Download or read book High Strain Rate Effects in Tungsten Quasi single Crystals written by Robert William Crafts and published by . This book was released on 1992 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The High Strain Rate Deformation of Tungsten Single Crystals written by and published by . This book was released on 1994 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt: Samples of single-crystal tungsten, in three orientations (100, 110, 111), were compressively deformed at high strain rates (1,000-2,000 /s) using a Kolsky (split-Hopkinson) type pressure bar apparatus. Samples of the single-crystal tungsten were also deformed at low strain rate (0.0001/ s) using a conventional load frame. The 110 orientation exhibited constraint of flow consistent with twofold crystal symmetry about this axis, resulting in skewed flow and noncylindrical specimens after the Kolsky bar test. Both the 111 and 110 orientations exhibited a yield or load drop phenomenon. This load drop may have been associated with either: (1) lack of screw dislocation cross slip at high strain rate; (2) twinning of the crystal lattice; or (3)interstitial solute atoms such as nitrogen or carbon pinning dislocations. As a result of this load drop for the lower symmetry 111 and 110 orientations, the quasi-static (0.0001/s) test had higher flow stress for a given strain than the higher strain rate tests with the Kolsky bar. The 100 orientation crystals exhibited uniform deformation and high rate of work-hardening at both low and high strain rates. The unique behavior of these crystals is postulated in terms of the crystal symmetry, structural evolution at various strain rates, and dislocation flow mechanisms.
Download or read book Deformation Mechanisms in Tungsten Single Crystals in Ballistic Impact Experiments written by and published by . This book was released on 1993 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: The performance of tungsten single crystals in ballistic impact varies strongly as a function of crystallographic orientation. The deformation structure of recovered single crystal rods fired in ballistic environments has been characterized by optical microscopy, SEM and TEM, and x-ray diffraction. The observed microstructures are varied and provide substantial insights into the factors governing the penetration and flow behavior under ballistic conditions. Crystallographic orientation influences the potential for developing shear which enhances mat flow, and this enhancement ultimately maximizes the energy available for target penetration. Microstructural analysis elucidates the various mechanisms occuring during the flow process for single crystals of high- symmetry orientations, and suggests possible analogies between the penetration behavior of the tungsten single crystals and other materials ... Crystallography, Strain rate, Dislocations, Mass transfer, Shear stresses.
Download or read book Masters Theses in the Pure and Applied Sciences written by Wade H. Shafer and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 426 pages. Available in PDF, EPUB and Kindle. Book excerpt: Masters Theses in the Pure and Applied Sciences was first conceived, published, and disseminated by the Center for Information and Numerical Data Analysis and Synthesis (CINDAS)* at Purdue University in 1957, starting its coverage of theses with the academic year 1955. Beginning with Volume 13, the printing and dis semination phases of the activity were transferred to University Microfilms/Xerox of Ann Arbor, Michigan, with the thought that such an arrangement would be more beneficial to the academic and general scientific and technical community. After five years of this joint undertaking we had concluded that it was in the interest of all concerned if the printing and distribution of the volumes were handled by an international publishing house to assure improved service and broader dissemination. Hence, starting with Volume 18, Masters Theses in the Pure and Applied Sciences has been disseminated on a worldwide basis by Plenum Publishing Corporation of New York, and in the same year the coverage was broadened to include Canadian universities. All back issues can also be ordered from Plenum. We have reported in Volume 38 (thesis year 1993) a total of 13,787 thesis titles from 22 Canadian and 164 United States universities. We are sure that this broader base for these titles reported will greatly enhance the value of this impor tant annual reference work. While Volume 38 reports theses submitted in 1993, on occasion, certain uni versities do report theses submitted in previous years but not reported at the time.
