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 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 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 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 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 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:
Download or read book Fourth Status Report of the U S Government Metalworking Processes and Equipment Program written by F. C. Holden and published by . This book was released on 1965 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Refractory Metals and Alloys written by and published by . This book was released on 1963 with total page 466 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Refractory Metals and Alloys II written by M. Semchyshen and published by . This book was released on 1963 with total page 468 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Annual Report High Temperature Materials and Reactor Component Development Programs written by and published by . This book was released on 1964-02-28 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Journal of the Institute of Metals written by Institute of Metals and published by . This book was released on 1966 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt:
