Cover......Page 1
Half Title......Page 2
Title Page......Page 4
Copyright Page......Page 5
Table of Contents......Page 6
Acknowledgements......Page 8
Editors......Page 10
Contributors......Page 12
1.1 Introduction to Additive Manufacturing......Page 16
1.2.1 General Terms......Page 19
1.2.3 Other Terms......Page 20
1.3 Towards Precision Additive Manufacturing......Page 21
References......Page 23
2.1 Introduction......Page 26
2.2 Topology Optimisation......Page 29
2.2.1 Density-Based TO Method......Page 30
2.2.1.1 Problem Formulation......Page 31
2.2.1.2 Sensitivity Analysis......Page 32
2.2.1.3 Filtering Techniques......Page 33
2.3 Topology Optimisation for Precision Metal AM......Page 34
2.3.1.1 Two-Dimensional Overhang Control......Page 35
2.3.1.2 3D Overhang Control......Page 37
2.3.1.3 Support Inclusion......Page 38
2.3.2 TO Methods for Preventing Overheating in Precision AM Parts......Page 39
2.3.3 Towards TO Methods for Avoiding Distortion in Precision AM Parts......Page 43
2.4 Challenges and Outlook......Page 45
References......Page 46
Chapter 3 Development of Precision Additive Manufacturing Processes......Page 50
3.2 State of the Art and Insight into Precision Process Development......Page 51
3.3 Setting Priorities......Page 53
3.4.1 Laser-Related Process Parameters......Page 54
3.4.3 Powder-Related Process Parameters......Page 57
3.4.5 Combined Processing Parameters......Page 58
3.5.2 Dimensional Accuracy......Page 59
3.5.3 Surface Texture......Page 61
3.5.7 System-Wide Performance Indicators......Page 62
3.6 Data-Driven Process Improvement......Page 63
3.6.1 Design of Experiments......Page 65
3.6.2 Modelling of Process Performance (Quantifying Input/Output Process Relationships)......Page 66
3.6.2.2 Artificial Neural Network Modelling......Page 67
3.6.3 Process Optimisation......Page 70
3.7 Precision Processes in the Domain of Industry 4.0......Page 72
3.7.2 Artificial Intelligence and Decision-Making Systems for Digital Quality Control......Page 73
3.8 Future Perspectives for Precision AM Processes......Page 74
References......Page 76
4.1 Introduction......Page 84
4.2.1 The Physics of Laser Powder Bed Fusion......Page 85
4.2.2 Challenges of Length and Time Scales......Page 87
4.3.1 Understanding Thermal History, Residual Stresses and Distortions......Page 89
4.3.3 Full-Scale, Reduced-Order and Effective Models......Page 90
4.4.1 Powder Bed Formation and Representation......Page 93
4.4.2 Simulating LaserโMaterial Interactions......Page 94
4.4.3 Melt-Pool Dynamics in a Powder Bed......Page 96
4.4.4 Evolution of Porosity during AM......Page 97
4.4.5 Surfaces and Solidification during AM......Page 100
4.5.2 Metallurgical Modelling Techniques......Page 101
4.5.3 Revisiting Solidification during AM from a Metallurgical Perspective......Page 102
4.5.4 Need for Heat-Treatment as Post-Process......Page 103
4.6.1 Data-Based Models......Page 104
4.6.2 Digital and Physical Design of Experiments......Page 105
4.6.3 GIGO Approach to Model Calibration......Page 106
4.7 Concluding Remarks and Future Outlook......Page 107
References......Page 108
Chapter 5 Secondary Finishing Operations......Page 112
5.1 Introduction......Page 113
5.3.1.1 Fatigue Applications......Page 114
5.3.2 Examples of AM Surfaces......Page 117
5.4 Specification Standards in Secondary Finishing......Page 119
5.5.1.1 Challenges of Surface Topography......Page 122
5.5.2 Geometrical Challenges for Finishing Operations......Page 123
5.5.4 Finishing Challenges for AM in Precision Applications......Page 125
5.6 Available Secondary Finishing Processes......Page 126
5.6.1 Conventional Machining Methods......Page 127
5.6.2 Non-Conventional Machining Methods......Page 128
5.6.3.2 Hybrid Mass Finishing and Chemical......Page 130
5.6.3.5 Mass Finishing Targeted at AM......Page 131
5.7 What Processes Are Appropriate for AM?......Page 132
5.7.1 Narrow Channels......Page 135
5.7.7 Thin Features......Page 136
