Wan Liang, Han Weizhong, Chen Kai
Center for Advancing Materials Performance from the Nanoscale, State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, China.
Sci Rep. 2015 Aug 25;5:13441. doi: 10.1038/srep13441.
Shear stress driven grain boundary (GB) migration was found to be a ubiquitous phenomenon in small grained polycrystalline materials. Here we show that the GB displacement shift complete (DSC) dislocation mechanism for GB shear coupled migration is still functioning even if the geometry orientation of the GBs deviates a few degrees from the appropriate coincidence site lattice (CSL) GBs. It means that any large angle GB can have a considerable chance to be such a "CSL-related GB" for which the shear coupled GB migration motion can happen by the GB DSC dislocation mechanism. We conclude that the CSL-DSC bi-crystallographic lattice structure in GB is the main reason that GB can migrate under shear stress.
在小晶粒多晶材料中，剪应力驱动的晶界迁移是一种普遍存在的现象。本文表明，即使晶界的几何取向与适当的重合位置点阵（CSL）晶界有几度偏差，用于晶界剪切耦合迁移的晶界位移完全（DSC）位错机制仍然起作用。这意味着任何大角度晶界都有相当大的机会成为这样一种“与CSL相关的晶界”，对于这种晶界，剪切耦合晶界迁移运动可以通过晶界DSC位错机制发生。我们得出结论，晶界中的CSL-DSC双晶体点阵结构是晶界在剪应力作用下能够迁移的主要原因。
