Because ZrB2 has some excellent physical performance and chemical stability, it has been widely applied in a lot of fields, but sintering of ZrB2 is too difficult to be densified and easy oxidation at high temperature. To keep advantages and improve disadvantages of ZrB2, the shell-core structure A12O3-Y2O3/ZrB2 composite powders are prepared by the co-precipitation methods, the high density YAG/ZrB2 ceramics is prepared by the spark plasma sintering (SPS). The increasing ratio of mehanical properties is faster at sintering temperature from 1300oC to 1700oC, the increasing ratio of mehanical properties is faster under sintering pressure from 5MPa to 20 MPa, the increasing ratio of mehanical properties is faster for holding time from 1 minute to 4 minutes. When the sintering conditons is 1700oC, 20 MPa and 4 minutes, the Young's modulus and the fracture toughness are 430 GPa and 3.76 MPam1/2, respectively. The YAG is coated on the surface of ZrB2 crystal, that is to say, the YAG is show on the crystal boundary, which is help for the densification and the oxidation resistance at hightemperature condition.

Keywords: ZrB2, Microstructure, Mechanical property, Co-precipitation methods, Spark plasma sintering.