Abstract:
The effect of silicon and Ti$_5$Si$_3$ films on the adhesion properties of the $\alpha$-Al$_2$O$_3$/$\gamma$-TiAl interface and oxygen diffusion in TiAl was studied using the projector augmented-wave method within density functional theory. It was shown that the formation of intermediate silicide layers at the oxide–alloy interface can lead to a significant decrease in the oxygen diffusion coefficient. At the same time, adhesion at the oxide–silicide interface remains high, while for the silicide–alloy interface, the values of $\sim$2.26–2.80 J/m$^2$ typical for interfaces with metallic and metal-covalent bonds were obtained.
Keywords:titanium aluminides, titanium silicide, oxygen diffusion, adhesion, the ab-initio calculations.
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