5.9 How to Impact AM Design for Finishing......Page 137
5.10.1 New Processes and Technologies in Development......Page 138
5.10.1.3 Automation and Modelling......Page 139
5.10.2.2 Hybrid Technologies......Page 140
5.10.2.5 Automation and Targeted Finishing......Page 141
References......Page 142
Chapter 6 Standards in Additive Manufacturing......Page 148
6.1 Introduction......Page 149
6.3 AM Powder Feedstock Characterisation Standards......Page 153
6.3.1 Feedstock Sampling Strategy......Page 154
6.3.2 Particle Size Determination and Distribution......Page 156
6.3.3 Morphology Characterisation Methods......Page 157
6.3.5 Thermal Characterisation......Page 158
6.3.6 Density Determination......Page 159
6.5 Part Verification......Page 160
6.5.3 Hardness Measurement......Page 161
6.6 Surface Standards......Page 162
6.8.1 Current Standards......Page 163
6.8.2 Welding Standards......Page 164
6.8.3 Casting Standards......Page 165
6.9 Future and Planned Standards Activities......Page 166
References......Page 167
7.1 Introduction......Page 172
7.2 A Primer in Manufacturing Cost Modelling......Page 174
7.3 Developing an AM Costing Framework......Page 175
7.4 Specifying a Simple Cost Model for Precision AM......Page 177
7.5.1 Indirect Cost Rates......Page 179
7.5.2 Capacity Utilisation......Page 180
7.5.4 Relationship between Failure Parameters and Costs of Inspection......Page 181
7.6 Summary and Additional Perspectives......Page 182
References......Page 183
8.1 Introduction......Page 186
8.1.1 Definitions......Page 187
8.1.3 Background......Page 189
8.2.1 Key Contributions to 3D Test Artefacts......Page 191
8.2.2 Strengths and Challenges of 3D Test Artefacts......Page 193
8.2.3 Considerations for 3D Test Artefact Design......Page 194
8.3 Component Testing......Page 195
8.3.2 Strengths and Challenges of Component Testing......Page 196
8.3.3 General Principles of Component Testing......Page 197
8.3.4 Z-Axis......Page 198
8.3.5 Directed Energy Deposition Machine Error Motions......Page 199
8.3.7 Energy Beam Diagnostics......Page 200
8.3.8 Non-Geometric Measurements......Page 202
8.4.1 Strengths and Challenges of 2D Test Artefacts......Page 203
8.4.3 Considerations for Designing a 2D Test Artefact......Page 204
Disclaimer......Page 206
References......Page 207
9.1 Introduction......Page 210
9.2 Typical Defects in AM......Page 211
9.3 NDE Challenges in AM......Page 213
9.4 NDE Methods โ Advantages and Limitations......Page 216
9.5 NDE Standardisation for AM......Page 217
9.6 NDE for Qualification in AM......Page 225
9.6.1 Post-Process Inspection......Page 228
9.6.2 In-Process Inspection......Page 234
9.7 NDE Reliability in AM......Page 236
9.7.1.2 Mathematical Simulation of PoD Curves......Page 241
9.7.2 Estimation of Experimental PoD......Page 242
9.8 Current PoD Performed in AM......Page 243
9.9 Conclusions and Future Research......Page 244
Acknowledgements......Page 245
References......Page 246
10.1 Introduction......Page 252
10.2.1 Surface and Coordinate Metrology Terms and Definitions......Page 254
10.2.2 General Metrology Terms and Definitions......Page 255
10.3.1 Coordinate Metrology System Configurations......Page 256
10.3.2 Coordinate Metrology Software......Page 258
10.3.3 CMS Alignment......Page 259
10.3.4 CMS Errors......Page 260
10.4.1 Contact Probe Types......Page 261
10.4.2 Contact Probe Errors......Page 263
10.4.3 AM Roughness Issues with Contact Probing......Page 264
10.5 Optical Methods......Page 265
10.5.1 Vision Systems......Page 267
10.5.2.1 Time-of-Flight Method......Page 268
10.5.2.2 Laser Triangulation......Page 269
10.5.3.1 Digital Fringe Projection Technique......Page 271
10.5.3.2 Photogrammetry......Page 274
10.6.1 Current Performance Evaluation Framework......Page 276
10.6.2 Current Uncertainty Framework......Page 277
10.7 Current Research and Future Look......Page 279
References......Page 280
Chapter 11 Post-Process Surface Metrology......Page 284
