Life Cycle Assessment of Additive Metal Manufacturing vs. Conventional Manufacturing: A Case Study on a 316L Stainless Steel Part

Resource and energy efficiency remain key challenges in environmentally sustainable manufacturing. Additive manufacturing (AM), particularly laser powder bed fusion (PBF-LB), offers greater design freedom than conventional manufacturing (CM), enabling complex geometries and bionic lightweight structures. However, AM's environmental benefits are uncertain due to its high energy demand. In this study, a cradle-to-gate life cycle assessment (LCA) compares a conventionally manufactured stainless steel food-filling nozzle to an additively manufactured design-optimized counterpart. The LCA follows ISO 14040 and ISO 14044. The life cycle impact assessment (LCIA) method ReCiPe 2016 midpoint (Hierarchist, H) was applied to evaluate the environmental impacts. The results show that the AM route has lower environmental impacts in 15 out of 18 categories, including a substantial 56.3% reduction in carcinogenic human toxicity. The CM route exhibited lower impacts only in ionizing radiation due to its lower energy demand. Material efficiency and energy intensity emerged as the key drivers influencing comparative outcomes in both manufacturing processes.