Combustion synthesis of SiC nanosized powders at low nitrogen pressure

Abstract

Combustion synthesis of β-silicon carbide (SiC) powders was accomplished at a nitrogen pressure lower than 2 MPa. The combination of mechanical activation and chemical stimulation was effective in enhancing the reactivity of Si powder reactants, which was responsible for the reduction in the minimum nitrogen pressure normally required for the combustion synthesis of SiC. Nanosized β-SiC powders with spherical particles were synthesised at nitrogen pressure as low as 1 MPa. The combustion synthesised SiC powders have a narrow particle size distribution in the range of 50–100 nm and could be hot pressed to 99·1% theoretical density with 10 wt-%Y2O3 and AlN as additives.