Mechanistic insights into chemical corrosion of AA1050 in ethanol-blended fuels with water contamination via phase field modeling

Abstract

Aluminum alloys are widely used in automotive construction, and since the introduction of biogenic ethanol into fuels, the issue of nonaqueous alcoholate corrosion has become an important topic. In this paper, the kinetics of AA1050 temperature-induced alcoholate pitting corrosion are examined experimentally with a specially constructed microreactor. The generated data are utilized to create a phase field model for the pit growth phase. The effects of ethanol-blend composition and water content are quantitatively assessed and simulated. Phase field simulations allow for the first time the mechanistic characterization of the chemical corrosion process with a water content of up to 0.3% and an estimation of relevant reaction parameters at temperatures of up to 150°C. The approach can further be utilized to develop strategies for minimizing corrosion risk in-service.