Phase diagram of the system: ZrO2–Cr2O3

The ZrO2–Cr2O3 system was studied by differential thermal analysis in the composition range from 0 to 40 mass% Cr2O3. The formation of extensive solid solutions (25 mass% Cr2O3 in cubic zirconia and 40 mass% ZrO2 in Cr2O3 at the eutectic temperature) and the eutectic point coordinate: 1950°C and 50 mass% of ZrO2 are reported. Cubic zirconia solid solution decomposes at 1840°C, 25 mass% Cr2O3, by eutectoid reaction forming tetragonal zirconia solid solution with 9 mass% Cr2O3. This phase transforms at 1115°C to monoclinic zirconia solid solution. The enthalpies of these transformations are: 610±60 J/g for eutectic fusion, 110±10 J/g for eutectoid at 1840°C, 25 mass% Cr2O3, 22±5 J/g for eutectoid at 1115°C, 9 mass% Cr2O3 and 42±5 J/g for pure zirconia at 1165°C.