Non-traditional Micromachining Processes (eBook)

Preface 6
Acknowledgements 9
Contents 10
Editors and Contributors 12
1 Non-traditional Micromachining Processes: Opportunities and Challenges 15
Abstract 15
1.1 Introduction 16
1.1.1 Overview of Non-traditional Machining Processes 16
1.1.2 Need of Micromachining 18
1.1.2.1 Condition of Micromachining 19
1.1.2.2 Application Opportunities 20
1.1.3 Importance of Non-traditional Machining in Micromachining Domain 20
1.2 Classification of Non-traditional Micromachining Processes 21
1.2.1 Mechanical Micromachining 22
1.2.2 Thermal Micromachining 25
1.2.3 Chemical and Electrochemical Micromachining 26
1.2.4 Hybrid Micromachining 27
1.3 Introduction to Different Non-traditional Micromachining Processes 28
1.3.1 Micro Ultrasonic Machining (USM) 29
1.3.1.1 Mechanism of Material Removal 29
1.3.1.2 Opportunities 30
1.3.1.3 Challenges 31
1.3.1.4 Micro Engineering Applications 32
1.3.2 Micro Electro-Discharge Machining (EDM) 32
1.3.2.1 Mechanism of Material Removal 33
1.3.2.2 Opportunities 35
1.3.2.3 Challenges 35
1.3.2.4 Micro Engineering Applications 36
1.3.3 Micro Laser Beam Machining (LBM) 37
1.3.3.1 Mechanism of Material Removal 37
1.3.3.2 Opportunities 39
1.3.3.3 Challenges 39
1.3.3.4 Micro Engineering Applications 40
1.3.4 Micro Ion Beam Machining (IBM) 41
1.3.4.1 Mechanism of Material Removal 41
1.3.4.2 Opportunities 42
1.3.4.3 Challenges 43
1.3.4.4 Micro Engineering Applications 44
1.3.5 Micro Electron Beam Machining (EBM) 44
1.3.5.1 Mechanism of Material Removal 45
1.3.5.2 Opportunities 46
1.3.5.3 Challenges 47
1.3.5.4 Micro Engineering Applications 47
1.3.6 Micro Chemical Machining (CM) 48
1.3.6.1 Mechanism of Material Removal 48
1.3.6.2 Opportunities 49
1.3.6.3 Challenges 49
1.3.6.4 Micro Engineering Applications 50
1.3.7 Micro Electrochemical Machining (ECM) 50
1.3.7.1 Mechanism of Material Removal 51
1.3.7.2 Opportunities 52
1.3.7.3 Challenges 53
1.3.7.4 Micro Engineering Applications 53
1.4 Introduction to Various Hybrid Micromachining Processes 54
1.4.1 Electrochemical Grinding (ECG) 54
1.4.2 Electrochemical Discharge Micromachining 55
1.4.3 Abrasive Assisted Micromachining 57
1.4.4 Ultrasonic Assisted Micromachining 58
1.4.5 Laser Assisted Micromachining 59
1.5 Advanced Finishing Processes utilizing Non-traditional Machining 60
1.5.1 Abrasive Flow Finishing (AFF) 60
1.5.2 Chemo Mechanical Polishing (CMP) 61
1.5.3 Elastic Emission Machining (EEM) 62
1.5.4 Magnetic Abrasive Finishing (MAF) 63
1.6 Conclusions 64
References 65
2 Recent Advancement on Ultrasonic Micro Machining (USMM) Process 74
Abstract 74
2.1 Introduction 75
2.2 Fundamentals of Ultrasonic Machining (USM) Process 75
2.2.1 Background of USM 76
2.2.2 Process Development of USM 76
2.2.3 Types of Machining Operation 77
2.3 Fundamentals of Ultrasonic Micro Machining (USMM) Process 78
2.3.1 Background of USMM 78
2.3.2 Process Development of USMM 79
2.3.3 Types of Ultrasonic Micro Machining Operation 79
2.4 Principle of Material Removal in Ultrasonic Micro Machining (USMM) Process 81
2.4.1 Mechanism of Material Removal 82
2.4.1.1 Formation of Cracks in Brittle Materials Due to Indentation 84
2.4.2 Models on Material Removal Mechanism 86
2.5 Basic Element of Ultrasonic Micro Machining Set up 89
2.5.1 The Ultrasonic Power Supply 89
2.5.2 Oscillating System 90
2.5.3 Horn 91
2.5.4 Coupler 91
2.5.5 The Mechanism of Tool Feeding 91
2.5.6 The Abrasive Slurry Supply System Unit 92
2.6 Design and Developments of Microtools for USMM 92
2.7 Parametric Influences of Various Responses of Ultrasonic Micro Machining (USMM) 94
2.7.1 Influences of Process Parameters on Material Removal Rate 95
