Extrusion-based additive manufacturing of ZrO2 using photoinitiated polymerization

Thanks to the exceptional combination of mechanical, thermal, chemical and biological properties, engineering ceramics are becoming increasingly important in the nowadays-industrial landscape. Traditionally, ceramic components are produced via near net-shape techniques, involving labor and expensive processing routes that use molds or dies such as injection molding, green machining, firing, sintering and finish machining. Hence, traditional ceramic manufacturing technologies lack the ability to compete in a customized and small series market, as it exists for e.g. aerospace and biomedical applications. The fabrication of miniature and complex parts as well as small features is also a limitation. In this context, Additive Manufacturing provides an important contribution, given the large design freedom and decoupling of production cost and complexity. Especially, nozzle based techniques offer new opportunities thanks to the efficient usage of material and economical advantage in prototyping and single/small series component production. In this work, a novel processing route for the production of AM ceramics components is proposed. It combines the advantages of AM syringe extrusion and UV curing into a single 3D printing technique, along with the potential for multi-material, complex and miniature ceramic component production. Different dispersions of ZrO2 and commercially available UV resins (containing from 22.5 to 55 vol.% ZrO2) are prepared using two different mixing techniques. The homogeneity, rheology and printability of those dispersions are subsequently investigated, along with firing and sintering trials. A sample density of about 92.1% has been obtained after sintering, proving the potential of the technology in development. A novel methodology for the process assessment is also proposed.