CERIUM, COBALT AND MOLYBDATE CATION STORAGE STATES, RELEASE AND CORROSION INHIBITION WHEN DELIVERED FROM OXIDES ON ALUMINUM - TRANSITION METAL - RARE EARTH METAL ALLOYS

摘要

Aluminum and aluminum alloys can be protected against corrosion by various means (e.g., anodizing and sealing, chromate conversion coating, metallic cladding with Alclad, chromate conversion primers, corrosion protection compounds and solution phase inhibitors). The desire to deploy environmentally compliant multifunctional coatings has created the need for new concepts that can protect Al-base precipitation age-hardened alloys. A new generation of aluminum alloys with certain transitions metals and lanthanides in an amorphous state provides an opportunity to create an environmentally compliant metal coating capable of performing multiple functions. Such metallic coatings have excellent intrinsic the resistance to localized corrosion that makes them good corrosion barriers, while at the same time exhibiting favorable galvanic couple characteristics relative to AA2024-T3. They also have the potential to provide a means for active corrosion protection at coating defects that expose underlying structural alloys (Fig. 1). The desired attributes of any new inhibitors (whether stored in a metal or polymer coating) are high capacity in the coating, high solubility in the aqueous phase over the coating when released, and high inhibitor efficiency. If such novel alloys are successful, the opportunity exists to provide new multi-functional metallic cladding alloys that exhibit a broad range of corrosion functions.