Effect of TiB2 content on microstructure and mechanical properties of SiC composite ceramics by solid-state spark plasma sintering

SiC-TiB2 composite ceramics of the solid-state has stable property in high temperature with wide application. In the paper, SiC-TiB2 composite ceramics was prepared by spark plasma sintering with 50 MPa pressure and heat preservation for 10 min at 1750 C-degrees, and the effect of TiB2 content (0 vo l%-20 vol%) on microstructure and mechanical properties of SiC composite ceramics by solid-state spark plasma sintering was investigated. The experimental results show that the grain growth of SiC is inhibited with the increase of TiB2 content. When TiB2 content is 20 vol%, TiB2 promotes the decomposition of SiC into Si, which is located in the grain boundaries of SiC and TiB2 to reduce mechanical properties of composite ceramics. SiC-15 vo l%TiB2 composite ceramics have the preferable comprehensive mechanical properties with relative density, Vickers hardness, bending strength and fracture toughness of 98.8%, 27.2 GPa, 431 MPa and 5.24 MPa center dot m(1/2), respectively.