Additive-assisted cerium-based corrosion-resistant e-coating: Corrosion resistance of metallic components such as stainless steel components of vehicles and especially aluminum-based components of aircraft is enhanced by application of an e-coat paint or primer which is enhanced by incorporation of cerium ions into the e-coat electrolytic bath. The resulting overall coating includes a cerium-based layer under a cerium-enhanced e-coat paint or primer layer. Non-Confidential Abstract of Invention: An additive for cathodic e-coat system has been developed which is based on the incorporation of a cerium salt into the deposited paint. Elemental analysis shows cerium is not only present in the paint film but also concentrates at the bulk substrate. The presence of this corrosion inhibitor can improve the overall corrosion resistance of the coating. Examination of scribed areas after corrosion testing as well as electrochemical data (EIS) shows the inhibitor is active in re-passivating exposed areas. Applications: Barrier type coatings for the aerospace and automotive industries; Coats irregularly shaped objects. Stage of Development: Laboratory scale experiments are still being conducted.
1) May replace chromate or phosphate pre-treatments; 2) Provides non-toxic corrosion inhibition of Al alloys and phosphated steel; 3) Choice of soluble Ce salt allows for more dissociation and protection; 4) Easy to incorporate into cathodic e-coat formulations.