DOCSLIB.ORG

The Absorption of Laser Light by Rough Metal Surfaces

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Absorption of Laser Light by Rough Metal Surfaces 2008:08 DOCTORAL T H E SIS The Absorption of Laser Light by Rough Metal Surfaces David Bergström Luleå University of Technology Department of Applied Physics and Mechanical Engineering Division of Manufacturing Systems Engineering 2008:08|: 02-544|: - -- 08⁄08 -- Doctoral Thesis The Absorption of Laser Light by Rough Metal Surfaces David Bergström Division of Manufacturing Systems Engineering Department of Applied Physics and Mechanical Engineering Luleå University of Technology Luleå, Sweden in cooperation with Department of Engineering, Physics and Mathematics Mid Sweden University Östersund, Sweden Luleå, February 2008 Dedicated to the Curious Mind. Cover figure: A laser profilometer image of the topography of a hot rolled stainless steel surface (middle), with a photograph of an experimental setup for absorptance measurements using an integrating sphere (left) and a computer-generated Gaussian random rough surface illustrating the principles of ray-tracing (right). Acknowledgements The work presented in this Doctoral thesis is devoted to the theoretical and experimental study of the light absorption mechanisms in laser processing of rough metals and metallic alloys. The Doctoral thesis consists of a short introduction and a series of six papers, all dealing with different aspects of this topic. This work has been carried out at the Division of Manufacturing Systems Engineering at Luleå University of Technology (LTU) in Luleå, Sweden, and at the Department of Engineering, Physics and Mathematics at Mid Sweden University (MIUN) in Östersund, Sweden, from 2003 to 2008. I would like to express my gratitude to my supervisors Prof. Alexander Kaplan (LTU) and Prof. Torbjörn Carlberg (MIUN) for their advice and support during these past years. My deepest thanks go to Prof. John Powell (Laser Expertise Ltd., Nottingham, UK) for always keeping me focused on the essentials. I’d like to thank him for all the time he has devoted in the discussions of different thoughts and ideas and for proof-reading all my written work. It’s been a pleasure working with you and Alexander and I wish and hope for further collaboration in the future. Thanks are also due to M.Sc. Rickard Olsson and his colleagues at Lasernova AB in Östersund, for once upon a time introducing me to this exciting subject and for their support and friendship. I’m also indebted to Patrik Frihlén of Azpect Photonics AB and M.Sc. Ingemar Eriksson for helping me setting up the equipment for the laser lab in Östersund. Further thanks go to Doc. Mats Tinnsten and Dr. Leon Dahlén for providing the financial circumstances in making this work possible. I would also like to thank my colleagues at my university department in Östersund, especially my fellow PhD student Marianne Olsson for sharing countless cups of coffee over conversations about the trials and tribulations of postgraduate studies as well as of topics beyond. Finally I would like to thank my family for their support and encouragement and my girlfriend Susanne for her love, patience and understanding. Östersund, February 2008 David Bergström i Abstract In Laser Material Processing of metals, an understanding of the fundamental absorption mechanisms plays a vital role in determining the optimum processing parameters and conditions. The absorptance, which is the fraction of the incident laser light which is absorbed, depends on a number of different parameters. These include laser parameters such as intensity, wavelength, polarisation and angle of incidence and material properties such as composition, temperature, surface roughness, oxide layers and contamination. The vast theoretical and experimental knowledge of the absorptance of pure elements with smooth, contamination-free surfaces contrasts with the relatively sparse information on the engineering materials found in real processing applications. In this thesis a thorough investigation