Synergistic effect between 8-hydroxyquinoline and benzotriazole for the corrosion protection of 2024 aluminium alloy: A local electrochemical impedance approach

Abstract

This work is devoted to the corrosion inhibition of the 2024 aluminium alloy(AA2024) in neutral aqueous solution by 8-hydroxyquinoline (8-HQ) and benzotriazole (BTA). First, current-voltage cmves and global electrochemical impedance measurements confirmed that 8-HQ and BTA are two effective corrosion inhibitors for AA2024. Mixing the two compounds led to a synergistic effect for the corrosion protection of the alloy. From the impedance data analysis, it was shown that 8-HQ acted mainly on the aluminium matrix with an additional action of the BTA on the intermetallic particles. Then, to analyse the rote of the inhibitors on thegalvanic coupling between the aluminium matrix and the particles, local electrochemical impedance measurements were performed on a mode! system (Al/Cu couple). lt was shown that in the presence of 8-HQ or BTA atone, the galvanic coupling between copper and aluminium was little reduced white in the presence of both compounds together it was strongly limited. The local impedance results confirmed the specific inhibition of the 8-HQand of the BTA on Al and Cu respectively.

8-hydroxyquinoline-modified clay incorporated in an epoxy coating for the corrosion protection of carbon steel

“…By comparison with our previous studies, the solvent epoxy resin was replaced by a solvent free system [26 28]. 8HQ is known for its chelating properties on different metals and as corrosion inhibitor of copper [29], of magnesium [30], of aluminium [31,32] and of carbon steel [33]. An alkyl quaternary ammonium salt modified MMT was compared with the 8HQ MMT.…”

Evaluation of the anticorrosion of waterborne epoxy coatings containing cerium salt-activated ceria nanoparticles deposited onto carbon steel substrates

“…In recent years, numerous researches have been investigated focused on development of new effective and environment-friendly corrosion inhibitors [10][11][12]. However, when inhibitors are directly added into coating systems, it can conduce to undesired leaching of these compounds and the coating will be degraded [13,14].…”

A local electrochemical impedance study of the self-healing properties of waterborne coatings on 2024 aluminium alloy

“…The Al/Cu couple was first designed by Jorcin et al [9] to study corrosion phenomena associated with copper rich intermetallic particles in aluminium alloys. Local impedance measurements were also performed on the Al/Cu couple to analyse the role of different inhibitors on the galvanic coupling [13,14]. For example, it was shown that the galvanic coupling was strongly limited by mixing 8 hydroxyquinoline and benzotriazole which was not the case when the inhibitors were used separately [14].…”

“…Local impedance measurements were also performed on the Al/Cu couple to analyse the role of different inhibitors on the galvanic coupling [13,14]. For example, it was shown that the galvanic coupling was strongly limited by mixing 8 hydroxyquinoline and benzotriazole which was not the case when the inhibitors were used separately [14]. Inductive loops, consistently observed on the local impedance diagrams during galvanic couplings, were attributed to the local ohmic impedance [10].…”