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

摘要

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.