We apply the first-principles calculations to investigate the influence of Cr and Y on the oxidation resistance of RuAl(1 1 0) surface. Four possible oxygen adsorption sites: Al-top, Ru-top, Ru-bridge and Al-bridge are considered. It is found that the capacity of oxidation resistance of Ru is stronger than that of Al. Oxygen atom is adsorbed on the Ru-bridge site because of the strong charge interaction between Ru and the O. Importantly, the calculated adsorption energy of Cr-doped RuAl(1 1 0) surface is −0.350 eV, which is smaller than that of Ru-bridge site. The calculated result indicates that Cr-dopant can improve the oxidation resistance of RuAl(1 1 0) surface. The reason is that Cr-dopant improves the localized hybridization between Cr atom and the O atom, and weakens the charge interaction of Ru-O atoms and Al-O atoms. Therefore, we predict that Cr is a beneficial element to improve the oxidation resistance of RuAl thermal barrier coating.

我们应用第一性原理计算来研究Cr和Y对RuAl（1 1 0）表面抗氧化性的影响。考虑了四个可能的氧吸附位点：Al-top，Ru-top，Ru-bridge和Al-bridge。发现Ru的抗氧化能力强于Al。由于Ru和O之间的强电荷相互作用，氧原子被吸附在Ru桥位上。重要的是，计算出的Cr掺杂RuAl（1 1 0）表面的吸附能为-0.350 eV，小于汝桥遗址。计算结果表明，Cr掺杂剂可以提高RuAl（1 1 0）表面的抗氧化性能。原因是Cr-掺杂剂改善了Cr原子和O原子之间的局部杂化，并削弱了Ru-O原子和Al-O原子的电荷相互作用。因此，