A combined experimental and first-principle study on the effect of plasma surface Ta–W co-alloying on the oxidation behavior of γ-TiAl at 900 °C. Issue 5 (16th March 2020)

• Record Type: Journal Article
• Authors: Wei, Dongbo; Li, Fengkun; Li, Shuqin; Wang, Shiyuan; Ding, Feng; Liang, Hongxuan; Yan, Yuqin; Zhang, Pingze
• Is Part Of: Journal of materials research. Volume 35:Issue 5(2020)
• Page Start: 516
• Page End: 526
• Publication Date: 2020-03-16
• Subjects: alloy, -- oxidation, -- simulation; Materials -- Research -- Periodicals; 620.1105
• DOI: 10.1557/jmr.2019.385
• Languages: English
• ISSNs: 0884-2914

Abstract

Abstract: Abstract : Ta–W co-alloying was realized by double glow plasma surface metallurgy technology, and their effects on high-temperature oxidation behavior of γ-TiAl were studied. Ta–W co-alloying coating was composed of a deposited layer and interdiffusion layer. The results of isothermal oxidation experiment indicated that a compact mixed oxide film of Ta and W was formed on the sample. The interdiffusion layer reduced the oxygen intrusion that improved the high-temperature oxidation resistance of γ-TiAl. The effects of Ta–W co-alloying on oxygen adsorption energy and electronic structure of γ-TiAl(111) were analyzed by first-principle calculation. The results showed that the optimal adsorption sites of O atoms changed from fcc-Al to hcp-Ti and hcp-Al, indicating that Ta–W co-alloying inhibited the diffusion of O. The electronic structure analysis of γ-TiAl(111) after Ta–W alloying indicated the affinity of Ti and O was inhibited, which resulted in decreased TiO2 in the oxide film.