Enhancing sustainability of laser-based powder bed fusion of metals through beam shaping: case study on an inconel 718 space impeller

Laser beam shaping in laser-based powder bed fusion of metals (PBF-LB/M) is a promising approach to enhance process stability, increase productivity, and enable tailored microstructures. However, its sustainability impact remains uncertain, particularly regarding energy consumption and scrap generation, as it typically involves higher laser powers. This study examines key sustainability factors in PBF-LB/M across different beam shapes and process parameters through a process-related sustainability assessment, comparing a large ring-shaped beam profile using 80 µm layer thickness to a state-of-the-art Gaussian beam profile using 40 µm layer thickness. The evaluation is based on an industrial space impeller made from Inconel 718. The analysis combines theoretical calculations with experimental measurements on a modified industrial PBF-LB/M system. Results show that the ring parameter set reduces build time by 63.0 %, energy consumption by 60.2 %, argon consumption by 57.9 %, and powder waste by 73.8 % compared to the Gaussian parameter set, while maintaining a comparable part density. The energy consumption is primarily driven by constant energy consumers (chiller, filter system), making build time the key efficiency driver, while the laser accounted for less than one-third of the total energy consumption. Surface roughness increased for the ring parameter set due to the higher layer thickness and lack of optimized contour and surface parameters. The findings on increased productivity, lowered energy consumption and improved raw material usage demonstrate the sustainability benefits of beam shaping in PBF-LB/M, encouraging future research to address trade-offs in surface quality and auxiliary energy demands through optimized process strategies.