The rapid technological developments during the later half of the 20th century have demanded materials that are stronger, capable of use at much higher temperatures, more corrosion-resistant, and much less expensive than those currently used. These demands become even more significant on the threshold of the new century and the millennium. Significant improvements in properties can only be achieved by processing the materials under far-from-equilibrium (or non-equilibrium) conditions. Several new processing technologies have been developed during the past few decades including, rapid solidification, spray forming, mechanical alloying, ion mixing, vapor deposition, laser processing and plasma processing.
Remarkable advances have been made in recent years in the science and technology of these processes used to synthesize, characterize, and apply these materials processed under non-equilibrium conditions. Some of these techniques have evolved from laboratory curiosity to commercial-scale manufacturing in just a few years. In other cases, industrial necessity prompted development of the technology, and the science followed later.
The chapters in this book have been written by people who are world-recognized experts in their respective fields. Each chapter describes the principles, processing techniques, special features of the materials produced, and their applications. An extensive list of references is provided at the end of each chapter that will facilitate location of additional information on specific aspects of any technique.
Series Preface xv Preface xvii List of Contributors xix Introduction 1(4) R. W. Cahn Thermodynamics and Kinetics of Metastable Phase Formation 5(18) K. N. Ishihara Introduction 5(1) Thermodynamics of Metastable Phase Formation 5(7) Free Energy of Elements 5(2) Free Energy of Alloy Phases 7(2) Determination of Free Energy of Metastable Phases 9(2) Lattice Parameter of the Supersaturated Phase 11(1) Kinetics of Metastable Phase Formation 12(7) Nucleation of Metastable Phases 13(2) Nucleation of Alloy Phases 15(3) Crystal Growth Rate of Metastable Phases 18(1) Summary 19(1) List of Symbols 19(4) References 20(3) Rapid Solidification 23(26) H. Jones Introduction 23(1) Methods of Rapid Solidification 24(4) Droplet Methods 24(2) Spinning Methods 26(1) Surface-Melting Methods 27(1) Constitution and Microstructure Formation by Rapid Solidification 28(6) Non-Equilibrium Constitution 29(3) Microstructure Formation 32(2) Properties, Performance and Applications of Rapidly Solidified Materials 34(15) Properties and Performance 34(7) Applications of Rapid Solidification 41(2) References 43(2) Selected Bibliography 45(4) Mechanical Alloying 49(40) C. Suryanarayana Introduction 49(1) Nomenclature 50(1) The Process of Mechanical Alloying 51(4) Raw Materials 51(1) Process Control Agents 52(1) Type of Mills 52(1) SPEX Shaker Mills 53(1) The Planetary Ball-Mill 53(1) Attritor Mills 53(1) Commercial Mills 53(1) New Designs 54(1) Mechanism of Alloying 55(1) Consolidation 56(2) Synthesis of Non-Equilibrium Phases 58(16) Solid Solubility Extensions 59(3) Synthesis of Intermetallics 62(2) Disordering of Ordered Intermetallics 64(2) Nanocrystalline Materials 66(1) Solid-State Amorphization 67(4) Displacement Reactions 71(3) Power Contamination 74(1) Modeling 75(1) Industrial Applications 76(4) Nickel-Base Alloys 77(2) Iron-Base Alloys 79(1) Aluminum-Base Alloys 79(1) Magnesium-Base Alloys 80(1) Concluding Remarks 80(9) References 81(8) Laser Processing 89(32) K. F. Kobayashi Principles of Lasers 89(1) Classifications of Laser Processing 89(3) Analysis of the Laser Melting and Quenching Process 92(6) Heat Transfer 92(1) Absorption Phenomena of Laser 92(1) Pulsed Laser 93(1) Continuous Wave (CW) Laser 94(2) Kinetic Conditions for Solidification 96(1) Kinetic