二元合金溶解度间隙的集团变分法分析

Analysis of Binary Alloy Miscibility Gap by Cluster Variation Method

应用集团变分法键近似理论,计算了原子间结合能 ε_(ij)为常数的二元合金溶解度间隙和失稳分解曲线,并就其最高临界温度 T_s 进行了理论分析。结果表明由集团变分法获得的T_s比用 Bragg-Williams 统计理论计算的临界温度低。这主要是因为集团变分法更精确地计算了溶体内能的缘故。

Binary alloy miscibility gap and Spinodal decomposition curves are calculated byvirtue of the pair approximation theory and Cluster Variation Method as the pair interaction ε_(ij) is assumed as constant. The critical temperature of the mis-cibility gap is then discussed theoretically on a basis of CV-pair approxima-tion. The results show that the critical temperature so determined is lowerthan that by Bragg-Williams approximation because the internal energy cal-culated by CVM provides higher accuracy.