(437g) Material Selection and Formulation for Material Extrusion Additive Manufacturing

Additive manufacturing (AM) has drawn interest from fields ranging from aerospace to regenerative medicine to metamaterials. Using AM, specimens with complex internal geometries and structures can be manufactured. Despite the advantages and interest, broader use of AM is limited by poor mechanical properties, lack of reliability, and lack of expertise. We use experimental and computational approaches to better understand the underlying phenomena that control material extrusion (MatEx) AM. A simulation was developed that describes temperature throughout a build. At benchtop (FFF) scales, short times over T_g were reported, indicating limited opportunity for interlayer diffusion. At larger (BAAM) scales, much longer times above T_g were observed, which can lead to continued flow of extruded material and warping of the printed structure. The effects of material and processing parameters were investigated at both scales, and different trends were observed at the small and large scales. These results help explain experimental observations and provide guidance for material development at all scales of MatEx.