Conditions for Amorphous Phase Formation 96(1) Solidification Modes in the Laser Processing of Materials 97(1) Microstructure Selection Maps (MSM) for Alloys 97(1) Laser-Quenching 98(2) Amorphous Phase Formation 98(1) Formation of Crystalline Phases 99(1) Laser Surface-Alloying and Cladding 100(2) Ferrous Alloys 100(1) Non-Ferrous Alloys 101(1) Laser-Annealing 102(4) Laser-Beam Joining 106(9) Welding of Structural Materials 106(1) Ferrous-Based Alloys 106(2) Non-Ferrous Alloys 108(4) Microjoining 112(3) Conclusions 115(6) References 115(6) Thermal Plasma Processing 121(32) P. V. Ananthapadmanabhan N. Venkatramani Introduction 121(2) Advantages of Plasma Processing 121(2) Thermal Plasmas 123(6) Principles of Plasma Generation 123(1) DC Plasma Torches 124(2) AC Plasma Torches 126(1) RF Plasma Torches 126(1) Plasmagen Gases 127(1) Plasma-Particle Interaction 128(1) Plasma Processing Systems 129(1) Processing of Materials 129(18) Plasma-Spraying 129(2) Structure of Sprayed Deposits 131(1) Plasma Spray-Deposited Materials 132(2) Low-Pressure Plasma-Spraying 134(1) Reactive Plasma-Spray Forming 135(1) Plasma Spheroidization 135(2) Plasma Reactors of Furnaces 137(1) Plasma Decomposition 137(1) Plasma Metallurgy 138(2) Processing of Ceramics 140(1) Treatment of Hazardous Wastes 141(1) Processing of Metastable Phases 141(1) Plasma Deposition of Diamonds 141(1) Thermal Plasma Synthesis of Ultrafine Alumina Powder 142(5) Summary and Conclusions 147(6) Acknowledgments 148(1) References 148(5) Spray-Forming 153(44) Bing Li E. J. Lavernia Introduction 153(1) Principles 154(3) Variations and Distinctions 157(11) Variations 157(1) Crucible: Introduction Skull Melting/Spray-Forming 158(1) Atomizer: Circular vs. Linear Spray-Forming 158(1) Atomizer: Close-Coupled vs. Free-Fall Spray-Forming 159(1) Atomization Gas: Reactive Spray-Forming 160(3) Substrate: Near Net Shape Spray-Forming 163(1) Spray-Forming and Co-Injection 163(3) Nomenclature 166(1) Spray-Atomization 166(1) Related Processing Techniques 167(1) Applicability 168(4) Non-Equilibrium Phenomena in Spray-Forming 172(17) Non-equilibrium Nature 173(1) Rapid Solidification in Atomized Droplets 173(3) Transient Semi-Solid Layer in Deposition Stage 176(2) Non-Equilibrium Related Features in the Deposit 178(1) Metastable Phases 178(1) Extended Solid Solubility 178(1) Absence of Macrosegregation/Minimized Microsegregation 179(1) Refinement 180(1) Effects of Non-equilibrium Features on Mechanical/Physical Properties 181(2) Direct Effects 183(2) Indirect Effects 185(4) Concluding Remarks 189(8) Acknowledgments 189(1) References 189(8) Ion-Mixing 197(28) B. X. Liu Introduction 197(2) Brief Description of Underlying Physics in Ion Mixing 199(1) Thermodynamics of Alloy Phase Formation 200(3) Miedemas Theory and Alonsos Method 200(1) Interfacial Free Energy in the Multilayers 201(2) Experimentation of Ion-Mixing 203(2) Sample Design 203(2) Ion-Mixing Parameters 205(1) Characterization Methods 205(1) Amorphous Phase Formation 205(8) Glass-Forming Ability of Systems with a Negative Heat of Formation 206(1) Glass-Forming Ability of Systems with a Positive Heat of Formation 207(1) Amorphous Alloys Formed Within Restricted Compositions 207(1) Amorphous Alloys Formed in a Broad Composition Range 207(4) Nominal and Intrinsic Glass-Forming Ability 211(2) Formation of Metastable Crystalline Alloys 213(5) Structural Classification of the Metastable Crystalline Phases 213(1) Solid Solutions 213(1) h.c.p.-I and f.c.c.-I Phases 213(2) h.c.p.-II and f.c.c.