Perfluoropolyether-Based Micellar Aggregates Coatings for Corrosion Resistance Enhancement of Copper-Based Alloys

In this paper, a perfluoropolyether (PFPE) micellar solution was effectively deposited on metallic substrates using a dip-coating process to enhance brass and nickel aluminum bronze (NAB) corrosion resistance. Particular attention was paid to the aesthetic results as well. Enabling the metallic substrates hydrophobic to facilitate water and moisture removal was the key concept of this work. The corrosion resistance of the as-received and coated metals was investigated via a salt spray chamber test. The study focused on the characterization of the polymeric coating via dynamic light scattering and wettability tests, while the substrates were assessed with traditional metallographic techniques. The preparation of the polymeric solution was important in determining the final corrosion resistance of the two substrates. Noteworthy was the effectiveness of the PFPE-based coating when it was applied to the brass rather than the NAB. Moreover, the polymer concentration of the dip-coating polymeric emulsion was the most significant factor to obtaining adequate protection: higher polymer concentrations resulted in a decrease in corrosion resistance.