3D Printed Ceramics: Current Challenges and Future Potential

Abstract

Materials and processes for additive layer manufacture have advanced considerably in the last few years and have moved the application of the technology away from prototyping to fabrication and manufacture. One area that still has little effective presence is that of 3D printed ceramics. Ceramic materials have proved difficult to integrate with 3D printing technologies and there is still a considerable way to go before the characteristics of most of these materials can be considered adequate. The problems experienced are high firing contractions, low density and strength and potential incompatibility with glazes. For general tableware and giftware ceramics giftware ceramics two main methods of 3D printing are used, paste extrusion through a syringe and fine nozzle and a powder binder system that ink jets binder onto a powder bed containing a mix of ceramic powder and an organic binder. The paste extrusion system has the advantage that conventional ceramic pastes and bodies can be used but the layer thickness is coarse and there can be problems with maintaining an even extrusion of a thin bead, the main issue with this method however is the restriction on geometric freedom that cannot compete with other 3D printing methods. The powder/binder process gives the ability to form complex shapes, but has an inherent high porosity due to the burn out of organic binders and the restriction on particle size range required for the process to function correctly. The manufacture of high performance monolithic ceramics such as alumina and zirconia is achieved by using photo cure resins with a high loading of ceramic material, this requires a thermal debonding process that results in a very high firing shrinkage that can affect the dimensional stability in the firing/sintering. The reasons for wanting to use ceramic materials are to utilise their unique properties but the limitations of the available processes make these properties difficult to realise by current additive manufacturing methods. This paper will review and compare contemporary ceramic additive manufacturing processes and explain why the above issues exist and what potential solutions may be available. 2 The Centre for Fine Print Research at the University of the West of England in Bristol has a history of over eight years research into 3D printed ceramics and has developed and patented materials and processes in this area, and has collaborated with leading ceramic manufacturers and material suppliers in the U.K. to improve and refine the process. Our ongoing research into this area is exploring potential solutions to these issues including hybrid extrusion/machining for paste extrusion ceramics, colloidal infiltration of preformed powder/binder 3D printed and novel methods of pre-processing the ceramic powders used in powder/binder 3D printing to increase the density and fired performance of the ceramic material.