Application of Lasers in Manufacturing (eBook)

Dr. Uday Shanker Dixit received his B.E. degree in Mechanical Engineering from the erstwhile University of Roorkee (now the Indian Institute of Technology Roorkee) in 1987, his M.Tech. degree in Mechanical Engineering from the Indian Institute of Technology Kanpur in 1993, and his Ph.D. in Mechanical Engineering from the IIT Kanpur in 1998. He has worked in two industries—HMT, Pinjore and INDOMAG Steel Technology, New Delhi, where his main responsibility was designing various machines. Dr. Dixit joined the Department of Mechanical Engineering, Indian Institute of Technology Guwahati, in 1998, where he is currently a professor. He was also Officiating Director of the Central Institute of Technology, Kokrajhar from February 2014 to May 2015. Dr. Dixit has been actively engaged in research in various areas of design and manufacturing for the past 25 years. He has authored/co-authored 75 journal papers, 91 conference papers, 20 book chapters and 6 books on mechanical engineering. He has also co-edited 3 books related to manufacturing. Out of these 9 books, 6 have been published by Springer. He has guest-edited 10 special issues for journals and is currently an associated editor of the Journal of Institution of Engineers (India), Series C. Dr. Joshi received his Ph.D. in "Intelligent process modeling and optimization of electric discharge machining" from the Indian Institute of Technology (IIT) Bombay, India in 2010. Currently, he is working as an Associate Professor at the Department of Mechanical Engineering, Indian Institute of Technology (IIT) Guwahati, India. His research interests include laser-based manufacturing, ultra-precision machining, computer-aided design and manufacturing (CAD/CAM), and manufacturing process modeling & optimization. Dr. Joshi has published about 45 papers in journals and conferences of national/international repute, and has edited a book on "Laser-based manufacturing" (Springer) along with Prof. U. S. Dixit, IIT Guwahati. He has also authored four book chapters in books published at the international level.Dr. J. Paulo Davim received his Ph.D. in Mechanical Engineering from the University of Porto in 1997, the Aggregate title from the University of Coimbra in 2005, and a DSc from London Metropolitan University in 2013. Currently, he is a professor at the Department of Mechanical Engineering of the University of Aveiro. He has over 30 years of teaching and research experience in manufacturing, materials, and mechanical engineering with a special focus on machining and tribology.  He has also started taking an interest in management/industrial engineering and higher education for sustainability. He has worked as an evaluator of projects for international research agencies as well as an examiner of Ph.D. thesis for many universities. He is the editor-in-chief of several international journals, guest editor of journals, book editor, book series editor, and scientific advisory for many international journals and conferences. Presently, he is an editorial board member of 25 international journals and serves as reviewer for more than 80 prestigious Web of Science journals. In addition, he has also published, as author and co-author, more than 10 books, 80 book chapters, and 400 articles in journals and for conferences.  

