DOCSLIB.ORG

Investigation of Surface Finish and Mrr During Abrasive Assisted Drilling on Polymer Matrix Composite Material

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Investigation of Surface Finish and Mrr During Abrasive Assisted Drilling on Polymer Matrix Composite Material International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395 -0056 Volume: 02 Issue: 04 | July-2015 www.irjet.net p-ISSN: 2395-0072 INVESTIGATION OF SURFACE FINISH AND MRR DURING ABRASIVE ASSISTED DRILLING ON POLYMER MATRIX COMPOSITE MATERIAL. Dilpreet Singh1, Gurmeet Singh Chhatwal2, Mandeep Kumar3 1 Dept. of Mechanical Engineering, Punjab College of Engineering & Technology, Lalru Mandi, Punjab, India 2 Assistant Professor, Dept. of Mechanical Engineering, Punjab College of Engineering & Technology, Lalru Mandi, Punjab, India 3 Assistant Professor, Dept. of Mechanical Engineering, Chandigarh University, Gharuan, Punjab, India ---------------------------------------------------------------------***--------------------------------------------------------------------- Abstract - This report is concerned with investigating and tool life. Drilling is an essential operation in the the Surface finish when drilling POLYMER MATRIX assembly of the structural frames of automobiles and aircrafts. The life of a joint can be critically affected by the COMPOSITE (E-Glass) with HSS drill. This study included quality of the drilled holes. The growing demand for drilling of PMC with supply of Sic abrasive, Alumina higher productivity, product quality and overall economy Oxide Abrasive having grain size 800, 1000, 1200 mesh in manufacturing by machining, grinding and drilling, size through abrasive slurry system & with Coolant. particularly to meet the challenges thrown by Abrasives not only used for cooling purpose but also liberalization and global cost competitiveness, insists high increases the surface finish, MRR and reduce tool wear. material removal rate and high stability and long life of the cutting tools. However, high production machining and Experiments were conducted on a CNC Drilling machine. grinding with high cutting velocity, feed and depth of cut is Taguchi is applied for executing the planning of inherently associated with generation of large amount of experiments. The drilling parameters namely Feed rate heat and high cutting temperature. Such high cutting (mm/min) ,Spindle speed (rpm) ,Type of abrasive grain temperature not only reduces dimensional accuracy and size ,Slurry Concentration ,Type of Abrasive (Silicon tool life but also impairs the surface finish of the product. Carbide, Alumina oxide), were optimized using multiple One estimate is that 75% of all metal-cutting material performance characteristics for Surface Finish. The removed comes from drilling operations. Drilled holes are characterized by their sharp edge on the entrance side and result shows that the feed rate, Type of Abrasive & the presence of burrs on the exit side (unless they have slurry concentration are the most significant factors been removed). which affect the Surface finish in the drilling can be We all know that the 20th century has witnessed effectively improved by using this approach revolutions in a number of fields like computer, Radar, space, missiles, etc. but the most interesting Key Words: Abrasives, ANOVA, Drilling, Taguchi changes have taken place in the area of polymer matrix composites. In the literature review we will review the Technique, Polymer Matrix Composite material E- surface roughness and material removal rate, Taguchi Glass , Surface roughness, MRR. technique. 2. LITERATURE REVIEW 1. INTRODUCTION J.Pradeep Kumar analyzed that to utilize Taguchi method Drilling is one of the most fundamental machining to investigate the effects of drilling parameters on surface processes. It is most frequently performed in material roughness, tool wear by weight, material removal rate and removal and is used as a preliminary step for many hole diameter error in drilling of OHNS material using HSS operations such as reaming, tapping and boring. It is spiral drill. Orthogonal arrays of Taguchi, the Signal–to- moving toward high speed applications for productivity Noise (S/N) ratio, the analysis of variance (ANOVA), and enhancement. Drilling is a process of producing round regression analysis are employed to analyze the effect of hole in solid material or enlarging existing hole with the drilling parameters on the quality of