Influence of the particle size distribution on surface quality of Maraging 300 parts produced by Laser Powder Bed Fusion

Abstract

This work investigates the effect of the powder particle size distribution on the surface finish of Maraging 300 specimens, produced by the Laser Powder Bed Fusion (LPBF) process. Although it is recognized that the initial powder morphological characteristics play an important role on LPBF part density, mechanical properties and surface quality, there is a lack of empirical data that could help to link the powder properties to actual metrological established surface parameters, like Ra or Sa. For this reason, an extensive initial powder characterization is presented in this paper, for three Maraging 300 batches, and first insights on the different obtained LPBF surface quality are disclosed. The results demonstrate how small differences in particle size distribution can decrease the LPBF surface roughness consistently. Moreover, it is shown how the use of fine powder can unlock novel LPBF processing strategies to further improve surface finish, down to 1.5 µm measured Ra, and thus reduce eventual post-processing efforts.status: publishe