铝管表面硅烷稀土复合膜的制备及性能研究

在60℃时采用浸渍法制备硅烷稀土复合膜,通过先在试样表面自组装一层γ-氨丙基三乙氧基(γ-APS)硅烷薄膜,再在膜上沉积稀土铈转化膜制得硅烷稀土复合膜。采用电化学、失重和盐雾实验对铝管表面硅烷稀土复合膜的耐蚀性进行考察。线性电位扫描、Tafel曲线和交流阻抗(EIS)的结果均表明其耐蚀性与空白样相比,极化电阻和自腐蚀电流均提高了两个数量级,阻抗阻值提高了2倍;盐雾实验结果也表明其抗蚀能力提高了3倍;SEM显示其复合膜层均匀致密,EDS检测分析表明复合膜主要由N,O,Si,Al和Ce等元素组成;初步探讨了复合膜的耐蚀机制。

Preparation and Properties of Silane-Rare Earth Composite Coating on Surface of Aluminum-Tube

Silane-rare earth composite coating was prepared by impregnation method at 60 ℃. The sample with a self-assembled monolayer of γ-aminopropyhfiethoxy (γ-APS) silane was immersed in the solution with cerium to get the complex coating. Corrosion resistance of aluminum tube surface with silane-rare earth composite coating was studied by electrochemical means, weight loss and salt spray test respectively. The results of linear potential sweep, Tafel curves and electrochemical impedance spectroscopy (EIS) indicated that the polarization resistance and self-corrosion current increased by two orders of magnitude, and impedance increased by two times, the corrosion resistant capability was improved significantly. The results of salt spray test showed that the anti-corrosion time increased by three times; Scanning electron microscope (SEM) observation showed that the composite coating was uniform and dense; X-ray en-ergy dispersive spectroscopy (EDS) test showed that the composite coating was mainly composed of N, O, Si, Al and Ce. The corro-sion protection mechanism of the composite coating was analyzed.