Thermodynamic investigation of liquid properties of the Ni–Sn–Ti ternary system using CALPHAD method and geometric models

Abstract

Predictions for the liquid Ni-Sn-Ti alloys thermodynamic properties (molar excess Gibbs energy) are presented. The calculations were performed in the temperature range 1000-2000 K. Geometric models (using data from the binary end-systems) were used and the respective calculated molar excess Gibbs energy values were compared to CALPHAD method assessments. The concentration dependences of the liquid phase thermodynamic properties along different vertical sections Sn:Ti, Ni:Ti and Ni:Sn were estimated. Ternary interaction parameters (L 0 , L 1 and L 2 ) of the liquid phase were determined using General solution (geometric) model from thermodynamic data of the binary end-systems (Ni-Sn, Ni-Ti, Sn-Ti). Ternary parameters exhibit values: L 0 = -70360.5 -0.263*T; L 1 = -113023 -11.574*T; L 2 = -131755 -17.101*T. Negative molar excess Gibbs energies were obtained by all models.