CORROSION AND TRIBOCORROSION PERFORMANCE OF COMMERCIAL ANODIZED ALUMINUM ALLOYS

In this work were studied two commercial anodized aluminum alloys under conditions of corrosion and tribocorrosion. For two different types of anodizing electrolyte (H2SO4 and H2C2O4), a constant value of current density and two anodizing time (30 and 45 minutes) were used. Using techniques of Scanning Electron Microscopy (SEM) with Spectroscopy Energy Dispersive X-Ray (EDS) coupled, were characterized the alloys and morphologies of the surfaces formed in the oxide layers. Results obtained show large differences between the condition of anodized (A1) in sulfuric acid for 45 minutes in AA6061 alloy and anodized condition (D1) for the same time in oxalic acid for alloy AA8011. For sample (A1), the results reveals the formation of a morphology named "smudge" which is characteristic of the electrolytic solution used and for this case the average thickness was 5,95 +/- 0,02 mu m. For sample (D1), the average thickness was 3,14 +/- 0,02 mu m and revealing the generation of cavities along all surface area. Both corrosion tests in salt spray chamber, electrochemical potentiodynamic polarization and tribocorrosion found that the best behavior was obtained for sample (A1), with lower, average mass gain, corrosion current density and friction coefficient. The performance in all anodizing conditions was improved comparing against samples without anodized.