scholarly journals Dislocation Creep of Olivine and Amphibole in Amphibole Peridotites from Åheim, Norway

Minerals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1018
Author(s):  
Sejin Jung ◽  
Takafumi Yamamoto ◽  
Jun-ichi Ando ◽  
Haemyeong Jung
Keyword(s):  
Electron Microscopy ◽  
Slip System ◽  
Electron Backscatter Diffraction ◽  
Microstructural Analysis ◽  
Dislocation Creep ◽  
Transmission Electron ◽  
Electron Backscatter ◽  
Different Types ◽  
Localized Shear Deformation ◽  
Backscatter Diffraction

Amphibole peridotite samples from Åheim, Norway, were analyzed to understand the deformation mechanism and microstructural evolution of olivine and amphibole through the Scandian Orogeny and subsequent exhumation process. Three Åheim amphibole peridotite samples were selected for detailed microstructural analysis. The Åheim amphibole peridotites exhibit porphyroclastic texture, abundant subgrain boundaries in olivine, and the evidence of localized shear deformation in the tremolite-rich layer. Two different types of olivine lattice preferred orientations (LPOs) were observed: B- and A-type LPOs. Electron backscatter diffraction (EBSD) mapping and transmission electron microscopy (TEM) observations revealed that most subgrain boundaries in olivine consist of dislocations with a (001)[100] slip system. The subgrain boundaries in olivine may have resulted from the deformation of olivine with moderate water content. In addition, TEM observations using a thickness-fringe method showed that the free dislocations of olivine with the (010)[100] slip system were dominant in the peridotites. Our data suggest that the subgrain boundaries and free dislocations in olivine represent a product of later-stage deformation associated with the exhumation process. EBSD mapping of the tremolite-rich layer revealed intracrystalline plasticity in amphibole, which can be interpreted as the activation of the (100)[001] slip system.

Where are the geometrically necessary dislocations accommodating small imprints?

2009 ◽  
Vol 24 (3) ◽  
pp. 647-651 ◽  
Author(s):  
M. Rester ◽  
C. Motz ◽  
R. Pippan
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Twin Boundary ◽  
Crystal Orientation ◽  
Electron Backscatter Diffraction ◽  
Transmission Electron ◽  
Electron Backscatter ◽  
Copper Single Crystals ◽  
Backscatter Diffraction ◽  
Small Misorientation

Electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM) analyses of small indentations in copper single crystals exhibit only slight changes of the crystal orientation in the surroundings of the imprints. Far-reaching dislocations might be the reason for these small misorientation changes. Using EBSD and TEM technique, this work makes an attempt to visualize the far-propagating dislocations by introducing a twin boundary in the vicinity of small indentations. Because dislocations piled up at the twin boundary produce a misorientation gradient, the otherwise far-propagating dislocations can be detected.

scholarly journals Evolution Of Precipitate Morphology During Extrusion In Mg ZK60A Alloy

2015 ◽  
Vol 60 (2) ◽  
pp. 1423-1426 ◽  
Author(s):  
J. Park ◽  
K.H. Jung ◽  
G.A. Lee ◽  
M. Kawasaki ◽  
B. Ahn
Keyword(s):  
Electron Backscatter Diffraction ◽  
Microstructural Analysis ◽  
Extrusion Process ◽  
Formation Mechanisms ◽  
Precipitate Morphology ◽  
X Ray ◽  
Transmission Electron ◽  
Electron Backscatter ◽  
Backscatter Diffraction ◽  
Evolution Of Precipitates

Abstract In this study, a continuously casted ZK60A magnesium alloy (Mg-Zn-Zr) was extruded in two different extrusion ratios, 6:1 and 10:1. The evolution of precipitates was investigated on the two extruded materials and compared with that of as-casted material. The microstructural analysis was performed by electron backscatter diffraction and transmission electron microscopy, and the compositional information was obtained using energy-dispersive X-ray spectroscopy. Several distinct morphologies of precipitates were observed, such as dot, rod, and disk shaped. The formation mechanisms of those precipitates were discussed with respect to the heat and strain during the extrusion process.

