Electrochemical Behavior of AA2024-T3 Aluminum Alloy Anodized in Mixed Sulfuric and Carboxylic Acid Electrolytes

Durability and corrosion resistance are essential requirements in the development of aerospace components, and the optimization of anodizing processes stands out as an effective strategy to enhance the corrosion performance of aluminum alloys used in this sector. In this context, the present study provides new insights into the effect of the presence of different carboxylic acids (oxalic, citric, and succinic) in a sulfuric acid-based anodizing electrolyte on the corrosion resistance of the AA2024-T3 aluminum alloy. The anodic oxide films were characterized using microscopy and electrochemical analyses to assess their morphological and corrosion-resistant behavior. The results indicated the formation of oxide films with different surface morphologies, uniform thickness ranging from 16.7 to 23.8 µm, and satisfactory protection against corrosion in NaCl media (0.1 mol.L-1), especially with regard to treatment with oxalic acid (OSA), which, compared to other treatments with carboxylic acids (citric – CSA, and succinic – SSA) and the standard treatment (sulfuric acid – SA), maintained the highest protective performance of the coating over 21 days of immersion.