Fabrication of High Entropy Alloy Particles Reinforced Aluminum Matrix Composites via Ultrasonic Vibration: A Comprehensive Study on Microstructure, Mechanical Performance, and Tribological Characteristics

High entropy alloy particles reinforced aluminum matrix composites (HEAps/AMCs) often face challenges, such as porosity, uneven particle distribution, and subpar mechanical properties, during manufacturing. To tackle this issue, a casting method combining vortex and ultrasonic techniques is utilized. Extensive analyzes are carried out to investigate the microstructure, hardness, tensile properties, and tribological performance of HEAps/AMCs. The microstructure reveals dispersed irregular gray HEAps containing Cr/Fe‐rich face centered cubic phases and Ni/Al‐rich body centered cubic phases. These HEAps, together with primary crystal fragments, act as potential nucleation sites and refine the grain structure significantly. AMCs with 1.5 wt% HEAps produced using this method exhibit improved mechanical properties, achieving a peak hardness of 120.5 HV, a superior yield strength (YS) of 120.6 MPa, and an optimal ultimate tensile strength of 217.4 MPa. Furthermore, the inclusion of HEAps effectively impede plastic deformation at the contact surface, enhancing the wear resistance of the composites. Compared to conventional AA2219, the porosity of 1.5 wt% AMCs is reduced by 60.8% due to the ultrasonic cavitation effect. The article thoroughly calculates and analyzes the collapse pressure of ultrasonic cavitation bubbles and their correlation with vibration parameters. The mechanism is elucidated through which ultrasonic vibration affects HEAps and microstructures.