Wire arc additive manufacturing (WAAM) enables the production of structural components with topologically optimised geometries thus leading to significant self-weight reductions for a given load-carrying capacity. A common question arises regarding the environmental performance of WAAM structural components in comparison with conventional steel structural components. Thus, a comparative cradle-to-gate life cycle assessment has been conducted where the environmental impact of producing a topologically optimised WAAM steel beam is compared with that of producing a conventional hot-rolled steel I-beam. The beams are 2 m long, simply-supported and loaded vertically at midspan. The impact of using either carbon steel or stainless steel is investigated. The results demonstrate that the carbon steel and stainless steel WAAM beams have 7% and 24%, respectively, lower climate change impact than the corresponding I-beams. It is concluded that WAAM can lead to lower CO₂-eq. emissions than conventional hot-rolling, provided that mass reductions of the order of 50% (which are readily attainable) can be achieved by employing WAAM in conjunction with, for instance, topology optimisation. Furthermore, it is shown that the shielding gas contributes greatly to the environmental impact of WAAM, and that, by using higher deposition rates or by utilising renewable energy sources, the impact of WAAM can be reduced by more than 30%.

电弧增材制造 (WAAM) 可以生产具有拓扑优化几何形状的结构部件，从而在给定的承载能力下显着减轻自重。与传统钢结构部件相比，WAAM 结构部件的环境性能出现了一个常见问题。因此，进行了从摇篮到大门的比较生命周期评估，将生产拓扑优化的 WAAM 钢梁与生产传统热轧钢工字梁的环境影响进行了比较。梁长2m，跨中简支竖向受载。研究了使用碳钢或不锈钢的影响。结果表明，碳钢和不锈钢 WAAM 梁有 7% 和 24%，分别比相应的工字梁更低的气候变化影响。结论是 WAAM 可以降低 CO₂ -当量。排放量低于传统热轧，前提是通过结合使用 WAAM 和拓扑优化等方法可以实现质量减少 50%（这很容易实现）。此外，表明保护气体对 WAAM 的环境影响有很大贡献，并且通过使用更高的沉积速率或利用可再生能源，WAAM 的影响可以减少 30% 以上。