CARBOTHERMAL SYNTHESIS OF TITANIUM CARBIDE USING ULTRAFINE TITANIA POWDERS

The synthesis of titanium carbide (TiC) by the carbothermal reduction of carbon coated titanium dioxide (TiO2), a novel synthesis process, a nd titanium dioxide (TiO2) mixed with carbon black was investigated. A high surface area (64 m(2) g(-1)) TiO2 powder consisting of anatase a nd rutile phases was used for starting powders. The carbon coated meth od is a two-step process that utilizes a precursor derived from decomp osing propylene (C3H6) and depositing carbon on the TiO2 particles. Ti O2 powders were also mechanically mixed with carbon black for comparis on. Both starting precursors and mixtures were reacted in a tube furna ce for 2 and 4 h at temperatures of 1100 degrees C to 1550 degrees C u nder 1 l min(-1) flowing argon. The TiC powders were characterized usi ng thermogravimetric analysis (TGA), X-ray diffraction (XRD), Brunauer -Emmett-Teller (BET) surface area analyser, chemical analysis (oxygen and carbon) and transmission electron microscopy (TEM). The carbon coa ting process provides high contact area between the reactants which re sults in a TiC product with lower oxygen content (0.6 wt %), finer par ticle size (0.1 mu m), and uniform shape when synthesized at 1550 degr ees C for 4 h.