Effects of current density on the corrosion behaviour of anodized aluminum alloy in FeCl3 solution

In the present study,2024 aluminum alloy specimen was anodized in acetic acid and oxalic acid electrolytes.Effects of the current density on the microstructure and corrosion resistance of anodic oxide film have been investigated.The steady voltage increases from 11 V to 71 V with the current density increase from 0.5 A /dm² to 2.5 A /dm².The SEM reveals that there are pits,cavities and irregular pores in the anodic film,and their size and morphologies change with the current density.The corrosion resistance of the film was evaluated by potentiodynamic polarization and electrochemical impedance in 0.1 mol /L FeCl₃ solution at room temperature.The results show that corrosion resistance of the anodic oxide film changes with the current density,and the anodic film formed at the current density of 1.0 A /dm² has the best corrosion resistance.These observations indicate that anodic film formed at J = 1.0 A /dm² can serve as a support material for the Cu micrometallic patterns.