Bulk Nanostructured Materials: Fundamentals and Applications

Helps readers move from laboratory-scale research to industrial applications In recent years, the development of bulk nanostructured materials has become one of the most promising research directions in materials science. Bulk nanostructured materials can provide new and unusual properties for a wide range of different metals and alloys, such as very high strength and ductility, record-breaking fatigue endurance, or increased superplastic forming capabilities and many others. With bulk nanostructured materials moving from laboratory-scale research to industrial applications, the full potential of this research area is beginning to emerge. Bulk Nanostructured Materials sets the stage for further innovation by providing a single treatise that encapsulates the fundamentals as well as new and emerging applications based on severe plastic deformation (SPD) processing. The book presents and analyzes the most recent results in bulk nanostructured materials research as well as new trends in SPD developments. Special emphasis is placed on the mechanical properties, functional behavior, and innovative applications of bulk nanostructured materials formed by severe plastic deformation. Bulk Nanostructured Materials is divided into five parts: Part One: Introduction, Definition and Concept of Bulk Nanomaterials Part Two: High Pressure Torsion Processing Part Three: Equal-Channel Angular Pressing Part Four: Fundamentals and Properties of Materials after SPD Part Five: Innovation Potential and Prospects for SPD Applications Figures throughout the book clarify complex concepts and techniques. In addition, detailed examples help readers bridge the gap from theory to practical applications. By drawing together the fundamentals and techniques in the field, Bulk Nanostructured Materials makes it possible for students and professionals in nanotechnology and materials research to create new bulk nanostructured materials with a broad range of useful industrial applications.

List of Symbols and Abbreviations Preface 1. Introduction 2. Description of severe plastic deformation: principles and techniques 2.1. A historical retrospective of SPD processing 2.2. Main techniques for severe plastic deformation 2.3. SPD processing regimes for grain refinement 2.4. Types of nanostructures from severe plastic deformation PART ONE: High–Pressure Torsion 3. Principles and technical parameters of high–pressure torsion 3.1. A history of high pressure deformation 3.2. Definition of the strain imposed in HPT 3.3. The principles of unconstrained and constrained HPT 3.4. Variation in homogeneity across an HPT disk 3.5. Influence of applied load and accumulated strain on microstructural evolution 3.6. Influence of strain hardening and dynamic recovery 3.7. Significance of slippage during high pressure torsioning 3.8. Models for the development of homogeneity in HPT metals 4. HPT processing of metals, alloys and composites 4.1. Microstructure evolution and grain refinement in metals subjected to HPT 4.2. The processing of solid solutions and multiphase alloys 4.3. Processing of intermetallics by HPT 4.4. Processing of metal matrix composites 5. New approaches to HPT processing 5.1. Cyclic processing by reversing the direction of torsional straining 5.2. Using HPT for the cold–consolidation of powders and machining chips 5.3. The extension of HPT to large samples PART TWO: Equal Channel Angular Pressing 6. The development of processing using equal–channel angular pressing 6.1. Construction of an ECAP/ECAE facility 6.2. Equal channel angular pressing of rods, bars and plate samples 6.3. Alternative procedures for achieving ECAP: rotary dies, side–extrusion and multi–pass dies 6.4. Developing ECAP with parallel channels 6.5. Continuous processing by ECAP: from continuous confined strip shearing, equal–channel angular drawing and co–shearing to conform process 7. Fundamental parameters and experimental factors in ECAP 7.1. The strain imposed in equal channel angular pressing 7.2. The processing routes in ECAP 7.3. The shearing patterns associated with ECAP 7.4. Experimental factors influencing ECAP 7.5. The role of internal heating during ECAP 7.6. Influence of a back–pressure 8. Grain refinement in metallic systems processed by ECAP 8.1. Mezoscopic characteristics after ECAP 8.2. The development of an ultrafine–grained microstructure 8.3. Factors governing the ultrafine grain size in ECAP = 8.4. Microstructural features and texture after ECAP 8.5. Influence of ECAP on precipitation 8.6. The pressing of multi–phase alloys and composites 8.7. Consolidation by ECAP = 8.8. Post–ECAP processing = PART THREE: Fundamentals and properties of materials after SPD 9. Structural modeling and physical properties of SPD processed materials 9.1. Experimental studies of defect in BNM 9.2. Developments of structural model 9.3. Fundamental studies and physical properties 10. Mechanical properties of BNM at ambient temperature 10.1. Strength and “superstrength” 10.2. Plastic deformation and ductility 10.3. Fatigue behavior 10.4. Alternative deformation mechanisms at very small grain sizes 11. Mechanical properties of BNM at high temperatures 11.1. Achieving superplasticity in ultrafine–grained (UFG) metals 11.2. Effects of different ECAP processing routes on superplasticity 11.3. Developing a superplastic forming capability 11.4. Cavitation in superplasticity after SPD 11.5. Future prospects for superplasticity in nanostructured materials 12. Functional and multifunctional properties of bulk nanostructured materials 12.1. Corrosion behavior 12.2. Wear resistance 12.3. Enhanced strength and conductivity 12.4. Biomedical behavior of nanometals 12.5. Enhanced magnetic properties 12.6. Inelasticity and shape–memory effects 12.7. Another functional properties PART FOUR: Innovation Potential and Prospects for SPD applications 13. Innovation potential of bulk nanostructured materials 13.1. Nano–titanium and Ti alloys for medical implants 13.2. Nanostructured Mg alloys for hydrogen storage 13.3. Microdevices from BNM 13.4. Innovation potential and application of nanostructured Al alloys 13.5. Fabrication of nanostructured steels for engineering 14. Conclusion remarks

RUSLAN Z. VALIEV, PhD, is Professor and Director of the Institute of Physics of Advanced Materials at Ufa State Aviation Technical University. He is also Head of Laboratory on Mechanics of Bulk Nanomaterials at St. Petersburg State University and Chairman of the International NanoSPD Steering Committee (www.nanospd.org). ALEXANDER P. ZHILYAEV, PhD, is Principal Research Scientist for the Institute for Metals Superplasticity at the Russian Academy of Sciences. He is also Senior Research Fellow on the Faculty of Engineering and the Environment at the University of Southampton. TERENCE G. LANGDON, PhD, is Professor of Materials Science at the University of Southampton. He is also the William E. Leonhard Professor of Engineering at the University of Southern California and founding member of the International NanoSPD Steering Committee. The authors, through their numerous pioneering studies, have played a major role in the development and use of SPD techniques to process bulk nanostructured materials.