Evaluation of corrosion characteristics of aluminum alloys in the bio-ethanol gasoline blended fuel by 2-electrode electrochemical impedance spectroscopy

The corrosion characteristics of aluminum alloys were investigated in the bio-ethanol gasoline blended fuel at 100 °C. The corrosion property of aluminum alloys was evaluated by an in situ 2-electrode electrochemical impedance spectroscopy (EIS), weight loss test and pressure–time measurement. Surface analysis was carried out after immersion test. The polarization resistance of aluminum alloys was increased at initial immersion time due to the formation of boehemite film (γ-AlOOH); after that, it was decreased due to the initiation of aluminum alkoxide reaction. The pressure of autoclave was increased because of the hydrogen gas from the aluminum–ethanol alkoxide reaction. It was verified that a 2-electrode EIS and pressure–time measurements were able to evaluate the corrosion resistance of aluminum alloys in the bio-ethanol gasoline blended solution.