Download or read book A Study of the Kinetics of Phase Transformations in Nb Ti Al Alloys written by and published by . This book was released on 2000 with total page 183 pages. Available in PDF, EPUB and Kindle. Book excerpt: The solidification pathways, subsequent solid-state transformations and the liquidus sulface in the Nb-Ti Al system have been examined as part of a larger investigation of phase equilibria in Nb-Ti-Al intermetallic alloys. Fifteen alloys ranging in composition from 15 to 40 at. % Al, with Nb to Ti ratios of 4:l, 2:1,1.5:1,1:1 and 1:1.5 were prepared by arc-melting, and the as-cast microstructures were characterized by optical microscopy, microhardness, x-ray diffraction, differential thermal analysis, back-scattered electron imaging, electron probe microanalysis and transmission electron microscopy. The results indicate that the range of primary 3 solidification is much wider than that indicated in previously reported liquidus surfaces, both experimental and calculated Differential thermal analysis bas identified the existence of a 3 to y + 7transformation in three alloys where it was previously thought not to exist: confirmation was provided by high temperature vacuum heat treatments in the single-phase 3 region followed by rapid quenching. The location of the boundary between the 3, -Y and 6 primao solidification fields has been redefined. A massive /J-- 6 transformation, which was observed in the east microstructure of a Nb-25Ti-25AI alloy, was repeatable through cooling following homogenization. A 3-- > S+ cY eutectoid-like transformation in the 25 at. % Al alloys, was detected by differential thermal analysis and evaluated through microstructure analysis of heat treated samples. Trends in the 3phase with variations in composition were established for both lattice parameters and microhardness.

Download or read book Phase Transformations written by Srikumar Banerjee and published by Elsevier. This book was released on 2010-05-31 with total page 837 pages. Available in PDF, EPUB and Kindle. Book excerpt: The terms phase transitions and phase transformations are often used in an interchangeable manner in the metallurgical literature. In Phase Transformations, transformations driven by pressure changes, radiation and deformation and those occurring in nanoscale multilayers are brought to the fore. Order-disorder transformations, many of which constitute very good examples of continuous transformations, are dealt with in a comprehensive manner. Almost all types of phase transformations and reactions that are commonly encountered in inorganic materials are covered and the underlying thermodynamic, kinetic and crystallographic aspects elucidated. Shows readers the advancements in the field - due to enhanced computing power and superior experimental capability Drawing upon the background and the research experience of the authors, bringing together a wealth of experience Written essentially from a physical metallurgists view point

Download or read book A Study of Phase Transformations Microstructure and Mechanical Properties of Nb Al Alloys written by Sen-Shan Yang and published by . This book was released on 1992 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Phase Transformations in Metals and Alloys Third Edition Revised Reprint written by David A. Porter and published by CRC Press. This book was released on 1992-09-10 with total page 532 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the decade since the first edition of this popular text was published, the metallurgical field has undergone rapid developments in many sectors. Nonetheless, the underlying principles governing these developments remain the same. A textbook that presents these advances within the context of the fundamentals is greatly needed by instructors in the field Phase Transformations in Metals and Alloys, Second Edition maintains the simplicity that undergraduate instructors and students have come to appreciate while updating and expanding coverage of recently developed methods and materials. The book is effectively divided into two parts. The beginning chapters contain the background material necessary for understanding phase transformations - thermodynamics, kinetics, diffusion theory and the structure and properties of interfaces. The following chapters deal with specific transformations - solidification, diffusional transformation in solids and diffusionless transformation. Case studies of engineering alloys are incorporated to provide a link between theory and practice. New additions include an extended list of further reading at the end of each chapter and a section containing complete solutions to all exercises in the book Designed for final year undergraduate and postgraduate students of metallurgy, materials science, or engineering materials, this is an ideal textbook for both students and instructors.