drilled holes. A series use of multi-point cutting tools called drill or drill bits. of experiments based on L18 orthogonal array are Various cutting tools are 297blind hole in a solid material. conducted. The experimental results are collected and It has found that high production machining and drilling analyzed using commercial software package MINITAB 13. with high cutting velocity, feed and depth of cut is Linear regression equations are developed with an inherently associated with generation of large amount of objective to establish a correlation between the selected heat and high cutting temperature which reduces accuracy drilling parameters with the quality characteristics of the © 2015, IRJET.NET- All Rights Reserved Page 297 International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395 -0056 Volume: 02 Issue: 04 | July-2015 www.irjet.net p-ISSN: 2395-0072 drilled holes. The predicted values are compared with assisted drilling have lesser thrust and hence lesser de- experimental data and are found to be in good agreement lamination compared to conventional drilling, which [1]. indicates that both vibration assisted drilling and Ultrasonic assisted drilling are more appropriate for Yogendra Tyagi investigated that the drilling of mild drilling of GFRP [4]. steel with the help of CNC drilling machine operation with high speed steel by applying Taguchi methodology has B. Ramesh investigated that a non laminated Glass Fiber been reported. The Taguchi method is applied to Reinforced Plastic (GFRP) composite manufactured by formulate the experimental layout to ascertain the pultrusion process was drilled with a coated cemented element of impact each optimum process parameters for carbide drill. The thrust force and torque during drilling CNC drilling machining with drilling operation of mild were acquired through piezoelectric dynamometer and steel. A L9 array, Taguchi method and analysis of variance damage factor was measured using metallurgical (ANOVA) are used to formulate the procedure tried on the microscope. Taguchi’s orthogonal array and analysis of change of parameter layout. The available material study variance (ANOVA) were employed to study the influence in focuses optimization of CNC Drilling machine process of process parameters such as feed and spindle speed on parameters to provide good surface finish as well as high thrust force, torque and damage factor. The optimum level material removal rate (MRR).The surface finishing and of process parameters towards minimum thrust force, material removal rate have been identified us quality minimum torque and lower damage factor were obtained attribute and are assumed to be directly related to to achieve defect controlled drilling of GFRP composites. productivity. The selection of optimal machining Correlations for thrust force, torque and damage factor parameters i.e., spindle speed, depth of cut and feed rate) with process parameters were established using statistical for drilling machine operations was investigated in order software MINITAB 15. Among the process parameters to minimize the surface roughness and to maximize the examined, feed significantly influences both the thrust material removal rate [2]. force and torque with 88.52% and 92.83% respectively whereas the influence of spindle speed on the above was Arshad Noor Siddiquee had focused on optimizing deep relatively insignificant. The influence of feed and spindle drilling parameters based on Taguchi method for speed on damage factor at both entrance and exit of the minimizing surface roughness. The experiments were work piece was insignificant [5]. conducted on CNC lathe machine using solid carbide cutting tool on material AISI 321 austenitic stainless steel. 3. MACHINING SETUP Four cutting parameters such as cutting fluid, speed, feed For the entire experiment Computer Numerical Machine and hole-depth, each at three levels except the cutting (FAMUP Machining Centre) was used shown in fig 1. The fluid at two levels were considered. Taguchi L18 abrasive slurry of Silicon Carbide and Alumina Oxide of orthogonal array was used as design of experiment. The grit size 800, 1000, 1200 was cutting fluid for signal-to-noise (S/N) ratio and the analysis of variance experimentation. The slurry was used with varying (ANOVA) was carried out to determine which machining concentration of 20%, 25%, and 30%. The work material parameter significantly affects the surface roughness and used for