Download or read book Relationship Between Nanocrystalline and Amorphous Microstructures by Molecular Dynamics Simulation written by and published by . This book was released on 1996 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: A recent molecular dynamics simulation method for growth of fully dense nanocrystalline materials crystallized from melt was used with the Stillinger-Weber three-body potential to synthesize nanocrystalline Si with a grain size up to 75Å. Structures of the highly constrained grain boundaries (GBs), triple lines, and point grain junctions were found to be highly disordered and similar to the structure of amorphous Si. These and earlier results for fcc metals suggest that a nanocrystalline microstructure may be viewed as a two-phase system, namely an ordered crystalline phase in the grain interiors connected by an amorphous, intergranular, glue-like phase. Analysis of the structures of bicrystalline GBs in the same materials reveals the presence of an amorphous intergranular equilibrium phase only in the high-energy but not the low-energy GBs, suggesting that only high-energy boundaries are present in nanocrystalline microstructures.

Download or read book Shear Deformation of Amorphous and Nanocrystalline Copper Microstructures Via Atomistic Simulation written by David R. Gandy and published by . This book was released on 2007 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the well-known Hall-Petch behavior, yield and flow stresses in polycrystalline metals increase with a decrease in grain size. As grain size continues to decrease, mechanical strength peaks. As grain size further decreases, mechanical strength begins to decrease. As grain size approaches zero, the total structure is composed of an increasingly high percentage of grain boundaries, which exhibit the properties of an amorphous structure. Molecular dynamics simulations, with the goal of exploring this behavior, were performed on nanocrystalline and amorphous microstructures using the embedded atom potential developed by Mishin et al. A 0.2 shear strain was applied to each of the nanocrystalline and amorphous samples. From these simulations, we have observed the inverse Hall-Petch behavior of nanocrystalline structures. We have also shown that the amorphous structure as zero grain size is reasonable as the limiting case for the inverse Hall-Petch trends in nanocrystalline structures.

Download or read book The Structure property Relation in Nanocrystalline Materials written by Tao Xu and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanocrystalline materials have been under extensive study in the past two decades. The reduction in grain size induces many abnormal behaviors in the properties of nanocrystalline materials, that have been investigated systematically and quantitatively. As one of the most fundamental relations in materials science, the structure-property relation should still apply on materials of nano-scale grain sizes. The characterization of grain boundaries (GBs) and related entities remains a big obstacle to understanding the structure-property relation in nanocrystalline materials. It is challenging experimentally to determine the topological properties of polycrystalline materials due to the complex and disordered grain boundary network presented in the nanocrystalline materials. The constantly improving computing power enables us to study the structure-property relation in nanocrystalline materials via Monte Carlo and molecular dynamic simulations. : In this study, we will first propose a geometrical construction method based on inverse Monte Carlo simulation to generate digital microstructures with desired topological properties such as grain size, interface area, triple junction length as well as their statistical distributions. The influences on the grain shapes by different topological properties are studied. Two empirical geometrical laws are examined including the Lewis rule and Aboav-Weaire law. Secondly, defect free nanocrystalline Copper (nc-Cu) samples are generated by filling atoms into the Voronoi structure and then relaxed by molecular dynamics simulations. Atoms in the relaxed nc-Cu samples are then characterized into grain atoms, GB interface atoms, GB triple junction atoms and vertex atoms using a newly proposed method. Atoms in each GB entity can also be identified. Next, the topological properties of nc-Cu samples before and after relaxation are calculated and compared, indicating that there exists a physical limit in the number of atoms to form a stable grain boundary interface and triple junction in nanocrystalline materials. In addition, we are able to obtain the statistical averages of geometrical and thermal properties of atoms across each GB interfaces, the so-called GB profiles, and study the grain size, misorientation and temperature effects on the microstructures in nanocrystalline materials. Finally, nc-Cu samples with different topological properties are deformed under simple shear using MD simulation in an attempt to study the structure-property relation in nanocrystalline materials.

Download or read book Metallic Glass Based Nanocomposites written by Sumit Sharma and published by CRC Press. This book was released on 2019-09-23 with total page 167 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metallic Glass-Based Nanocomposites: Molecular Dynamics Study of Properties provides readers with an overview of the most commonly used tools for MD simulation of metallic glass composites and provides all the basic steps necessary for simulating any material on Materials Studio. After reading this book, readers will be able to model their own problems on this tool for predicting the properties of metallic glass composites. This book provides an introduction to metallic glasses with definitions and classifications, provides detailed explanations of various types of composites, reinforcements and matrices, and explores the basic mechanisms of reinforcement-MG interaction during mechanical loading. It explains various models for calculating the thermal conductivity of metallic glass composites and provides examples of molecular dynamics simulations. Aimed at students and researchers, this book caters to the needs of those working in the field of molecular dynamics (MD) simulation of metallic glass composites.

