Download or read book Surface and Interfacial Effects in Relation to Brittleness in Refractory Metals written by A. Fourdeux and published by . This book was released on 1966 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental program was conducted to compare the mechanical properties of high purity and impure niobium and the mechanical properties of high purity tungsten, both in polycrystalline and single crystal forms. Slip in high purity niobium takes place on the (110) planes in the (111) directions and yielding is governed by the conservative motion of jogs in screw dislocations, rather than by the unlocking of dislocations from the interstitial impurity cloud. Between the upper and lower yield points there is a sudden generation of a large number of dislocations by double cross-slip mechanism. High purity niobium has greater ductility, higher uniform elongation, increased work hardening, but lower strength than impure niobium. Further, it has a yield point in the temperature range 20 C to 800 C. Appreciable ductility can be achieved at room temperature in commercially pure tungsten, but the mechanical properties are strongly orientation dependent. The ductile-to-brittle transition temperature is about 100 C higher sintered material than in melted material which is of coarser gran size and probably higher purity. Very high purity polycrystalline tungsten was found to show some ductility down to -196 C in the recrystallization condition. However, the fracture process is controlled to a considerable extent by grain boundaries in the temperature range +200 C to -196 C. (Author).
Download or read book Technical Abstract Bulletin written by and published by . This book was released on with total page 776 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ductile brittle Transition in the Refractory Metals written by F. R. Schwartzberg and published by . This book was released on 1959 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effect of Impurities and Temperature on the Interfacial Free Energies and Surface Diffusion of Refractory Metals written by B. C. Allen and published by . This book was released on 1972 with total page 65 pages. Available in PDF, EPUB and Kindle. Book excerpt: The average surface free energies of chromium, molybdenum, and tungsten have been measured at 0.6 to 0.8 of the absolute melting temperature by multiphase equilibrations with liquid tin or silver in tantalum-gettered argon. With grain boundary groove angles measured by interferometry and stylus profile tracing, the respective values were found. (Author).
Download or read book Properties of Refractory Metals written by Walter D. Wilkinson and published by . This book was released on 1969 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Techniques of Metals Research Techniques involving extreme environment nondestructive techniques computer methods in metals research and data analysis Editor R F Bunshah 2 v written by Rointan Framroze Bunshah and published by . This book was released on 1968 with total page 864 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 Techniques of Metals Research Techniques for the direct observation of structure and imperfections Editor R F Bunshah 2 v written by Rointan Framroze Bunshah and published by . This book was released on 1968 with total page 872 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 1995 with total page 702 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 1975-03 with total page 988 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Abstracts of AF Materials Laboratory Reports July 1965 June 1966 written by Air Force Materials Laboratory (U.S.). Research and Technology Division and published by . This book was released on 1967 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy Research Abstracts written by and published by . This book was released on 1993-12 with total page 526 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Comprehensive Structural Integrity written by Ian Milne and published by Elsevier. This book was released on 2003-07-25 with total page 4647 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of this major reference work is to provide a first point of entry to the literature for the researchers in any field relating to structural integrity in the form of a definitive research/reference tool which links the various sub-disciplines that comprise the whole of structural integrity. Special emphasis will be given to the interaction between mechanics and materials and structural integrity applications. Because of the interdisciplinary and applied nature of the work, it will be of interest to mechanical engineers and materials scientists from both academic and industrial backgrounds including bioengineering, interface engineering and nanotechnology. The scope of this work encompasses, but is not restricted to: fracture mechanics, fatigue, creep, materials, dynamics, environmental degradation, numerical methods, failure mechanisms and damage mechanics, interfacial fracture and nano-technology, structural analysis, surface behaviour and heart valves. The structures under consideration include: pressure vessels and piping, off-shore structures, gas installations and pipelines, chemical plants, aircraft, railways, bridges, plates and shells, electronic circuits, interfaces, nanotechnology, artificial organs, biomaterial prostheses, cast structures, mining... and more. Case studies will form an integral part of the work.
Download or read book Metals Abstracts written by and published by . This book was released on 1995 with total page 662 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aerospace Structural Metals Handbook written by and published by . This book was released on 1989 with total page 828 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book International Aerospace Abstracts written by and published by . This book was released on 1996 with total page 1012 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Structure and Properties of Engineering Materials written by Robert Maynard Brick and published by McGraw-Hill Science, Engineering & Mathematics. This book was released on 1977 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt:
