Download or read book The Microstructural Evolution and Mechanical Behavior of Materials in the Extreme Environments of High velocity Impact and Irradiation written by Claire E. Griesbach and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding the process-structure-property relations is imperative when designing materials for critical applications, especially when exposed to extreme environments. Clever design of materials containing structural heterogeneities or features spanning multiple length scales can provide synergistically improved properties well beyond the limits of their homogeneous components or provide predictable and acceptable failure modes. In this work, we investigate the process-structure-property relations and the potential for improved performance of materials exposed to the extreme environments of high-velocity impact and irradiation.Similar to material processing techniques such as shot peening and cold spray which induce structural changes through high-velocity impact, we perform well-controlled single microprojectile impact tests of silver (Ag) single crystals which allows for clear correlation of the post-deformation microstructures to the impact-induced plasticity mechanisms. When comparing the impacted microsamples to their pristine single crystal counterparts, we find that the high-strain rates achieved during impact ([epsilon]~108 s-1) induce dramatic structural changes including extensive grain refinement, dislocation density gradients, and a martensitic phase transformation, while the quasi-statically ([epsilon]=10-2 s-1) compressed Ag microcubes remain single crystalline. The impacted samples show a synergistic improvement in strength and toughness, each on average over twice the respective properties of single crystal and bulk polycrystal Ag samples. Such synergistic improvements result from heterogeneous deformation induced stress and strain gradients. Progressive yielding of the gradient grain structure causes enhanced nucleation and pile-up of dislocations in the relatively softer domains to accommodate the elastic-plastic mismatch between grains. The observed dislocation accumulation-which is higher in larger grains-provides ultra-high strain hardening. Additionally, enhanced toughness is achieved through intergranular plasticity mechanisms such as nanograin rotation and grain boundary migration, leading to grain coalescence. These complementary inter- and intragranular plasticity mechanisms elicit improved mechanical properties. We demonstrate the ability to tune the dominant plasticity mechanisms-and thus the resultant properties-through control over the crystal orientation and impact velocity. Our findings provide new understandings of impact-induced nanostructural evolution and mechanistic pathways to improve mechanical properties through heterogeneous deformation, which can be used to improve high strain rate metal processing techniques. The second research thrust examines the effects of structural heterogeneity on the mechanical properties, performance, and failure of tristructural isotropic (TRISO) coated nuclear fuel particles. We examine the irradiation-induced densification and fracture behavior of the porous pyrocarbon buffer layer, which has pronounced effects on the overall particle's performance. Microstructural characterization of the initial as-fabricated buffer layer reveals a gradient of increasing porosity in the radial direction with the porosity reaching a maximum near the buffer-IPyC interface-which is commonly where circumferential tearing initiates in the buffer layer. Using the as-fabricated buffer structure as a basis to investigate the irradiation-induced structural changes, we study the influences of irradiation temperature and fluence on buffer layer response, by characterizing multiple TRISO particles from three different irradiation condition groups. The high temperatures, radiation damage, and mechanical stresses applied to the buffer layer during irradiation cause irradiation condition-dependent micro and nanostructural changes: localized densification near the kernel occurs in particles exposed to relatively lower temperatures, whereas significant changes in the entire pore microstructure occur in particles irradiated under high temperature and fluence. Intriguingly, a large proportion of the total buffer layer densification is accommodated through graphitization of the pyrocarbon rather than the changes in the pore microstructure. Significant nanostructural changes-including an increase in crystallite size, decrease in interplanar spacing, and formation of onion-like graphitic structures-contribute to densification and are most pronounced in the samples exposed to the highest temperature and fluence. Our findings provide a new detailed understanding of the irradiation-induced densification and fracture behavior of the pyrocarbon buffer layer in TRISO nuclear fuel particles, which will enable better predictions of buffer failure, aid in improved future designs, and provide guidance on the acceptable usage of these particles given different reactor conditions.

