物理化学学报 >> 2007, Vol. 23 >> Issue (04): 517-520.doi: 10.3866/PKU.WHXB20070413

研究论文 上一篇    下一篇

应变率诱发镍纳米丝的非晶化

彭传校; 王丽; 张妍宁   

  1. 山东大学材料液态结构及其遗传性教育部重点实验室, 济南 250061
  • 收稿日期:2006-10-08 修回日期:2006-11-28 发布日期:2007-04-05
  • 通讯作者: 彭传校 E-mail:believechx@163.com

Amorphization of Ni Nanowires Induced by Strain Rate

PENG Chuan-Xiao; WANG Li; ZHANG Yan-Ning   

  1. Key Laboratory of Liquid Structure and Heredity of Materials, Ministry of Education, Shandong University, Jinan 250061, P. R. China
  • Received:2006-10-08 Revised:2006-11-28 Published:2007-04-05
  • Contact: PENG Chuan-Xiao E-mail:believechx@163.com

摘要: 采用镶嵌原子法(EAM)作用势对镍纳米丝的拉伸过程进行了分子动力学模拟. 体系施加应变率范围在5×10^7 - 1×10^10 s^-1, 观察体系的应力-应变曲线、平均原子能量、原子轨迹, 偶相关函数随应变率的变化. 发现当应变率低于1×10^8 s^-1时, 体系发生塑性变形, 最终颈缩断裂, 偶相关函数表明体系一直保持晶体结构; 而当应变率高于1×10^9 s^-1时, 体系发生了由晶体向非晶的持续转变, 偶相关函数出现了典型的非晶峰, 高应变率诱发了Ni纳米丝的非晶化.

关键词: 分子动力学模拟, 应力-应变曲线, 非晶化

Abstract: Molecular dynamics simulations were performed for studying mechanical properties of nickel nanowires subjected to uniaxial strain using embedded atommethod (EAM) potential. Strain rates applied in the simulations ranged from 5×10^7 s^-1 to 1×10^10 s^-1. The stress, the average atomic energy, the pair correlation function, as well as the transient atomic images of the systems were presented to explore the strain rate dependence of structure of nanowires. It was found that as the strain rates applied to the system were lower than 1×10^8 s^-1, the nanowires underwent plastic deformation and kept crystal structure before fracture during the process of tensioning state, which was testified clearly by the pair correlation function. While as strain rates were higher than 1×10^9 s^-1, the nanowires changed continuously from crystalline structure to amorphous phase and the pair correlation function also exhibited the characteristics of typical amorphous peaks. Amorphization of Ni nanowires was induced under high strain rates.

Key words: Molecular dynamics simulation, Stress-strain curves, Amorphization

MSC2000: 

  • O645