硼酸-硫酸阳极氧化2A97Al-Cu-Li合金在热带海洋大气环境中的初期腐蚀机理  

Mechanism of Early Stage Corrosion for Boric-sulfuric Acid Anodized 2A97Al-Cu-Li Alloy Under Tropical Marine Atmosphere

作　　者：骆晨[1] Sergiu P.Albu 孙志华[1] 汤智慧[1] 陆峰[1] Xiaorong Zhou 

机构地区：[1]北京航空材料研究院航空材料先进腐蚀与防护航空科技重点实验室,北京100095 [2]曼彻斯特大学材料学院

出　　处：《材料工程》2016年第9期8-15,共8页Journal of Materials Engineering

基　　金：国家自然科学基金资助项目(51201157);国防科技工业技术基础科研项目(H052013A003)

摘　　要：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。Optical microscopy（OM）,scanning electron microscopy（SEM）,EDX and EIS combined with ultramicrotomy were employed to investigate the micro morphology,chemical composition and electrochemical properties of anodized 2A97 Al-Cu-Li alloy before and after atmospheric corrosion.The results show that when electrolytes containing combinations of tartaric-sulfuric or boric-sulfuric acid are used to grow the films at different temperatures,boric acid addition and higher temperature allow for higher current density that speeds up the film growth.The pore geometry and structure is similar for different electrolytes.Dispersive dark rusty spots composed of O,Al,Cl,Cu are present on the boric-sulfuric acid anodized specimen after exposure in tropical marine atmosphere for 1month.Deposition of white corrosion product is found on the specimen surface as well.Severe pitting occurs and develops deeply into the alloy substrate after elongated outdoor exposure.Corrosion propagation is associated withθ-phase particles.

关 键 词：硼酸-硫酸阳极氧化 AL-CU-LI合金 大气腐蚀 点蚀 

分 类 号：TG174.4[金属学及工艺—金属表面处理]