单晶和多晶钼纳米丝轴向拉伸的模拟对比-中国有色金属学报.PDF

19 11 2009 11 Vol.19 No.11 The Chinese Journal of Nonferrous Metals Nov. 2009 1004-0609(2009)11-1982-05 , ( 410082) TG 113.25 A Comparison of simulation of single-crystalline and polycrystalline Mo nanowires under uniaxial tensile strain 1 1 1 1 LI Xiao-fan , HU Wang-yu , XIAO Shi-fang , DENG Hui-qiu (1. School of Physics and Microelectronics Science, Hunan University, Changsha 410082, China) Abstract: Using molecular dynamic simulations, the difference of tensile deformation behavior between the polycrystalline Mo nanowires and single-crystalline counterparts was investigated. The results show that, compared with the polycrystalline nanowires, the single-crystalline nanowires have higher elastic modulus, yield strength and fracture strain, and more local atomic structural evolutions and amorphization exist during tensile strain, which results in the superplasticity behaviors of single-crystalline nanowires. For the polycrystalline nanowires, the necking commences from the grain boundary regions of high stress concentration, and the local atomic structural transitions happen only near these regions. Thus, the degree of structure order is rarely affected with increasing strain. The high stresses found in the grain boundary regions of polycrystalline nanowires clearly play a dom