Chemical conversion coating on AZ31B magnesium alloy and its corrosion tendency  

作　　者：Hualan JIN Xiangjie YANG Ming WANG 

机构地区：[1]School of Materials Science and Engineering, Nanchang University, Nanchang 330031, China [2]School of Mechanical and Electronic Engineering, Nanchang University, Nanchang 330031, China

出　　处：《Acta Metallurgica Sinica(English Letters)》2009年第1期65-70,共6页金属学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(No.50474007);Science and Technology Project of Jiangxi Provincial Departmentof Education (No.[2006]1)

摘　　要：The morphology change of the magnesium matrix after pre-treatment and the morphology as well as the phase composition of chemical conversion coating formed by phosphate were studied using scanning electron microscope and X-ray diffraction. The corrosion resistance of the coating was studied by salt spray and damp test, and the corrosion tendency during salt immersion test was analyzed. The results show that the phase composition before and after pre-treatment is almost changeless, and the deep microflaw appears between a andβ phases during acidic pickling. The phosphate conversion coating is mainly composed of Mg, MgO, and some amorphous phase, and it can provide a good protection for the AZ31B alloy. Results from corrosive morphology indicate that the growth and the corrosion resistance of the phosphate conversion coating are related to the forming process of the AZ31B matrix.The morphology change of the magnesium matrix after pre-treatment and the morphology as well as the phase composition of chemical conversion coating formed by phosphate were studied using scanning electron microscope and X-ray diffraction. The corrosion resistance of the coating was studied by salt spray and damp test, and the corrosion tendency during salt immersion test was analyzed. The results show that the phase composition before and after pre-treatment is almost changeless, and the deep microflaw appears between a andβ phases during acidic pickling. The phosphate conversion coating is mainly composed of Mg, MgO, and some amorphous phase, and it can provide a good protection for the AZ31B alloy. Results from corrosive morphology indicate that the growth and the corrosion resistance of the phosphate conversion coating are related to the forming process of the AZ31B matrix.

关 键 词：Magnesium alloy PHOSPHATE Chemical conversion coating Corrosion resistance 

分 类 号：TQ126.35[化学工程—无机化工] TG606[金属学及工艺—金属切削加工及机床]