Structural Study of Supercooled Liquids and Metallic Glasses by High-energy X-ray Diffraction and Reverse Monte Carlo Simulation
Title | Structural Study of Supercooled Liquids and Metallic Glasses by High-energy X-ray Diffraction and Reverse Monte Carlo Simulation PDF eBook |
Author | Tae Ho Kim |
Publisher | |
Pages | 347 |
Release | 2007 |
Genre | |
ISBN | 9780549070207 |
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.
Supercooled Liquids, Glass Transition and Bulk Metallic Glasses: Volume 754
Title | Supercooled Liquids, Glass Transition and Bulk Metallic Glasses: Volume 754 PDF eBook |
Author | Takeshi Egami |
Publisher | |
Pages | 512 |
Release | 2003-07-16 |
Genre | Science |
ISBN |
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.
Study of Mechanical Behaviors and Structures of Bulk Metallic Glasses with High-energy Synchrotron X-ray Diffraction
Title | Study of Mechanical Behaviors and Structures of Bulk Metallic Glasses with High-energy Synchrotron X-ray Diffraction PDF eBook |
Author | Feng Jiang |
Publisher | |
Pages | 192 |
Release | 2011 |
Genre | |
ISBN |
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.
X-Ray Absorption and X-Ray Emission Spectroscopy
Title | X-Ray Absorption and X-Ray Emission Spectroscopy PDF eBook |
Author | Jeroen A. van Bokhoven |
Publisher | John Wiley & Sons |
Pages | 896 |
Release | 2016-01-08 |
Genre | Science |
ISBN | 1118844262 |
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
Structural, Electronic, and Dynamic Properties of Metallic Supercooled Liquid and Glasses Studied by NMR.
Title | Structural, Electronic, and Dynamic Properties of Metallic Supercooled Liquid and Glasses Studied by NMR. PDF eBook |
Author | |
Publisher | |
Pages | 7 |
Release | 2003 |
Genre | |
ISBN |
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.
Structural Glasses and Supercooled Liquids
Title | Structural Glasses and Supercooled Liquids PDF eBook |
Author | Peter G. Wolynes |
Publisher | John Wiley & Sons |
Pages | 422 |
Release | 2012-04-10 |
Genre | Science |
ISBN | 0470452234 |
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.
Proceedings of PP1594: Topological Engineering of Ultrastrong Glasses
Title | Proceedings of PP1594: Topological Engineering of Ultrastrong Glasses PDF eBook |
Author | Lothar Wondraczek |
Publisher | Frontiers Media SA |
Pages | 169 |
Release | 2021-02-25 |
Genre | Technology & Engineering |
ISBN | 2889665127 |