十二烷基苯磺酸钠对镁合金表面钒酸盐转化膜的改性研究  

Research on modification of vanadate conversion coating on magnesium alloy surface with sodium dodecyl benzene sulfonate

作　　者：曹卫东[1] 郭瑞光[1] 

机构地区：[1]西安建筑科技大学西北水资源与环境生态教育部重点实验室,陕西西安710055

出　　处：《电镀与涂饰》2014年第21期915-918,共4页Electroplating & Finishing

基　　金：国家自然科学基金(20976143);教育部高等学校博士学科点专项科研基金(20096120110007)

摘　　要：采用十二烷基苯磺酸钠(SDBS)对镁合金表面偏钒酸盐转化膜进行改性。研究了SDBS含量、p H、转化时间和温度等对钒酸盐转化膜耐蚀性的影响,得到较优的成膜工艺条件为:偏钒酸铵2.2 g/L,SDBS 1.2 g/L,p H 4.4,温度30°C,时间16 min。分别采用扫描电镜、能谱仪、中性盐雾试验、电化学工作站和红外光谱仪分析了转化膜的表面形貌、成分、耐蚀性和组织结构。结果表明,改性后的转化膜为无定形结构,含Mg、O、C、F、Al、V元素和SDBS有机官能团。改性转化膜在Na Cl溶液中的腐蚀电位和腐蚀电流密度分别为-1.246 V和5.99×10-6 A/cm2,中性盐雾试验时间长达72 h,耐蚀性能远优于未改性转化膜。The vanadate conversion coating on magnesium alloy surface was modified with sodium dodecyl benzene sulfonate （SDBS）. The optimal process conditions obtained by studying the effects of SDBS content, pH, conversion time and temperature on the corrosion resistance of conversion coating are as follows： ammonium metavanadate 2.2 g/L, SDBS 1.2 g/L, pH 4.4, temperature 30℃, and time 16 min. The surface morphology, composition, corrosion resistance, and microstmcture of conversion coating were analyzed by scanning electron microscopy, energy-dispersive spectroscopy, neutral salt spray test, electrochemical workstation, and infrared spectroscopy. The results showed that the modified conversion coating is amorphous and consists of several elements including Mg, O, C, F, Al, and V, and organic functional groups of SDBS. The modified conversion coating has much better corrosion resistance than the unmodified one, with a corrosion potential of -1.246 V, a corrosion current density of 5.99 × 10^-6 A/cm^2 in NaC1 solution, and a neutral salt spray test time up to 72 h.

关 键 词：镁合金 转化膜 偏钒酸铵 十二烷基苯磺酸钠 耐蚀性 

分 类 号：TQ153.6[化学工程—电化学工业]