of the absorption mechanisms in engineering grade materials has been conducted, both experimentally and theoretically. Integrating sphere reflectometry has been employed to study the impact of surface conditions on Nd:YAG and Nd:YLF laser absorptance of some of the most common ferrous and non-ferrous metallic alloys found in Laser Material Processing. Mathematical modelling and simulations using ray-tracing methods from scattering theory have been used to analyze the influence of surface topography on light absorption. The Doctoral thesis consists of six papers: Paper 1 is a short review of some of the most important mathematical models used in describing the interaction between laser light and a metal surface. Paper 2 is a review of experimental methods available for measuring the absorptance of an opaque solid such as a metal. Papers 3 and 4 are experimental investigations of the absorptance of some of the most frequently found metallic alloys used in Laser Material Processing today. Paper 5 presents results from 2D ray-tracing simulations of random rough metal surfaces in an attempt to investigate the influence of surface roughness on laser scattering and absorption. Paper 6 is a full 3D ray-tracing investigation of the interaction of laser light with a rough metallic surface, where some comparisons also are made to the previous 2D model. ii List of Papers Paper 1 Bergström, D.; Kaplan, A.; Powell, J.: ”Mathematical modelling of laser absorption mechanisms in metals: A review”. Presented at the M4PL16 workshop, Igls, Austria, January 20-24, 2003, Ed: A. Kaplan, published by Luleå TU, Sweden. Paper 2 Bergström, D.; Kaplan, A.; Powell, J.: ”Laser absorption measurements in opaque solids”. Presented at the 10th Nordic Laser Materials Processing (NOLAMP) Conference, Piteå, Sweden, August 17-19, 2005, Ed: A. Kaplan, published by Luleå TU, Sweden. Paper 3 Bergström, D.; Powell, J.; Kaplan, A.: ”The absorptance of steels to Nd:YAG and Nd:YLF laser light at room temperature”. Paper published in Applied Surface Science, Volume 253, Issue 11, pp. 5017-5028, 2007. Paper 4 Bergström, D.; Powell, J.; Kaplan, A.: ”The absorptance of non-ferrous alloys to Nd:YAG and Nd:YLF laser light at room temperature”. Paper published in Applied Optics, Volume 48, Issue 8, pp. 1290-1301, 2007. Paper 5 Bergström, D.; Powell, J.; Kaplan, A.: ”A ray-tracing analysis of the absorption of light by smooth and rough metal surfaces”. Paper published in Journal of Applied Physics, Volume 101, pp. 113504/1-11, 2007. Paper 6 Bergström, D.; Powell, J.; Kaplan, A.: ”The absorption of light by rough metal surfaces - A three-dimensional ray-tracing analysis”. Submitted to Journal of Applied Physics. Shorted version presented at the 26th International Congress on Applications of Lasers and Electro-optics (ICALEO), Orlando, Florida, USA, October 28-November 1, 2007. iii Table of Contents Acknowledgements i Abstract ii List of Papers iii Table of Contents iv Introduction 1 1. Motivation of the thesis 1 2. Methodological approach 1 3. Laser absorption in metals – a short introduction 3 4. Conclusions of the thesis 6 5. Future outlook 7 6. Appendix 9 6.1 Further comparison between 2D and 3D ray-tracing models 9 6.2 AFM characterization and ray-tracing of real engineering grade 13 metal surfaces References 17 Paper 1: Mathematical Modelling of Laser Absorption Mechanisms in 19 Metals: A Review Paper 2: Laser Absorption Measurements in Opaque Solids 49 Paper 3: The Absorptance of Steels to Nd:YLF and Nd:YAG Laser Light 89 Paper 4: The Absorptance of Non-Ferrous Alloys to Nd:YLF and Nd:YAG 117 Laser Light Paper 5: A Ray-Tracing Analysis of the Absorption of Light by Smooth and 143 Rough Metal Surfaces Paper 6: The Absorption of Light by Rough Metal Surfaces - A Three- 179 Dimensional Ray-Tracing Analysis iv Introduction Introduction 1. Motivation of the thesis Metal processing with lasers has reached a high level of maturity and acceptance in industry. It is used for cutting, drilling, welding, forming, engraving, marking, hardening and various forms of