristics and relate it to friction.

1 172 Abstract submitted to the www.metprops2019.org conference

0,60

0,50

Friction coefficient 0,40

0,30 0 50000 100000 150000 200000 Number of passes

Figure 1. Evolution of the tire/road friction with the traffic (simulation in laboratory using the Wehner/Schulze machine [1])

Epoxy used for SEM observations

Bitumen layer Cracks

Aggregate

Figure 2. Cracking of the bitumen layer due to polishing actions

Main References [1] M-T Do, Z Tang, M Kane, F de Larrard, Pavement Polishing – Development of a Dedicated Laboratory Test and its Correlation with Road Results, Wear (2007) 263, 36-42. [2] A Nataadmadja, M-T. Do, D Wilson, S Costello, Quantifying aggregate microtexture with respect to wear – Case of New Zealand aggregates, Wear (2015) 332-333, 907-917.

2 173 Abstract submitted to the www.metprops2019.org conference Poster number : P20

Traceology for prediction of polishing roses

S Rebeggiani1, B-G Rosen1, Z Dimkovski1 1Halmstad University, The Functional Surfaces Research Group, Sweden

E-mail: [email protected]

Keywords: polymer coating, surface evaluation, scratch pattern, end-of-line repair

Abstract The surface finish of vehicles plays a major role on perceived product quality. To achieve a homogeneous and defect free surface finish, most car and truck bodies undergo end-of-line repairs, i.e. local abrasive polishing, to eliminate spot defects. However, other types of defects can occur during the repair if the surface is improperly polished. One of those defects are ‘polishing roses’ or ‘holograms’, described as clusters of shallow micro scratches, which under certain lightening conditions create a three dimensional appearance, i.e. it moves when viewed from different angles similar to a hologram [1][2]. Some aggravating circumstances are that these defects are hard to detect without directed sun light, which is not so easy to mimic in the production environment, and that the cleaning procedure is highly relevant since wax included in many polishing agents tend to fill up any remaining scratches which lead to visually perceived ‘perfect’ surfaces [3]. [2] have used a goniophotometer for reflectance measurements to evaluate the surface finish of polished samples, and [4] have used Ra (arithmetic mean value) and the Gaussian distribution of S (mean spacing of local peaks), both based on WLI measurements.

In this study, repaired samples, with and without polishing roses, were analysed based on interferometer measurements to study scratch patterns, i.e. traceology [5], in detail to better understand the difference between accepted and non- accepted structures. Figure 1 shows WLI measurements (phase-shifting mode, 20x objective with a measurement area of 0.3x0.4 mm, quoted vertical resolution of 0.1 nm and a sampling interval of ~1 μm) on two different sample surfaces, one considered to be ok, the other not. A previously developed method for scratch analysis, successfully used to study the quality of cylinder liner surfaces [6], has been further improved to study the occurrence of scratches, and their width and depth. The goal is to link characteristic scratch patterns perceived as polishing roses to the process parameters generating them, i.e. to find key parameters for successful repairs, which also would lead to an objective way to assess surface quality in lab environments.

Other characterisation methods will also be investigated to find the most suitable for prediction of polishing roses.

1 174 Abstract submitted to the www.metprops2019.org conference

Figure 1. Left; sample K2 with a so called ‘polishing rose’. The WLI measurements are taken between the blue tape strips within the red rectangle. Mid; WLI measurements within area K2, i.e. the red rectangle in the left figure. Right; WLI measurements within area R1 – acceptable surface quality. Both WLI measurements are images created by MountainsMap® [7].

Main References

[1] Autopia Car Care. Available from: www.autopia.org/forums/the-detail-institute-presented-by- autopia-carcare-com/36769-detail-institute-paint-defects.html [Accessed 18/12/18] [2] Jenkins J M and Kane K M (1998) Evaluation of Finesse/Polish of Automotive Clearcoats. SAE Technical Paper Series, 980978 [3] Scholl Concepts GmbH. Available from: www.schollconcepts.com/en/shop/uncategorized/faq [Accessed 18/12/07] [4] Kubo T et al (2010) Evaluation of polished surface for viscoelastic polymer. Advanced Materials Research. 126-128 pp 493-498 [5] Thomas TR et al (2011) Traceology, quantifying finishing machining and function: A tool and wear mark characterisation study. Wear 271 (3-4), pp 553-558 [6] Dimkovski Z (2011) Surfaces of honed cylinder liners. Doctoral thesis, Chalmers Univ. of Tech. [7] MountainsMap® Premium 7.3.7835, 2018/12/18, Digital Surf. Available from: www.digitalsurf.fr/en/mntkey.html. [Accessed 18/12/18].

