纯铝在氯化钠热水溶液中电化学行为的研究

Electrochemical behavior of aluminum in NaCl solution at high temperature

通过电化学分析方法研究了经不同表面处理的纯铝在90℃下,3.5%氯化钠溶液中的电化学行为及特点.结果表明,经阳极氧化法处理后的纯铝的耐蚀性远优于未经任何处理的样品;对于经过阳极氧化处理的样品,沸水封孔的试样耐蚀性明显优于未封孔的试样;在相同处理时间,不同电流密度下,随着电流密度的增加,样品点蚀电位不断增加,试样的抗点蚀能力增强;在相同电流密度,不同处理时间下,试样的点蚀电位随时间的增加呈不断下降的趋势,表明点蚀容易发生.最终得到,在阳极氧化电流密度为2 A/dm2,时间为10 min的条件下,试样表面处理工艺最佳.

The electrochemical behaviors and characteristics of samples with different surface treatments were studied by electrochemical analysis in 3.5 % NaCl solution at 90 ℃.The corrosion resistance of aluminum was greatly enhanced through anodic oxidation,meanwhile the corrosion resistance of anodized and sealed aluminum is much better than those unsealed.Under the same treated time,the pit potential will be in the same direction to that of the current density increasing and the pits are not easily to be found on the surface of aluminum.With the same current density,the pit potential will be a downward tendency as treated time increasing,which indicates the pit is liable to occur.The best treatment is current density of 2 A/dm2 for 10 min.