Download or read book A Study of Phase Equilibria and Transformations in the Nb Ti Al System written by and published by . This book was released on 2000 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this project, research effort was directed into phase equilibria and transformations in the Nb-Ti-Al system and in multicomponent gamma titanium aluminides. The sequence of transformations site occupancies and stable phases in a 37Nb-37Ti-26Nb alloy were established, together with tie-lines at a number of temperatures between 1000 - 1300 deg C. The effect of beta-phase stabilizers, boron additions and thermal history on transformation pathways. modes, kinetics and microstructure in gamma Ti-Al alloys were established. Furthermore, isothermal and continuous cooling transformations for gamma alloys across a range of compositions from binary and ternary bases to multicomponent chemistries were studied. The reactions sequences for alpha and beta phases were quantified and partial CCT diagrams established for two multicomponent alloys. Mechanisms associated with various transformation modes are discussed.

Download or read book Gamma Titanium Aluminide Alloys written by Fritz Appel and published by John Wiley & Sons. This book was released on 2011-10-17 with total page 763 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first book entirely dedicated to the topic emphasizes the relation between basic research and actual processing technologies. As such, it covers complex microstructures down to the nanometer scale, structure/property relationships and potential applications in key industries. From the contents: * Constitution * Thermophysical Constants * Phase Transformations and Microstructures * Deformation Behaviour * Strengthening Mechanisms * Creep * Fracture Behaviour * Fatigue * Oxidation Resistance and Related Issues * Alloy Design * Ingot Production and Component Casting * Powder Metallurgy * Wrought Processing * Joining * Surface Hardening * Applications and Component Assessment

Download or read book Composition and temperature dependence of to phase transformation in Ti Nb alloys written by Yunting Su and published by OAE Publishing Inc.. This book was released on 2023-07-06 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: ω phases have shown great effects on the superelasticity and modulus of metastable β-Ti alloys. In this study, the microstructure evolution during cooling and aging for β → ω phase transformation is investigated by integrating a thermodynamic database with phase field simulations. Our CALPHAD calculations based on an available thermodynamic database give the Gibbs energies of metastable β (Nb-lean β1 + Nb-rich β2 produced via spinodal decomposition) and ω phases in Ti-Nb. Informed by the results, our phase field simulations show that the formation mechanisms of ω exhibit dependence on the composition and temperature. The ω can form in Ti-26 at.% Nb without the assistance of spinodal decomposition. Further analysis shows that the precursory spinodal decomposition in the β phase occurs in Ti-50 at.% Nb, and could induce geometrically confined ω. The novel transformation pathway could create unique morphology of ω. This study could elucidate new insights into the ω phase transformation in Ti-Nb alloys and metastable β-Ti alloys having spinodal decomposition.

Download or read book Statics and Dynamics of Alloy Phase Transformations written by Patrice E.A. Turchi and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 725 pages. Available in PDF, EPUB and Kindle. Book excerpt: The study of phase transformations in substitutional alloys, including order disorder phenomena and structural transformations, plays a crucial role in understanding the physical and mechanical properties of materials, and in designing alloys with desired technologically important characteristics. Indeed, most of the physical properties, including equilibrium properties, transport, magnetic, vibrational as well as mechanical properties of alloys are often controlled by and are highly sensitive to the existence of ordered compounds and to the occurrence of structural transformations. Correspondingly, the alloy designer facing the task of processing new high-performance materials with properties that meet specific industrial applications must answer the following question: What is the crystalline structure and the atomic configuration that an alloy may exhibit at given temperature and concentration? Usually the answer is sought in the phase-diagram of a relevant system that is often determined experimentally and does not provide insight to the underlying mechanisms driving phase stability. Because of the rather tedious and highly risky nature of developing new materials through conventional metallurgical techniques, a great deal of effort has been expended in devising methods for understanding the mechanisms contrOlling phase transformations at the microscopic level. These efforts have been bolstered through the development of fully ab initio, accurate theoretical models, coupled with the advent of new experimental methods and of powerful supercomputer capabilities.

