Download or read book Atomistic Modelling and Prediction of Glass Forming Ability in Bulk Metallic Glasses written by Sina Sedighi and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Prediction and Verification of the Glass Forming Ability in Bulk Metallic Glasses written by and published by . This book was released on 2014 with total page 111 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Bulk Metallic Glasses written by Michael Miller and published by Springer. This book was released on 2010-11-04 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bulk metallic glasses are a new emerging field of materials with many desirable and unique properties. These amorphous materials have many diverse applications from structural applications to biomedical implants. This book provides a complete overview of bulk metallic glasses. It covers the principles of alloy design, glass formation, processing, atomistic modeling, computer simulations, mechanical properties and microstructures.

Download or read book Bulk Metallic Glasses written by C. Suryanarayana and published by CRC Press. This book was released on 2017-11-22 with total page 549 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reflecting the fast pace of research in the field, the Second Edition of Bulk Metallic Glasses has been thoroughly updated and remains essential reading on the subject. It incorporates major advances in glass forming ability, corrosion behavior, and mechanical properties. Several of the newly proposed criteria to predict the glass-forming ability of alloys have been discussed. All other areas covered in this book have been updated, with special emphasis on topics where significant advances have occurred. These include processing of hierarchical surface structures and synthesis of nanophase composites using the chemical behavior of bulk metallic glasses and the development of novel bulk metallic glasses with high-strength and high-ductility and superelastic behavior. New topics such as high-entropy bulk metallic glasses, nanoporous alloys, novel nanocrystalline alloys, and soft magnetic glassy alloys with high saturation magnetization have also been discussed. Novel applications, such as metallic glassy screw bolts, surface coatings, hyperthermia glasses, ultra-thin mirrors and pressure sensors, mobile phone casing, and degradable biomedical materials, are described. Authored by the world’s foremost experts on bulk metallic glasses, this new edition endures as an indispensable reference and continues to be a one-stop resource on all aspects of bulk metallic glasses.

Download or read book Thermodynamic Prediction of Glass Formation Tendency Cluster in jellium Model for Metallic Glasses Ab Initio Tight binding Calculations and New Density Functional Theory Development for Systems with Strong Electron Correlation written by and published by . This book was released on 2009 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt: Solidification of liquid is a very rich and complicated field, although there is always a famous homogeneous nucleation theory in a standard physics or materials science text book. Depending on the material and processing condition, liquid may solidify to single crystalline, polycrystalline with different texture, quasi-crystalline, amorphous solid or glass (Glass is a kind of amorphous solid in general, which has short-range and medium-range order). Traditional oxide glass may easily be formed since the covalent directional bonded network is apt to be disturbed. In other words, the energy landcape of the oxide glass is so complicated that system need extremely long time to explore the whole configuration space. On the other hand, metallic liquid usually crystalize upon cooling because of the metallic bonding nature. However, Klement et.al., (1960) reported that Au-Si liquid underwent an amorphous or "glassy" phase transformation with rapid quenching. In recent two decades, bulk metallic glasses have also been found in several multicomponent alloys[Inoue et al., (2002)]. Both thermodynamic factors (e.g., free energy of various competitive phase, interfacial free energy, free energy of local clusters, etc.) and kinetic factors (e.g., long range mass transport, local atomic position rearrangement, etc.) play important roles in the metallic glass formation process. Metallic glass is fundamentally different from nanocrystalline alloys. Metallic glasses have to undergo a nucleation process upon heating in order to crystallize. Thus the short-range and medium-range order of metallic glasses have to be completely different from crystal. Hence a method to calculate the energetics of different local clusters in the undercooled liquid or glasses become important to set up a statistic model to describe metalllic glass formation. Scattering techniques like x-ray and neutron have widely been used to study the structues of metallic glasses. Meanwhile, computer simulation also plays an important role, as it may directly track the movement of every atom. Simulation time is a major limit for molecular dynamics, not only because of "slow" computer speed, but also because of the accumulation error in the numerical treatment of the motion equations. There is also a great concern about the reliability of the emperical potentials if using classical molecular dynamics. Ab initio methods based on density functional theory(DFT) do not have this problem, however, it suffers from small simulation cells and is more demanding computationally. When crystal phase is involved, size effect of the simulation cell is more pronounced since long-range elastic energy would be established. Simulation methods which are more efficient in computation but yet have similar reliability as the ab initio methods, like tight-binding method, are highly desirable. While the complexity of metallic glasses comes from the atomistic level, there is also a large field which deals with the complexity from electronic level. The only "ab initio" method applicable to solid state systems is density functional theory with local density approximation(LDA) or generalized gradient approximation(GGA) for the exchange-correlation energy. It is very successful for simple sp element, where it reaches an high accuracy for determining the surface reconstruction. However, there is a large class of materials with strong electron correlation, where DFT based on LDA or GGA fails in a fundamental way. An "ab initio" method which can generally apply to correlated materials, as LDA for simple sp element, is still to be developed. The thesis is prepared to address some of the above problems.

