含有{111}织构的纳米孪晶多晶铜在拉伸变形过程中塑性各向异性机制的分子动力学模拟

基于分子动力学模拟,从主导滑移系的斯密特因子和位错机制两个方面系统研究含有{111}织构的纳米孪晶多晶铜在拉伸变形过程中的塑性各向异性机制.结果表明:主导滑移系的斯密特因子随着孪晶界倾角的改变而变化,但屈服应力或流动应力并不严格遵守斯密特定律.在拉伸变形过程中存在涉及不同位错机制的硬取向和软取向.硬取向的硬化机制在于塑...

Molecular dynamics simulation on mechanisms of plastic anisotropy in nanotwinned polycrystalline copper with {111} texture during tensile deformation

Based on molecular dynamics (MD) simulation, the mechanisms of plastic anisotropy in nanotwinned polycrystalline copper with {111} texture during tensile deformation were systematically studied from the aspects of Schmid factor of the dominant slip system and the dislocation mechanism. The results show that the Schmid factor of dominated slip system is altered by changing the inclining angle of the twin boundaries (TBs), while the yield stress or flow stress does not strictly follow the Schmid law. There exist hard and soft orientations involving different dislocation mechanisms during the tensile deformation. The strengthening mechanism of hard orientation lies in the fact that there exist interactions between the dislocations and the TBs during plastic deformation, which leads to the dislocation blocking and reactions. The softening mechanism of soft orientation lies in the fact that there is no interaction between the dislocations and the TBs because only the slip systems parallel to the TBs are activated and the dislocations slip on the planes parallel to the TBs. It is concluded that the plastic anisotropy in the nanotwinned polycrystalline copper with {111} texture is aroused by the combination effect of the Schmid factor of dominated slip system and the dislocation mechanism.