Microstructure and corrosion behaviour of wire arc additive manufactured AA2024 alloy thin wall structure

Abstract In the present work, the microstructure and corrosion behaviour of wire arc additive manufactured (WAAM) AA2024 alloy thin wall structure are investigated. Three distinctive zones are present in the WAAM structure, including melt pool zone (MPZ), melt pool border (MPB) and heat affected zone (HAZ). Localized corrosion initiates at the multi-phase lamellar eutectic structure via de-alloying of S-phase (Al2CuMg) intermetallics. MPB is most susceptible to localized corrosion due to its relatively high volume fraction of eutectic S-phase resulted from alloying elements segregation during solidification.