Download or read book Microstructural Characteristics and Dynamic Recrystallization Behavior of TiAl Based Alloy During High Temperature Deformation written by and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mechanisms and Effect of Microstructure on High Temperature Deformation of Gamma TiAl Based Alloys written by Karthikeyan Subramanian and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Despite the large body of work done in the area of high-temperature creep, the present understanding of creep mechanisms and the effect of alloying and microstructure is limited. The first part of this investigation concentrates on the creep behavior in the equiaxed microstructure of gamma-TiAl alloys, to understand the mechanisms and develop a physically-based model for creep in the gamma phase. A modification of the classic jogged-screw model has been previously adopted to explain observations of 1/2[110]-type jogged-screw dislocations in equiaxed Ti-48Al under creep conditions. The goal of this study is to verify and validate the parameters and functional dependencies that have been assumed in that model. The original solution has been reformulated with the aid of analytical modeling, numerical simulations and Transmission Electron Microscopy. Both experiment and theory lead to an excellent prediction of creep rates and stress exponents. In the second part of this study creep behavior of the fully lamellar TiAl alloys is investigated. Dislocation structures similar to those observed in the equiaxed alloys suggests that the jogged-screw model can be adapted for lamellar alloys. The aim of the model is to predict the unique creep phenomenology of fully lamellar alloys. The strengths and shortcomings of the model are discussed. Probable low stress creep mechanisms are also suggested. The origin of fully lamellar alloys' superior creep properties stems from the constrained nature of deformation in the lamellae. The results from stress drop experiments are analysed to explore the origin of the large back stresses associated with the fully lamellar alloys. Reduction of the lamellar spacing is proposed as the best way to lower creep rates. In the final part of this study, the microstructural stability of lamellar alloys during exposure to creep conditions is investigated. A detailed investigation of the creep behavior of the aged (stabilized) and unaged (unstabilized) alloys was carried out and subsequent TEM studies were done to characterize the microstructural changes during creep. Continued loss of metastable alpha-2 is proposed as the reason for the larger strain rates in all stages of creep for the alloy in the unaged condition. Dynamic recrystallization and the formation of equiaxed gamma grains are discussed. These results suggest that microstructural stability is critically important in order to achieve the highest possible creep strengths. The effect of microalloying and the role of precipitation hardening in creep are investigated. The probable mechanisms of primary, secondary and tertiary creep are discussed and methods for improving the creep properties are suggested.
Download or read book Introduction to Texture Analysis written by Olaf Engler and published by CRC Press. This book was released on 2009-11-16 with total page 490 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first edition of Introduction to Texture Analysis: Macrotexture, Microtexture, and Orientation Mapping broke new ground by collating seventy years worth of research in a convenient single-source format. Reflecting emerging methods and the evolution of the field, the second edition continues to provide comprehensive coverage of the concepts, pra
Download or read book Effects of Zr and V on Microstructure and Hot Deformation Behavior of 7150 Aluminum Alloys written by Cangji Shi and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Après avoir été allié avec du Zr de 0 à 0,19% en poids, les résultats ne montrent pas de variation significative du pic de la contrainte d'écoulement ou de l'énergie d'activation entre l'alliage de base 7150 et l'alliage contenant 0,04% en poids de Zr.
Download or read book Gamma Titanium Aluminides written by Young-Won Kim and published by Minerals, Metals, & Materials Society. This book was released on 1995 with total page 1036 pages. Available in PDF, EPUB and Kindle. Book excerpt: This two-volume publication is a comprehensive update of the fundamental and practical issues confronting the research, development and application of gamma titanium aluminides.
