Abstract: Effects of Yb2 O3 content on the phase composition, microstructural and mechanical properties of yttria stabilized zirconia toughened alumina were investigated. The density, mechanical properties, microstructure and physical composition were analyzed by Archimedes, three point bending, scanning electron microscope, and X-ray diffraction. The results show that the maximum value of fracture toughness, bending strength and hardness of ZTA was 7. 42 MPa·m1/2、623. 10 MPa and 1919. 60 HV without any addition of Yb2 O3 respectively. However, with Yb2 O3 addition, the phase and the mechanical properties of ZTA were changed. The pahse of zirconia from tetragonal to cubic and a new phase Yb3 Al5 O12 appeared. Finally, the mechanical properties of ZTA were reduced, especially, the fracture toughness reduced by 30. 7; compared to without additives.

Key words: Effects of Yb2 O3 content on the phase composition, microstructural and mechanical properties of yttria stabilized zirconia toughened alumina were investigated. The density, mechanical properties, microstructure and physical composition were analyzed by Archimedes, three point bending, scanning electron microscope, and X-ray diffraction. The results show that the maximum value of fracture toughness, bending strength and hardness of ZTA was 7. 42 MPa·m1/2、623. 10 MPa and 1919. 60 HV without any addition of Yb2 O3 respectively. However, with Yb2 O3 addition, the phase and the mechanical properties of ZTA were changed. The pahse of zirconia from tetragonal to cubic and a new phase Yb3 Al5 O12 appeared. Finally, the mechanical properties of ZTA were reduced, especially, the fracture toughness reduced by 30. 7; compared to without additives.