Download or read book Dislocation Structures in Single Crystal Tungsten and Tungsten Alloys written by Joseph R. Stephens and published by . This book was released on 1969 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effect of Strain Rate on Mechanical Properties of Wrought Sintered Tungsten at Temperatures Aboue 2500 Degrees F written by Paul F. Sikora and published by . This book was released on 1961 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Physical Metallurgy of Tungsten and Tungsten Alloys written by Westinghouse Electric Corporation. Westinghouse Lamp Division and published by . This book was released on 1962 with total page 458 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 Flow Stress Strain Hardening Rate and Dislocation Avalanches Size and Strain Rate Dependence in Nano and Micro scaled Single Crystal Tungsten written by Katherine Jiang and published by . This book was released on 2019 with total page 41 pages. Available in PDF, EPUB and Kindle. Book excerpt: The plastic behavior of body centered cubic metals generally exhibits strong strain rate and size dependence, attributed to the mobility of dislocations and availability of dislocation sources. Through in situ scanning electron microscope nano-compression testing on room temperature Tungsten single crystal micro- and nano- pillars with diameters ranging from 2000 nm to 100 nm, this work demonstrates the coupled effect of size and strain rate on plastic flow behavior. It is found that strain rate sensitivity of flow stress decreases with decreasing size, with 100 nm pillars showing negative strain rate sensitivity. Accordingly, the size effect decreases with increasing strain rate. In addition, the strain hardening rate demonstrates strong size dependence and statistically insignificant strain rate dependence, increasing with more scatter at different strain rate as size decreases. We further show the influence of size and strain rate on pillar morphology, where smaller pillars and lower strain rates are dominated by localized plastic deformation.
Download or read book Discontinuously Reinforced Titanium Matrix Composites written by Lujun Huang and published by Springer. This book was released on 2017-04-21 with total page 181 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces readers to titanium matrix composites (TMCs) with novel network microstructures. The bottleneck problem of extreme brittleness and low strengthening effect surrounding TMCs fabricated by means of powder metallurgy has recently been solved by designing network microstructures, which yield both high strength and superior ductility. As such, network structured TMCs will increasingly offer materials characterized by low weight, high strength, high temperature resistance and superior deformability. The book systematically addresses the design, fabrication, microstructure, properties, modification, and toughening mechanisms of these composites, which will help us find innovative solutions to a range of current and future engineering problems.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 652 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Download or read book Effect of Orientation on Ductile to Brittle Transition of Tungsten Single Crystals written by Ralph G. Garlick and published by . This book was released on 1966 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Metallurgical Effects at High Strain Rates written by R. Rohde and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 696 pages. Available in PDF, EPUB and Kindle. Book excerpt: A conference on Metallurgical Effects at High Strain Rates was held at Albuquerque, New Mexico, February 5 through 8, 1973, under joint sponsorship of Sandia Laboratories and the Physical Metallurgy Committee of The Metallurgical Society of AIME. This book presents the written proceedings of the meeting. The purpose of the conference was to gather scientists from diverse disciplines and stimulate interdisciplinary discussions on key areas of materials response at high strain rates. In this spirit, it was similar to one of the first highly successful con ferences on this subject held in 1960, in Estes Park, Colorado, on The Response of Metals to High Velocity Deformation. The 1973 conference was able to demonstrate rather directly the increased understanding of high strain rate effects in metals that has evolved over a period of roughly 12 years. In keeping with the interdisciplinary nature of the meeting, the first day was devoted to a tutorial session of invited papers to provide attendees of diverse backgrounds with a common basis of understanding. Sessions were then held with themes centered around key areas of the high strain rate behavior of metals.
Download or read book High Strain Rate Behavior of Refractory Metals and Alloys written by Minerals, Metals and Materials Society. Fall Meeting and published by Minerals, Metals, & Materials Society. This book was released on 1992 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt: This aims to be the most complete volume available on the developing technology of refractory metals and alloys for high strain rate applications. Processing, testing and evaluation procedures for this group of specialized materials are thoroughly examined. Added emphasis is placed on high strain rate processing, dynamic compaction and forging, microstructure, texture, composition and loading rate effects on deformation and fracture.
Download or read book Dislocations and Plastic Flow in Crystals written by A. H. Cottrell and published by . This book was released on 1953 with total page 223 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Masters Theses in the Pure and Applied Sciences written by Sade H Shafer and published by Springer Science & Business Media. This book was released on 1995 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cited in Sheehy, Chen, and Hurt . Volume 38 (thesis year 1993) reports a total of 13,787 thesis titles from 22 Canadian and 164 US universities. As in previous volumes, thesis titles are arranged by discipline and by university within each discipline. Any accredited university or college with a grad
Download or read book Strain Rate Effects in Alpha iron Single Crystals written by Dean Reese Heerwagen and published by . This book was released on 1966 with total page 78 pages. Available in PDF, EPUB and Kindle. Book excerpt:
