Abstract
The influence of SiC dispersion on the sintering behavior and mechanical properties has been investigated for the B4C/SiC composite system. Nearly full dense composites were obtained by hot-pressing in an argon atmosphere at 2200°C for 30 min. The maximum bending strength and francture toughness were obtained for the compsite containing 20 vol%SiC prepared hot-pressed at 2200°C for 30 min. The bending strength increased from 620 MPa for the monolithic B4C to 750 MPa for the B4C/20 vol%SiC compositee and fracture toughness showed a similar trend from 3.9 to 4.9 MN/m3/2. Scanning electron microscopy was used to analyze crackmicrostructure interactions. Fractography indicated that the crack deflection and bridging by SiC particles might be the main toughening mechanisms for this composite system.
