Synthesis, microstructure, and mechanical properties of TiC-SiC-Ti3SiC2composites prepared by in situ reactive hot pressing

In this work, TiC-SiC-Ti(3)SiC(2)composites were synthesized by in situ reactive hot pressing using beta-SiC, graphite, and TiH(2)powders as initial materials. Microstructure and mechanical properties of as-prepared dense composites were systematically investigated. It was found that by increasing the initial SiC content the final SiC content in the composites increased in contrast to the decrease in TiC and Ti(3)SiC(2)contents. In the dense composites, TiC and Ti(3)SiC(2)grains exhibited transgranular fracture, whereas SiC particles showed intergranular fracture. The composite containing 77 vol.% TiC, 4 vol.% SiC, and 19 vol.% Ti(3)SiC(2)had the highest flexural strength of 706.6 MPa. The composite consisting of 44 vol.% TiC, 49 vol.% SiC, and 7 vol.% Ti(3)SiC(2)exhibited the highest Vickers hardness of 22.3 GPa and the highest fracture toughness of 6.0 MPa center dot m(1/2).