Exploring the synergistic effects of Cu and Al₂O₃ reinforcements on nanoindentation and wear properties of aluminum based composite

The study investigates the influence of hybrid reinforcements comprising aluminum oxide (Al₂O₃) and copper (Cu) on the microstructure, nanomechanical, and wear properties of aluminum-based composites. Six different compositions were prepared, including aluminum 6063 and composites with varying ratios of Al₂O₃ and Cu. Microstructural analysis via scanning electron microscopy (SEM) revealed a transition from a relatively homogeneous distribution in Al₂O₃-reinforced composites to a network-like structure with increasing Cu content due to phase segregation. Nanoindentation tests showed that composites with higher Al₂O₃ content exhibited superior hardness and elastic modulus, with sample S2 (75 wt% Al₂O₃ and 25 wt% Cu) demonstrating the highest nanohardness, stiffness and yield pressure. This composite also showed the lowest penetration depth and the highest load-carrying capacity, indicating enhanced resistance to plastic deformation. Wear tests revealed that composites with higher Al₂O₃ content exhibited lower wear rates, while increased Cu content reduced the coefficient of friction, enhancing tribological performance. The findings underscore the significance of optimizing Al₂O₃ and Cu ratios to achieve balanced mechanical properties and wear resistance in aluminum-based composites.