Influence of mechanical milling on the SiC particulate size in an Al-SiC composite

Particle reinforced aluminum-matrix composites are particularly attractive for the automobile and air-craft industries, due to their light weight, high strength, and good wear resistance. In the present work, silicon carbide (SiC) particulates have been incorporated into a pure Al matrix with the help of mechanical milling in a planetary ball-mill. Composite powders were prepared using both raw as well as premilled SiC powders. The effect of milling time on the SiC particulate size was investigated. Systematic analysis of x-ray diffraction data revealed a reinforcement particle size of about 30 nm in a composite containing 50 vol.% SiC. It has been observed that the size reduction occurs at a faster rate when indirect milling is used.