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Metallic Powders for Additive Manufacturing. Science and Applications. Edition No. 1

  • Book

  • 608 Pages
  • March 2024
  • John Wiley and Sons Ltd
  • ID: 5910782
Metallic Powders for Additive Manufacturing

Overview of successful pathways for producing metal powders for additive manufacturing of high-performance metallic parts and components with tailored properties

Metallic Powders for Additive Manufacturing introduces the readers to the science and technology of atomized metal powders beyond empirical knowledge and the fundamental relationships among the chemistry, microstructure, and morphology of atomized metallic powders and their behavior during additive manufacturing.

The text sets a foundation of the underlying science that controls the formation and microstructure of atomized metallic droplets, including the relations among the properties of metallic powders, their performance during the manufacturing processes, and the resulting products.

Other topics covered include the influence of powder on defect formation, residual stress, mechanical behavior, and physical properties. The concluding two chapters encompass considerations of broader societal implications and overarching themes, including the exploration of alternative feedstock materials, economic analysis, and sustainability assessment. These chapters offer valuable perspectives on the prospective trajectory of the field.

Written by a team of experienced and highly qualified professors and academics, Metallic Powders for Additive Manufacturing includes information on: - Atomization techniques such as Vacuum Induction Gas Atomization (VIGA), Electrode Induction Melting Gas Atomization (EIMGA), and Plasma Rotating Electrode Process (PREP) - Atomization science and technology, covering control of atomization parameters, powder size distribution, effect of processing variables, and theoretical models of atomization - Heat transfer and solidification of droplets, covering nucleation, microstructure development, and important thermal and solidification conditions during atomization - Atomization of Al, Fe, Ni, Co, Ti, and high entropy alloys, as well as composite powders for additive manufacturing, and guidelines for atomization equipment and powder handling - Fundamental processing principles in a variety of metal additive manufacturing processes - Powder characteristics and requirements for different additive manufacturing processes - Effect of powder chemistry and physical characteristics on additive manufacturing processes, and the microstructure and properties of the built parts - Evaluation of alternative feedstock sources for metal additive manufacturing, beyond gas atomized powder - Economic and sustainability perspectives on powder production and additive manufacturing

Metallic Powders for Additive Manufacturing is an excellent combination of rigorous fundamentals and a practice-oriented and forward-looking resource on the subject for materials scientists and practicing engineers seeking to understand, optimize, and further develop the field of powder production and additive manufacturing.