surface treatment of metals in a broad spectrum of modern industries, including the automotive and aerospace industries, the shipbuilding industry, the microelectronics industry and the medical instrument industry to name a few. Common to all these applications, is that the laser light is transformed into heat. This is the fundamental process of light absorption and can often be a determining factor in whether a process will be successful for a particular material under certain circumstances or not. In the field of material optics the studies of light interaction with metals have usually been concentrated on pure metallic elements with surfaces as smooth and clean as possible. This is understandable from the point of view of finding correlation with existing theories from solid state and condensed matter physics. If any handbook of chemistry or physics is picked up from a library, this is usually the experimental data that will be found. However, the engineering grade metals and metallic alloys found in real life processing with lasers have various forms of texture and roughness on their surfaces and also have layers of oxides on top of them. The sparse amount of experimental data and mathematical models for these kinds of non-perfect but more realistic surfaces is a limitation to the modellers of laser metal processing who need accurate heat input data for their heat conduction problems. The main motivation for this research was to provide more realistic information about the absorption of laser light by engineering metal surfaces. 2. Methodological approach The methodological approach of this Doctoral thesis can be understood by reference to the structure and order of the papers included. The work began by making an overview of the existing mathematical models of laser absorption in 1 Introduction metals (see Paper 1 for details) and this lead to a realisation of the lack of theory and experimental data for the engineering grade metals and metallic alloys found in real life processing applications. A study and review of the available experimental methods for measuring laser absorption in metals was then initiated and a potential candidate was found in the method of measuring reflectance using an integrating sphere.
Load more

Recommended publications
  • Platinum Sponsor
    We like to thank the Department of Biotechnology (Government of India) for financial support. We like to thank our sponsors for financial support: Platinum Sponsor: Gold Sponsor: Silver Sponsors: And Program Date Venue Timings Title OF MUSIC, MATH AND MEASUREMENT LH1 6pm M.W. Linscheid, Humbold Universitaet Berlin, Germany Dining Mixer 23/08 7pm Complex Concert by Ananth Menon Quartet Dining 8pm Dinner Complex LH1 9:00am Tutorial I MASS SPECTROMETRIC ESSENTIALS IN OMICS RESEARCH D.Schwudke LH1 9:30am Session I / Proteomics (Chair D. Schwud ke) MASS SPECTROMETRIC IDENTIFICATION OF A NOVEL TRANS- SPLICING EVENT IN GIARDIA LAMBLIA HEAT SHOCK PROTEIN 90 U.S. Tatu, IISC Bangalore, India REVISITING PROTEOMICS OF GLIOMAS: DIFFERENTIAL MEMBRANE PROTEINS AND MOLECULAR INSIGHTS R. Sirdeshmukh, IOB Bangalore, India NEW HIGH SELECTIVITY WORKFLOWS FOR TARGETED QUANTITATIVE PROTEOMICS 24/08 M. Cafazzo, AB Sciex, US Break ABSOLUTE QUANTIFICATION OF PROTEINS AND PEPTIDES - USE OF METAL CODING AND LC/MS WITH ICP AND ELECTROSPRAY M.W. Linscheid, Humbold Universitaet Berlin, Germany MATERNAL VITAMIN B12 DEFICIENCY INDUCED ALTERATION IN PROTEIN EXPRESSION IN RAT OFFSPRING S. Sengupta, IGIB New Dehli, India CLINICAL PROTEOMICS OF EYE DISEASES K. Dharmalingam, Madurai Kamaraj University, India Dining 1pm Lunch Complex Ope n 2pm Poster Session I Deck Date Venue Timings Title LH1 4pm Session II / Lipidomics (Chair S. Hebbar ) TOWARDS THE COMPLETE STRUCTURE ELUCIDATION OF COMPLEX LIPIDS BY MASS SPECTROMETRY: NOVEL APPROACHES TO ION ACTIVATION S. Blanksby et al., University of Wollongong, Australia LIPIDOMICS AT THE HIGH MASS RESOLUTION A. Shevchenko, MPI-CBG Dresden, Germany STRATEGIES FOR IMAGING BIOMOLECULES BY TOF-SIMS AND MALDI-TOF/TOF MASS SPECTROMETRY O.