Download or read book Fundamentals of Creep in Metals and Alloys written by Michael E. Kassner and published by Elsevier. This book was released on 2004-04-06 with total page 289 pages. Available in PDF, EPUB and Kindle. Book excerpt: * Numerous line drawings with consistent format and units allow easy comparison of the behavior of a very wide range of materials * Transmission electron micrographs provide a direct insight in the basic microstructure of metals deforming at high temperatures * Extensive literature review of over 1000 references provide an excellent reference document, and a very balanced discussionUnderstanding the strength of materials at a range of temperatures is critically important to a huge number of researchers and practitioners from a wide range of fields and industry sectors including metallurgists, industrial designers, aerospace R&D personnel, and structural engineers. The most up-to date and comprehensive book in the field, Fundamentals of Creep in Metals and Alloys discusses the fundamentals of time-dependent plasticity or creep plasticity in metals, alloys and metallic compounds. This is the first book of its kind that provides broad coverage of a range of materials not just a sub-group such as metallic compounds, superalloys or crystals. As such it presents the most balanced view of creep for all materials scientists. The theory of all of these phenomena are extensively reviewed and analysed in view of an extensive bibliography that includes the most recent publications in the field. All sections of the book have undergone extensive peer review and therefore the reader can be sure they have access to the most up-to-date research, fully interrogated, from the world's leading investigators.· Numerous line drawings with consistent format and units allow easy comparison of the behavior of a very wide range of materials· Transmission electron micrographs provide a direct insight in the basic microstructure of metals deforming at high temperatures· Extensive literature review of over 1000 references provide an excellent reference document, and a very balanced discussion
Download or read book High Temperature Deformation Behaviour of an Al Mg Si Cu Alloy and Its Relation to the Microstructural Characteristics written by Roger Nicol Carrick and published by . This book was released on 2009 with total page 189 pages. Available in PDF, EPUB and Kindle. Book excerpt: The microstructural evolution and mechanical properties at elevated temperatures of a recently fabricated fine-grained AA6xxx aluminium sheet were evaluated and compared to the commercially fabricated sheet of the same alloy in the T4P condition. The behaviour of the fine-grained and T4P sheets was compared at elevated temperatures between 350°C and 550°C, as well as room temperature. Static exposure to elevated temperatures revealed that the precipitate structure of the fine-grained material did not change extensively. The T4P material, however, underwent extensive growth of precipitates, including a large amount of grain boundary precipitation. At room temperature, the T4P material deformed at much higher stresses than the FG material, but achieved lower elongations. Deformation at elevated temperatures revealed that the fine-grained material achieved significantly larger elongations to failure than the T4P material in the temperature range of 350°C-450°C. Both materials behaved similarly at 500°C and 550°C. Above 500°C, the grain size was greatly reduced in the T4P material, and only a slightly increased in the fine-grained material. At temperatures above 450°C, the elongation to failure in both materials generally increased with increasing strain-rate. The poor performance of the T4P material at low temperatures was attributed to the precipitate characteristics of the sheet, which lead to elevated stresses and increased cavitation. The deformation mechanism of both materials was found to be controlled by dislocation climb, accommodated by the self diffusion of aluminium at 500°C and 550°C. The deformation mechanism in the fine-grained material transitioned to power law breakdown at lower temperatures. At 350°C to 450°C, the T4P material behaved similarly to a particle hardened material with an internal stress created by the precipitates. The reduction in grain size of the T4P material after deformation at 500°C and 550°C was suggested to be caused by dynamic recovery/recrystallization. The role of a finer grain-size in the deformation behaviour at elevated temperatures was mainly related to enhanced diffusion through grain boundaries. The differences in the behaviour of the two materials were mainly attributed to the difference in the precipitation characteristics of the materials.
Download or read book Light Weight Alloys written by Maurizio Vedani and published by MDPI. This book was released on 2020-05-22 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt: There is growing interest in light metallic alloys for a wide number of applications owing to their processing efficiency, processability, long service life, and environmental sustainability. Aluminum, magnesium, and titanium alloys are addressed in this Special Issue, however, the predominant role played by aluminum. The collection of papers published here covers a wide range of topics that generally characterize the performance of the alloys after manufacturing by conventional and innovative processing routes.
