Abstract
ZrO2 porous ceramic was prepared by a unidirectional freeze casting using aqueous slurries containing urethane latex binder. The effects of solid loading, binder content and cooling rate on the pore size distributions of sintered bodies were investigate by scanning electron microscopy and mercury intrusion porosimetry. Porous ZrO2 ceramic with continuously long-ranged pore structure was obtained by the unidirectional freezing of the aqueous ZrO2 slurry, followed by sublimation of ice and firing at 1400°C for 1h in air. The solid loading of the slurry scarcely affected the pore size of sintered bodies. However, the pore volume decreased and the thickness of pore wall increased with increasing solid content in the slurry. Binder content largely influenced the strength of green bodies. At low binder content, green bodies became weaker, and therefore many cracks were generated bodies. The effect of cooling rate on the sintered body was small, but pore size decreased with increasing cooling rate. These results show that the pore size and volume can be controlled by modifying the cooling rate of the slurries and slurry concentration.
