Evaluation of Mycocorrosion by Amorphotheca resinae in Aluminum Alloys 2024, 7075, 5083 and 3105: A Comprehensive Study

Abstract

Amorphotheca resinae is a fungus that particularly corrodes aeronautical aluminum alloys, leading to economic issues in various industries. This study aims to investigate the effects of this fungus on the corrosion of four different aluminum alloys, namely 2024, 7075, 5083, and 3105, after 25, 50, and 75 days through scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM), 3D profilometry, weight loss (%) measurement, energy dispersive spectrometry (EDS), electrochemical impedance (EIS), and pH changes. After 25 days, the 2024 alloy had the highest mycocorrosion rate (1.3417 mpy), while alloy 3105 had an undetectable value on this day. According to the EIS test, the 3105 alloy had the highest level of resistance (1.12×105 Ω.cm²) to corrosion, while the 2024 alloy was the most susceptible (7138 Ω.cm²). The qualitative data from SEM, CLSM, and 3D profilometry also confirmed the quantitative findings where the surface pits on the 2024 alloy were deeper than those of other alloys. Overall, the results showed that the lowest and highest corrosion rates mediated by A. resinae belonged to 3105 and 2024 alloys, respectively. These findings could have significant implications for industries that use aluminum alloys and might help in developing strategies to prevent or control biocorrosion.