Thermodynamic and surface properties of Al-Li-Mg liquid alloy

The thermodynamic database of excess Gibbs free energy of mixing was theoretically reproduced at temperatures 1000 K, 1073 K 1150 K, and 1250 K for liquid Al-Li-Mg ternary alloy on the basis of GSM, Toop and Kohler models. For this purpose, the linear as well exponential T-dependent interaction parameters of Redlich-Kister (R-K) polynomials were optimised. These parameters were used to compute the activities of the monomers of the binary sub-systems. The enthalpy of mixing of the ternary system was computed using exponential T-dependent parameters. The surface tensions of binary sub-systems were calculated employing Butler's equations and using the theoretically determined partial excess Gibbs free energy of constituent elements of the alloy. Further, the optimised coefficients of R-K polynomials were obtained for excess surface tensions of binary subsystems. With the aid of these coefficients, the surface tension of the ternary system was computed in the frame work of models mentioned above.