锡基三元液态合金组元活度预测的比较研究

Comparative Study on Component Activity Predication in Sn-Based Ternary Liquid Alloys

采用正规溶液模型(RSM)、亚正规溶液模型(SRSM)和分子相互作用体积模型(MIVM)的无限稀活度系数与二元模型参数的关联式,直接确定相应的模型参数.据此,预测了8个锡基三元液态合金Sn-Ag-Bi、Sn-Ag-In、Sn-Ag-Zn、Sn-Bi-Cu、Sn-Cu-Zn、Sn-Ga-Zn、Sn-In-Zn和Sn-Mg-Zn的组元活度,并与对应的实验值比较.预测结果为:RSM、SRSM和MIVM的预测平均标准偏差分别为0.071 6、0.071 9和0.018 3,平均相对误差分别为26%、29%和6%.这表明MIVM的预测效果与RSM和SRSM比较,具有较好的稳定性和可靠性,更接近于这些锡基三元液态合金.因此,应用MIVM预测的结果可以作为含锡液态合金热力学及其相平衡研究的参考数据.

The corresponding model parameters are determined by the relative formula between the infinite dilution activity coefficients and binary model parameters through the method of regular solution model （ RSM）, sub -regular solution model （SRSM） and molecular interaction volume model （MIVM） respectively. Accordingly, the activities of each component in eight Sn - based ternary liquid alloys, namely Sn - Ag - Bi, Sn - Ag - In, Sn - Ag - Zn, Sn - Bi - Cu, Sn - Cu - Zn, Sn - Ga - Zn, Sn - In - Zn and Sn - Mg - Zn, are predicted and the comparison between the predicted values and their corresponding experimental ones is provided. The results show that average standard deviations of RSM, SRSM and MIVM are 0. 071 6,0. 071 9 and 0. 018 3 respectively, and that the average relative errors are 26%, 29% and 6% separately, which indicate that MIVM, compared with the RSM and SRSM, is of greater stability and reliability so that it is of better similarity with real Sn - based ternary liquid alloys. Therefore, the values predicted by MIVM are reliable enough to be used as reference data in the research field of thermodynamics and its phase equilibrium in Tin liquid alloy.