scholarly journals The Deformation and Shear Bands in the Fe–3%Si Alloy

1999 ◽  
Vol 32 (1-4) ◽  
pp. 21-39 ◽  
Author(s):  
B. K. Sokolov ◽  
V. V. Gubernatorov ◽  
I. V. Gervasyeva ◽  
A. K. Sbitnev ◽  
L. R. Vladimirov
Keyword(s):  
Single Crystals ◽  
Shear Bands ◽  
Fatigue Tests ◽  
Initial Orientation ◽  
Deformation Bands ◽  
Metallographic Study ◽  
Formation And Evolution

This paper deals with a metallographic study of shear and deformation bands, which are formed and developed during rolling and fatigue tests of single crystals and polycrystals of Fe–3% Si. The effect of the initial orientation of the single crystals, dimensions of grains in polycrystals, thickness of the samples and certain rolling factors on the formation of banded structures was analyzed. The effect of these structures on the structure and the texture, which appear in the deformed alloy subject to annealing, was studied too.The obtained data provided a better account of the banded structures and permitted directing ways to control their formation and evolution.

scholarly journals The Development of Dislocation Structure and Texture in Rolled Copper (001)[110] Single Crystals

1988 ◽  
Vol 10 (1) ◽  
pp. 67-75 ◽  
Author(s):  
M. Wróbel ◽  
S. Dymek ◽  
M. Blicharski ◽  
S. Gorczyca
Keyword(s):  
Electron Microscopy ◽  
Single Crystals ◽  
Dislocation Structure ◽  
Transverse Direction ◽  
Shear Bands ◽  
Taylor Factor ◽  
Initial Orientation ◽  
Slip Systems ◽  
Deformation Bands ◽  
Pole Figures

The initial orientation has split into two equally strong symmetric orientations: (112)[111¯] and (112)[1¯1¯1]. Areas of identical orientation were band shaped and were called deformation bands. Up to 60% reduction, deformation occurs by slip on one plane (one from two possible) in two directions. This leads to the appearance of deformation bands with transition bands between them. Due to such deformation the initial orientation rotates around transverse direction towards the end-orientation {112}〈111〉. Due to rotation of the crystallographic lattice with deformation, the Taylor factor M changes as well, and it causes the activation of two not coplanar slip systems which stabilize the end-orientations {112}〈111〉. Such a sequence of the slip systems activation was concluded from the agreement of the calculated and experimental pole figures. The electron microscopy investigations showed that first shear bands formed due to the activation of these new slip systems.

The Effect of the Initial Orientation on Microstructure Development of Copper Single Crystals Subjected to Equal-Channel Angular Pressing

2006 ◽  
Vol 503-504 ◽  
pp. 799-804 ◽  
Author(s):  
Hiroyuki Miyamoto ◽  
J. Fushimi ◽  
Takura Mimaki ◽  
Alexei Vinogradov ◽  
Satoshi Hashimoto
Keyword(s):  
Single Crystals ◽  
Equal Channel Angular Pressing ◽  
Crystallographic Orientation ◽  
Shear Bands ◽  
Initial Orientation ◽  
Processing Route ◽  
Microstructure Development ◽  
Angular Pressing ◽  
Copper Single Crystals ◽  
Heterogeneous Deformation

Copper single crystals were subjected to equal-channel angular pressing (ECAP) via the so-called route A and Bc, in order to examine the influence of initial crystallographic orientation and processing route on microstructure development and grain fragmentation. Microstructural changes were examined by transmission electron microscopy (TEM). The pressing via the route Bc resulted in finer microstructure for all orientations in terms of grain size, equiaxiality and orientation scattering after four passes. Effect of initial crystallographic orientation on the grain refinement was also recognized, and it might be attributed to heterogeneous deformation such as shear bands, whose formation is strongly orientation dependent. After eight passes, however, the effect of processing route and initial orientation cannot be recognized.

On the formation of deformation bands in fatigued copper single crystals

2002 ◽  
Vol 82 (16) ◽  
pp. 3129-3147 ◽  
Author(s):  
S. X. Li ◽  
X. W. Li ◽  
Z. F. Zhang ◽  
Z. G. Wang ◽  
K. Lu
Keyword(s):  
Single Crystals ◽  
Deformation Bands ◽  
Copper Single Crystals

Anthracene fluorescence at low temperatures. I. Purified single crystals

1972 ◽  
Vol 25 (7) ◽  
pp. 1411 ◽  
Author(s):  
LE Lyons ◽  
LJ Warren
Keyword(s):  
Low Temperature ◽  
Single Crystals ◽  
Fluorescence Spectrum ◽  
Low Temperatures ◽  
Free Exciton ◽  
Deformation Bands ◽  
Exciton Emission ◽  
Polarized Emission ◽  
Impurity Bands ◽  
Phonon Structure

The low-temperature fluorescence spectrum of purified vapour-grown anthracene single crystals is presented and the free-exciton emission distinguished from a number of defect or impurity bands present even in the purest crystals. In assigning the observed bands the symmetry of the active vibrations and the origin of background fluorescence and deformation bands are discussed. The phonon structure in the region of the fluorescence origin was found to be almost completely b-polarized. Emission of electronic origin (25103 cm-1) was too weak to be observed. Polarization ratios of the principal vibronio bands at 5.6 K are given.

