Corrosion Resistance of FeCrMnxAlCu High-Entropy Alloy in 3.5wt% NaCl Solution

FeCrMnxAlCu (x=0, 0.5, 1.0, 1.5, 2.0) high-entropy alloys were prepared using a vacuum arc melting furnace. The microstructure and chemical composition of the alloys were analyzed using XRD, SEM and EDS. Additionally, the corrosion resistance of the alloys in 3.5 wt%NaCl solution was evaluated through electrochemical polarization curve tests and immersion experiments. After corrosion, the alloy surfaces were analyzed using XPS equipment. The results of microstructure characterization show that the prepared high-entropy alloys exhibit typical dendritic and interdendritic structures and possess a dual-phase fcc and bcc structure. Corrosion test results indicate that the corrosion resistance of the high-entropy alloys increases initially and then decreases with the increase in Mn content. However, compared with the alloy without Mn, alloys containing Mn still exhibit better corrosion resistance. Among them, the FeCrMnAlCu high-entropy alloy demonstrates the best corrosion resistance with a more positive corrosion potential (E-corr= -0.417 V) and a smaller corrosion current density (I-corr=2.120x10(-6) A center dot cm(-2)). Furthermore, the FeCrMnxAlCu high-entropy alloys exhibit activation behavior and form discontinuous and loose corrosion product films.