AZ91D镁合金无铬化学转化膜的性能  

Properties of chromium-free conversion coating on AZ91D magnesium alloy

作　　者：王向荣 WANG Xiangrong(No.789 Suide Road,Putuo District,Shanghai 200331,China)

机构地区：[1]上海市普陀区绥德路789号,上海200331

出　　处：《电镀与涂饰》2020年第23期1643-1647,共5页Electroplating & Finishing

摘　　要：采用由钛盐、无机酸和有机酸组成的溶液,在AZ91D镁合金表面制备了无铬化学转化膜。用附带能谱仪的扫描电子显微镜和X射线光电子能谱仪研究了转化膜的形貌和成分,通过极化曲线和盐雾试验评定转化膜的耐蚀性,采用划格试验检测转化膜的结合力,考察了不同pH的化学转化溶液在0℃和40℃条件下的稳定性。结果表明,所得到的灰白色化学转化膜主要成分为铝、镁和钛,其耐蚀性和结合力良好,最佳的pH范围是5.5~6.5。A chromium-free chemical conversion coating was prepared on the surface of AZ91D magnesium alloy in a solution composed of titanium salt,inorganic acid,and organic acid.The morphology and composition of the conversion coating were studied by scanning electron microscope(SEM)with energy-dispersive spectrometer(EDS)and X-ray photoelectron microscope.The corrosion resistance of the conversion coating was evaluated by polarization curve measurement and salt spray tests.The adhesion strength of the conversion coating was examined by cross-cut test.The stability of the chemical conversion solution with different pHs at 0℃ and 40℃ was investigated.The results showed that the main elements of the gray-white chemical conversion coating are Al,Mg,and Ti.The corrosion resistance and adhesion strength of the coating are good.The optimal pH range of the chemical conversion solution is 5.5 to 6.5.

关 键 词：铸造镁合金 无铬化学转化膜 耐蚀性 结合力 

分 类 号：TG178[金属学及工艺—金属表面处理]