Fabrication and microstructural characterization of porous silicon carbide with nano-sized powders

Porous silicon carbide was fabricated by using nano-sized SiC powder additions and different cold isostatic pressing (CIP) conditions followed by sintering at 1500–1800 °C. The relationship between the processing conditions, pore size and microstructure was examined. The cold isostatic pressing conditions, sintering temperature and nano-sized additives were effective for controlling pore size and microstructure. The pore size and particle size increased with increasing sintering temperature, attributed to surface diffusion. However, no densification occurred because of pore enlargement. In addition, the compressive strength increased with sintering temperature and reached values as high as 513 MPa. This was due to the formation of well-developed neck areas. This study suggests that the promoted mass transfer can provide high strength due to increased neck area.