-II Phases Based on b.c.c. Metals 215(1) Free Energy Calculation of the MX Phases 216(2) Interface-Generated Solid-State Vitrification in Systems with a Positive Heat of Formation 218(1) Concluding Remarks 219(6) Acknowledgments 220(1) References 220(5) Physical Vapor Deposition 225(32) J. S. Colligon Introduction 225(1) Development of PVD 225(3) Deposition Methods 228(10) Evaporation 228(1) Molecular Beam Epitaxy (MBE) 229(1) Sputtering 229(2) Ion-Assisted Deposition 231(4) Magnetron Sputtering 235(3) Influence of Energy on Coatings 238(5) Film Morphology and Density 238(1) Nucleation and Adhesion 239(1) Metastable Phases 240(1) Microstructure 240(3) Applications of PVD Coatings 243(5) Optical Coatings 243(2) Corrosion Protective Coatings 245(1) Hard Coatings 246(2) Future Trends 248(9) Acknowledgment 249(1) References 249(8) Chemical Vapor Deposition 257(32) F. Teyssandier A. Dollet Introduction 257(2) Presentation 258(1) Gas-Phase Transport and Reactivity 259(8) Non-Reactive Fluid Flow 260(1) Geometrical Effects 260(1) Influence of Operating Conditions 261(1) Reactive Flows 261(2) Thermodynamic Approach 263(1) Gas-Phase Mechanisms and Kinetics 264(1) Simulations of the Gas-Phase Composition 264(1) Nucleation and Growth of Solid Particles from the Gas Phase 265(2) Solid Phase Formation 267(14) Solid-Gas Thermodynamic Equilibrium Approach 267(1) The Structure of CVD Layers 268(2) The Driving Force for Crystal Growth from the Vapor Phase 270(1) Surface Mechanisms and Kinetics 271(1) Rate of Elementary Surface Processes 271(1) Estimation of the Kinetics of Surface Processes in CVD 272(1) Heterogeneous Nucleation 273(1) Nucleation Theories 274(1) Two- and Three-Dimensional Nucleation 275(1) Epitaxial Nucleation and Growth 275(1) Multi-Component Nucleation and Chemical Reactions 276(1) Nucleation Enhancement 276(1) Selective Vapor Deposition 277(1) Theoretical and Experimental Studies of Nucleation in CVD 277(1) Crystal Growth 278(1) Mechanisms of Crystal Growth 278(1) Classification of Crystal Faces 278(1) Crystalline Morphology 279(1) Morphology and Normal Growth Rate of Crystal Faces 279(2) Relation between Preferred Orientation and Morphology of Polycrystalline Films 281(1) Theoretical Studies of Crystal Growth from the Vapor Phase 281(1) Conclusions 281(8) References 282(7) Compustions Synthesis 289(24) S. B. Bhaduri S. Bhaduri Introduction 289(2) Thermodynamic Considerations 291(3) Kinetic Considerations 294(1) Field-Activated Combustion Synthesis 295(2) The ``Azide Process 297(2) SHS Reactions in Synthesizing Ti3SiC2 299(2) Controlled Reactions in the Ti-Binary System 301(3) Auto-Ignition Synthesis of Nanocrystalline Oxides 304(3) Non-Equilibrium Effects 307(1) Concluding Remarks 307(6) Acknowledgments 308(1) References 308(5) Nanostructured Materials 313(34) C. Suryanarayana C. C. Koch Introduction 313(1) Classification 313(1) Preparation 314(5) Inert Gas Condensation 314(2) Rapid Solidification 316(1) Electrodeposition 317(1) Chemical Reactions 318(1) Mechanical Attrition 318(1) Devitrification 319(1) Structure 319(4) Microstructure 320(1) Atomic Structure of the Crystal Lattice 321(1) Atomic Structure of the Grain Boundaries 321(1) Triple Junctions and Higher-Order Grain Junctions 322(1) Stability 323(3) Grain Growth in Nanocrystalline Materials 323(1) Grain Growth at Ambient Temperature 324(1) Examples of Grain Growth Inhibition 324(1) Isothermal Grain Growth Kinetics 325(1) Particulate Consolidation 326(1) Properties 327(10) Diffusion and Sinterability 327(1) Mechanical Properties 328(1) Elastic Properties 328(1) Hardness and Strength 329(1) Ductility and Toughness 329(2) Superplastic Behavior 331(1) Deformation Mechanisms in Nanoscale Materials 331(2) Magnetic Properties 333(1) Fundamental Properties 333(1) Soft Magnetic Materials 333(1) Hard Magnetic Materials 333(2) Other Ferromagnetic Nanocrystalline Materials 335(1) Chemical Properties 335(1) Corrosion Behavior 335(1) Catalytic Properties 335(2) Applications---Present and Potential 337(4) Structural Applications 337(1) Cutting Tools 337(1) Nanocomposites 338(1) Superplastic Materials 