Processing of squeeze cast Al6061–30vol% SiC composites and their characterization

6061 aluminum matrix composites containing 30vol% SiC with mean mass particle size of 16 and 22 μm as the reinforcing phase were synthesized by squeeze casting route. The process consisted of fabricating of SiC preform followed by squeeze casting of 6061 aluminum alloy. The SiC preform was made by blending SiC particles with silica as a coal and sintering. The microstructural features, aging behavior, mechanical properties and wear characteristics of the composites were investigated. The results indicated that a homogenous distribution of SiC particles in the aluminum matrix, which is almost free of pores, can be obtained by squeeze casting method. Higher strength and lower wear rates were observed in the composite materials than the unreinforced aluminum alloy part. However, a marked decrease in ductility of the composites arising from adding of SiC particles was obtained. The aging behavior of the aluminum alloy was found to be influenced by the reinforced materials, i.e. the time to obtain the peak hardness in T6 treatment was lower for the composites than the unreinforced material. The fracture surfaces of the unreinforced and composite samples exhibited dimple surfaces. The wear resistance of the aluminum alloy was improved by reinforcing with SiC particles and it is comparable with unalloyed pearlitic cast iron. This article presents the effect of SiC particles on the aging behavior, mechanical properties and wear resistance of 6061 aluminum alloy made by squeeze casting method.