Processing of porous cordierite ceramics with controlled porosity

Porous cordierite ceramics with controlled porosity were fabricated via a reaction sintering using expandable microspheres as sacrificial templates and ceramics-filled polysiloxane as a precursor for cordierite ceramics. The influence of the sintering temperature, the template content, and the additive composition on the microstructure, porosity, and compressive strength has been investigated. The results showed that the template content, the sintering temperature, and the sintering additive composition have a significant effect on the porosity. By controlling the template content, the sintering temperature, and the sintering additive composition, it was possible to produce porous cordierite ceramics possessing a wide range of porosities ranging from 11% to 72%. The compressive strength was influenced by both the porosity and the additive composition. The compressive strength of the porous cordierite ceramics containing 6 mass% kaolin as a sintering additive was similar to 150 MPa at 35% porosity.