Table of Contents

About the Authors xv

Preface xix

Acknowlegments xxiii

Part I Atomization of Metallic Powder 1

1 Overview of Atomization Techniques 3

1.1 History of Metallic Powder and Atomization Techniques 3

1.1.1 Metal Powders 3

1.1.2 Atomizer Designs 4

1.2 Melt Atomization 8

1.3 Gas Atomization (GA) 9

1.4 Vacuum Induction Gas Atomization (VIGA) 11

1.5 Electrode Induction Melting Gas Atomization (EIMGA) 12

1.6 Plasma Rotating Electrode Process (PREP) 15

1.7 Spark Plasma Discharge Spheroidization (SPDS) 16

1.8 Plasma Induction Gas Atomization (PIGA) 18

1.9 Plasma-Atomized Wire (PAW) 19

1.10 Water Atomization (WA) 20

1.11 Summary 22

Nomenclature 23

References 23

2 Atomization 25

2.1 Introduction 25

2.2 Atomization Technology 26

2.2.1 Energy Consumption During Atomization 26

2.2.2 Molten Metal Atomization Methods 27

2.2.3 Subsonic Gas Atomization 28

2.2.4 Supersonic Gas Atomization 30

2.2.5 Ultrasonic Gas Atomization (USGA) 31

2.2.6 Centrifugal Atomization 34

2.2.7 Mono-sized Droplet Atomization 36

2.3 Formation of Droplets 38

2.3.1 Regimes of Liquid Breakup 38

2.3.2 Mechanisms of Atomization 38

2.3.3 Atomization of Cylindrical Liquids 43

2.3.4 Atomization of Liquid Sheets 45

2.3.5 Droplet Formation Under Conventional Gas Atomization Conditions 47

2.3.6 Droplet Formation During Centrifugal Atomization 49

2.4 Control of Atomization Parameters 50

2.4.1 Classification of Processing Variables 50

2.4.2 Factors Affecting Metal Flow Rate 50

2.4.3 Metal Flow Rate 55

2.4.4 Gas Flow Rate and Velocity 57

2.5 Powder Size Distribution 61

2.5.1 Powder Size 62

2.5.2 Size Distribution 63

2.6 Effect of Processing Variables 64

2.6.1 Important Atomization Variables 64

2.6.2 Atomization Pressure 64

2.6.3 Liquid Flow Rate 66

2.6.4 Gas Velocity 67

2.6.5 Gas Flow Rate 69

2.6.6 Mechanical Disturbances 70

2.6.7 Physical Properties of Atomization Gas 71

2.6.8 Liquid Viscosity 71

2.6.9 Liquid Surface Tension 73

2.6.10 Fluid Temperature 74

2.6.11 Solidification Event 76

2.6.12 Apex Angle 78

2.6.13 Variables in Centrifugal Atomization 78

2.7 Theoretical Models of Atomization 80

2.7.1 Breakup of Liquid Rods or Fragments 80

2.7.2 Formation of Droplets by Sheet Breakup 82

2.8 Empirical Models 86

2.8.1 Nukiyama and Tanasawa Analysis 87

2.8.2 Wigg Analysis 87

2.8.3 Kim and Marshall Analysis 90

2.8.4 Schmitt Analysis 91

2.8.5 Weiss and Worsham Analysis 91

2.8.6 Lubanska Analysis 92

2.9 Summary 94

Nomenclature 94

References 96

3 Heat Transfer and Solidification of Droplets 101

3.1 Introduction 101

3.2 Important Thermal and Solidification Conditions 103

3.2.1 Thermal Conditions 103

3.2.2 Solidification Considerations 105

3.3 Heat Transfer 107

3.3.1 Heat Transfer Mechanisms 107

3.3.2 Heat Transfer Coefficient 109

3.3.3 Gas Velocity 111

3.3.4 Droplet Velocity 112

3.4 Nucleation 116

3.4.1 Homogeneous Nucleation 117

3.4.1.1 Free Energy of Nucleation 117

3.4.1.2 Nucleation Rate 120

3.4.1.3 Homogeneous Undercooling 121

3.4.2 Heterogeneous Nucleation 125

3.4.2.1 Heterogeneous Nucleants 126

3.4.2.2 Heterogeneous Nucleation Undercooling 128

3.4.2.3 Distribution of Nucleants 130

3.5 Solidification of Droplets 134

3.5.1 Temperature Distribution in Droplets 135

3.5.2 Newtonian Solidification 136

3.5.3 Cooling Rate 137

3.5.4 Solidification Time 140

3.5.5 Interfacial Velocity 141

3.5.5.1 Equilibrium Solidification 141

3.5.5.2 Dynamic Solidification 143

3.5.5.3 Stepwise Growth 145

3.5.5.4 Experimentally Determined Interfacial Velocities 147

3.6 Microstructural Development 151

3.6.1 Solidification Morphology 151

3.6.2 Microstrutural Refinement 155

3.6.2.1 Dendrite Arm Spacing 155

3.6.2.2 Grain Size 159

3.6.3 Phase Selection 162

3.6.4 Solute Redistribution 166

3.7 Summary 169

Nomenclature 170

References 172

4 Composite Powders for Additive Manufacturing 179

4.1 Introduction 179

4.2 Fabrication Methods 180

4.2.1 Atomization and Co-injection 180

4.2.2 Atomization of Premixed MMCs 186

4.2.3 Reactive Atomization 186

