Effect of sulfuric acid concentration on corrosion behavior of Al0.1CoCrFeNi high-entropy alloy

The influence of H2SO4 solution concentration on the corrosion behavior of as-cast Al0.1CoCrFeNi high-entropy alloys (HEAs) is investigated. The potentiodynamic polarization curves of the Al0.1CoCrFeNi HEA exhibit excellent corrosion resistance and a wide passive region (Delta E > 1150 mV) in acid solutions. The samples show a spontaneous passivation behavior in low-concentration (0.1, 0.2 and 0.3 M) and two anodic active-passive peaks in high-concentration (0.5 and 1.0 M) H2SO4 solutions. The morphology investigation by scanning electron microscopy suggests that selective corrosion is initiated from the inter-dendrite regions. The X-ray photoelectron spectroscopy results demonstrate that the observed passive behavior variation is associated with chemical composition change of the passive films.

Automated summary

The influence of H2SO4 solution concentration on the corrosion behavior of as-cast Al0.1CoCrFeNi high-entropy alloys (HEAs) was investigated, showing different corrosion patterns in low and high concentrations of the solution. The variations in passive behavior were associated with changes in the chemical composition of the passive films, as observed in X-ray photoelectron spectroscopy results.