Protective properties of chromate-free conversion coatings for copper-containing aluminum alloys in tropical climates

• Y.A. Kuzenkov¹, D.O. Chugunov¹, V.A. Karpov², T.T. Trang³, S.V. Bel’skii³ and N.V. Thang³

¹ A.N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, Leninsky pr. 31, 119071 Moscow, Russian Federation
² Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, 119071, Moscow, Russian Federation
³ Joint Russian–Vietnamese Tropical Research and Technology Center, Hanoi, Socialist Republic of Vietnam

Abstract: Copper-containing aluminum alloys have low corrosion resistance due to the presence of copper-rich intermetallic phases in the alloy composition. In the case of atmospheric corrosion, increased humidity and the presence of chlorides can significantly accelerate the corrosion processes for these alloys. In this work, V95T3 and 1105 copper-containing aluminum alloys and IFKhANAL-3 chromate-free inhibited conversion coatings (CС) for their protection were studied for 2 years in tropical climate. Full-scale corrosion tests were carried out at the corrosion test station of the Joint Russian–Vietnamese Tropical Research and Technology Center in the suburbs of Hanoi, Hoa Lac station, Vietnam. It was shown that in these climatic conditions, IFKhANAL-3 chromate-free CС can protect 1105 alloy for 12 months, and V95T3 alloy for 24 months. To increase protective properties of the alloys, additional treatment of these coatings was carried out with acrylate varnish and a layer of low molecular polytetrafluoroethylene (PTFE). This makes it possible to completely protect the 1105 and V95T3 aluminum alloys for 2 years in tropical climates.

Keywords: aluminum alloys, conversion coating, pitting corrosion, corrosion inhibitors, atmospheric corrosion testing, tropical climate, field tests

Int. J. Corros. Scale Inhib., 2024, 13, no. 3, 1664-1672
doi: 10.17675/2305-6894-2024-13-3-17

Download PDF (Total downloads: 56)

Back to this issue content: 2024, Vol. 13, Issue 3 (pp. 1355-1890)