Kinetics of the electrolytic coloring process on anodized aluminum

Abstract

The kinetics of tin electrodeposition during the electrolytic coloring of porous anodic oxide films on aluminum is studied as a function of the oxide properties, e.g., the thickness of the porous oxide layer, and the surface resistance offered by the barrier oxide layer. While the thickness of the porous oxide layer is controlled by the anodization time, the surface resistance is controlled by the anodization voltage, and the anodization bath temperature. Steady-state polarization measurements are employed to characterize the dependence of the coloring kinetics on the oxide properties. Measurements indicate that the kinetics of the electrolytic coloring process can be accelerated by: (i) reducing the surface resistance of the oxide film (primarily offered by the barrier oxide layer) by growing the oxide at a lower anodization voltage, and/or a higher bath temperature, or (ii) growing a thinner porous oxide layer by decreasing the anodization time. The electrochemical measurements are supported by gravimetric analysis of electrolytically colored alumina samples (using calibrated wavelength-dispersive X-ray fluorescence spectroscopy), and by optical spectrophotometry.

Electrical behaviour, characteristics and properties of anodic aluminium oxide films coloured by nickel electrodeposition

“…6 lm. But similar results were also reported by Akolkar et al [39] working on tin deposition, showing that the brightness decreases as the tin content increases.…”

A Process for Etching Modulated Profiles

“…1 However, anodized aluminum is currently not widely used in the automotive industry for external body panels, in part because it cannot be easily finished and repaired. While anodized aluminum panels form a porous oxide layer that can be colored through a dyeing or plating process, [2][3][4][5][6][7][8] this implementation is limited by the difficulty in repairing damaged anodized aluminum panels. Damage to the oxide layer is visually undesirable and diminishes its mechanical and chemical resistance.…”

Electrochemically Engineered Nanoporous Materials

“…In an attempt to control the release properties of pSi surfaces, various surface chemistries have been used to prolong the drug/surface interactions and consequently slow the release [213]. In a study by Salonen et al [211] the release of five model drugs with different solubilities from thermally oxidized (TO) and thermally carbonised (TC) pSi MPs was monitored at different pH conditions, selected to represent the different conditions in the small intestine.…”

“…In this regard many AAO-NWs composites based on deposited metals such as Ag [33,[195][196][197][198][199][200][201][202], Au [200,[202][203][204][205][206][207], Co [110,208], Cu [209], Fe [210], Ni [107-109, 211, 212], and Sn [213] were investigated. In this regard many AAO-NWs composites based on deposited metals such as Ag [33,[195][196][197][198][199][200][201][202], Au [200,[202][203][204][205][206][207], Co [110,208], Cu [209], Fe [210], Ni [107-109, 211, 212], and Sn [213] were investigated.…”