铝合金表面硅烷化膜层的表征及电化学分析

为了充分地了解双-[3-(三乙氧基)硅丙基]硫化物(BTESPT)水溶胶和膜层的形成过程及结构变化,采用傅立叶反射吸收红外光谱(FTIR-RA)和电化学阻抗谱(EIS)分析以及扫描电子显微镜(SEM)观察分析,对沉积在YL12铝合金表面的BTESPT水溶胶膜层进行了表征.结果表明,水解时间和固化工艺对膜层的组分和结构有显著影响,高温固化形成膜层的电化学阻抗比室温陈化形成膜层的阻抗更高,并且室温预陈化后的膜层在非腐蚀性水溶液中需进一步陈化才能提高膜层的致密性和均匀性.

Characterization and Electrochemical Analysis of a Silanizing Film on Aluminum Alloy

Bis-[3-triethoxysilylpropyl]-tetrasulfide (BTESPT) hydrosol was used as the raw material to prepare a film on YL12 aluminum alloy substrate using sol - gel method. The resulting BTESTP film was characterized by means of Fourier transformation infrared reflection absorption spectroscopy ( FTIRRAS ) , electrochemical impedance spectroscopy (EIS) , and scanning e-lectron microscopy (SEM) , aiming at acquiring insights into the transformation process of the hydrosol and the structure and electrochemical features of the sol - gel film. It was found that the composition and structure of the BTESPT film were significantly dependent on the time of hydrolysis and process of curing. The film cured at high temperature had higher electrochemical impedance than that aged at room temperature ( RT). Moreover, it was imperative for the film pre-aged at room temperature to be further aged in non-corrosive aqueous solution so as to improve the uniformity and compactness.