The influence of additional salts on corrosion inhibition by cerium(III) acetate in the protection of AA7075-T6 in chloride solution

The synergistic or adverse effects of the addition of NaOAc, NaNO3 and Na2SO4 on the performance of cerium (III) acetate as inhibitor of corrosion of aluminium alloy 7075-T6 in 0.1 M NaCl were investigated. The corrosion properties were evaluated using electrochemical polarisation and impedance methods. The composition and morphology of scribed samples during a 1-month immersion test were characterised using morphological and chemical analyses. The influence of additional salts on cerium precipitation was confirmed by acid-base titration. The most efficient long-lasting corrosion inhibition was achieved by synergism between Ce(OAc)(3) and Na2SO4 and ascribed to low solubility of the product formed.