scholarly journals Texture and Microtexture of Pure (6N) and Commercially Pure Aluminum after Deformation by Extrusion with Forward-Backward Rotating Die (Kobo)

2016 ◽  
Vol 61 (1) ◽  
pp. 461-468 ◽  
Author(s):  
M. Bieda ◽  
S. Boczkal ◽  
P. Koprowski ◽  
K. Sztwiertnia ◽  
K. Pieła
Keyword(s):  
Electron Microscopy ◽  
Grain Size ◽  
Electron Backscatter Diffraction ◽  
Pure Aluminum ◽  
Pure Aluminium ◽  
Commercially Pure ◽  
Transmission Electron ◽  
Electron Backscatter ◽  
Backscatter Diffraction ◽  
Crystallographic Orientations

Pure aluminium (6N) and commercially pure aluminium (99.7) was deformed by KOBO method. Microstructure and texture of both materials after deformation was analyzed by means of scanning and transmission electron microscopy. Advanced methods of crystallographic orientations measurements like Electron Backscatter Diffraction - EBSD (SEM) and microdiffraction (TEM) was used. Grain size distribution and misorientation between grains in cross and longitudinal sections of the samples were analyzed. Differences in size and homogeneity of the grains were observed in both materials. Pure aluminium was characterized by larger grain size in both sections of extruded material. Whereas commercially pure aluminium reveals smaller grain size and more homogeneous and stable microstructure.

Scanning Electron Microscopy and Transmitted Electron Backscatter Diffraction Examination of Asbestos Standard Reference Materials, Amphibole Particles of Differing Morphology, and Particle Phase Discrimination from Talc Ores

2014 ◽  
Vol 20 (6) ◽  
pp. 1805-1816 ◽  
Author(s):  
Bryan R. Bandli ◽  
Mickey E. Gunter
Keyword(s):  
Electron Microscopy ◽  
Analytical Methods ◽  
Electron Backscatter Diffraction ◽  
Health And Safety ◽  
Crystal Form ◽  
Standard Reference Materials ◽  
Transmission Electron ◽  
Electron Backscatter ◽  
Diffraction Patterns ◽  
Backscatter Diffraction

AbstractSince 1972, when the US Occupational Health and Safety Administration established the first limits on occupational exposure to asbestos fibers, numerous analytical methods employing several microscopy techniques have been developed to identify a group of minerals defined by legislation as asbestos. While transmission electron microscopy (TEM) is implemented in standardized analytical methods, these methods specify the use of selected area electron diffraction. Because of this constraint, the diffraction data a TEM can provide are often underutilized due to challenges associated with collecting and interpreting individual diffraction patterns. It has been shown that transmission electron backscatter diffraction (tEBSD) produces diffraction patterns nearly identical to electron backscatter diffraction, but from smaller crystal domains. This paper explores the utility of tEBSD for characterization of asbestiform particles from reference asbestos materials, a suite of amphibole minerals of varying morphologies to determine if there is a correlation between mineral habit (i.e., crystal form), microscopic particle shape preferred orientation, and mineral specimens from an industrial talc deposit to provide a case study of the utility and limitations of the technique.

Heteroepitaxial CVD Growth of 3C-SiC on Diamond Substrate

2014 ◽  
Vol 778-780 ◽  
pp. 226-229 ◽  
Author(s):  
Véronique Soulière ◽  
Arthur Vo-Ha ◽  
Davy Carole ◽  
Alexandre Tallaire ◽  
Ovidiu Brinza ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Backscatter Diffraction ◽  
Heteroepitaxial Growth ◽  
Silicon Deposition ◽  
Transmission Electron ◽  
Diamond Substrate ◽  
Electron Backscatter ◽  
Cvd Growth ◽  
Backscatter Diffraction

This work presents the successful CVD heteroepitaxial growth of 3C-SiC on diamond (100) substrates. When performing a direct SiC growth at 1500°C on such substrate, it leads to polycrystalline deposit. The use of a substrate pretreatment involving silicon deposition allows forming a more continuous and smoother layer. Electron BackScatter Diffraction and Transmission Electron Microscopy all revealed that the 3C-SiC layer grown on the (100) diamond substrate is monocrystalline and well oriented.

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