Effect of aspect ratio of artificial pits formed on anodized Al by PRM on localized corrosion in chloride environments

摘要

New in solution type artificial pit formation with area selective electrochemical measurement technique was established. Artificial pits were formed on anodized 1070 aluminum in solutions by continuous focused pulse YAG laser beam irradiation. The aspect ratio (pit depth/pit width) of formed pit can be changed from 0.45 to 1.23 by controlling laser beam irradiation time. As applying constant potential while laser irradiation in chloride environments, localized dissolution was occurred only at the laser beam irradiated area, because of the anodic oxide film act as insulator. The corrosion current increases with increasing aspect ratio at the same applied potential, however, aspect ratio of the pit does not show an influence on repassivation behavior of 1070 aluminum alloy.