Faceted grain boundaries can migrate in interesting and unexpected ways. For example, faceted Σ11 $\langle 110\rangle$ tilt grain boundaries were observed to exhibit mobility values that could be strongly dependent on the direction of migration. In order to understand whether this directionally anisotropic mobility is a general phenomenon and to isolate mechanistic explanations for this behavior, molecular dynamics simulations of bicrystals evolved under an artificial driving force are used to study interface migration for a range of boundary plane inclination angles and temperatures in multiple face-centered-cubic metals (Al, Ni, and Cu). We find that directionally anisotropic mobility is active in a large fraction of these boundaries in Ni and Cu and should therefore impact the coarsening of polycrystalline materials. On the other hand, no such anisotropy is observed in any of the Al boundaries, showing that this behavior is material dependent. Migration of the faceted boundaries is accomplished through transformation events at facet nodes and incommensurate boundary plane facets, which are termed shuffling modes. Three major shuffling modes have been identified, namely, Shockley shuffling, slip plane shuffling, and disordered shuffling. A shift from the first two ordered modes to the third disordered mode is found to be responsible for reducing or removing directionally anisotropic mobility, especially at the highest temperatures studied.

中文翻译：

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混洗模式竞争导致fcc金属中刻面Σ11边界的方向各向异性迁移率

刻面晶界可以以有趣且出乎意料的方式迁移。例如，多面Σ11$〈110〉$观察到倾斜的晶界显示出迁移率值，该迁移率值可能很大程度上取决于迁移方向。为了了解这种方向各向异性的迁移率是否是普遍现象，并且为了对此现象进行机理解释，在人工驱动力作用下生成的双晶分子动力学模拟用于研究一定范围内的边界平面倾角和温度下的界面迁移。多种面心立方金属（Al，Ni和Cu）。我们发现，在镍和铜的这些边界的很大一部分中，方向各向异性迁移率很活跃，因此应该影响多晶材料的粗化。另一方面，在任何Al边界中均未观察到这种各向异性，表明该行为与材料有关。刻面边界的迁移是通过刻面节点和不相称的边界平面刻面的转换事件来完成的，这些转换事件被称为混洗模式。已经确定了三种主要的混洗模式，即肖克利混洗，滑移混洗和无序混洗。发现从前两个有序模式到第三个无序模式的转变是导致方向各向异性迁移率降低或消除的原因，特别是在研究的最高温度下。