Glass frit-ink development and relevant process technology for fabricating functionally graded material-structured ceramic filters via binder-jetting 3D printer

Owing to the porousness of ceramic filters, post-processing procedures, such as coating or impregnation, are applied to compensate for their low strength. However, post-processing holds thpotential for defects, including changes in porosity and delamination at the heterogeneous physical interface. This study investigated glass frit-inks and fabrication processes for ceramic filters with a functionally graded material structure to improve structural strength and effectively control stress occurring at the heterogeneous physical interface while maintaining a high porosity as a ceramic filter. A glass frit-ink was synthesized and applied to a 3D printer to induce liquid-phase formation in the sintering process, with the number of glass frit-ink prints controlled to selectively change the glass frit content, resulting in increased strength. Accordingly, this study successfully fabricated a tube-structured ceramic mesh with high porosity and a high-strength ceramic material covering the surface. Moreover, this study confirms the feasibility of manufacturing composite ceramics through ink synthesis using 3D printing technology and applying ceramic sintering behavior. Furthermore, the application of this novel technology to realize more diverse and complex properties in 3D was verified.