Effects of Ultrasonic Shot Peening on the Corrosion Resistance and Antibacterial Properties of Al0.3Cu0.5CoCrFeNi High-Entropy Alloys

Cu-bearing high-entropy alloys (HEAs) have been proposed for use as structural materials in the marine environment due to their superior mechanical and antimicrobial properties. However, the Al, Cu-enriched precipitations in HEAs damage their corrosion resistance. In this study, we used ultrasonic shot peening (USSP) technology to solve this problem. USSP caused severe plastic deformation of the Al0.3Cu0.5CoCrFeNi HEA surface and dispersed the long-strip Al, Cu-enriched phases into scattered dots, which reduced the galvanic corrosion of the HEA and enhanced passive film formation. The Al, Cu-enriched scattered precipitations also increased the number of Cu2+ ion dissolution sites, leading to the improvement of the alloy's antibacterial properties.