4.2.3.1 Gas-Liquid Interactions 186

4.2.3.2 Liquid-Liquid Interactions 192

4.2.3.3 Liquid-Solid Interactions 192

4.3 Incorporation of Reinforcements During Co-injection 193

4.3.1 Incorporation Behavior of Reinforcements 193

4.3.2 Penetration of Semiliquid Droplets 197

4.3.2.1 Energy Balance 198

4.3.2.2 Force Balance 200

4.3.2.3 Combined Energy and Force Balance 201

4.3.2.4 Penetration Depth 204

4.3.2.5 Particle Type, Morphology, and Solid Fraction 204

4.3.3 Penetration of Solid Droplets 206

4.4 Particle Behavior During Solidification 207

4.4.1 Engulfment of Reinforcements by Solid-Liquid Interface 207

4.4.1.1 Mass Balance 209

4.4.1.2 Force Balance 209

4.4.1.3 Thermal Field 210

4.4.1.4 Thermal Field and Force Balance 211

4.4.1.5 Engulfment During Droplet Solidification 211

4.4.2 Mechanical Entrapment of Reinforcements by Solidification Fronts 213

4.4.3 Reinforcement-Induced Nucleation 214

4.4.3.1 Free Energy Effects 214

4.4.3.2 Thermal Effects 215

4.5 Other Methods for Fabricating MMC Powders 219

4.5.1 Mechanical Milling and Cryomilling 220

4.5.2 Surface Coating 224

4.5.3 Reaction Synthesis 226

4.6 Summary 227

Nomenclature 228

References 230

5 Diagnostic and Characterization Techniques 235

5.1 Introduction 235

5.2 Flow Visualization Techniques 235

5.3 Particle Image Velocimetry (PIV) 239

5.4 Particle Counting, Sizing, and Velocity Probe (PCSV-P) 243

5.5 High-Speed Cinematography/Video 246

5.6 High-Speed Off-Axis Holographic Cinematography 249

5.7 Infrared Thermal Imaging 252

5.8 Phase Doppler Particle Analysis (PDPA) 253

5.9 Surface Ionization For Monitoring Particles (SIMP) 255

5.10 Intelligent Sensors 255

5.11 Summary 259

References 260

6 Atomization Improvements for Additive Manufacturing 263

6.1 Introduction 263

6.2 Gas and Metal Flow Rates 263

6.3 Gas Velocity 264

6.4 Physical Characteristics of the Gas and Melt 265

6.5 Powder Size Distribution and Other Variables 266

6.6 Powder Morphology 268

6.7 Powder Satellites 272

6.8 Powder Porosity 275

6.9 Summary 278

Nomenclature 278

References 279

7 Atomization of Alloys 283

7.1 Introduction 283

7.2 Aluminum-Based Alloys and Powders 283

7.2.1 Al-Based Alloy Powders 284

7.2.2 Al-Si Alloys 285

7.2.3 Al-Cu Alloys 288

7.2.4 Al-Transition Metal Alloys 289

7.2.5 Al-Li Alloys 289

7.2.6 Al-Zn-Mg-Cu Alloys 292

7.3 Iron-Based Alloys and Powders 296

7.3.1 Fe-Based Alloy Powders 297

7.3.2 Stainless Steels 300

7.3.3 Tool Steels 301

7.3.4 Other Iron-Based Materials 303

7.4 Nickel-Based Alloys and Powders 303

7.4.1 Ni-Based Alloy Powders 304

7.4.2 Inconel Alloys 306

7.4.3 René Alloys 308

7.4.4 Other Superalloys 310

7.5 Titanium-Based Alloy and Powders 311

7.5.1 Ti-Based Alloys 311

7.5.2 Ti-Based Alloy Powders 313

7.6 Cobalt-Based Alloys and Powder 319

7.6.1 Co-Based Alloys 319

7.6.2 Co-Based Alloy Powders 321

7.7 High-Entropy Alloys and Powders 323

7.7.1 High-Entropy Alloys 323

7.7.2 High-Entropy Alloy Powders 325

7.8 Summary 329

Nomenclature 329

References 331

Part II Powders in Additive Manufacturing 341

8 Overview of Metal Additive Manufacturing Technologies 343

8.1 History of Metal Additive Manufacturing Techniques 343

8.2 Powder Bed Fusion (PBF) 345

8.2.1 PBF Processing Principles 345

8.2.2 Feedstock Powder for PBF 347

8.2.3 Post-processing After PBF 348

8.3 Directed Energy Deposition (DED) 348

8.3.1 DED Processing Principles 348

8.3.2 Feedstock Powder for DED 349

8.3.3 Post-processing After DED 351

8.4 Metal Binder Jetting 351

8.4.1 BJT Processing Principles 351

8.4.2 Feedstock Powder for BJT 352

8.4.3 Post-processing After BJT 352

8.5 Sheet Lamination (SHL) 353

8.6 Summary 354

Acronym/Nomenclature 354

References 355

9 Powder-Laser-Melt Pool Interactions 361

9.1 Introduction 361

9.2 Laser and Laser-Material Interactions 362

9.2.1 Laser-Matter Interactions 362

9.2.2 Laser-Material Processing 363

9.3 Laser-Material Interactions During DED Processing 364

9.3.1 Inflight Particle Heating 364

9.3.2 Thermal Behavior of Melt Pool 366

9.3.3 Interactions Between Particles and Melt Pool 367

