Effect of Heat Treatment on Mechanical Properties of Stir-Casted Al7075-SiC Composites

Abstract

Composites made of aluminium are the preferred choice for most of the researches working on metal matrix composites. Some of the benefits obtained on using aluminium matrix composites are high strength with minimal weight, good resistance to wear and good stiffness. In addition, materials made from aluminium also have better electrical conductivity and thermal expansion coefficient. Amongst various methods available for manufacturing composites, stir casting is the best effective method. The reason behind using this method is achieving homogeneous distribution of reinforcement within the matrix, cost economy and availability. The impact of heat treatment on resulting properties of the composite samples was analysed in this study. Al7075 is used as reinforcement, and silicon carbide at 4, 6 and 8 wt% is used to produce composite specimens. Stir casting method is used for the manufacturing because of enormous benefits obtained by this process. Care has been taken to achieve uniform dispersion of reinforcements in the melt. The specimens are structured to ASTM standards to evaluate their properties. T6 heat treatment is performed. Tensile, hardness and wear tests were performed, and the microstructure of the samples was analysed. The properties of the heat-treated specimens were found to be superior for composite sample having 6% of SiC than other samples.