粘结层中的Co对热障涂层界面结合因子的影响

用固体与分子经验电子理论(EET)和改进的TFD理论的结合,计算了热障涂层不同粘结层Co含量下的陶瓷层/粘结层界面的界面结合因子,结果表明:含Co界面的最小电子密度差Δρmin比不含Co时小,Co有利于缓解界面的应力;加Co后使该界面电子密度保持连续的原子状态组数σ′比不加Co至少增加一个数量级,Co有利于使界面稳定,且从σ_equal和σ_super可知这种稳定性不会由于应力的升高受到破坏;当粘结层的表面为(110)时,加Co后电子密度ρ总是提高,有利于提高界面的结合力;当粘结层的表面为(100)和 (111)时,界面的结合力不受Co含量影响。所以,Ni基粘结层中的Co可改善热障涂层的陶瓷层/粘结层的界面结合。

Influence of Co content of the bonding layer of the thermal barrier coatings on its interface conjunction factors

Interface conjunction factors of the interface of ceramic layer/bonding layer of thermal barrier coatings were calculated on various bonding layer Co contents with the combination of the empirical electron theory of solid and molecule (EET) and the improved Thomas-Ferim-Dirac theory. The following conclusions can be drawn with the calculated results. The minimum electron density difference Δρ _min of Co containing interface is smaller than that without Co, so Co is in favor of releasing interface. Furthermore,it can also be seen from σ_equal and σ_super that this stability will not be demaged by the increasing of stress.when the surface of bonding layer is(110) crystal plane,the electron density ρ is always promoted by the adding of Co,which id in favor of promoting the binding force of the interface.when the surface of the bonding layer is (100) or (111),the binding force will not be influenced by the Co content.therefore,Co in the Ni based bonding layer can improve the conjunction of the ceramic layer/binding layer interface of the thermal barrier coating.