Al3Li相反位缺陷演化的微观相场模拟

Microscopic Phase-Field Simulation of Antisite Defect Evolution of Al3Li Phase

摘要:

基于离散格点形式的微扩散方程（Langevin方程），模拟了Al3Li相反位缺陷随时间的演化特征及随组元浓度、温度的变化规律。结果表明，Al3Li相中主要以Al原子占据Li位形成的反位缺陷AlLi为主，同时存在少量的Li原子占据Al位形成的反位缺陷LiAl，2种反位缺陷浓度均随温度的升高而上升，且AlLi远大于LiAl上升速率；随Li浓度的增加，AlLi浓度缓慢降低，LiAl浓度略有上升，但仍远远小于AlLi浓度；浓度变化对反位缺陷的影响远不及温度对其影响大。

Abstract:

Based on the microscopic phase-field dynamic diffusion equation (the Langevin equation), the effects of concentration and temperature on the antisite defect evolution in Al3Li phase are investigated. The results show that the main antisite defect in Al3Li phase is AlLi, in which the Li sites are taken by Al atoms; there also exists a little amount of LiAl, in which the Al sites are taken by Li atoms. The two antisite defects are all increase with the increase of temperature, and the rising rate for AlLi is far larger than for LiAl. With the increase of Li concentration, the AlLi concentration decreases slowly and the LiAl concentration increases slightly, but still far less than the AlLi concentration . It is found that the effects of temperature on the antisite defects are more obvious than the concentration.