Prospective life cycle assessment of future Wire Arc Additive Manufacturing deposition process for large-scale steel parts

Wire Arc Additive Manufacturing (WAAM) is a promising approach for the sustainable production of large-scale metal components. This study presents the first prospective Life Cycle Assessment (LCA) focused on the gate-to-gate manufacturing stage of seven patented, currently immature WAAM technologies. These technologies are projected to reach industrial maturity by 2035 and are evaluated in both laboratory-scale and anticipated industrial-scale configurations. Key findings reveal that future WAAM systems may reduce environmental impacts by an average of 45 % at the lab-scale and 74 % at the industrial scale compared to current WAAM. Argon shielding gas consistently contributes to more than 70 % of the total environmental impact. Plasma-based future WAAM significantly outperforms electric arc variants, exhibiting at least 20 % lower environmental impact than current WAAM systems. Multi-axis WAAM also demonstrates environmental advantages, with a 21 % lower impact compared to planar setups at the lab scale. These sustainability improvements, which remain consistent across various future scenarios, highlight promising pathways for improving WAAM technologies, particularly favouring plasma-based and multi-axis systems for large-scale applications.