Primerless Finishing Systems for the Corrosion Protection of Aluminum

摘要

A trend to develop primerless systems for military equipment has begun in which a topcoat can be applied directly to surface treated aluminum. Two approaches to obtain a primerless system are currently available and were investigated. In the first approach, a standard sulfuric acid anodized surface was sealed with a polyurethane colloidal suspension. The resulting pretreatment can be directly topcoated. The second approach involved the application of a primerless or self-priming topcoat applied directly to a surface pretreatment. Adhesion, electrochemical impedance spectroscopy, flexibility and corrosion resistance tests were performed on several aluminum substrates to determine the physical properties of the coating-pretreatment systems. The results of this analysis indicate that these primerless systems show promise and should be considered for specific finishing system applications. Keywords: Primerless coating systems; Organic coatings; Corrosion protection; Inorganic pretreatments; Coatings; Primers; Finishes. (kt)