Download or read book Thermodynamic Modeling and First principles Calculations of the Cr Hf Y Ternary System written by Bradley Hasek and published by . This book was released on 2010 with total page 78 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis describes the thermodynamic modeling of the ternary Cr-Hf-Y system. Chromium, hafnium, and yttrium are all used as alloying elements in nickel superalloys. Nickel superalloys usually contain many different alloying elements, so there becomes a need to understand the phase equilibria of large, multicomponent systems. This can be accomplished by using the CALPHAD method of modeling. CALPHAD modeling requires experimental data to better model the system. In the absence of experimental data, first-principles calculations can be used to predict thermochemical data. Before modeling the Cr-Hf-Y system, the binary Cr-Hf, Cr-Y, and Hf-Y systems must be modeled. In the Cr-Y and Hf-Y system, there is limited experimental data, so first-principles calculations are done on the BCC and HCP solid solution phases using special quasirandom structures (SQS's) to model the disordered systems. The symmetry is also investigated to ensure symmetry is not lost during relaxation. Using the first-principles calculations, the enthalpy of mixing is used to model these systems. The Cr-Hf system is modeled with experimental data and with first-principles calculations done on the Laves phase. With the three binary systems modeled, the ternary system is then modeled without any experimental data present. Isothermal sections are presented from 1273 K to 2200 K.

Download or read book First principles Calculations and Thermodynamic Modeling of the Hf Re Binary System with Extension to the Ni Hf Re Ternary System written by Yan Ling and published by . This book was released on 2011 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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.

Download or read book Ternary Alloys Based on III V Semiconductors written by Vasyl Tomashyk and published by CRC Press. This book was released on 2017-09-29 with total page 637 pages. Available in PDF, EPUB and Kindle. Book excerpt: III-V semiconductors have attracted considerable attention due to their applications in the fabrication of electronic and optoelectronic devices as light-emitting diodes and solar cells. Because of their wide applications in a variety of devices, the search for new semiconductor materials and the improvement of existing materials is an important field of study. This new book covers all known information about phase relations in ternary systems based on III-V semiconductors. This book will be of interest to undergraduate and graduate students studying materials science, solid state chemistry, and engineering. It will also be relevant for researchers at industrial and national laboratories, in addition to phase diagram researchers, inorganic chemists, and solid state physicists.

Download or read book Machine learning accelerated first principles predictions of the stability and mechanical properties of L12 strengthened cobalt based superalloys written by Shengkun Xi and published by OAE Publishing Inc.. This book was released on 2022-09-20 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: As promising next-generation candidates for applications in aero-engines, L12-strengthened cobalt (Co)-based superalloys have attracted extensive attention. However, the L12 strengthening phase in first-generation Co-Al-W-based superalloys is metastable, and both its solvus temperature and mechanical properties still need improvement. Therefore, it is necessary to discover new L12-strengthened Co-based superalloy systems with a stable L12 phase by exploring the effect of alloying elements on their stability. Traditional first-principles calculations are capable of providing the crystal structure and mechanical properties of the L12 phase doped by transition metals but suffer from low efficiency and relatively high computational costs. The present study combines machine learning (ML) with first-principles calculations to accelerate crystal structure and mechanical property predictions, with the latter providing both the training and validation datasets. Three ML models are established and trained to predict the occupancy of alloying elements in the supercell and the stability and mechanical properties of the L12 phase. The ML predictions are evaluated using first-principles calculations and the accompanying data are used to further refine the ML models. Our ML-accelerated first-principles calculation approach offers more efficient predictions of the crystal structure and mechanical properties for Co-V-Ta- and Co-Al-V-based systems than the traditional counterpart. This approach is applicable to expediting crystal structure and mechanical property calculations and thus the design and discovery of other advanced materials beyond Co-based superalloys.

Download or read book Ultra High Temperature Materials II written by Igor L. Shabalin and published by Springer. This book was released on 2019-04-24 with total page 755 pages. Available in PDF, EPUB and Kindle. Book excerpt: This exhaustive work in three volumes and over 1300 pages provides a thorough treatment of ultra-high temperature materials with melting points over 2500 °C. The first volume focuses on Carbon and Refractory Metals, whilst the second and third are dedicated solely to Refractory compounds and the third to Refractory Alloys and Composites respectively. Topics included are physical (crystallographic, thermodynamic, thermo physical, electrical, optical, physico-mechanical, nuclear) and chemical (solid-state diffusion, interaction with chemical elements and compounds, interaction with gases, vapours and aqueous solutions) properties of the individual physico-chemical phases of carbon (graphite/graphene), refractory metals (W, Re, Os, Ta, Mo, Nb, Ir) and compounds (oxides, nitrides, carbides, borides, silicides) with melting points in this range. It will be of interest to researchers, engineers, postgraduate, graduate and undergraduate students alike. The reader is provided with the full qualitative and quantitative assessment for the materials, which could be applied in various engineering devices and environmental conditions at ultra-high temperatures, on the basis of the latest updates in the field of physics, chemistry, materials science and engineering.

Download or read book Understanding oxidation resistance of Pt based alloys through computations of Ellingham diagrams with experimental verifications written by Xiaoyu Chong and published by OAE Publishing Inc.. This book was released on 2023-10-12 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thermodynamic calculations of Ellingham diagrams and the forming oxides have been performed relevant to the Pt-based alloys Pt82Al12M6 (M = Cr, Hf, Pt, and Ta). The predicted Ellingham diagrams indicate that the elements Hf and Al are easy to oxidize, followed by Ta and Cr, while Pt is extremely difficult to oxidize. Oxidation experiments characterized by X-ray diffraction (XRD) and electron probe micro-analyzers verify the present thermodynamic predictions, showing that the best alloy with superior oxidation resistance is Pt82Al12Cr6, followed by Pt88Al12 due to the formation of the dense and continuous α-Al2O3 scale on the surface of alloys; while the worse alloy is Pt82Al12Hf6 followed by Pt82Al12Ta6 due to drastic internal oxidation and the formation of deleterious HfO2, AlTaO4, and Ta2O5. The present work, combining computations with experimental verifications, provides a fundamental understanding and knowledgebase to develop Pt-based superalloys with superior oxidation resistance that can be used in ultra-high temperatures.

Download or read book Compendium of Phase Diagram Data written by Erwin Rudy and published by . This book was released on 1969 with total page 748 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Computational Thermodynamics written by Hans Lukas and published by . This book was released on 2007-07-12 with total page 342 pages. Available in PDF, EPUB and Kindle. Book excerpt: Phase diagrams are used in materials research and engineering to understand the interrelationship between composition, microstructure and process conditions. In complex systems, computational methods such as CALPHAD are employed to model thermodynamic properties for each phase and simulate multicomponent phase behavior. Written by recognized experts in the field, this is the first introductory guide to the CALPHAD method, providing a theoretical and practical approach. Building on core thermodynamic principles, this book applies crystallography, first principles methods and experimental data to computational phase behavior modeling using the CALPHAD method. With a chapter dedicated to creating thermodynamic databases, the reader will be confident in assessing, optimizing and validating complex thermodynamic systems alongside database construction and manipulation. Several case studies put the methods into a practical context, making this suitable for use on advanced materials design and engineering courses and an invaluable reference to those using thermodynamic data in their research or simulations.

Download or read book THERMODYNAMIC MODELING AND FIRST PRINCIPLES CALCULATIONS written by and published by . This book was released on 2005 with total page 83 pages. Available in PDF, EPUB and Kindle. Book excerpt: The increased application of quantum mechanical-based methodologies to the study of alloy stability has required a re-assessment of the field. The focus is mainly on inorganic materials in the solid state. In a first part, after a brief overview of the so-called ab initio methods with their approximations, constraints, and limitations, recommendations are made for a good usage of first-principles codes with a set of qualifiers. Examples are given to illustrate the power and the limitations of ab initio codes. However, despite the ''success'' of these methodologies, thermodynamics of complex multi-component alloys, as used in engineering applications, requires a more versatile approach presently afforded within CALPHAD. Hence, in a second part, the links that presently exist between ab initio methodologies, experiments, and CALPHAD approach are examined with illustrations. Finally, the issues of dynamical instability and of the role of lattice vibrations that still constitute the subject of ample discussions within the CALPHAD community are revisited in the light of the current knowledge with a set of recommendations.

Download or read book Methods for Phase Diagram Determination written by Ji-Cheng Zhao and published by Elsevier. This book was released on 2011-05-05 with total page 522 pages. Available in PDF, EPUB and Kindle. Book excerpt: Phase diagrams are "maps" materials scientists often use to design new materials. They define what compounds and solutions are formed and their respective compositions and amounts when several elements are mixed together under a certain temperature and pressure. This monograph is the most comprehensive reference book on experimental methods for phase diagram determination. It covers a wide range of methods that have been used to determine phase diagrams of metals, ceramics, slags, and hydrides. * Extensive discussion on methodologies of experimental measurements and data assessments * Written by experts around the world, covering both traditional and combinatorial methodologies* A must-read for experimental measurements of phase diagrams

Download or read book NASA Glenn Coefficients for Calculating Thermodynamic Properties of Individual Species written by Bonnie J. McBride and published by . This book was released on 2002 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Applied Computational Materials Modeling written by Guillermo Bozzolo and published by Springer Science & Business Media. This book was released on 2007-12-19 with total page 502 pages. Available in PDF, EPUB and Kindle. Book excerpt: The scope of this book is to identify and emphasize the successful link between computational materials modeling as a simulation and design tool and its synergistic application to experimental research and alloy development. The book provides a more balanced perspective of the role that computational modeling can play in every day research and development efforts. Each chapter describes one or more particular computational tool and how they are best used.

Download or read book Metals Abstracts written by and published by . This book was released on 1995 with total page 1602 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Order and Phase Stability in Alloys written by F. Ducastelle and published by North Holland. This book was released on 1991 with total page 536 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hardbound. The main purpose of this book is to describe the modern tools of solid state physics (in particular, electronic structure calculations and statistical thermodynamics) that enable us to understand ordering effects in alloys and to determine phase diagrams. This approach is used more to throw light on the most important physical mechanisms rather than to be able to make accurate predictions suitable for particular applications. On the other hand, more phenomenological, practically oriented approaches can expand the scope of these new theoretical insights. A second purpose of the book is to show that materials science can provide wonderful and too often ignored examples to test and discuss the most fundamental physical theories. For example, many real alloys on a face centered cubic lattice are marvellous examples of the Ising model on this lattice with many different ordered structures, commensurate or not.The text is therefore defi

Download or read book CALPHAD Calculation of Phase Diagrams A Comprehensive Guide written by N. Saunders and published by Elsevier. This book was released on 1998-06-09 with total page 497 pages. Available in PDF, EPUB and Kindle. Book excerpt: This monograph acts as a benchmark to current achievements in the field of Computer Coupling of Phase Diagrams and Thermochemistry, often called CALPHAD which is an acronym for Computer CALculation of PHAse Diagrams. It also acts as a guide to both the basic background of the subject area and the cutting edge of the topic, combining comprehensive discussions of the underlying physical principles of the CALPHAD method with detailed descriptions of their application to real complex multi-component materials. Approaches which combine both thermodynamic and kinetic models to interpret non-equilibrium phase transformations are also reviewed.

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.