Preface 6
Editorial Acknowledgements 8
About the AIMTDR Conference 9
Mission, Vision, Challenges and Direction of AIMTDR Conference 10
AIMTDR 2016 Conference: Objectives and Organization 13
Contents 15
About the Editors 17
1 Comparative Investigation on the Effects of Laser Annealing and Laser Shock Peening on the As-Manufactured Ni–Ti Shape Memory Alloy Structures Developed by Laser Additive Manufacturing 19
Abstract 19
1 Introduction 20
2 Numerical Simulation of Laser Annealing and Laser Shock Peening 21
2.1 Governing Equation 22
2.2 Boundary Conditions and Associated Simplifications 22
2.3 Numerical Computation 24
3 Experimental Procedure 25
3.1 Laser Shock Peening 26
3.2 Laser Annealing 27
4 Results and Discussion 29
4.1 Scanning Electron Microscopy (SEM) 30
4.2 Microstructure 31
4.3 Atomic Force Microscopy (AFM) 32
4.4 Microhardness 33
4.5 X-ray Diffraction (XRD) 33
4.6 Differential Scanning Calorimetry (DSC) 35
5 Influence of Laser Annealing and Laser Shock Peening 36
6 Conclusion 36
Acknowledgements 36
References 37
2 A Numerical Investigation into the Effect of Forced Convection Cooling on the Performance of Multi-scan Laser Bending Process 39
Abstract 39
1 Introduction 39
2 Numerical Modeling and Simulation of Forced Cooling Based Multi-scan Laser Bending 41
2.1 Worksheet Details 42
2.2 Heat Flux Model 42
2.3 Thermal Analysis 42
2.4 Mechanical Analysis 43
2.5 Meshing and Solution Methodology 43
3 Results and Discussion 44
3.1 Bending Mechanism 44
3.2 Effect of Process Parameters on Bend Angle 48
3.2.1 Effect of Laser Power 49
3.2.2 Effect of Scan Speed 51
3.2.3 Effect of Number of Laser Scans 52
3.3 Incremental Variation in Bend Angle 54
3.4 Edge Effect 56
4 Conclusions 60
References 60
3 Experimental Study of Fiber Laser Weldments of 5 mm Thick Ti–6Al–4V Alloy 62
Abstract 62
1 Introduction 63
2 Materials and Experimental Details 68
2.1 Experimentation 70
2.2 Metallographic Specimen Preparation 72
3 Results and Discussion 72
3.1 EDX Analysis of the Joint 73
3.2 Weld Bead Appearance and Its Shape 73
3.3 Penetration Depth and Width of FZUP 74
3.4 Effect on HAZ Size 76
3.5 Microstructural Analysis of Weldment 78
3.6 Hardness 81
4 Conclusion 82
References 83
4 Laser Microwelding of Titanium Alloy 85
Abstract 85
1 Introduction 86
2 Experimental Investigation 89
2.1 Nondimensional Heat Input Index 91
2.2 Weld Joint Characteristics 92
2.3 Mechanical Properties 94
2.4 Distortion Analysis 96
3 Thermomechanical Modeling and Simulation 97
3.1 Conduction Mode Heat Transfer Analysis 98
3.1.1 Governing Equation and Boundary Conditions 99
3.2 Mechanical Model 100
3.3 Model Geometry and Material Properties 101
3.4 Calibration of Numerical Model 102
3.4.1 Selection of Mesh Size 102
3.4.2 Selection of Time Step 102
4 Simulation of Laser Microwelding Process 103
5 Comparison of Laser and Plasma Microwelding Processes 105
6 Conclusions 108
Acknowledgements 109
References 109
5 Thermal Stress Analysis in Selective Laser Melting of Ti6Al4V Powder Layer 111
Abstract 111
1 Introduction 112
2 Origin of Residual Stresses 116
3 Model Description 117
3.1 Model Assumptions 117
3.2 Thermal Model 118
3.2.1 Energy Conservation Equation 118
3.2.2 Momentum Conservation Equation 119
3.3 Mechanical Model 120
4 Results and Discussion 120
5 Conclusions 125
References 125
6 Laser Micromachining of Semiconductor Materials 127
Abstract 127
1 Introduction 127
2 Techniques for Producing Short Pulses 130
2.1 Gain Switching 130
2.2 Q-Switching 130
2.3 Mode Locking 131
2.4 Chirped Pulse Amplification Technique 132
3 Laser Ablation Mechanism 133
