Reducing the corrosion rate of magnesium alloys using ethylene glycol for advanced electrochemical imaging

Highlights: • Corrosion of AM50 was slowed in ethylene glycol solution compared with aqueous. • Water additions to ethylene glycol accelerated corrosion, enabling access to water as an oxidant. • Ethylene glycol exposure lowers corrosion activity at alloy surface enabling application of SECM. • Ferrocenemethanol (a redox active species) was successful in mapping areas of high anodic activity. - Abstract: The corrosion of an AM50 Mg alloy was studied in ethylene glycol using electrochemical and electron microscopy techniques. Switching from H₂O to ethylene glycol, it was shown that the corrosion of the AM50 alloy was significantly suppressed thereby slowing H₂ evolution. The corrosion of the AM50 alloy was mapped using scanning electrochemical microscopy in the feedback mode. Ferrocenemethanol can be used to expose the reactive anodic areas on the Mg alloy. These studies confirmed that studies in ethylene glycol can be used to elucidate reaction features obscured by rapid corrosion in H₂O without significantly altering the mechanism and damage morphology