Porous SiC Ceramics with Controlled Pores by CVI and Oxidation Consumption Processing

Preparation of porous SiC ceramics with controlled pores is demonstrated by oxidation consumption of a chemical vapor infiltration (CVI) C/SiC composite. The results show that the pores formation can be well monitored by thermogravimetric analysis during the oxidation. Performing the oxidation at 800°C is more favorable for obtaining porous ceramic by carbon oxidation consumption. The pores in the prepared SiC porous ceramics are uniform and maintain the same size and shapes with the used carbon fibers. Effective protections of the carbon fibers during CVI as well as negligible following oxidation of SiC are reasons for the pores control. The novelty of the present work is to provide a relative simple method for preparation of porous SiC body with controlled pores as well as for preparation of complex-shaped porous SiC body.