the experimentation is Polymer matrix composite also the percentage contribution of individual parameters. (E-Glass). Then surface roughness of machined surface Confirmation test was conducted to ensure validity of the was measured with the help of Mtiutoyo SJ-201P for all the test result. It is observed that the surface finish for deep machined samples. Average surface roughness "Ra" was drilling process can be improved effectively through this measured. approach [3]. B.V.Kavad had studied that drilling is an important process for making and assembling components made from Glass Fiber Reinforced Plastic (GFRP). Various processes like conventional drilling, vibration assisted drilling and ultrasonic assisted drilling have been attempted in order to maintain the integrity of the material and obtain the necessary accuracy in drilling of GFRP. This paper attempts to review the influence
Load more

Recommended publications
  • Guide to Stainless Steel Finishes
    Guide to Stainless Steel Finishes Building Series, Volume 1 GUIDE TO STAINLESS STEEL FINISHES Euro Inox Euro Inox is the European market development associa- Full Members tion for stainless steel. The members of Euro Inox include: Acerinox, •European stainless steel producers www.acerinox.es • National stainless steel development associations Outokumpu, •Development associations of the alloying element www.outokumpu.com industries. ThyssenKrupp Acciai Speciali Terni, A prime objective of Euro Inox is to create awareness of www.acciaiterni.com the unique properties of stainless steels and to further their use in existing applications and in new markets. ThyssenKrupp Nirosta, To assist this purpose, Euro Inox organises conferences www.nirosta.de and seminars, and issues guidance in printed form Ugine & ALZ Belgium and electronic format, to enable architects, designers, Ugine & ALZ France specifiers, fabricators, and end users, to become more Groupe Arcelor, www.ugine-alz.com familiar with the material. Euro Inox also supports technical and market research. Associate Members British Stainless Steel Association (BSSA), www.bssa.org.uk Cedinox, www.cedinox.es Centro Inox, www.centroinox.it Informationsstelle Edelstahl Rostfrei, www.edelstahl-rostfrei.de Informationsstelle für nichtrostende Stähle SWISS INOX, www.swissinox.ch Institut de Développement de l’Inox (I.D.-Inox), www.idinox.com International Chromium Development Association (ICDA), www.chromium-asoc.com International Molybdenum Association (IMOA), www.imoa.info Nickel Institute, www.nickelinstitute.org
    [Show full text]
  • 5.1 GRINDING Definitions
    UNIT-V GRINDING AND BROACHING 5.1 Grinding Definitions Cutting conditions in grinding Wheel wear Surface finish and effects of cutting temperature Grinding wheel Grinding operations Finishing Processes Introduction Finishing processes 5.1 GRINDING Definitions Abrasive machining is a material removal process that involves the use of abrasive cutting tools. There are three principle types of abrasive cutting tools according to the degree to which abrasive grains are constrained, bonded abrasive tools: abrasive grains are closely packed into different shapes, the most common is the abrasive wheel. Grains are held together by bonding material. Abrasive machining process that use bonded abrasives include grinding, honing, superfinishing; coated abrasive tools: abrasive grains are glued onto a flexible cloth, paper or resin backing. Coated abrasives are available in sheets, rolls, endless belts. Processes include abrasive belt grinding, abrasive wire cutting; free abrasives: abrasive grains are not bonded or glued. Instead, they are introduced either in oil-based fluids (lapping, ultrasonic machining), or in water (abrasive water jet cutting) or air (abrasive jet machining), or contained in a semisoft binder (buffing). Regardless the form of the abrasive tool and machining operation considered, all abrasive operations can be considered as material removal processes with geometrically undefined cutting edges, a concept illustrated in the figure: The concept of undefined cutting edge in abrasive machining. Grinding Abrasive machining can be likened to the other machining operations with multipoint cutting tools. Each abrasive grain acts like a small single cutting tool with undefined geometry but usually with high negative rake angle. Abrasive machining involves a number of operations, used to achieve ultimate dimensional precision and surface finish.
