Effects of Ultrasonic Shot Peening on the Corrosion Resistance and Antibacterial Properties of Al 0.3 Cu 0.5 CoCrFeNi 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 Al_0.3Cu_0.5CoCrFeNi 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. [ABSTRACT FROM AUTHOR]