Low-temperature sintering behavior and mechanical properties of BN-ZrO2-SiC composites

A novel pressure-assisted transient viscous phase sintering process has been used to fabricate dense BN-ZrO2-SiC composites at relatively low sintering temperatures. The sintering behavior and densification mechanism of BN-ZrO2-SiC composites incorporated with B2O3 as transient viscous phase have been investigated. A rapid densification process occurs at about 1300 °C, which is attributed to the in-situ formation of SiO2 by chemical reactions among ZrO2, SiC and B2O3. BN-ZrO2-SiC composites sintered at 1300 °C under 100 MPa exhibit a relative density of 95.9%, a flexural strength of 242 MPa and a fracture toughness of 4.1 MPa m1/2.