Nano silica powder was firstly dispersed in aqueous solution by using silane coupling agent, and then the nano modified electrophoretic coating was prepared on phosphated steel by adding the nano silica powder to the cathoidc electrophoretic lacquer. The corrosion resistance of phosphating-electro-phoretic composite coating was determined. The microstructure observation results show that nano modified electrophoretic coating has a small protrusions on the surface, whereas the unmodified composite coating has a smooth surface. The result of water absorption shows that the modified coating has a better hydropho-bic performance that unmodified composite coating. Although two composite coatings have a higher alkali resistance, the acidic resistance of modified composite coating is greater than that of unmodified composite coating.%以获得纳米二氧化硅改性阴极电泳漆为目的,用硅烷偶联剂在水介质中分散纳米SiO2粉体,通过分散液的吸光度来评价分散效果.然后将分散后的纳米粉体添加到阴极电泳漆中得到纳米改性电泳漆.试片经磷化-电泳涂装后得到复合涂层,并对复合涂层的耐蚀性能进行评价.金相显微观测表明,纳米改性电泳漆膜表面有较均匀的小突起,而未改性复合膜层表面比较光滑.吸水性测试表明,与未改性复合漆膜相比,改性后的复合涂层漆膜疏水性能有一定提高.耐酸、碱性试验表明,改性复合膜层的耐酸性明显优于未改性复合膜层,两种复合膜层的耐碱性都较好.
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