Elements of Rapid Solidification

1 Introduction and Background.- 1.1 Background.- 1.2 Liquid-to-Crystal Transition: Undercooling and Nucleation.- 1.2.1 Thermodynamics and Kinetics of Solidification.- 1.2.2 Undercooling.- 1.2.3 Phase Diagram for Metastable States.- 1.3 Metallic Glasses.- 1.3.1 Glass Formation by Rapid Quenching.- 1.3.2 Glass-Forming Composition.- 1.3.3 Crystallization and Structural Relaxation.- 1.3.4 Atomic Structure of Metallic Glasses.- 1.4 Metastable Crystalline Phases.- 1.4.1 Non-Equilibrium in Crystalline Phases.- 1.4.2 Two Examples of Solubility Extension. The Ag-Cu and Ti-Cu Systems.- 1.4.3 Metastable Crystalline Phases Not Present in Equilibrium — Examples.- References.- 2 Synthesis and Processing.- 2.1 Heat Transfer and Solidification Kinetics.- 2.2 Droplet Methods.- 2.3 Spinning Methods.- 2.4 Surface Melting Technologies.- 2.5 Consolidation Technologies.- References.- 3 Structure and Characterization of Rapidly Solidified Alloys.- 3.1 Characterization Techniques.- 3.1.1 Structural Characterization.- 3.1.2 X-Ray Radial Distribution Function.- 3.1.3 High-Resolution Electron Microscopy.- 3.1.4 Differential Scanning Calorimetry — Phase Transformation and Separation.- 3.1.5 Electrical Resistivity.- 3.1.6 Microhardness Measurements.- 3.1.7 Mössbauer Spectroscopy.- 3.2 Total Scattering Intensity from Amorphous and Nanocrystalline Alloys.- 3.2.1 Atomic Distribution Functions.- 3.2.2 Scattered Intensity.- 3.2.3 Reduced Atomic Distribution Functions.- 3.2.4 Coordination Numbers in Binary Amorphous Alloys.- 3.2.5 Topological and Chemical Order in Binary Solutions.- 3.3 Diffraction Theory of Powder Pattern Peaks from Nanocrystalline Materials.- 3.3.1 Fourier Analysis of the Peak Profiles.- 3.3.2 Integral Breadth of Powder Pattern Peaks.- 3.4 Experimental Diffraction Techniques.- 3.4.1 Radiation Sources.- 3.4.2 Diffraction Methods.- 3.4.3 Variable? Method 72.- 3.4.4 Variable ? Method.- 3.4.5 Analysis of the Diffraction Pattern.- a) Total Diffracted Intensity from Amorphous and Nanocrystalline Samples.- b) Fourier Analysis of the Profiles of Powder Pattern Peaks.- 3.5 Structure of Amorphous and Nanocrystalline Alloys.- 3.5.1 Amorphous Beryllium Alloys.- 3.5.2 Amorphous and Nanocrystalline Vanadium Alloys.- 3.5.3 Amorphous and Nanocrystalline Tungsten Alloys.- 3.6 Selected Examples of Electron-Microscopy Analysis.- References.- 4 Atomic Transport and Relaxation in Rapidly Solidified Alloys.- 4.1 Basic Equations of Diffusion.- 4.2 Self-Diffusion in Amorphous Alloys.- 4.2.1 Radiotracer Technique.- 4.2.2 Non-Equilibrium and Quasi-Equilibrium of Diffusional Properties.- 4.2.3 Review of Diffusion Data.- 4.2.4 Diffusion Mechanisms in Amorphous Alloys.- 4.3 Theory of Diffusion in Disordered Media.- 4.3.1 The Effective-Medium Approximation.- 4.3.2 Explicite Solutions.- 4.3.3 The Effective-Medium Approximation for Direct Diffusion Mechanisms.- 4.3.4 Applications of the “Effective-Medium Approximation”.