The grain boundary stiffness and its impact on equilibrium shapes and boundary migration: Analysis of the Σ 5, 7, 9, and 11 boundaries in Ni
The grain boundary stiffness and its impact on equilibrium shapes and boundary migration: Analysis of the Σ 5, 7, 9, and 11 boundaries in Ni
复制标题
晶界刚度及其对平衡形状和晶界迁移的影响：Ni 中 Σ 5、7、9 和 11 晶界的分析
DOI：
10.1016/j.actamat.2021.117220
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发表时间：
2021
期刊：
影响因子：
9.4
通讯作者：
Abdeljawad, Fadi
中科院分区：
文献类型：
--
作者：
Moore, Robert D.;Beecroft, Timothy;Rohrer, Gregory S.;Barr, Christopher M.;Homer, Eric R.;Hattar, Khalid;Boyce, Brad L.;Abdeljawad, Fadi
晶界对材料加工过程中微观组织的形成及其在使用条件下的后续演变起着至关重要的作用。虽然GB错取向通常用于描述边界的性质，但更完整的描述还应考虑到GB平面法向，其中GB刚度是控制许多GB动力学过程的相关性质。在此，我们利用已发表的原子模拟数据来构建Σ 5、7、9和11 GB Ni的全GB能量平面法线图。利用函数拟合得到国标刚度与平面法线的完整映射，构造平衡形状，确定国标迁移的驱动力。结果表明，与能量本身相比，GB刚度可以具有更大的量级和更强的各向异性。此外，发现许多边界倾斜度表现出负刚度，表明面形倾向。我们的GB刚度分析结果与多晶Ni中GB平面正态分布的实验结果在定性上一致。从广义上讲，我们的研究结果为在GB迁移和微观结构演化的中尺度处理中解释GB性质的平面法向依赖性提供了未来的途径。
Grain boundaries (GBs) play a critical role in the formation of microstructure during materials processing and its subsequent evolution under service conditions. While GB misorientation is commonly used to describe the boundary’s properties, a more complete description should also account for the GB plane normal, in which the GB stiffness is the relevant property controlling many GB dynamical processes. Herein, we leverage published atomistic simulation data to construct the full GB energy–plane normal diagrams for Σ 5, 7, 9, and 11 GBs in Ni. The functional fits are used to obtain a complete mapping of the GB stiffness as a function of the plane normal, construct the equilibrium shapes, and determine the driving force for GB migration. It is shown that the GB stiffness can be larger in magnitude and more anisotropic than the energy itself. Further, many boundary inclinations are found to exhibit negative stiffness, indicating propensity for faceting. Results from our GB stiffness analysis are shown to be in qualitative agreement with experimental GB plane normal distributions in polycrystalline Ni. In broad terms, our results provide future avenues to account for the plane normal dependency of GB properties in mesoscale treatments of GB migration and microstructural evolution.