Download or read book Solidification at the High and Low Rate Extreme written by Halim Meco and published by . This book was released on 2004 with total page 398 pages. Available in PDF, EPUB and Kindle. Book excerpt: The microstructure selection at both high and low growth rates is studied. For the high rate extreme, melt spinning of a Fe-Si-B alloy is employed. The microstructural variations with changing wheel speed and factors affecting these variations are examined through various characterization techniques. Particular attention was given for the influence of melt pool behavior on the competition between nucleation of crystalline solidification products and glass formation. It is found that there exists a window of wheel speeds which give rise to a stable melt-pool and production of amorphous ribbons. The surface-controlled melt-pool oscillation is found as the dominant factor governing the onset of unsteady thermal conditions accompanied by varying amounts of crystalline nucleation observed near the lower wheel speed limit. For the upper wheel speed limit, a criterion based on mass-balance and momentum transfer is developed for predicting the window of wheel speeds for obtaining uniform and fully amorphous ribbons. For the low rate extreme, solidification and morphological selection of the faceted silicon phase is investigated in a near eutectic Al-Si system by utilizing a Bridgman type directional solidification unit. Particularly, the role of certain defect mechanisms, namely twinning, in the selection of microstructure and growth crystallography is investigated. At the imposed growth rates of 0.5 and 1 micron/s and temperature gradient of 7.5 K/mm, a unique silicon morphology consisting of 8-pointed stars is observed to grow with 001 texture within continuous domains across the sample. The growth crystallography of this unique silicon structure is characterized and it is found that substantial amount of [210] type twinning exists within the central core of this star-shaped morphology. It is found that the twinning phenomenon at the core is an essential feature for branching, morphological selection, and adjustment of spacing between the star-like silicon features. These mechanisms and the associated growth characteristics are examined in detail.
Download or read book Solidification at the High and Low Rate Extreme written by and published by . This book was released on 2004 with total page 207 pages. Available in PDF, EPUB and Kindle. Book excerpt: The microstructures formed upon solidification are strongly influenced by the imposed growth rates on an alloy system. Depending on the characteristics of the solidification process, a wide range of growth rates is accessible. The prevailing solidification mechanisms, and thus the final microstructure of the alloy, are governed by these imposed growth rates. At the high rate extreme, for instance, one can have access to novel microstructures that are unattainable at low growth rates. While the low growth rates can be utilized for the study of the intrinsic growth behavior of a certain phase growing from the melt. Although the length scales associated with certain processes, such as capillarity, and the diffusion of heat and solute, are different at low and high rate extremes, the phenomena that govern the selection of a certain microstructural length scale or a growth mode are the same. Consequently, one can analyze the solidification phenomena at both high and low rates by using the same governing principles. In this study, we examined the microstructural control at both low and high extremes. For the high rate extreme, the formation of crystalline products and factors that control the microstructure during rapid solidification by free-jet melt spinning are examined in Fe-Si-B system. Particular attention was given to the behavior of the melt pool at different quench-wheel speeds. Since the solidification process takes place within the melt-pool that forms on the rotating quench-wheel, we examined the influence of melt-pool dynamics on nucleation and growth of crystalline solidification products and glass formation. High-speed imaging of the melt-pool, analysis of ribbon microstructure, and measurement of ribbon geometry and surface character all indicate upper and lower limits for melt-spinning rates for which nucleation can be avoided, and fully amorphous ribbons can be achieved. Comparison of the relevant time scales reveals that surface-controlled melt-pool oscillation may be the dominant factor governing the onset of unsteady thermal conditions accompanied by varying amounts of crystalline nucleation observed near the lower limit. At high quench-wheel velocities, the influence of these oscillations is minimal due to very short melt-pool residence times. However, microstructural evidence suggests that the entrapment of gas pockets at the wheel-metal interface plays a critical role in establishing the upper rate limit. An observed transition in wheel-side surface character with increasing melt-spinning rate supports this conclusion.
