Phase Structure, Microstructure, Corrosion, and Wear Resistance of Al0.8CrFeCoNiCu0.5 High-Entropy Alloy

Abstract

This study investigates the structure and corrosion behavior of the Al0.8CrFeCoNiCu0.5 high-entropy alloy prepared using non-consumable vacuum arc melting. XRD analysis identified BCC1 and BCC2 phases corresponding to (Fe-Cr) and Al-Ni, respectively, while the FCC phase aligned with Cu. SEM and EBSD observations confirmed an equiaxed grain structure with fishbone-like morphology at grain boundaries and modulated structures within the grains. The alloy exhibited minimal residual stress and strain. The alloy demonstrated a preferred orientation of grain growth along the <001> direction. Electrochemical testing in a 3.5% NaCl solution revealed a corrosion potential of −0.332 V and a corrosion current density of 2.61 × 10−6 A/cm2. The intergranular corrosion regions exhibited significant depletion of Al and Cu elements, with the corrosion products primarily consisting of Al and Cu. Al and Cu elements are susceptible to corrosion. The wear scar width of Al0.8CrFeCoNiCu0.5 high-entropy alloy is 1.65 mm, which is less than 45# steel, and high-entropy alloy has more excellent wear resistance. Given its unique attributes, this high-entropy alloy could find potential applications in high-end manufacturing industries such as the aerospace engineering, the defense industry, energy production, and chemical processing where high corrosion resistance and wear resilience are crucial.