339(1) Coatings 339(1) Magnetic Applications 340(1) Catalysts and Hydrogen Storage Materials 340(1) Functional Nanostructures---Electronic Applications 341(1) Concluding Remarks 341(6) References 342(5) Powder Consolidation 347(28) J. R. Groza Introduction 347(1) Metastability in Powder Consolidation 348(1) Consolidation of Metastable Powders 349(7) Sintering Mechanisms 352(1) Scaling Laws 353(2) Powder Contamination 355(1) Consolidation Methods 356(12) Conventional Sintering 356(1) Cold Compaction 356(2) Warm Compaction 358(1) Conventional Sintering of Nanopowders 359(2) Nano-Composite Densification 361(1) Grain-Size Control 361(2) Pressure Consolidation of Metastable Powders 363(1) Pressure-Assisted Consolidation Methods 364(2) Non-Conventional Sintering Methods 366(1) Microwave Sintering 366(1) Field-Assisted Sintering 366(2) Shockwave Consolidation 368(1) Concluding Remarks 368(7) Acknowledgments 369(1) References 369(6) Bulk Amorphous Alloys 375(42) A. Inoue History of Bulk Amorphous Alloys 375(1) Dominant Factors for High Glass-Forming Ability 376(4) Continuous Cooling Transformation of Alloys with High Glass-Forming Ability 380(3) Preparation Methods and Elemental Effect 383(4) Structural Relaxation and Glass Transition 387(5) Physical Properties 392(3) Density 392(1) Electrical Resistivity 393(1) Thermal Expansion Coefficient 394(1) Mechanical Properties 395(4) Viscoelasticity 399(4) Soft Magnetic Properties 403(3) Formation and Soft Magnetic Properties of Bulk Amorphous Alloys 403(3) Viscous Flow and Micro-Formability of Supercooled Liquid 406(7) Feature of Phase Transition of Bulk Amorphous Alloys 409(1) Deformation Behavior of Supercooled Liquid 409(3) Micro-Forming of Supercooled Liquid 412(1) Applications and Future Prospects 413(4) References 413(4) Author Index 417(2) Subject Index 419
Professor C. Suryanarayana received his B.Sc. degrees in Science from Andhra University, Waltair, the B.E. degree in Metallurgy from the Indian Institute of Science in Bangalore, and the M.S. and Ph.D. degrees in Physical Metallurgy from the Banaras Hindu University in Varansai, India. He was a faculty member at the Banaras Hindu University for 23 years and was a Senior Scientist/Visiting Professor at Oxford University (UK), Atomic Energy Establishment, Mol (Belgium), Tohoku University, Sendai (Japan), Wright-Patterson Air Force Base in Dayton, OH, Washington State University in Pullman, WA, and Chungnam National University in Taejon (Korea). Before joining his present position at the Colorado School of Mines, he was a Professor of Metallurgy and Associate Director of the Institute for Materials and Advanced Processes, University of Idaho, Moscow, ID. Professor Suryanarayana has published more than 250 technical papers in the areas of rapid solidification, mechanical alloying, innovative synthesis/processing techniques, metallic glasses, quaiscrystals, and nanostructures and has authored/edited 10 technical books. The most recent one was an undergraduate textbook on "X-Ray Diffraction: A Practical Approach" being published by Plenum Publishing Corporation. The major emphasis of his research investigations has been on synthesis-structure-property relationships. He extensively makes use of transmission electron microscopy and x-ray diffraction techniques for materials characterization. Professor Suryanarayana received numerous awards including the National Metallurgist's Day award of the Government of India, the Pandya Silver Medal of the Indian Institute of Metals, and the Young Scientist's Medal of the Indian National Science Academy. He is a Fellow of the ASM International, Fellow of the Institute of Materials, London (UK), a member of TMS, a Life Member of the Materials Research Society of India, a Life Member of the Electron Microscope Society of India, and
