纳米二氧化硅对铝合金表面环氧涂层耐蚀性能的影响

Effects of Nano SiO_2 on the Corrosion Resistance of Epoxy Resin Coatings on Aluminum Alloys

通过往环氧树脂涂层中添加纳米二氧化硅制备了二氧化硅/环氧树脂涂层,采用Machu测试和电化学阻抗谱分析了二氧化硅/环氧树脂涂层的耐蚀性能,并对电化学阻抗谱数据进行分析得到涂层的孔隙率。结果表明:未添加二氧化硅环氧树脂涂层的耐蚀性最差,添加10%二氧化硅环氧树脂涂层的耐蚀性最优;二氧化硅在环氧树脂涂层中起到阻挡屏蔽作用,但添加的二氧化硅过多时,容易发生团聚现象,导致涂层的耐蚀性下降;涂层的孔隙率越大,意味着涂层中的微孔数量越多,微孔面积越大,导致腐蚀介质的传输通道越多,涂层的耐蚀性越差。

SiO2/epoxy resin coatings were prepared by adding nano SiO2 in epoxy resin coating. The corrosion resistance of SiO2/epoxy resin coatings was studied by Machu test and electrochemical impedance spectroscopy（ EIS）. The porosity of the coatings was obtained by analyzing the EIS. The results show that the pure epoxy resin coating added with 0% SiO2 had the worst corrosion resistance,while the epoxy resin coating added with 10% SiO2 had the best corrosion resistance. The SiO2 acted as a barrier shield in epoxy resin coatings,but agglomeration occurred in the epoxy resin coating added with too much SiO2,which decreased the corrosion resistane of the coating. The larger the porosity of coating,the more the micropores and the larger the micropore areas in the coatings,resulting in more transmission channels for corrosive medium and bad corrosion resistance of SiO2/epoxy resin coatings.