Protective properties of PEO coatings modified by corrosion inhibitors on aluminum alloys

• S.V. Oleynik¹, V.S. Rudnev², Yu.A. Kuzenkov¹, T.P. Jarovaja², L.F. Trubetskaja¹ and P.M. Nedozorov²

¹ A.N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, Leninsky pr. 31, Moscow, 119071 Russian Federation
² Institute of Chemistry, Far-Eastern Branch of the Russian Academy of Sciences, pr. 100-letiya Vladivostoka 159, Vladivostok, 690022 Russian Federation

Abstract: The protective properties of PEO coatings on aluminum alloys belonging to various alloying systems (Al–Mg, Al–Mg–Cu–Zn, Al–Mn) in chloride media were studied. Coatings with varoius thickness (8–40 µm) was obtained by oxidation of flat samples in borate, silicate and borate–phosphate–tungstate electrolytes. It was shown that coatings on aluminum alloys doped with manganese or magnesium (3003 and 5083) have a slightly higher resistance to pitting corrosion in chloride environments compared to copper-based alloys 2024 and 7075. According to polarization studies and corrosion tests, filling of the coatings studied with IFKHAN-25 and IFKHAN-39 corrosion inhibitors increases by more than an order the time of protection of the specimens made of various types of aluminum alloys. It was observed that chemical sorption of corrosion inhibitors is the determining factor in increasing the protective ability of PEO coatings in the entire range of thicknesses. Hydrophobization of coatings filled with corrosion inhibitors increases their corrosion resistance in chloride environments to an even greater extent.

Keywords: aluminum alloys, PEO coating, corrosion inhibitors, filling of coatings.

Int. J. Corros. Scale Inhib., 2017, 6, no. 2, 91–111 PDF (2 198 K)
doi: 10.17675/2305-6894-2017-6-2-1

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