Investigation of microstructure and mechanical properties of Al ₂O ₃ and granite-powder-reinforced Al7075 hybrid composite

Abstract

In this study, the effect of adding granite powder and alumina to Al7075 for strength enhancement is discussed. Al7075-based composites were prepared by applying a stir-casting method. The microstructural analysis of the samples demonstrated that with an increase in the reinforcement percentage the grain size reduced. With the grain refinement, the hardness showed an increasing trend for 2 % and 4 % of Al ₂O ₃ for a constant percentage of granite powder (2 %) and then showed a decreasing trend. For 4 % of Al ₂O ₃ and 2 % of the granite powder, the tensile strength was increased by 33.6 % (183 MPa) and the hardness by 34.9 % (74.2 BHN). However, the corrosion resistance was decreased because of the presence of Fe ₂O ₃ in the granite powder.