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.