Influence of sodium metanitrobenzene sulphonate on structures and surface morphologies of phosphate coating on AZ91D

• Published in: Transactions of Nonferrous Metals Society of China Vol. 16; no. 3; pp. 567 - 571
• Main Author: 牛丽媛 李光玉 江中浩 孙丽萍 韩冬 连建设
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.06.2006; Key Laboratory of Automobile Materials, Ministry of Education, College of Materials Science and Engineering,Jilin University, Changchun 130025, China
• Subjects: AZ91D; magnesium alloy; phosphating process; sodium metanitrobenzene sulphonate; zinc phosphate coating; 磷酸盐处理; 磷酸锌涂层; 表面形态; 镁合金; zinc phosphate coating; magnesium alloy; phosphating process; sodium metanitrobenzene sulphonate; AZ91D; AZ91 D
• ISSN: 1003-6326
• DOI: 10.1016/S1003-6326(06)60099-X

The gray phosphate coating was formed on AZ91D magnesium alloy from the zinc phosphating bath containing sodium metanitrobenzene sulphonate in about 4 min. The structure, surface morphologies and phase compositions of the phosphate coatings were observed and analyzed by using SEM, XRD and EDS. It is shown that the phosphate coating becomes denser and has less micro holes with increasing the concentration of sodium metanitrobenzene sulphonate in the bath in the range of 2.0 to 6.0 g/L. The addition of sodium metanitrobenzene sulphonate greatly increases the micro cathode sites for the formation of the phosphate coating and decreases the porosity of the coating.