镁合金表面碳纳米管/硅烷复合膜的耐蚀性能

Corrosion resistance of carbon nanotubes/silane composite coatings on AZ91D magnesium alloy

为了进一步改善AZ91D镁合金表面单一硅烷膜的耐蚀性能,将不同含量碳纳米管添加到γ-氨丙基三乙氧基硅烷(KH-550)溶液中,借助简单浸渍法在其表面制备了碳纳米管/硅烷复合膜。通过点滴试验、中性盐雾试验、全浸腐蚀试验和E-t曲线测试评价了复合膜的耐蚀性能。结果表明:与单一硅烷膜相比,碳纳米管/硅烷复合膜的致密性较高,有效地阻挡了侵蚀性介质向基体的渗透,显著提高了AZ91D镁合金的耐蚀能力;随着碳纳米管含量的增加,碳纳米管/硅烷复合膜的耐蚀性能先上升后下降,当碳纳米管含量为0.3 g/L时复合膜的耐蚀性能最佳。

In order to further improve the corrosion resistance of the single silane coating on AZ91 D magnesium alloy,which was treated in γ- APS solution with different concentrations of the carbon nanotubes,the carbon nanotubes/silane composite coatings were prepared. The corrosion resistance of the composite coatings were evaluated by drop test,neutral salt spray test,immersion corrosion test and potential-time curve test.The results revealed that the compactness of the carbon nanotubes/silane coatings were higher than the single silane coating,which significantly improved the corrosion resistance of AZ91 D magnesium alloy by effectively blocking the infiltration of corrosive medium to the substrate.With the increase of the concentrations of the carbon nanotubes,the corrosion resistance of the carbon nanotubes/silane composite coatings first increased and then decreased.The carbon nanotubes/silane composite coatings had the optimum corrosion resistance when the concentration of the carbon nanotubes was 0.3g/L.