11.1.1 The Nature of Metal AM Surfaces......Page 285
11.2.1 Surface Metrology Terms and Definitions......Page 286
11.2.2.3 Other Standards......Page 289
11.3.1.1 Profile and Areal Topography Measurement Systems......Page 291
11.3.1.2 Three-Axis And Five-Axis Topography Measurement Systems......Page 292
11.3.2.1 Height Maps......Page 293
11.3.2.2 Triangle Meshes......Page 295
11.3.3.2 Stylus Instruments โ Uses in AM......Page 296
11.3.4.1 Optical Methods for Topography Measurement โ Basics......Page 298
11.3.4.2 Optical Measurement of Surface Topography โ Uses in AM......Page 299
11.3.5.1 Scanning Electron Microscopy โ Basics......Page 302
11.3.5.2 Scanning Electron Microscopy โ Uses in AM......Page 303
11.3.5.4 X-Ray Computed Tomography โ Uses in AM......Page 304
11.3.6 Performance Comparison of Non-Contact Methods......Page 305
11.3.7.1 Scanning Probe Microscopy โ Basics......Page 306
11.4.1 Topography Data Pre-Processing......Page 307
11.4.2 Topography Data Pre-Processing for AM Surfaces......Page 308
11.4.3 Surface Texture Parameters......Page 310
11.4.3.2 Areal Height Parameters......Page 311
11.4.3.3 Areal Height Parameters โ Uses in AM......Page 312
11.4.3.4 The Areal Material Ratio Curve and Related Parameters......Page 313
11.4.3.5 The Areal Material Ratio Curve and Related Parameters โ Uses in AM......Page 314
11.4.3.7 Spatial Parameters โ Uses in AM......Page 316
11.4.4 Topography Segmentation and Characterisation of Surface Features......Page 317
11.4.5 Topography Segmentation and Characterisation of Surface Features โ Uses in AM......Page 318
11.5 Uncertainty in Surface Topography Measurement and Characterisation......Page 320
11.6 Current Research and Future Look......Page 321
References......Page 322
12.1 Introduction......Page 328
12.2.1 Evolution of X-Ray Computed Tomography......Page 329
12.2.2 Industrial CT Systems โ Configurations and Components......Page 330
12.2.2.2 X-Ray Detector......Page 332
12.2.3 CT Scanning Process......Page 333
12.3.1 Main Error Sources and CT Image Artefacts......Page 337
12.3.2 Metrological Performance Verification......Page 340
12.3.4 Reference Objects......Page 341
12.4 Applications of CT Metrology for AM......Page 342
12.4.1 Dimensional and Geometrical Product Verification......Page 345
12.4.2 Internal Defect Analysis......Page 347
12.4.3 Surface Topography Characterisation......Page 350
12.4.4 Powder Feedstock Characterisation......Page 351
12.4.5.1 CT for Product Development......Page 353
12.4.5.2 CT for Process Optimisation......Page 354
References......Page 355
Chapter 13 On-Machine Measurement, Monitoring and Control......Page 362
13.1 Introduction......Page 363
13.2 Basic Definitions and Terminology......Page 364
13.3.1.2 Equipment-Induced Defects......Page 365
13.3.1.4 Process SettingโInduced Defects......Page 366
13.3.2.1 Porosity......Page 367
13.3.2.2 Residual Stresses, Cracks and Delamination......Page 368
13.3.2.4 Balling......Page 369
13.3.2.5 Dimensional and Geometrical Deviations......Page 370
13.3.2.6 Surface Defects......Page 371
13.4.1 Basic Principles......Page 372
13.4.1.1 Electromagnetic Spectral Ranges for On-Machine Measurements......Page 373
13.4.1.2 Spatially Integrated Sensors......Page 376
13.4.1.3 Spatially Resolved Sensors......Page 377
13.4.2 Data Gathering Levels......Page 378
13.4.3.1 Co-Axial Sensing......Page 380
13.4.3.2 Off-Axis Sensing......Page 382
13.4.4 Mapping between On-Machine Sensing, Process Signatures and Process Defects......Page 385
13.5.1 On-Machine Topography Reconstruction......Page 387
13.5.2 Other Methods......Page 388
13.6.1.1 False Alarms and False Negatives: Type I and Type II Errors......Page 389
13.6.1.2 Control Charts......Page 390
13.6.2.2 On-Machine Monitoring Example, Level 2......Page 391
13.7 Process Control......Page 392
13.7.1 Feedback Control......Page 393
13.8 Current Research and Future Look......Page 395
References......Page 400
Index......Page 408