    [Show full text]
  • Unraveling Resistive Versus Collisional Contributions to Relativistic Electron Beam Stopping Power in Cold-Solid and in Warm-Dense Plasmas B
    Unraveling resistive versus collisional contributions to relativistic electron beam stopping power in cold-solid and in warm-dense plasmas B. Vauzour,1, 2 A. Debayle,3, 4 X. Vaisseau,1 S. Hulin,1 H.-P. Schlenvoigt,5 D. Batani,1, 6 S.D. Baton,5 J.J. Honrubia,3 Ph. Nicola¨ı,1 F.N. Beg,7 R. Benocci,6 S. Chawla,7 M. Coury,8 F. Dorchies,1 C. Fourment,1 E. d'Humi`eres,1 L.C. Jarrot,7 P. McKenna,8 Y.J. Rhee,9 V.T. Tikhonchuk,1 L. Volpe,6 V. Yahia,5 and J.J. Santos1, a) 1)Univ. Bordeaux, CNRS, CEA, CELIA (Centre Lasers Intenses et Applications), UMR 5107, F-33405 Talence, France 2)Laboratoire d'Optique Appliqu´ee,ENSTA-CNRS-Ecole Polytechnique, UMR 7639, 91761 Palaiseau, France 3)ETSI Aeron´auticos, Universidad Polit´ecnica de Madrid, Madrid, Spain 4)CEA, DAM, DIF, F-91297 Arpajon, France 5)LULI, Ecole Polytechnique CNRS/CEA/UPMC, 91128 Palaiseau Cedex, France 6)Dipartimento di Fisica, Universit`adi Milano-Bicocca, Milano 20126, Italy 7)University of California, San Diego, La Jolla, California 92093, USA 8)SUPA, Department of Physics, University of Strathclyde, Glasgow G4 0NG, United Kingdom 9)Korea Atomic Energy Research Institute (KAERI), Daejon 305-600, Korea (Dated: 18 February 2014) We present results on laser-driven relativistic electron beam propagation through aluminum samples, which are either solid and cold, or compressed and heated by laser-induced shock. A full numerical description of fast electron generation and transport is found to reproduce the experimental absolute Kα yield and spot size measurements for varying target thickness, and to sequentially quantify the collisional and resistive electron stopping powers.
    [Show full text]
  • Influence of the Conditions of Selective Laser Melting on Evaporation
    MATEC Web of Conferences 224, 01060 (2018) https://doi.org/10.1051/matecconf/201822401060 ICMTMTE 2018 Influence of the conditions of selective laser melting on evaporation Roman S. Khmyrov1,*, Сyrill E. Protasov1, and Andrey V. Gusarov1 1Moscow State University of Technology “STANKIN”, 127055, Vadkovskii per. 1, Moscow, Russia Abstract. The paper presents the results of optical diagnostics of evaporation and displacement of powder fractions during the formation of a single track in the process of selective laser melting. The velocity of the powder fractions is estimated. It was defined, that an increase in the scanning speed leads to an decrease in the particle coming out rate from the molten pool and the rate at which they are attracted. The results allow evaluating the kinetics of the mass-transfer process during selective laser melting. It was clearly shown the material quality properties after the selective laser melting are strongly influenced by the formed thermal field in the laser-irradiated zone. 1 Introduction Laser material processing becomes already quite common in the modern industry, for example such processes as laser cutting, welding, drilling, marking. Technologies of additive manufacturing (growing) of parts from metal powders are also becoming more popular and characterizing by fundamentally different manufacturing strategy: layer by layer. It should be mentioned, that the lack of theoretical apparatus describing the process technology is the fundamental problem in the field of laser treatment. Such fundamental problems which are necessary to solve are: powder consolidation kinetics and its dependence of process parameters, intensive powder release (slopping) from powder consolidation zone: its causes, methods of influence on it; physical mechanisms leading to geometry instability of fused bead, instability at overcharged and undercharged scanning speeds of the laser beam relative to the optimal values, mechanisms of integration of individual track in a single one.