2.7.2 Influences of Process Parameters on Tool Wear 95
2.7.3 Influences of Process Parameters on Surface Finish 95
2.8 Development of Micro Feature Using USMM 96
2.9 Advantages, Limitations, and Applications of USMM 100
2.10 Scope of Advanced Research on USMM 101
2.11 Summary 101
References 102
3 Electrical Discharge Micro-hole Machining Process of Ti–6Al–4V: Improvement of Accuracy and Performance 105
Abstract 105
3.1 Introduction 106
3.2 Brief Overview of EDM and Micro-EDM 106
3.3 Micro-EDM System Details 109
3.4 Pulse Generators for Micro-EDM 110
3.5 Control Parameters of Micro-EDM 110
3.5.1 Electrical Process Parameters 111
3.5.2 Nonelectrical Process Parameters 112
3.5.3 Gap Control and Motion Parameters 113
3.6 Micro-EDM Performance Measurements 115
3.7 Varieties of Micro-EDM Processes 116
3.7.1 Micro-EDM Drilling 116
3.7.2 Micro Wire-EDM 117
3.7.3 Micro-EDM Milling 118
3.7.4 Dry and Near-Dry Micro-EDM 119
3.7.5 Planetary or Orbital Micro-EDM 119
3.7.6 Reverse Micro-EDM 120
3.7.7 Micro Electro-discharge Grinding 120
3.8 Applications of Titanium and Its Alloys 123
3.9 Brief Background of Machining Ti–6Al–4V in Micro-EDM 123
3.10 Innovative Machining Strategies for Improving Micro-EDM 126
3.10.1 Ultrasonic Vibration Assisted Micro-EDM 126
3.10.2 Utilization of Non-hydrocarbon Dielectrics 128
3.10.3 Abrasive Mixed Dielectric in Micro-EDM 136
3.10.4 Rotation of Micro-tool Electrode 143
3.10.5 Reversing Polarity of Electrodes 146
3.11 Conclusions 152
Acknowledgements 153
References 153
4 Advancements in Micro Wire-cut Electrical Discharge Machining 157
Abstract 157
4.1 Introduction 158
4.2 Working Principle 158
4.2.1 Mechanism of Sparking and Material Removal 160
4.2.2 Work Material 160
4.2.3 Dielectric Fluids 161
4.2.4 Wire Electrode 161
4.2.5 Wire Tool Failure and Its Prevention 162
4.3 Micro WEDM Machine 163
4.3.1 Taper Cutting System in MWEDM 164
4.3.2 Trim Cutting Features in MWEDM 164
4.3.3 Micro WEDM Process Parameters 165
4.4 Micro WEDM Circuits and Operating Principles 165
4.4.1 R–C Relaxation Circuit 166
4.4.1.1 Current in the Charging Circuit 167
4.4.1.2 Current in the Discharging Circuit 168
4.4.1.3 R-L-C Discharging Circuit 169
4.4.1.4 Frequency and MRR in R-C Circuit 169
4.4.2 High Frequency Electronic Circuit 170
4.5 Pulse Types and Pulse Discrimination 171
4.6 Wire Vibration in Micro WEDM 172
4.7 Wire Lag in Micro WEDM 177
4.7.1 Equation of the Traced Path of the Wire for Right Angle Corner Cutting 179
4.8 The Kerf Produced in Micro WEDM 180
4.9 Wire Transportation System in MWEDM 181
4.10 Process Performances in MWEDM 184
4.10.1 White Layer 184
4.10.2 Surface Roughness and Machining Accuracy 186
4.10.3 Assisted Vibration in MWEDM 186
4.11 Applicability of Micro WEDM 188
References 190
5 Laser Micro-turning Process of Aluminium Oxide Ceramic Using Pulsed Nd:YAG Laser 191
Abstract 191
5.1 Introduction 192
5.2 Need for Micro-machining of Advanced Ceramic Materials 193
5.3 Suitability of Nd:YAG Laser for Micromachining 193
5.4 Laser Beam Micro-machining Processes 194
5.4.1 Laser Micro-drilling 195
5.4.2 Laser Micro-cutting 195
5.4.3 Laser Micro-grooving 195
5.4.4 Laser Micro-turning 196
5.5 Difficulties of Micro-turning of Ceramic Materials 197
5.6 Process Mechanism of Laser Micro-turning 198
5.7 Development of Laser Micro-turning Set Up 200
5.8 Experimentation and Measurement Schemes 203
5.9 Results and Discussion 204
5.9.1 Parametric Studies, Modeling and Optimization of Laser Micro-turning in RSM Approach 206
5.9.2 Influence of Overlap Factors on Machining Criteria 215
5.9.3 Influence of Laser Defocusing Conditions on Machining Criteria 220
5.9.4 Comparative Study of Focused and Various Defocus Conditions Machining 225
