Asymptotic pathways to carbon minimization in laser powder bed fusion

Laser powder bed fusion of metals (PBF-LB/M) is increasingly recognised as a pivotal technology to drive the green transition in manufacturing. While its high material efficiency and minimised resource usage offer sustainability benefits, the energy-intensive nature of the process poses a major environmental challenge. This study explores potential avenues to asymptotically reduce the carbon footprint of the PBF-LB/M process through a multifaceted approach, to realise its full potential as a sustainable manufacturing process. A cradle-to-gate scope is used to identify the key drivers of environmental impact and propose a structured sequence of targeted optimisations of the operating conditions, each quantified using a life cycle approach. Key strategies to reduce environmental impact—including switching to renewable energy, using lower impact gases such as nitrogen, increasing recycled content, on-site nitrogen generation and optimising component design—are progressively implemented and their cumulative impact is quantitatively assessed within the GHG Protocol. The paper provides a clear roadmap through a sequence of scenarios for sustainable PBF-LB/M, to meet the requirements of responsible manufacturing.