Experimental investigation and thermodynamic modeling of the ZrO2–MnOx system

Solid state phase equilibria of the ZrO2–MnOx system as well as the equilibria including liquid were investigated at air and argon atmospheres in the whole compositional range using high temperature DTA, X-ray diffraction (XRD) and scanning electron microscopy combined with energy dispersive X-ray spectroscopy (SEM/EDX). The influence of the oxygen partial pressure on solubility of Mn in the c-ZrO2 phase, on the c-ZrO2 low temperature limit as well as on the L ⇄ c-ZrO2 + MnOx eutectic composition was shown. The thermodynamic parameters of the liquid phase as well as of the ZrO2 solid solutions were assessed by CALPHAD method using the obtained experimental results. The calculated phase diagrams of the ZrO2–MnO system at air (0.21 bar) and Ar (1·10−4 bar) conditions were compared with the experimental results obtained in this work and those available in the literature. The calculated results were found to be in reasonable agreement with the experimental data.