Thermodynamic and Surface Properties of Liquid Al-Cu-Ni Alloys

Using the available experimental and literature data, the linear temperature-dependent interaction parameters of liquid binary alloys, subsystems of the Al-Cu-Ni system in the Redlich–Kister (R–K) polynomial form were optimized. The activities of pure components of binary subsystems were then computed using optimized parameters and subsequently validated by available experimental and literature data. The thermodynamic database of the excess Gibbs free energy of mixing for the ternary system was theoretically reproduced for temperatures of 1773, 1873, 1973 and 2073 K, applying general solution model, Toop’s and Kohler’s geometric models. The goal of this effort is to develop a database of the thermodynamic and thermophysical properties of the system so that it can be conveniently used for future research. Indeed, employing Butler's equations with the partial excess Gibbs free energies as inputs, the surface tensions of binary subsystems were computed. Based on the aforementioned models, using the optimized coefficients of R–K polynomials for the excess surface tensions of binary subsystems, the surface tension of the ternary system was obtained.