超疏水船用铝合金表面微结构对耐海水腐蚀性能的影响

Effect of micro-structure of super-hydrophobic warship aluminum alloy surface on its corrosion resistance in seawater

为提高船用铝合金的耐海水腐蚀性能,利用激光在5083船用铝合金表面分别刻蚀点阵、直线、网格3种微结构,采用聚合物基纳米复合材料构建微纳双层结构,制备超疏水船用铝合金表面。采用光学显微镜和扫描电子显微镜表征其形貌;用接触角测量仪测量接触角和滚动角;采用电化学分析方法测试在海水环境中的耐腐蚀性能。结果表明,具有微纳双层结构的超疏水表面符合Cassie状态,且随着微结构间距的增大,接触角减小,滚动角增大,其耐海水腐蚀性能显著增强。间距为100μm的网格微结构表面具有最大的接触角157.8°和最小的滚动角0.57°,可将铝合金的腐蚀阻抗提高2个数量级。

In order to improve corrosion resistance of warship aluminum alloy in seawater,laser etching technique was used to build line,dot and grid micro-structure on the surface of 5083 warship aluminum alloy.Polymer-based nano-composites were coated on the microstructure to build the micro-nano structure for the super-hydrophobic surface of the aluminum alloy.The micrograph of the alloy was investigated by optical microscope and scanning electron microscopy.The contact angles and roll angles were measured by contact angle measurement.The corrosion resistance of the super-hydrophobic surface of the aluminum alloy in seawater was investigated by electrochemical impedance spectroscopy(EIS).The results show that the super-hydrophobic surfaces of the micro-nano structure fit the Cassie model,and the contact angles decrease with the spacing increment of the micro-structure,while the roll angles increase with the spacing increment.Its anti-corrosion ability is greatly improved.The surface with grid micro-structure of 100 μm spacing has a maximum contact angle of 157.8° and minimum roll angle of 0.57°,and its corrosion impedance enhances by two orders of magnitude.