    [Show full text]
  • Chapter 2 HISTORY and DEVELOPMENT of MILITARY LASERS
    History and Development of Military Lasers Chapter 2 HISTORY AND DEVELOPMENT OF MILITARY LASERS JACK B. KELLER, JR* INTRODUCTION INVENTING THE LASER MILITARIZING THE LASER SEARCHING FOR HIGH-ENERGY LASER WEAPONS SEARCHING FOR LOW-ENERGY LASER WEAPONS RETURNING TO HIGHER ENERGIES SUMMARY *Lieutenant Colonel, US Army (Retired); formerly, Foreign Science Information Officer, US Army Medical Research Detachment-Walter Reed Army Institute of Research, 7965 Dave Erwin Drive, Brooks City-Base, Texas 78235 25 Biomedical Implications of Military Laser Exposure INTRODUCTION This chapter will examine the history of the laser, Military advantage is greatest when details are con- from theory to demonstration, for its impact upon the US cealed from real or potential adversaries (eg, through military. In the field of military science, there was early classification). Classification can remain in place long recognition that lasers can be visually and cutaneously after a program is aborted, if warranted to conceal hazardous to military personnel—hazards documented technological details or pathways not obvious or easily in detail elsewhere in this volume—and that such hazards deduced but that may be relevant to future develop- must be mitigated to ensure military personnel safety ments. Thus, many details regarding developmental and mission success. At odds with this recognition was military laser systems cannot be made public; their the desire to harness the laser’s potential application to a descriptions here are necessarily vague. wide spectrum of military tasks. This chapter focuses on Once fielded, system details usually, but not always, the history and development of laser systems that, when become public. Laser systems identified here represent used, necessitate highly specialized biomedical research various evolutionary states of the art in laser technol- as described throughout this volume.
    [Show full text]
  • A Light Over All Processes Cnc-Powered Laser Innovation Laser Use in Manufacturing Grows Welding Applications Expand
    LASER FOCUS — A SPECIAL SECTION I R O M G M D of esy urt Co LASERS TODAY: A LIGHT OVER ALL PROCESSES CNC-POWERED LASER INNOVATION LASER USE IN MANUFACTURING GROWS WELDING APPLICATIONS EXPAND A laser cutting head, mounted to the end effector of a robot, is robust and compact to withstand the challenging environment while having internal sensors and mechanisms that provide accuracy and feature capabilities that are beyond the normal capacity of the robot. Courtesy of Laser Mechanisms Inc. LASERS: A LIGHT OVER ALL PROCESSES AND MARKETS SME’s Industrial Laser Community Geoff Shannon, PhD, Laser Technology Manager—Miyachi America, and Mark Taggart, President—Laser Mechanisms Inc. s we approach the 50-year anniversary of laser use in manu- facturing, the use of lasers to make things is accelerating and expanding. Laser applications that just a few years ago were thought to be impossible or too expensive are Abecoming feasible and cost effective. Lasers, in fact, touch all of our lives on a daily basis. With great preci- sion and efficiency, lasers: • cut the glass for our smartphone and tablet screens; • weld the hard disk drives in our PCs and laptops; • cut airbag material and weld airbag detonators in our cars; • drill the fuel injectors in our engines to increase fuel economy; and • cut medical stents that enhance our lives. MfgEngMedia.com LF3 What’s more, remarkable, fast-paced advances in specialized optics and high-speed beam delivery computers, sensor technologies, and wireless com- systems, and non-metals welding and processing. munications are creating increasingly sophisticated Advancements in the field of laser additive manufac- tools such as process monitors and system diagnostics turing have also caught the attention of the public that are enhancing the performance, reliability and and the media.
