Microstructure and mechanical properties of hot-pressed B 4C/TiC/Mo ceramic composites

Abstract

Boron carbide (B 4C)/TiC/Mo ceramic composites with different content of TiC were produced by hot pressing. The effect of TiC content on the microstructure and mechanical properties of the composites has been studied. Results showed that chemical reaction took place for this system during hot pressing sintering, and resulted in a B 4C/TiB 2/Mo composite with high density and improved mechanical properties compared to monolithic B 4C ceramic. Densification rates of the B 4C/TiC/Mo composites were found to be affected by additions of TiC. Increasing TiC content led to increase in the densification rates of the composites. The sintering temperature was lowered from 2150 °C for monolithic B 4C to 1950 °C for the B 4C/TiC/Mo composites. The fracture toughness, flexural strength, and hardness of the composites increased with increasing TiC content up to 10 wt.%. The maximum values of fracture toughness, flexural strength, and hardness are 4.3 MPa m 1/2, 695 MPa, and 25.0 GPa, respectively.