OXIDATION BEHAVIOUR OF SILICON CARBIDE : GEL DERIVED OXIDE COMPOSITE SYSTEMS

Consolidation of composites in the system SiC—Al2O3, SiC—ZrO2 and SiC—MgO in relation to oxidation characteristics of silicon carbide during firing in the ambient atmosphere were studied. A12O3, ZrO2 and MgO additives were derived through sol-gel route. SiC—Al2O3 system was found to be more resistant towards oxidation of SiC where ultimate fired phases were silicon carbide and mullite with traces of cristobalite as detected by XRD. Both Al2O3, and ZrO2 are prospective, but MgO in the present system is not effective.