Kinetics of carbothermal reduction synthesis of beta silicon carbide

Abstract

Abstract Carbothermal reduction kinetics to synthesize SiC is studied under conditions of high carbon/silica precursor heating rates (10 5 K/s) and minimized reaction times (s) over a wide temperature range (1,848⩽T⩽2,273 K). The reaction mechanism includes rapid formation of a gaseous SiO intermediate. Further carbon reduction of the SiO to SiC is reaction‐rate‐controlling. Carbon crystallite diameter, d, has a substantial influence on the rate of reaction and the size of synthesized SiC. Fractional oxide conversion, X, can be described by a contracting volume shrinking core model: where k 0 = 27.4 m/s and E = 382±34 kJ/mol.