镁合金上硅酸盐/钨酸盐复合转化膜的研究  

Study of Silicate and Tungstate Composite Conversion Coatings on Magnesium Alloy

作　　者：李智[1] 戴崇良[1] 刘娅莉[1] 朱婧[1] 

机构地区：[1]湖南大学化学化工学院,湖南长沙410082

出　　处：《电镀与环保》2007年第1期16-19,共4页Electroplating & Pollution Control

摘　　要：研究了以硅酸盐和钨酸盐为主的无铬化学处理液在镁合金上所形成的转化膜。讨论了钨酸盐、KMnO4对膜层的影响。试验得出了最佳的反应pH值、温度和时间。转化膜的微观结构用扫描电镜观察,极化曲线和电化学阻抗分析则用来表征转化膜的耐蚀性,采用X射线衍射谱研究了转化膜的微观相结构,发现是以非晶态形式存在,并使用能谱进行膜的成分分析,提出了转化膜成膜机理。A conversion coating formed on magnesium alloy AM60 with a chromate-free bath mainly composed of silicate and tungstate is studied. The effects of tungstate and KMnO4 on the coating are discussed. The best time, acidity and temperature of reaction are obtained through comparison. The microstructure of the conversion film is observed with scanning electron microscopy. Polarization curves and electrochemical impedance analysis are used to indicate the corrosion resistance of the conversion coating. The microfacies structure of the conversion coating is investigated by X-ray diffraction spectrum, revealing that the film is of noncrystalline structure. The components of the conversion film are analyzed by energy spectrum. On this basis, the growth mechanism of the chemical conversion coating is put forward.

关 键 词：镁合金 无铬 硅酸盐 钨酸盐 

分 类 号：TG174[金属学及工艺—金属表面处理]