Metal Additive Manufacturing Conference 2019

Despite the advantages in terms of geometrical freedom or lightweight design, the use of L-PBF is often limited by economic constraints or currently achievable part costs, respectively. With an expected increase of L-PBF machine productivity during the next years, an increase of the share of material costs and the share of non-productive time for powder layer application process is to be expeted. This results in a demand for less expensive powder materials and advanced processing strategies for the short-and medium-term advancement of L-PBF. As one possible approach, the processing of gas- and water atomized stainless steel (316L) powders with different morphology and particle size distribution as well as their impact on L-PBF productivity is investigated. The actual powder applicability in L-PBF systems and the L-PBF processability determines the minimum necessary powder quality. The main focus of the presented work is put on the interaction between powder quality, part quality and cost-effectiveness of the L-PBF process. To this end, the influence of the gas and water-atomized powder properties (particle size and morphology) during the powder layer application process at highest possible powder recoating speeds and the resulting powder bed properties (powder layer density, powder bed density, powder segregation) and part properties (part density, surface roughness and tensile strength) is investigated.