    [Show full text]
  • Flow Diagnostics Produced by Selective Laser Melting of Cutting Nozzles
    Lasers in Manufacturing Conference 2015 Flow diagnostics produced by selective laser melting of cutting nozzles S.Ulricha, S.Lorenza S. Jahna, S.Sändiga, B.Fleckb aGünter-Köhler-Institut für Fügetechnik und Werkstoffprüfung GmbH bErnst-Abbe-Hochschule Jena Abstract The increasing spread of laser technology in materials processing leads inter alia increasingly individual solution strategies in order to cope with the growing demands on the process control. The focus of this work is the fluidic analysis of the cutting nozzles, which were usually produced either by selective laser melting or conventional methods. The Schlieren measurement was utilized in order to visualize flows. Through the adjustment of optical components, the Schlieren-Aufnahmegerät 80 was coupled with a high speed camera. Based on these measurement results, the influence of manufacturing technology has been evaluated on the flow behaviour. With the help of cutting tests a direct proof of the achievable quality of the cutting edge has been evaluated. The results from both research methods provide a statement on the quality of the gas stream and the achievable cutting quality of manufacturing technology. Keywords: laser cutting, selektiv laser melting, nozzle, flow visualization 1. Introduction Nowadays, the decisive factors for financial success are on the one hand innovative products, and on the other hand the acquisition of knowledge through research and development. In materials processing, the application of lasers in technological fields like cutting and welding, enables shorter lead times. The understanding of the process plays a crucial role for the quality of the component. Regarding cutting, the quality of the cut edge and the dimensional accuracy is affected by many parameters.
    [Show full text]
  • A Laser (From the Acronym Light Amplification by Stimulated Emission of Radiation) Is an Optical Source That Emits Photons in a Coherent Beam
    LASER A laser (from the acronym Light Amplification by Stimulated Emission of Radiation) is an optical source that emits photons in a coherent beam. The verb to lase means "to produce coherent light" or possibly "to cut or otherwise treat with coherent light", and is a back- formation of the term laser. Laser light is typically near-monochromatic, i.e. consisting of a single wavelength or color, and emitted in a narrow beam. This is in contrast to common light sources, such as the incandescent light bulb, which emit incoherent photons in almost all directions, usually over a wide spectrum of wavelengths. Laser action is explained by the theories of quantum mechanics and thermodynamics. Many materials have been found to have the required characteristics to form the laser gain medium needed to power a laser, and these have led to the invention of many types of lasers with different characteristics suitable for different applications. The laser was proposed as a variation of the maser principle in the late 1950's, and the first laser was demonstrated in 1960. Since that time, laser manufacturing has become a multi- billion dollar industry, and the laser has found applications in fields including science, industry, medicine, and consumer electronics. Contents [hide] 1 Physics 2 History 2.1 Recent innovations 3 Uses 3.1 Popular misconceptions 3.2 "LASER" 3.3 Scientific misconceptions 4 Laser safety 5 Categories 5.1 By type 5.2 By output power 6 See also 7 Further reading 7.1 Books 7.2 Periodicals 8 References 9 External links [edit] Physics See also: Laser science Principal components: 1.
