Investigation of key Parameters on the Properties of Cordierite Bonded Porous SiC Composites Produced by Reaction-Bonding Method

In this paper، the cordierite bonded porous SiC composites were prepared by a reaction bonding method. For this reason، SiC، talc and kaolin as raw materials، using graphite and poly urethane sponge as the pore-forming agents were used for the preparation of these composites. The effects of raw materials type and content، silicon carbide content and type and content of pore-forming agent on the properties of these composites after firing at 1250 °C were investigated. Hence، the physical and mechanical properties، thermal shock resistance، refractoriness under load، phase composition and microstructure of these composites were evaluated. The results showed that raw materials type and composition have effects on the formation of cordierite phase drastically. The cristobalite، corundum، primary and secondary mullite phases can form in composite besides of cordierite which their contents depend on raw materials and silicon carbide content. Besides، type and content of pore-forming agent have a great effect on the mechanical strength of these composites. The best results were obtained with composition containing 30 wt. % graphite and 60 wt. % silicon carbide. The microstructural investigations showed that a proper cordierite-mullite bonding was formed between silicon carbide particles.