Solidification of Containerless Undercooled Melts


Book Description

All metallic materials are prepared from the liquid state as their parent phase. Solidification is therefore one of the most important phase transformation in daily human life. Solidification is the transition from liquid to solid state of matter. The conditions under which material is transformed determines the physical and chemical properties of the as-solidified body. The processes involved, like nucleation and crystal growth, are governed by heat and mass transport. Convection and undercooling provide additional processing parameters to tune the solidification process and to control solid material performance from the very beginning of the production chain. To develop a predictive capability for efficient materials production the processes involved in solidification have to be understood in detail. This book provides a comprehensive overview of the solidification of metallic melts processed and undercooled in a containerless manner by drop tube, electromagnetic and electrostatic levitation, and experiments in reduced gravity. The experiments are accompanied by model calculations on the influence of thermodynamic and hydrodynamic conditions that control selection of nucleation mechanisms and modify crystal growth development throughout the solidification process.




Solidification of Containerless Undercooled Melts


Book Description

All metallic materials are prepared from the liquid state as their parent phase. Solidification is therefore one of the most important phase transformation in daily human life. Solidification is the transition from liquid to solid state of matter. The conditions under which material is transformed determines the physical and chemical properties of the as-solidified body. The processes involved, like nucleation and crystal growth, are governed by heat and mass transport. Convection and undercooling provide additional processing parameters to tune the solidification process and to control solid material performance from the very beginning of the production chain. To develop a predictive capability for efficient materials production the processes involved in solidification have to be understood in detail. This book provides a comprehensive overview of the solidification of metallic melts processed and undercooled in a containerless manner by drop tube, electromagnetic and electrostatic levitation, and experiments in reduced gravity. The experiments are accompanied by model calculations on the influence of thermodynamic and hydrodynamic conditions that control selection of nucleation mechanisms and modify crystal growth development throughout the solidification process.







Nucleation and the Properties of Undercooled Melts


Book Description

Nucleation is a central topic in Materials Science because it initiates most phase transformations. When a new phase appears within an existing phase, seeds must form before growth can occur within the given volume. The study of nucleation treats the very early stages, which involve only a limited number of atoms or molecules. It is a branch of fundamental research which has far-reaching implications for processes where nucleation is of paramount relevance to phase and microstructure selection. The development of any new material or processing route always leads to renewed interest in the topic.







Concepts in Physical Metallurgy


Book Description

The progress of civilization can be, in part, attributed to their ability to employ metallurgy. This book is an introduction to multiple facets of physical metallurgy, materials science, and engineering. As all metals are crystalline in structure, it focuses attention on these structures and how the formation of these crystals are responsible for certain aspects of the material's chemical and physical behaviour. Concepts in Physical Metallurgy also discusses the mechanical properties of metals, the theory of alloys, and physical metallurgy of ferrous and non-ferrous alloys.




Science of Sintering


Book Description

This volume, SCIENCE OF SINTERING: NEW DIRECTIONS FOR MATERIALS PROCESSING AND MICROSTRUCTURAL CONTROL, contains the edited Proceedings of the Seventh World Round Table Conference on Sintering, held in Herceg-Novi, Yugoslavia, Aug. 28 - Sept. 1, 1989. It was organized by the International Institute for the Science of Sintering (IISS), headquartered in Belgrade, Yugoslavia. Every fourth year since 1969, the Institute has organized such a Round Table Conference on Sintering; each has taken place at some selected location within Yugoslavia. A separate series of IISS Topical Sintering Symposia (Summer Schools) have also been held at four year intervals, but they have been offset by about two years, so they occur between the main Conferences. As a rule, the Topical Sintering Symposia have been devoted to more specific topics and they also take place in different countries. The aim of these Conferences and their related "Summer Schools" has been to bring together scientists from all over the world who work in various fields of science and technology concerned with sintering and sintered materials. A total of seven IISS Conferences have been held over the period 1969-1989, and they have been supplemented by the four Topical Sintering Symposia held in Yugoslavia, Poland, India and Japan (in 1975, 1979, 1983 and 1987, respectively). This most recent five day Conference addressed the fundamental scientific background as well as the technological state-of-the-art pertinent to science of sintering and high technology sintered materials.




Quasicrystals


Book Description

The book provides an introduction to all aspects of the physics of quasicrystals. The chapters, each written by an expert in this field, cover quasiperiodic tilings and the modeling of the atomic structure of quasicrystals. The electronic density of states and the calculation of the electronic structure play a key role in this introduction, as does an extensive discussion of the atomic dynamics. The study of defects in quasicrystals by high resolution electron microscopy and the computer simulations of defects and fracture in decorated tilings are important subjects for the application of these aperiodic crystals.




Solidification


Book Description

Solidification is one of the oldest processes for producing useful implements and remains one of the most important modern commercial processes. This text describes the fundamentals of the technology in a coherent way, using consistent notation.