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采用光学显微镜、扫描电镜、能谱仪、电化学阻抗谱测试结合超薄切片,分析阳极氧化2A97Al-Cu-Li合金在大气腐蚀前后的微观形貌、化学成分及电化学性能。结果表明:在不同温度利用含有硼酸-硫酸或酒石酸-硫酸组合的电解液生长膜层时,硼酸添加和较高温度允许较大的电流密度通过,使膜生长加速;对于不同电解液,孔的几何构形和结构相似;硼酸-硫酸阳极氧化试样在热带海洋大气环境中暴露1个月后,出现主要由O,Al,Cl,Cu组成的分散性黑色锈斑,表面产生白色沉淀;随着户外暴露时间的延长,合金发生严重的点蚀并深入合金内部,腐蚀的扩展与θ相粒子有关。
The microstructure, chemical composition and electrochemical properties of anodic oxidized 2A97Al-Cu-Li alloy before and after atmospheric corrosion were analyzed by optical microscope, scanning electron microscopy, energy dispersive spectroscopy and electrochemical impedance spectroscopy combined with ultrathin sections. The results showed that the addition of boric acid and higher temperature allowed the passage of larger current density to accelerate the film growth at different temperatures with the electrolyte containing boric acid-sulfuric acid or tartaric acid-sulfuric acid combination. For different electrolytes, The geometry and structure are similar. After exposure to the tropical marine atmosphere for one month, the boric acid-sulfuric acid anodic oxidation sample shows disperse black rust mainly composed of O, Al, Cl and Cu, and produces white precipitate on the surface. Outdoor exposure time, the alloy pitting and severe corrosion occurred within the alloy, the expansion of corrosion and θ phase particles.