Electrochemical techniques for practical evaluation of corrosion inhibitor effectiveness. Performance of cerium nitrate as corrosion inhibitor for AA2024T3 alloy

Evaluation of Inhibitor Performance by Electrochemical Methods: Comparative Study of Nitrate Salts on AA 2024-T3

“…Importantly, the surface of the alloy immersed in the environment with the higher inhibitor concentration appeared more corroded that the surface of the alloy immersed in the environment without the inhibitor. The addition of Co(NO 3 ) 2 to the 3.5% NaCl environment had an effect similar to that revealed for Ce(NO 3 ) 3 . The specimens immersed in the environment with a low concentration of inhibitor presented impedance values significantly higher than the specimen immersed in the absence of the inhibitor.…”

“…Manganese-based conversion coatings were used on aluminum alloys and pure aluminum, providing corrosion protection by forming a protective layer. 15,16 Although studies on the inhibition performance of each of the above mentioned compounds are abundant in the literature, comparative studies are less common.12 Further, the techniques used for the assessment of the performance vary widely, ranging from potentiodynamic polarization 17,18 to electrochemical impedance spectroscopy 3,17 and salt spray testing 19 which are generally performed in environments and with inhibitor concentrations that are not directly comparable.This work aims to illustrate the advantages in using image-assisted electrochemical noise analysis 20-22 compared to more traditional approaches, such as potentiodynamic polarization, in order to comparatively evaluate the effectiveness of corrosion inhibitors. Additionally, in this study, corrosion testing was systematically conducted in environments containing relatively high amounts of chlorides (3.5 wt%) and low concentrations of inhibitors (mM) in order to evaluate the performance under demanding conditions.…”

“…12 Further, the techniques used for the assessment of the performance vary widely, ranging from potentiodynamic polarization 17,18 to electrochemical impedance spectroscopy 3,17 and salt spray testing 19 which are generally performed in environments and with inhibitor concentrations that are not directly comparable.…”

“…15,16 Although studies on the inhibition performance of each of the above mentioned compounds are abundant in the literature, comparative studies are less common. 12 Further, the techniques used for the assessment of the performance vary widely, ranging from potentiodynamic polarization 17,18 to electrochemical impedance spectroscopy 3,17 and salt spray testing 19 which are generally performed in environments and with inhibitor concentrations that are not directly comparable.…”

“…3,20 The technique is based on recording the potential and the coupling current of two nominally identical electrodes immersed in an aggressive environment in the presence and absence of the candidate corrosion inhibitor. Simultaneously, images of the surface are acquired at a fixed time interval, revealing the progress of corrosion on the surface.…”