    [Show full text]
  • Acrylic-Processing-Guide.Pdf
    Laser Processing Guide working with acrylic www.troteclaser.com www.trotec-materials.com Acrylic is becoming an increasingly popular manufacturing material used across many industries for a wide range of products such as signs, displays and trophies, to name a few. It is highly versatile, durable, aesthetically pleasing, and processes well with a laser. For many, acrylic is a convenient and affordable alternative to glass because it’s largely impact-resistant and weighs about half as much, but still offers a high level of clarity. A laser is a highly effective and efficient way to cut, mark or engrave acrylic. Including general processing instructions and pointers, time-saving tricks and troubleshooting advice, the following guide was designed to help new laser users as well as intermediate users improve their acrylic processing technique and results. With a little practice and a few pointers, you will be able to use your laser to create perfectly polished acrylic edges, engrave intricate details, and produce precise cuts and contours. Getting 01 Started Engraving Processing Techniques and 02 Recommended Settings Cutting Processing Techniques and 03 Recommended Settings Common 05 Mistakes Trouble 06 Shooting Getting Started Acrylic materials come in a wide range of color, texture, and finish combinations. There are three main types of acrylic: Cell Cast Acrylic that is cast into shapes • Laser engraving appears frosted • Laser cutting easy Continuous Cast Acrylic that is continuously casted into sheets using a sheet shape molded on an assembly line • Laser engraving appears frosted • Laser cutting easy Extruded • Laser engraving is translucent, making it difficult to see • Can be easily cut with a laser using lower power settings.
    [Show full text]
  • Annual Report of Kansai Research Establishment 1999 October 1,1995-March 31,2000
    JP0150335 ANNUAL REPORT OF KANSAI RESEARCH ESTABLISHMENT 1999 OCTOBER 1,1995-MARCH 31,2000 i h Kansai Research Establishment Japan Atomic Energy Research Institute Mi, m&mntimm (T319-1195 4 is, ^ - (T319-1195 This report is issued irregularly. Inquiries about availability of the reports should be addressed to Research Information Division, Department of Intellectual Resources, Japan Atomic Energy Research Institute, Tokai-mura, Naka-gun, Ibaraki-ken T 319-1195, Japan. © Japan Atomic Energy Research Institute, 2001 JAERI-Review 2001-003 Annual Report of Kansai Research Establishment 1999 October 1,1995~March 31,2000 Kansai Research Establishment Japan Atomic Energy Research Institute Kizu-cho, Souraku-gun, Kyoto-fu (Received January 15,2001) This report is the first issue of the annual report of Kansai Research Establishment, Japan Atomic Energy Research Institute. It covers status reports of R&D and results of experiments conducted at the Advanced Photon Research Center and the Synchrotron Radiation Research Center during the period from October 1,1995 to March 31, 2000. Keywords: Annual Report, Kansai Research Establishment, JAERI, R&D, Advanced Photon Research Center, Synchrotron Radiation Research Center Board of Editors for Annual Report Editors: Takashi ARISAWA (Chief editor), Osamu SfflMOMURA, AMra NAGASfflMA, Norio OGIWARA, Mitsuru YAMAGIWA, Masato KOIKE, Kazuhisa NAKAJIMA, Eisuke MINEHARA, TeiMchi SASAKI, Jun-ichiro MZUKI, Yuji BABA, Atsushi FUJIMORI Editorial assistants: Noboru TSUCHIDA, Sayaka HARAYAMA, Shuichi FUJITA, Tsutomu WATANABE, Hironobu OGAWA JAERI-Review 2001-003 1999 1995 ¥ 10 J! 1 H-2000¥3^ 31 0 (2001 ¥U! 15 V s 1995 ¥ 10 M frh 2000 ¥ 3 31 : T 619-0215 •8-1 JAERI-Review 2001-003 Contents * OUXXXULXdl V —————————————————————————————--—————"-•-————•-•-——--——•-•-•---—--————————————————————•-———————————————————— a 2.
