中国物理B ›› 2001, Vol. 10 ›› Issue (5): 407-412.doi: 10.1088/1009-1963/10/5/309
• ATOMIC AND MOLECULAR PHYSICS • 上一篇 下一篇
文玉华, 周富信, 刘曰武
Wen Yu-hua (文玉华), Zhou Fu-xin (周富信), Liu Yue-wu (刘曰武)
摘要: Nanocrystalline (nc) materials are characterized by a typical grain size of 1-100nm. The uniaxial tensile deformation of computer-generated nc samples, with several average grain sizes ranging from 5.38 to 1.79nm, is simulated by using molecular dynamics with the Finnis-Sinclair potential. The influence of grain size and temperature on the mechanical deformation is studied in this paper. The simulated nc samples show a reverse Hall-Petch effect. Grain boundary sliding and motion, as well as grain rotation are mainly responsible for the plastic deformation. At low temperatures, partial dislocation activities play a minor role during the deformation. This role begins to occur at the strain of 5%, and is progressively remarkable with increasing average grain size. However, at elevated temperatures no dislocation activity is detected, and the diffusion of grain boundaries may come into play.
中图分类号: (Mechanical properties of nanoscale systems)