Synergistic Inhibition Effect of Rare Earth in the Corrosion of the AA2024-T3 and CFRP in Galvanic Couple

Abstract

Inhibition effect of LaN₃O₉.6H₂O, 3-amino-1,2,4-triazole (ATA) and 5-chlorobenzotriazole (5-Cl-BTA) at various concentrations (0.5, 2, 4 and 6) was analyzed to observe the corrosion behavior of the AA2024 in galvanic couple with CFRP using zero resistance ammeter and electrochemical impedance spectroscopy (EIS). A solution of 0.05 M NaCl was used as electrolyte. Results have shown that the addition of LaN₃O₉.6H₂O at different concentration decreased the current density up to 21 h of exposition at the aggressive media, with a trend of decrease trough the time. Moreover, modulus of impedance showed that the electron flow decreased in the presence of La3+, rising its maximum efficiency at 6mM with a value of 92%. Furthermore, 5-Cl-BTA presented its highest efficiency at 6mM with a value of 72%.