Pore size control of Al2O3 ceramics using two-step sintering

Porous Al2O3 ceramics were prepared using a two-step sintering method. Green bodies were prepared using the slip cast method. The average pore size and porosity of the obtained samples were, respectively, 73 nm and 42%. The porosities and the average pore size of the samples prepared using a one-step sintering method decreased concomitantly with increasing sintering temperature. The porosity was mostly constant at temperatures higher than 1300 °C. The T1 and T2 temperatures were set, respectively as 1150 °C and 1000 °C for two-step sintering tests. Under these conditions, the pore size was controllable by sintering time without porosity change. The average pore size of the obtained samples was 61–76 nm without porosity change.