Microstructural, thermal and mechanical characterization of TiB2–SiC composites doped with short carbon fibers

Abstract

Spark plasma sintering method, at the temperature of 1800 degrees C under the pressure of 40 MPa for 7 min, was employed for fabrication of TiB2-SiC-based composites. The influences of short carbon fiber (C-f) addition (2 wt %) on microstructural, mechanical and thermal properties of TiB2-SiC ceramics were studied. Carbon fiber addition increased the relative density of sintered composite which observed to have direct effect on mechanical and thermal properties. The mechanical properties of composites were measured by nanoindentation method. Hardness and elastic modulus of TiB2/SiC interfaces in carbon fiber doped composite were measured 27.1 GPa and 445 GPa, respectively, while these values were obtained 24.2 GPa and 422 GPa for carbon-free sample. The thermal diffusivity of samples was measured by laser flash technique (LFT). It was found that TiB2-SiC-Cf composite has a higher thermal conductivity (55 w/m.K) compared to TiB2-SiC ceramic with a value of 54.8 w/m.K.