An intermittent anodic polarization approach for in situ event-resolved analysis of microstructure-sensitive localized corrosion initiation in an extruded Mg89Zn4Y7 alloy

An intermittent anodic polarization (IAP) approach is proposed for in situ, event-resolved analysis of localized corrosion initiation on a mesoscale surface. By interrupting polarization immediately after stable pit initiation, sustained pit growth is suppressed, enabling subsequent events and their pitting potentials to be sequentially resolved. Using an extruded Mg 89 Zn 4 Y 7 alloy, successive events exhibiting pronounced site-to-site variations in pitting potential were directly correlated with initial microstructural features. Y-rich inclusions within the LPSO phase and α-Mg adjacent to the LPSO phase were identified as representative susceptible sites. IAP thus enables event-specific analysis of microstructure–corrosion relationships without spatially isolating the surrounding microstructure.