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.

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 A Microstructure Investigation of the Deformation and Recrystallization of Particle-Containing Aluminium-Silicon Alloys

1993 ◽  
Vol 20 (1-4) ◽  
pp. 125-140 ◽  
Author(s):  
F. Habiby ◽  
F. J. Humphreys
Keyword(s):  
Single Crystals ◽  
Recrystallization Texture ◽  
Rolling Texture ◽  
Plasticity Theory ◽  
Second Phase ◽  
Slip Systems ◽  
Deformation Bands ◽  
Silicon Alloys ◽  
X Ray ◽  
Second Phase Particles

Single crystals and polycrystals of aluminium containing non-deformable second-phase particles of silicon, have been deformed, and the resultant structures investigated by microscopy and by X-ray and microtexture techniques. The particle size is found to influence the scale of the deformation bands formed, and there is evidence that particles may affect the nucleation of these bands. The deformed materials were recrystallized, and the effect of particle stimulated nucleation on the weakening of the rolling texture is discussed with reference to a computer simulation. In contrast, the recrystallization texture of particle-containing single crystals deformed on only two slip systems is sharp, and it is shown that the texture components are consistent with plasticity theory.

Shear Banding in Twinned Structures and Their Influence on Brass-Type Texture

2005 ◽  
Vol 495-497 ◽  
pp. 1067-1072
Author(s):  
Henryk Paul ◽  
Adam Morawiec ◽  
Emmanuel Bouzy ◽  
Jean-Jacques Fundenberger ◽  
Andrzej Piątkowski
Keyword(s):  
Electron Microscopy ◽  
Shear Banding ◽  
Pure Copper ◽  
Shear Bands ◽  
Deformation Mode ◽  
Lattice Rotation ◽  
Slip Systems ◽  
Transmission Electron ◽  
Plane Strain Deformation ◽  
Orientation Maps

The local crystallography within shear bands (SB) has been examined in a single crystal of {112}<111> orientation of pure copper deformed at 77K by channel-die compression to strains of about 1. Setting up a system for making high-resolution orientation maps using transmission electron microscopy (TEM) has opened new advantageous circumstances for the analysis of orientation changes within SB. This method with spatial resolution higher than 10nm allows the examination of microstructure images composed of nanoscale subcells forming SB. It has been found that for well-developed shear bands, a crystal lattice rotation about <112> direction tends to dominate and this process is usually accompanied by activation of new slip systems. The present work shows that despite the plane strain deformation mode, the mechanism of lattice rotation within emerging SBs may lead to Goss and Brass texture components.

scholarly journals Texture and Hardness in Wire Drawn [001] Copper Single Crystals

1998 ◽  
Vol 31 (1-2) ◽  
pp. 1-19 ◽  
Author(s):  
A. Borbély ◽  
L. S. Tóth ◽  
B. Bolle
Keyword(s):  
Single Crystals ◽  
Vickers Hardness ◽  
Wire Drawing ◽  
Plasticity Model ◽  
Deformation Bands ◽  
Crystal Plasticity Model ◽  
Pole Figures ◽  
Type Rate ◽  
Copper Single Crystals ◽  
Measured Hardness

The crystallographic texture and Vickers hardness which develop during wire-drawing of [001] oriented copper single crystals have been studied experimentally as well by simulations. The experiments revealed orientation changes producing cross-shaped patterns in the {200} pole figures and important variations in the Vickers hardness across the diameter. Metallographic investigations showed the presence of deformation bands perpendicular to the initial 〈100〉 directions. By adopting a model for the velocity field inside the die, simulations have been carried out by using a Taylor type rate sensitive crystal plasticity model, including microscopic hardening. The simulated pole figures show the features of the experimental ones and the predicted stress levels correlate well with the measured hardness data.

scholarly journals Texture Evolution and Anisotropy of Plastic Flow in Hot Compression of Extruded ZK60-T5 Magnesium Alloy Plate

Metals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1170
Author(s):  
Chalasani Dharmendra ◽  
Mukesh Jain ◽  
Yellapregada Prasad ◽  
Kamineni Pitcheswara Rao
Keyword(s):  
Magnesium Alloy ◽  
Transverse Direction ◽  
Processing Map ◽  
Texture Evolution ◽  
Normal Direction ◽  
Hot Compression ◽  
Slip Systems ◽  
Alloy Plate ◽  
Pyramidal Slip ◽  
Pole Figures

The texture evolution during hot compression of extruded ZK60A-T5 magnesium alloy plate loaded along the extrusion direction (ED) and the normal direction (ND) has been examined with the help of pole figures obtained on specimens deformed in the ranges of 200 °C to 500 °C and 0.0003 s−1 to 10 s−1. The results are interpreted in terms of the operating slip systems and mechanisms identified based on processing maps developed for the above two initial specimen orientations. The processing map for the initial ED orientation exhibited three domains. In Domains 1 and 3, first-order pyramidal slip {10 1 ¯ l} <11 2 ¯ 0> occurs, while in Domain 2, second-order pyramidal slip {11 2 ¯ 2} <11 2 ¯ 3> occurs. The pole figures obtained on specimens deformed in Domains 1 and 3 are strikingly similar, indicating that the operating slip system controls the texture evolution. Compression in Domains 1 and 3 nearly randomizes the intense basal texture in the as-received specimens, while a new texture is generated in Domain 2 with basal poles at 45° to ND or transverse direction (TD). This new texture will promote basal slip when loaded in a transverse direction. When loaded in the normal direction (ND), the processing map exhibited four domains. In Domains 1 and 4, {10 1 ¯ l} <11 2 ¯ 3> slip occurs, while {11 2 ¯ 2} <11 2 ¯ 3> slip occurs in Domains 2 and 3. The pole figures obtained from specimens deformed in Domains 1 and 4 have similar features, while those deformed in Domains 2 and 3 exhibited similar features to one another, confirming that the operating slip systems control the texture development since they are the same in each pair. The compression along ND produces strong basal textures with the basal planes normal to the ED. The texture gets intensified with increased temperature of deformation and causes strong anisotropy in mechanical properties.

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.

Investigation of Localized Deformation in NiAl Single Crystals

1998 ◽  
Vol 120 (3) ◽  
pp. 206-211 ◽  
Author(s):  
Ashok V. Kumar ◽  
Chulho Yang ◽  
Vijay B. R. Seelam
Keyword(s):  
Single Crystals ◽  
Shear Bands ◽  
Slip Systems ◽  
Localized Deformation ◽  
Localized Modes ◽  
Element Analysis ◽  
Kink Bands ◽  
Simulation Results ◽  
Constitutive Parameters ◽  
Active Slip

Deformation of NiAl single crystals was studied using finite element analysis to investigate the modes of localized deformation. Constitutive parameters and hardening characteristics of the active slip systems were estimated by comparing numerical simulation results with experimental results. Deformation of tensile specimens of NiAl single crystal was simulated when loaded along different crystal orientations to understand the deformation mechanism that results in various localized modes of deformation. In particular, the formation of shear bands and kink bands was studied and the material and geometric characteristics that influence the formation of such localization were investigated.

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