化学学报 ›› 2012, Vol. 70 ›› Issue (20): 2179-2186.DOI: 10.6023/A12050194 上一篇    

研究论文

LC4铝合金表面电泳沉积硅锆有机-无机杂化涂层的制备及性能

刘建华, 董琳, 于美, 李松梅, 詹中伟   

  1. 北京航空航天大学材料科学与工程学院 北京 100191
  • 收稿日期:2012-05-14 出版日期:2012-10-28 发布日期:2012-08-27
  • 通讯作者: 刘建华 E-mail:liujh@buaa.edu.cn

Preparation and Properties of Silicon-Zirconium Hybrid Coatings by Electrophoretic Deposition on LC4 Aluminum Alloy

Liu Jianhua, Dong Lin, Yu Mei, Li Songmei, Zhan Zhongwei   

  1. School of Materials Science and Engineering, Beihang University, Beijing 100191, China
  • Received:2012-05-14 Online:2012-10-28 Published:2012-08-27

采用阴极电泳沉积的方法在LC4铝合金表面制备硅锆有机-无机杂化涂层, 并探讨了电泳沉积条件对涂层形貌、结构以及耐蚀性的影响. 采用纳米粒度仪检测了不同硅锆杂化溶胶的zeta电位; 采用扫描电子显微镜(SEM)和原子力显微镜(AFM)观察了涂层的表面微观形貌和粗糙程度; 采用傅里叶红外光谱(FTIR)研究了涂层的化学结构; 采用电化学方法研究了沉积电压对涂层耐蚀性能的影响, 进而探讨了电泳沉积增强杂化涂层耐蚀性的机理. 结果显示沉积体系的pH为1.6、沉积电压为5 V时为最佳的沉积条件, 所获得的硅锆有机-无机杂化涂层表面均匀致密性最好, 粗糙程度和耐蚀性都得到了明显的改善, 在3.5% NaCl溶液中体现出较好的耐蚀作用.

关键词: 电泳沉积, 有机-无机杂化, 涂层, 沉积电压, 铝合金

Silicon-zirconium hybrid coatings were prepared by cathode electrophoretic deposition (EPD) method on the surface of LC4 aluminum alloy. The influence of deposition conditions on the morphology, structure and corrosion resistance of the hybrid coatings was studied. Silicon sol and zirconium sol with a molar ratio Si/Zr=3∶1 were prepared separately and then mixed. The silane solutions used here consist of GTMS (3-glycidoxypropyltrimethoxysilane) and absolute ethanol and deionized water mixed solvent, with pH adjusted by acetic acid. The obtained solutions were vigorously stirred at room temperature for 1 h. On the other hand, TPOZ (zirconium n-propoxide) was complexed with ethyl acetoacetate and diluted with absolute ethanol up to a molar ratio ethanol/H2O=3∶1. The Zr-solution was stirred for 1 h at room temperature. After then Si-solution and Zr-solution were mixed under stirring at room temperature for 30 min. Two-electrode system in which Plumbum and LC4 aluminum alloy as the anode and the cathode respectively was applied for the deposition of silicon-zirconium organic-inorganic hybrid coatings. The electrodeposition was mainly carried out at different cathodic potentials (0, 2, 5, 10, 20 V, respectively), for 10 min. Finally the silane films were dried at room tempreture and then cured at 60 ℃ for 2 h, 90 ℃ for 30 min, 100 ℃ for 15 min at air atmosphere in an oven. Further heat treatment provides the thermal energy for the condensation reaction. The zeta potential of different solution was measured by nano-particle size analyzer. The morphology and roughness of the hybrid coatings were detected by using scanning electron microscopy (SEM) and atomic force microscope (AFM), respectively. The chemical structure of the silicon-zirconium hybrid coatings was investigated by using Fourier transform infrared spectroscopy (FTIR). The corrosion resistance of the hybrid coatings was studied by electrochemical impedance spectroscopy (EIS). Finally, the corrosion resistance mechanism of the coatings was discussed. The results showed that the optimum pH of the hybrid solution was 1.6 and the best cathode voltage was 5 V, under which the hybrid coatings are of best performance with uniform surface, dense structure, less roughness, and excellent corrosion resistance in 3.5% NaCl solution.

Key words: electrophoretic deposition, organic-inorganic hybrid, coatings, deposition potential, aluminum alloy