Preparation of porous SiC ceramics from waste cotton linter by reactive liquid Si infiltration technique

Porous carbon and porous silicon carbide with homogenous microstructure are prepared from cotton linter and phenolic resin through mold-stacking, solidification, carbonization and liquid Si infiltration process. SEM observation reveals that the irregular interconnected pores of carbon preparation were originated from the random arrangement of cotton linter fiber and different carbonization shrinkage. After the liquid Si infiltration process, the porous carbon was converted into dense SiC/Si composites. The porous SiC was formed during the Si-removing process at higher temperature. The result shows that open porosity of porous silicon carbide increases as Si-removing time increase, while the bending strength and the fracture toughness decrease.