Combining simulated immersion and statistical analysis to reveal microbial evidence of corrosion failure in fuel aluminium alloy.

Microbial contamination has caused engineering problems such as fuel deterioration, corrosion of maritime aviation aluminium alloy, and fuel tank leakage. By integrating metagenomic analysis of a fuel corrosion biofilm and microbial cultivation techniques, we selected ten types of microbial resources that might affect the deteriorated corrosion of aluminium alloy in aviation fuel for corrosion immersion simulation experiments. Through multidimensional analysis of corrosive microorganisms, medium environment, and material surfaces, the qualitative and quantitative microbial evidence for the failure of aluminium alloy in aviation fuel tanks was presented. The statistical analysis results indicated that anaerobic microorganisms exhibited a higher corrosiveness towards the 2024 T3 aluminium alloy than aerobic microorganisms. The corrosion extent of microorganisms was significantly influenced by the types of microorganisms present, as evidenced by the presence of potential corrosion-inhibiting microorganisms within the biofilm. In mixed microbial contamination, aerobic microorganisms accelerated fuel degradation and rust formation. In contrast, anaerobic microorganisms, particularly co-culture systems of Desulfovibrio bizertensis and Methanosarcine barkeri accelerated the pitting of aluminium alloy. The galvanic electrochemical effect was considered to be an important indicator for characterizing the corrosion of aluminium materials in fuel-water systems.