Impact of Powder Characteristics on the Microstructure - Property Relationships of PBF-LB Metallic Alloys

The present work was carried out as part of the French CaracPow project which is dedicated to a better understanding of the characteristics of metal powders used in the PBF-LB process for the purpose of a better consistency in mechanical properties. In this investigation, the effects of variability between powder batches as well as long-term stability are determined in terms of chemical, physical, rheological and mechanical properties for the 316L stainless steel and for IN625 alloys. Measurements of powder size distribution (PSD), sphericity, presence of satellites, tapped density and flowability were made for different powder batches. A uniform spreading of powder layers and an improved repeatability over time for PBF-LB are key factors for build-to-build consistency. This work has been performed within the framework of the French Additive Factory Hub (AFH) bringing together several research institutes and industrial end-users.