Influence of Arc Voltage and Travel Speed on the Environmental Footprint of WAAM: An Experimental LCA Approach

This study presents a cradle-to-gate Life Cycle Assessment (LCA) of the Wire Arc Additive Manufacturing (WAAM) process using the gas metal arc welding (GMAW) method for ER70S-6 steel deposition. Two deposition strategies, high-voltage high-speed (HVHS) and low-voltage low-speed (LVLS), were experimentally implemented to explore the environmental implications of adjusting the arc voltage and travel speed. Experimental measurements of electrical energy consumption were obtained using a JAM-300 power analyzer, while wall geometry (height and minimum width) was evaluated through ImageJ analysis to define the functional unit of a 15-layer wall. The environmental modeling was performed in SimaPro using the Ecoinvent v3 database and the EPD2018 impact method, complemented by endpoint aggregation through the ReCiPe 2016 (Hierarchist) approach. The results reveal that increasing the arc voltage while reducing the deposition time marginally elevates total environmental burdens. The global warming potential (GWP) of the HVHS strategy (0.746 kg CO₂-eq) was only 0.94% higher than LVLS (0.739 kg CO₂-eq), while total endpoint impacts were approximately 10.6% greater for HVHS. This increase is attributed to the higher instantaneous power demand, which outweighs the shorter process duration. Overall, process optimization in WAAM must balance energy efficiency with productivity, as increasing voltage does not necessarily reduce environmental impact. The findings provide valuable insights into the influence of electrical parameters on the sustainability of WAAM.