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从电子层面系统研究Fe-Cr-Al合金氧化膜的形成机理,杂质硫对氧化膜黏附性的影响,稀土元素在改善氧化膜黏附性方面的作用,揭示合金氧化的物理本质.研究表明氧使Al在合金表层的环境敏感镶嵌能最低,促使Al原子从合金内部向合金表面扩散,最终在合金表面偏聚.由于氧与Al间的亲和力较大,氧原子易与Al结合生成Al2O3保护膜.杂质S在基体/氧化膜界面的环境敏感镶嵌能较低,可通过扩散偏聚在基体/氧化膜界面,削弱氧化膜与合金基体的结合力.当合金中加入Y后,Y易与S结合形成稳定的硫化物,阻碍S向基体/氧化膜界面的偏聚,显著提高氧化膜的黏附性,提高合金抗高温氧化能力.
The formation mechanism of Fe-Cr-Al alloy oxide film, the effect of impurity sulfur on the adhesion of oxide film, the effect of rare earth elements on improving the adhesion of oxide film were studied systematically from the electron level to reveal the physical nature of the oxidation of the alloy. Due to the high affinity between oxygen and Al, the oxygen atoms can easily combine with Al to form Al2O3 protective film. Impurity S at the substrate / oxide film of the environment-sensitive mosaic can be low, can be dispersed by segregation in the matrix / oxide film interface, weakening the adhesion of the oxide film and the alloy matrix.When Y is added to the alloy, Y easily combined with S The formation of a stable sulfide, hinder the S to the substrate / oxide film segregation, significantly improve the adhesion of the oxide film, improve the ability of high temperature oxidation of the alloy.