Self-healing non-chromate coatings for aluminum and aluminum alloys

摘要

Disclosed are processes and compositions of solutions for chromate-replacement coatings for aluminum and aluminum alloys. A preferred method includes forming a boehmite coating layer that includes Al (III) ions on an aluminum surface, and applying an ionic conversion coating solution to the coating layer. The ionic conversion coating solution comprises hexavalent and trivalent ions. The trivalent ions are selected from the group consisting of Ce, Ga, Mn, Sc, Ti, Te and V. The hexavalent ions are selected from the group consisting of Mn, Mo, Se and W. It is contended that the resulting coatings provide corrosion resistance and self-healing effect in any defects present in the coatings.