Fabrication and Characterization of Near-Net-Shape In Situ Reaction-Bonded Porous Cordierite/SiC Ceramics

Porous cordierite/SiC ceramics were fabricated by in situ reaction bonding using alpha-SiC, alpha-Al2O3, and MgO powders as the starting materials. During sintering, part SiC is oxidized to SiO2 and then the latter reacts with Al2O3 and MgO to form cordierite. As a result, porous cordierite/SiC ceramics were obtained, and the ceramics are strengthened by the residual SiC. Due to the large volume expansion introduced by the oxidation of SiC, the ceramics exhibit small sintering-induced dimension variations. In addition, a fine-grained microstructure and good thermal and mechanical properties were obtained for the porous cordierite/SiC ceramics.