Effects of Additives and Sintering Temperature on the Properties of 3D Printed Zirconia Ceramics

Affected by the layer-by-layer manufacturing characteristic of 3D printing, formed green bodies still face certain challenges in terms of densification behavior, microstructure uniformity and mechanical properties, which limits their application in the field of high-performance components. This study systematically investigates the effects of different types of additives (Al₂O₃, SiO₂, B₂O₃, TiO₂) on zirconia ceramics. The results show that the zirconia samples containing Al₂O₃ and SiO₂ exhibited relatively high flexural strengths, whereas no significant improvement in flexural strength was observed for the samples containing B₂O₃ and TiO₂. B₂O₃ and TiO₂ acted as sintering aids under the conditions of this experiment, merely improving the sintering degree while the strength of the samples remained almost unchanged. The flexural strength of samples containing 5wt.% Al₂O₃ sintered at 1550℃ was 61.7 ± 0.9 MPa, which was 220.3% higher than that of the samples without additives. The relative density was 69.3 ± 0.6% (corresponding to a bulk density of 4.09 ± 0.04 g/cm³), and the open porosity was 18.7 ± 0.5%. The flexural strength of the samples containing 5wt.% SiO₂ sintered at 1550℃ was 49.2 ± 2.0 MPa, which was 155.6% higher than that of the samples without additives. The relative density was 73.5 ± 0.8% (corresponding to a bulk density of 4.28 ± 0.04 g/cm³) and the porosity was 18.1 ± 0.5%. This study can provide experimental basis and technical references for the performance optimization of 3D-printed zirconia ceramics.