Intelligent self-healing corrosion resistant vanadia coating for AA2024

Abstract

This paper is a continuation of our investigation into the designing of chromate-free anti-corrosion coatings for aluminum and magnesium based materials for marine, automotive and aerospace applications. In this paper, a simple vanadia based chemical conversion coating was applied for improving the corrosion resistance of high strength AA2024 alloy. The effect of vanadia solution concentrations (10, 30 and 50 g/l) on the corrosion behavior was investigated. EIS, linear polarization and cyclic voltammetry techniques were used to evaluate the electrochemical behavior in 3.5% NaCl. Vanadia coatings prepared by dissolving 10 g of vanadate salt per liter showed the best localized corrosion resistance as measured by EIS and polarization techniques. The optimum conditions to obtain corrosion protective coatings for AA2024 were determined. Surface examination of the samples was investigated using AFM, SEM-EDS and macroscopic images.