A first-principles study on electronic structure and elastic properties of Al_4Sr, Mg_2Sr and Mg_(23)Sr_6 phases

Al_4Sr,Mg_2Sr和Mg_(23)Sr_6相的电子结构与弹性性能的第一原理研究(英文)

The electronic structures and mechanical properties of Al4Sr, Mg2Sr and Mg23Sr6 phases were determined by the use of first-principles calculations. The calculated heat of formation and cohesive energy indicate that Al4Sr has the strongest alloying ability as well as the highest structural stability. The elastic parameters were calculated, and then the bulk modulus, shear modulus, elastic modulus and Poisson ratio were derived. The ductility and plasticity were discussed. The results show that Al4Sr and Mg2Sr phases both are ductile, on the contrary, Mg23Sr6 is brittle, and among the three phases, Mg2Sr is a phase with the best plasticity.

采用第一性原理计算Al4Sr,Mg2Sr和Mg23Sr6相的电子结构与弹性性能。合金形成热与结合能的计算结果显示Al4Sr具有最强的合金化形成能力和最高的结构稳定性。通过计算弹性常数、体模量、剪切模量、弹性模量和泊松比,讨论了体系的韧性与塑性行为。结果表明,Al4Sr和Mg2Sr为延性相,Mg23Sr6为脆性相,在3种金属间化合物中,Mg2Sr的塑性最好。