Several fluorescent materials have been identified as possible corrosion sensing coatings. These are either redox or metal ion complex materials. The redox materials are nontluorescent in the reduced state and become fluorescent upon oxidation. Incorporated into paint coatings, they provide an early warning of corrosive condkions at the metal or alloy surface, The metal ion complex materials only fluoresce when the organic compound complexes with metrd ions such as those generated in corrosion reactions. Fluorescent materials have been incorporated into paint coatings and on metal surfaces for the detection of corrosion. Oxine reacts with aluminum oxide on corroded aluminum to give a fluorescence that can be photographed in UV light. Several other materirds were found to have good fluorescence but cannot be reversibly oxidized or reduced at the present time. More work will be done with these compounds as well as with Schiff bases to develop new fluorescent chemical sensing materials for smart coating on alloy surfaces.
Keywords: Aluminum alloys, coatings, corrosion detection, fluorescence, surfaces, UV light.