Effect of SiC Particles on Microstructure and Wear Behavior of AA6061-T6 Aluminum Alloy Surface Composite Fabricated by Friction Stir Processing

Abstract

This research studies the effect of SiC particles on the microstructure and wear behavior of AA6061-T6 aluminum alloy surface composite. Friction stir processing (FSP) was used to incorporate micro-sized SiC particles into AA6061-T6 aluminum alloy to form a particulate composite surface layer. Samples were subjected to two passes of FSP with and without SiC powder at the best rotational speed of 1250 rpm, travel speed of 32 mm/min and two passes in the same direction. Microstructural observations were conducted via optical and scanning electron microscopy (SEM) of samples subject to FSP. Mechanical properties, including microhardness and wear resistance, were evaluated. The results manifested that at two passes, the FSP caused a more uniformity in the distribution of SiC particles. The addition of SiC particles to AA6061-T6 improved the hardness (improvement 62.6%) and wear resistance as compared to FSPed sample without SiC particles. The wear behavior was of a mild type or an oxidative type at low loads (5 N), which became severe or metallic wear at higher loads (20 N) for sliding time 20 min.