AZ40镁合金在模拟海水介质中的腐蚀行为  

Corrosion behavior and mechanism of AZ40 magnesium alloy in simulated sea water

作　　者：李凌杰[1] 于生海[1] 雷惊雷[1] 王敬丰[2] 张胜涛[1] 潘复生[2] 

机构地区：[1]重庆大学化学化工学院 [2]重庆大学材料科学与工程学院,重庆400030

出　　处：《重庆大学学报（自然科学版）》2008年第6期702-706,共5页Journal of Chongqing University

基　　金：国家杰出青年科学基金资助项目(50725413);教育部留学回国人员科研启动基金资助项目(教外司留[2007]1108-6)

摘　　要：采用Tafel极化曲线、电化学阻抗谱方法研究了AZ40镁合金在模拟海水介质中的腐蚀行为,采用光学显微镜、扫描电子显微镜对腐蚀形貌进行了观察,结合介质pH值测量,讨论了腐蚀机理。结果表明,AZ40镁合金在模拟海水介质中的耐蚀性能较差;腐蚀自发发生,初期以点蚀为主要特征;由于Mg(OH)2等腐蚀产物存在较多缺陷,且分布不均匀,不能有效阻止腐蚀的发展,致使腐蚀扩展迅速,合金表面在短时间内就被严重破坏。Tafel polarization curve and electrochemical impedance spectroscopy （EIS） techniques were employed to investigate the corrosion behavior of AZ40 magnesium alloy in simulated sea water. The surface morphology of the alloy during exposure was observed with an optical microscope and a scanning electron microscope. The pH variation of bulk solution during corrosion was recorded. The results show that the major corrosin forms of AZ40 magnesium alloy in simulated sea water were characterized by pitting and filliform corrosion. The corrosion occurs spontanesously. The insovable corrosion products, which precip it ate on the alloy surface were characterized by porsity and hetorogeneity, indicating that these products can not prerent further alloy corrosion.. Therefore, the corrosion of AZ40 magnesium alloy spreads rapidly and the alloy surface is destroyed severely during short exposure period.

关 键 词：镁合金 腐蚀 模拟海水 

分 类 号：TG172.5[金属学及工艺—金属表面处理]