Titanium carbide has been widely considered as a stabilizer to alleviate the serious chemical activity of Ti-based alloys at elevated temperatures. However, a reverse effect may also take place: we show the sub-stoichiometry characteristic of δ-Ti_xC can facilitate the oxidation kinetics of a Ti-6Al-4V alloy to a significant extent. In particular, oxygen atoms tend to preferentially occupy the vacant carbon sites within the Ti₂C phase, giving rise to a higher oxidation rate. The intrinsic mechanisms were understood with a combination of ab initio simulation and experimental validation.

中文翻译：

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δ-Tix C掺杂的Ti基合金中亚化学计量促进的氧化动力学

碳化钛已被广泛认为是稳定剂，可减轻高温下Ti基合金的严重化学活性。然而，相反的效果也可能发生：我们显示δ-Ti系的子化学计量特性_X C能够促进一个Ti- 6Al-4V合金的氧化动力学的显著程度。特别地，氧原子倾向于优先占据Ti ₂ C相内的空碳位，从而导致更高的氧化速率。从头算模拟和实验验证相结合，了解了内在机制。