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本文利用分子动力学方法研究了<001>/{100}和<110>/{111}两种单晶铜纳米线在弯曲、扭转载荷作用下的变形机制和力学行为.在<001>/{100}铜纳米线的弯曲过程中,当弯曲角度很大时,我们观察到了一些五重变形孪晶.分析表明,配位数为12的其它原子类型与hcp原子类型间的相互转化是导致出现这种五重变形孪晶的重要因素.这个结果与文献(Appl Phys Lett,2006,89:041919)所报道的纳米晶铜在拉伸状态下所观察到的五重变形孪晶的形成过程截然不同;然而该孪生变形机制并未在相应的?110?/{111}单晶铜纳米线的弯曲加载过程中被发现.此外,通过对<001>/{100}和?110?/{111}单晶铜纳米线进行扭转模拟,我们发现,这两种纳米线的扭转塑性变形分别是以从表面边角和侧表面发射全位错为主的变形机制.
In this paper, the deformation mechanism and mechanical behavior of two kinds of single crystal copper nanowires <001> / {100} and <110> / {111} under bending and torsional loading were studied by using molecular dynamics method. 100} copper nanowires, we observed some pentagonal deformation twins when the bending angle was large.The analysis shows that the mutual transformation between other atomic types with coordination number 12 and the hcp atomic type leads to the appearance of This five-fold deformation twin important factor.This result and the literature (Appl Phys Lett, 2006,89: 041919) reported nanocrystalline copper tensile state observed in the formation of pentagonal deformation twins However, the mechanism of twin deformation was not found during the bending loading of the corresponding 110N / 111N single crystal copper nanowires.In addition, the mechanism of the deformation of <001> / {100} and {110} / {111 } Single crystal copper nanowires were simulated torsionally and we found that the torsional plastic deformation of the two kinds of nanowires are based on the deformation mechanism of total dislocation emanating from the surface corner and side surface, respectively.