((中南大學 材料科學與工程學院，長沙 410083))
摘 要: 采用分子自組裝的方法在Mg-Gd-Y-Zr合金表面制備雙-(γ-三乙氧基硅丙基)四硫化物硅烷薄膜。通過傅立葉變換紅外光譜研究薄膜結(jié)構(gòu)特性，用掃描電鏡觀察薄膜表面形貌，并用電化學極化曲線和交流阻抗測試研究薄膜的耐蝕性能。結(jié)果表明，鎂合金表面薄膜通過SiOSi鏈接形成網(wǎng)狀結(jié)構(gòu)，并可能通過形成SiOMg界面相結(jié)構(gòu)與鎂合金表面連接；晶界上薄膜厚度小于其他各處；薄膜將腐蝕電流密度降低2個數(shù)量級以上，明顯提高了鹽水浸泡過程中的阻抗值。
關(guān)鍵字: Mg-Gd-Y-Zr合金；硅烷；薄膜；腐蝕
（(School of Materials Science and Engineering, Central South University, Changsha 410083, China)）
Abstract:Bis-[triethoxysilylpropyl]tetrasulfide silane thin film was prepared, first by self-assembling the silane in solution of ethanol and deionized water and then aged at 120 ℃ for 60 min, on surface of Mg-Gd-Y-Zr magnesium alloy for improvement of its corrosion resistance. Fourier transform infrared spectroscopy (FTIR) was used for structural characterization of the formed silane film. Scanning electron microscope (SEM) was used for observing surface morphology of the film. Electrochemical potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) were used for evaluating the corrosion performances of the film. The results demonstrate that the film is cross linked through SiOSi, which is linked to surface of the Mg alloy through formation of interphases possibly as SiOMg. The film on the grain boundary of the magnesium alloy is thinner than those of other areas. The corrosion current density of silane treated Mg alloy is reduced by above two orders of magnitude than that of the bare alloy. The impedance values of silane treated Mg alloy, especially at the low frequency, are promoted by the silane film during the immersion in 3.5% NaCl solution till 24 h.
Key words: Mg-Gd-Y-Zr alloy; silane; film; corrosion
