孪晶界对α铁力学性能影响的模拟研究

采用分子动力学方法研究在单轴拉伸载荷下孪晶界间距和孪晶界与拉伸载荷角度对纳米孪晶铁力学行为的影响。结果表明:纳米孪晶铁的屈服强度随着孪晶界间距的增大而增大,呈现反常的Hall-Petch关系;单晶铁中出现变形孪晶,此时其塑性变形以变形孪晶为主;弹性模量随孪晶界间距增大有轻微的增大;拉伸载荷与孪晶界不垂直时,屈服应力降低,变形方式则以去孪晶为主。

Simulation of Effect of Twin boundary on Mechanical Property of α-Fe

The effects of twin boundary spacing and angle between loading axis and twin boundary on the mechanical behavior of nano-twinned Fe under the uniaxial tensile load were studied by molecular dynamic simulation. The results indicate that the yield stress of nano-twinned Fe increases with the increase of twin boundary spacing, showing a trend of inverse Hall-Petch relation. The deformation twin exhibits in the single crystal iron,which is predominant in the plastic deformation process. The elastic modulus of nano-twinned Fe increases slightly with the increase of twin boundary spacing. When the tensile load is not perpendicular to the twin boundary, the yield stress decreases and the deformation is mainly detwinning.