Prediction of thermodynamic and surface properties of ternary Ti–Si–Fe liquid alloy

Abstract

Thermodynamic and surface properties of the ternary Ti–Si–Fe liquid alloy have been assessed at temperatures 1873 K, 1973 K, 2073 K and 2173 K. For this purpose, the optimized linear temperature dependent coefficients of Redlich–Kister (R–K) polynomials for excess free energy of mixing for sub-binary systems Ti–Si, Fe–Si and Ti–Fe have been computed considering available experimental and literature data. The thermodynamic properties of ternary liquid alloy, such as activity have been studied using general solution model (GSM) and excess free energy of mixing has been studied using GSM, Kohler and Toop models. In surface properties, surface concentration has been computed using Butler’s equation and surface tension of the liquid alloy has been studied using all the four above mentioned models feeding the database of liquid Fe–Si, Si–Ti and Ti–Fe sub-binary systems. The values of surface tension computed using GSM and Toop model are in well agreement with each other at all concentrations. Moreover, the computed values of excess free energy of mixing and surface tension decrease at elevated temperatures from all corners and at all considered cross-sections indicating the decrease in ordering tendency of the alloy.