Download or read book Microstructural Evolution and Mechanical Response of Materials by Design and Modeling written by Aniket Kumar Dutt and published by . This book was released on 2017 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Materials Under Extreme Conditions written by A. K. Tyagi and published by Elsevier. This book was released on 2017-01-13 with total page 872 pages. Available in PDF, EPUB and Kindle. Book excerpt: Materials Under Extreme Conditions: Recent Trends and Future Prospects analyzes the chemical transformation and decomposition of materials exposed to extreme conditions, such as high temperature, high pressure, hostile chemical environments, high radiation fields, high vacuum, high magnetic and electric fields, wear and abrasion related to chemical bonding, special crystallographic features, and microstructures. The materials covered in this work encompass oxides, non-oxides, alloys and intermetallics, glasses, and carbon-based materials. The book is written for researchers in academia and industry, and technologists in chemical engineering, materials chemistry, chemistry, and condensed matter physics. - Describes and analyzes the chemical transformation and decomposition of a wide range of materials exposed to extreme conditions - Brings together information currently scattered across the Internet or incoherently dispersed amongst journals and proceedings - Presents chapters on phenomena, materials synthesis, and processing, characterization and properties, and applications - Written by established researchers in the field

Download or read book Mechanical Behavior of Materials written by Marc A. Meyers and published by . This book was released on 2008 with total page 856 pages. Available in PDF, EPUB and Kindle. Book excerpt: Includes numerous examples and problems for student practice, this textbook is ideal for courses on the mechanical behaviour of materials taught in departments of mechanical engineering and materials science.

Download or read book Materials in Extreme Environments Volume 929 written by Daryush Ila and published by . This book was released on 2006-09-15 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book investigates the fundamental properties and response of materials in extreme environments such as static and dynamic high pressure, high strain and high strain-rates, high radiation and electromagnetic fields, high and low temperatures, corrosive conditions, environments causing embrittlement, and environments containing atomic oxygen. This is an extremely active and vibrant field of research, in particular because it is now possible to create laboratory conditions similar in pressure, temperature and radiation to those found in planetary interiors and in space. In addition, advanced simulation methods, coupled with high-performance computing platforms, now afford predictions - on a first-principles basis - of the properties of materials in extreme environments. Scientists from a broad spectrum of fields are represented, including space science, planetary science, high-pressure research, shock physics, ultrafast science, and energetic materials research.

Download or read book Modeling Microstructural Evolution and the Mechanical Response of Superplastic Materials written by and published by . This book was released on 1993 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: A model has been developed that accounts for grain growth during, superplastic flow and its subsequent influence on stress-strain-strain rate behavior. These studies are experimentally based and have involved two different types of superplastic materials -- a quasi-single phase metal (Coronze 638) and a microduplex metal (ultrahigh-carbon steel - UHCS). In both materials the kinetics of strain-enhanced grain growth have been studied as a function of strain, strain rate and temperature. An equation for the rate of grain growth has been developed that incorporates the influence of temperature. The evolution of the grain size distribution during superplastic deformation has also been investigated. Our model integrates grain growth laws derived from these studies with two mechanism based, rate dependent constitutive laws to predict the stress-strainstrain rate behavior of materials during superplastic deformation. The influence of crain size distribution and its evolution with strain and strain rate on the stress-strain-strain rate behavior has been represented through the use of distributed parameters. The model can capture the stress-strain-strain rate behavior over a wide range of strains and strain rates with a single set of parameters. Many subtle features of the mechanical response of these materials can be adequately predicted.

Download or read book Modeling the Mechanical Behavior and Microstructure Evolutions of Irradiated Nuclear Materials Using the Coupled Kinetic Rate Theory and Continuum Crystal Plasticity Method written by Qianran Yu and published by . This book was released on 2022 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: Microstructure evolution of structural materials under fission/fusion irradiaiton con- ditions lead to significant degradation to their mechanical properties. These effects include an increase in yield stress, plastic localization and accelerated creep rate, etc. Besides, damaged materials inevitably exposing to hydrogen or its isotopes would result in embrittlement and safety problem. Regarding these problems, we in this thesis developed three types of numerical models and attempted to solve each of those. First, a previously developed kMC algorithm based 0-dimentional mean field rate theory model, the stochastic cluster dynamics (SCD), is extended to have 1- dimentional spatial resolution (SRSCD). The SRSCD method is then used to sim- ulate: (1) Zr-hydride nucleation and growth processes under dynamic oxide layer growth conditions; (2) Hydrogen retention in heavy ion irrdiated tungsten. Second, the SCD method is coupled with a general implicit crystal plasticity (CP) formulation (CP/SCD) using a bidirectional variable swap scheme. The CP/SCD model is capable of capturing concurrent irradiation/straining process in materials and is applied to study (1) Irradiation hardening of self-ion irradiated tungsten under tensile loading conditions; (2) Creep and swelling effects of DEMO neutron irradiated iron. Finally, a stochastic solver based on residence time algorithm is developed for solving a typical explicit crystal plasticity (SCP) procedure. The stochasitc nature of SCP is seen to break the symmetry of dislocation slip, which shows potential in studying plastic localization problems.

