三元合金及金属间化合物中各组分活度系数的计算

Calculation of activity cofficients for components in ternary alloys and intermetallics

根据 Kohler三元溶体模型和 Miedema二元系统生成热模型 ,建立了计算三元合金及金属间化合物中各组分活度系数的方程 .计算了三元合金 Ti-5Al-2 .5Sn、Ti-6Al-4 V及不同温度下金属间化合物 Ti Al、Ti3 Al和 Ti2 Al Nb中各组分的活度系数 .并与有关实验值进行了对比 .计算结果表明此公式的计算结果与实验值吻合较好 ,解决了固态二元、三元合金及金属间化合物中各组分的活度系数的计算问题 .Ti与 Al活度系数均小于 1 ,对Raoult定律产生负偏差 .根据所计算的活度系数和活度值 ,预测了 Si C/ Ti Al、Si C/ Ti3 Al和 Si C/ Ti2 Al Nb复合材料的界面反应 ,表明 Si C/ Ti3

Based on Kohler's ternary solution model and Miedema's model for calculating the heat of formation of binary solution, the integral equation has been established for calculating the activity coefficients in ternary alloys and intermetallics. The activity coefficients for components in ternary alloy Ti-5Al-2.5Sn? Ti-6Al-4V and intermetallics TiAl, Ti 3Al and Ti 2AlNb have been calculated with the equation and compared with experimental data in literatures. The results show that calculation values of activity coefficients coincide with experiment value ,solving calculation problem of activity coefficients in ternary alloys and intermetallics at solid state. Activity coefficients of Ti and Al are less than 1, indicating a negative deviation from Raoult law. According to the calculated activity coefficients and activities, it can be predicted that the interfacial reaction in SiC/ Ti 3Al composite is more severe than in composites SiC/Ti 2AlNb and SiC/TiAl.