Download or read book Structural Study of Supercooled Liquids and Metallic Glasses by High energy X ray Diffraction and Reverse Monte Carlo Simulation written by Tae Ho Kim and published by . This book was released on 2007 with total page 347 pages. Available in PDF, EPUB and Kindle. Book excerpt: The local structures of Ti-Zr-Ni liquids that form quasicrystal phases and TiFeSiO liquids that form crystal approximant phases were studied as a function of supercooling. This study found similarities between the supercooled liquid and quasicrystal structures in Ti-Zr-Ni and the liquid and approximant structures in TiFeSiO.
Download or read book Supercooled Liquids Glass Transition and Bulk Metallic Glasses Volume 754 written by Takeshi Egami and published by . This book was released on 2003-07-16 with total page 512 pages. Available in PDF, EPUB and Kindle. Book excerpt: There has been a renaissance in glass science brought about by the development of concepts such as fragility index and the energy landscape with megabasins. Research on bulk metallic glasses has been explosive since their advent when MRS offered its first book on the topic. In 2000, a second book broadened the scope to include supercooled liquid, bulk glassy and nanocrystalline states. This book enhances the scope to include glass transition in diverse materials such as water, silicate and polymeric melts. Bringing these threads together in an interdisciplinary manner was fruitful and offers proof that while there is much common ground, gaps between various approaches to the glassy state remain to be bridged. Subjects include: the supercooled liquid; glass formability; structural relaxation and dynamics; structure determination and modeling; processing and applications of bulk metallic glasses; mechanical properties; mechanical properties - composites; crystallization; electronic and magnetic structure and properties; and nanoparticles and nonmetallic glasses.
Download or read book Study of Mechanical Behaviors and Structures of Bulk Metallic Glasses with High energy Synchrotron X ray Diffraction written by Feng Jiang and published by . This book was released on 2011 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation addresses two critical issues in the mechanical behaviors and structures of bulk-metallic glasses (BMGs): (1) the effect of composition, fabrication method, and pretreatment of plastic deformation on mechanical properties and structures of BMGs; (2) the mechanical response and structural evolution of BMGs in the elastic and plastic region. (Cu50Zr50)94Al6 and (Cu50Zr50)92Al amorphous alloys were used to study the effect of composition on mechanical properties and structures of BMGs. The (Cu50Zr50)94Al6 alloy exhibits lower yield stress and Young's modulus, higher Poisson's ratio, worse thermal stability, and better plasticity than (Cu50Zr50)92Al. Both the topological and chemical effects of Al addition account for the differences of mechanical and physical properties between them. A Zr55Ni5Al10Cu30 glass-forming alloy with injection casting (the melting temperatures are 1,550 K and 1,250 K, respectively) and with suction casting was fabricated. The results indicate that despite their amorphous structures, the suction-casting samples exhibit a lower yield stress, lower Young's modulus, and larger plastic strain than the injection-casting samples (the melting temperature is 1,550 K) due to more quenched-in free volumes in suction casting, which results from the higher cooling rate. The inhomogeneous plastic deformation in Zr50Cu40Al10 BMG samples was introduced by four-point-bend fatigue. There is almost no difference of the stress-strain behaviors between the deformed and undeformed samples. Elastostatic compression was used to introduce homogeneous deformation in Zr--0Cu6Ni16Al8 BMG samples. The preloaded samples are softer with decreases of yield strength and Young's moduli. Anisotropy was observed in the preloaded samples despite their small magnitudes, which even occurred at a relatively low temperature and applied stress level. The structural evolution of Zr--0Cu6Ni16Al8 BMG in the elastic region was analyzed with anisotropic pair density function. The analysis of the first shell of Zr--0Cu6Ni16Al8 glass confirms the structural changes in the elastic region. The bond reorientation leads to direction dependent changes in the chemical short-range order. The structural evolution in the plastic region of Zr--0Cu6Ni16Al8 BMG is investigated as well. The serrations were observed for both the stress-displacement and full width at half maximum-displacement curves. The excess free volume was measured, which increases with increasing the displacement.
Download or read book X Ray Absorption and X Ray Emission Spectroscopy written by Jeroen A. van Bokhoven and published by John Wiley & Sons. This book was released on 2016-01-08 with total page 896 pages. Available in PDF, EPUB and Kindle. Book excerpt: During the last two decades, remarkable and often spectacular progress has been made in the methodological and instrumental aspects of x–ray absorption and emission spectroscopy. This progress includes considerable technological improvements in the design and production of detectors especially with the development and expansion of large-scale synchrotron reactors All this has resulted in improved analytical performance and new applications, as well as in the perspective of a dramatic enhancement in the potential of x–ray based analysis techniques for the near future. This comprehensive two-volume treatise features articles that explain the phenomena and describe examples of X–ray absorption and emission applications in several fields, including chemistry, biochemistry, catalysis, amorphous and liquid systems, synchrotron radiation, and surface phenomena. Contributors explain the underlying theory, how to set up X–ray absorption experiments, and how to analyze the details of the resulting spectra. X-Ray Absorption and X-ray Emission Spectroscopy: Theory and Applications: Combines the theory, instrumentation and applications of x-ray absorption and emission spectroscopies which offer unique diagnostics to study almost any object in the Universe. Is the go-to reference book in the subject for all researchers across multi-disciplines since intense beams from modern sources have revolutionized x-ray science in recent years Is relevant to students, postdocurates and researchers working on x-rays and related synchrotron sources and applications in materials, physics, medicine, environment/geology, and biomedical materials
Download or read book Structural Electronic and Dynamic Properties of Metallic Supercooled Liquid and Glasses Studied by NMR written by and published by . This book was released on 2003 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metallic glasses possess unique mechanical and magnetic properties such as extremely high hardness and have novel applications in many areas including national defense. What prevents the widespread use of metallic glasses is the difficulty in achieving the glassy form due to the low glass forming ability (GFA) of most metallic alloys. The search of new BMCs requires an understanding of GFA on the atomic level and over a wide range of timescales. In this study we used nuclear magnetic resonance (NMR), along with other techniques, to study both structures and atomic motions in Zr-based and Pd-based BMO systems over the entire temperature range from the liquid state down to the glassy state. We observed a clear evidence of a dynamic crossover at temperature Tc above the glass transition temperature Tg. This observation shows that below Tc atomic raffling within cages formed by neighboring atoms freezes rapidly. It demonstrates that such dynamic crossover plays a crucial role in glass transition. Comprehensive studies using NMR, x-ray diffraction, and differential scanning calorimetry revealed the details of nucleation and growth processes in such BMGs and 14.
Download or read book Structural Glasses and Supercooled Liquids written by Peter G. Wolynes and published by John Wiley & Sons. This book was released on 2012-04-10 with total page 422 pages. Available in PDF, EPUB and Kindle. Book excerpt: With contributions from 24 global experts in diverse fields, and edited by world-recognized leaders in physical chemistry, chemical physics and biophysics, Structural Glasses and Supercooled Liquids: Theory, Experiment, and Applications presents a modern, complete survey of glassy phenomena in many systems based on firmly established characteristics of the underlying molecular motions as deduced by first principle theoretical calculations, or with direct/single-molecule experimental techniques. A well-rounded view of a variety of disordered systems where cooperative phenomena, which are epitomized by supercooled liquids, take place is provided. These systems include structural glasses and supercooled liquids, polymers, complex liquids, protein conformational dynamics, and strongly interacting electron systems with quenched/self-generated disorder. Detailed calculations and reasoned arguments closely corresponding with experimental data are included, making the book accessible to an educated non-expert reader.
Download or read book Proceedings of PP1594 Topological Engineering of Ultrastrong Glasses written by Lothar Wondraczek and published by Frontiers Media SA. This book was released on 2021-02-25 with total page 169 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Molecular Dynamics Study of the Structure dynamics Relationships of Supercooled Liquids and Glasses written by Ryan Soklaski and published by . This book was released on 2015 with total page 115 pages. Available in PDF, EPUB and Kindle. Book excerpt: Central to the field of condensed matter physics is a decades old outstanding problem in the study of glasses -- namely explaining the extreme slowing of dynamics in a liquid as it is supercooled towards the so-called glass transition. Efforts to universally describe the stretched relaxation processes and heterogeneous dynamics that characteristically develop in supercooled liquids remain divided in both their approaches and successes. Towards this end, a consensus on the role that atomic and molecular structures play in the liquid is even more tenuous. However, mounting material science research efforts have culminated to reveal that the vast diversity of metallic glass species and their properties are rooted in an equally-broad set of structural archetypes. Herein lies the motivation of this dissertation: the detailed information available regarding the structure-property relationships of metallic glasses provides a new context in which one can study the evolution of a supercooled liquid by utilizing a structural motif that is known to dominate the glass. Cu_64 Zr_36 is a binary alloy whose good glass-forming ability and simple composition makes it a canonical material to both empirical and numerical studies. Here, we perform classical molecular dynamics simulations and conduct a comprehensive analysis of the dynamical regimes of liquid Cu_64 Zr_36, while focusing on the roles played by atomic icosahedral ordering -- a structural motif which ultimately percolates the glass' structure. Large data analysis techniques are leveraged to obtain uniquely detailed structural and dynamical information in this context. In doing so, we develop the first account of the origin of icosahedral order in this alloy, revealing deep connections between this incipient structural ordering, frustration-limited domain theory, and recent important empirical findings that are relevant to the nature of metallic liquids at large. Furthermore, important dynamical landmarks such as the breakdown of the Stokes-Einstein relationship, the decoupling of particle diffusivities, and the development of general "glassy" relaxation features are found to coincide with successive manifestation of icosahedral ordering that arise as the liquid is supercooled. Remarkably, we detect critical-like features in the growth of the icosahedron network, with signatures that suggest that a liquid-liquid phase transition may occur in the deeply supercooled regime to precede glass formation. Such a transition is predicted to occur in many supercooled liquids, although explicit evidence of this phenomenon in realistic systems is scarce. Ultimately this work concludes that icosahedral order characterizes all dynamical regimes of Cu_64 Zr_36, demonstrating the importance and utility of studying supercooled liquids in the context of locally-preferred structure. More broadly, it serves to confirm and inform recent theoretical and empirical findings that are central to understanding the physics underlying the glass transition.