9.4 Laser-Material Interactions During PBF Processing 372

9.4.1 Powder Layer Characteristics and Spreading 373

9.4.2 Laser Beam-Powder Interactions 375

9.4.3 Spatter and Denudation Formation 378

9.4.4 Powder Degradation 381

9.5 Summary 383

Nomenclature 383

References 384

10 Influence of Powder Chemistry on Additive Manufacturing 387

10.1 Introduction 387

10.2 Alloy Compositions 387

10.3 Impurities and Segregation 391

10.4 High Entropy Alloys (Multi-Principal Element Alloys) 392

10.5 Metal Matrix Composites 394

10.6 In-Situ Alloying (In-Process Alloying) 396

10.7 Summary 397

Nomenclature 397

References 397

11 Physical Powder Characteristics and Additive Manufacturing 403

11.1 Introduction 403

11.2 Characterization of Physical Powder Properties 403

11.2.1 Powder Sampling 403

11.2.2 Particle Size and Particle Size Distribution 405

11.2.3 Particle Morphology 407

11.2.4 Powder Flow Characteristics 409

11.3 Powder Production Methods 412

11.3.1 Gas Atomization 413

11.3.2 Water Atomization 413

11.3.3 Mechanical Milling 414

11.4 Powder Reuse, Recycling, and Recovery 414

11.5 Influence of Powder Production Methods and Parameters On Powder Properties and Additive Manufacturing 416

11.6 Influence of Powder Reuse, Recycling, and Recovery on Powder Characteristics and Additive Manufacturing 420

11.7 Postproduction Methods for Treating Powders 423

11.8 Summary 425

Nomenclature 426

References 427

12 Microstructure Evolution and Powder Effects 433

12.1 Introduction 433

12.2 Grain Structure and Phase Composition 433

12.2.1 Columnar-to-Equiaxed Transition (CET) 433

12.2.2 Phase Composition 439

12.3 Solidification Kinetics 441

12.4 Solid-State AM 445

12.5 Summary 448

Nomenclature 448

References 450

13 Defect Formation and Powder Effects 455

13.1 Introduction 455

13.2 Porosity 455

13.3 Cracking and Delamination 460

13.4 Interfacial Structure and Grain Size 462

13.5 Segregation 470

13.6 Surface Roughness 472

13.7 Summary 475

Nomenclature 475

References 476

14 Residual Stress and Powder Effects 479

14.1 Introduction 479

14.2 Measuring Residual Stress 479

14.3 Powder Characteristics 481

14.4 Pre-processing Heat Treatment 482

14.5 Process Parameters 483

14.6 Post-processing Treatments 487

14.7 Summary 490

Nomenclature 490

References 491

15 Physical and Chemical Behavior and Powder Effects 493

15.1 Introduction 493

15.2 Density 493

15.3 Surface Appearance 494

15.4 Elastic and Plastic Deformation 496

15.5 Hardness 497

15.6 Fracture and Fatigue 498

15.7 Corrosion and Wear 502

15.8 Oxidation 509

15.9 Summary 510

Nomenclature 511

References 511

16 Economic and Sustainability Assessments of Powder Production and Additive Manufacturing 513

16.1 Introduction 513

16.2 Resource Utilization 513

16.2.1 Materials Utilization 514

16.2.2 Energy Utilization 516

16.2.3 Other Resources 518

16.3 Economic Assessment 519

16.3.1 Cost Breakdown and Models 520

16.3.2 Supply Chain Effects 524

16.4 Sustainability Assessments 527

16.4.1 Hazard Traits of Metals and Occupational Exposure Potential 528

16.4.2 Life Cycle Assessment of Environmental Impact 542

16.5 Summary 546

Nomenclature 547

References 549

17 Future Directions and Challenges 555

17.1 Introduction 555

17.2 Future Directions in the Atomization of Powders 556

17.2.1 Technology Improvements 556

17.2.2 Custom Alloys and Composites 557

17.2.3 Additive Manufacturing 557

17.3 Future Directions and Challenges in the Additive Manufacturing of Metal Alloys 558

17.3.1 Machine Learning and Artificial Intelligence 558

17.3.2 Novel Structures 560

17.3.3 Hybrid Manufacturing 560

17.3.4 Diagnostic Methods 561

17.3.5 Future Challenges 561

17.4 Summary 561

References 562

Index 565

Authors

Enrique J. Lavernia Texas A&M University, College Station, TX. Kaka Ma Colorado State University, Fort Collins, CO. Julie M. Schoenung Texas A&M University, College Station, TX. James F. Shackelford University of California, Davis, CA. Baolong Zheng University of California, Irvine, CA.