1. Mo-doped Cr-Ti-Mo ternary o-MAX with ultra-low wear at elevated temperatures.
- Author
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Du, Cheng-Feng, Xue, Yaqing, Zeng, Qingyan, Wang, Jinjin, Zhao, Xiangyuan, Wang, Zjiao, Wang, Chuanchao, Yu, Hong, and Liu, Weimin
- Subjects
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HIGH temperatures , *CERAMICS , *X-ray photoelectron spectroscopy , *DEPTH profiling , *MECHANICAL wear - Abstract
In this work, the Cr-Ti-Mo ternary o -MAX ceramics based on the Cr 2 TiAlC 2 phase are synthesized, and their tribological performance at elevated temperatures up to 800 ºC in the air is evaluated. With Si 3 N 4 as a tribocouple, an unexpected ultra-low wear rate reaching 6.1 × 10−8 mm3 N−1 m−1 is observed in Cr 1.9 Ti 0.9 Mo 0.2 AlC 2 at 800 ºC, accompanied by a stable coefficient of friction (COF) around 0.33 in a wide temperature range. X-ray photoelectron spectroscopy (XPS) depth profiling confirms a tribofilm with gradient composition, which simultaneously offers fluid lubricating at elevated temperatures and self-healing after cooling. Particularly, confirmed by the theoretical simulations, the doping of Mo improves the interlayer binding as well as alters the oxidation behaviors of Cr 2 TiAlC 2. With an optimal interlayer binding strength and oxidation rate, the Cr 1.9 Ti 0.9 Mo 0.2 AlC 2 can generate a tribofilm possessing ideal composition, which simultaneously promotes lubrication and anti-wear performance at elevated temperatures. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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