材料期刊网

研究了阴极下限电位和阴极半周时间对高纯铝在2mol/L HCl 溶液中三角波动电位初期的伏安特性和表面形貌的影响。随阴极下限电位的负移，阳极溶解电流快速减小，腐蚀箔表面蚀坑直径和密度明显降低；但在同一阴极下限电位时，随阴极半周时间的延长，阳极电流则缓慢降低。蚀坑直径无显著变化，蚀坑密度却大提高。当阴极下限电位低于-2.4V vs SCE时，阳极电流首先从一较小值逐渐增大到一最大值，然后随循环数的增加又不断减至很小，腐蚀箔表面可见蚀坑很少。实验结果表明，阴极下限电位是决定铝阳极溶解程度和表面形貌的关键因素，尽管阴极时间也发挥一定的作用；阴极析氢过程对铝的阳极点蚀具有促进和阻阻碍的双重作用。

The effects of cathodic potential limits and cathodic period on voltammetric characteristics and surface morphology of aluminum in 2mol/L HCl solution at 25℃ were investigated by cyclic triangularwave potentiodynamic method over the potential range from 0.0 to -2.6V vs SCE and SEM analysis of aluminum surface after 200 cycles.The results showed that the magnitude of anodic pitting current decreased rapidly with cathodic potential limit going towards negative,leading to an obvious decrease in the size and density of pits on aluminum.At the same cathodic potential limit,however,the current diminished slowly with increase in the cathodic period,resulting in less change in the size, but significant increase in the density of pits.As cathodic limit became more negative than abort -2.4V vs SCE,the anodic current initially increased, reached a maximum value,and started decreasing to a megligible value,few small pits on aluminum surface were observed by SEM at higher magniication.This result suggested that cathodic potential limit was a key factor in determining anodic dissolution and surface morphology of aluminum although the cathodic time also affect anodic current to a certain extent.Also the process of hydrogen evolution during cathodic half cycle played a dual role (i.e.promotion and impediment) in anodic pitting during AC etching of aluminum.