Thermodynamic calculation of the Mg-Mn-Zn and Mg-Mn-Ce systems and re-optimization of their constitutive binaries

The Mg-Mn-Ce and Mg-Mn-Zn ternary systems are modeled using the CALPHAD approach. Each constituent binary is critically reviewed in light of available experimental information. Consequently, binaries are re-optimized or directly adopted from the literature. All the binary liquids in the present optimization are modeled by the modified quasi-chemical model (MQM) while the random mixing model is used to describe the terminal solid solutions. The sub-lattice model is applied to the compounds with well-defined solubility range in contrast to the stoichiometric phases which are described as line compounds. Binaries are then extrapolated to form the ternaries without adding any ternary parameters. Very little experimental data is available on these two systems. Nonetheless, the present optimization reproduces most of experimental findings on these binaries as well as ternary systems with reasonable accuracy. Incorporation of future experimental data, as and when available, will refine the present optimization.