Thermodynamic modeling of the Mg–Al–Sb system

Abstract

Thermodynamic modeling of the Mg–Al–Sb system is carried out for the first time in this work. Among the constituent binaries in this system, only the Al–Sb and Mg–Sb are re-optimized. Liquid phases are described by the Redlich–Kister polynomial model, whereas the high temperature modification of Mg 3Sb 2 compound in the Mg–Sb system is described by the sublattice model. The constructed database is used to calculate and predict thermodynamic properties, binary phase diagrams of Al–Sb and Mg–Sb, and liquidus projections of the ternary Mg–Al–Sb. The calculated phase diagrams and the thermodynamic properties such as enthalpy, entropy, Gibbs free energy of mixing, and activities are found to be in good agreement with the experimental data from the literature. The established Mg–Al–Sb database predicted a closed ternary liquid miscibility gap, six ternary eutectics, two ternary peritectics, four saddle points and a critical point.