Cr-FREE no-rinse conversion coatings electrochemical characterization on AA8079

The increasing the corrosion resistance of aluminum alloys using chromium-free surface treatments, especially for materials in contact with food, has become a urgent need. In order to reduce the environmental impact and save the available natural resources, surface treatments so called "no-rinse" are being developed. This paper presents the results obtained using some commercial surface conversion treatments, evaluating the corrosion resistance exhibited by bare and coated specimens. The results have shown that use of product containing Ti and Zr salts determines an increase in the corrosion resistance of the protective system if compared to a classical chromate based system. In addition, the former also reduces water consumption as the process is of the no-rinse type.