Microstructural Evolution of Al Composite Powders Reinforced by Nanoand Micrometric SiC Particles During Mechanical Milling

Abstract

Aluminum powder and 5 vol.% SiC particles with an average diameter of 50 nm are milled to produce Al-SiC nanocomposite. Al matrix composite containing 5 vol.% SiC with the average particle size of 1 μm was also produced and characterized to examine the influence of nanometric and micrometric reinforcement particles on the mechanical milling process. It was shown that the presence of hard ceramic particles leads to a faster work-hardening and promotes the onset of the fracture process of Al particles. The effect of nanometric SiC on the milling stages was found to be slightly less pronounced as compared with the micrometric SiC. The analysis of XRD patterns revealed that grain refinement occurred faster in the aluminum matrix reinforced with nanometric hard particles.