    [Show full text]
  • TUFFAK® Polycarbonate Sheet Fabrication Guide (At Curbell Plastics)
    TUFFAK® polycarbonate sheet Fabrication guide / Technical manual Table of Contents Page Introduction ..................................... 3 Typical Properties ................................ 4 TUFFAK Product Selection Guide................ 5-6 Chemical / Environmental Resistance ............7-13 Cleaning Recommendations ...................14-15 Fabrication / Machining........................16-21 Fabrication / Laminate & Heavy Gauge Sheet .. 22-25 Thermoforming ...............................26-31 Troubleshooting Guide .......................32-40 Brake Bending, Cold Forming, Annealing .......41-42 Bonding Applications.........................43-45 Mechanical Fastening.........................46-49 Finishing.....................................50-52 Glazing Guidelines ...........................53-58 2 Contact Technical Service Group with additional questions: 800.628.5084 [email protected] 3 TUFFAK Sheet Typical Properties* Property Test Method Units Values PHYSICAL Specific Gravity ASTM D 792 – 1.2 Refractive Index ASTM D 542 – 1.586 Light Transmission, Clear @ 0.118˝ ASTM D 1003 % 86 Light Transmission, I30 Gray @ 0.118˝ ASTM D 1003 % 50 Light Transmission, K09 Bronze @ 0.118˝ ASTM D 1003 % 50 Light Transmission, I35 Dark Gray @ 0.118˝ ASTM D 1003 % 18 Water Absorption, 24 hours ASTM D 570 % 0.15 Poisson’s Ratio ASTM E 132 – 0.38 MECHANICAL Tensile Strength, Ultimate ASTM D 638 psi 9,500 Tensile Strength, Yield ASTM D 638 psi 9,000 Tensile Modulus ASTM D 638 psi 340,000 Elongation ASTM D 638 % 110 Flexural Strength ASTM D
    [Show full text]
  • Understanding Surface Quality: Beyond Average Roughness (Ra)
    Paper ID #23551 Understanding Surface Quality: Beyond Average Roughness (Ra) Dr. Chittaranjan Sahay P.E., University of Hartford Dr. Sahay has been an active researcher and educator in Mechanical and Manufacturing Engineering for the past four decades in the areas of Design, Solid Mechanics, Manufacturing Processes, and Metrology. He is a member of ASME, SME,and CASE. Dr. Suhash Ghosh, University of Hartford Dr. Ghosh has been actively working in the areas of advanced laser manufacturing processes modeling and simulations for the past 12 years. His particular areas of interests are thermal, structural and materials modeling/simulation using Finite Element Analysis tools. His areas of interests also include Mechanical Design and Metrology. c American Society for Engineering Education, 2018 Understanding Surface Quality: Beyond Average Roughness (Ra) Abstract Design of machine parts routinely focus on the dimensional and form tolerances. In applications where surface quality is critical and requires a characterizing indicator, surface roughness parameters, Ra (roughness average) is predominantly used. Traditionally, surface texture has been used more as an index of the variation in the process due to tool wear, machine tool vibration, damaged machine elements, etc., than as a measure of the performance of the component. There are many reasons that contribute to this tendency: average roughness remains so easy to calculate, it is well understood, and vast amount of published literature explains it, and historical part data is based upon it. It has been seen that Ra, typically, proves too general to describe surface’s true functional nature. Additionally, the push for complex geometry, coupled with the emerging technological advances in establishing new limits in manufacturing tolerances and better understanding of the tribological phenomena, implies the need for surface characterization to correlate surface quality with desirable function of the surface.