5.9.5 Microscopic Observations of Laser Micro-turning Surfaces 231
5.10 Conclusions 236
Acknowledgements 237
References 237
6 Fiber Laser Micro-machining of Engineering Materials 239
Abstract 239
6.1 Introduction 239
6.1.1 Fundamentals of Fiber Laser Generation 240
6.1.2 Different Types of Fiber Laser Systems 243
6.1.3 Importance and Advantages of Fiber Laser in Micro-machining Domain 244
6.1.3.1 Superior Beam Quality 244
6.1.3.2 High Wall Plug Efficiency and Reduction of Operating Cost 245
6.1.3.3 High Reliability and Low Maintenance 245
6.1.3.4 Ease of Beam Delivery 245
6.1.4 Basic Principle of Fiber Laser Micro-machining Process 246
6.1.5 Applications of Fiber Laser in the Micro-machining Domain 247
6.2 Different Units of Diode Pumped Fiber Laser Micro-machining System 248
6.2.1 Power Supply Unit 248
6.2.2 Laser Head 248
6.2.3 Collimator 249
6.2.4 Beam Bender 249
6.2.5 Beam Delivery Unit and Focusing Lens 250
6.2.6 Assist Gas Supply Unit 250
6.2.7 CNC Controller for X–Y–Z Movement 250
6.3 Various Fiber Laser Micro-machining Operations on Engineering Materials 251
6.3.1 Micro-cutting 252
6.3.1.1 Stent Cutting 253
6.3.2 Micro-grooving 254
6.3.3 Micro-channeling 255
6.3.4 Micro-drilling 256
6.3.5 Engraving 258
6.3.6 Micro-turning 259
6.3.7 Marking 259
6.4 Recent Developments and Future Scope of Fiber Laser Micro-machining 260
6.5 Summary 261
Acknowledgments 262
References 262
7 Laser Beam Micro-cutting 265
Abstract 265
7.1 Introduction 265
7.2 Physics of Laser Material Processing 266
7.3 Laser Beam Cutting 269
7.3.1 Different Types of Laser Beam Cutting 270
7.3.1.1 Laser Evaporative Cutting 270
7.3.1.2 Controlled Fracture Technique 271
7.3.1.3 Laser Fusion Cutting 271
7.3.1.4 Reactive Fusion Cutting 272
7.3.1.5 Laser Cold Cutting 273
7.3.1.6 Laser Beam Microcutting 273
7.3.1.7 Laser Cutting at Different Assisted Medium 274
7.3.2 Process Characteristics 274
7.3.2.1 Laser Fluence 274
7.3.2.2 Mode of Operations 274
7.3.2.3 Wavelength 275
7.3.2.4 Beam Delivery System 275
7.3.2.5 Assist Gas 275
7.3.3 Quality Aspect 276
7.3.3.1 Dross 276
7.3.3.2 Striation 276
7.4 Application of Laser Beam Machining 278
7.5 A Case Study on Laser Beam Micro Cutting of Inconel 625 Superalloy 278
7.5.1 Machining Conditions 278
7.5.2 Results and Discussion 280
7.5.3 Determination of Optimal Parameter Settings 283
7.5.4 Conclusion of Case Study 284
7.6 Summary 284
Acknowledgements 284
References 285
8 Electrochemical Micromachining (EMM): Fundamentals and Applications 287
Abstract 287
8.1 Introduction 288
8.2 Electrochemical Machining (ECM): Basic Process 288
8.3 Electrochemical Micromachining (EMM): Focusing Area 290
8.3.1 ECM and EMM 291
8.3.2 Advantages and Limitations of EMM 292
8.3.3 Role of EMM in Micromachining 293
8.4 Fundamentals of EMM 293
8.4.1 Electrochemistry of EMM 294
8.4.1.1 Cathode Reactions 295
8.4.1.2 Anode Reactions 296
8.4.2 Faraday’s Law of Electrolysis 297
8.4.3 Electrical Double Layer 298
8.4.4 Equivalent Electrical Circuit 299
8.5 Material Removal Mechanism in EMM 301
8.6 Different Types of EMM 304
8.6.1 Through-Mask EMM 304
8.6.2 Maskless EMM 306
8.7 Important Process Parameters of EMM 307
8.7.1 Nature of Power Supply 308
8.7.2 Microtools for EMM 309
8.7.3 Electrolytes for EMM 311
8.7.4 Mechanical Capabilities of Setup 315
8.8 EMM Setup Development 315
8.8.1 Need of Setup Development 315
8.8.2 Challenges in Setup Development 316
8.9 EMM Subsystems 317
8.9.1 Mechanical Machining Unit 317
8.9.2 Power Supply Unit 319
8.9.3 Microtool Vibration Unit 320
8.9.4 Machining Chamber 320
8.9.5 Process Monitoring and Control 321
8.10 Accuracy Improvement Techniques in EMM 321
8.10.1 Geometry of Microtools 323