Download or read book Bulk Metallic Glasses written by C. Suryanarayana and published by CRC Press. This book was released on 2011-06-03 with total page 686 pages. Available in PDF, EPUB and Kindle. Book excerpt: In spite of the large amount of research activity in this subfield of materials science and engineering, there is no single book available that provides background information, methods of synthesis, characterization procedures, properties, and potential and existing applications.of bulk metallic glasses. Written in an easy-to-understand style by pioneering researchers in this field, Bulk Metallic Glasses is one of the first books to coherently discuss the synthesis, processing, properties, and applications of these unique materials. The book explores the differences between nanocrystalline, glassy, and amorphous solids as well as the thermodynamics and kinetics and various processing methods of glass formation. It critically compares the different criteria for glass formation, describes the advantages and limitations of experimental methods for synthesizing bulk metallic glasses in assorted sizes and shapes, and examines the kinetics of crystallization/devitrification and the mechanisms of transformations. It also covers the density, diffusivity, thermal expansion, electrical resistivity, specific heat, viscosity, corrosion resistance, mechanical behavior, and magnetic properties of bulk metallic glasses. After presenting a wide array of applications, the book concludes with a discussion on the future of these materials. The adoption of bulk metallic glasses into existing systems is besieged by many obstacles but due to their interesting combination of properties, future applications may be unlimited. A one-stop resource on all aspects of bulk metallic glasses, this book demonstrates the immense potential of these novel materials. It clearly elucidates the background, detailed methods of synthesis and characterization, structure, and properties of bulk metallic glasses.

Download or read book Metallic Glasses written by Behrooz Movahedi and published by BoD – Books on Demand. This book was released on 2016-08-17 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metallic glasses and amorphous materials have attracted much more attention in the last two decades. A noncrystalline solid produced by continuous cooling from the liquid state is known as a glass. From the other point of view, a noncrystalline material, obtained by any other process, for example, vapor deposition or solid-state processing methods such as mechanical alloying, but not directly from the liquid state, is referred to as an amorphous material. At this moment, bulk metallic glasses (BMG) are appearing as a new class of metallic materials with unique physical and mechanical properties for structural and functional usage. Extreme values of strength, fracture toughness, magnetic properties, corrosion resistance, and other properties have been registered in BMG materials.

Download or read book Alloys and Intermetallic Compounds written by Cristina Artini and published by CRC Press. This book was released on 2017-07-12 with total page 267 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on the role of modeling in the design of alloys and intermetallic compounds. It includes an introduction to the most important and most used modeling techniques, such as CALPHAD and ab-initio methods, as well as a section devoted to the latest developments in applications of alloys. The book emphasizes the correlation between modeling and technological developments while discussing topics such as wettability of Ultra High Temperature Ceramics by metals, active brazing of diamonds to metals in cutting tools, surface issues in medicine, novel Fe-based superconductors, metallic glasses, high entropy alloys, and thermoelectric materials.

Download or read book General Correspondence D written by William Harold Davidson and published by . This book was released on 1952 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Thermodynamic Prediction of Glass Formation Tendency Cluster in jellium Model for Metallic Glasses Ab Initio Tight binding Calculations and New Density Functional Theory Development for Systems with Strong Electron Correlation written by Yongxin Yao and published by . This book was released on 2009 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt: We have calculated the T0 curves for several Al-Rare Earth (RE) binary alloys and compared the results with reported observations of glass formation (T0 curve is defined as a trajectory in temperature-composition space where the liquid phase and solid phase have same Gibbs free energies), in order to assess the importance of the transport-based resistance to crystallization in the overall glass formation process. Our results show that the experimentally observed glass forming compositions for Al-(Ce,Gd,Ho,Nd,Y,Dy) alloys strongly correlate with the composition range bounded by the T0 curves associated with the relevant crystalline phases. This agreement indicates that sluggish material transport is a key factor governing glass formation in these systems, a behavior that differs substantially from the more common oxide glasses, where directional bonding constraints may stabilize the glassy network based on topological considerations. A jellium-passivated cluster model is developed to study the energetics of short-range ordering in supercooled liquid and glass systems. Calculations for single atoms embedded in jellium yield results in good agreement with bulk values for the cohesive energy, atomic volume as well as angular-momentum-projected electronic density of states. The energy difference between icosahedral clusters and FCC embryos in jellium is found to correlate with the glass-forming ability of liquid Al alloys. The model will be useful for studying the short-range order tendency with minor chemical additions in metallic glass formation, without the use of large unit cell calculations. We demonstrate an efficient and accurate first-principles method to calculate the electronic structure of a large system using a divide-and-conquer strategy based on localized quasi-atomic minimal basis set orbitals recently developed. Tight-binding Hamiltonian and overlap matrices of a big system can be constructed by extracting the matrix elements for a given pair of atoms from first-principles calculations of smaller systems that represent the local bonding environment of the particular atom pair. The approach is successfully applied to the studies of electronic structure in graphene nano-ribbons. This provides a promising way to do the electronic simulation for big systems directly from first-principles. We have developed a new density functional theory incorporating the correlated electronic effects into the kinetic energy via Gutzwiller approximation. All the Coulomb integrals are determined self-consistently without any adjustable parameters. In addition to the set of one-electron Schrödinger equations analogous to the standard LDA approach, we get another set of linear equations with respect to the probabilities of local configurations as the solution of the many body problem. A preliminary Fortran90 code has been developed with an interface to VASP. We applied our method to several systems with important electron correlation effects and got encouraging results.

Download or read book Forcefields for Atomistic Scale Simulations Materials and Applications written by Akarsh Verma and published by Springer Nature. This book was released on 2022-08-19 with total page 395 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes the forcefields/interatomic potentials that are used in the atomistic-scale and molecular dynamics simulations. It covers mechanisms, salient features, formulations, important aspects and case studies of various forcefields utilized for characterizing various materials (such as nuclear materials and nanomaterials) and applications. This book gives many help to students and researchers who are studying the forcefield potentials and introduces various applications of atomistic-scale simulations to professors who are researching molecular dynamics.

Download or read book Experimental and Computational Investigations of Structure and Plastic Flow in Bulk Metallic Glasses written by Matthew James Lambert and published by . This book was released on 2005 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Thermo-mechanical processing of metallic glasses has been shown to change the free volume and have some effect on the mechanical properties. In order to better quantify these effects, we have studied the homogeneous flow of metallic glasses and the subsequent changes in atomic ordering, in terms of free volume and x-ray measurements, and mechanical properties via nanoindentation. The internal free volume of the specimens, as measured through changes in the specific heat by differential scanning calorimetry, has been shown to increase with increasing levels of total strain in tension and in compression. X-ray diffraction of amorphous specimens in the as-cast, annealed, and homogeneously deformed state also showed a change in the short-range atomic order of the alloy. The shape of the x-ray patterns for the as-cast and annealed states were nearly identical, while a decrease in intensity of x-rays was seen at high angles of 2[theta] in the homogeneously deformed samples. These high angles describe a change in the state of the short-range order. Nanoindentation has shown slight changes in the elastic properties and density of serrations in amorphous materials with changes in the free volume. Using available embedded atom method potentials, molecular dynamics simulations of several Cu-Zr binary, a Cu-Zr-Al ternary, and a quinternary Zr-Cu-Ni-Al-Ti alloy systems at multiple quench rates from the liquid were performed. Using an annealing/quenching technique that allows the simulation of even extremely slow quench rates, glassy structures of these alloys were produced at varying quench rates and their nearest-neighbor coordination examined. Radial distribution functions of the modeled systems show excellent agreement with experimental data, suggesting that the predicted atomic structure should have realistic features similar to real materials. The glass transition temperatures of several of these alloys were determined through a simulated dilatometry technique. Comparing the features and changes in the nearest-neighbor order and the simulated glass transitions with available experimental data, we found a novel set of criteria to predict the effect of changes in alloy composition on glass forming ability. The change in the distribution of nearest neighbors with quench rate, as compared in alloys with different experimentally determined glass forming abilities, did only provide some insights into the formation of glasses. However, the measurement of the fraction of atomic pairs that exhibited icosahedral-like short-range order was found to be directly related to the relative glass forming abilities of the alloys simulated.

Download or read book Modeling the Amorphous Formability of Bulk Metallic Glasses written by Justin Cheney and published by . This book was released on 2004 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Glass Stability and Kinetic Analysis of Iron metalloid Bulk Metallic Glass written by and published by . This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Multicomponent Fe-based bulk metallic glasses (BMGs) with a combination of excellent properties such as good soft magnetic properties, high strength, high hardness, and high corrosion resistance have attracted increasing attention both from a basic science research standpoint and due to their industrial application potential. However, many of the elemental additions which lead to the easiest glass formation are expensive. The identification of alloys composed of abundant and inexpensive elements that still retain excellent properties would promote applications for engineering and industry. In short, the development of the Fe-based BMG without any glass-forming metal elements and with high glass forming ability is desired. This study shows that the thermal stability of the Fe-based alloys can be improved beyond a simple rule of mixtures prediction by utilizing a well-balance multi-metalloid approach. The kinetics aspect of glass-forming ability is studied experimentally for Fe-B-Si-P alloys. The systematic variation in alloy composition gives access to differences in phase selection and the final dimensions of glass formation. Two alloys, representing the best glass-forming composition and the poorest glass-forming composition, were studied in terms of their stability to crystallization, solidification microstructure evolution and thermal history. The utility of the wedge-casting technique is developed to examine bulk glass-forming alloys by combining multiple temperature profiles of the quenching melt with a measurement-based kinetic analysis of the phase selection competition and critical cooling rate conditions. Based upon direct thermal measurement, microstructural analysis and kinetic modeling, it was found that both representative alloys show a board spectrum of solidification microstructures which include a critical cooling rate range. The kinetic competition in the formation of certain phases can enhance or detract from the final dimension of bulk glass formation of the representative alloys. Practical strategies in crystallization kinetics analysis and microstructure control are developed to extend the knowledge of phase competition leading to successful synthesis of BMGs. Low cost Fe-metalloid BMGs will provide a great advantage for the transition to commercial applications when material cost is a critical issue.

Download or read book Net Shape Manufacturing of Bulk Metallic Glass and Prediction of Glass Forming Ability written by Li Yuelu and published by . This book was released on 2007 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Glass Forming Ability Crystallization and Properties of Pd based Bulk Metallic Glasses written by Hu Xiang and published by . This book was released on 2002 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Atomistic Simulations of Glasses written by Jincheng Du and published by John Wiley & Sons. This book was released on 2022-03-29 with total page 564 pages. Available in PDF, EPUB and Kindle. Book excerpt: A complete reference to computer simulations of inorganic glass materials In Atomistic Simulations of Glasses: Fundamentals and Applications, a team of distinguished researchers and active practitioners delivers a comprehensive review of the fundamentals and practical applications of atomistic simulations of inorganic glasses. The book offers concise discussions of classical, first principles, Monte Carlo, and other simulation methods, together with structural analysis techniques and property calculation methods for the models of glass generated from these atomistic simulations, before moving on to practical examples of the application of atomistic simulations in the research of several glass systems. The authors describe simulations of silica, silicate, aluminosilicate, borosilicate, phosphate, halide and oxyhalide glasses with up-to-date information and explore the challenges faced by researchers when dealing with these systems. Both classical and ab initio methods are examined and comparison with experimental structural and property data provided. Simulations of glass surfaces and surface-water reactions are also covered. Atomistic Simulations of Glasses includes multiple case studies and addresses a variety of applications of simulation, from elucidating the structure and properties of glasses for optical, electronic, architecture applications to high technology fields such as flat panel displays, nuclear waste disposal, and biomedicine. The book also includes: A thorough introduction to the fundamentals of atomistic simulations, including classical, ab initio, Reverse Monte Carlo simulation and topological constraint theory methods Important ingredients for simulations such as interatomic potential development, structural analysis methods, and property calculations are covered Comprehensive explorations of the applications of atomistic simulations in glass research, including the history of atomistic simulations of glasses Practical discussions of rare earth and transition metal-containing glasses, as well as halide and oxyhalide glasses In-depth examinations of glass surfaces and silicate glass-water interactions Perfect for glass, ceramic, and materials scientists and engineers, as well as physical, inorganic, and computational chemists, Atomistic Simulations of Glasses: Fundamentals and Applications is also an ideal resource for condensed matter and solid-state physicists, mechanical and civil engineers, and those working with bioactive glasses. Graduate students, postdocs, senior undergraduate students, and others who intend to enter the field of simulations of glasses would also find the book highly valuable.