    [Show full text]
  • Surface Finish Measurement Objectives
    Surface Finish Measurement Objectives • Interpret the surface finish symbols that appear on a drawing • Use a surface finish indicator to measure the surface finish of a part Surface Finish Measurement • Modern technology demanding improved surface finishes • Often require additional operations: lapping or honing • System of symbols devised by ASA • Provide standard system of determining and indicating surface finish • Inch unit is microinch (µin) • Metric unit is micrometer (µm) Surface Indicator • Tracer head and amplifier • Tracer head has diamond stylus, point radius .0005 µin that bears against work surface • Movement caused by surface irregularities converted into electrical fluctuations • Signals magnified by amplifier and registered on meter • Reading indicates average height of surface Readings Either arithmetic average roughness height (Ra) or root mean square (Rq) Symbols Used to Identify Surface Finishes and Characteristics 18-6 Surface Finish Definitions • Surface deviations: departures from nominal surface in form of waviness, roughness, flaws, lay, and profile • Waviness: surface irregularities that deviate from mean surface in form of waves • Waviness height: peak-to-valley distance in inches or millimeters • Waviness width: distance between successive waviness peaks or valleys in inches or millimeters Surface Finish Definitions • Roughness: relatively finely spaced irregularities superimposed on waviness pattern • Caused by cutting tool or abrasive grain action • Irregularities narrower than waviness pattern • Roughness
    [Show full text]
  • A Study of Micro- and Surface Structures of Additive Manufactured Selective Laser Melted Nickel Based Superalloys
    DEGREE PROJECT IN TECHNOLOGY, FIRST CYCLE, 15 CREDITS STOCKHOLM, SWEDEN 2016 A study of micro- and surface structures of additive manufactured selective laser melted nickel based superalloys EMIL STRAND, ALEXANDER WÄRNHEIM KTH ROYAL INSTITUTE OF TECHNOLOGY SCHOOL OF INDUSTRIAL ENGINEERING AND MANAGEMENT Abstract This study examined the micro- and surface structures of objects manufactured by selective laser melting (SLM). The results show that the surface roughness in additively manufactured objects is strongly dependent on the geometry of the built part whereas the microstructure is largely unaffected. As additive manufacturing techniques improve, the application range increases and new parameters become the limiting factor in high performance applications. Among the most demanding applications are turbine components in the aerospace and energy industries. These components are subjected to high mechanical, thermal and chemical stresses and alloys customized to endure these environments are required, these are often called superalloys. Even though the alloys themselves meet the requirements, imperfections can arise during manufacturing that weaken the component. Pores and rough surfaces serve as initiation points to cracks and other defects and are therefore important to consider. This study used scanning electron-, optical- and focus variation microscopes to evaluate the microstructures as well as parameters of surface roughness in SLM manufactured nickel based superalloys, Inconel 939 and Hastelloy X. How the orientation of the built part affected the surface and microstructure was also examined. The results show that pores, melt pools and grains where not dependent on build geometry whereas the surface roughness was greatly affected. Both the Rz and Ra values of individual measurements were almost doubled between different sides of the built samples.
    [Show full text]
  • Abrasive Cutting Abrasive Cutting
    ABRASIVEABRASIVE CUTTINGCUTTING I. INTRODUCTION II. ABRASIVE MATERIALS Abrasive have been used as cutting tools since In the early stages of abrasive cutting, the the dawn of civilisation. In the early stages of products were made with natural materials like industrialisation, there was a tendency to move sand, emery, corundum etc. A great impetus to development was the manufacture of synthetic towards other cutting materials, but this process abrasive aluminium oxide and silicon carbide. has recently stopped and, in fact, there is now These two abrasive materials were gradually a trend to replace many conventional cutting refined to achieve the optimum characteristics operations with abrasive methods. In advanced in terms of hardness, friability, sharpness, industrial countries, almost 25% of all machining thermal resistance etc. The increasing use of operations are done with abrasives and this high alloy steels, aero-space alloys, carbide percentage is expected to rise to 50% in the next tools and ceramics led to the development of decade. This fantastic growth is due to the on- new abrasives like synthetic diamond, boron going research in the abrasives industry which carbide and boron nitride. The growth of the has resulted in the development of sophisticated metallurgical industry and increasing popularity abrasive products and processes catering to of grinding for metal conditioning led to the enhanced requirements in terms of productivity, development of Zirconium Oxide as an abrasive accuracy and quality. The chart shown in table material suitable for extremely heavy duty below gives an idea of the vast scope of operations. abrasive grinding processes. These range from III. ABRASIVE PRODUCTS traditional precision finishing operations through The numerous abrasive cutting operations fettling and cutting off, to the latest primary stock require a wide variety of abrasive products removal processes used in steel plants.
