Metal Additive Manufacturing Conference - MAMC 2020

Moisture is often regarded as one of the main reasons for poor processability of powders using L-PBF processes. To determine the influence of moisture on the spreadability a superalloy powder IN718 commonly used for SLM has been conditioned in two different states: once in the as-received and dry condition and once in a moist condition achieving by storing the powder four weeks in an atmosphere containing a relative humidity of 75 %. Using a self built machine and a subsequent analysis method specially developed for testing the spreadability of a powder, the differently conditioned IN718 powder batches have been investigated regarding the surface roughness and flatness of the powder layers. Additionally, the formation of empty spots between the powder particles in the first layer has been studied.