Development of the sponge cast aluminum and its application to the slip casting mold

The sponge cast taluminums with mean pore size of 7, 13 and 20μm in diameter were produced by the process, i.e., pressure casting of molten aluminum into the NaCl particulate preform and then dissolving away the NaCl skeleton from the NaCl-aluminum composite. The study was undertaken to ascertain the feasibility of the sponge cast aluminum to apply to the slip casting mold for zirconia ceramics. Slip casting by using the sponge cast aluminum with 7μm pores could be carried out in the same way as slip casting by a conventional plaster mold. In the case of the sponge cast aluminum mold with larger pores, demolding of green was difficult without plaster coating on the mold surface, and the greens were soft as compared with those by the plaster mold. Differences of bulk density and bending strength between the specimens obtained by the sponge cast aluminum molds and those by plaster molds were not detected.