    [Show full text]
  • Investigation of Selective Laser Melting Fabricated Internal Cooling Channels
    Grand Valley State University ScholarWorks@GVSU Masters Theses Graduate Research and Creative Practice 4-2020 Investigation of Selective Laser Melting Fabricated Internal Cooling Channels Colin Jack Grand Valley State University Follow this and additional works at: https://scholarworks.gvsu.edu/theses Part of the Materials Science and Engineering Commons ScholarWorks Citation Jack, Colin, "Investigation of Selective Laser Melting Fabricated Internal Cooling Channels" (2020). Masters Theses. 971. https://scholarworks.gvsu.edu/theses/971 This Thesis is brought to you for free and open access by the Graduate Research and Creative Practice at ScholarWorks@GVSU. It has been accepted for inclusion in Masters Theses by an authorized administrator of ScholarWorks@GVSU. For more information, please contact [email protected]. Investigation of Selective Laser Melting Fabricated Internal Cooling Channels Colin Jack A Master’s Thesis Submitted to the Graduate Faculty of GRAND VALLEY STATE UNIVERSITY In Partial Fulfillment of the Requirements For the Degree of Engineering, M.S.E./B.S.E. Articulated Padnos College of Engineering and Computing April 2020 Acknowledgements I would like to express my deep gratitude to Dr. Pung for his guidance and resourcefulness throughout the arduous process of this investigation. I would also like to thank Dr. Hugh Jack and the Western Carolina University College of Engineering and Technology for assisting in the complex fabrication of the additively manufactured experimental samples. Lastly, I would like to extend this gratitude to my friends and family who inspire me and drive me to pursue great challenges. 3 Abstract Channels where coolant is run to cool a system are common in injection mold tooling.
    [Show full text]
  • Machining of Polycarbonate for Optical Applications A
    MACHINING OF POLYCARBONATE FOR OPTICAL APPLICATIONS A THESIS SUBMITTED TO THE GRADUATE SCHOOL OF NATURAL AND APPLIED SCIENCES OF MIDDLE EAST TECHNICAL UNIVERSITY BY MÜSLÜM BOLAT IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE IN MECHANICAL ENGINEERING SEPTEMBER 2013 Approval of the thesis: MACHINING OF POLYCARBONATE FOR OPTICAL APPLICATIONS submitted by MÜSLÜM BOLAT in partial fulfillment of the requirements for the degree of Master of Science in Mechanical Engineering Department, Middle East Technical University by, Prof. Dr. Canan Özgen ____________________ Dean, Graduate School of Natural and Applied Sciences Prof. Dr. Suha Oral ____________________ Head of the Department, Mechanical Engineering Prof. Dr. M. A. Sahir Arıkan ____________________ Supervisor, Mechanical Engineering Dept., METU Examining Committee Members: Prof. Dr. Mustafa Ġlhan Gökler ____________________ Mechanical Engineering Dept., METU Prof. Dr. M. A. Sahir Arıkan ____________________ Mechanical Engineering Dept., METU Prof. Dr. Tuna Balkan ____________________ Mechanical Engineering Dept., METU Prof. Dr. Can Çoğun ____________________ Mechanical Engineering Dept., Çankaya University Onat Totuk, M.Sc. ____________________ Mechanical Engineering Dept., Çankaya University Date: 03.09.2013 I hereby declare that all information in this document has been obtained and presented in accordance with academic rules and ethical conduct. I also declare that, as required by these rules and conduct, I have fully cited and referenced all material and results that are not original to this work. Name, Last Name : Müslüm BOLAT Signature : iv ABSTRACT MACHINING OF POLYCARBONATE FOR OPTICAL APPLICATIONS Bolat, Müslüm M.Sc., Department of Mechanical Engineering Supervisor: Prof. Dr. M. A. Sahir Arıkan September 2013, 94 pages Polycarbonate is a very strong and durable material, highly transparent to visible light, with superior light transmission compared to many kinds of glass.
