The high-temperature oxidation behavior of Ti–6 mass%Al–4 mass%V alloys have been investigated in temperature ranges of 773 to 973 K, and 1123 to 1273 K, in air. A kinetic study of the oxidation has been also carried out in Ti–6 mass%Al–4 mass%V alloy. The oxidation products have been examined by X-ray diffraction (XRD), electron probe microanalysis (EPMA) and X-ray photoelectron spectroscopy (XPS). The banded Al
2O
3 layer is probably formed in the oxides of the Ti–6 mass%Al–4 mass%V alloy by means of EPMA, although the rutile TiO
2 is mostly detected by means of XRD in the oxides of surface layer in the alloy at 1273 K. Furthermore, the TiO
2 and Al
2O
3 are observed by XPS in surface of the above alloy at 1123 K for 3.6 ks, but the V
2O
5 is not observed. It is found that the apparent activation energy for the isothermal oxidation in the Ti–6 mass%Al–4 mass%V alloys is
Qi=223 kJ/mol, and the activation energy for the non-isothermal oxidation (TG experiment) at a constant heating rate is
Qa=209 kJ/mol in the present alloys.
抄録全体を表示