Ionic liquid route for the corrosion inhibition of Al alloys: the effect of butylammonium nitrate on the corrosion of AA2024-T6

•The addition of ammonium nitrate-based ionic liquids inhibited the anodic kinetics of an Al-Cu-Mg Al alloy, revealed by the presence of a large passivation plateau.•The alkyl chain length slightly reduced the cathodic reaction, and the results suggested that the ammonium cation acted as a barrier to chloride ions.•Selective dissolution of Cu-rich particles occurred when the ionic liquid was added to the NaCl solution.