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In this research, we creatively integrate the traditional methods of liquid precursor infiltration plus in-situ precipitation with stereolithography-based 3D printing for the fabrication of Al 2 O 3 -ZrO 2 ceramics to ensure the homogeneous distribution of ZrO 2 particle in the alumina matrix. Our characterization results shows that this combination leads to the materials with significantly better performance. The Al 2 O 3 specimen is soaked in a Zr 4+ ion solution to induce infiltration, in-situ precipitation and then sintered. X-ray diffraction analysis of the thus-treated sample indicated that Al 2 O 3 was the primary phase and t-ZrO 2 was the secondary phase. Microstructural and EDS analysis showed that the ZrO 2 particles were homogeneously distributed in the Al 2 O 3 matrix, leading to inhibited grain growth. The samples soaked in solutions for different Zr 4+ concentrations and sintered both at 1450 °C and 1550 °C showed improved mechanical properties as compared to those of pure alumina. Futhermore, the sample infiltrated using the solution with a concentration of 1.5 mol/L and sintered at 1450 °C showed similar fracture toughness (4.97 MPa m 1/2 ) with the sample sintered at 1550 °C (5.06 MPa m 1/2 ) but much better hardness (20.95 Gpa) than the sample sintered at 1550 °C (19.71 GPa). Therefore, this method could not only enhance the mechanical properties via introducing the second phase, but also lowers the sintering temperature by at least 100 °C, which would be beneficial for energy conservation and leads to significant advances in the 3D printing of ceramic components. [ABSTRACT FROM AUTHOR]

In this paper, a ceramic suspension with appropriate viscosity was prepared by optimizing the powder solid content and the dispersant content. An Al 2 O 3 -ZrO 2 ceramic green body was fabricated using the SLA technique, followed by the application of a liquid drying and two-step debinding process to prepare the defect-free Al 2 O 3 -ZrO 2 ceramic green body. The relative density, phase composition, microstructure, grain size, and mechanical properties of Al 2 O 3 -ZrO 2 samples sintered at different temperatures were compared. The main results indicated that the sample density increased with the sintering temperature until reaching a maximum density of 4.28 g/cm 3 at 1600 °C. When the temperature further increased to 1650 °C, the density dropped instead. With increasing sintering temperature, both the number of grain boundaries and the number of pores located at the grain boundaries reduced greatly. The Vickers hardness of the samples first increased and reached its maximum at 1550 °C with a value of 17.6 GPa, and then decreased with further increases in sintering temperature. The fracture toughness increased with the sintering temperature and reached a maximum value of 5.2 MPa·m 1/2  at 1650 °C. A sintering kinetics window which could offer the relationship between the sintering temperature and the relative density & grain size was set and also the microstructure evolution of the sintered body was conducted to get a deeper understanding of the 3D printing Al 2 O 3 -ZrO 2 composites. [ABSTRACT FROM AUTHOR]