Evaluation of Tannins as Potential Green Corrosion Inhibitors of Aluminium Alloy Used in Aeronautical Industry

Abstract

In this work some organic natural products were studied, namely tannic acid, gallic acid, mimosa tannin and chestnut tannin, as potential green corrosion inhibitors of the aluminium alloy AA2024-T3. The anodizing treatment was performed in a solution of the referred organic compounds in diluted sulfuric acid. The electrochemical impedance spectroscopy and the potentiodynamic polarization were performed to assess sealing quality and corrosion protection granted by the anodic films. To understand the green inhibitors; interaction with the metal surface, FTIR spectra of anodizing and anodizing and sealed samples of AA2023-T3 were recorded, and the shifts in the position of the major bands confirmed that the green inhibitor interacts with the metal surface. Images of the morphology of the coatings were provided by Scanning Electron Microscopy. From the results obtained through the various techniques that were used to carry out this study it is possible to conclude that the formed anodic films can be a good contribution for the prevention of corrosion in the aluminium alloy AA2024-T3.

Experimental and theoretical investigations of new Schiff base compound adsorption on aluminium in 1 M HCl

“…IR (KBr, cm -1 ): 1638 (ʋ C=N Schiff base), 1490 ( C=C), 3365 ( OH). 1 The chemical structure of the prepared Schiff base is shown in Figure 1. Autolab instrument was used to perform polarization tests.…”

“…Corrosion of aluminium is a common process [1]. Aluminium is an active metal, but its corrosion resistance is high in most situations due to the production of aluminium oxide layer on its surface [2,3].…”

“…At present, several organic chemicals are commonly utilized in industry to reduce corrosion and manage alkaline and acidic environmental conditions [16][17][18][19][20][21]. Up to now, many organic compounds have been used to prevent aluminium corrosion in acidic solutions [1,[3][4][5].…”

Progress of research on gallic acid in corrosion inhibition and rust removal protection of metals

“…First, gallic acid can physically block the contact of corrosives such as water and oxygen to metal surfaces by forming a protective film (Proenca et al , 2022). The formation of protective films is attributed, on the one hand, to the interaction of gallic acid with metal ions or active sites on the surface by adsorption.…”

“…Metal products such as oil and gas pipelines and chemical storage tanks often carry highly corrosive media and/or store hazardous substances, and these structures are susceptible to corrosion and damage (Proenca et al , 2022). Severe corrosion can cause leakage of the contents, and the escape of hazardous substances into the environment can be a significant public and biological health hazard (Allély et al , 2014).…”