Wire arc directed energy deposition of AZ61 magnesium alloy fabricated using cold metal transfer

Abstract

This research investigates the challenges and potential of Cold Metal Transfer (CMT) for Wire-Arc Additive Manufacturing (WAAM, also known as WADED – Wire-Arc Directed Energy Deposition) of AZ61 magnesium alloys. Despite the excellent properties of magnesium alloys, their processing is challenging due to high vapour pressure, low boiling point, flammability, and difficulties in maintaining a stable welding process. This study examines the effects of key CMT parameters, including boost phase current and duration, burn phase current, electrode speed, and short-circuit (SC) phase current. The results demonstrate that boost phase current, cycle time, droplet surface tension, and material consumption significantly influence deposition size and shape. By optimising these parameters, a stable and efficient welding process was achieved, improving contact angle and ensuring sufficient penetration. The optimised conditions enabled the fabrication of a 50-layer thin-walled component, highlighting the study’s contribution to advancing CMT applications in WADED processes.