Water and gas atomized AISI 316 L applied in DED-LB/M: influence of powder properties on mechanical properties

Powder properties are considered a key factor in mechanical properties in laser additive manufacturing, although few studies have investigated the effects in laser beam directed energy deposition for metal materials (DED-LB/M). Water atomized (WA), and gas atomized (GA) powders are frequently used but may result in different part properties due to powder properties. To examine their qualification for DED-LB/M, this work examines powders and mechanical properties of AISI 316 L. Also, examination techniques are compared. The results show that the powder production has no relevant influence on porosity and Archimedian density of built parts. WA powders show good processability in the process, despite unfavorable morphology. In contrast, WA specimen reach only 10% fracture elongation in tensile testing whereas GA-based specimen achieve 30%. Tensile strength of both is above 500 MPa. The reason for the lower mechanical property values can be attributed to defects and oxides. Yet WA powders may provide a cost-effective alternative for DED-LB/M when a reduced fracture elongation is acceptable.