Download or read book The Low Temperature Thermally Activated Deformation Mechanisms for BCC Magnesium lithium aluminum Alloy written by Mohamed Osama Abo El-Fotoh and published by . This book was released on 1967 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1974 with total page 992 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mechanism of Low temperature Deformation in Quenched Aluminum magnesium Alloys written by Y. V. R. K. Prasad and published by . This book was released on 1970 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1970 with total page 992 pages. Available in PDF, EPUB and Kindle. Book excerpt: NSA is a comprehensive collection of international nuclear science and technology literature for the period 1948 through 1976, pre-dating the prestigious INIS database, which began in 1970. NSA existed as a printed product (Volumes 1-33) initially, created by DOE's predecessor, the U.S. Atomic Energy Commission (AEC). NSA includes citations to scientific and technical reports from the AEC, the U.S. Energy Research and Development Administration and its contractors, plus other agencies and international organizations, universities, and industrial and research organizations. References to books, conference proceedings, papers, patents, dissertations, engineering drawings, and journal articles from worldwide sources are also included. Abstracts and full text are provided if available.
Download or read book Aluminium Abstracts written by and published by . This book was released on 1968 with total page 530 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effect of Temperature on the Yield Strength for Basal Slip in Lithium Alpha Solid Solution of Magnesium Single Crystals written by Richard Morrell Quimby and published by . This book was released on 1961 with total page 1 pages. Available in PDF, EPUB and Kindle. Book excerpt: An investigation was conducted on the deformation of single crystals of alpha solid solution (12.5 at-% Li in Mg) specially oriented for basal slip. Crystals were tested in tension over the range of temperatures between 77 and 645 K. The alloy has a critical resolved shear-stress at least ten times that of pure Mg. Whereas the critical resolved shear-stress was temperature dependent below 250 K, it was relatively constant over the higher temperature range. Above 400 K all crystals fractured on the prismatic planes following duplex prismatic slip. Twinning, kinking and accommodation bending was observed in areas adjacent to subgrain boundaries and the shear-stress vs shear-strain curves for the crystals were correlated with the various types of deformation markings observed on the surfaces of the strain specimens. The thermally activated deformation mechanism below 250 K probably arises from the dislocation intersection process whereas the higher temperature athermal behavior is thought to be a result of short-range ordering. (Author).
Download or read book Plastic Deformation Mechanism in Rolled AZ31 Magnesium Alloy at Room Temperature written by Yuzhi Zhu and published by . This book was released on 2020 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt: Magnesium, as the lightest structural metal, is attracting researchers' attention in recent years. However, its further application is limited by some shortcomings, like mechanical anisotropy and poor formability, which is ascribed to the low-symmetric HCP structure.The main objective of this dissertation is to unveil the deformation mechanisms of dislocation slip and deformation twinning in rolled AZ31 magnesium alloy during plastic deformation at ambient temperature. Characterization studies by electron backscattered diffraction (EBSD) and transmission electron microscopy (TEM), and theoretical calculations with MATLAB are used to analyze the deformation behaviors.Quasi in-situ EBSD analysis shows that under an unfavorable loading condition for twinning activation, {101Ì52} tensile twins still can be activated but most of them can merely further thicken. While under repeated tensile and compressive strains, the twinning/detwinning process occurs with the sequence of nucleation, propagation, thickening, thinning, shortening, and vanishing. HRTEM analysis shows an intense atomic misalignment near {101Ì52} tensile twin boundaries, especially near the twin tip, ascribed to the mobility of twinning dislocations. TEM analysis also shows that type basal slips are activated at the early deformation stage. type pyramidal dislocations are not observed at low deformation strain but proved to be activated at the late deformation stage. During the whole deformation process, no type prismatic slip is observed by TEM. The Schmid factor analysis explains the phenomena. GND calculation gives us a possibility to evaluate the slip behavior and make it visual in bulk samples. The slip activations depend on both the grain orientations and the strain conditions in the adjunct grains. The increased GND density is accompanied by an increased strain. type basal slips and type pyramidal slips dominate during the deformation process. type prismatic GND density only increases at the late deformation stage. Furthermore, prismatic GNDs prefer to accumulate near grain boundaries and twin boundaries. IGMA analysis explains the slip behaviors in the matrix region and the twinning area. The activation of type prismatic slips inside {101Ì52} tensile twins is easier than that in the matrix region.
