Thermodynamics and vacuum distillation studies of liquid Al-Ga and In-Sn alloys

Activities of components in liquid Al-Ga and In-Sn alloys, the separation coefficients and vapour-liquid phase equilibrium in vacuum distillation were predicted using the molecular interaction volume model as a function of the activity coefficients. The results indicated that both Al and In are preferentially volatilised into vapour phase while Ga and Sn remain in residue. Similarly, we found that both the mass fraction and the content of Al and In in vapour phase increase as distillation temperature increases such that when the content of Al is 0.005985wt% and In is 0.004141wt% in vapour phase, respectively, in liquid phase, it was 70wt% at T=1073K for both. The calculated values of activity and activity coefficients at various temperatures are presented. Comparison of the predicted values with experimental data indicates good agreement, thus verifying from statistical thermodynamics viewpoint that the model is stable and reliable.