Influence of Nanoparticle Coating on Flow Behavior of 316L Stainless Steel Powder in Powder-based Additive Manufacturing

Conference Abstract: In powder-bed-based additive manufacturing (AM) processes, the flowability of the powder is decisive for the quality of the manufactured part. Since fine particle fractions worsen the flowability, in the laser powder bed fusion (LPBF) process the lower limit of the powder fraction is usually 15 μm. Nanoparticle coatings can reduce the cohesive forces between particles. It has been investigated how the fumed silica (SiO2) nanoparticle coating affect the initial flow behavior of standard gas-atomized (15-45 μm) 316L powder and powders with modified particle size distribution (0-45 μm, 15-63 μm, 0-63 μm). It was demonstrated that flowability and bulk density increased as a result of the coating. Relative density and mechanical properties of the LPBF specimen showed similar results compared to the un-coated powder with increased tensile strength. The economic potential of coated powder for AM was demonstrated by the successful LPBF processing of fractions 15-45 μm and 0-63 μm.