α-Fe中刃型位错与空洞相互作用的分子动力学模拟

Molecular dynamics simulation of interaction between edge dislocation and void in α-Fe

本文通过分子动力学方法(MD),采用嵌入原子势法(EAM),沿[111]方向插入一层(011)半原子面形成位错,然后在模型中插入空洞,模拟了BCC铁中刃型位错与空洞相互作用,研究了空洞对位错运动的影响机理.模拟结果表明,当温度设定为10 K时,位错运动速度快,但空洞直径的大小对位错运动速度的影响不太明显,当高温设定为100 K时,由于位错线密度增大并随着空洞直径的增加位错运动速度减小,临界剪切应力也随着减小.最后将模拟计算结果与Osetsky的研究数据及连续体理论模型进行了对比分析.

In this paper, the interaction of edge dislocation with void has been simulated by using the mo- lecular dynamics（MD） method and the embedded atom method （EAM）inserting one（011）hemi-atom plane along the[Ill]orientation. Also, the reaction mechanism of void to dislocation motion has been studied. The results show that at T~ 10 K the dislocation speed is fast and the increase of void diameter has no obvious reaction to dislocation speed however, at T=100 K, the dislocation speed and the criti- cal resolved shear stress decrease with the increasing void diameter because of the increase at dislocation density. At last our results are compared with those of the former Osetsky＇s work and the continuum treatment.