Vapor-liquid equilibria (VLE) of the Cu–Sn system have been investigated in the temperature range from 1612 to 1650 K and at pressure of 5 Pa. The VLE data of Cu–Sn alloy was calculated by using Wilson equation and compared with experimental values under vacuum condition. The thermodynamic consistency of the experimental data was checked by Van Ness method. The azeotropic and non-azeotropic regions are plotted by correlating the Wilson equation, vapor pressure equation and the enthalpies of vaporization. The calculated results reveal that the Cu–Sn system is located in azeotropic region which the specific composition and temperature of azeotropic point are $x_{Cu}=0.71$ and $T=1649K$. The agreements between calculated and measured results are good. This work provides an effectively method for predicting whether binary system will form an azeotrope or not and the azeoropic position in vacuum distillation. It can also be used to test the quality of a vapor-liquid equilibrium model and to guide experiments.

在1612至1650 K的温度范围和5 Pa的压力下，研究了Cu-Sn系统的气液平衡（VLE）。使用Wilson方程计算了Cu-Sn合金的VLE数据，并与实验进行了比较。真空条件下的数值。实验数据的热力学一致性通过范尼斯方法进行了检查。通过将Wilson方程，蒸气压方程和汽化焓相关联，绘制出共沸和非共沸区域。计算结果表明，Cu-Sn体系位于共沸区域，共沸点的具体组成和温度为$X_{Cü}=0.71$ 和 $Ť=1649ķ$。计算结果与测量结果之间的一致性很好。这项工作为预测二元体系是否会形成共沸物以及真空蒸馏中的共沸位置提供了有效的方法。它也可用于测试气液平衡模型的质量并指导实验。