Powder deposition mechanism during powder spreading with different spreader geometries in powder bed fusion additive manufacturing

Discrete element method is used in this work to examine the mechanisms determining powder deposition effi-ciency during powder spreading in powder bed fusion additive manufacturing. The results reveal that powder flow in the powder pile is critical for the formation and break of transient jamming. The forces on the underlying part increase first with spreading speed then decrease with a large fluctuation. For varied spreader shapes, a small inclined angle of the spreader surface makes the force barrier farther from the discharging gap, creating a larger region which ensure enough powder supply to the gap. Furthermore, a small inclined angle of the spreader sur -face close to the gap results in less particle motion conflicts at the gap and ensures larger discharging rate through the gap. This mechanism explains why spreaders with inclined or round surfaces help increase powder deposi-tion efficiency. (c) 2021 Elsevier B.V. All rights reserved.

Automated summary

The study utilized the discrete element method to investigate the mechanisms affecting powder deposition efficiency during powder spreading in powder bed fusion additive manufacturing. It was found that factors such as powder flow, transient jamming, forces on the underlying part, and spreader shape all play a crucial role in determining the efficiency of powder deposition.