Atomistic Investigation of Probe-Based Nanomachining on Cu Twin Boundaries

作者：Zhang Junjie; Sun Tao^*; Yan Yongda; He Yusong; Liang Yingchun; Dong Shen

来源：Journal of Computational and Theoretical Nanoscience, 2011, 8(11): 2344-2349.

DOI：10.1166/jctn.2011.1966

• Nanomachining
• Twin Boundary
• Dislocation
• Molecular Dynamics

The interaction of dislocations with grain boundaries can significantly alter mechanical response of nanocrystalline materials under applied load. In current work, we investigate deformation behavior of Cu twin boundaries under probe-based nanomachining by means of molecular dynamics simulations. Our simulation results suggest that twin boundaries can lower the critical stress required for initial dislocation nucleation, meanwhile act as strong barriers to subsequent dislocation motion. Different kinds of dislocation-twin boundary interaction, such as confinement, adsorption and transmission accompanied with twin boundary migration, are observed during nanomachining process. It is found the significant work-hardening caused by twin boundaries blocking dislocation motions leads to higher scratching resistance of Cu sample with twin boundaries than single crystal case. Subsequent evaluation reveals the twin boundary spacing dependence of dislocation-twin boundary interaction during nanomachining: the smaller the twin boundary spacing, the larger the strength, and the higher the scratching resistance. It is indicated dislocation transmission through twin boundary is more easily occurred in Cu sample with smaller twin boundary spacing.

• 出版日期2011-11
• 单位哈尔滨工业大学