Control of the tetragonal-to-monoclinic phase transformation of yttria partially stabilized zirconia in hot water

The tetragonal-to-monoclinic phase transformation of yttria partially stabilized zirconia caused by annealing in hot water was investigated in the temperature range 80 to 200° C using sintered bodies in zirconia containing 2, 3 and 4 mol % Y2O3. Three approaches, alloying ZrO2(Y2O3) with 0 to 20wt% CeO2, dispersing 0 to 40 wt % Al2O3 into ZrO2(Y2O3) ceramics and decreasing the grain size of zirconia, were examined to inhibit the tetragonal-to-monoclinic phase transformation. The amount of monoclinic phase formed decreased with increasing concentrations of CeO2 alloyed and Al2O3 dispersed, and with decreasing grain size of zirconia.