Binder jetting process effects on metal powder reusability

Due to its high cost and its direct impact in final part properties, the reuse of metal powders for additive manufacturing purposes is being a trending subject of study. In order to reduce production costs, ensure a robust process quality management, and consolidate a widespread industry adoption of Additive Manufacturing (AM) technology, the analysis and control of the effect that multiple process cycles have on powder raw material is crucial. To this aim, a starting virgin 316L powder was subjected to a number of Binder Jet printing and curing cycles, simulating large size production lots. The powder particle size distribution, oxide content and powder contamination was analysed along with the sinterability of some control specimens printed between certain number of process cycles. Results showed that, unlike in other powder bed based AM technologies, the reuse of powder material in Binder Jetting process has a minimum influence on raw powder and final part density.