Phase relations in the ZrO2-Nd2O3-Y2O3-Al2O3 system: Experimental study and thermodynamic modeling

The Nd2O3-Al2O3 and ZrO2-Nd2O3-Al2O3 systems were simultaneously re-assessed to reproduce experimental data from present study and literature. Phase relations in the Nd2O3-Y2O3-Al2O3 system were investigated by XRD, electron microscopy and DTA for the first time. Invariant reaction in solid phases B + YAM = NdAlO3 + C was determined to occur at 1863 K. The eutectic reaction liquid = YAG + NdAlO3 + Al2O3 was determined to occur at 2042 K and composition Al2O3-10 mol.% Nd2O3-13 mol.% Y2O3. The obtained data were used to assess thermodynamic parameters of this system. Isothermal sections were calculated in the range 1523-1923 K. Liquidus surface of the Nd2O3-Y2O3-Al2O3 system was calculated. The derived databases were combined with already available descriptions of the ZrO2-Nd2O3-Y2O3 and ZrO2-Y2O3-Al2O3 systems into four-oxide database.