High-Temperature Oxidation and Its Kinetics Study of Ti-Al and Ti-V Alloys in Air

• Published in: Keikinzoku Vol. 64; no. 2; p. 56
• Main Authors: Takahashi, Tomoshi, Minamino, Yoritoshi, Hirasawa, Hideyuki, Ouchi, Tadashi
• Format: Journal Article
• Language: English; Japanese
• Published: 01.02.2014
• Subjects: Activation energy; Alloys; Intermetallic compounds; Oxidation; Oxides; Titanium base alloys; Titanium dioxide; X-ray photoelectron spectroscopy; X-rays
• ISSN: 0451-5994; 1880-8018
• DOI: 10.2320/matertrans.L-M2013840

The high-temperature oxidation behavior of Ti-(6-36)mass%Al alloys and Ti-(4-15) mass%V alloys has been investigated in a temperature range of 1123 to 1273 K in air. A kinetic study of the oxidation has been also carried out in Ti-6 mass%Al alloy and Ti-4 mass%V alloy. The growth rate of oxides of Ti-V alloys is larger than that of Ti-Al alloys. The oxidation products have been examined by X-ray diffraction (XRD), electron probe microanalysis (EPMA) and X-ray photoelectron spectroscopy (XPS). The Al sub(2)O sub(3) layer is probably formed in the Ti-Al/oxides interface of the Ti-6mass%Al alloy according to the results by means of EPMA, although only the rutile TiO sub(2) is detected by means of XRD in the oxides of surface layer in Ti-6mass% Al alloy and Ti-4 mass%V alloy at 1273 K. Furthermore, the TiO sub(2) and Al sub(2)O sub(3) are observed by XPS in the surface layer of the above both alloys oxidized at 1123 K for 3.6 ks, but the V sub(2)O sub(5) is not observed. It is found that the apparent activation energy (245 kJ/mol) for the oxidation experiment (TG experiment) at a constant heating rate is fairly equal to the activation energy (253 kJ/mol) for the isothermal oxidation in Ti-6mass%Al alloys.