Computer simulation of texture evolution during grain growth: effect of boundary properties and initial microstructure

2004 ◽  
Vol 52 (13) ◽  
pp. 3869-3879 ◽  
Author(s):  
N Ma ◽  
A Kazaryan ◽  
S.A Dregia ◽  
Y Wang
2007 ◽  
Vol 558-559 ◽  
pp. 803-809 ◽  
Author(s):  
Kasra Sotoudeh ◽  
Pete S. Bate ◽  
John F. Humphreys

The effect of copper content on dynamic grain growth in Al-Cu-Zr system was investigated by studying the microstructural development and texture evolution during uniaxial tensile deformation of Al-2wt%Cu-0.3wt.%Zr and Al-4wt%Cu-0.4wt.%Zr alloys at 450°C with a strain rate of 10-3s-1, with a similar initial microstructure in both materials. The initial microstructure consisted of layers of different orientations, the layers being separated by high-angle grain boundaries with low-angle boundaries separating grains within the layers. The initial grain spacing was about 5m and the texture was typical of rolled aluminium alloys. The 4wt.%Cu alloy gave a higher strain rate sensitivity index, m, and a greater ductility compared to the low copper content alloy. An increase in grain size occurred in both materials due to deformation, but this dynamic grain growth (DGG) was much greater in the material with the higher copper content. This was associated with a more rapid conversion of low-angle boundaries to high angle ones in the 4wt%Cu material which is consistent with changes in crystallographic texture occurring during deformation.


2004 ◽  
Vol 467-470 ◽  
pp. 715-726 ◽  
Author(s):  
Moneesh Upmanyu ◽  
Zachary T. Trautt ◽  
Branden B. Kappes

Anisotropy in grain boundary “thermo-kinetics” is central to our understanding of microstructural evolution during grain growth and recrystallization. This paper focusses on role of atomic-scale computer simulation techniques, in particular molecular dynamics (MD), in extracting fundamental grain boundary properties and elucidating the atomic-scale mechanisms that determine these properties. A brief overview of recent strides made in extraction of grain boundary mobility and energy is presented, with emphasis on plastic strain induced boundary motion (p-SIBM) during recrystallization and curvature driven boundary motion (CDBM) during grain growth. Simulations aimed at misorientation dependence of the grain boundary properties during p-SIBM and CDBM show that boundary mobility and energy exhibit extrema at high symmetry misorientations and boundary mobility is comparatively more anisotropic during CDBM. This suggests that boundary mobility is dependent on the driving force. Qualitative observations of the atomic-scale mechanisms in play during boundary motion corroborate the simulation data. p-SIBM is dominated by motion of dislocation-interaction induced stepped structure of the grain boundaries, while correlated shuffling of group of atoms preceded by rearrangement of grain boundary free volume due to single atomic-hops across the grain boundary is frequently observed during CDBM. Comparison of the simulation results with high-purity experimental data extracted in Al indicates that while there is excellent agreement in misorientation dependent anisotropic properties, there are significant differences in values of boundary mobility and migration activation enthalpy. This strongly suggests that minute concentration of impurities retard grain boundary kinetics via impurity drag. Finally, the paper briefly discusses current and future challenges facing the computer simulation community in studying grain boundary systems in real materials where extrinsic effects (vacancy, impurity, segregation and particle effects) significantly alter the microscopic structure-mechanism relations and play a decisive role in determining the boundary properties.


1994 ◽  
Vol 343 ◽  
Author(s):  
J. A. Floro ◽  
C. V. Thompson

ABSTRACTAbnormal grain growth is characterized by the lack of a steady state grain size distribution. In extreme cases the size distribution becomes transiently bimodal, with a few grains growing much larger than the average size. This is known as secondary grain growth. In polycrystalline thin films, the surface energy γs and film/substrate interfacial energy γi vary with grain orientation, providing an orientation-selective driving force that can lead to abnormal grain growth. We employ a mean field analysis that incorporates the effect of interface energy anisotropy to predict the evolution of the grain size/orientation distribution. While abnormal grain growth and texture evolution always result when interface energy anisotropy is present, whether secondary grain growth occurs will depend sensitively on the details of the orientation dependence of γi.


2020 ◽  
Vol 10 (14) ◽  
pp. 2070060
Author(s):  
Se‐Yun Kim ◽  
Dae‐Ho Son ◽  
Seung‐Hyun Kim ◽  
Young‐Ill Kim ◽  
Sammi Kim ◽  
...  

2011 ◽  
Vol 306-307 ◽  
pp. 116-119
Author(s):  
Masahiko Demura ◽  
Ya Xu ◽  
Toshiyuki Hirano

This article presents the texture evolution and the ductility improvement of the cold-rolled foils of boron-free Ni3Al during the recrystallization and the subsequent grain growth. The cold-rolled foils had sharp {110} textures. After the recrystallization at 873K/0.5h, the texture was disintegrated with several texture components. Interestingly, most of them had a single rotation relationship. i.e. 40˚ around <111>. With the progress of the grain growth, however, the texture returned to the sharp, cold-rolled textures. This two-stage texture evolution, called as “Texture memory effect”, was explained assuming a high mobility of the grain boundary with the 40˚<111> rotation relationship. The texture returning was highly effective to improve the ductility of the foils.


2005 ◽  
Vol 495-497 ◽  
pp. 749-754 ◽  
Author(s):  
Chang Sik Ha ◽  
Yong Bum Park

In electroformed pure Ni and Fe-Ni alloys with nanometer-sized crystallites, grain growth that takes place during annealing results in a common texture change. With regard to the macrotextures, the as-deposited textures were of fibre-type characterized by strong <100>//ND and weak <111>//ND components, and the texture development due to grain growth was defined by strong <111>//ND fibre texture with the minor <100>//ND components. It was clarified by means of the microtexture analysis that abnormal growth of the <111>//ND grains occurs in the early stages of grain growth. The possible effects of the abnormal grain growth on the texture evolution have been discussed in terms of the orientation dependence of energy density.


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