Effect of the Anodizing Temperature on Microstructure and Tribological Properties of 6061 Aluminum Alloy Anodic Oxide Films

Abstract

Anodizing a simple and effective method to improve the wear resistance of 6061 aluminum alloy. In this study, the microstructure of 6061 aluminum alloy oxide films (AAO) was adjusted by changing the electrolyte temperature (5, 15, and 25 °C) using 160 g/L sulfuric acid as the electrolyte. The phase composition, microstructure, and morphological characteristics of the specimens were detected using X-ray diffractometer and field emission scanning electron microscopy (SEM). The hardness, elastic modulus, and tribological properties of the films were examined using hardness testers and a rotary friction tester. The results showed that as the temperature of the electrolyte increases, the surface of the oxide films changes from uniformly distributed small-sized pores to a coral-like loose porous structure, and the thickness of the films increases. The electrolyte temperature has a significant effect on the friction performance of the AAO films. When the solution temperature decreases from 25 to 5 °C, the steady-state friction coefficient decreases from 0.46 to 0.39. According to the morphology of the wear tracks, it can be determined that the main wear mechanism of AAO films gradually changes from delamination wear to abrasive and adhesive wear, and the wear rate drops by ~69%.

Fatigue Resistance of an Anodized and Hardanodized 6082 Aluminum Alloy Depending on the Coating Thickness in the High Cycle Regime

“…[ 20,33 ] The generally higher hardness of the hard anodic coatings is a result of their denser pore structure, when compared to the anodized specimens. [ 34 ] Kwolek et al [ 35 ] also observed a decrease in hardness with an increase in the thickness of a hardanodic coating, but they give no further explanation.…”

Generating porous metal surfaces as a mean to incorporate thymol-loaded nanoparticles

“…Etching processes in aluminum were previously described for different acid solvents; however, obtaining nanoporous structures remains a challenge, since most large micropores were obtained using hydrochloric acid (HCl) [ 21 , 22 ], or even using oxalic acid/phosphoric acid mixtures (C 2 H 2 O 4 /H 3 PO 4 ) [ 23 ]. On the other hand, nanopores were obtained using an anodizing process involving sulfuric acid (H 2 SO 4 ) dipping [ 24 ]; however, the small dimensions of the pores prevented the further deposition of nanoparticles. In our case, when we used HNO 3 (35% during 35 min) as the etching chemical to obtain nanopores via a simple dipping process, a homogeneous structure with pore sizes of ~ 30 nm was formed enabling the deposition of mPEG-b-PLA micelles.…”

Optimizing the Operational Parameters Used in Preparing Anodic Aluminum Oxide (AAO) Templates from Low-purity Aluminum

“…Tsyntsaru et al 7 reported these precipitates are caused by the alloying elements, such as Si in the aluminum foil. The oxygen bubbles can form and burst during the electrochemical process at the oxide/electrolyte interface as explained by Feng et al 24 The presence of these defects is not significant for the suggested target applications.…”