Patterning polycrystalline aluminum by electropolishing at low voltages

Highly ordered stripes with controllable spacing of the pattern lines are obtained during electropolishing aluminum (Al) foils at low voltage. The samples are investigated in detail with the Atomic Force Microscope (AFM). Stripes with similar spacing of the pattern lines are observed on the surface of Al sheets which are electropolished in the same electrolyte at various voltages. However, the spacing of the pattern lines is closer when there is more ethanol in the electrolyte at the same voltage. The formation mechanism of stripes with dissimilar spacing of the pattern lines in different electrolyte is discussed. We suggest that the spacing of the pattern lines depends on the concentration of the polar molecules (ethanol) in the electrolyte.