Order and Phase Stability in Alloys


Book Description

Hardbound. The main purpose of this book is to describe the modern tools of solid state physics (in particular, electronic structure calculations and statistical thermodynamics) that enable us to understand ordering effects in alloys and to determine phase diagrams. This approach is used more to throw light on the most important physical mechanisms rather than to be able to make accurate predictions suitable for particular applications. On the other hand, more phenomenological, practically oriented approaches can expand the scope of these new theoretical insights. A second purpose of the book is to show that materials science can provide wonderful and too often ignored examples to test and discuss the most fundamental physical theories. For example, many real alloys on a face centered cubic lattice are marvellous examples of the Ising model on this lattice with many different ordered structures, commensurate or not.The text is therefore defi




Structural and Phase Stability of Alloys


Book Description

This vohune contains the papers presented at the Adriatico Research Conference on Structural and Phase Stability of Alloys held in Trieste, Italy, in May 1991, under the auspices of the International Centre for Theoretical Physics. The conference brought together participants with a variety of interests in theoretical and experimental aspects of alloys from Argentina, Belgium, Bulgaria, Czechslovakia, France, Germany, Italy, Japan, Mexico, People's Republic of Congo,Portugal, Switzerland, United Kingdom, United States, U. S. S. R. , and Venezuela. The conference was purposely designed to succinctly cover experimental and the oretical aspects of magnetic and non-magnetic alloys, surfaces, thin films and nanos tructures. The Conference opened with an overview of a select class of advanced structural materials, with a potential in engineering applications, for which the con ventional "physics" approach, both theoretical and experimental, should have a sig nificant impact. A number of papers were dedicated to the use of phenomenological approaches for the description of thermodynamic bulk and surface properties. It was clear from these presentations that the phenomenological models and simulations in alloy theory have reached a high degree of sophistication. Although with somewhat limited predictive powers, the phenomenological models provide a valuable tool for the understanding of a variety of subtle phenomena such as short-range order, phase stability, kinetics and the thermodynamics of surfaces and antiphase boundaries, to name a few.










Alloy Phase Stability


Book Description

One of the ultimate goals of materials research is to develop a fun damental and predictive understanding of the physical and metallurgical properties of metals and alloys. Such an understanding can then be used in the design of materials having novel properties or combinations of proper ties designed to meet specific engineering applications. The development of new and useful alloy systems and the elucidation of their properties are the domain of metallurgy. Traditionally, the search for new alloy systems has been conducted largely on a trial and error basis, guided by the skill and intuition of the metallurgist, large volumes of experimental data, the principles of 19th century thermodynamics and ad hoc semi-phenomenological models. Recently, the situation has begun to change. For the first time, it is possible to understand the underlying mechanisms that control the formation of alloys and determine their properties. Today theory can begin to offer guidance in predicting the properties of alloys and in developing new alloy systems. Historically, attempts directed toward understanding phase stability and phase transitions have proceeded along distinct and seemingly diverse lines. Roughly, we can divide these approaches into the following broad categories. 1. Experimental determination of phase diagrams and related properties, 2. Thermodynamic/statistical mechanical approaches based on semi phenomenological models, and 3. Ab initio quantum mechanical methods. Metallurgists have traditionally concentrated their efforts in cate gories 1 and 2, while theoretical physicists have been preoccupied with 2 and 3.




High-Entropy Alloys


Book Description

This book provides a systematic and comprehensive description of high-entropy alloys (HEAs). The authors summarize key properties of HEAs from the perspective of both fundamental understanding and applications, which are supported by in-depth analyses. The book also contains computational modeling in tackling HEAs, which help elucidate the formation mechanisms and properties of HEAs from various length and time scales.




Structure and Properties of High-Entropy Alloys


Book Description

This book provides an overview of high entropy alloys, explaining all the basics of this new class of materials that emerged at the beginning of the 21st: It begins with the basics of the manufacturing methods of high entropy alloys and discusses the mechanical properties and deformation mechanisms of high entropy alloys. Then the book addresses the stability of these alloys and explores the prospects of high entropy alloys for applications.This book is intended as an introduction for physicists and materials scientists who need to become familiar with high entropy alloys.




From Hamiltonians to Phase Diagrams


Book Description

The development of the modern theory of metals and alloys has coincided with great advances in quantum-mechanical many-body theory, in electronic structure calculations, in theories of lattice dynamics and of the configura tional thermodynamics of crystals, in liquid-state theory, and in the theory of phase transformations. For a long time all these different fields expanded quite independently, but now their overlap has become sufficiently large that they are beginning to form the basis of a comprehensive first-principles the ory of the cohesive, structural, and thermodynamical properties of metals and alloys in the crystalline as well as in the liquid state. Today, we can set out from the quantum-mechanical many-body Hamiltonian of the system of electrons and ions, and, following the path laid out by generations of the oreticians, we can progress far enough to calculate a pressure-temperature phase diagram of a metal or a composition-temperature phase diagram of a binary alloy by methods which are essentially rigorous and from first prin ciples. This book was written with the intention of confronting the materials scientist, the metallurgist, the physical chemist, but also the experimen tal and theoretical condensed-matter physicist, with this new and exciting possibility. Of course there are limitations to such a vast undertaking as this. The selection of the theories and techniques to be discussed, as well as the way in which they are presented, are necessarily biased by personal inclination and personal expertise.




High-Entropy Materials


Book Description

This book draws on the latest research to discuss the history and development of high-entropy alloys and ceramics in bulk, film, and fiber form. High-entropy materials have recently been developed using the entropy of mixing and entropy of configuration of materials, and have proven to exhibit unique properties superior to those of conventional materials. The field of high-entropy alloys was born in 2004, and has since been developed for both scientific and engineering applications. Although there is extensive literature, this field is rapidly transforming. This book highlights the cutting edge of high-entropy materials, including their fundamentals and applications. Above all, it reflects two major milestones in their development: the equi-atomic ratio single-phase high-entropy alloys; and the non-equi-atomic ratio dual-phase high-entropy alloys.




Hume-Rothery Rules for Structurally Complex Alloy Phases


Book Description

With a history that reaches back some 90 years, the Hume-Rothery rules were developed to provide guiding principles in the search for new alloys. Ultimately, the rules bridged metallurgy, crystallography, and physics in a way that led to the emergence of a physics of the solid state in 1930s, although the physical implications of the rules were nev