Mg-Ca系合金结构和力学性质的第一性原理研究

First Principles of Structure and Mechanical Property of Mg-Ca Series Alloy

通过基于密度泛函理论的第一性原理计算方法,分析了Mg-Ca、Mg-Ca-X（X=Al,Sr）等二元和三元合金的结构和力学性质。结果表明：Mg_2Ca合金为二元Mg-Ca合金的最稳定相。Mg_2Al_6Ca_4为合金形成能力最强且最稳定的合金相,其次是Mg_6Al_2Ca_4和Mg_6Ca_4Sr_2,Mg_2Ca_4Sr_6为不稳定相。Mg2Al6Ca4存在最强的抗外力变形能力、抗剪切变形能力和刚度,而Mg_6Ca_4Sr_2的塑性和延展性最强。

The structure and mechanical property of Mg-Ca and Mg-Ca-X （X =Al, Sr） alloy were analyzed by first principles calculations based on density functional theory. The results show that Mg2Ca alloy is the most stable phase for Mg-Ca binary alloy. Mg2Al6Ca4 has the strongest alloying forming ability, which is the most stable alloying phase, then the next is Mg6Al2Ca4 and Mg6Ca4Sr2, and Mg2Ca4Sr6 is an unstable phase. Mg2Al6Ca4 has the best external deformation resistance, shear deformation resistance and stiffness. Then, Mg6Ca4Sr2 has the best plasticity and ductility.