二元铝锂合金析出相错配度的第一性原理计算  

First principles calculation of lattice misfit of binary Al-Li precipitates

作　　者：梁超平[1] 王飞龙[1] 唐赛 刘文胜[1] 马运柱[1] LIANG Chao-ping;WANG Fei-long;TANG Sai;LIU Wen-sheng;MA Yun-zhu(National Key Laboratory of Science and Technology for High-Strength Structural Materials,Central South University,Changsha 410083,China)

机构地区：[1]中南大学轻质高强结构材料国家级重点实验室,长沙410083

出　　处：《中国有色金属学报》2023年第1期68-77,共10页The Chinese Journal of Nonferrous Metals

基　　金：国家自然科学基金资助项目(51801236,51801237)。

摘　　要：通过第一性原理计算结合准谐德拜模型系统研究了热膨胀系数、固溶度和空位浓度对Al/Al_(3)Li和Al/AlLi晶格错配度的影响规律,发现Al/Al_(3)Li晶格错配主要源于有序■无序相转变和热膨胀系数差异,而Al/AlLi的错配,除了晶体结构外,主要受两相中锂固溶成分的影响。通过与实验析出相的尺寸比较得出Al/Al_(3)Li之间为共格相界,而Al/AlLi为非共格相界。对热膨胀系数、固溶度和空位浓度的分析不仅确定了晶格错配的起源,而且也为相关实验现象提供了理论解释。The effects of thermal expansion, solid solubility and vacancy on the lattice misfit of Al/Al_(3)Li and Al/AlLi were investigated by first-principles calculations with the help of quasi-harmonic Debye model. The results show that the lattice misfit of Al/Al_(3)Li originates mainly from the order-disorder phase transition and thermal expansion, while the misfit of Al/AlLi is mainly affected by the lithium centration and the different crystal structure. Compared with the experimental precipitates size, it is found that Al/Al_(3)Li interphase boundary is coherent, while Al/AlLi is incoherent. The detailed analysis of thermal expansion, solid solubility and vacancy concentration not only unravels the origin of lattice misfits, but also provides the theoretical explanation for related experimental phenomena.

关 键 词：第一性原理计算 铝合金 析出相 晶格错配 

分 类 号：TG131[一般工业技术—材料科学与工程]