Corrosion behavior of aa2055 aluminum-lithium alloys anodized in the presence of sulfuric acid solution

Abstract

The aim of this work was to evaluate the corrosion behavior of the AA2055 Aluminumlithium alloy anodized in a sulfuric acid (H2SO4 ) bath, varying the current density of 0.19 and 1 A·cm−2 and why the sealing solution was water (H2O) and sodium dichromate (Na2Cr2O7 ). Anodized samples were exposed to a 10 vol.% H2SO4 solution and the electrochemical technique used was electrochemical impedance spectroscopy. Scanning electron microscopy and X-ray photoelectron spectroscopy were employed to characterization of the anodizing layer, determinate morphology and thickness of coatings. The Na2Cr2O7 sealing solution tends to increase the charge transfer resistance and produces a more homogeneous and compact passive oxide layer, and imparts a corrosion inhibition protection to the AA2055. SEM observations indicated that the morphology and thickness of the anodic films formed on AA2055 aluminum-lithium alloy anodized have the best results for both current densities.