摘要
采用碱性硅酸盐溶液,在AZ91D镁合金试样表面制得微弧氧化膜,并利用电化学阻抗方法对镁合金及微弧氧化处理试样在3.5%NaCl溶液中的腐蚀行为进行比较研究.结果表明,镁合金经微弧氧化处理后,腐蚀电位和膜层阻抗均有一定程度的提高.但在浸泡过程中,微弧氧化处理试样的电化学参数呈现出不同的变化规律,初期波动较大,后期则逐渐降低,趋向稳定.
To investigate the influence of micro- arc oxidation （MAO） treatment, a layer of ceramic coating was prepared on AZ91D magnesium alloy by using MAO technique in alkali - silicate solution. The corrosion resistance of MAO treated and untreated AZ91D magnesium alloy was studied in 3.5mass% NaCI solution by means of the electrochemical impedance spectroscopy （EIS） method. During the immersion process, both specimens exhibited two kinds of impedance diagrams, two capacitive loops at the initial stage and one capacitive with one inductive loop at the later stage. Compared with the untreated magnesium alloy, the MAO treated specimen exhibited positive corrosion potential and increased resistance. Both the corrosion potential and the resistance of the MAO treated specimen fluctuated at the initial stage of immersion, afterwards decreased. A two - stage deterioration mechanism, the MAO coating deterioration and the Mg alloy localized corrosion, was proposed to describe the corrosion process of the MAO treated Mg alloy.
出处
《中国腐蚀与防护学报》
CAS
CSCD
北大核心
2006年第4期216-220,共5页
Journal of Chinese Society For Corrosion and Protection
关键词
微弧氧化
镁合金
腐蚀
电化学阻抗
micro - arc oxidation, Mg - alloy, corrosion, EIS
