Organic-magnesium complex conversion coating on
AZ91D magnesium alloy
AZ91D magnesium alloy
(1. Key Laboratory of Automobile Materials, Ministry of Education, Jilin University, Changchun 130025, China;
2. College of Materials Science and Engineering, Jilin University, Changchun 130025, China)
2. College of Materials Science and Engineering, Jilin University, Changchun 130025, China)
Abstract: An organic-magnesium complex conversion (OMCC) coating on AZ91D magnesium alloy was obtained by treating in a solution containing organic compounds. SEM, FESEM and XPS were used to examine the surface morphology, thickness and structure of the conversion coatings. The results show that the continuous and uniform conversion coating is deposited on AZ91D alloy and the main component of the coatings is organic compound containing benzene ring, which forms a chemical bond with magnesium. The polarization measurement and salt spray test show that the corrosion resistance of the conversion coating is much higher than that of traditional chromate conversion coating.
Key words: chromium-free conversion coating; organic compound; corrosion; XPS; AZ91D magnesium alloy