Influence of anodization parameters on film thickness and volume expansion of thick- and large-sized anodic aluminum oxide film

Abstract

Anodic aluminum oxide (AAO) lm with a thickness ranging from 20 to100 μm was prepared by using a large-sized Al plate (4 cm × 10 cm) to investigate the anodization parameter effect on the lm thickness and volume expansion factor. A corrosion treatment (voltage = 0 V) was performed to investigate the lm dissolution caused by acid. The actual anode surface temperature was also measured to con rm the eld-assisted nature of AAO dissolution. The lm thickness increases exponentially with temperature, and increases approximately linearly with voltage, duration or concentration. The volume expansion factor gives a rst rising and then falling trend with temperature or duration, while it has a nearly linear trend with voltage or concentration. The volume expansion factor increases with the intensi ed electric eld, while its decrease is attributed to the Joule heat-enhanced dissolution. In the case of large lm thickness (> 20 μm), the pore con nement effect may be one of the reasons for the change of volume expansion factor. In addition to the conventional parameters, the heat transfer-related parameters such as sample size also greatly affect the AAO lm growth.

Galvanic Corrosion of AA5083/Fe in Diluted Synthetic Seawater: Effect of Anodizing on Local Electrochemistry on and around Al 6 (Fe,Mn) on Al-Matrix

“…However, at 16 V, the surface film on the Al 6 (Fe, Mn) was thinner than the one formed at 8 V. Oxide films formed on pure Al and Al alloys exhibit dielectric properties. 50 Moreover, it is known that the surface film thickens with increasing applied anodizing voltage to approximately 100 V. [51][52][53] However, at higher anodizing voltages, surface oxide films formed on Alcontaining IMPs reportedly exhibit nanoporous structures, [54][55][56][57] which may be why the oxide film did not systematically thicken on the Al 6 (Fe, Mn) surface. This suggests that a film thicker than 170 nm is required for Al 6 (Fe, Mn) to prevent the galvanic corrosion of the AA5083.…”

Nanocones: A Compressive Review of Their Electrochemical Synthesis and Applications

“…The anodization process allows for the fabrication of Al2O3 as parallel nanopores [64] that are perpendicular to the Al surface. The geometrical properties of hexagonal cells in AAO, i.e., pore diameter and height and the interpore distance, can be controlled by applying different process conditions like the electrolyte and its concentration [65][66][67], temperature [68][69][70], voltage [71][72][73], and duration of the anodization [74,75]. The two-step anodization process produces an AAO matrix with nanoconical pores.…”

Investigation on the multiple plies structure of aluminum-lithium alloy and glass fiber composite with respect to deformation failure

“…These films are most likely anodic due to aluminum alloy can form compact after the electrochemical reaction. These Anodic aluminum oxide (AAO) film with a thickness ranging from 20 to 100 μm [43].…”