Download or read book Gamma Titanium Aluminide Alloys written by Fritz Appel and published by John Wiley & Sons. This book was released on 2011-10-17 with total page 763 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first book entirely dedicated to the topic emphasizes the relation between basic research and actual processing technologies. As such, it covers complex microstructures down to the nanometer scale, structure/property relationships and potential applications in key industries. From the contents: * Constitution * Thermophysical Constants * Phase Transformations and Microstructures * Deformation Behaviour * Strengthening Mechanisms * Creep * Fracture Behaviour * Fatigue * Oxidation Resistance and Related Issues * Alloy Design * Ingot Production and Component Casting * Powder Metallurgy * Wrought Processing * Joining * Surface Hardening * Applications and Component Assessment
Download or read book Functional and Functionally Structured Materials V written by Yafang Han and published by Trans Tech Publications Ltd. This book was released on 2021-06-22 with total page 1122 pages. Available in PDF, EPUB and Kindle. Book excerpt: Selected peer-reviewed full text papers from the 21st Chinese Materials Conference 2020 (CMC 2020) Selected peer-reviewed papers from the 21st Chinese Materials Conference 2020(CMC2020), November 17-22, 2020, Beijing, China
Download or read book Titanium Alloys written by Valentin N. Moiseyev and published by CRC Press. This book was released on 2005-07-13 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt: This text offers previously elusive information on state-of-the-art Russian metallurgic technology of titanium alloys. It details their physical, mechanical, and technological properties, as well as treatments and applications in various branches of modern industry, particularly aircraft and aerospace construction. Titanium Alloys: Russian Aircraft and Aerospace Applications addresses all facets of titanium alloys in aerospace and aviation technology, including specific applications, fundamentals, composition, and properties of commercial alloys. It is useful for all students and researchers interested in the investigation and applications of titanium.
Download or read book Processing Microstructure Property Relationships in Advanced Intermetallics written by D. Hardwick and published by . This book was released on 1998 with total page 39 pages. Available in PDF, EPUB and Kindle. Book excerpt: Microstructural evolution in near-gamma TiAl alloys during hot working is a complex interaction involving solid state diffusion, dynamic recrystallization and non-uniform strain accommodation. Compression workability testing, coupled with extensive metallographic characterization, has been used to study the evolution of microstructural refinement and chemical homogeneity in three near-gamma TiAl alloys: Ti-46Al-0.2B, Ti-48Al-0.2B and Ti-48Al-2Mo-0.2B. Hot working of materials that had undergone an homogenization heat treatment resulted in the breakup of the initial fully lamellar microstructures into isolated islands of lamellae surrounded by fine bands of dynamically recrystallized grains. Using material that had been initially forged to a strain of 0.9 at 1150 deg C with a strain rate of 10(exp -3)/sec, the effect of additional thermal and mechanical working steps was examined. Particular attention was paid to the effect of strain path on the behavior of the remnant lamellar colonies. Strain in the same direction as the first forging had little effect in breaking-up lamellar colonies lying in the plane of the forging while strain applied perpendicular to this direction was more effective in encouraging these features to undergo enough strain to recrystallize.
Download or read book The Science Technology and Application of Titanium written by R. I. Jaffee and published by Elsevier. This book was released on 2013-09-24 with total page 1225 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Science, Technology and Application of Titanium contains the proceedings of an International Conference organized by the Institute of Metals, The Metallurgical Society of AIME, and the American Society for Metals in association with the Japan Institute of Metals and the Academy of Sciences of the USSR and held at the Royal Festival Hall in London, on May 21-24, 1968. The papers explore scientific and technological developments as well as applications of titanium and cover topics ranging from processing of titanium to its chemical and environmental behavior, physics, thermodynamics, and kinetics. Deformation and fracture, phase transformations and heat treatment, and alloying are also discussed. This book is comprised of 114 chapters and begins with an overview of the titanium industry in Europe and the United States. The reader is then introduced to primary and secondary fabrication of titanium; corrosion and oxidation; physical properties of titanium alloys; interaction of titanium with elements of the periodic system; and elastic interactions between dislocations and twin and grain boundaries in titanium. The crystallography of deformation twinning in titanium is also examined, along with superplasticity and transformation plasticity in titanium. The remaining chapters focus on interstitial strengthening of titanium alloys; mechanism of martensitic transformation in titanium and its alloys; phase relationships in titanium-oxygen alloys; strengthening of titanium alloys by shock deformation; and titanium hot forming. This monograph will be of interest to chemists and metallurgists.
