Corrosion process of Mg–Sn alloys revealed via in situ synchrotron X-ray radiography

Abstract

Corrosion process of Mg–Sn alloys is investigated via in situ synchrotron X-ray radiography, and corrosion rates are compared under potentiostatic and static immersion conditions. The occurrence and extension of corrosion pits are directly observed. The fine grains and higher volume of Mg2Sn in Mg–9Sn alloy reduce the anodic current density at −1.5 V potentiostatic polarization. However, the peeling of Mg2Sn phases off the alloy matrix increases the corrosion, and the corrosion rate of Mg–Sn alloys depends on the cathodic reaction rather than anodic current density in static immersion condition.