Pitting corrosion resistance of ultrafine-grained aluminum processed by severe plastic deformation
Pitting corrosion resistance of ultrafine-grained aluminum processed by severe plastic deformation
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剧烈塑性变形加工超细晶铝的耐点蚀性能
DOI：
10.2320/matertrans.47.1163
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发表时间：
2005
影响因子：
1.2
通讯作者：
Z. Horita
中科院分区：
文献类型：
--
作者：
I. Son;Hiroaki Nakano;S. Oue;Shigeo Kobayashi;H. Fukushima;Z. Horita
通过在含300 ppm Cl -溶液中的极化曲线和表面分析，研究了等通道转角挤压（ECAP）对Al和Al-Mg合金抗点蚀性能的影响。经ECAP处理后，Al和Al-Mg合金的点蚀电位明显向贵金属方向移动，表明ECAP处理提高了合金的抗点蚀能力。SEM观察表明，点蚀发生附近的杂质沉淀和沉淀的杂质的尺寸作为ECAP过程的结果减少。腐蚀电位的时间依赖性和极化电阻使用交流阻抗技术确定的ECAP过程中增加的Al氧化膜的形成速率。Al和Al-Mg合金经ECAP后抗点蚀性能的提高主要归因于杂质沉淀物尺寸的减小和Al氧化膜形成速率的提高。
The effect of equal-channel angular pressing (ECAP) on the pitting corrosion resistance of Al and Al-Mg alloy was investigated by means of polarization curves in solutions containing 300 ppm of Cl - and by surface analysis. The potentials for pitting corrosion of Al and Al-Mg alloy were clearly shifted in the noble direction by the ECAP process, indicating that this process improves resistance to pitting corrosion. SEM observations revealed that pitting corrosion occurred near impurity precipitates and that the size of the impurity precipitated decreased as a result of the ECAP process. The time-dependence of corrosion potential and the polarization resistance determined using the AC impedance technique suggest that the ECAP process increases the rate of formation of Al oxide films. The improvement in pitting corrosion resistance of Al and Al-Mg alloy by ECAP appears to be attributable to a decrease in the size of impurity precipitates and an increase in the rate of formation of Al oxide films.