The Effect of MgCl2 Content on the Properties of Cordierite-Mullite Bonded Porous SiC Nano-Composites Produced by Reaction-Bonding Method

In this paper, the cordierite-mullite bonded porous SiC nano-composites were prepared by a reaction bonding method. For this reason, nano-SiC, talc and kaolin as raw materials, using graphite as the pore-forming agents were used for the preparation of these nano composites and then, the effect of MgCl2 addition on the properties of these nano-composites after firing at 1250 °C was investigated. Hence, the porosity and mechanical strength, thermal shock resistance, refractoriness under load, phase composition and microstructure of these nano composites were evaluated. The phase analysis results showed that cristobalite, corundum and magnesium aluminate spinel phases can form besides cordierite and mullite phases which, their contents depend on MgCl2 amount. The refractoriness of nano-composite improves with increasing of MgCl2 amount but, the nano-composite containing 2 wt.% MgCl2 has the highest thermal shock resistance. The microstructural investigations showed that a proper cordierite-mullite bonding was formed between nano-SiC particles.