Synthesis and characterization of silicon carbide by reaction milling in a dual-drive planetary mill

Abstract

The formation of silicon carbide from elemental silicon and graphite powder by reaction milling in a specially designed dual-drive planetary mill is reported. The phase evolutions, particle size distribution, and morphology of particles during milling are studied during a 40-h grinding period. X-ray diffraction study indicates complete conversion of silicon and graphite to silicon carbide. The crystallite size varies from 150 nm from the start to 10 nm after 40 h of milling. The lattice strain increases with milling up to about 20 h when SiC forms and subsequently with the formation of SiC it is reduced.

Al–SiC composites are prepared by mixing Al with 40 h milled final SiC powder and sintered in an inert atmosphere. The composites show excellent compatibility between Al and SiC particles, no voids or cracks are present.