Download or read book Fundamentals of Aluminium Metallurgy written by Roger Lumley and published by Elsevier. This book was released on 2010-11-25 with total page 862 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aluminium is an important metal in manufacturing, due to its versatile properties and the many applications of both the processed metal and its alloys in different industries. Fundamentals of aluminium metallurgy provides a comprehensive overview of the production, properties and processing of aluminium, and its applications in manufacturing industries. Part one discusses different methods of producing and casting aluminium, covering areas such as casting of alloys, quality issues and specific production methods such as high-pressure diecasting. The metallurgical properties of aluminium and its alloys are reviewed in Part two, with chapters on such topics as hardening, precipitation processes and solute partitioning and clustering, as well as properties such as fracture resistance. Finally, Part three includes chapters on joining, laser sintering and other methods of processing aluminium, and its applications in particular areas of industry such as aerospace. With its distinguished editor and team of expert contributors, Fundamentals of aluminium metallurgy is a standard reference for researchers in metallurgy, as well as all those involved in the manufacture and use of aluminium products. Provides a comprehensive overview of the production, properties and processing of aluminium, and its applications in manufacturing industries Considers many issues of central importance in aluminium production and utilization considering quality issues and design for fatigue growth resistance Metallurgical properties of aluminium and its alloys are further explored with particular reference to work hardening and applications of industrial alloys
Download or read book Metal Matrix Composites written by C.T. Lynch and published by CRC Press. This book was released on 2018-01-18 with total page 181 pages. Available in PDF, EPUB and Kindle. Book excerpt: The concept of reinforcing a material by the use of a fiber is not a new one. The Egyptian brick layer employed the same principle more than three thousand years ago when straw was incorporated into the bricks. More recent examples of fiber reinforced composites are steel-reinforced concrete, nylon and rayon cord reinforced tires, and fiberglass reinforced plastics. In the last several years considerable progress has been made on new composite structures particularly utilizing boron (on tungsten substrate) fibers in various matrices. Many of these advances have been reviewed recently by P. M. Sinclair1 and by Alexander, Shaver, and Withers.2 An excellent earlier survey is available by Rauch Sutton, and McCreight.3 Boron-reinforced epoxy composites are being fabricated and tested as jet engine components, fuselage components, and even as a complete aircraft wing because of the tremendous gain in experimentally demonstrated properties such as modulus, strength, and fatigue resistance, particularly on a weight normalized (e.g., strength/density) basis. Other than glass/epoxy and boron/ epoxy composites and perhaps boron/aluminum, the systems now under study are in the early stages of research and development. These include other boron/metal composites, graphite/polymer, graphite/metal, graphite/graphite, alumina/metal, and aligned eutectic (directionally, solidified) combinations. As Sinclair points out, designers are wary about filamentary composites becausethere is little background information and scant experience.
Download or read book Solidification written by Michel Rappaz and published by EPFL Press. This book was released on 2009-08-21 with total page 656 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Solidification written by Jonathan A. Dantzig and published by EPFL Press. This book was released on 2016-11-18 with total page 711 pages. Available in PDF, EPUB and Kindle. Book excerpt: Solidification is one of the oldest processes for producing complex shapes for applications ranging from art to industry, and remains as one of the most important commercial processes for many materials. Since the 1980s, numerous fundamental developments in the understanding of solidification processes and microstructure formation have come from both analytical theories and the application of computational techniques using commonly available powerful computers. This book integrates these developments in a comprehensive volume that also presents and places them in the context of more classical theories. This second edition highlights the key concepts within each chapter to help guide the reader through the most important aspects of the topics. The figures are now in color, in order to improve the visualization of phenomena and concepts. Recent important developments in the field since the first edition was published have also been added. The three-part text is aimed at graduate and professional engineers. The first part, Fundamentals and Macroscale Phenomena, presents the thermodynamics of solutions and then builds on that subject to motivate and describe equilibrium phase diagrams. Transport phenomena are discussed next, focusing on the issues of most importance to liquid-solid phase transformations, then moving on to describing in detail both analytical and numerical approaches to solving such problems. The second part, Microstructure, employs these fundamental concepts for the treatment of nucleation, dendritic growth, microsegregation, eutectic and peritectic solidification, and microstructure competition. This part concludes with a chapter describing the coupling of macro- and microscopic phenomena in microstructure development. The third and final part describes various types of Defects that may occur, with emphasis on porosity, hot tearing and macrosegregation, presented using the modeling tools and microstructure descriptions developed earlier.
