F.J. García-García, T.Y. Chiu, P. Skeldon, G. E. Thompson
Surface and Interface Analysis, 47 (2015) 30-36
doi: 10.1002/sia.5640

Cathodic polarization of aluminium and Al–0.18 wt.% Mg and Al–0.08 wt.% Ti alloys in 0.24 mol dm⁻³ nitric acid solution at 38 °C has been employed to assist understanding of the roles of alloying elements in electrograining. The findings indicate that additions of magnesium and titanium to aluminium accelerate the corrosion of the substrate under the alkalization caused by the cathodic reactions. The accelerated dissolution and the consequent formation of hydrated alumina result in a decreased net cathodic current density in potentiostatic and potentiodynamic polarization conditions relative to the behaviour of aluminium.