Influence of ZrH2 addition on pulsed electric current sintered ZrB2-SiC composites

The beneficial effects of ZrH2 addition on the densification, microstructure and mechanical properties of pulsed electric current sintered ZrB2-SiC composites were investigated. The addition of ZrH2 removed B2O3 on ZrB2 particle surfaces, introduced a ZrC phase to the composites, and refined the SiC particle size during the sintering process. As a result, the three-point flexural strength and the fracture toughness of the ZrB2-SiC composite ceramic increased from 569 MPa and 3.9 MPa m1/2 to 998 MPa and 4.8 MPa m1/2, respectively.