Effects of the Process Conditions on the Color of Dye-Treated Anodized AA5052.

This study investigated the effects of process conditions (anodization time, coloring treatment time, dye concentration) on the color of dye-treated anodized aluminum alloy 5052 (AA5052). The color change of the anodic layers and amount of dye adsorbed were quantitatively analyzed using a UV-vis spectrophotometer. The color of the anodic layer turned darker as the anodizing time, coloring treatment time, and dye concentration increased due to the amount of dye adsorbed by the layers. As the anodizing time increased, the thickness of the anodic layers also increased, and a growth in the number of nanopore sites resulted in a greater amount of dye being adsorbed, causing the darkening of the color. Increase in the coloring treatment time and dye concentration led to a greater amount of dye being adsorbed in the anodic layers, thereby contributing to the darkening of the color. Quantitative analysis in the depth direction of the anodic layer using glow discharge optical emission spectroscopy revealed that the dye was mostly adsorbed on the outer region of the anodic layer.