New approach for β -SiC powder synthesis by combustion method

Abstract

The effect of KClO₃+3Mg additive concentration on the combustion ability of Si+C ‘weekly exothermic’ mixture has been studied. The critical concentration of KClO₃+3Mg mixture for combustion to occur has been found to be 0·02 mol. The morphological and structural characteristics of products have been investigated as a function of the additive concentration, reaction pressure and the initial sample diameter. The reaction products have been analysed by X-ray diffraction, scanning electron microscopy and BET surface area analysis methods. It has been shown that β-SiC hollow globules composed of submicrometre size particles have been formed during the combustion reaction. After leaching and grinding of final products ultrafine and single phase β-SiC powders with particles size less than 0·5 μm, and specific surface area of 18·5 m² g^–1 have been synthesised.