SiC honeycomb ceramics with parallel channels and macroporous walls were prepared by combining extrusion molding with pressureless sintering technology in the presence of starch. The extrusion molding constructed honeycomb structure with parallel channels, while the starch formed spherical macropores on the channel walls. The density and bending strength of SiC honeycomb ceramics decreased with the increase of starch content, while the phase compositions did not vary with the starch content. The control in starch addition could adjust the pore structures on the channel walls of SiC honeycomb ceramics.

Bamboo charcoal was expected to be a renewable carbon source for carbide materials in carbothermal reduction because of its superior characteristics. SiC powders with characteristic shapes were fabricated by carbothermal reduction with industrial silica sol and bamboo charcoal particles as silicon and carbon sources respectively, and the effects of reacting temperature and time on shape evolutions and properties of the as-prepared SiC powders were investigated. The silica sol/bamboo charcoal system was firstly transformed into SiO₂/C system by the transition of silica sol and graphitization of bamboo charcoal, and the carbothermal reduction between SiO₂ and C occurred at/above 1600 ℃. The characteristic shapes of SiC particles were transformed from string-beads-like to dumbbell-like and rod-like with the increase of reacting temperature. The prepared SiC powders are expected to become new raw material for silicon carbide ceramic composites.