Revealing filler morphology in 3D-printed thermoset nanocomposites by scanning microbeam X-ray scattering

Room temperature direct-ink-write printing of epoxy-nanoclay-carbon fiber composites produces parts with high stiffness and strength. Establishing clear relationships between print parameters, filler orientation, properties is difficult, in part owing to challenges characterization. Here, we perform scanning microbeam X-ray scattering 5 micrometer spatial resolution on cross-sections printed (a) epoxy-nanoclay composite (b) reinforced composite. The nanoclay morphology directly visualized, illuminating the road geometry far greater clarity than other techniques. Near boundary each road, platelets are preferentially oriented coplanar boundary. Shear alignment within nozzle during extrusion, road-to-road shear upon deposition two proposed factors leading this orientation. In sample containing carbon fiber, wide angle diffraction enables mapping visualization fibers onto geometry. does not significantly affect morphology. Finally, from small map, qualitatively reproduce a polarized optical microscope image, revealing that microscopy capable visualizing large-scale structure these systems.