Search

In this work, the experiments were carried out to investigate the evaporation kinetics of Zn in Bi–Zn and Bi–Sn–Zn systems under vacuum distillation. The evaporation rate of Zn in Bi–Zn and Bi–Sn–Zn systems were measured at pressure of 10 Pa. The activity coefficients of Zn for these two systems were modelled by the T–K-Wilson (Tsuboka–Katayama modified Wilson) equation. There is satisfactory agreement between the experimental results and the model calculations. The evaporation coefficients and evaporation rates of metal elements under vacuum conditions were obtained based on the Langmuir equation. The range of evaporation coefficients in the systems were determined. The results show that the evaporation ratio increases with increasing the temperature. The experimental and calculated evaporation rates of Zn in binary and ternary systems were discussed. In addition, the activation energies of Zn for the Bi–Zn and Bi–Sn–Zn alloys were calculated.