Chromic acid anodization (CAA) is used in the US DoD for localized repair of aluminum and its alloy components on multiple weapon systems. Although CAA is effective at preventing corrosion, hexavalent chromium is a toxic heavy metal and known carcinogen that poses environmental and occupational safety and health risks throughout the lifecycle of the plated parts. Therefore, the use of hexavalent chromium is strictly regulated, and effective alternatives are actively sought out. Thin-Film Sulfuric Acid Anodize (TFSAA) is an environmentally friendlier alternative to CAA as well as a preferred occupational health substitute. Corroded components can be repaired using a novel Dripless Repair System (DRS) to touch up localized damaged areas on or off aircraft as well as areas that are unable to be coated via immersion. The USAF is working with ES3 to demonstrate and validate the portable brush anodize process on weapons systems. The process is achieved by controlling electrical potential and developing process parameters such as solution concentration and dwell time. The DRS can anodize aluminum substrates without the use of hexavalent chromium and with greater accuracy and repeatability than legacy brushed repair methods — and all while reducing waste generation and exposure to hazardous chemicals.
