Mechanism of the high temperature oxidation of titanium carbide

High-temperature oxidation of titanium carbide in the temperature range of 600-1200 deg C in air has been studied by TGA, XRD, SEM, and AES methods. Oxidation kinetics is multistage. The time intervals and temperature dependence of the rate constants of three parabolic and linear stages for oxidation at temperatures 900-1200 deg C were determined. According to SEM and XRD data, a two-layer scale was formed at temperatures exceeding 1000 deg C. The outer scale consisted mainly of TiO sub 2 (rutile). The inner scale consisted of various titanium oxides. The effect of diffusion of both Ti and oxygen on the oxidation processes was studied. The mechanism of the oxidation process is discussed.