Effect of alumina addition on initial sintering of cubic ZrO2 (8YSZ)

The effect of 0-10 wt% alumina addition on the initial sintering of 8 mol% Y2O3 cubic ZrO2 (8YSZ) was studied. Activation energy and initial stage of sintering mechanism were analyzed in order to understand the effect of the alumina in the sintering process. The analysis was carried out using the analytical method for constant rate heating (CRH). The activation energy decreased from 716 to 599 kJ/mol for undoped 8YSZ to 2.16 wt% of alumina-8YSZ, respectively. The mechanism for the initial stage of sintering for <2.16% Alumina-8YSZ changed from grain boundary diffusion (GBD) to volumetric diffusion (VD). With 10 wt% of alumina, the activation energy increased to 854 kJ/mol which was thought due to the change in the initial stage of sintering mechanism from VD to GBD.