4 Experimental Investigation 135
4.1 Case Study I: Making of Holes in Silicon Wafer (n-Type) 136
4.1.1 Results and Discussion 136
4.2 Case Study II: Making of Micro-channels in silicon wafer 140
4.2.1 Results and Discussion 140
5 Conclusions 148
Acknowledgements 156
References 156
7 An Insight into Laser-Assisted Jet Electrochemical Machining Process 158
Abstract 158
1 Introduction 159
1.1 Electrochemical Machining (ECM) Process 160
1.1.1 ECM Mechanism and MRR 161
2 Laser-Assisted Jet Electrochemical Machining (LAJECM) 166
2.1 Material Removal Mechanism 167
2.2 Theoretical Energy Approach 170
3 Laser-Assisted Jet Electrochemical Machining Setup and Working 172
4 Design and Fabrication 173
5 Experimental Planning 173
6 Results and Discussions 176
6.1 Effect of Different Parameters Against Different Response Characteristics During Machining of EN-31 Steel 177
6.1.1 Effect of Supply Voltage (volt) on MRR (mg/min) 177
6.1.2 Effect of Inter-electrode Gap on MRR (mg/min) 178
6.1.3 Effect of Electrolyte Concentration on Taper (radians) 179
6.2 Optimization of Machining Characteristics 179
6.3 Mathematical Model for Different Response Characteristics 184
7 Conclusions 189
References 190
8 Nd:YAG Laser Cutting of Ni-Based Superalloy Thin Sheet: Experimental Modeling and Process Optimization 193
Abstract 193
1 Introduction 194
2 Experimentation 198
3 Modeling Methodology 200
4 Optimization Methodology 202
4.1 Single-Objective Optimization Approach: ANN-GA 203
4.2 Multi-objective Optimization Approach: TM-GRA 204
5 Results and Discussion 207
5.1 Modeling of TKW, BKW, and TKD Using ANN 207
5.1.1 Theoretical Validation of Models 209
5.1.2 Experimental Validation of Models 210
5.2 Single-Objective Optimization of the Process Using ANN-GA 212
5.3 Multi-objective Optimization of the Process Using TM-GRA 216
6 Conclusions 219
References 219
9 Experimental Investigations into Underwater Laser Transmission Micro-channeling on PMMA 222
Abstract 222
1 Introduction 223
2 Importance of Micro-channeling of PMMA and Its Application 224
3 Nd:YAG Laser Beam Machining System 226
4 Need of Laser Beam Machining Process at Wet Environment 228
5 Laser Transmission Cutting of PMMA in Partially Submerged Condition 229
5.1 Physical Characteristics of Workpiece Specimen 229
6 Experimentation 230
6.1 XRD Test of PMMA and Absorbent Material 232
7 Procedural Steps for Measurement of Responses 234
8 Experimental Result and Discussion 234
8.1 ANOVA Analysis for HAZ Width 237
8.2 Effect of Process Parameter on HAZ Width 237
9 Single-Objective Optimization 240
10 Confirmatory Experiments 240
11 Conclusion 241
References 241
10 Sensitivity Analysis of Submerged Laser Beam Cutting on Inconel 625 Superalloy 243
Abstract 243
1 Introduction 244
2 Laser Beam Cutting 245
2.1 Laser–Matter Interaction 245
2.2 Different Types of Laser Beam Cutting 248
2.2.1 Laser Fusion Cutting 248
2.2.2 Laser Oxidation Cutting 248
2.2.3 Laser Evaporative Cutting 249
2.2.4 Laser Scribing 250
2.2.5 Controlled Fracture Technique 250
2.2.6 Laser Micro-machining 251
2.3 Quality Aspect 252
2.3.1 Heat-Affected Zone (HAZ) 252
2.4 Submerged Laser Beam Cutting 252
2.5 Application of Laser Cutting Technique 253
3 Experimental Setup 253
3.1 Principle of Pulsed Nd:YAG Laser 253
3.2 Workpiece Selection 253
3.2.1 Underwater Workpiece Holding Unit 254
3.3 Selection of Process Variable Range and Machining Characteristics 254
3.4 Design of Experiments 256
4 Experimental Results and Observation 256
5 Sensitivity Analysis 256
6 ANOVA Analysis 261
7 Conclusion of Case Study 263
8 Summary 263
Acknowledgements 263
References 263