A grain boundary model considering the grain misorientation within a geometrically nonlinear gradient-extended crystal viscoplasticity theory
A grain boundary model considering the grain misorientation within a geometrically nonlinear gradient-extended crystal viscoplasticity theory
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DOI：
10.1098/rspa.2019.0581
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发表时间：
2020-03-25
影响因子：
3.5
通讯作者：
Wulfinghoff, Stephan
中科院分区：
文献类型：
--
作者：
Alipour, Atefeh;Reese, Stefanie;Wulfinghoff, Stephan
目前工作的主要目标是提出一个晶界模型的基础上相邻晶粒之间的失配在一个几何非线性晶体粘塑性框架，包括位错密度张量的影响。为此，Alipour等人的几何非线性晶体粘塑性理论（Alipour A et al. 2019 Int. J. Plast. 118，17-35。())通过一个更复杂的自由能和几何传输率参数来评估位错传输在晶界，其中包括滑移方向和滑移面法线的取向。然后，晶界强度评估的基础上相邻晶粒之间的取向差使用的传输率参数。通过对二维随机取向多晶体和织构多晶体在剪切变形下的比较，讨论了相邻晶粒间的失配对晶界强度、晶界位错传输和Hall-Petch斜率的影响。
The main goal of the current work is to present a grain boundary model based on the mismatch between adjacent grains in a geometrically nonlinear crystal viscoplasticity framework including the effect of the dislocation density tensor. To this end, the geometrically nonlinear crystal viscoplasticity theory by Alipour et al. (Alipour A et al. 2019 Int. J. Plast. 118, 17-35. ()) is extended by a more complex free energy and a geometrical transmissibility parameter is used to evaluate the dislocation transmission at the grain boundaries which includes the orientations of slip directions and slip plane normals. Then, the grain boundary strength is evaluated based on the misorientation between neighbouring grains using the transmissibility parameter. In some examples, the effect of mismatch in adjacent grains on the grain boundary strength, the dislocation transmission at the grain boundaries and the Hall-Petch slope is discussed by a comparison of two-dimensional random-oriented polycrystals and textured polycrystals under shear deformation.