Download or read book Microstructure And Properties Of Materials Vol 2 written by James C M Li and published by World Scientific Publishing Company. This book was released on 2000-10-09 with total page 454 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the second volume of an advanced textbook on microstructure and properties of materials. (The first volume is on aluminum alloys, nickel-based superalloys, metal matrix composites, polymer matrix composites, ceramics matrix composites, inorganic glasses, superconducting materials and magnetic materials). It covers titanium alloys, titanium aluminides, iron aluminides, iron and steels, iron-based bulk amorphous alloys and nanocrystalline materials.There are many elementary materials science textbooks, but one can find very few advanced texts suitable for graduate school courses. The contributors to this volume are experts in the subject, and hence, together with the first volume, it is a good text for graduate microstructure courses. It is a rich source of design ideas and applications, and will provide a good understanding of how microstructure affects the properties of materials.Chapter 1, on titanium alloys, covers production, thermomechanical processing, microstructure, mechanical properties and applications. Chapter 2, on titanium aluminides, discusses phase stability, bulk and defect properties, deformation mechanisms of single phase materials and polysynthetically twinned crystals, and interfacial structures and energies between phases of different compositions. Chapter 3, on iron aluminides, reviews the physical and mechanical metallurgy of Fe3Al and FeAl, the two important structural intermetallics. Chapter 4, on iron and steels, presents methodology, microstructure at various levels, strength, ductility and strengthening, toughness and toughening, environmental cracking and design against fracture for many different kinds of steels. Chapter 5, on bulk amorphous alloys, covers the critical cooling rate and the effect of composition on glass formation and the accompanying mechanical and magnetic properties of the glasses. Chapter 6, on nanocrystalline materials, describes the preparation from vapor, liquid and solid states, microstructure including grain boundaries and their junctions, stability with respect to grain growth, particulate consolidation while maintaining the nanoscale microstructure, physical, chemical, mechanical, electric, magnetic and optical properties and applications in cutting tools, superplasticity, coatings, transformers, magnetic recordings, catalysis and hydrogen storage.

Download or read book Mechanical Properties and Deformation Behavior of Materials Having Ultra Fine Microstructures written by M. Nastasi and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 616 pages. Available in PDF, EPUB and Kindle. Book excerpt: In an attempt to meet the demand for new ultra-high strength materials, the processing of novel material configurations with unique microstructure is being explored in systems which are further and further from equilibrium. One such class of emerging materials is the so-called nanophased or nanostructured materials. This class of materials includes metals and alloys, ceramics, and polymers characterized by controlled ultra-fine microstructural features in the form oflayered, fibrous, or phase and grain distribution. While it is clear that these materials are in an early stage of development, there is now a sufficient body of literature to fuel discussion of how the mechanical properties and deformation behavior can be controlled through control of the microstructure. This NATO-Advanced Study Institute was convened in order to assess our current state of knowledge in the field of mechanical properties and deformation behavior in materials with ultra fine microstructure, to identify opportunities and needs for further research, and to identify the potential for technological applications. The Institute was the first international scientific meeting devoted to a discussion on the mechanical properties and deformation behavior of materials having grain sizes down to a few nanometers. Included in these discussions were the topics of superplasticity, tribology, and the supermodulus effect. Lectures were also presented which covered a variety of other themes including synthesis, characterization, thermodynamic stability, and general physical properties.

