Preparation of ZTA composite ceramics derived from sol–gel method by DIW printing

In this study, the dense and fine-grained zirconia toughened alumina (ZTA) composite ceramics were efficiently prepared by 3D gel printing technology. Zirconia powder, zirconium oxychloride, and zirconium sol were introduced into boehmite gel as zirconium sources, and their effects on rheological properties, drying characteristics, microstructure, and mechanical properties of ceramics were discussed. The results showed that all gels exhibit reversible shear thinning properties. The gel with zirconia powder has a relaxation phenomenon; zirconium sol forms another gel network in the boehmite gel network, and two linear viscoelastic regions are observed. The gel with zirconia powder has the highest solid loading, small drying shrinkage, and fewer drying defects. The grain growth of ZTA ceramics with zirconium sol was inhibited, and the zirconia grains were evenly distributed, with the highest bending strength of 518 ± 103 MPa. The new gel preparation method and gel drying process offer great possibilities for manufacturing optical glasses and functional ceramics with high-performance geometric structures, which cannot be achieved by traditional manufacturing methods.