Infuluence of sintering technology on microstructure and mechanical properties of YAG/ZrB2 ceramics

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 Al2O3-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 1300 degrees C to 1700 degrees C, 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 1700 degrees C, 20 MPa and 4 minutes, the Young's modulus and the fracture toughness are 430 GPa and 3.76 MPam(1/2), 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.