8.10.2 Microtool Insulation 324
8.10.3 Electrolyte Circulation 326
8.10.4 Microtool Movement Strategy 328
8.10.5 Micro-sparks Phenomena in EMM 328
8.11 Applications of EMM 329
8.11.1 Machining Applications 329
8.11.1.1 Micronozzles 329
8.11.1.2 Microholes, Slots, and Channels 330
8.11.1.3 Three-Dimensional Micro Features 331
8.11.1.4 Micropins or Microtools 332
8.11.1.5 Disc Shape Microtools 332
8.11.2 Finishing Applications 333
8.11.2.1 Finishing of Print Bands 334
8.11.2.2 Edge Finishing 334
8.11.3 Surface Engineering Applications 335
8.11.3.1 Generation of Micro Pattern on Stainless Steel 335
8.11.3.2 Surface Structuring of Titanium by EMM 336
8.11.3.3 Surface Structuring for Biomedical Implants 336
8.12 Recent Advances in EMM 337
8.12.1 Fabrication of Micro Features for MEMS 337
8.12.2 Solid-State EMM 339
8.12.3 Wire-EMM 340
8.12.4 Nanofabrication by EMM 342
8.13 General Conclusions 344
References 344
9 Electrochemical Micromachining of Titanium and Its Alloys 348
Abstract 348
9.1 Introduction 349
9.2 Electrochemical Micromachining (EMM) 350
9.3 Titanium and Its Alloys: Types and Usage 351
9.3.1 Challenges in Titanium Machining 354
9.3.2 Machining of Titanium by Conventional and Non conventional Processes 354
9.4 Machining of Titanium by Anodic Dissolution 355
9.4.1 Difficulties Encountered with Anodic Dissolution of Titanium in Microscopic Domain 356
9.4.2 EMM as a Potential Process for Titanium Micro Machining 357
9.5 Effect of Various EMM Process Parameters on Maskless EMM of Titanium 358
9.5.1 Role of Electrolyte 358
9.5.2 Effect of Machining Voltage 360
9.5.3 Effect of Pulse Duty Ratio 362
9.5.4 Effect of Pulse Frequency 363
9.5.5 Effect of Micro Tool Vibration 365
9.6 Through Mask EMM of Titanium 366
9.7 Micro Features Generation on Titanium 369
9.7.1 Suitable Range of EMM Process Parameters for Fabrication of Micro Features on Titanium 372
9.7.2 Potential Applications of Titanium Micro Features 374
9.8 Future Scope and Challenges in Titanium Micromachining 374
9.9 Conclusions 375
References 375
10 Electrochemical Discharge Micro-machining of Engineering Materials 377
Abstract 377
10.1 Introduction 378
10.1.1 Fundamentals of Electrochemical Discharge Micro-machining (Micro-ECDM) Process 378
10.1.2 Need of Electrochemical Discharge Micro-machining of Engineering Materials 380
10.1.3 Problems in Electrochemical Discharge Micro-machining of Engineering Materials 381
10.1.4 Possibilities and Applications of Electrochemical Discharge Micro-machining 383
10.2 Electrochemical Discharge Micro-machining System Details 386
10.2.1 Machining Chamber Details 386
10.2.2 Job Holding Unit 387
10.2.3 Tool Holding and Guiding Unit 388
10.2.4 Micro-tool Development for Micro-ECDM 389
10.2.5 Auxiliary Electrode Unit 389
10.2.6 Inter-electrode Gap Control Unit 389
10.2.7 Feeding Unit 390
10.2.8 Electrolyte Supply Unit 390
10.2.9 Electrical Power Supply Unit 391
10.2.10 Specification Details of the Micro-ECDM System 392
10.3 Parametric Studies on Electrochemical Discharge Micro-machining of Engineering Materials 393
10.3.1 Micro-drilling 394
10.3.2 Micro-cutting 397
10.4 Challenging Areas of Electrochemical Discharge Micro-machining 400
10.5 Summary 400
Acknowledgements 400
References 401
11 Travelling Wire Electrochemical Spark Machining: An Overview 403
Abstract 403
11.1 Introduction 403
11.2 Literature Review 405
11.3 Experimental Investigation 411
11.3.1 Designed and Fabrication of TWECSM 411
11.3.2 Experimental Planning 411
11.3.3 Results and Discussions 413
11.3.4 Scanning Electron Micrographs 415
11.3.5 Mathematical Modelling 417
11.4 Conclusions and Future Scope 420
References 420
Index 422