Study on cavitation erosion-corrosion behavior of CoCrFeNiMoCu high entropy alloy in 3.5 wt% NaCl solution.

The challenge of cavitation erosion (CE) in flow-handling components of marine engineering has promoted the development of advanced materials due to safety incidents and economic costs. High entropy alloys (HEAs), known for high hardness and corrosion resistance, emerge as promising candidates. This paper delved into the CE characteristics of CoCrFeNiMoCu HEA when subjected to the 3.5 wt% NaCl solution, elucidating the synergistic effect of CE-corrosion. The quantitative analysis revealed that CE-corrosion synergy contributed 48.02% to total CE mass loss, primarily attributed to corrosion-induced CE damage. Meanwhile, electrochemical noise (EN) was utilized to reveal the corrosion behavior of CoCrFeNiMoCu HEA in 3.5 wt% NaCl solution combined with the morphologies observation and surface roughness. Extended CE time compromised the corrosion resistance of CoCrFeNiMoCu HEA and diminished the impact of selective phase corrosion on the surface. Eventually, the CE damage mechanism of CoCrFeNiMoCu HEA was revealed based on pertinent experimental findings. The results showed that with increased CE time, the CoCrFeNiMoCu HEA transitioned from predominantly extensive exfoliation of the initial FCC phase to further damage of the intermetallic σ and μ phases.