- 4.3.5 Molecular Dynamics Simulations and Diffusion Mechanisms.- 4.4 Diffusion of Hydrogen Isotopes and Light Particles in Amorphous Alloys.- 4.5 Magnetic After-Effects and Induced Anisotropies Due to Double-Well Systems in Amorphous Alloys.- 4.6 Viscosity and Internal Friction of Amorphous Alloys.- 4.6.1 Viscosity Measurements.- 4.6.2 Internal Friction Measurements.- Appendix: Microsectioning by Ion-Beam Sputtering — A Powerful Method to Determine Diffusion Profiles.- References.- 5 Mechanical Properties and Behaviour.- 5.1 Elastic and Anelastic Behaviour.- 5.2 Plastic Flow and Fracture Behaviour.- 5.3 Strength and Hardness.- 5.4 Fatigue and Wear Behaviour.- 5.5 Creep and Hot Deformation Behaviour.- References.- 6 Magnetic and Electronic Properties of Rapidly Quenched Materials.- 6.1 Rapidly Quenched Alloys.- 6.1.1 Amorphous Alloys.- 6.1.2 Nanocrystalline Alloys.- 6.2 Fundamental Magnetic Properties.- 6.2.1 Magnetic Moments and Curie Temperatures.- 6.2.2 Magnetic Anisotropy.- 6.2.3 Magnetostriction.- 6.3 Domains and Technical Properties of Amorphous Alloys.- 6.3.1 Domains.- 6.3.2 Coercivity.- 6.3.3 Magnetic Hardening.- 6.3.4 Induced Anisotropy.- 6.4 Magnetism and Short-Range Order.- 6.4.1 Ingredients of Short-Range Order.- 6.4.2 Random Local Anisotropy.- 6.5 Electronic Structure of Amorphous Alloys.- 6.5.1 Chemical Bonding.- 6.5.2 Split d Bands and p-d Bonding.- 6.5.3 Electron Transport.- 6.6 Applications.- 6.6.1 Distribution Transformers.- 6.6.2 Electronic Article Surveillance Sensors.- 6.6.3 Magnetic Recording Media.- 6.6.4 Permanent Magnets.- 6.7 Conclusion, Outlook.- References.- 7 Chemical Properties of Amorphous Alloys.- 7.1 Corrosion-Resistant Alloys in Aqueous Solutions.- 7.1.1 High Corrosion Resistance of Amorphous Fe-Cr Alloys.- 7.1.2 Factors Determining the High Corrosion Resistance of Amorphous Alloys.- a) High Activity of Amorphous Alloys.- b) Homogeneous Nature of Amorphous Alloys.- c) Beneficial Effect of Phosphorus in Amorphous Alloys.- 7.1.3 Recent Efforts in Tailoring Corrosion-Resistant Alloys.- a) Aluminum-Refractory Metal Alloys.- b) Chromium-Refractory Metal Alloys.- 7.2 Corrosion-Resistant Alloys at High Temperatures.- 7.3 Electrodes for Electrolysis of Aqueous Solutions.- 7.3.1 Electrode Materials.- 7.3.2 Preparation of Electrodes.- 7.4 Catalysts for Prevention of the Greenhouse Effect and Saving the Ozone Layer.- 7.4.1 CO2 Recycling.- 7.4.2 Catalysts for the Decomposition of NOx.- 7.4.3 Catalysts for the Decomposition of Chlorofluorocarbons.- 7.5 Concluding Remarks.- References.- 8 Selected Examples of Applications.- 8.1 Improvement of Mechanical Properties.- 8.1.1 Size Refinement.- 8.1.2 Extended Solid Solubility.- 8.1.3 Chemical Homogeneity.- 8.2. Magnetic Applications.- 8.2.1 Magnetic Properties and Applications.- 8.2.2 Power Magnetic Applications.- 8.2.3 Specialty Magnetic Applications.- 8.3 Joining Applications.- 8.4 Current Limitations and Future Directions.- Further Reading.- 9 Glossary of Important Terms.