Materials Characterisation and Mechanism of Micro-Cutting in Ultra-Precision Diamond Turning (eBook)

Preface 5
Contents 7
Fundamentals 11
1 Single Point Diamond Turning Technology 12
Abstract 12
References 15
2 Factors Influencing Machined Surface Quality 16
Abstract 16
2.1 Machine Tools 16
2.2 Vibration in Machining 17
2.3 Cutting Conditions 18
2.4 Single Point Diamond Tools 20
2.5 Environmental Conditions 21
2.6 Workpiece Materials 22
2.7 Deformation Behaviour of Materials in Machining 24
References 26
3 Modelling and Simulation for Ultra-Precision Machining 30
Abstract 30
3.1 Analytical and Numerical Methods for Machining Process Modelling 30
3.1.1 Slip-Line Field Modelling of Machining 30
3.1.2 Molecular Dynamics Simulation of Machining 31
3.1.3 Quasicontinuum (QC) Method 32
3.1.4 Meshfree Method 33
3.1.5 Discrete Element Method 35
3.1.6 Finite Element Method 36
3.2 Models of Chip Formation and Shear Bands Theory 38
3.2.1 The Chip Formation Process and Models in Metal Cutting 38
3.2.2 Shear Band Formation and Chip Morphology 41
3.2.3 The Shear Angle Relationship 43
References 44
Materials Characterisation in Ultra-Precision Diamond Turning 50
4 Machinability of Single Crystals in Diamond Turning 51
Abstract 51
4.1 Key Aspects in Diamond Turning of Single Crystals 51
4.1.1 The Ultra-Precision Machine 51
4.1.2 Diamond Tools 51
4.1.3 Measurement of Surface Roughness 54
4.1.4 Measurement of Cutting Force 58
4.1.5 Work Materials and Cutting Conditions 58
4.2 Effect of Crystallography on Surface Roughness 60
4.2.1 Surface Features with Crystallographic Orientation 60
4.2.2 Surface Roughness Profiles Along Radial Sections 64
4.2.3 Degree of Roughness Anisotropy (DRA) 65
4.3 Variation of Cutting Force 67
4.3.1 Effect of Feed Rate on the Cutting Force 67
4.3.2 Effect of Depth of Cut on the Cutting Force 68
4.4 Observation on Chip Formation 69
References 76
5 Materials Deformation Behaviour and Characterisation 78
Abstract 78
5.1 Techniques for Materials Characterisation 78
5.1.1 X-ray Diffraction 78
5.1.2 Nano-indentation Measurements 80
5.1.3 Nanoscratch Testing 83
5.1.4 Transmission Electron Microscopy (TEM) 84
5.2 Characterisation of the Diamond-Turned Surface Layer 86
5.2.1 X-ray Diffraction Line Profile Analysis 86
5.2.2 Microhardness and Elastic Modulus of Machined Surface 86
5.2.3 Friction Coefficient 88
5.2.4 Dislocation Density and Structure of Diamond-Turned Surface Layers 89
5.3 Influences of Material Swelling upon Surface Roughness 96
5.3.1 Materials Swelling Effect 96
5.3.2 Characterisation Techniques 102
5.3.3 Formation of Surface Roughness in Machining 108
References 110
6 Material Electropulsing Treatment and Characterisation of Machinability 112
Abstract 112
6.1 Basics of Electropulsing Treatment 113
6.1.1 Development of Electropulsing Treatment 113
6.1.2 Theory of Electropulsing Treatment 113
6.2 Effect of Electropulsing Treatment on Microstructural Changes 119
6.2.1 Technical Aspects of Electropulsing Treatment 119
6.2.1.1 Static Electropulsing Treatment 120
6.2.1.2 Dynamic Electropulsing Treatment 122
6.2.2 Phase Transformation and Microstructural Changes 123
6.2.3 Dislocation Identity 134
6.2.4 Driving Forces for Phase Transformations 136
6.2.5 Electropulsing Kinetics 137
6.3 Machinability Enhancement by Electropulsing Treatment 138
References 151
7 Microplasticity Analysis for Materials Characterisation 153
Abstract 153
7.1 Shear Angle and Micro-Cutting Force Prediction 153
7.1.1 Microplasticity Model for Shear Angle Prediction 153
7.1.2 Texture Softening Factor 157
7.1.2.1 Selection of Active Set of Slip Systems 157
7.1.2.2 Determination of Texture Softening Factor 159
7.1.3 Criterion for Shear Angle Prediction 160
7.1.4 Prediction of Micro-Cutting Forces Variation 162
7.2 Variation in Shear Angle and Cutting Force 165
7.2.1 Shear Angle Predictions and Experimental Methods 166
7.2.2 Power Spectrum Analysis of Cutting Force 174
7.3 Microstructual Characterisation of Deformation Banding 181
7.3.1 Typical Cutting-Induced Shear Band 181
7.3.2 Orthogonal Cutting-Induced Kink Band 183
7.3.3 Cutting Induced Kinking Within the Sliding Region 185
References 190
Theory and Mechanism of Ultra-Precision Diamond Turning 192
8 Shear Bands in Ultra-Precision Diamond Turning 193
Abstract 193
8.1 Shear Band Theory for Deformation Processes in Machining 193
8.2 Regularly Spaced Shear Bands and Morphology of Serrated Chips 195
8.3 Finite Element Method Modelling for Elastic Strain-Induced Shear Bands 201
8.3.1 Characterisation of Elastic Strain-Induced Shear Bands 201
8.3.2 Finite Element Method Modelling 202
8.3.2.1 Setup of Finite Element Model 202
8.3.2.2 Simulation Results and Analysis 207
The Initiation of Shear Bands 209
The Propagation of Shear Bands 210
8.4 Analytical Model of Shear Band Formation and Influences 211
8.4.1 Onset of the Formation of Shear Bands 212
8.4.2 Formation of Shear Bands 214
8.4.3 An Analytical Model of Cyclic Fluctuation of Cutting Force 215
8.4.4 The Cyclic Fluctuation of the Displacement of the Tool Tip 217
8.5 Generalised Shear Angle Model 219
References 221
9 Tool-Tip Vibration at High Frequencies 223
Abstract 223
9.1 Identification of Tool-Tip Vibration by Power Spectrum Analysis 223
9.2 Characteristic Twin Peaks and Material Properties 225
9.3 Modelling of Tool-Tip Vibration 230
9.3.1 An Impact Model Without Damping 230
9.3.2 Non-harmonic Periodic Excitation with Process Damping Effect 233
9.4 Representative Measurement Method 238
9.4.1 Influence of Tool-Tip Vibration on the Machined Surface 238
9.4.1.1 Cutting Experiments 239
9.4.1.2 Identification of Tool-Tip Vibration on the Machined Surface Profile 241
9.4.2 Effect of Sample Locations on Surface Roughness 244
9.4.3 Effect of Sample Area Ratios and Representative Measurement 246
9.5 Modelling and Characterisation of Surface Roughness Generation 250
9.5.1 Surface Generation Model with Tool-Tip Vibration 250
9.5.2 Formation of Spiral Marks on the Machined Surface 252
9.5.3 Spatial Error on the Profile in the Feed Direction 254
References 254
10 Dynamic Modelling of Shear Band Formation and Tool-Tip Vibration in Ultra-Precision Diamond Turning 256
Abstract 256
10.1 A Transient Analysis for Shear Band Formation 259
10.2 Dynamic Model for Shear Band Formation 260
10.2.1 Dynamic Model 260
10.2.2 The Effect of Equivalent Cutting Velocity 262
10.2.3 Validation and Application 263
References 268