电泳涂装前铝合金阳极氧化及无镍钝化工艺研究  

Research on Anodizing and Nickel Free Passivation Process of Aluminum Alloy before Electrophoretic Coating

作　　者：陈明 CHEN Ming(Technical Center,Dongfeng Commercial Vehicle Co.,Ltd.,Wuhan 430056,China)

机构地区：[1]东风商用车技术中心,武汉430056

出　　处：《涂料工业》2025年第5期60-65,71,共7页Paint & Coatings Industry

摘　　要：【目的】开发绿色环保、反应温和的铝合金电泳涂装前表面处理工艺。【方法】采用有机酸替换传统阳极氧化工艺中的强酸,采用含钼酸盐、稀土盐、硅烷偶联剂的无镍钝化剂进行后续钝化工艺,得到阳极氧化+无镍钝化工艺。考察阳极氧化工艺和无镍钝化工艺中部分参数对所得转化膜的影响,采用带能谱仪附件的扫描电子显微镜(SEM-EDS)表征阳极氧化+无镍钝化后样品表面微观形貌和元素分布,并测试磷化、阳极氧化、阳极氧化+无镍钝化这3种表面处理后电泳漆膜性能。【结果】通电40 min,电压<12 V,温度<46℃,采用改良的阳极氧化工艺可获得厚度20μm以内的氧化膜;采用含稀土盐(1.35 g/L)的无镍钝化剂,于80~85℃处理可获得均匀、墨黑色的钝化膜;阳极氧化、阳极氧化+无镍钝化处理后电泳漆膜的物理性能和防腐性能优于磷化处理后电泳漆膜。【结论】研究所采用的阳极氧化液、无镍钝化剂所用原料易得、成本低,阳极氧化膜、无镍钝化膜的制备路线简单、环保,防腐性能较好。[Objective]To develop a high-performance,environmentally friendly,and mild reaction surface treatment process for aluminum alloy before electrophoretic coating,[Methods]Organic acids were used to replace strong acids in traditional anodizing processes,and nickel free passivators with molybdate,earth cerium salts,and silane coupling agents were used for subsequent passivation processes,resulting in an anodizing+nickel free passivation process.The influence of some parameters in anodizing process and nickel free passivation process on the obtained conversion film was investigated,a scanning electron microscope(SEM-EDS)with an energy dispersive spectrometer was used to characterize the surface microstructure and element distribution of the sample after anodizing+nickel free passivation,and tested the electrophoretic paint film performance after three surface treatments:phosphating,anodizing,anodizing+nickel free passivation.[Results]When energized for 40 min with a voltage of less than 12 V and a temperature below 46℃,an oxide film with a thickness less than 20 micrometers could be obtained using a modified anodic oxidation process.A uniform,jetblack passivation film could be achieved by treating the surface with a nickel-free passivant containing 1.35 g/L of earth cerium salts at a temperature range of 80 to 85℃.The physical properties and corrosion resistance of the electrophoretic paint film after anodizing and anodizing+nickel free passivation treatment were better than those after phosphating treatment.In this study,the raw materials used for anodizing solution and nickel free passivating agent were easily available and low-cost.[Conclusion]The preparation route of anodizing film and nickel free passivating film was simple,environmentally friendly,and indicated good corrosion resistance.

关 键 词：铝合金 阳极氧化 无镍钝化 磷化 阴极电泳 防腐性 

分 类 号：TQ639.1[化学工程—精细化工]