    [Show full text]
  • Laser Study on Q-Switch of Cr4 +: YAG Self-Saturated Crystals
    Insight - Physics(2018.1) Original Research Article Laser Study on Q-switch of Cr4 +: YAG Self-saturated Crystals Yonghui Lin,Xiao Wang,Xiaodong Zhao Department of Physics, Langfang Jiaotong University, Hebei, China ABSTRACT In recent years, with the rapid development of computer technology applications, computer simulation experiments have been widely used in various fields of science and application, plays an important and indispensable role. Similarly, computer simulation experiments in laser research are also important; it can be a limited amount of time in a large number of repeated experiments, resulting in the characteristics of the laser curve to study. If the same actual experiment, the time required is very long, the investment of funds is huge. So through the computer simulation experiment to guide the actual experiment, can study the smooth progress. It is the guarantee of actual experiment. KEYWORDS: - 1. Introduction Solid tunable laser has the advantages of compact structure, wide tuning range, convenient tuning, large output power and high repetition rate. It quickly replaced the dye tunable laser as the active fi eld of laser research. The tunable range of Cr4 + ions can cover the spectral region of 1.1μm-1.8μm, which includes many very important bands, such as the zero loss of the fi ber, the zero dispersion area and the safety band of the human eye. In the optoelectronic information technology, Spectroscopy, atmospheric measurement, environmental monitoring, life sciences and semiconductor materials research has important applications. In the Cr4 + ion as the activation of the central ion of the laser crystal, the transition metal ion solid tunable laser was successfully operated.
    [Show full text]
  • Techniques in Laser Cutting and Engraving Leather
    Where the Laser Meets the Leather: Techniques in Laser Cutting and Engraving Leather SARAH PIKE If you had ever told me that, as an artist trained in traditional figurative painting who works in stone lithography, I would end up running a laser cutting business, I wouldn't have believed you. But it was through my printmaking discipline and sensibilities that I came to work with laser cutting. And today I draw great satisfaction in helping artists—primarily bookbinders—bridge the gap between handcraft and new technologies. In this article I will share a variety of laser cutting and engraving techniques for working with leather and parchment. A Look at What's Possible Laser cutters, which vaporize material using a pulsating That said, the question I most often get is, “Can you cut beam of light, perform three main tasks: they cut, line metal?” The answer is no: a fiber laser is needed for engrave, and area engrave. When the laser cuts or line laser cutting metal. Due to their size and cost, fiber engraves, it follows the path of the line; when it area lasers are more often found at businesses that service engraves it moves back and forth like an ink-jet printer. industrial companies. Note that in this context, engraving refers to the partial removal of material that can be performed at multiple While I'll try to be as specific as possible, so many depths (fig. 1). variables come into play that it's difficult to give universal guidelines. Laser cutter settings can vary greatly depending on how the leather was processed, the dye used, what part of the skin is being used, and the life of the animal.
    [Show full text]
  • The Effect of the Laser Incidence Angle in the Surface of L-PBF
    coatings Article The Effect of the Laser Incidence Angle in the Surface of L-PBF Processed Parts Sara Sendino 1,* , Marc Gardon 2, Fernando Lartategui 3 , Silvia Martinez 1 and Aitzol Lamikiz 1 1 Aerospace Advance Manufacturing Research Center-CFAA, P. Tecnológico de Bizkaia 202, 48170 Zamudio, Spain; [email protected] (S.M.); [email protected] (A.L.) 2 EMEA AM Applications Manager, Renishaw Ibérica, Carrer de la Recerca 7, 08850 Barcelona, Spain; [email protected] 3 UO Structures & Statics, ITP Aero, P. Tecnológico de Bizkaia 300, 48170 Zamudio, Spain; [email protected] * Correspondence: [email protected] Received: 29 September 2020; Accepted: 22 October 2020; Published: 24 October 2020 Abstract: The manufacture of multiple parts on the same platform is a common procedure in the Laser Powder Bed Fusion (L-PBF) process. The main advantage is that the entire working volume of the machine is used and a greater number of parts are obtained, thus reducing inert gas volume, raw powder consumption, and manufacturing time. However, one of the main disadvantages of this method is the possible differences in quality and surface finish of the different parts manufactured on the same platform depending on their orientation and location, even if they are manufactured with the same process parameters and raw powder material. Throughout this study, these surface quality differences were studied, focusing on the variation of the surface roughness with the angle of incidence of the laser with respect to the platform. First, a characterization test was carried out to understand the behavior of the laser in the different areas of the platform.
    [Show full text]