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.
Download or read book Dislocations and Mechanical Properties of Single Crystal Niobium Disilicide written by and published by . This book was released on 1996 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: The mechanical properties of single crystal NbSi2 have been investigated along [0001] and 45° from [0001] toward [11{bar 2}0] using a Nikon QM-2 hot hardness tester from room temperature to 900 C in vacuum. The hardness along [0001] increases from room temperature to 300 C followed by a sharp decrease in hardness with temperature which is accompanied by a large uplift observed surrounding the indentations. Dislocations surrounding the indentations at room temperature and 300 C were analyzed using techniques in transmission electron microscopy to find slip by 10{bar 1}0 dislocations at room temperature with a change in the active slip systems at 300 C. The hardness along a direction 45° from [0001] toward [11{bar 2}0] sharply decreases with increasing temperature above room temperature. Coarse slip lines surround the indentations referring to slip on the basal plane.
Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1976 with total page 680 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mechanical Properties and Temperature of Recrystallization of Single Crystals of Molybdenum written by E. M. Savitskiy and published by . This book was released on 1963 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dislocations and Mechanical Properties of Crystals written by United States. Air Force. Office of Scientific Research and published by . This book was released on 1957 with total page 746 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dislocation Dynamics and Mechanical Properties of Crystals written by Edward Nadgornyi and published by Elsevier Science & Technology. This book was released on 1988 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dislocations in Solids written by Hiroshi Suzuki and published by CRC Press. This book was released on 2023-03-08 with total page 691 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume comprises the Proceedings of the Yamada Conference IX on Dislocations in Solids, held in August 1984 in Tokyo. The purpose of the conference was two-fold: firstly to evaluate the increasing data on basic properties of dislocations and their interaction with other types of defects in solids and, secondly, to increase understanding of the material properties brought about by dislocation-related phenomena. Metals and alloys, semi-conductors and ions crystals were discussed. One of the important points of contention was the electronic state at the core of dislocation. Another was the dislocation model of amorphous structure.
Download or read book Dislocations in Metals written by American Institute of Mining and Metallurgical Engineers. Institute of Metals Division and published by . This book was released on 1954 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Crystal Dislocations Their Impact on Physical Properties of Crystals written by Peter Lagerlof and published by . This book was released on 2018 with total page 1 pages. Available in PDF, EPUB and Kindle. Book excerpt: The proposed existence of the edge and screw dislocation in the 1930s, and the subsequent work showing that dislocation theory could explain the plastic deformation of crystals, represent an important step in developing our understanding of materials into a science. The continued work involved with characterization of dislocations and linking them to a variety of physical properties in both single and poly crystals have made enormous progress over the past 50 years. It is rare to find a technical application involving a material with any crystal structure that is not impacted by dislocations; mechanical properties, massive phase transformations, interphases, crystal growth, electronic properties, the list goes on. In many systems the properties is controlled by the formation of partial dislocations separated by a stacking fault; for example plastic deformation via deformation twinning. And finally, giant strides have been made in characterization and modeling of systems containing dislocations. The Special Issue on “Crystal Dislocations” is intended to provide a unique international forum aimed at covering a broad range of results involving dislocations and their importance on crystal properties and crystal growth. Scientists working in a wide range of disciplines are invited to contribute to this cause.Dr. K. Peter D. Lagerlof, Associate Professor of CeramicsGuest Editor
Download or read book Dislocations and mechanical properties written by Melvin A. Wilkov and published by . This book was released on 1964 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dislocations and Mechanical Properties of Crystals written by and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Molybdenum Silicide Formation on Single Crystal Polycrystalline and Amorphous Silicon written by Charles Michael Doland and published by . This book was released on 1988 with total page 556 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dislocation Interaction and the High Temperature Mechanical Properties of MgO Crystals written by Roger Chang and published by . This book was released on 1960 with total page 24 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 1987 with total page 952 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dislocations and Properties of Real Materials written by Metals Society. Metal Science Committee and published by Ashgate Publishing. This book was released on 1985 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dislocations and Mechanical Properties of Crystals written by D.J. Fisher and published by . This book was released on 1957 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dislocations and Mechanical Properties of Crystals written by États-Unis. Air Force. Office of Scientific Research and published by . This book was released on 1957 with total page 634 pages. Available in PDF, EPUB and Kindle. Book excerpt:
