FCC无序合金混合能的第一性原理计算及CALPHAD三元外推模型的比较

First-principles Calculation of Mixing Energy of FCC Disordered Alloys and Comparison of CALPHAD Ternary Extrapolation Models

通过建立特殊准随机结构(SQS),采用第一性原理VASP程序,分别对fccCo-Ni-X(X=Al,Cr,Re)三元无序合金及其相应子二元合金进行了第一性原理计算。通过Matlab软件,分别采用Muggianu模型、Kohler模型、Toop模型与Chou模型,将SQS计算所得二元系混合能外推得到三元合金的混合能曲线,并与第一性原理计算结果进行比较。结果表明:通过Chou模型外推得到的三元合金的混合能与第一性原理计算值吻合得最好,对于三元系甚至多元系热力学性质的外推,Chou模型能够得到更加合理准确的结果。

By establishing the special quasirandom structures (SQS), fcc Co-Ni-X (X =Al, Cr, Re) ternary disordered alloys and their binary ones were calculated by the first-principles calculation program-VASP. By using Matlab software, the mixing energy for ternary alloys extrapolated from their constituent binary SQS results by Muggianu model, Kohler model, Toop model and Chou model were compared with the first-principles calculation data. It was found that the mixing energy for ternary alloys extrapolated by Chou model agreed well with the calculated values of the first-principles. For extrapolation of thermodynamic properties for ternary and even multicomponent systems, the Chou model could obtain more reasonable and accurate results.