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.