Download or read book High temperature alloys for gas turbines and other applications 1986 written by W. Betz and published by Springer Science & Business Media. This book was released on 1987-12-01 with total page 880 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Principles of Solidification written by Martin Eden Glicksman and published by Springer Science & Business Media. This book was released on 2010-12-17 with total page 517 pages. Available in PDF, EPUB and Kindle. Book excerpt: “Principles of Solidification” offers comprehensive descriptions of liquid-to-solid transitions encountered in shaped casting, welding, and non-biological bulk crystal growth processes. The book logically develops through careful presentation of relevant thermodynamic and kinetic theories and models of solidification occurring in a variety of materials. Major topics encompass the liquid-state, liquid-solid transformations, chemical macro- and microsegregation, purification by fractional crystallization and zone refining, solid-liquid interfaces, polyphase freezing, and rapid solidification processing. Solid-liquid interfaces are discussed quantitatively both as sharp and diffuse entities, with supporting differential geometric descriptions. The book offers: • Detailed mathematical examples throughout to guide readers • Applications of solidification and crystal growth methodologies for preparation and purification of metals, ceramics, polymers and semiconductors • Appendices providing supporting information on special topics covered in the chapters. Readers in materials, metallurgical, chemical, and mechanical engineering will find this to be a useful source on the subjects of solidification and crystal growth. Chemists, physicists, and geologists concerned with melting/freezing phenomena will also find much of value in this book.
Download or read book Microjoining and Nanojoining written by Y N Zhou and published by Elsevier. This book was released on 2008-03-27 with total page 835 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many important advances in technology have been associated with nanotechnology and the miniaturization of components, devices and systems. Microjoining has been closely associated with the evolution of microelectronic packaging, but actually covers a much broader area, and is essential for manufacturing many electronic, precision and medical products.Part one reviews the basics of microjoining, including solid-state bonding and fusion microwelding. Part two covers microjoining and nanojoining processes, such as bonding mechanisms and metallurgy, process development and optimization, thermal stresses and distortion, positioning and fixturing, sensing, and numerical modelling. Part three discusses microjoining of materials such as plastics, ceramics, metals and advanced materials such as shape memory alloys and nanomaterials. The book also discusses applications of microjoining such as joining superconductors, the manufacture of medical devices and the sealing of solid oxide fuel cells.This book provides a comprehensive overview of the fundamental aspects of microjoining processes and techniques. It is a valuable reference for production engineers, designers and researchers using or studying microjoining technologies in such industries as microelectronics and biomedical engineering. Reviews the basics of nanojoining including solid-state bonding and fusion microwelding Covers microjoining and nanojoining processes such as bonding mechanisms and metallurgy, sensing and numerical modelling Examines applications of microjoining such as the manufacturing of medical devices, and the sealing of solid oxide fuel cells
Download or read book Proceedings of the Symposium on the Solidification and Long Term Storage of Highly Radioactive Wastes written by W. H. Regan and published by . This book was released on 1966 with total page 896 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Theoretical Analysis of Diffusion of Solutes During the Solidification of Alloys written by Carl Wagner and published by . This book was released on 1953 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fundamentals of Alloy Solidification Applied to Industrial Processes written by and published by . This book was released on 1984 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt: Solidification processes and phenomena, segregation, porosity, gravity effects, fluid flow, undercooling, as well as processing of materials in the microgravity environment of space, now available on space shuttle flights were discussed.
