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采用分子动力学模拟方法研究了旋转晶界角对铜孪晶纳米线拉伸加载下力学性能的影响。模拟采用多体紧束缚势函数描述铜原子间的相互作用。通过模拟结果,分析了单晶铜和孪晶铜之间的差异,以及不同旋转晶界角的铜孪晶纳米线的位错成核机制。结果表明:随着旋转晶界角的增加,铜纳米线的屈服强度减弱;当旋转晶界角较小时,界面上出现了成三角形网格的失配位错,随着旋转晶界角的增大,网格逐渐缩小甚至消失;旋转晶界角较大时,晶界处易于位错成核,且界面对位错的存储能力和阻碍作用均减弱,导致屈服强度减弱。
Molecular dynamics simulation was used to study the influence of the rotation angle on the mechanical properties of copper twinned nanowires under tensile loading. The simulation uses the multibody tight binding potential function to describe the interaction between copper atoms. Through the simulation results, the differences between single crystal copper and twinned copper and the dislocation nucleation mechanism of copper twinned nanowires with different angles of rotation are analyzed. The results show that the yield strength of the copper nanowires decreases with the increase of the angle of the grain boundary. When the rotation angle is small, the misfit dislocations of the triangular grids appear at the interface. The mesh gradually shrinks or even disappears. When the rotation grain boundary angle is large, the dislocations are easily nucleated at the grain boundaries, and the storage and blocking effects of dislocations at the interface are weakened, resulting in weaker yield strength.