Wire arc additive manufacturing for repairing aluminium structures in marine applications

•Aluminium alloy 4043 wall was deposited using CMT-based WAAM technology.•The microstructure in CMT+P mode revealed fine equiaxed dendrites compared to CMT.•Al-Si eutectic existed in the WAAM plates, and EDS results confirmed the same.•The corrosion rate of WAAM samples were comparable to the wrought AA5052 alloy.•WAAM is a promising technology for repairing structures in saline environments. A new approach is proposed wherein WAAM can be utilized to repair corroded surfaces in AA5052 structures. Being a marine suitable Al grade when exposed to seawater regularly, its corrosion-resistant properties decline over time. To restore the corroded surfaces, Aluminium filler material ER4043 is deposited on AA5052 using Cold metal transfer (CMT) process-based Wire arc additive manufacturing (WAAM) technology. The microstructural evolution of WAAM processed plates via CMT, and CMT + Pulse (CMT + P) modes are investigated. The microstructure of CMT + P mode revealed fine equiaxed dendrites in comparison to CMT mode. Energy Dispersive X-Ray Spectroscopy (EDS) elemental maps and line scan revealed the presence of Al-Si eutectic phase. The corrosion rate of WAAM processed samples (0.18–0.20 mm/year) was comparable with the wrought counterparts (0.19–0.21 mm/year). The industrial impact of the study is the feasibility of employing WAAM technology for repairing aluminium structures in marine environments.