Download or read book Phase Transformations in Metals and Alloys Revised Reprint written by David A. Porter and published by CRC Press. This book was released on 2009-02-10 with total page 538 pages. Available in PDF, EPUB and Kindle. Book excerpt: Expanded and revised to cover developments in the field over the past 17 years, and now reprinted to correct errors in the prior printing, Phase Transformation in Metals and Alloys, Third Edition provides information and examples that better illustrate the engineering relevance of this topic. It supplies a comprehensive overview of specific types o

Download or read book The Study of the Beta to Gamma Phase Transformation in High nb Ti al nb Alloys written by Sonalika Goyel and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This research was aimed at the nature of the beta-to-gamma phase transformation, including its kinetics, effects of composition, grain boundaries, and surfaces-both internal and external. Further, in order to inhibit the formation of gamma-phase upon quenching the beta-phase, the influence of Cr-a beta-stabilizer-and the effects of boron segregation were also studied. This research shows that the beta grain boundaries always act as the preferred nucleation sites for gamma-phase formation upon quenching as well as during slower cooling. The gamma-phase was observed to form with a Widmanstätten lath morphology at all temperatures and cooling rates, including high temperatures and slow cooling rates. In the absence of any grain boundaries, the sample surfaces act as the preferred nucleation sites for the Widmanstätten gamma-phase. The gamma-phase was observed to nucleate in two distinct stages upon cooling at relatively slower rates, and produced two morphologies: 1) Widmanstätten laths and 2) a plate-like gamma-phase morphology. The sigma-phase did not form upon slow cooling to room temperature, as was predicted by thermodynamic calculations. Aging a quenched beta-phase, however, yielded a gamma+sigma microstructure. It was noted that additions of as little as 1.5 at% Cr could drastically reduce the gamma-phase volume fraction, primarily by slowing its growth rate. Alloys with low amounts of boron additions were studies to investigate the effect of beta grain boundary 'poisoning' on gamma-phase formation upon quenching. Boron additions were shown to increase the nucleation rate of the gamma-phase at the beta-phase grain boundaries.

Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1976 with total page 680 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Study of the beta to alpha Phase Transformation in Ti 25 35 Al Alloys written by Uwe Pilchowski and published by . This book was released on 1999 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Phase Transformations in Metals and Alloys written by David A. Porter and published by CRC Press. This book was released on 2021-11-07 with total page 591 pages. Available in PDF, EPUB and Kindle. Book excerpt: Revised to reflect recent developments in the field, Phase Transformation in Metals and Alloys, Fourth Edition, continues to be the most authoritative and approachable resource on the subject. It supplies a comprehensive overview of specific types of phase transformations, supplemented by practical case studies of engineering alloys. The book’s unique presentation links a basic understanding of theory with application in a gradually progressive yet exciting manner. Based on the authors’ teaching notes, the text takes a pedagogical approach and provides examples for applications and problems that can be readily used for exercises. NEW IN THE FOURTH EDITION 40% of the figures and 30% of the text Insights provided by numerical modelling techniques such as ab initio, phase field, cellular automaton, and molecular dynamics Insights from the application of advanced experimental techniques, such as high-energy X-ray diffraction, high-resolution transmission electron microscopy, scanning electron microscopy, combined with electron backscattered diffraction New treatment of ternary phase diagrams and solubility products The concept of paraequilibrium in systems containing highly mobile interstitial elements Thermodynamics of grain boundaries and the influence of segregation on grain boundary diffusion Reference to software tools for solving diffusion problems in multicomponent systems Introduction to concepts related to coincident site lattices and methods for determining the dislocation content of grain boundaries and interfaces Updated treatment of coherency and interface structure including the important fcc–bcc interfaces Treatment of metallic glasses expanded to cover critical cooling rate Austin–Rickets equation introduced as an alternative to the Avrami equation in the case of precipitation kinetics Discussion of the effects of overlap in nucleation, growth and coarsening Discussion of pearlite and bainite transformations updated Entirely new and extensive treatment of diffusionless martensitic transformations covering athermal and thermally activated martensite in ferrous systems as well as shape memory, superelasticity and rubber-like behavior in ordered nonferrous alloys New practical applications covering spinodal alloys, fir-tree structures in aluminum castings, Al–Cu–Li aerospace alloys, superelastic and shape memory alloys, quenched and partitioned steels, advanced high-strength steels and martensitic stainless steels Each chapter now concludes with a summary of the main points References to scientific publications and suggestions for further reading updated to reflect experimental and computational advances Aimed at students studying metallurgy and materials science and engineering, the Fourth Edition retains the previous editions’ popular easy-to-follow style and excellent mix of basic and advanced information, making it ideal for those who are new to the field. A new solutions manual and PowerPoint figure slides are available to adopting professors.

Download or read book Phase Transitions in Solids Under High Pressure written by Vladimir Davydovich Blank and published by CRC Press. This book was released on 2013-10-25 with total page 455 pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of high-pressure techniques has become popular for studying the nature of substances and phenomena occurring in them, especially as a means of obtaining new materials (synthesis under high pressure) and processing known materials (hydroextrusion). A product of many years of research by the authors and their colleagues, Phase Transitions in Solids under High Pressure discusses the relationships of phase transformations in solids under high pressure, the mechanism of these transformations, crystal geometry, the effect of deformation, the conditions of formation, and preservation of the high-pressure phases under normal pressure. The book begins with an introduction that describes the relationship of the thermodynamics of phase transformations and the kinetics of the transformations. This is followed by a chapter explaining the equipment and mostly original procedures for investigating phase transformation in solids under high hydrostatic and quasi-hydrostatic pressures. The book covers phase transformations under high pressure in a wide temperature range in the elements carbon, silicon, germanium, titanium, zirconium, iron, gallium, and cerium as well as in titanium- and iron-based alloys and AIBVII, AIIBVI, and AIIIBV compounds. In addition, the book examines the kinetics of phase transformations in iron-based alloys in isobaric–isothermal conditions. The authors present results for phase transformations in deformation under high pressure, describe several non-trivial effects associated with phase transformations under high pressure, and analyze the kinetics and hysteresis of high-temperature and low-temperature phase transformations. They conclude by describing the role of investigations under high pressure for determining general relationships governing phase transformations in solids.

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 892 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Materials Properties Handbook written by Gerhard Welsch and published by ASM International. This book was released on 1993-12-31 with total page 1206 pages. Available in PDF, EPUB and Kindle. Book excerpt: Comprehensive datasheets on more than 60 titanium alloys More than 200 pages on metallurgy and fabrication procedures Input from more than 50 contributors from several countries Careful editorial review for accuracy and usefulness. Materials Properties Handbook: Titanium Alloys provides a data base for information on titanium and its alloys, and the selection of specific alloys for specific applications. The most comprehensive titanium data package ever assembled provides extensive information on applications, physical properties, corrosion, mechanical properties (including design allowances where available), fatigue, fracture properties, and elevated temperature properties. The appropriate specifications for each alloy are included. This international effort has provided a broad information base that has been compiled and reviewed by leading experts within the titanium industry, from several countries, encompassing numerous technology areas. Inputs have been obtained from the titanium industry, fabricators, users, government and academia. This up-to-date package covers information from almost the inception of the titanium industry, in the 1950s, to mid-1992. The information, organized by alloy, makes this exhaustive collection an easy-to-use data base at your fingertips, which generally includes all the product forms for each alloy. The 60-plus data sheets supply not only extensive graphical and tabular information on properties, but the datasheets also describe or illustrate important factors which would aid in the selection of the proper alloy or heat treatment. The datasheets are further supplemented with back-ground information on the metallurgy and fabrication characteristics of titanium alloys. An especially extensive coverage of properties, processing and metallurgy is provided in the datasheet for the workhorse of the titanium industry, Ti-6Al-4V. This compendium includes the newest alloys made public. even those still under development. In many cases, key references are included for further information on a given subject. Comprehensive datasheets provide extensive information on: Applications, Specifications, Corrosion, Mechanical Design Properties, Fatigue and Fracture

Download or read book Journal of Research of the National Institute of Standards and Technology written by and published by . This book was released on 1990 with total page 824 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reports NIST research and development in the physical and engineering sciences in which the Institute is active. These include physics, chemistry, engineering, mathematics, and computer sciences. Emphasis on measurement methodology and the basic technology underlying standardization.