Characterization of nanoporous anodic aluminum oxide formed on laser pre-treated aluminum

- Laser pre-treatment of aluminum was performed.
- According to the operating conditions, the thickness of heat-affected zone and grain size varied.
- Laser pre-treated aluminum was anodized in sulfuric acid.
- No significant influence of the laser treatment of aluminum on anodic aluminum oxide nanopores was found.
- Laser pre-treatment did not spoil the arrangement of the alumina nanopores.

Technical purity aluminum was subjected to laser pre-treatment. Subsequently, self-organized anodization in sulfuric acid was performed in order to form nanoporous oxide layer. The influence of the laser pre-treatment operating conditions and grain size of the direct solidified aluminum on the formation of the nanoporous anodic aluminum oxide was studied on the base of FE-SEM images quantitative analyses. It was found there is no significant influence of laser pre-treatment on pore diameter, interpore distance and thickness of the grown oxide. Furthermore, fast Fourier transform-based quantitative image analysis showed that arrangement of the nanoporous alumina grown on the laser pre-treated aluminum is comparable to the arrangement of nanopores formed on high-purity aluminum without any pre-treatment. These findings were supplemented by the circularity analysis of the grown nanopores. This means that laser-treated aluminum elements can be anodized without significant decreases in the quality of the anodic oxides.