Al,Zn,Cu和Cd固溶于B2-MgLi本征特性的第一原理研究

First-principles study of the properties of Al,Zn,Cu and Cd doped B2-MgLi alloys

采用第一原理方法研究镁锂中间相化合物固溶体的本征特性,研究了Al,Zn,Cu和Cd固溶于B2-MgLi合金中形成Mg8Li7X固溶体及Mg4Li3X固溶体的态密度,并对其晶格常数、弹性模量、体模量与剪切模量之比B/G以及泊松比ν进行了计算.结果表明:固溶体晶格常数与合金原子半径的变化趋势相同,Al固溶于B2-MgLi合金中形成Mg8Li7Al固溶体热力学上是不稳定的,Zn和Cd固溶于B2-MgLi合金,合金的强度得到提高,但韧性和塑性降低;相反,Cu固溶于B2-MgLi合金,不利于合金强度的提高,但能增强合金的韧性和塑性.

The major mechanical and electronic properties of the Li,Zn,Cu and Cd doped the B2-MgLi alloys were investigated by employing the first principles density functional theory methods.The elastic parameters were evaluated,and the elastic modulus,Poisson＇s ratio（ν）and B/Gratio were further derived.The results show that the elastic parameters of the B2-MgLi solid solutions would increase along with increasing the atomic radii of alloying element.The Mg8Li7 Al alloys isn＇t mechanical stable.The strength of B2-MgLi alloy would improve by addition Zn and Cd alloying element,but decreases by addition Cu.