Ceramic On-Demand Extrusion (CODE) is an extrusion-based additive manufacturing process recently developed for fabricating dense, functional ceramic components. This paper presents a further development of this process and focuses on fabricating 3 mol% yttria-stabilized zirconia (3YSZ) components that cannot be fabricated without using support structures. The 3YSZ paste is deposited through the main nozzle, and a polycaprolactone (PCL) pellet feedstock is melted and deposited through an auxiliary nozzle to build support structures. After a green part is printed and dried, the support structures are removed by heating the part to ~70°C to melt the PCL. The part is then sintered at 1550°C to achieve near theoretical density. The maximum angle of overhanging feature that can be fabricated without support was determined to be 60°. Sample parts were fabricated and evaluated to demonstrate the effectiveness of the PCL support material and CODE’s capability to fabricate geometrically complex parts.
Wenbin Li, Amir Ghazanfari, Devin McMillen, Andrew Scherff, Ming Leu, and Gregory Hilmas. "Fabricating Zirconia Parts with Organic Support Material by the Ceramic On-Demand Extrusion Process" Solid Freeform Fabrication 2017: Proceedings of the 28th Annual International Solid Freeform Fabrication Symposium – An Additive Manufacturing Conference (2017): 605-615.