Porosity and pore space characteristics of starch-processed porous ceramics

In this paper we report on new results of a comparative study concerning the microstructure of porous alumina ceramics prepared from starch-containing ceramic suspensions by slip casting into plaster molds and from identical suspensions by starch consolidation casting (SCC) into metal molds. It is shown that a ceramic suspension prepared with 10 vol% starch results in a porous ceramic body with approx. 10% closed porosity (as expected) when the bodies are prepared by traditional slip-casting, whereas the same suspension results in a ceramic with more than 25% porosity (essentially open), when the bodies are prepared via SCC.