Science and Technology of the Undercooled Melt
Science and Technology of the Undercooled Melt

Author: P.R. Sahm

Publisher: Springer Science & Business Media

Published: 2012-12-06

Total Pages: 296

ISBN-13: 940094456X

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"SCIENCE AND TECHNOLOGY OF '!HE UNDEROLED MELT" This title was chosen as the topical headline of the Advanced Research Workshop (ARW) from March 17 to 22 1985, held at the Castle of Theuern. The usual term "Rapid Solidification" is an overlapping description. Due to the fact that nucleation is so eminently important for the undercooling of a melt and this, in turn, is an important characteristic of rapid solidifi cation, undercooling plays an essential role in "rapid solidification." The undercooled melt has caused an "accelerated evolution" (if not a revolution) in materials science during the last decade. Several rather exciting concepts with interesting potential for novel applications are being pursued presently in various laboratories and companies. They concern not only new processes and ha~ware developments, but also present chal lenging perspectives for ventures, including the founding of new companies; or they promise growth possibilities with established larger and smaller industrial establishments.

Rapid Solidification of Undercooled Melts
Rapid Solidification of Undercooled Melts

Author: Xiaolong Xu

Publisher:

Published: 2018

Total Pages:

ISBN-13:

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Rapid solidification and microstructure evolution of deeply undercooled bulk concentrated Ni-20%at.Cu and Co-20%at.Pd alloys are strictly and systematically evaluated. First, thermodynamics of the undercooled melt is discussed. Consideration is provided for not only the systematic microstructure evolution within a broad undercooling range, but also the dendrite growth mechanism and the rapid solidification characteristics. The dendrite growth in the bulk undercooled melts was captured by a high speed camera. The first kind of grain refinement occurring in the low undercooling regimes was explained by a current grain refinement model. Besides for the dendrite melting mechanism, the stress originating from the solidification contraction and thermal strain in the first mushy zone during rapid solidification could be a main mechanism causing the second kind of grain refinement above the critical undercooling. This internal-stress led to the distortion and breakup of the primary dendrites and was semi-quantitatively described by a corrected stress accumulation model. It was found that the stress induced recrystallization could make the primary microstructures refine substantially after recalescence.

Solidification of Containerless Undercooled Melts
Solidification of Containerless Undercooled Melts

Author: Dieter M. Herlach

Publisher: John Wiley & Sons

Published: 2012-05-21

Total Pages: 569

ISBN-13: 3527647929

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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.

Metastable Solids from Undercooled Melts
Metastable Solids from Undercooled Melts

Author: Dieter Herlach

Publisher: Elsevier

Published: 2006-12-18

Total Pages: 445

ISBN-13: 0080468861

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This book presents the physical concepts and tools to characterize and describe the formation of metastable solids from undercooled melts. Its aim is to facilitate understanding of the development of the science and technology of solidification of melts and to introduce new concepts within this exciting research field in order to fulfil the challenges of the future in the field of undercooled melts. A comprehensive description of the science and applications of the undercooling phenomenon is given. It is composed of several main parts: experimental techniques for undercooling; characterization of the undercooled melt as the first step in rapid solidification; introducing the concepts of modern theories of rapid dendrite and eutectic growth and their comparison with experimental results, and a survey of metastable materials formed from the non-equilibrium state of an undercooled melt. * Showing clear links to possible application of results obtained from basic research * The subject matter is multidisciplinary and will be of interest to material scientists, physicists, physical chemists, mechanical and electrical engineers

Rapidly Quenched Metals
Rapidly Quenched Metals

Author: S Steeb

Publisher: Elsevier

Published: 2012-12-02

Total Pages: 1163

ISBN-13: 0444601112

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Rapidly Quenched Metals, Volume I covers the proceedings of the Fifth International Conference on Rapidly Quenched Metals, held in Wurzburg, Germany on September 3-7, 1984. The book focuses on amorphous and crystalline metals formed by rapid quenching from the melt. The selection first covers the scope and trends of developments in rapid solidification technology, rapid solidification, and undercooling of liquid metals by rapid quenching. Discussions focus on experimental method, powders, strip, particulate production, consolidation, and alloys and alloy systems. The text then examines the solidification of undercooled liquid alloys entrapped in solid; crystallization kinetics in undercooled droplets; and grain refinement in bulk undercooled alloys. The manuscript tackles the undercooling of niobium-germanium alloys in a 100 meter drop tube; influence of process parameters on the cooling rate of the meltspinning process; and the mechanism of ribbon formation in melt-spun copper and copper-zirconium. The formation and structure of thick sections of rapidly-solidified material by incremental deposition and production of ultrafine dispersions of rare earth oxides in Ti alloys using rapid solidification are also mentioned. The selection is a valuable reference for physicists, chemists, physical metallurgists, and engineers.

Rapidly Solidified Alloys
Rapidly Solidified Alloys

Author: Liebermann

Publisher: CRC Press

Published: 1993-05-20

Total Pages: 804

ISBN-13: 9780824789510

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This volume details the principles underlying rapid solidification processing, material structure and properties, and their applications. This practical resource presents a manifold approach to both amorphous and crystalline rapidly solidified metallic alloys.;Written by over 30 internationally acclaimed specialists in their respective fields, Rapidly Solidified Alloys: surveys nucleation and growth studies in undercooled melts; examines various processes for the production of rapidly solidified alloys; discusses the compaction of amorphous alloys; describes surface remelting treatments for the rapid solidification of surface layers and the resultant improved workpiece properties; covers the closely related topics of structural relaxation, atomic transport and other thermally induced processes; demonstrates microstructure-property relationships in rapidly quenched crystalline alloy systems and their beneficial effects in applications; and elucidates the basic, engineeering, and applications-oriented magnetic properties of amorphous alloys.;Furnishing more than 2300 literature citations for further study of specific subjects, Rapidly Solidified Alloys is intended for materials, mechanical, product, and civil engineers; metallurgists; magneticians; physicists; physical chemists; and graduate students in these disciplines.

Principles of Solidification
Principles of Solidification

Author: Martin Eden Glicksman

Publisher: Springer Science & Business Media

Published: 2010-12-17

Total Pages: 517

ISBN-13: 1441973443

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“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.