Thermodynamic optimization and phase equilibria study of the MgO-ZnO, CaO-ZnO, and CaO-MgO-ZnO systems

The binary MgO-ZnO and CaO-ZnO systems and the ternary CaO-MgO-ZnO system were thermodynamically optimized with phase equilibria studies in this study. Bragg-Williams random mixing model was used for solid solutions, while Modified Quasichemical Model was used for liquid solution. The thermodynamic optimization was conducted using Factsage 8.1 thermochemical software. The optimized phase diagrams fit well with phase equilibria experimental results. The phase equilibria studies were performed for the MgO-ZnO systems at 600 degrees C, 650 degrees C, 700 degrees C, and 1000 degrees C, and for CaO-MgO-ZnO systems at 1500 degrees C, 1550 degrees C, and 1600 degrees C. Quenched samples were analyzed by SEM/EDS to confirm equilibrium phases. Liquid phases were newly observed in the CaO-MgO-ZnO systems at 1550 degrees C and 1600 degrees C.

Automated summary

Thermodynamic optimization was performed for the binary MgO-ZnO and CaO-ZnO systems and ternary CaO-MgO-ZnO system by studying phase equilibria. Bragg-Williams random mixing model and Modified Quasichemical Model were used for solid solutions and liquid solutions, respectively. The optimized phase diagrams matched well with experimental results of phase equilibria. Phase equilibria studies were conducted at various temperatures for MgO-ZnO and CaO-MgO-ZnO systems, and SEM/EDS analysis of quenched samples confirmed equilibrium phases. Liquid phases were newly observed at 1550 degrees C and 1600 degrees C in the CaO-MgO-ZnO system.