Download or read book Nanostructured Films and Coatings written by Gan-Moog Chow and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 379 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanostructured films and coatings possess unique properties due to both size and interface effects. They find many applications in areas such as electronics, catalysis, protection, data storage, optics and sensors. The focus of the present book is on synthesis and processing; advanced characterization techniques; properties (including mechanical, chemical, electronic, thermal, catalytic, and magnetic); modelling of interlayer and intralayer interfaces; and applications.

Download or read book Molecular Dynamics Simulation of Nanostructured Materials written by Snehanshu Pal and published by CRC Press. This book was released on 2020-05-15 with total page 305 pages. Available in PDF, EPUB and Kindle. Book excerpt: Molecular dynamics simulation is a significant technique to gain insight into the mechanical behavior of nanostructured (NS) materials and associated underlying deformation mechanisms at the atomic scale. The purpose of this book is to detect and correlate critically current achievements and properly assess the state of the art in the mechanical behavior study of NS material in the perspective of the atomic scale simulation of the deformation process. More precisely, the book aims to provide representative examples of mechanical behavior studies carried out using molecular dynamics simulations, which provide contributory research findings toward progress in the field of NS material technology.

Download or read book Advanced Tribology written by Jianbin Luo and published by Springer Science & Business Media. This book was released on 2010-07-16 with total page 1040 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Advanced Tribology" is the proceedings of the 5th China International Symposium on Tribology (held every four years) and the 1st International Tribology Symposium of IFToMM, held in Beijing 24th-27th September 2008. It contains seven parts: lubrication; friction and wear; micro/nano-tribology; tribology of coatings, surface and interface; biotribology; tribo-chemistry; industry tribology. The book reflects the recent progress in the fields such as lubrication, friction and wear, coatings, and precision manufacture etc. in the world. The book is intended for researchers, engineers and graduate students in the field of tribology, lubrication, mechanical production and industrial design. The editors Jianbin Luo, Yonggang Meng, Tianmin Shao and Qian Zhao are all the professors at the State Key Lab of Tribology, Tsinghua University, Beijing.

Download or read book Molecular Dynamics Simulations of Disordered Materials written by Carlo Massobrio and published by Springer. This book was released on 2015-04-22 with total page 540 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a unique reference work in the area of atomic-scale simulation of glasses. For the first time, a highly selected panel of about 20 researchers provides, in a single book, their views, methodologies and applications on the use of molecular dynamics as a tool to describe glassy materials. The book covers a wide range of systems covering "traditional" network glasses, such as chalcogenides and oxides, as well as glasses for applications in the area of phase change materials. The novelty of this work is the interplay between molecular dynamics methods (both at the classical and first-principles level) and the structure of materials for which, quite often, direct experimental structural information is rather scarce or absent. The book features specific examples of how quite subtle features of the structure of glasses can be unraveled by relying on the predictive power of molecular dynamics, used in connection with a realistic description of forces.

Download or read book Plasticity and Failure in Nanocrystalline BCC Metals Via Molecular Dynamics Simulation written by and published by . This book was released on 2010 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in the ability to generate extremely high pressures in dynamic experiments such as at the National Ignition Facility has motivated the need for special materials optimized for those conditions as well as ways to probe the response of these materials as they are deformed. We need to develop a much deeper understanding of the behavior of materials subjected to high pressure, especially the effect of rate at the extremely high rates encountered in those experiments. Here we use large-scale molecular dynamics (MD) simulations of the high-rate deformation of nanocrystalline tantalum at pressures less than 100 GPa to investigate the processes associated with plastic deformation for strains up to 100%. We focus on 3D polycrystalline systems with typical grain sizes of 10-20 nm. We also study a rapidly quenched liquid (amorphous solid) tantalum. We apply a constant volume (isochoric), constant temperature (isothermal) shear deformation over a range of strain rates, and compute the resulting stress-strain curves to large strains for both uniaxial and biaxial compression. We study the rate dependence and identify plastic deformation mechanisms. The identification of the mechanisms is facilitated through a novel technique that computes the local grain orientation, returning it as a quaternion for each atom. This analysis technique is robust and fast, and has been used to compute the orientations on the fly during our parallel MD simulations on supercomputers. We find both dislocation and twinning processes are important, and they interact in the weak strain hardening in these extremely fine-grained microstructures. We also present some results on void growth in nanocrystalline BCC metals under tension.

Download or read book Silicon Carbide written by Moumita Mukherjee and published by BoD – Books on Demand. This book was released on 2011-10-10 with total page 562 pages. Available in PDF, EPUB and Kindle. Book excerpt: Silicon Carbide (SiC) and its polytypes, used primarily for grinding and high temperature ceramics, have been a part of human civilization for a long time. The inherent ability of SiC devices to operate with higher efficiency and lower environmental footprint than silicon-based devices at high temperatures and under high voltages pushes SiC on the verge of becoming the material of choice for high power electronics and optoelectronics. What is more important, SiC is emerging to become a template for graphene fabrication, and a material for the next generation of sub-32nm semiconductor devices. It is thus increasingly clear that SiC electronic systems will dominate the new energy and transport technologies of the 21st century. In 21 chapters of the book, special emphasis has been placed on the materials aspects and developments thereof. To that end, about 70% of the book addresses the theory, crystal growth, defects, surface and interface properties, characterization, and processing issues pertaining to SiC. The remaining 30% of the book covers the electronic device aspects of this material. Overall, this book will be valuable as a reference for SiC researchers for a few years to come. This book prestigiously covers our current understanding of SiC as a semiconductor material in electronics. The primary target for the book includes students, researchers, material and chemical engineers, semiconductor manufacturers and professionals who are interested in silicon carbide and its continuing progression.

