Chemical conversion coatings for corrosion protection of copper and other alloys in contaminated water

摘要

A non-chromate conversion coating for copper or other alloys. The conversion coating is composed of hydrotalcite-like compound (HTlcs). The conversion coating adheres well with the alloys, and provides excellent corrosion protection. In addition, corrosion inhibitive species were incorporated into the coating. The coating with inhibitors incorporated showed damage-responsive properties. The corrosion protection property of the conversion coating was further enhanced through applying a surface sealer. The coating has applicability in industrial heat exchangers that use reclaimed water.

主权项

1. A non-chromate conversion coating formulation for copper and copper alloy substrates comprising:
a) water soluble salts to provide aluminum ions, said water soluble salts forming an acidic coating solution; b) oxidative water soluble salts to accelerate the anodic dissolution of copper substrate and to provide manganese ions; c) water soluble salts in the form of carbonates to provide anions; d) upon application to the substrate, forming a conversion coating being electrochemically active and electrically conductive and having a hydrotalcite-like structure.