Download or read book High Strain Rate Deformation in FCC Metals and Alloys written by and published by . This book was released on 1985 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The effect of strain rate, and particularly of high strain rates, on deformation mechanisms in materials is of fundamental interest to those who model and analyze dynamic loading. In many materials the strain rate sensitivity is known to increase dramatically when the strain rate is raised above approx. 103 s−1. This increase has been interpreted previously as a transmission in deformation mechanism from thermal activation control at low strain rate to dislocation drag control at high strain rate. In copper, copper-aluminum alloys and stainless steel, recent measurements have shown that the increased rate sensitivity found at high strain rates is not due to a transition in deformation mechanism but rather can be explained with standard thermal activation theory. These findings and their implications regarding the formulation of constitutive behavior are presented.
Download or read book Commencement Programme written by University of California, Berkeley and published by . This book was released on 1967 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Deformation and Failure Mechanisms of a Modified Commercial Aluminum Alloy at Elevated Temperatures written by William Paul Green and published by . This book was released on 2004 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt: Superplastic aluminum alloys have been the subject of recent research in the automotive industry for several reasons. First, the formability of such alloys under superplastic forming (SPF) conditions is quite good; second, the potential weight reduction associated with formed aluminum sheet as compared to traditional steel sheet is particularly important for automotive applications. Unfortunately, SPF-grade aluminum is relatively expensive, and the typical SPF process is expensive and time-consuming because of the high temperatures and slow strain rates involved. The present study investigates the potential for forming AA5083, the most common commercial alloy for SPF operations, at reduced temperatures and increased strain-rates. The deformation and failure mechanisms under these conditions are examined in a modified AA5083 material and are compared with data from unmodified AA5083. A new method of presenting creep transient data is presented and is used to determine deformation mechanisms at elevated temperatures. A modified AA5083 alloy produced by continuous casting (CC), and containing a small addition of Cu, was studied. This small addition of Cu causes the formation of Mg2Cu and MgCu2 intermetallic particles, which produce incipient melting. It is proposed that these low-melting-temperature phases may reside at grain boundaries and enhance grain-boundary sliding at low temperatures, which may explain the improved ductility of the Cu-containing alloy. Ductility variations for the Cu-containing alloy are also explored. The differences in tensile ductility between the Cu-containing AA5083 and unmodified AA5083 materials, produced by both CC and direct-chill (DC) casting, are related to differences in cavitation behavior. The final part of the present work is a study on the effect of various heat treatment schedules on the constituent particle distribution in AA5083. It is shown that a simple one-day aging treatment at a moderate temperature can effectively reduce the interparticle spacing. This may lead to a finer recrystallized grain size [1] and, thus, improve superplastic properties.
Download or read book List of References on Nuclear Energy written by International Atomic Energy Agency and published by . This book was released on 1968 with total page 664 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book List of References on Nuclear Energy written by and published by . This book was released on 1968 with total page 1228 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Metallurgical Abstracts written by Institute of Metals and published by . This book was released on 1967 with total page 1172 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Transactions written by Metallurgical Society of AIME. and published by . This book was released on 1968 with total page 1398 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book ASM Specialty Handbook written by M. M. Avedesian and published by ASM International. This book was released on 1999-01-01 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: This ASM Handbook is the most comprehensive collection of engineering information on this important structural material published in the last sixty years. Prepared with the cooperation of the International Magnesium Association, it presents the current industrial practices and provides information and data about the properties and performance of magnesium alloys. Materials science and engineering are covered, including processing, properties, and commercial uses.
Download or read book Inorganic Materials Research Division Annual Report written by Lawrence Radiation Laboratory. Inorganic Materials Research Division and published by . This book was released on 1964 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Metals Abstracts written by and published by . This book was released on 1983 with total page 1058 pages. Available in PDF, EPUB and Kindle. Book excerpt:
