Effect of aluminium on the passivation of zinc-aluminium alloys in artificial seawater at 80 °C

► Pure Zn and Zn-Al alloys passivate and depassivate in artificial seawater. ► Al retards passivation of Zn-Al alloys. ► Passive film composes of the inner film and the outer charge transfer layers. ► Al increases current density but decreases corrosion resistance of passive films. ► Al increases the electrical conductivity and the capacitance of the films.