Formation studies of TiC from carbon coated TiO2

This paper deals with the formation of titanium carbide from carbon coated titanium dioxide precursors. This study makes use of differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X-ray diffraction (XRD ), and both scanning and transmission electron microscopy (SEM and TEM). DS C curves of both coated and mixed 33.2 wt % carbon containing titania demon strates the superiority of the coated precursor by exhibiting both more rea ctions and reactions at lower temperatures than the mixed powder. Weight lo ss as powders were reacted in argon at varying temperatures was measured us ing TGA, while heat flow vs. temperature was measured by DSC. The weight lo ss allowed for calculation of the activation energy of TiC via the formatio n of various lower oxides of titanium. The activation energy was calculated as 731.6 +/- 24.2 kJ/mol. XRD was used to characterize the products result ing from the reaction of the carbon coated precursor at isotherms at each 1 00 degrees C interval from 1100 to 1500 degrees C, inclusive. These diffrac tion patterns support the hypothesis that the TiC formation proceeds throug h the formation of lower oxidation states of titanium. (C) 1999 Kluwer Acad emic Publishers.