Anodization of cold deformed technical purity aluminum (AA1050) in oxalic acid

Technical purity aluminum (AA1050) was subjected to a cold rolling process up to 80% of thickness reduction. So prepared samples were anodized in 0.3 M oxalic acid at the voltage ranging from 20 to 60 V. On one hand, no significant changes in current density, or thickness of the formed oxide were noticed. On the other hand, a cold deformation of aluminum before the self-organized two step anodization caused formation of additional pores, among the hexagonal ones (anodization at 30 V of aluminum rolled to the thickness reduction of 80%). Moreover, cold rolling of aluminum before anodization caused interpore distance decrease (30 V) or increase (50-60 V), with relevant pore density increase and decrease. Additionally, fast Fourier transform based quantitative arrangement analysis revealed that rolling of aluminum prior to the anodization spoils the pore ordering. The results show clearly that substrate also plays an important role in the self-organized anodization.