Mg-Al系和Mg-RE系合金在NaCl溶液中的腐蚀电化学行为

来源期刊：中国有色金属学报2009年第10期

论文作者：丁文江 向亚贞 常建卫 彭颖红

文章页码：1713 - 1719

关键词：AZ91D镁合金；Mg-RE合金；腐蚀行为；循环极化

Key words：AZ91D Mg alloy; Mg-RE alloy; corrosion behavior; cyclic polarization

摘    要：采用盐水浸泡法和电化学方法研究AZ91D镁合金和稀土镁合金Mg-3.0Nd-0.2Zn-0.4Zr(NZK)在5%(质量分数)NaCl溶液中的腐蚀行为。结果表明：NZK的腐蚀速率仅为AZ91D镁合金的1/2，这主要是由于NZK中阴阳极之间的电位差和阴阳极面积比小于AZ91D的所致；AZ91D的腐蚀主要集中在局部区域，形成较深的腐蚀坑，而NZK的腐蚀沿合金表面进行，形成比较均匀的浅腐蚀区域；NZK的腐蚀电位低于AZ91D的腐蚀电位； NZK稀土镁合金的耐点蚀能力高于AZ91D的。

Abstract: The corrosion behaviour of AZ91D and Mg-3.0Nd-0.2Zn-0.4Zr (mass fraction, %) alloy was investigated in 5% (mass fraction) NaCl solution by immersion test and electrochemical measurements. The immersion test shows that the corrosion rate of NZK is only half of that of AZ91D, which is attributed to the higher potential difference of the cathode-to-anode phase and the anode matrix and higher cathode-to-anode area ratio of AZ91D than those of NZK. The corrosion of AZ91D concentrates on the certain areas and results in much deeper corrosion pits, while that of NZK spreads across the surface and leads to more uniform and shallow corroded areas. The corrosion potential of NZK is much lower than that of AZ91D indicated by the open circuit potential measurement. The cyclic polarization curves show that NZK alloy has higher pitting corrosion resistance than AZ91D.

基金信息：国家重点基础研究发展计划资助项目
中国博士后科学基金资助项目
上海市优秀学科带头人计划资助项目