2 175 Abstract submitted to the www.metprops2019.org conference Poster number : P21

Multi-scale Topography Analysis of Abrasive Flow Machining (AFM) Finish Surfaces

S Han1, F Salvatore1, J Resh1 1Université de Lyon, ENISE

E-mail: [email protected]

Keywords: abrasive flow machining (AFM), wear mechanism, rubbing, ploughing, cutting, surface topography, surface roughness parameters

Abstract AFM has been shown to be very effective in improving surface roughness of hard-to-reach surfaces, such as internal channels. Their surface roughness improvement can be achieved by material removal, which is done by different interactions between the abrasives and workpiece (e.g., rubbing, ploughing, and cutting). Surface roughness evolution and material removal progress during AFM, as well as SEM micrographs after AFM suggest that different wear mechanism can play a major role in the surfaces created by different AFM media parameters, such as media viscosity, grain size and abrasive concentration. Their subsequent surface integrity, such as residual stress can be different. Therefore, it is necessary to analyse surface topographies, such as abrasion marks, pile-ups, and rolling marks observed in SEM micrographs in terms of surface roughness parameters. In this study, AFM is performed on internal channel surfaces of 15-5PH stainless steel with different media parameters, such as different grit size (54, 150, and 320 grits) and abrasive concentration (35, 50, and 65%). Surface created by AFM with MV65%-150, where straight abrasion marks are clearly seen, is characterized by high Rv value and higher negative skewness, Rsk range. On the other hand, surface finished by AFM with MV50%-54, where frequent pile-ups and rolling marks are observed, is characterized by high Rz and positive skewness, Rsk value. As can be seen, multi-scale surface topography analysis of the AFM finish surfaces with different AFM media is proposed to provide surface roughness parameters to reflect and quantify wear mechanisms occurred in their AFM finish surfaces.

1 176 Abstract submitted to the www.metprops2019.org conference

Initial 10 cycle 25 cycle 50 cycle 100 cycle Media flow 320

- direction Y MV 50% MV X 150

- MV 35% MV 150

- Grain size Grain MV 50% MV Abrasive concentration Abrasive 150

- MV 65% MV 54

- MV 50% MV

Figure 1. Optical micrographs of the pin parts’ surfaces at the interrupted cycles – 10, 25, 50, 75, and 100 cycles - during AFM with different media.

Table 1. AFM test conditions with different AFM media. MV35%-150 stands for AFM media having medium viscosity, 35% abrasive concentration (wt %) and 150 abrasive grit size.

2 177 Abstract submitted to the www.metprops2019.org conference

(a) (b)

Pile-up Media directionflow Media directionflow Pile-up

Pile-up 20 μm 20 μm

Figure 2. SEM micrographs of the pin part surface after AFM for 150 cycles with different media: (a) MV65%-150, (d) MV50%-54, (Magnification: 1500X).

(a) 0.70 0.60

0.50

0.40

0.30 Ra (µm) 0.20

0.10

0.00 MV50 MV35 MV50 MV65 MV50 -320 -150 -150 -150 -54

(b) 3.50 (c) 0.30 0.20 3.00 0.10 2.50 0.00 -0.10 2.00 -0.20 1.50 -0.30 Rv (µm) Rv

Rsk (µm) Rsk -0.40 1.00 -0.50 0.50 -0.60 -0.70 0.00 -0.80 MV50 MV35 MV50 MV65 MV50 MV50 MV35 MV50 MV65 MV50 -320 -150 -150 -150 -54 -320 -150 -150 -150 -54

Figure 3. Average surface roughness parameters perpendicular to AFM flow: (a) Ra, (b) Rv, (c) Rsk. 5 measurements were taken on the surface after AFM with different media.

3 178 Abstract submitted to the www.metprops2019.org conference

Main References [1] Loveless T R, Williams R E, Rajurkar K P (1994) A study of the effects of abrasive-flow finishing on various machined surfaces, Journal of materials processing technology 47 pp133- 151 [2] Kenda J, Pusavec F, Kermouche G, Kopac J (2012) Surface Integrity in Abrasive Flow Machining of Hardened Tool Steel AISI D2, Procedia Engineering, 1st CIRP Conference on Surface Integrity (CSI) 19 pp 172 – 177 [3] Uhlmann E, Roßkamp S (2018) Surface integrity and chip formation in abrasive flow machining, Procedia CIRP 4th CIRP Conference on Surface Integrity (CSI 2018) 71 pp 446-452 [4] Jain R K, Jain V K, Dixit P M (1999) Modeling of material removal and surface roughness in abrasive flow machining process, International Journal of Machine Tools & Manufacture 39 pp 1903-1923 [5] Gorana V K, Jain V K, Lal G K (2006) Forces prediction during material deformation in abrasive flow machining, Wear 260 pp 128-139 [6] Fang L, Zhao J, Sun K, Zheng D, Ma D (2009) Temperature as sensitive monitor for efficiency of work in abrasive flow machining, Wear 266 pp 678-687