Spreading and Packing of Alumina Powder Using a Displacement-controlled Roller in SLFS

Selective laser flash sintering (SLFS) is a powder bed fusion process that enables direct additive manufacturing of ceramics. Similar to other powder bed fusion processes, the density of the ceramic powder bed impacts attainable density of the final part. Experiments were conducted using a spray-dried alumina powder that was spread and then packed using a displacementlimited roller. The spreadability of the powder was visually assessed. The microstructure of the resulting compacted powder was compared to a traditional method of pressing ceramic powder into a pellet using a die and hydraulic press. Packed regions were sintered to final density and compared in a scanning electron microscope to samples hydraulically pressed at known pressure to evaluate the efficacy of a roller-based packing process.