Corrosion Behavior of CrFeCoNiVx (x = 0.5 and 1) High-Entropy Alloys in 1M Sulfuric Acid and 1M Hydrochloric Acid Solutions

Abstract

CrFeCoNiVx high-entropy alloys were prepared by arc-melting, and the microstructures and corrosion properties of these alloys were studied. The CrFeCoNiV0.5 alloy had a granular structure; the matrix was a face-centered cubic (FCC) structure, and the second phase was a σ phase with a tetragonal structure. The CrFeCoNiV alloy had a dendritic structure; the dendrites in this alloy showed an FCC phase, and the interdendrities had a eutectic structure of FCC and σ phases. Therefore, CrFeCoNiV was much harder than the CrFeCoNiV0.5 alloy due to the dendritic structures. The potentiodynamic polarization test and electrochemical impedance spectroscopy were used to evaluate the corrosion behavior of the CrFeCoNiVx high-entropy alloys in deaerated 1M sulfuric acid and 1M hydrochloric acid solutions. The results indicated that the CrFeCoNiV0.5 alloy had a better corrosion resistance because of the granular structure.

Corrosion Behavior of CrFeCoNiV0.5 and CrFeCoNiV Alloys in 0.5 M and 1 M Sodium Chloride Solutions

“…The microstructures and hardness of as-cast CrFeCoNiV 0.5 and CrFeCoNiV alloys were studied in our previous study [18], and the corrosion resistance of CrFeCoNiV 0.5 and CrFeCoNiV alloys in 1 M H 2 SO 4 and 1 M HCl solutions was included. The SEM micrographs of CrFeCoNiV 0.5 and CrFeCoNiV alloys are shown in Figure 1 [18]. The CrFeCoNiV 0.5 alloy showed a granular structure with a few σ-phased particles in the FCC matrix.…”