Download or read book Effect of Surface Condition on Ductile to brittle Transition Temperature of Tungsten written by Joseph R. Stephens and published by . This book was released on 1961 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NASA Technical Note written by and published by . This book was released on 1968 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effects of Interstitial Impurities on the Low temperature Tensile Properties of Tungsten written by Joseph R. Stephens and published by . This book was released on 1964 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: A study was undertaken to determine the effects of the interstitial impurities oxygen and carbon on the mechanical properties of polycrystalline tungsten and high-purity tungsten single crystals. Results of tensile tests showed that additions of both oxygen and carbon to polycrystalline tungsten produced a marked increase in the ductile to brittle transition temperature. Oxygen and carbon produced a much smaller increase in the transition temperature of the single-crystal specimens compared with equivalent amounts of impurities in the polycrystalline specimens. Addition of oxygen to polycrystalline tungsten lowered both the ultimate tensile strength and the yield strength, but had no measurable effect on the strength properties of single-crystal specimens. Carbon additions to both polycrystalline and single-crystal specimens did not affect the ultimate tensile strength; however, a large increase in the yield strength resulted. The results suggest that oxygen embrittlement in tungsten is caused by grain-boundary segregation, while carbon embrittlement results from an interaction between carbon atoms and dislocations within the tungsten lattice.
Download or read book Effect of Oxygen on Mechanical Properties of Tungsten written by Joseph R. Stephens and published by . This book was released on 1963 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effect of oxygen on the mechanical properties of commercial polycrystalline tungsten and zone-refined single-crystal tungsten was evaluated by means of tensile tests of oxygen-doped specimens in the ductile-to-brittle transition temperature range. The effect of oxygen as a surface oxide that might be encountered in normal working and forming operations was evaluated by means of a three-point loading bend test at room temperature. Oxygen doping of the polycrystalline and single-crystal tensile specimens was accomplished by equilibrating the specimen and tungsten oxide powder in a sealed tungsten capsule at high temperatures. A desired oxygen concentration could be achieved by varying the time of doping in the temperature range of 3000 to 3600 F. Results showed that the commercial recrystallized rods containing 4 parts per million (ppm) oxygen had a ductile-to-brittle transition temperature (based on 50-percent reduction in area) of 4500 F. Increasing the oxygen concentration to 10, 30, and 50 ppm increased the transition temperature to 6600, 840, and 1020 F, respectively. The oxygen additions also produced a progressive lowering of the ultimate tensile strength. The mechanism for the effect of oxygen on the transition temperature and ultimate tensile strength is believed to be that of segregation of the oxygen atoms at the grain boundaries. The oxygen additions also caused a progressive lowering of the yield strength, which is believed to result from the interaction of oxygen with carbon atoms or other impurity atoms present in the tungsten lattice.
Download or read book Tungsten Research and Development Review written by J. L. Ratliff and published by . This book was released on 1963 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt: Government-sponsored tungsten research and development efforts encompass a broad rage of technological activities. Typifying the extreme limits of efforts since January, 1960, studies have ranged from preparation of unalloyed metal to development of high-integrity fabricated shapes of tungsten-base materials. Nine major areas outline the broad over-all effort, and each is summarized within this report by brief technical discussions of 104 separate studies on 79 research programs. Included are preparation of metal, consolidation, primary and secondary working, joining, fabrication and performance of rocket nozzles, oxidation and other high-temperature reactions, protective coatings, properties, and physical metallurgy.
Download or read book Thermally Activated Mechanisms in Crystal Plasticity written by D. Caillard and published by Elsevier. This book was released on 2003-09-08 with total page 453 pages. Available in PDF, EPUB and Kindle. Book excerpt: KEY FEATURES: - A unified, fundamental and quantitative resource. The result of 5 years of investigation from researchers around the world - New data from a range of new techniques, including synchrotron radiation X-ray topography provide safer and surer methods of identifying deformation mechanisms - Informing the future direction of research in intermediate and high temperature processes by providing original treatment of dislocation climb DESCRIPTION: Thermally Activated Mechanisms in Crystal Plasticity is a unified, quantitative and fundamental resource for material scientists investigating the strength of metallic materials of various structures at extreme temperatures. Crystal plasticity is usually controlled by a limited number of elementary dislocation mechanisms, even in complex structures. Those which determine dislocation mobility and how it changes under the influence of stress and temperature are of key importance for understanding and predicting the strength of materials. The authors describe in a consistent way a variety of thermally activated microscopic mechanisms of dislocation mobility in a range of crystals. The principles of the mechanisms and equations of dislocation motion are revisited and new ones are proposed. These describe mostly friction forces on dislocations such as the lattice resistance to glide or those due to sessile cores, as well as dislocation cross-slip and climb. They are critically assessed by comparison with the best available experimental results of microstructural characterization, in situ straining experiments under an electron or a synchrotron beam, as well as accurate transient mechanical tests such as stress relaxation experiments. Some recent attempts at atomistic modeling of dislocation cores under stress and temperature are also considered since they offer a complementary description of core transformations and associated energy barriers. In addition to offering guidance and assistance for further experimentation, the book indicates new ways to extend the body of data in particular areas such as lattice resistance to glide.
Download or read book Crystallographic Texture of Materials written by Satyam Suwas and published by Springer. This book was released on 2016-09-10 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Providing a comprehensive and invaluable overview of the basics of crystallographic textures and their industrial applications, this book covers a broad range of both structural and functional materials. It introduces the existing methods of representation in an accessible manner and presents a thorough overview of existing knowledge on texture of metallic materials. Texture analysis has widespread use in many industries, and provides crucial input towards the development of new materials and products. There has been rapid growth in the science and art of texture analysis in the last few decades. Other topics addressed within this book include recent research on texture in thin films and non-metals, and the dependence of material properties on texture, and texture control in some engineering materials. This book constitutes an invaluable reference text for researchers and professionals working on texture analysis in metallurgy, materials science and engineering, physics and geology. By using content selectively, it is also highly accessible to undergraduate students.
Download or read book Fatigue and Fracture written by F. C. Campbell and published by ASM International. This book was released on 2012-01-01 with total page 699 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This book emphasizes the physical and practical aspects of fatigue and fracture. It covers mechanical properties of materials, differences between ductile and brittle fractures, fracture mechanics, the basics of fatigue, structural joints, high temperature failures, wear, environmentally-induced failures, and steps in the failure analysis process."--publishers website.
Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1976-03 with total page 938 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Monthly Catalog of United States Government Publications written by and published by . This book was released on with total page 1284 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book High Temperature Materials Program written by and published by . This book was released on 1963-01-25 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effects of Solutes on the Ductile to brittle Transition of Refractory Metals written by George T. Hahn and published by . This book was released on 1962 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt: There appear to be two ways in which interstitials promote brittle behavior in Groups V-A and VI-A refractory metals: (1) By locating at the grain boundaries in the form of segregates of precipitates, promoting grain-boundary rupture and crack initiation; and (2) In solid solution by inhibiting dislocation movement and reducing the resistance to crack propagation. Both embrittling effects operate in Group VI-A metals; whereas, only the latter is significant in the Group V-A at the levels of purity currently achieved. The problem of reducing the low-temperature brittleness of Group V-A metals is readily solved through the purity route. Purification of Group V-A metals to interstitial levels well below the solubility limits may be readily accomplished either in the initial purification of the base metal or during melting or consolidation. There are three possible routes to solving the problem of the embrittling effect of interstitials on the Group VI-A metals: (1) the purity route, (2) through working, and (3) through alloying (thermodynamically through strong scavengers, by additions which modify the electron bonding, and via grain-refining dispersions). (Author).
Download or read book Hydrostatic Extrusion written by N. Inoue and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is intended to be a reference text on hydrostatic extru sion, a multidisciplinary technology involving the forming process of materials, tribology, high pressure engineering and so forth. Until now only one book bearing the title of hydrostatic extrusion, by Prof. Alexander and Dr. Lengyel, has been published since 1971. Although there are chapters on hydrostatic extrusion in such books as THE MECHANICAL BEHAVIOUR OF MATERIALS UNDER PRESSURE edited by Dr. Pugh, METAL FORMING by Prof. Avitzur and HIGH PRESSURE TECHNOLOGY by Drs. Spain and Paauwe, it is regrettable that no up~to-date reference books on hydro static extrusion are available. As is well known, hydrostatic extrusion is a nearly-ideal lubricated extrusion. Its advantages have been demonstrated by laboratory research in the past two decades, yet many manufacturers, however, still hesitate to adopt the technology in their plants. Their hesitation is certainly due to the lack of exact information on the process and its equipment and also to 'their unfamiliarity with the actual method of operation. In order to provide a useful introduction to the subject for engi neers who work in industries which plan to employ this technique and also to give exact and reliable information on the durability and perfo- ance of production facilities, as well as the capabilities of the process and the properties of extruded products, we decided to publish this book. Starting with theories and computational methods, the processes of cold, warm and hot hydrostatic extrusion are described by experts in their respective fields.
Download or read book Metallurgical Society Conferences written by and published by . This book was released on 1966 with total page 518 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Metallurgy for the Non Metallurgist Second Edition written by Arthur C. Reardon and published by ASM International. This book was released on 2011-01-01 with total page 527 pages. Available in PDF, EPUB and Kindle. Book excerpt: The completely revised Second Edition of Metallurgy for the Non-Metallurgist provides a solid understanding of the basic principles and current practices of metallurgy. This major new edition is for anyone who uses, makes, buys or tests metal products. For both beginners and others seeking a basic refresher, the new Second Edition of the popular Metallurgy for the Non-Metallurgist gives an all-new modern view on the basic principles and practices of metallurgy. This new edition is extensively updated with broader coverage of topics, new and improved illustrations, and more explanation of basic concepts. Why are cast irons so suitable for casting? Do some nonferrous alloys respond to heat treatment like steels? Why is corrosion so pernicious? These are questions that can be answered in this updated reference with many new illustrations, examples, and descriptions of basic metallurgy.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1970 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Technical Abstract Bulletin written by and published by . This book was released on with total page 908 pages. Available in PDF, EPUB and Kindle. Book excerpt:
