Phase Relationships at 1673 K and Thermodynamic Evaluation of ZrO2–SrO–CaO System

Twelve samples of the ZrO2-SrO-CaO system were prepared, quenched from 1673 K to room temperature, and characterized by XRD and SEM/EDS methods to investigate the phase relations of the ZrO2-SrO-CaO system at 1673 K. The results showed that four solid solution phases exist: (Sr, Ca)ZrO3, (Sr, Ca)2ZrO4, (Sr, Ca)3Zr2O7 and (Sr, Ca)4Zr3O10. Based on the experiments as well as the literature data, the ZrO2-SrO-CaO system was evaluated by the CALPHAD (CALculation of PHAse Diagram) method, and the isothermal sections at 1673 K and 2073 K and a liquidus projection were calculated. The calculation results were in good agreement with most of experimental results, which proves that the database is self-consistent and reliable, and this work can be applied to the design of novel refractories.