Metal powder as feedstock for laser-based additive manufacturing: From production to powder modification

Laser powder bed fusion (L-PBF) and direct laser deposition (DLD) are the two main processes currently used in the additive manufacturing (AM) of metals. For both methods, metal powders are used as feedstock, and they must present specific physical and chemical properties to ensure optimal processing and reliable and reproducible printing results. Particle morphology, size distribution, and flowability, among other factors, depend on the powder production process and directly influence the processing parameters and physical characteristics of the parts built by AM. This systematic review presents different concepts involving L-PBF and DLD manufacturing and the application of metal powders. The methods used to produce and characterize metal powders and the modification techniques to improve their processability by AM are detailed and discussed. Environmental and health risks are also presented, and safety measures that must be considered while handling metal powders. Some key topics requiring attention for further development are highlighted. Graphical abstract