Utilization of large scale infrastructures to study the effect of the processing gas in Laser Powder Bed Fusion

Research Project, 2020

Purpose and goal: The project aims to increase the understanding of the effect of the process gas during Laser Powder Bed Fusion (LPBF) on microstructure development and resulting properties. Processing gases in LPBF are normally limited to nitrogen and argon, whereas use of gases with high conductivity as helium is believed to allow further increase in productivity for LPBF process and result in finer microstructures. The scope is thus to study in-situ the effect of He-gas and its mixes on the LPBF process. The project is driven by industrial interest of Linde Gas AB.
Expected results and effects: Results of the project will improve understanding of the effect of the He and its mixtures on LPBF process and component properties. This will allow tailored He-containing gas mixtures and further enable their future integration into industrial LPBF processing. This will enable significant boost of LPBF production speed by about 40% without compromising the component properties. Approach and implementation: The microstructure development during LPBF processing will be studied in-situ using synchrotron X-ray diffraction using a unique L-PBF setup developed at the Paul Scherrer Institute and the measurement will be conducted at the MicroXAS and MS beamlines at the Swiss Light Source. The residual stresses, determined by the material thermal history, will be further studied by high energy X-ray diffraction using the X-ray CoreLab at the Helmoltz Zentrum Berlin (HZB).