| Abstract Scope |
In powder bed additive manufacturing (AM), powder spreading process often leads to inhomogeneity in layer height, porosity level, and particle size distribution. Hence, the creating of homogeneous layers is the first task for optimal printing. The conventional assessment methods for powder bed quality are limited to a measurement of powder morphology, flowability, particle size distribution, surface roughness, and packing density. However, those techniques may not be the most appropriate to quantify the bed characteristics since it is not able to capture local particle configuration and does not provide any vectoral information (e.g., arrangement of contacts between particles during spreading). In this study, 1) discrete element method (DEM) model was developed for multiple-layer powder spreading process, 2) powder spreading dynamics including angle of repose (AOR) was measured using high-speed camera, 3) the effect of particle spreading dynamics on spatial powder bed structure and quality were investigated using scalar and tensorial methods. |