Effect of temperature on oxidation behaviour of Ga-containing near-α Ti alloy. (1st April 2018)

• Record Type: Journal Article
• Authors: Yang, Y.; Kitashima, T.; Hara, T.; Hara, Y.; Iwasaki, S.
• Is Part Of: Corrosion science. Volume 133(2018)
• Page Start: 61
• Page End: 67
• Publication Date: 2018-04-01
• Subjects: Titanium alloy -- Oxidation -- Recrystallization -- Gallium addition -- Temperature dependence; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2018.01.018
• Languages: English
• ISSNs: 0010-938X

Abstract

Highlights: High-temperature oxidation of a Ga-containing near-α Ti alloy was investigated in the temperature range from 650 °C to 750 °C. The oxidation rates of the Ga-containing Ti alloy were lower than those of Ti–6Al–4 V and Ti–6Al–2Sn–4Zr–2Mo. Alloy recrystallization at the oxide/metal interface was observed at 700 °C and accelerated at 750 °C, but did not occur at 650 °C. The recrystallization process had little effect on the alloy weight gain due to O penetration. Abstract: Isothermal oxidation testing of a Ga-containing near-α Ti alloy was performed in air at 650, 700, and 750 °C for up to 500 h. Results revealed that the alloy oxidation kinetics followed a parabolic law at 650 °C and a parabolic–cubic law at 700 and 750 °C, while the abundance of Al2 O3 in the oxide layers increased with temperature after the dissolution of Ga2 O3 species in the Al2 O3 phase. The activation energy of the α-case formation was close to the magnitudes obtained for conventional Ti alloys despite its temperature-dependent recrystallization near the oxide/metal interface at 700 and 750 °C.