Superplasticity in cubic yttria stabilized zirconia with 10 wt.% alumina

The feasibility of superplasticity in 8 mol% cubic yttria stabilized zirconia (8Y-CSZ) containing a fine dispersion of alumina was investigated. Grain growth of 8Y-CSZ was limited by addition of 1–10 wt.% alumina. A fine grain size on the order of 1.1 μm was achieved with a dispersion of 10 wt.% alumina in 8Y-CSZ. Deformation tests under compression were conducted at temperatures from 1300 to 1450 °C for 8Y-CSZ with 10 wt.% alumina. Strain rates as high as 4×10−3 s−1 at 1450 °C were obtained, similar to the high strain rates observed for superplastic tetragonal yttria stabilized zirconia. The inverse grain-size exponent and the stress exponent both were calculated to be around 2 and the activation energy for high temperature deformation was calculated to be in the range of 597–683 kJ/mol.