Corrosion and Adhesion Properties of Cerium-Based Conversion Coatings on Magnesium Alloys

摘要

Corrosion resistance and adhesion properties of cerium-basedconversion coatings (CeCCs) on Al/Zn and Al/Mn magnesiumalloys have been investigated. CeCCs were deposited byimmersing magnesium panels in a cerium ion containing solutionfor 2 minutes. Corrosion resistance and adhesion strength ofcerium coated magnesium panels were evaluated byelectrochemical and pull tab testing methods, respectively. TheCeCCs had very good adhesion to and significantly improved thecorrosion resistance of magnesium alloys. Electrochemical testresult showed that there was a measurable difference in corrosionresistance between the different magnesium alloys. Magnesiumalloys with higher aluminum content had better corrosionresistance than alloys with lower Al content. The correlation ofcerium deposition conditions, corrosion resistance, and adhesionstrength are discussed.