Thermodynamic analysis of the Ni-Si-Ti system using thermochemical properties determined from Ab initio calculations

Abstract

A thermodynamic analysis has been carried out on the Ni-Si-Ti ternary system using the CALPHAD method. A regular solution approximation based on the sublattice model was adopted to describe the Gibbs energy for the individual phases in the binary and ternary systems. The thermodynamic parameters for each phase were evaluated using available experimental data on the phase boundaries and other related thermochemical properties. In addition to the experimental data, the enthalpy of formation for some binary and ternary compound phases as determined by ab initio calculations was incorporated in the present analysis. There was good agreement between the calculated and the experimental phase equilibria in the binary and ternary systems.