EXTRUSION-BASED ADDITIVE MANUFACTURING OF POLYMER-DERIVED CERAMIC COMPOSITES

摘要

Extrusion-based additive manufacturing (AM) technologies - including fused filament fabrication (FFF) and direct ink writing (DIW) - present opportunities to create composite materials and multi-material architectures that cannot be made using other AM technologies. The direct deposition nature of these processes enable the straightforward deposition of multiple materials though the use of multiple print heads, while the extrusion process aligns high aspect ratio filler materials like fibers, whiskers, and platelets. This alignment, coupled with the flexibility to choose the print path for each layer provides the ability to prescribe unique fiber arrangements within printed parts that simply does not exist with other manufacturing technologies. This talk will focus on recent developments in DIW of polysilazane-based preceramic polymer formulations and the resulting ceramic composites. Special focus will be paid to the rheological requirements for successful printing, as well as the relationship between filler morphology, ink rheology, print parameters (i.e. nozzle size and print speed), and anisotropy in the printed part. Insights gained from recent studies on printed epoxy composites will be discussed in the context of ceramic composites. Finally, novel deposition strategies to control fiber orientation and create novel multi-material architectures will also be discussed. Current challenges and open questions will be highlighted throughout the talk.