Novel composite filament usable in low-cost 3D printers for fabrication of complex ceramic shapes

Abstract Fused filament fabrication of ceramic (FFFC) is a promising additive manufacturing (AM) method for production of complex-shaped ceramic bodies. It allows to generate complex structures hardly obtainable by conventional ceramic shaping methods. The thermal processing of ceramic composite objects prepared by the FFFC generates structures with the option to fine-tune the external size of objects after processing by changing the thermal processing temperatures. Higher temperatures lead to higher shrinkage, while maintaining the complex internal structure generated in 3D printing process. Previously published studies concerning ceramic composite filaments often mention requirement of special modification to AM devices such as pre-heating of the feedstock before its entry point into the feeder to avoid mechanical damage. This study investigates internal structure of bodies prepared by FFFC using novel composite filament based on mullite ceramic and the deformation induced by processing of the composite material in the thermal processing stage. Studied in-house developed material is printable using commercial AM devices with no additional modifications of the machines and exhibits no deformations during debinding and sintering, even when using aggressive thermal debinding strategy. The material can be printed using standard 0.4 mm nozzles and does not require use of specialized high temperature furnaces. This qualifies this new composite filament as suitable material for commercial widespread application of FFFC process.