Periodic crystal lattice rotation in microband groups in a bcc metal

2007 ◽  
Vol 57 (8) ◽  
pp. 775-778 ◽  
Author(s):  
Dorothée Dorner ◽  
Yoshitaka Adachi ◽  
Kaneaki Tsuzaki
Keyword(s):  
Crystal Lattice ◽  
Lattice Rotation ◽  
Bcc Metal ◽  
Periodic Crystal

Characterization of Plastic Deformation Induced by Microscale Laser Shock Peening

2004 ◽  
Vol 71 (5) ◽  
pp. 713-723 ◽  
Author(s):  
Hongqiang Chen ◽  
Jeffrey W. Kysar ◽  
Y. Lawrence Yao
Keyword(s):  
Plastic Deformation ◽  
Single Crystal ◽  
Crystal Lattice ◽  
Electron Backscatter Diffraction ◽  
Fem Analysis ◽  
Copper Sample ◽  
Laser Shock Peening ◽  
Lattice Rotation ◽  
Laser Shock ◽  
Shock Peening

Electron backscatter diffraction (EBSD) is used to investigate crystal lattice rotation caused by plastic deformation during high-strain rate laser shock peening in single crystal aluminum and copper sample on 110¯ and (001) surfaces. New experimental methodologies are employed which enable measurement of the in-plane lattice rotation under approximate plane-strain conditions. Crystal lattice rotation on and below the microscale laser shock peened sample surface was measured and compared with the simulation result obtained from FEM analysis, which account for single crystal plasticity. The lattice rotation measurements directly complement measurements of residual strain/stress with X-ray micro-diffraction using synchrotron light source and it also gives an indication of the extent of the plastic deformation induced by the microscale laser shock peening.

Shear Banding in Polycrystalline Aluminium and Copper Pre-Deformed by ECAP and Subsequently Plane Strain Compressed

2016 ◽  
Vol 716 ◽  
pp. 240-247
Author(s):  
Henryk Paul ◽  
Magdalena M. Miszczyk
Keyword(s):  
Crystal Lattice ◽  
Grain Boundaries ◽  
Texture Evolution ◽  
Shear Banding ◽  
Shear Bands ◽  
Shear Plane ◽  
Lattice Rotation ◽  
Pure Aluminium ◽  
Electron Backscattered Diffraction ◽  
Angular Pressing

The microstructure and texture evolution in commercially pure aluminium (AA1050 alloy) and copper have been characterized after change in strain path to elucidate the mechanisms of shear bands (SBs) formation and propagation across grain boundaries. Samples were pre-deformed in equal channel angular pressing (ECAP) and further compressed in a channel-die to form two sets of macro-SBs. The deformation-induced sub-structures and local changes in crystallographic orientations were characterized by scanning electron microscopy equipped with a high-resolution electron backscattered diffraction facility. It was found that the mechanism of micro-/macro-SBs formation is strictly crystallographic. In all the grains of the sheared zone a strong tendency to strain-induced re-orientation could be observed. Their crystal lattice rotated in such a way that one of the {111} slip planes became nearly parallel to the shear plane and the <011> (or <112>) direction became parallel to the direction of maximum shear. This crystal lattice rotation led to the formation of specific SBs components which facilitates slip propagation across grain boundaries without any visible variation in the slip direction.

Effect of Intergranular Interaction and Lattice Rotation on Predicted Residual Stress and Textures. Case of Austenite and Ferrite

2013 ◽  
Vol 772 ◽  
pp. 97-101
Author(s):  
Krzysztof Wierzbanowski ◽  
Marcin Wronski ◽  
Andrzej Baczmanski ◽  
Paul Lipiński ◽  
Brigitte Bacroix ◽  
...  
Keyword(s):  
Residual Stress ◽  
Plastic Deformation ◽  
Crystal Lattice ◽  
Basic Mechanism ◽  
Lattice Rotation ◽  
Polycrystalline Materials ◽  
Deformation Model ◽  
Anisotropic Behavior ◽  
Matrix Interaction ◽  
Definition Of

Rotation of grain crystal lattice is the basic mechanism of texture formation and of anisotropic behavior of metals during plastic deformation. The classical definition of crystal lattice rotation leads in some cases to different texture and residual stress predictions than the definition based on the orientation preservation of selected sample planes and/or directions. Also the intensity of grain-matrix interaction plays an important role in the prediction of the above quantities. These problems were studied using elasto-plastic deformation model of polycrystalline materials. Examples of austenite and ferrite steels were considered.

scholarly journals Evaluation of Crystal Lattice Rotation around a Stress-Induced Twin in a Step-Graded SiGe / Si (110) Using STEM Moiré Observation and its Image Analysis

2019 ◽  
Vol 25 (S2) ◽  
pp. 242-243
Author(s):  
Junji Yamanaka ◽  
Chiaya Yamamoto ◽  
Mai Shirakura ◽  
Kosuke O. Hara ◽  
Keisuke Arimoto ◽  
...  
Keyword(s):  
Image Analysis ◽  
Crystal Lattice ◽  
Lattice Rotation

Unrecoverable Strain Hardening in Torsionally Strained OFHC Copper

1990 ◽  
Vol 112 (3) ◽  
pp. 315-320 ◽  
Author(s):  
D. P. Field ◽  
B. L. Adams
Keyword(s):  
Crystal Lattice ◽  
Shear Strain ◽  
Strain Hardening ◽  
Texture Evolution ◽  
Lattice Rotation ◽  
Ofhc Copper ◽  
Softening Effect ◽  
Recoverable Strain ◽  
Torsional Strain ◽  
Shear Strains

This paper investigates the recoverable and unrecoverable components of strain hardening in OFHC copper tubing subjected to torsional strain. Individual hardening components are classified and the magnitude of each is experimentally determined. Recoverable strain hardening is defined to be the difference between the final shear stress and the yield stress measured after recovery annealing. The recoverable hardening, due primarily to dislocation pileups, accounts for about 95.5 percent of the measured strain hardening at a shear strain of 1.9. Crystal lattice rotation during shear strain accounts for a portion of the unrecoverable hardening at shear strains less than .25, but becomes a strain softening effect at shear strains above .5. The evolution of the texture is measured experimentally and analyzed using both Taylor’s and Kochendorfer’s models. Texture evolution is also simulated up to a shear strain of 2.0 using Taylor’s model. This simulation yields similar results to the measured texture in determining strain hardening caused by rotation of the crystal lattice. The softening effect of crystalline reorientation accounts for a decrease in the observable hardening of 1.5 percent at a shear strain of 1.9.

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