Corrosion behavior of VCrFeCoNi medium-entropy alloy in chloride solution

The present work investigates the corrosion properties and passivation layer of VCrFeCoNi medium-entropy alloy (V-MEA). The V-MEA exhibits the corrosion current density of ∼0.101 μA and corrosion potential of ∼ -0.336 V with a broad passivation region of ∼0.763 V from the potentiodynamic polarization measurement. The V-MEA shows the multilayer passivation with vanadium oxides-rich outer layer and chromium oxide-rich inner layer. The outer layer as a cation-selective layer defeats Cl− ions and the inner layer as an anion-selective species captures the Cl− ions. Resultantly, fewer Cl− ions can go through the passivation layer, leading to the broad passivation region of V-MEA.