Single-source-precursor synthesis, microstructure and high temperature behavior of TiC-TiB2-SiC ceramic nanocomposites

Newly developed TiC-TiB2-SiC ceramic nanocomposites were successfully synthesized by a novel single-source-precursor approach, with allylhydridopolycarbosilane (AHPCS), bis(cyclopentadienyl) titanium dichloride (Cp2TiCl2) and triethylamine borane (TEAB) as starting materials. The obtained single-source-precursor was characterized by Fourier transform infrared spectra (FT-IR), which confirms that hydroboration (C=C/B-H) and dehydrochlorication (Si-H/Cp2TiCl2) reactions were involved to introduce B and Ti elements into the AHPCS chains. The structural evolution of single-source-precursors, phase composition and chemical composition of the obtained ceramics were investigated by FT-IR, X-ray diffraction (XRD) and elemental analysis. High temperature behavior of the resultant TiC-TiB2-SiC ceramic nanocomposites with respect to decomposition as well as crystallization was carefully checked by XRD and mass loss after annealing at high temperatures of 1600 and 1800 °C. Transmission electron microscopy (TEM) was used to further observe the microstructure of TiC-TiB2-SiC nanocomposites, which again confirms the crystalline phases consist of nanoscaled β-SiC, TiC and TiB2.