AZ91D镁合金复合涂层在NaCl溶液中的腐蚀行为
Corrosion Behavior of Composite Coating on AZ91D Alloy Surface in NaCl Solution
曾立云1,2, 杨世伟1, 曹建会2, 杨武希2
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作者单位:1. 哈尔滨工程大学 材料科学与化学工程学院, 黑龙江 哈尔滨 150001; 2. 中国航天科工集团公司 第八三五七研究所, 天津 300141
中文关键字:复合涂层; 镁合金; 极化; 电化学阻抗谱
英文关键字:composite coating; Mg alloy; polarization; EIS
中文摘要:利用微弧氧化和化学镀镍在AZ91D镁合金表面制备了复合涂层,采用动电位极化曲线测试和电化学阻抗测试等方法研究微弧氧化和化学镀镍复合涂层在3.5%NaCl溶液中的腐蚀行为。结果表明,复合涂层使基体镁合金的腐蚀电位提高了1.339 V,自腐蚀电流密度降低为基体的1/10; 在浸泡初期和中期,复合涂层通过阻碍腐蚀介质向基体的传质和腐蚀产物的输运提高了镁合金的耐腐蚀性,经270 h的浸泡,复合涂层完全失效。
英文摘要:The composite coating on AZ91D alloy surface was prepared by plasma electrolytic oxidation and electroless plating process. The corrosion resistance of the composite coating was analyzed by potentiodynamic polarization and electrochemical impedance spectroscopy. The results show that the corrosion potential improves by 1.339 V. The self-corrosion current density decreases to 1/10 of the AZ91D alloy. The corrosion resistance of the composite coating improves by the blocking of transportation of corrosion medium and the products. The coating becomes failure after immersion in 3.5% NaCl solution for 270 h.