Download or read book Structural Rejuvenation in Bulk Metallic Glasses written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Using high-energy X-ray diffraction we study structural changes in bulk metallic glasses after uniaxial compressive homogeneous deformation at temperatures slightly below the glass transition. We observe that deformation results in structural disordering corresponding to an increase in the fictive, or effective, temperature. However, the structural disordering saturates after yielding. Lastly, examination of the experimental structure and molecular dynamics simulation suggests that local changes in the atomic connectivity network are the main driving force of the structural rejuvenation.
Download or read book Metals Abstracts written by and published by . This book was released on 1994 with total page 1584 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Structural Study of Metallic Glasses Using Variable Two theta and Variable Energy X ray Diffraction Techniques written by Dokyol Lee and published by . This book was released on 1980 with total page 490 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Molecular Dynamics Simulation of Nanostructured Materials written by Snehanshu Pal and published by CRC Press. This book was released on 2020-04-28 with total page 334 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 Structural Aspects of Deformation in Bulk Metallic Glasses written by Yang Tong and published by . This book was released on 2015 with total page 119 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metallic glasses have liquid-like structure without well-defined topological defects like dislocations in metals and alloys. The unique disordered structure of metallic glasses leads to unique mechanical properties, such as inhomogeneous deformation at low temperature and homogeneous deformation at high temperature, and brittle behavior induced by annealing. This dissertation address three critical issues related to the mechanical behavior of metallic glasses: 1. Identification of deformation defects in metallic glasses. We have conducted high energy X-ray diffraction experiment -- using anisotropic pair distribution function -- to characterize the size and density of defects in metallic glasses activated by external stresses. Our results based on the characterization method reveal the microscopic origin of ductility in some metallic glasses. 2. Identification of two local stress relaxation modes that control macroscopic mechanical properties in metallic glasses. Using the defect characterization method we developed, we revealed two different local stress relaxation modes in defect regions, which are responsible for inhomogeneous and homogeneous deformation respectively. 3. We developed structural rejuvenation method to improve and recover the compressive plasticity. The microscopic mechanism of structural rejuvenation was unveiled by structural study and molecular dynamics simulation.
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 543 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 PRICM 6 written by Young Won Chang and published by . This book was released on 2007 with total page 864 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Structural Chemistry of Glasses written by K.J. Rao and published by Elsevier. This book was released on 2002-06-26 with total page 585 pages. Available in PDF, EPUB and Kindle. Book excerpt: Structural Chemistry of Glasses provides detailed coverage of the subject for students and professionals involved in the physical chemistry aspects of glass research. Starting with the historical background and importance of glasses, it follows on with methods of preparation, structural and bonding theories, and criteria for glass formation including new approaches such as the constraint model. Glass transition is considered, as well as the wide range of theoretical approaches that are used to understand this phenomenon. The author provides a detailed discussion of Boson peaks, FSDP, Polymorphism, fragility, structural techniques, and theoretical modelling methods such as Monte Carlo and Molecular Dynamics simulation. The book covers ion and electron transport in glasses, mixed-alkali effect, fast ion conduction, power law and scaling behaviour, electron localization, charged defects, photo-structural effects, elastic properties, pressure-induced transitions, switching behaviour, colour, and optical properties of glasses. Special features of a variety of oxide, chalcogenide, halide, oxy-nitride and metallic gasses are discussed. With over 140 sections, this book captures most of the important and topical aspects of glass science, and will be useful for both newcomers to the subject and the experienced practitioner.
Download or read book Structural Studies on Some Metallic Glasses Using X ray and Neutron Diffraction Methods written by Saleh H. Al-Heniti and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
