Microstructure and mechanical properties of 3Y-TZP/Al2O3 composites fabricated by liquid phase sintering

3Y-TZP/Al₂O₃ composites were pressureless sintered with the addition of TiO₂-MnO₂ and CaO-Al₂O₃-SiO₂ glass. The densification, microstructure and mechanical properties of the composites were investigated. It was found that the composites could be densified at a temperature as low as 1400^C by liquid phase sintering. The majority of the grain sizes for both Al₂O₃ and ZrO₂ were below 1 m because of the lower sintering temperature. A bending strength of 934 ± 28 MPa and fracture toughness of 7.82 ± 0.19 MPam^1/2 were obtained for 3Y-TZP/Al₂O₃ (20 vol%) composite. Transformation toughening is considered the responsible toughening mechanism.