Preparation of SiC Ceramics from Charcoal

Abstract

Charcoal has been recognized as new carbon resource because it is reproducible and good for earth resource drain and environmental problems. For production of SiC ceramics, in the present study, charcoal was utilized as a carbon source. In order to examine the usefulness of charcoal powder, three kinds of carbon, charcoal, carbon black and graphite were used for the reaction of SiC formation and the reactivity with silicon was investigated. SiC from charcoal had good crystallinity. Charcoal powder showed better reactivity with silicon due to the characteristic porous structure. Charcoal was found to become carbon source for ceramics production. Porous SiC was prepared utilizing the characteristic structure of charcoal by Si-infiltration technique. The infiltration was carried out at 1450°C for 2h under a flow of Ar gas. Obtained specimen was almost reacted to SiC but a little bit of silicon was observed via XRD. However, the characteristic structure of charcoal was maintained after the reaction with Si. The mechanical properties of the porous SiC materials were improved compared with as-received charcoal.