Adaptability investigations on bottom modified blade in powder spreading process of additive manufacturing

Abstract Powder spreading in powder-bed-based fusion additive manufacturing has been regarded as one of the most fundamental steps in the fabrication of high-performance components. Modified blade geometry would promote a more desirable particle motion state during spreading that would improve the quality of the spread powder bed. In this work, the vertical blade has been modified into the intact-arc blade and the new designed half-arc blade, then packing properties of powder beds from these blades under a wide range of operation parameters have been investigated to reveal their adaptations to powder spreading. Results indicate that particle deposition behavior from powder pile to powder layer has been improved after introducing the arc-bottom part into the blade when considering all operation parameters. Particularly, the packing property from the newly designed half-arc blade shows the most significant improvement. Mechanism analysis demonstrates that the introduced half-arc-bottom part can weaken the effect of the strong force chain in front of the blade compared to the straight bottom vertical blade. Moreover, the straight-bottom part behind the arc-bottom part in the half-arc blade would maintain the compacted state of particles and gradually remove the local load rather than release it into the particle motion. Therefore, the newly designed half-arc blade has revealed the most prominent operation region compared with the other blades, especially under operation parameters of low gap height or high blade velocity, which would preferably satisfy efficient powder spreading demand in practical additive manufacturing process.