Download or read book Mechanical and Creep Behavior of Advanced Materials written by Indrajit Charit and published by Springer. This book was released on 2017-02-04 with total page 299 pages. Available in PDF, EPUB and Kindle. Book excerpt: This collection commemorates the occasion of the honorary symposium that celebrated the 75th birthday and lifelong contributions of Professor K.L. Murty. The topics cover the present status and recent advances in research areas in which he made seminal contributions. The volume includes articles on a variety of topics such as high-temperature deformation behaviors of materials (elevated temperature creep, tensile, fatigue, superplasticity) and their micromechanistic interpretation, understanding mechanical behavior of HCP metals/alloys using crystallographic texture, radiation effects on deformation and creep of materials, mechanical behavior of nanostructured materials, fracture and fracture mechanisms, development and application of small-volume mechanical testing techniques, and general structure-property correlations.

Download or read book Microstructure Evolution During Irradiation Volume 439 written by Ian M. Robertson and published by . This book was released on 1997-06-25 with total page 770 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book from MRS discusses the evolution of a material's microstructure as a result of its interaction with energetic particles such as ions, neutrons or electrons. The book is inter-disciplinary and emphasizes all classes of materials including metals, intermetallic compounds, ceramics, polymers, superconductors, semiconductors and insulators. A strong focus is placed on experimental techniques for measuring and quantifying damage and microstructure changes, and on computer simulation techniques for predicting and understanding this phenomena. Topics include: ion-implantation damage in semiconductors; radiation damage in metals; radiation damage in ceramics; radiation effects in polymers and beam-induced effects.

Download or read book Properties and Microstructure written by R. K. MacCrone and published by Elsevier. This book was released on 2013-10-22 with total page 473 pages. Available in PDF, EPUB and Kindle. Book excerpt: Treatise on Materials Science and Technology, Volume 11: Properties And Microstructure covers the parameters important to understanding microstructural effects. The book discusses the direct observation and characterization of defects in materials; the cause and effect of crystal defects in silicon integrated circuits; as well as the microstructure of some noncrystalline ceramics. The text also describes microstructural defects in the important semiconductors silicon and germanium, microstructural effects in glasses, microstructural effects on the mechanical properties of ceramics, and finally, microstructures in ferrites. Materials scientists, materials engineers, and graduate students taking related courses will find the book invaluable.

Download or read book Microstructures of Irradiated Materials written by H. S. Rosenbaum and published by Elsevier. This book was released on 2013-10-22 with total page 189 pages. Available in PDF, EPUB and Kindle. Book excerpt: Treatise on Materials Science and Technology, Volume 7: Microstructures of Irradiated Materials covers the effects of irradiation on the microstructures of solids. The book introduces basic concepts and terminology and discusses the physical effects of irradiation, those having to do with the physical displacement of atoms and the subsequent atom rearrangements that can occur either by momentum transfer or by diffusional phenomena. The text also describes the chemical effects of irradiation, including diffusion, phase changes, precipitation of solute atoms, transmutations, and combinations of these. Some of the complex situations encountered in some nuclear fuels and structural materials of practical concern are also encompassed. Metallurgists, metallurgical engineers, ceramists, materials scientists, and people interested in the nuclear field will find the book invaluable.

Download or read book Microstructural Processes in Irradiated Materials 2000 written by Glenn E. Lucas and published by Cambridge University Press. This book was released on 2014-06-05 with total page 490 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book reveals progress on a broad range of fronts in radiation damage. Fundamental understanding of microstructural evolution during irradiation is being significantly advanced by improving methods for microstructural characterization coupled with atomistic and multiscale modeling of the defect production and evolution processes. Characterization of microstructures by techniques such as 3D atom probe, high-resolution electron microscopy and positron annihilation are unveiling the nature of numerous types of defects on size scales in the nanometer range. This understanding of microstructural evolution is shedding light on technological problems associated with degradation in nuclear power systems as well as showing opportunities to use radiation to produce useful structures at the nanoscale for a host of applications. It brings together researchers to promote the cross-fertilization of ideas and techniques. Both experimental and theoretical studies, including atomistic and mesoscale modeling, are presented. Topics include: irradiated metals; austenitic stainless steels; radiation effects; irradiated ceramics; ferritic and pressure vessel steels; ion beam synthesis of nanostructures and thin layers; ion-solid interactions for optoelectronics/ photonics and semiconductors and electronic materials.

