Download or read book Deformation and Fracture of Molybdenum Single Crystals written by Asif Abdul Khalig and published by . This book was released on 1964 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Rolled Molybdenum Single Crystals written by and published by . This book was released on 1964 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Deformation Twinning and Fracture in Molybdenum written by Francis Oscar Mueller and published by . This book was released on 1960 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Plastic Deformation of Molybdenum Single Crystals in Direct Shear written by James Luther Youngblood and published by . This book was released on 1963 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Effects of Impurities on the Plastic Deformation of Molybdenum Single Crystals written by Larry Don Whitmire and published by . This book was released on 1966 with total page 205 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Structural Alterations Accompanying the Deformation of Molybdenum Single Crystals in Compression written by John Henry Hoke and published by . This book was released on 1955 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Deformation of High Purity Four Percent Molybdenum Ferrite Single Crystals written by Maxwell Pevar and published by . This book was released on 1954 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Rolled Molybdenum Single Crystals written by Robert Blickensderfer and published by . This book was released on 1964 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Effect of Deformation on the Internal Friction of High purity Single Crystals of Molybdenum written by M. A. Abdelgadir and published by . This book was released on 1982 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effect of Surface Oxide Films on Deformation of Molybdenum Single Crystals written by Luis Fernández Martín and published by . This book was released on 1979 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dislocation Mobility and Plastic Deformation in Molybdenum Single Crystals written by Gauri Charan Das and published by . This book was released on 1967 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Deformation of Single Crystal Molybdenum at High Pressure written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Single crystal samples of micron dimensions oriented in the [001] direction were shortened 10 to 40% in uniaxial compression with superposed hydrostatic pressure to begin investigation of how the onset of yielding evolves with pressure. A testing machine based on opposed anvil geometry with precision pneumatic control of the applied force and capability to measure sub micron displacements was developed to produce shape changing deformation at pressure. The experiments extend observations of pressure dependent deformation to (almost equal to)5Gpa at shortening rates of (almost equal to)2*10−4. Samples have been recovered for post run characterization and analysis to determine if deformation mechanisms are altered by pressure. Experiments under hydrostatic pressure provide insight into the nature of materials under extreme conditions, and also provide a means for altering deformation behavior in a controlled fashion. The approach has a long history demonstrating that pressure enhances ductility in general, and produces enhanced hardening relative to that expected from normal cold work in the BCC metals Mo, Ta and Nb2. The pressure hardening is in excess of that predicted from the measured increase in shear modulus at pressure, and therefore is likely due to a dislocation mechanism, such as suppression of kink pair formation or the interaction of forest dislocation cores, and not from lattice resistance. The effect has not been observed in FCC metals, suggesting a fundamental difference between deformation mechanisms at pressure for the two classes. The purpose of this letter is to investigate the origin of pressure hardening with new experiments that extend the pressure range beyond 3 GPa, the upper limit of conventional large sample (1cm3) testing methods. Most previous high pressure deformation studies have been on poly crystals, relying on model dependent analysis to infer the maximum deviatoric stress that a deformed sample can support. In one experiment, a single crystal of the silicate olivine was compressed at 16 GPa with a sapphire uniaxial stress gage in the sample chamber. Splitting of the ruby fluorescence line increases with deviatoric stress, enabling direct measurement of the sample stress. Unfortunately, this method is not sensitive enough to determine first yielding of [001] single crystal Mo, and was not used in this study.

Download or read book Elastic plastic Deformation of Molybdenum Single Crystals Shocked to 12 5 GPa written by Anirban Mandal and published by . This book was released on 2016 with total page 181 pages. Available in PDF, EPUB and Kindle. Book excerpt: The observed orientation dependence of the elastic wave amplitudes was understood by examining the corresponding resolved shear stresses (tau) on {110} and {112} slip systems determined from quasi-static studies. A comparison of the resolved shear stresses (tau el) on the operative slip planes at the elastic limit and the reported Peierls stress (tauP) for screw dislocations in Mo suggested that elastic wave amplitudes attenuate rapidly for tau > tau P, but no measurable attenuation occurs after tau ~ tau P. Resolved shear stresses corresponding to elastic limits under shock loading were ~10--50 times larger than the shear stresses under quasi-static loading, a likely consequence of the large Peierls stress in Mo crystals.

Download or read book Investigation of the Relationship of Twinning to Brittle Fracture of Refractory Metals written by C. N. Reid and published by . This book was released on 1963 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first year's work on this program is reported. It is concluded that there is good evidence for brittle fracture induced by mechanical twinning in single crystals and polycrystalline Mo-C with grain sizes larger than 0.40 mm. However there is no evidence for such failures in Mo-C of grain size smaller than 0.25 mm, or in high-purity Cb. The effect of recrystallization texture on twinning is demonstrated, and the orientation dependence of twinning in Cb crystals is reported; a most unusual plastic instability is described in crystals of one orientation. It is shown that twinning in Mo-35Re occurs in bursts, which form in less than 2 mu sec; nucleation of twins occurs only at small strains but lateral growth takes place up to at least 12% strain.

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1971 with total page 1330 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Asymmetric Deformations of Molybdenum Single Crystals written by Silvanus Siu-Wai Lau and published by . This book was released on 1969 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dislocations and Mechanical Properties of Single Crystal Molybdenum Silicide written by Stuart Andrew Maloy and published by . This book was released on 1994 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dislocations and mechanical properties of single crystal MoSi2 have been investigated. Specimens were tested in compression along (001), (021), and (771) axes at strain rates of 1 × 10̄−4/s and 1 × 10−5/s and at temperatures ranging from 900-1600°C in vacuum or argon. The yield stress along (001) was an order of magnitude greater than that measured along (021) or (771) and along all orientations the yield stress was strongly dependent on temperature. Rate jump tests performed along (001) at 1400°C revealed that the yield stress was rate sensitive with a stress exponent of 4. The activated slip systems were determined using optical slip trace analyses and techniques in transmission electron microscopy. Slip occurred via five different slip systems (11100, 13100, 1001/2111, 131/2331, and 111/2111) depending on the orientation, temperature and strain rate at which each test was performed. The critical resolved shear stress was determined for the activated slip systems from the measured 0.2% yield stresses. At 900-1100°C, the lo west critical resolved shear stresses were for slip on the 11100, 1101/2111 and 131/2331 slip systems while at 1200-1600°C the lowest critical resolved shear stresses were for slip on the 11100 and the 13100 slip systems. Decompositions and dissociations of 1/2331 and 1/2111 dislocations were observed. The 1/2331 dislocation decomposes into 1/2111 and 110 dislocations during deformation at temperatures above 900°C. This decomposition prevents deformation by the 1/2331 dislocation at temperatures of 1200°C and above. HREM observations of the core of a 1/2331 dislocation revealed that it was dissociated out of the 13 glide plane after deformation at 900°C, while observations of the core of a 1/2111 dislocation after deformation at 1100°C revealed that it was dissociated by glide in the 110 plane. These core structures strongly affect the Peierls stress for glide of the 1/2331 and 1/2111 dislocations. Large climb dissociations of the 1/2111 and 1/2331 dislocations were also observed on the (001) plane, possibly resulting from the precipitation of Si vacancies on dislocations. A detailed comparison of these results with those of Umakoshi, Sakagami, Hirano and Yamane (1990) was undertaken by testing material provided by Umakoshi along (001) at 1000, 1300 and 1400°C and along (771) at 1100°C at a strain rate of 1 × 10−5/s . Marked differences were observed and explained by the dislocation substructure observed after deformation.