Download or read book Mechanical Behavior of Advanced Materials Modeling and Simulation written by Qihong Fang and published by CRC Press. This book was released on 2023-11-30 with total page 339 pages. Available in PDF, EPUB and Kindle. Book excerpt: With the recent developments in the field of advanced materials, there exists a need for a systematic summary and detailed introduction of the modeling and simulation methods for these materials. This book provides a comprehensive description of the mechanical behavior of advanced materials using modeling and simulation. It includes materials such as high-entropy alloys, high-entropy amorphous alloys, nickel-based superalloys, light alloys, electrode materials, and nanostructured reinforced composites. Reviews the performance and application of a variety of advanced materials and provides the detailed theoretical modeling and simulation of mechanical properties Covers the topics of deformation, fracture, diffusion, and fatigue Features worked examples and exercises that help readers test their understanding This book is aimed at researchers and advanced students in solid mechanics, material science, engineering, material chemistry, and those studying the mechanics of materials.

Download or read book Developments in Strategic Ceramic Materials written by Waltraud M. Kriven and published by John Wiley & Sons. This book was released on 2016-01-05 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Ceramic Engineering and Science Proceeding has been published by The American Ceramic Society since 1980. This series contains a collection of papers dealing with issues in both traditional ceramics (i.e., glass, whitewares, refractories, and porcelain enamel) and advanced ceramics. Topics covered in the area of advanced ceramic include bioceramics, nanomaterials, composites, solid oxide fuel cells, mechanical properties and structural design, advanced ceramic coatings, ceramic armor, porous ceramics, and more.

Download or read book Recent Advancements in Metallic Glasses written by Vitaly A. Khonik and published by MDPI. This book was released on 2021-06-09 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Special Issue “Recent Advancements in Metallic Glasses” presents ten original papers, considering both scientific and application issues related to metallic glasses. The papers are devoted to general consideration of the formation and defects of the glassy structure, defect evolution due to heat treatment, deformation behavior upon compression and high-pressure torsion, amorphous-crystalline transformation, hydrogenation behavior, and biomedical applications.

Download or read book Ultrananocrystalline Diamond written by Olga A. Shenderova and published by William Andrew. This book was released on 2006-08-10 with total page 621 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ultrananocrystalline Diamond: Syntheses, Properties, and Applications is a unique practical reference handbook that brings together the basic science of nanoscale carbon structures, particularly its diamond phase, with detailed information on nanodiamond synthesis, properties, and applications. Here you will learn about UNCD in its two forms, as a dispersed powder made by detonation techniques and as a chemical vapor deposited film. You will also learn about the superior mechanical, tribological, transport, electrochemical, and electron emission properties of UNCD for a wide range of applications including MEMS, NEMS, surface acoustic wave (SAW) devices, electrochemical sensors, coatings for field emission arrays, photonic and RF switching, biosensors, and neural prostheses, and more. This ôEverything about Ultra-nanocrystalline Diamondö book with 16 chapters is written by leading experts worldwide. It is for everyone who researches carbon nanostructures, everyone who produces them, everyone who characterizes them, and everyone who builds devices using them.

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 702 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Molecular Dynamics for Amorphous Materials written by Carlo Massobrio and published by IOP ebooks. This book was released on 2023-01-31 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This reference text demonstrates how molecular dynamics can be used in practice to achieve a precise understanding of structural properties for systems devoid of any order beyond the first interatomic distances. The reader will learn the basic principles underlying molecular dynamics with a special emphasis on first-principles methodology. A roadmap of correct and efficient use is also provided using clear examples. The book concludes with a set of results that exemplify the level of accuracy and information inherent in (first-principles) molecular dynamics methodology when applied to amorphous and glassy materials. While the majority of systems studied are disordered chalcogenides, the ideas, concepts and methodologies involved are easily applicable to any system, providing a universal manual well-adapted to a wide range of practitioners, from graduate students to experienced researchers. Key Features: Describes the structure of amorphous materials using molecular dynamics through research conducted by a single author over an extended period of time Demonstrates how molecular dynamics can be used in practice to achieve a precise understanding of structural properties for systems devoid of any order beyond the first interatomic distances Provides a roadmap of correct and efficient use using clear examples Includes a set of results that exemplify the level of accuracy and information inherent in (first-principles) molecular dynamics methodology when applied to amorphous and glassy materials Covers ideas, concepts and methodologies that are easily applicable to any system Provides a universal manual well-adapted to a wide range of practitioners, from graduate students to experienced researchers

Download or read book Science in China written by and published by . This book was released on 2006 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt: