Abstract Crack propagation and crack-defect (void) interactions are investigated in nickel nanowires (NWs) of [010], [1-10], and [111] axial crystallographic orientations by subjecting to tensile loading (mode-I) at a temperature of 10 K and strain rate of 109 s-1. From the molecular dynamic (MD) simulation results, it is observed that crack does not propagate in the [111] orientation NW. The crack velocity is 313 m/s in [010] orientation nickel NW with crack. The predominant deformation mechanisms are slip by Shockley partial dislocation in [010], [111] orientations, and twinning in [1-10] orientation. With the decrease in crack-void spacing from 20 A to 5 A, the average crack velocities (207 m/s-120 m/s) decrease in [010] orientation due to crack tip blunting arising from the crack-void coalescence. Three point bending simulations studies carried out on the above mentioned NWs also show similar deformation mechanism features and a decrease in crack velocities from 130 m/s-77 m/s.

中文翻译：

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使用大规模分子动力学模拟在模式 I 和弯曲下具有裂纹、裂纹缺陷的镍纳米线的裂纹速度和微观结构研究

摘要 通过在一定温度下承受拉伸载荷（模式 I），研究了 [010]、[1-10] 和 [111] 轴向结晶取向的镍纳米线 (NW) 中的裂纹扩展和裂纹缺陷（空隙）相互作用。 10 K 和应变率为 109 s-1。从分子动力学 (MD) 模拟结果可以看出，裂纹不会沿 [111] 取向 NW 扩展。[010] 取向镍 NW 裂纹速度为 313 m/s。主要的变形机制是 [010]、[111] 方向的肖克利部分位错滑移和 [1-10] 方向的孪晶。随着裂纹空隙间距从 20 A 减小到 5 A，由于裂纹空隙合并引起的裂纹尖端钝化，平均裂纹速度 (207 m/s-120 m/s) 在 [010] 取向上降低。