Download or read book Radiation Induced Effects on Microstructure written by and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Irradiation of materials with particles that are sufficiently energetic to create atomic displacements can induce significant microstructural alteration, ranging from crystalline-to-amorphous phase transitions to the generation of large concentrations of point defect or solute aggregates in crystalline lattices. These microstructural changes typically cause significant changes in the physical and mechanical properties of the irradiated material. A variety of advanced microstructural characterization tools are available to examine the microstructural changes induced by particle irradiation, including electron microscopy, atom probe field ion microscopy, X-ray scattering and spectrometry, Rutherford backscattering spectrometry, nuclear reaction analysis, and neutron scattering and spectrometry. Numerous reviews, which summarize the microstructural changes in materials associated with electron and heavy ion or neutron irradiation, have been published. These reviews have focused on pure metals as well as model alloys, steels, and ceramic materials. In this chapter, the commonly observed defect cluster morphologies produced by particle irradiation are summarized and an overview is presented on some of the key physical parameters that have a major influence on microstructural evolution of irradiated materials. The relationship between microstructural changes and evolution of physical and mechanical properties is then summarized, with particular emphasis on eight key radiation-induced property degradation phenomena. Typical examples of irradiated microstructures of metals and ceramic materials are presented. Radiation-induced changes in the microstructure of organic materials such as polymers are not discussed in this overview.

Download or read book Mechanical Properties and Radiation Tolerance of Metallic Multilayers written by Nan Li and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: High energy neutron and proton radiation can induce serious damage in structural metals, including void swelling and embrittlement. Hence the design of advanced metallic materials with significantly enhanced radiation tolerance is critical for the application of advanced nuclear energy systems. The goals of this dissertation are to examine the fundamental physical mechanisms that determine the responses of certain metallic multilayers, with ultra-high density interface structures, to plastic deformation and high fluence He ion irradiation conditions. This dissertation focuses on the investigation of mechanical and radiation responses of Al/Nb and Fe/W multilayers. Radiation induced microstructural evolution in Cu and Cu/Mo multilayer films are briefly investigated for comparisons. Al/Nb multilayer films were synthesized by magnetron sputtering at room temperature. The interface is of Kurdjumov-Sachs orientation relationship. In situ nanoindentation inside a transmission electron microscope (TEM) reveal that interfaces act as strong barriers for dislocation transmission and dislocations climb along the Al/Nb interfaces at a much higher velocity than in bulk. The evolution of microstructure and mechanical properties of Al/Nb multilayers has been investigated after helium ion irradiations: 100 keV He+ ions with a dose of 6x10^16/cm2. When layer thickness, h, is greater than 25 nm, hardness barely changes, whereas radiation hardening is more significant at smaller h. This study shows that miscible fcc/bcc interface with large positive heat of mixing is not stable during ion irradiation. In parallel we investigate sputtered Fe/W multilayers. Film hardness increases with decreasing h, and approaches a maximum of 12.5 GPa when h = 1 nm. After radiation, radiation hardening is observed in specimens when h>/= 5 nm, however, hardness barely changes in irradiated Fe/W 1 nm specimens due to intermixing. In comparison, Cu/Mo 5 nm multilayers with immiscible interface has also been investigated after helium ion irradiations. Interfaces exhibit significantly higher helium solubility than bulk. He/vacancy ratio affects the formation and distribution of He bubbles. The greater diameter of He bubbles in Cu than Mo originates from the ease of bubble growth in Cu via punching of interstitial loops. Finally, helium bubble migration and growth mechanisms were investigated in irradiated Cu (100) single crystal films via in situ heating inside a TEM. The activation energy for bubble growth is ~ 0.02 eV at low temperature. At higher temperatures, the activation energy for bubble coalescence is ~ 0.22 eV inside crystal, and 0.34 eV close to surface. The migration mechanisms of helium bubbles involve continuous as well as Brownian movement.

Download or read book Microstructure and Mechanical Behaviour of Materials written by Haicheng Gu and published by . This book was released on 1986 with total page 512 pages. Available in PDF, EPUB and Kindle. Book excerpt: