Mechanical Properties of Nanocrystalline Materials


Book Description

This book concentrates on both understanding and development of nanocrystalline materials. The original relation that connects grain size and strength, known as the Hall-Petch relation, is studied in the nanometer grain size region. The breakdown of such a relation is a challenge. Why and how to overcome it? Is the dislocation mechanism still operating when the grain size is very small, approaching the amorphous limit? How do we go from the microstructure information to the continuum description of the mechanical properties?




Nanocrystalline Materials


Book Description

In the monograph, the first of this type in the world, the authors discuss systematically the current state of investigations into nanocrystalline materials. The experimental results on the effect of the nanocrystalline state on the microstructure and the mechanical, thermophysical, optical, and magnetic properties of metals, alloys and solid-phase compounds are generalised. Special attention is given to the main methods of production of isolated nanoparticles, ultrafine powders and dense nanocrystalline materials. The dimensional effects in isolated nanoparticles and high-density nanocrystalline materials are discussed in detail, and the important role of the interface in the formation of the structure and properties of dense nanocrystalline materials is shown. The modelling considerations, explaining special features of the structure and anomalous properties of substances in the nanocrystalline condition, are analysed.




Structural Nanocrystalline Materials


Book Description

Nanocrystalline materials exhibit exceptional mechanical properties, representing an exciting new class of structural materials for technological applications. The advancement of this important field depends on the development of new fabrication methods, and an appreciation of the underlying nano-scale and interface effects. This authored book addresses these essential issues, presenting for the first time a fundamental, coherent and current account at the theoretical and practical level of nanocrystalline and nanocomposite bulk materials and coatings. The subject is approached systematically, covering processing methods, key structural and mechanical properties, and a wealth of applications. This is a valuable resource for graduate students studying nanomaterials science and nanotechnologies, as well as researchers and practitioners in materials science and engineering.




Mechanical Properties of Nanocrystalline Materials


Book Description

This book concentrates on both understanding and development of nanocrystalline materials. The original relation that connects grain size and strength, known as the Hall-Petch relation, is studied in the nanometer grain size region. The breakdown of such a relation is a challenge. Why and how to overcome it? Is the dislocation mechanism still opera




On the Hardening and Softening of Nanocrystalline Materials


Book Description

Nanocrystalline Pd and Cu samples have been thermally treated to determine whether the relation between hardness and grain size depend on the method used to vary the grain sizes. Previous reports indicate that hardening with decreasing grain size resulted from data obtained using individual samples, while softening with decreasing grain size resulted from data from a given sample that had been thermally treated. Hardening and softening regimes were evident for the nanocrystalline cu, and the hardness improvements over the original as-consolidated state were maintained throughout the thermal treatments. This review examines our hardness results for Cu and Pd and those for other nanocrystalline materials.




Mechanical Properties and Deformation Behavior of Materials Having Ultra-Fine Microstructures


Book Description

In an attempt to meet the demand for new ultra-high strength materials, the processing of novel material configurations with unique microstructure is being explored in systems which are further and further from equilibrium. One such class of emerging materials is the so-called nanophased or nanostructured materials. This class of materials includes metals and alloys, ceramics, and polymers characterized by controlled ultra-fine microstructural features in the form oflayered, fibrous, or phase and grain distribution. While it is clear that these materials are in an early stage of development, there is now a sufficient body of literature to fuel discussion of how the mechanical properties and deformation behavior can be controlled through control of the microstructure. This NATO-Advanced Study Institute was convened in order to assess our current state of knowledge in the field of mechanical properties and deformation behavior in materials with ultra fine microstructure, to identify opportunities and needs for further research, and to identify the potential for technological applications. The Institute was the first international scientific meeting devoted to a discussion on the mechanical properties and deformation behavior of materials having grain sizes down to a few nanometers. Included in these discussions were the topics of superplasticity, tribology, and the supermodulus effect. Lectures were also presented which covered a variety of other themes including synthesis, characterization, thermodynamic stability, and general physical properties.




Amorphous-Nanocrystalline Alloys


Book Description

Amorphous-nanocrystalline alloys are a relatively new class of materials born from the rapid development of new technologies and different methods of producing amorphous and nanocrystalline powders and films, compacting, melt quenching, megaplastic deformation, implantation, laser, plasma, and other high-energy methods. This book considers methods of producing these materials (melt quenching, controlled crystallization, deformation effect, and pulse treatments (photon, laser and ultrasound), spraying thin films, and ion implantation). Theoretical and experimental studies describe plastic deformation mechanisms and physico-mechanical properties. Practical applications are also presented.




Amorphous and Nanocrystalline Materials


Book Description

Amorphous and nanocrystalline materials are a class of their own. Their properties are quite different to those of the corresponding crystalline materials. This book gives systematic insight into their physical properties, structure, behaviour, and design for special advanced applications.




Amorphous-Nanocrystalline Alloys


Book Description

Amorphous-nanocrystalline alloys are a new class of materials born at the turn of the 20th and 21st centuries as a result of the rapid development of new technologies and, in particular, nanotechnology They arose at the intersection of intensive research and development of promising amorphous and nanocrystalline materials. In terms of the level of physical and mechanical properties, two-phase amorphous-nanocrystalline materials in some cases exceed the properties of both nanocrystalline and amorphous materials, thereby creating a noticeable synergistic effect. In this book, the methods of obtaining amorphous-crystalline materials (quenching from a melt, controlled crystallization, deformation effect, pulsed [photon, laser and ultrasonic] treatment thin film deposition, and ion implantation) are considered successively. Detailed information is then given on the structural features of the transition from the amorphous phase state to the nanocrystalline state under thermal and deformation effects. Theoretical and experimental studies are analyzed in which the mechanisms of plastic deformation and the features of the emerging physico-mechanical properties are described. The authors then go on to describe areas of practical application of amorphous-nanocrystalline alloys. This book is a comprehensive resource for specialists in materials, science and nanotechnology, specifically researchers studying crystalline and amorphous materials as it highlights the various properties that are important for practical use. Book jacket.