The Formation of New Orientations during Recrystallization of Silver Single Crystals with {112} Initial Orientation

2004 ◽  
Vol 467-470 ◽  
pp. 177-182 ◽  
Author(s):  
Henryk Paul ◽  
Julian H. Driver ◽  
Claire Maurice ◽  
Andrzej Piątkowski
Keyword(s):  
Single Crystals ◽  
High Purity ◽  
Decisive Role ◽  
Simple Relation ◽  
Initial Orientation ◽  
Local Orientation ◽  
Isolated Nuclei ◽  
Cube Orientation ◽  
Early Stages

The recrystallization mechanisms in high purity Ag crystals with C{112}<111> initial orientation, deformed by channel-die compression, have been studied by local orientation measurements using TEM and SEM/EBSD. The microtexture analysis clearly indicates the importance of a simple relation of 25-40o (<111> or <112>) type, which is frequently observed during the early stages of recrystallization between isolated nuclei of uniform orientation and one of the as-deformed groups of components. As recrystallization proceeds, recrystallization twinning increases radically. In C-oriented silver single crystals this latter mechanism also plays a decisive role in the formation of the cube orientation.

scholarly journals Distribution, microphysical properties, and tectonic controls of deformation bands in the Miocene subduction wedge (Whakataki Formation) of the Hikurangi subduction zone

Solid Earth ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 141-170
Author(s):  
Kathryn E. Elphick ◽  
Craig R. Sloss ◽  
Klaus Regenauer-Lieb ◽  
Christoph E. Schrank
Keyword(s):  
Microstructural Analysis ◽  
Shear Bands ◽  
Normal Faults ◽  
Pore Collapse ◽  
Deformation Bands ◽  
Progressive Deformation ◽  
Compaction Bands ◽  
Microphysical Properties ◽  
Sealing Capacity ◽  
Grain Crushing

Abstract. We analyse deformation bands related to horizontal contraction with an intermittent period of horizontal extension in Miocene turbidites of the Whakataki Formation south of Castlepoint, Wairarapa, North Island, New Zealand. In the Whakataki Formation, three sets of cataclastic deformation bands are identified: (1) normal-sense compactional shear bands (CSBs), (2) reverse-sense CSBs, and (3) reverse-sense shear-enhanced compaction bands (SECBs). During extension, CSBs are associated with normal faults. When propagating through clay-rich interbeds, extensional bands are characterised by clay smear and grain size reduction. During contraction, sandstone-dominated sequences host SECBs, and rare CSBs, that are generally distributed in pervasive patterns. A quantitative spacing analysis shows that most outcrops are characterised by mixed spatial distributions of deformation bands, interpreted as a consequence of overprint due to progressive deformation or distinct multiple generations of deformation bands from different deformation phases. As many deformation bands are parallel to adjacent juvenile normal faults and reverse faults, bands are likely precursors to faults. With progressive deformation, the linkage of distributed deformation bands across sedimentary beds occurs to form through-going faults. During this process, bands associated with the wall-, tip-, and interaction-damage zones overprint earlier distributions resulting in complex spatial patterns. Regularly spaced bands are pervasively distributed when far away from faults. Microstructural analysis shows that all deformation bands form by inelastic pore collapse and grain crushing with an absolute reduction in porosity relative to the host rock between 5 % and 14 %. Hence, deformation bands likely act as fluid flow barriers. Faults and their associated damage zones exhibit a spacing of 9 m on the scale of 10 km and are more commonly observed in areas characterised by higher mudstone-to-sandstone ratios. As a result, extensive clay smear is common in these faults, enhancing the sealing capacity of faults. Therefore, the formation of deformation bands and faults leads to progressive flow compartmentalisation from the scale of 9 m down to about 10 cm – the typical spacing of distributed, regularly spaced deformation bands.

Fatigue-induced shear bands in ferritic single crystals

1982 ◽  
Vol 30 (1) ◽  
pp. 273-278 ◽  
Author(s):  
T. Magnin ◽  
A. Fourdeux ◽  
J.H. Driver
Keyword(s):  
Single Crystals ◽  
Shear Bands
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