Critical assessment and thermodynamic modeling of the binary Mg–Zn, Ca–Zn and ternary Mg–Ca–Zn systems

Critical assessment of the experimental data and re-optimization of the binary Mg–Zn, Ca–Zn systems and the Laves phase of the Mg–Ca system have been performed. A comprehensive thermodynamic database of the Mg–Ca–Zn ternary system is presented. All available as well as reliable experimental data both for the thermodynamic properties and phase boundaries are reproduced within experimental error limits. In the present assessment, the Modified Quasichemical Model in the pair approximation is used for the liquid phase to account for the presence of the short-range ordering properly. The intermediate solid solutions are modeled using the compound energy formalism. Since the literature included contradicting information regarding the ternary compounds in this system, thermodynamic modeling of phase equilibria is used to determine the most likely description of this system and to exclude the self-contradicting experimental observations.