Rheological characterisation of ceramic inks for 3D direct ink writing: A review

• Published in: Journal of the European Ceramic Society Vol. 41; no. 16; pp. 18 - 33
• Main Authors: del-Mazo-Barbara, Laura, Ginebra, Maria-Pau
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-12-2021
• Subjects: 3D printing; Direct Ink Writing; Printability; Rheology; Robocasting; Robocasting; Printability; Rheology; 3D printing; Direct Ink Writing
• ISSN: 0955-2219; 1873-619X
• DOI: 10.1016/j.jeurceramsoc.2021.08.031

•Ceramic pastes are used for microextrusion based 3D-printing, including colloidal suspensions and hydrogel or organogel based inks.•Direct ink writing imposes stringent requirements on the ink’s rheological behaviour.•As applications become more sophisticated,•inks with excellent extrudability and shape fidelity are required.•Often, the development of ink formulations has been based on trial-and-error, overlooking the rheological characterisation.•A thorough rheological characterisation is crucial fora rational design of ceramic inks with enhanced performance.
3D printing is a competitive manufacturing technology, which has opened up new possibilities for the fabrication of complex ceramic structures and customised parts. Extrusion-based technologies, also known as direct ink writing (DIW) or robocasting, are amongst the most used for ceramic materials. In them, the rheological properties of the ink play a crucial role, determining both the extrudability of the paste and the shape fidelity of the printed parts. However, comprehensive rheological studies of printable ceramic inks are scarce and may be difficult to understand for non-specialists. The aim of this review is to provide an overview of the main types of ceramic ink formulations developed for DIW and a detailed description of the more relevant rheological tests for assessing the printability of ceramic pastes. Moreover, the key rheological parameters are identified and linked to printability aspects, including the values reported in the literature for different ink compositions.