Phase equilibria in the TiO2–YO1.5–ZrO2 system

Isothermal sections of the TiO2–YO1.5–ZrO2 phase diagram at 1300, 1500 and 1600 °C were studied experimentally using pre-alloyed powders prepared by reverse co-precipitation. The thermodynamic parameters for the TiO2–YO1.5 and TiO2–ZrO2 binaries were derived from literature data and combined with the recently determined thermodynamic database for the YO1.5–ZrO2 binary to develop a thermodynamic description of the TiO2–YO1.5–ZrO2 system. Ternary isothermal sections were calculated between 1200 and 1700 °C and agree well with the experimental evidence. A corollary result of this study is a revised phase diagram for the TiO2–YO1.5 binary.