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

摘要

Corrosion resistance and adhesion properties of cerium-based conversion coatings (CeCCs) on Al/Zn and Al/Mn magnesium alloys have been investigated. CeCCs were deposited by immersing magnesium panels in a cerium ion containing solution for 2 minutes. Corrosion resistance and adhesion strength of cerium coated magnesium panels were evaluated by electrochemical and pull tab testing methods, respectively. The CeCCs had very good adhesion to and significantly improved the corrosion resistance of magnesium alloys. Electrochemical test result showed that there was a measurable difference in corrosion resistance between the different magnesium alloys. Magnesiumalloys with higher aluminum content had better corrosion resistance than alloys with lower Al content. The correlation of cerium deposition conditions, corrosion resistance, and adhesion strength are discussed.