Effect of temperature on the structure and mechanical properties of SiC–TiB2 composite ceramics by solid-phase spark plasma sintering

Abstract

SiC composite ceramics have good mechanical properties. In this study, the effect of temperature on the microstructure and mechanical properties of SiC–TiB2 composite ceramics by solid-phase spark plasma sintering (SPS) was investigated. SiC–TiB2 composite ceramics were prepared by SPS method with graphite powder as sintering additive and kept at 1700 °C, 1750 °C, 1800 °C and 50 MPa for 10min.The experimental results show that the proper TiB2 addition can obviously increase the mechanical properties of SiC–TiB2 composite ceramics. Higher sintering temperature results in the aggregation and growth of second-phase TiB2 grains, which decreases the mechanical properties of SiC–TiB2 composite ceramics. Good mechanical properties were obtained at 1750 °C, with a density of 97.3%, Vickers hardness of 26.68 GPa, bending strength of 380 MPa and fracture toughness of 5.16 MPa m1/2.