Preparation and Properties of TiB_2-SiC-Si Composites Fabricated by Reaction Bonding

摘要

TiB_2-SiC-Si composite was fabricated by reaction bonding. The influence of carbon content on the phase compositions, microstructure, density and mechanical properties was studied. The results showed that the composite consists of TiB_2, SiC and Si phases. The vol% of SiC increased with the increase of C contents, while that of TiB_2 and free silicon reduced respectively. The mechanical properties of TiB_2-SiC-Si composites are improved initially and then deteriorated with the increase in C contents of which the optimal amount is 8 %. The optimum open porosity, volume density, Vikers-hardness, flexural strength and fracture toughness of the obtained TiB_2-SiC-Si composite are 0.12 %, 3.73 g/cm~3, 17 GPa, 290 MPa and 5.9 MPa-m~(1/2), respectively.