Influence of the atomization medium on the properties of stainless steel SLM parts

The importance of powders on the final part properties in selective laser melting (SLM) process is well-known. At the moment, gas atomization is used to produce powders for the SLM process. However, there is a growing interest in investigating the use of the less expensive water atomization process. In this work, water and gas atomized powders were used as feedstock to produce specimens with an industrial SLM system. First, the influence of particle size distribution and layer thickness on the final part density was studied by varying process parameters by means of a factorial design. The results showed that by using a particle size distribution in the range 15–60 μm the difference in part density between water and gas atomized is negligible even using the same combination of parameters. The tensile properties of GA and WA powder are comparable: respectively 599 and 601 MPa for the ultimate tensile strength, 18% and 20% for the elongation.