Development of Self-Healing Coatings for Corrosion Protection of Repaired Aluminum Components Following Dimensional Restoration

ABSTRACT: Chrome-based coating systems are being phased out of most applications due to the toxicity of chromium compounds. Emerging coating technologies designed to replace chrome systems exhibit a glaring technical shortcoming, which is that hey fail to replicate the self-healing functionality that stems from the reduction of Cr [VI] present in chrome-based systems to a Cr [III] oxide layer, which passivates the surface of the substrate when damage occurs. Building on recent breakthrough technologies in self-healing polymers, a functional additive is proposed as a means for incorporating self-healing functionality into primers for aluminum. When a coating containing such an additive incorporated is damaged, reactant material from the self-healing additive will be released into the site of damage where it will polymerize and restore the coating"s protective function. By combining this self-healing functionality with chrome-free pretreatment and aerospace primers and top coats that combine to meet appropriate military coating system specifications, a systems that approaches the performance levels of chrome-based systems can be attained. BENEFIT: The coating systems that result from the additives developed in this proposal will exhibit extended lifetimes and maintenance cycles that will in turn result in extended lifetimes of the assets they protect. This will result in significant cost savings from the maintenance of the coatings and the assets over their lifetime as well as limit lost productivity due to unavailability of assets during maintenance.