Influence of alloying elements on stability and adhesion ability of TiAl/TiO2 interface by first-principles calculations

First-principles calculations were performed to study the adhesion of the M alloyed TiAl and TiO2 interface (M = Si, Cr, Co, Ni, Y, Zr, Nb, Mo, Pd, and W). The occupation of alloying elements in the TiAl/TiO2 interface was examined and the influence of alloying elements on the adhesion of the interface was then clarified. The alloying elements stabilize both the TiAl surface and TiAl/TiO2 interface but with different degrees.The Y, Nb and Pd greatly improve the adhesion of TiO2 on TiAl matrix, while others illustrate relatively weak effect. The geometric configuration and electronic structures of elements in the interface zone were studied to investigate the bonding interactions between the alloyed TiAl and TiO2 layers. The oxygen atoms are found to be the adhesion media connecting the alloyed TiAl and TiO2 slabs in the TiAl/TiO2 interface and may affect the spallation of oxide scale from TiAl matrix.