The effects of pore widening and calcination on anodized aluminum oxide prepared from Al6082

In this study, semi-organized anodized aluminum oxide (AAO) is prepared by two-step anodization in oxalic acid using a low-purity aluminum (Al) alloy (Al6082) as the source material. Obtaining ideally ordered AAO layers from Al alloys is confounded by the presence of impurities and requires specialized post-anodization treatment. Here, a process is proposed for obtaining an AAO layer with a semi-ordered pore arrangement by means of calcination and pore-widening procedures. Calcination temperatures of 400-600 degrees C and pore-widening times of 15-120 min were explored. It was found that calcination improved the pore order of AAO layers from disordered to semi-ordered (defined as being near ideally ordered-one pore surrounded by six neighboring pores). In addition, it was found that calcination at 600 degrees C resulted in suitable pore widening of the AAO layer. The morphology of the AAO layers was characterized using scanning electron microscopy, which was applied to determine pore diameter, inter-pore distance, pore density, and AAO layer thickness. We found that calcinated and pore-widened AAO layers with pore diameters of 48.7 nm, inter-pore distances of 80.6 nm, and pore densities of 178 pores/mu m(2) could be prepared. The AAO preparation method proposed here is an economically attractive process suitable for the preparation of AAO layers due to the utilization of an inexpensive Al source.