摘要
通过依次浸入水基硅烷化溶液及铈盐处理液,在铝金属表面制备了硅烷–铈盐杂化膜,并通过电化学阻抗谱(EIS)及动电位扫描极化曲线分析了杂化膜的耐蚀性能,通过盐水浸泡试验研究了杂化膜的耐久性,采用扫描电子显微镜和X射线能谱仪(SEM/EDS)表征了杂化膜的微观形貌及元素组成。结果表明,硅烷–铈盐杂化膜具有较单一硅烷膜和铈盐转化膜更好的致密度及疏水性,且杂化膜对铝的阴、阳极反应均起到了明显的抑制作用。相对于空白样,硅烷–铈盐杂化膜的腐蚀电流密度降低了约2个数量级,有效地提高了铝的耐腐蚀性能。铈盐掺杂后使膜层具有了一定的"自修复"能力,能够为金属基体提供与铬酸盐钝化膜相当的长效防腐作用。硅烷–铈盐杂化膜同时具有铈盐转化膜与硅烷膜的形貌特征,硅烷化预处理增加了铝表面的活性和粗糙度,对后续杂化膜的形成起到显著的促进作用。
A silane-cerium salt hybrid film on surface of aluminum metal was prepared by immersing the aluminum sheet in water-based silanization solution and cerium salt solution in turn, and the corrosion resistance of the hybrid films was analyzed by electrochemical impedance spectroscopy （EIS） and potentiodynamic scanning polarization curve measurement. The durability of hybrid film was tested by salt solution immersion test. The microstructure and chemical composition of the film were characterized by scanning electron microscope and energy-dispersive X-ray spectrometer （SEM/EDS）. The results indicated that the compactness and hydrophobicity of silane-cerium salt hybrid film are better than that of the single silane film and cerium conversion film. The hybrid film can remarkably inhibit the cathode and anode reaction of aluminum substrate. Compared with the blank sample, the corrosion current density of silane-cerium hybrid film coated sample is decreased by about two orders of magnitude, indicating that the corrosion resistance of aluminum is effectively improved. Cerium-doped silane film has a certain ＂self-healing＂ effect, providing a long-lasting corrosion protection comparable to chromate passivation film for metals. The silane-cerium hybrid film has both morphologic features possessed by silane film and cerium conversion film. The silanization pretreatment increases the activity and roughness of aluminum surface, promoting the subsequent formation of hybrid film.
出处
《电镀与涂饰》
CAS
CSCD
北大核心
2015年第14期821-827,共7页
Electroplating & Finishing
关键词
铝
硅烷
硝酸铈
杂化膜
耐蚀性
电化学阻抗谱
aluminum
silane
cerous nitrate
hybrid film
corrosion resistance
electrochemical impedance spectroscopy
