Recent advancements in metal additive manufacturing have made this technology a compelling solution for the production of industrial parts. For example, Wire Arc Additive Manufacturing (WAAM) shows great promise for producing large stainless steel components with medium to high geometric complexity. WAAM has been demonstrated to achieve mechanical properties and near-net-shape manufacturing characteristics similar to those obtained with green sand casting, a widely utilized process in large parts applications. In the current context, it is relevant to assess and compare the environmental performance of the two processes, in order to determine whether WAAM can represent a more sustainable alternative. This paper aims to undertake a cradle-to-gate life cycle assessment (LCA) for the fabrication of a single component using WAAM and green sand casting. To facilitate comparison, the following proposal is made: a common generic decomposition of manufacturing phases is to be adopted, with all flows and stages considered for the LCA detailed in accordance with this decomposition. The associated life cycle inventory was complied with the help of experts in both processes, using data from the Ecoinvent database and experimental surveys. A representative case study of the intended application has been defined, and the EF 3.1 method has been used for the LCA. The study explores three manufacturing scenarios: first, the reference scenario in which the component is made using green sand casting; second, the same geometry produced using WAAM; and third, a mass-optimized geometry designed for WAAM. This study also demonstrates the advantage of a design-for-additive-manufacturing approach in reducing the environmental impact of WAAM-produced compared to those produced by green sand casting.
Balidas et al. (2026) studied this question.