Assessment of thermophysical properties of Al–Mg–Si liquid alloys

The linear and exponential temperature-dependent interaction parameters for excess Gibbs free energy of mixing of constituent binary subsystems in liquid Al–Mg–Si alloys were optimized using the framework of R–K polynomials. The optimized parameter were then used to estimate the excess Gibbs free energy of mixing and activity of the ternary system at 1100 K, 1200 K, 1300 K and 1400 K employing GSM, Kohler and Toop models. The surface tensions of the systems were calculated using Butler's equations. Kaptay's equation was used to calculate the viscosity of binary subsystems as well as ternary mixture employing the exponentially optimized coefficients of R–K polynomials. The optimized parameter were further used to compute the concentration fluctuation in long wavelength limit for Al–Mg–Si alloys.