High-temperature mechanical properties of ZrB2/SiC/Si3N4 ceramic tool materials with dual composite architectures.

ZrB 2 /SiC ceramic granules with uniform a size and spherical shape were prepared by spray drying technology. ZrB 2 /SiC ceramic granules were added into ceramic matrix, and ZrB 2 /SiC/Si 3 N 4 ceramic tool materials with double composite architectures were prepared by spark plasma sintering technology. The mechanical properties from room temperature to 1100°C were measured. The hardness, flexural strength and fracture toughness at room temperature are 18.0 GPa, 589.0 MPa and 5.93 MPa m1/2, respectively. While the fracture toughness at 1100°C reach 6.1 MPa m1/2 increase by 74.3% compared with the ceramic tool material without double composite architectures. At high temperature, the improvement of fracture toughness is due to the addition of ZrB 2 /SiC ceramic granules that deflect the cracks and propagates along the boundary between the granules and the matrix, which greatly increase the path during the crack propagation process, thereby improving the fracture toughness of the ceramic tool material. [ABSTRACT FROM AUTHOR]