Effect of Copper/Alumina Hybrid Reinforcement on the Microstructure and Mechanical Properties of Stir Cast Aluminum Alloy AA6063

Abstract

The present study investigated the microstructural characteristics and mechanical behavior of hybrid composites with an aluminum matrix reinforced with copper and alumina. To prepare these composites, copper and alumina were mixed in varied weight ratios and added to a 10 wt % hybrid reinforced Al-Mg-Si alloy using a two-step stir casting process. The resulting composites were characterized using hardness, tensile properties, and scanning electron microscopy. The findings reveal that composites with Al-90 %/Cu-7.5 %/ Al2O3-2.5 % and Al-90 %/Cu-5 %/ Al2O3-5 % exhibited the optimum mechanical properties, including hardness and tensile properties. The microstructure of all composites showed the presence of copper particles and Al2O3 reinforcement, which were distributed nearly uniformly throughout the metal matrix despite the presence of pores. The EDS profile of a representative composite showed peaks of aluminum (Al), copper (Cu), carbon (C), magnesium (Mg), silicon (Si), oxygen (O), manganese (Mn), and traces of calcium (Ca), sulfur (S), and potassium (K). Based on these results, further investigation could be conducted on the wear and corrosion properties of the aluminum alloy when reinforced with copper and alumina.