A thermodynamic study of phase equilibria in the Au-Sb-Sn solder system

To design and develop high-temperature solder alloys, the thermodynamic calculations of phase equilibria have been performed on the binary Au-Sb and ternary Au-Sb-Sn systems over the entire composition range. The Gibbs free energy of individual phases has been approximated using a subregular-solution model, and the thermodynamic parameters for each phase have been evaluated using available experimental information on phase boundaries and other related thermodynamic properties. The calculated phase diagrams and thermodynamic quantities of the Au-Sb binary system show good agreement with experimental data, and the liquidus projection and the vertical sections in the Au-Sb-Sn ternary system are well reproduced using assessed thermodynamic parameters derived in this work.