Fabrication of high-performance Al 2 O 3 -ZrO 2 composite by a novel approach that integrates stereolithography-based 3D printing and liquid precursor infiltration

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 Al2O3-ZrO2 ceramics to ensure the homogeneous distribution of ZrO2 particle in the alumina matrix. Our characterization results shows that this combination leads to the materials with significantly better performance. The Al2O3 specimen is soaked in a Zr4+ ion solution to induce infiltration, in-situ precipitation and then sintered. X-ray diffraction analysis of the thus-treated sample indicated that Al2O3 was the primary phase and t-ZrO2 was the secondary phase. Microstructural and EDS analysis showed that the ZrO2 particles were homogeneously distributed in the Al2O3 matrix, leading to inhibited grain growth. The samples soaked in solutions for different Zr4+ 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 m1/2) with the sample sintered at 1550 °C (5.06 MPa m1/2) 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.