Numerical study of texture in material extrusion: Orientation in a multicomponent system of spheres and ellipsoids

Extrusion-based Additive Manufacturing techniques, such as Robocasting, produce continuous filaments to create layer-wise structures. The material properties of these structures depend on the orientation of suspended particles within the filament. This orientation can be predicted by analytical models, but those models do not exist for the paste specifically regarded in this work: A multicomponent paste that consists of two types of particles having either spherical and ellipsoidal shape, respectively. To improve understanding of the texture evolution within such a suspension, we use experimentally validated particle-level simulations to address the following three questions: First, how strong do the spheres affect the alignment of ellipsoids under various deformations in terms of shear and/or elongation? Second, to which extend does an analytical orientation prediction model match the numerical simulations although the model ignores the presence of spheres? Third, which means exist to improve alignment of the ellipsoids in such a multicomponent system?