Thermodynamic description of the ZrO2-TiO2-Al2O3 system based on experimental data

Phase relations in the system ZrO2-TiO2-Al2O3 have been investigated in the temperature range between 1557 and 1897 K using equilibration method. X-ray powder diffraction (XRD) and scanning electron microscopy combined with energy dispersive X-ray spectroscopy (SEM/EDX) have been used for sample characterization. Melting relations and sub-solidus reactions have been investigated using differential thermal analysis (DTA). Two invariant reactions are found at the subsolidus temperatures of 1593 and 1648 K. Three eutectic reactions have been established in the system based on microstructure investigation. Temperatures of these reactions were in the range between 1909 and 1978 K. Based on the obtained experimental results thermodynamic parameters of the system have been assessed. Isothermal sections and liquidus surface of the ZrO2-TiO2-Al2O3 system have been calculated.