小角度非对称倾侧晶界形貌和变形的晶体相场模拟

采用双模晶体相场模型,计算了二维正方相相图,并以正方相为研究对象,在原子尺度上,模拟了小角度非对称倾侧晶界结构及变形过程。结果表明,小角度非对称倾侧晶界由刃型位错和刃型位错组构成;在外加应力作用下,位错先于位错组滑移并进行短程的攀移,最后合并,位错组分离为滑移方向相反的2个刃型位错并最终与其它晶界位错组分离出的异号刃型位错合并,完成晶粒的合并。

Simulation of Structure and Deformation of Asymmetrical Tilt Grain Boundaries with Small Misorientation Angles by Two-Mode Phase Field Crystal Method

The phase diagram of the two-dimensional square lattices was calculated using the two-mode phase field crystal model. The structure and deformation of asymmetrical tilt grain boundaries (GBs) with small misorientation angles was simulated. The results show that asymmetrical tilt GBs are composed of dislocations and double-array dislocations. The dislocations glide before double-array dislocations and climb across a short distance to merge with the negative dislocations under applied stress. The double-array dislocations are separated by two dislocations, which glide to the opposite direction and merge with negative dislocation separated from other double-array dislocations