Download or read book Solidification of Containerless Undercooled Melts written by Dieter M. Herlach and published by John Wiley & Sons. This book was released on 2012-05-21 with total page 569 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Rapid Solidification of Metals and Alloys written by Howard Jones and published by Ashgate Publishing. This book was released on 1983 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Elements of Rapid Solidification written by Monde A. Otooni and published by Springer Science & Business Media. This book was released on 2013-03-08 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt: Elements of Rapid Solidification: Fundamentals and Applications is the product of many years of concentrated work in the field of rapid solidification and processing. This quasi-monograph is unique in two ways. It brings together the talent of many international scientists in an effort to focus attention on all aspects of a new scientific field and it concentrates on fundamentals and practical applications. Simply stated, this book has been written by the senior students in the field of rapid solidification technology for the new generation of solid-state physicists, materials scientists, materials engineers, metallurgists and ceramicists.
Download or read book Welding Metallurgy and Weldability written by John C. Lippold and published by John Wiley & Sons. This book was released on 2014-11-24 with total page 418 pages. Available in PDF, EPUB and Kindle. Book excerpt: Describes the weldability aspects of structural materials used in a wide variety of engineering structures, including steels, stainless steels, Ni-base alloys, and Al-base alloys Welding Metallurgy and Weldability describes weld failure mechanisms associated with either fabrication or service, and failure mechanisms related to microstructure of the weldment. Weldability issues are divided into fabrication and service related failures; early chapters address hot cracking, warm (solid-state) cracking, and cold cracking that occur during initial fabrication, or repair. Guidance on failure analysis is also provided, along with examples of SEM fractography that will aid in determining failure mechanisms. Welding Metallurgy and Weldability examines a number of weldability testing techniques that can be used to quantify susceptibility to various forms of weld cracking. Describes the mechanisms of weldability along with methods to improve weldability Includes an introduction to weldability testing and techniques, including strain-to-fracture and Varestraint tests Chapters are illustrated with practical examples based on 30 plus years of experience in the field Illustrating the weldability aspects of structural materials used in a wide variety of engineering structures, Welding Metallurgy and Weldability provides engineers and students with the information needed to understand the basic concepts of welding metallurgy and to interpret the failures in welded components.
Download or read book Low Carbon Stabilization and Solidification of Hazardous Wastes written by Daniel C.W. Tsang and published by Elsevier. This book was released on 2021-09-24 with total page 592 pages. Available in PDF, EPUB and Kindle. Book excerpt: Low Carbon Stabilization and Solidification of Hazardous Wastes details sustainable and low-carbon treatments for addressing environmental pollution problems, critically reviewing low-carbon stabilization/solidification technologies. This book presents the latest state-of-the-art knowledge of low-carbon stabilization/solidification technologies to provide cost-effective sustainable solutions for real-life environmental problems related to hazardous wastes including contaminated sediments. As stabilization/solidification is one of the most widely used waste remediation methods for its versatility, fast implementation and final treatment of hazardous waste treatment, it is imperative that those working in this field follow the most recent developments. Low Carbon Stabilization and Solidification of Hazardous Wastes is a necessary read for academics, postgraduates, researchers and engineers in the field of environmental science and engineering, waste management, and soil science, who need to keep up to date with the most recent advances in low-carbon technologies. This audience will develop a better understanding of these low-carbon mechanisms and advanced characterization technologies, fostering the future development of low-carbon technologies and the actualization of green and sustainable remediation. Focuses on stabilization/solidification for environmental remediation, as one of the most widely used environmental remediation technologies in field-scale applications Details the most advanced and up-to-date low-carbon sustainable technologies necessary to guide future research and sustainable development Provides comprehensive coverage of low-carbon solutions for treating a variety of hazardous wastes as well as contaminated soil and sediment
