Microstructure, mechanical, and wear characteristics of heat-treated aerospace-grade aluminium composite reinforced with HEA particles

This research paper investigates the mechanical, microstructural, and wear characteristics of Al7075 composite reinforced with high entropy alloy particles. Stir casting, equipped with an ultrasonic probe, was used for the fabrication of the composite. Microstructural analysis including optical microscopy, scanning electron microscopy with energy dispersive spectroscopy, and X-ray diffraction, was conducted assess the microstructure and dispersion of reinforced particles in the composite and alloy. Results indicated that hardness and tensile strength increased with higher weight percentages of reinforcement, while percentage elongation decreased. However, properties decreased with further reinforcement beyond 6 wt% in the composite. Mechanical testing revealed that heat treated composites with 6.0 wt% HEAp have maximum UTS and hardness of 287.6 MPa and 117.2 HRB, respectively. Fracture morphology analysis further provides insights into the interactions between the HEAp and the aluminium matrix, shedding light on crack initiation, propagation, and the role of HEAp in influencing the fracture mechanisms. A comprehensive examination of the worn surface was conducted using SEM and an optical profilo-meter.