A New Approach to 3D Printing Dense Ceramics by Ceramic Precursor Binders

Fabrication of dense ceramic objects by 3D printing processes is important in achieving improved functions in many applications, such as mechanical, optical, and electrical devices. It is a challenging process, mainly due to the high content of organic binders within the printed object. Upon heating and sintering, the printed object shrinks and becomes porous due to the decomposition of the organic binder. Herein, a new approach is presented based on the utilization of an inorganic binder that is a sol-gel precursor for the same material composing the dispersed ceramic particles. The approach is demonstrated in printing objects composed of barium titanate (BTO), which is an important dielectric and piezoelectric material. This binder also enables us to achieve dispersions with high solid load that exhibits a shear-thinning rheological behavior, which is essential for direct ink writing (DIW) printing technology. The as-printed parts contain only 1 wt% organic materials, having 97.8% of the theoretical density, whereas the BTO binder crystalizes upon heating, without forming undesired secondary phases.