Oxidation kinetics and microstructure evolution of air oxidation behavior of TC18 alloy. (October 2022)

• Record Type: Journal Article
• Authors: Xi, Aiying; Zhuo, Longchao; Shao, Hui; Shan, Di; Sun, Feng; Lu, Jinwen; Ji, Kaile; Chen, Bingqing; Zhao, Xiaohua; Wang, Kaixuan
• Is Part Of: Vacuum. Volume 204(2022)
• Publication Date: 2022-10
• Subjects: TC18 alloy -- High-temperature oxidation -- Oxide layer -- Oxidation kinetics; Vacuum -- Periodicals; 621.55
• DOI: 10.1016/j.vacuum.2022.111332
• Languages: English
• ISSNs: 0042-207X

Abstract

Abstract: The high-temperature air oxidation behaviors at 600 °C, 700 °C and 800 °C of the TC18 alloy were systematically studied. The oxidation kinetics of TC18 alloy, the phase composition, microscopic morphology and chemical composition of the surface oxide films were analyzed to elucidate possible oxidation mechanisms. The results revealed that the oxidation behavior of TC18 alloy followed a linear-parabolic law at 600 °C and 700 °C while being governed by a simple linear law at 800 °C. The long-term oxidation for 24 h at 600 °C and 700 °C resulted in the oxide films composed of both Ti3 O and TiO2, with dominant Ti3 O and TiO2 respectively for the oxide films formed at 600 °C and 700 °C specifically. Especially for the oxidation at 800 °C, the oxide film was revealed to consist of three layers of the outer layer Al2 O3, the secondary outer layer TiO2 and the dominant inner layer TiO2 . Highlights: Air oxidation behaviors of TC18 alloy at 600–800 °C for 1–24 h were studied. Kinetics changed from linear-parabolic to linear type with increasing temperature. Oxide films of TiO2 and Ti3 O formed in the samples oxidated at 600 °C and 700 °C. The oxide layer of Al2 O3, TiO2 and Ti3 O formed in the sample oxidated at 800 °C. Titanium oxides grew at oxide-film/matrix interface, while Al2 O3 grew at the outer surface of oxide-film.