Download or read book Crystal Plasticity Finite Element Methods written by Franz Roters and published by John Wiley & Sons. This book was released on 2011-08-04 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written by the leading experts in computational materials science, this handy reference concisely reviews the most important aspects of plasticity modeling: constitutive laws, phase transformations, texture methods, continuum approaches and damage mechanisms. As a result, it provides the knowledge needed to avoid failures in critical systems udner mechanical load. With its various application examples to micro- and macrostructure mechanics, this is an invaluable resource for mechanical engineers as well as for researchers wanting to improve on this method and extend its outreach.
Download or read book Metal Surfaces written by Roberto Montanari and published by MDPI. This book was released on 2021-08-31 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt: This collection covers the physical and chemical phenomena of metal surfaces, including surface modifications and treatments. It is targeted at researchers working in materials science and also at newcomers to the research field of metal surfaces and surface analysis.
Download or read book Texture and Microstructure Development in Al 2 Mg During High Temperature Deformation written by and published by . This book was released on 1990 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: The high rate sensitivity of the flow stress that is exhibited by alloys under solute drag control, such as Al-Mg at high temperatures, influences texture development because more slip systems contribute to deformation. Al-2% Mg was tested in channel-die compression, i.e. idealized rolling, at 290°C and 400°C, at strain rates from 10−1/s to 10−5/s. The texture development in rolling predicted by polycrystal plasticity simulation indicates that the brass component increases while the copper component decreases when the rate sensitivity is raised. The experimental results are in good agreement with this prediction. In addition, cube component appears when microstructural change occurs due to dynamic recrystallization. This microstructural change leads to the shift from {l angle}011{r angle} to {l angle}001{r angle} fiber texture in free compression at high temperature. 18 refs., 13 figs.
Download or read book Modelling the Deformation Recrystallization and Microstructure Related Properties in Metals written by Jurij J Sidor and published by Mdpi AG. This book was released on 2021-11-15 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the special issue related to Modelling the Deformation, Recrystallization and Microstructure-Related Properties in Metals, we presented a wide spectrum of articles dealing with modelling of microstructural aspects involved in deformation and recrystallization as well as simulation of microstructure-based and texture-based properties in various metals. The latest advances in the theoretical interpretation of mesoscopic transformations based on experimental observations were partially discussed in the current special issue. The studies dealing with the modelling of structure-property relationships are likewise analyzed in the present collection of manuscripts. The contributions in the current collection evidently demonstrate that the properties of metallic materials are microstructure dependent and therefore the thermomechanical processing (TMP) of the polycrystalline aggregates should be strictly controlled to guarantee the desired bunch of qualities. Given this, the assessment of microstructure evolution in metallic systems is of extraordinary importance. Since the trial-error approach is a time-consuming and quite expensive methodology, the materials research community tends to employ a wide spectrum of computational approaches to simulate each chain of TMP and tune the processing variables to ensure the necessary microstructural state which will provide desired performance in the final product. Although many hidden facets of various technological processes and related microstructural changes were revealed in the submitted works by employing advanced computational approaches, nevertheless, the contributions collected in this issue clearly show that further efforts are required in the field of modelling to understand the complexity of material's world. The final goal of modelling efforts might be a development of a comprehensive model, which will be capable of describing many aspects of microstructure evolution during thermomechanical processing.
