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Book Transformation Crystallography and Plasticity of the Delta to Alpha Prime Transformation in Plutonium Alloys

Download or read book Transformation Crystallography and Plasticity of the Delta to Alpha Prime Transformation in Plutonium Alloys written by A. J. Schwartz and published by . This book was released on 2003 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: In delta phase Pu-Ga alloys, the transformation from the ductile face-centered cubic (fcc) {delta} phase that is retained at room temperature to the brittle low-temperature monoclinic alpha' phase is a thermally activated diffusionless transformation with double-c kinetics. Accurate modeling of the phase transformation requires detailed understanding of the role of plastic flow during the transformation and of the crystallographic transformation path. Using transmission electron microscopy (TEM), we find a significant increase in dislocation density in {delta} near the {alpha}' plates, which suggests that plastic deformation contributes to the accommodation of the 20% reduction in volume during the transformation. Analysis of a series of optical micrographs of partially transformed alloys suggests that the {alpha}' habit plane is usually nearly perpendicular to 111 {delta}. However, a small number of TEM observations support a habit plane near 112 or 123, in agreement with earlier work.

Book Burst like Characteristics of the Delta alpha prime Phase Transformation in Pu Ga Alloys

Download or read book Burst like Characteristics of the Delta alpha prime Phase Transformation in Pu Ga Alloys written by Alfred Schwartz and published by . This book was released on 2003 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: The {delta} to {alpha}' phase transformation in Pu-Ga alloys is intriguing for both scientific and technological reasons. On cooling, the ductile fcc d-phase transforms martensitically to the brittle monoclinic {alpha}'-phase at approximately -120 C (depending on composition). This exothermic transformation involves a 20% volume contraction and a significant increase in resistivity. The reversion of {alpha}' to {delta} involves a large temperature hysteresis beginning just above room temperature. In an attempt to better understand the underlying thermodynamics and kinetics responsible for these unusual features, we examined the {delta}/{alpha}' transformations in a 0.6 wt% Pu-Ga alloy using differential scanning calorimetry (DSC) and resistometry. Both techniques indicate that the martensite start temperature is -120 C and the austenite start temperature is 35 C. The heat of transformation is approximately 3 kJ/mole. During the {alpha}' {yields} {delta} reversion, ''spikes'' and ''steps'' are observed in DSC and resistometry scans, respectively. These spikes and steps are periodic, and their periodicity with respect to temperature does not vary with heating rate. With an appropriate annealing cycle, including a ''rest'' at room temperature, these spikes and steps can be reproduced through many thermal cycles of a single sample.

Book Delta Alpha Prime Phase Transformations in a Pu Ga Alloy

Download or read book Delta Alpha Prime Phase Transformations in a Pu Ga Alloy written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In pure plutonium, the monoclinic [alpha] phase is the equilibrium phase at ambient temperature and pressure. The addition of a few percent of gallium, however, allows the fcc [delta] phase to be retained metastablely at ambient conditions. When the metastable [delta] phase is cooled to subambient temperatures, it partially transforms to the monoclinic [alpha]' phase, which has gallium supersaturated in the lattice. The [alpha]' phase reverts to the [delta] phase when the sample is heated above the ambient temperature. The martensite burst (M[sub b]) and reversion start (R[sub s]) temperatures are functions of the composition, heating rate, and prior thermal history. For a Pu-2.0 at% Ga alloy, the transformation hysteresis is approximately 150 C, which is large compared with other solid-solid phase transformations. Both the forward and reverse transformations are martensitic and proceed via a burst mode. Here, we use differential scanning calorimetry (DSC) and resistometry to perform fundamental studies of the [alpha]'/[delta] transformations with the goal of understanding how aging may affect [delta] phase stability, particularly the M[sub b] temperature. Because materials properties of the [alpha]' and [delta] phases are considerably different (including a density increase of 25% and an accompanying resistivity increase of 46% upon transformation from [delta] to [alpha]'), unexpected transformation to the [alpha]' phase is of particular interest to the stockpile stewardship community.

Book Pressure Induced delta to alpha Phase Transformations in a Pu Ga Alloy

Download or read book Pressure Induced delta to alpha Phase Transformations in a Pu Ga Alloy written by and published by . This book was released on 2009 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Computational Thermodynamics of Materials

Download or read book Computational Thermodynamics of Materials written by Zi-Kui Liu and published by Cambridge University Press. This book was released on 2016-06-30 with total page 261 pages. Available in PDF, EPUB and Kindle. Book excerpt: Integrates fundamental concepts with experimental data and practical applications, including worked examples and end-of-chapter problems.

Book Complex Inorganic Solids

Download or read book Complex Inorganic Solids written by Patrice E. A. Turchi and published by Springer Science & Business Media. This book was released on 2007-12-31 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the key aspects of this volume is to cut across the traditional taxonomy of disciplines in the study of alloys. Hence there has been a deliberate attempt to integrate the different approaches taken towards alloys as a class of materials in different fields, ranging from geology to metallurgical engineering. The emphasis of this book is to highlight commonalities between different fields with respect to how alloys are studied. The topics in this book fall into several themes, which suggest a number of different classification schemes. We have chosen a scheme that classifies the papers in the volume into the categories Microstructural Considerations, Ordering, Kinetics and Diffusion, Magnetic Considerations and Elastic Considerations. The book has juxtaposed apparently disparate approaches to similar physical processes, in the hope of revealing a more dynamic character of the processes under consideration. This monograph will invigorate new kinds of discussion and reveal challenges and new avenues to the description and prediction of properties of materials in the solid state and the conditions that produce them.

Book Nickel and Its Alloys

Download or read book Nickel and Its Alloys written by Samuel Jacob Rosenberg and published by . This book was released on 1968 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Chemical Thermodynamics of Zirconium

Download or read book Chemical Thermodynamics of Zirconium written by and published by Elsevier. This book was released on 2005-12-06 with total page 545 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume is part of the series on "Chemical Thermodynamics", published under the aegis of the OECD Nuclear Energy Agency. It contains a critical review of the literature on thermodynamic data for inorganic compounds of zirconium. A review team, composed of five internationally recognized experts, has critically reviewed all the scientific literature containing chemical thermodynamic information for the above mentioned systems. The results of this critical review carried out following the Guidelines of the OECD NEA Thermochemical Database Project have been documented in the present volume, which contains tables of selected values for formation and reaction thermodynamical properties and an extensive bibliography. * Critical review of all literature on chemical thermodynamics for compounds and complexes of Zr.* Tables of recommended Selected Values for thermochemical properties* Documented review procedure* Exhaustive bibliography* Intended to meet requirements of radioactive waste management community* Valuable reference source for the physical, analytical and environmental chemist.

Book Thermochemistry of Alloys

Download or read book Thermochemistry of Alloys written by H. Brodowsky and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 579 pages. Available in PDF, EPUB and Kindle. Book excerpt: The thermochemistry of alloys has interested generations of scientists and the subject was treated in classical textbooks long ago, e.g. by Hume-Rothery, by Wagner, and by Kubaschewski and Alcock. Nevertheless, the appearance of new materials and the desire to improve traditional materials and metallurgical processes has kept up demand for more information on the thermodynamics of these systems. The advent of computing power has created new opportunities to tie various aspects and properties together, such as phase diagrams and thermodynamic functions, that are in principle thermodynamically inter related but were too cumbersome to work out before. The computer has also been a powerful tool in buUding and testing models that help to explain the underlying causes of non-ideal behavior. At the same time, these calculations have pinpointed areas, where additional and more accurate data are needed. In the laboratory, new methods, improved materials, and sophistica ted instrumentation have gradually changed the way in which experiments are done. Within the time span of perhaps thirty years, the development went from jotting down individual readings of data points to strip chart recording to automatic digital data acquisition. Scholars and students active in the field of "Thermochemistry of Alloys" convened for a NATO Advanced Study Institute at Kiel in August 1987 to discuss these developments. This book collects most of the lectures and seminar papers given at the Institute.

Book Manufacturing and Application of Stainless Steels

Download or read book Manufacturing and Application of Stainless Steels written by Andrea Di Schino and published by MDPI. This book was released on 2020-04-15 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: Stainless steels represent a quite interesting material family, both from a scientific and commercial point of view, following to their excellent combination in terms of strength and ductility together with corrosion resistance. Thanks to such properties, stainless steels have been indispensable for the technological progress during the last century and their annual consumption increased faster than other materials. They find application in all these fields requiring good corrosion resistance together with ability to be worked into complex geometries. Despite to their diffusion as a consolidated materials, many research fields are active regarding the possibility to increase stainless steels mechanical properties and corrosion resistance by grain refinement or by alloying by interstitial elements. At the same time innovations are coming from the manufacturing process of such a family of materials, also including the possibility to manufacture them starting from metals powder for 3D printing. The Special Issue scope embraces interdisciplinary work covering physical metallurgy and processes, reporting about experimental and theoretical progress concerning microstructural evolution during processing, microstructure-properties relations, applications including automotive, energy and structural.

Book Materials Issues for Generation IV Systems

Download or read book Materials Issues for Generation IV Systems written by Véronique Ghetta and published by Springer Science & Business Media. This book was released on 2008-04-23 with total page 596 pages. Available in PDF, EPUB and Kindle. Book excerpt: Global warming, shortage of low-cost oil resources and the increasing demand for energy are currently controlling the world's economic expansion while often opposing desires for sustainable and peaceful development. In this context, atomic energy satisfactorily fulfills the criteria of low carbon gas production and high overall yield. However, in the absence of industrial fast-breeders the use of nuclear fuel is not optimal, and the production of high activity waste materials is at a maximum. These are the principal reasons for the development of a new, fourth generation of nuclear reactors, minimizing the undesirable side-effects of current nuclear energy production technology while increasing yields by increasing operation temperatures and opening the way for the industrial production of hydrogen through the decomposition of water. The construction and use of such reactors is hindered by several factors, including performance limitations of known structural materials, particularly if the life of the projected systems had to extend over the periods necessary to achieve low costs (at least 60 years). This book collects lectures and seminars presented at the homonymous NATO ASI held in autumn 2007 at the Institut d’Etudes Scientifiques in Cargèse, France. The adopted approach aims at improving and coordinating basic knowledge in materials science and engineering with specific areas of condensed matter physics, the physics of particle/matter interaction and of radiation damage. It is our belief that this methodology is crucially conditioning the development and the industrial production of new structural materials capable of coping with the requirements of these future reactors.

Book Thermodynamics and Kinetics of Phase Transformations Volume 398

Download or read book Thermodynamics and Kinetics of Phase Transformations Volume 398 written by James S. Im and published by . This book was released on 1996-09-10 with total page 714 pages. Available in PDF, EPUB and Kindle. Book excerpt: The emphasis of this book is on the quantitative analysis of transformation kinetics, integrated with thermodynamics. Solidification is a success story for quantitative kinetics analysis. The work reported concentrates on phase selection under extreme processing - large undercooling or ultrarapid quenching - of the liquid. Theoretical treatments are concerned mainly with the analysis of morphological instabilities during directional solidification at more conventional rates. The coverage of particle-beam effects is distinguished by the materials studied: alkali halides, minerals, semiconductors and metals. The thermodynamics of interfaces are a particular focus, especially in connection with the solid-state formation of amorphous phases. A highlight of the book is the coverage of the Johnson-Mehl-Avrami-Kolmogorov analysis of overall transformation kinetics. This venerable treatment is revisited and new insights and limitations are explored. Topics include: transformations in undercooled liquids; directional solidification; particle beam-induced transformations; interfaces - thermodynamics and reactions; amorphous materials - structure and transformations; solid-state transformations and ordering and phase separation.

Book The Chemical Bond in Inorganic Chemistry

Download or read book The Chemical Bond in Inorganic Chemistry written by Ian David Brown and published by . This book was released on 2002 with total page 289 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes the bond valence model, a description of acid-base bonding which is becoming increasingly popular particularly in fields such as materials science and mineralogy where solid state inorganic chemistry is important. Recent improvements in crystal structure determination have allowed the model to become more quantitative. Unlike other models of inorganic chemical bonding, the bond valence model is simple, intuitive, and predictive, and can be used for analysing crystal structures and the conceptual modelling of local as well as extended structures. This is the first book to explore in depth the theoretical basis of the model and to show how it can be applied to synthetic and solution chemistry. It emphasizes the separate roles of the constraints of chemistry and of three-dimensional space by analysing the chemistry of solids. Many applications of the model in physics, materials science, chemistry, mineralogy, soil science, surface science, and molecular biology are reviewed. The final chapter describes how the bond valence model relates to and represents a simplification of other models of inorganic chemical bonding.