Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1564050 | Computational Materials Science | 2008 | 8 Pages |
Abstract
We present the analysis of uniaxial deformation of nickel nanowires using molecular dynamics simulations, and address the strain rate effects on mechanical responses and deformation behavior. The applied strain rate is ranging from 1Â ÃÂ 108Â sâ1 to 1.4Â ÃÂ 1011Â sâ1. The results show that two critical strain rates, i.e., 5Â ÃÂ 109Â sâ1 and 8Â ÃÂ 1010Â sâ1, are observed to play a pivotal role in switching between plastic deformation modes. At strain rate below 5Â ÃÂ 109Â sâ1, Ni nanowire maintains its crystalline structure with neck occurring at the end of loading, and the plastic deformation is characterized by {1Â 1Â 1} slippages associated with Shockley partial dislocations and rearrangements of atoms close to necking region. At strain rate above 8Â ÃÂ 1010Â sâ1, Ni nanowire transforms from a fcc crystal into a completely amorphous state once beyond the yield point, and hereafter it deforms uniformly without obvious necking until the end of simulation. For strain rate between 5Â ÃÂ 109Â sâ1 and 8Â ÃÂ 1010Â sâ1, only part of the nanowire exhibits amorphous state after yielding while the other part remains crystalline state. Both the {1Â 1Â 1} slippages in ordered region and homogenous deformation in amorphous region contribute to the plastic deformation.
Related Topics
Physical Sciences and Engineering
Engineering
Computational Mechanics
Authors
Yu-Hua Wen, Zi-Zhong Zhu, Ru-Zeng Zhu,