Tensile ductility in zirconia-dispersed alumina at high temperatures

High-temperature plastic flow in Al2O3-10 wt% ZrO2 (2.5 mol% Y2O3) has been examined at temperatures between 1400 degrees and 1500 degrees C. Al2O3-10 wt% ZrO2 (2.5 mol% Y2O3) exhibits much higher flow stress and smaller tensile elongation below about 1450 degrees C than 0.1 wt% MgO-doped single-phase Al2O3. The suppression of grain growth with ZrO2 dispersion into Al2O3 is not effective for improving the tensile ductility. The limited ductility in Al2O3-10 wt% ZrO2 (2.5 mol% Y2O3) is associated with the Increment of flow stress caused by ZrO2. The ZrO2 dispersion or segregation in Al2O3/Al2O3 boundaries suppresses the grain boundary sliding and hence results in the increased flow stress at high temperatures.