    [Show full text]
  • Surface Finish: a Machinist's Tool
    Surface Finish: A Machinist's Tool. A Design Necessity. Simple "roughness" measurements remain useful in the increasingly stringent world of surface finish specifications. Here's a look at why surface measurement is important and how to use sophisticated portable gages to perform inspections on the shop floor. By Alex Tabenkin Mahr Federal, Inc. Surface finish, or texture, can be viewed from two very different perspectives. From the machinist's point of view, texture is a result of the manufacturing process. By altering the process, the texture can be changed. From the part designer's point of view, surface finish is a condition that affects the functionality of the part to which it applies. By changing the surface finish specification, the part's functionality can be altered—and hopefully, improved. Bridging the gap between these two perspectives is the manufacturing engineer, who must determine how the machinist is to produce the surface finish specified by the design engineer. The methods one chooses to measure surface finish, therefore, depend upon perspective, and upon what one hopes to achieve. What Is Surface Texture? Turning, milling, grinding and all other machining processes impose characteristic irregularities on a part's surface. Additional factors such as cutting tool selection, machine tool condition, speeds, feeds, vibration and other environmental influences further influence these irregularities. Texture consists of the peaks and valleys that make up a surface and their direction on the surface. On analysis, texture can be broken down into three components: roughness, waviness, and form. Roughness is essentially synonymous with tool marks. Every pass of a cutting tool leaves a groove of some width and depth.
    [Show full text]
  • 5. Dimensions, Tolerances and Surface
    5. DIMENSIONS, TOLERANCES AND SURFACE 5.1 Dimension, Tolerances and Related Attributes 5.2 Surfaces 5.3 Effect of Manufacturing Processes Introduction Dimensions – the sizes and geometric features of a component specified on the part drawing. How well the parts of a product fits together. Tolerance – Allowable variation in dimension. Surface – affects product performance, esthetic and ‘wear’ 5.1 Dimensions, Tolerance and Related Attributes Dimension – ‘a numerical value expressed in appropriate units of measure and indicated on a drawing along with lines, symbols and notes to define the size/geometric characteristics of a part’ Variations in the part size comes from manufacturing processes Tolerance – the limit of the allowed variation Tolerance Bilateral Tolerance Unilateral Tolerance Limit dimension Other Geometric Attributes Angularity Circularity Concentricity Cylindricity Flatness Parallelism Perpendicularity Roundness Squareness Straightness 5.2 Surface Nominal Surface - intended surface contour of part Actual surface - determined by the manufacturing processes Wide variations in surface characteristics Important reasons to consider surface Esthetic reason Safety Friction and wear Affects the mechanical integrity of a material Ability to assemble Better contact Surface Technology Relationship between processes and surface characteristics Defining the Characteristics of a surface Surface texture Altered layer – result of some processes Oxide film Substrate – grain structure Surface Texture Repetitive
    [Show full text]
  • A Pre-Metallization Guide to Lapping and Polishing Ceramic Substrates
    Tech Brief A Pre-metallization Guide to Lapping and Polishing Ceramic Substrates Accumet Tech Brief 2 A Pre-metallization Guide to Lapping, Polishing, and Grinding Ceramic Substrates INTRODUCTION Lapping, polishing, and grinding are machining techniques that refine a substrate to exact dimensions and tolerances for optimal circuit metallization during both thick and thin film technology procedures. Because the “as- fired”, or as delivered, condition of ceramic, fused silica, or titanate sub- strates are most often imperfect (wavy, pitted, bumpy, varied in thickness), one or more of these processes is employed to create the exact parallelism, camber, thickness, and surface finish needed. Designers working in high power, and/or high frequency microwave applications, for example, require their ceramic substrates to be consistently reliable and repeatable to meet the quality standards of their scrutinizing instrumentation, test and measure- ment, commercial communications, military radar, and aerospace customers. To do so, an optimal base substrate is key. In this brief our primary focus will be on lapping and polishing. Why Lap or Polish Ceramic Substrates? There are several justifications for lapping and/or polishing the ceramic substrates for your microelectronic circuits. Some of these considerations include achieving consistency from part to part, as well as meeting tolerance requirements for specific yield levels needed in thick or thin film device fabrication. For instance, the camber or flatness tolerance of a substrate may impact the resolution of the trace tolerance during the transfer of the photomask onto a substrate. Additionally, for high power and high frequen- cy applications, the substrate itself becomes a significant contributor to mechanical, thermal, and electrical behavior.
    [Show full text]