Studies of the oxidation of titanium in carbon dioxide—II. Characteristics at reaction temperatures of 900 and 1000°C

The oxidation of titanium in carbon dioxide has been assessed at reaction temperatures of 900 and 1000°C by gravimetric, metallographic and microhardness techniques. The overall kinetics were parabolic at 900°C and paralinear at 1000°C. The results in general showed considerable scatter, but it was established by a statistical analysis of data at 1000°C that the scatter was independent of specimen preparation method. Oxygen dissolution in metal substrates during oxidation was very extensive and it has been shown that the observed saturation after exposure for long times at 1000°C was associated with the parabolic/linear overall kinetic transition. Linear rates of scaling were observed in character with the porous and layered nature of the scales.