Effect of Ce in Al-Ti-B-Ce Refiner on TiAl3/α-Al Heterogeneous Nucleation Interface by First-Principles Study

The segregation behavior, the stability and strengthening energy, and the electronic structure of Ce at the TiAl 3 /α-Al interface was studied by first-principles method to understand the mechanism of the action of Ce on the second phase TiAl 3 in Al-Ti-B-Ce refiner. The results show that Ce can spontaneously segregate at the nucleation interface of TiAl 3 and Al to improve the stability of TiAl 3 /α-Al interface, and the stability of Ce central site of TiAl 3 (001) Al /Al (001) interface(0A0H) is the strongest. As for 0A0H interface, Ce has little effect on the electronic structure of Al (001) side of TiAl 3 /α-Al interface which limits its direct refinement effect on α-Al, while there is a strong bonding force to Al atoms on the TiAl 3 (001) side to reduce the surface energy of TiAl 3 , change the selective growth orientation of TiAl 3 , and provide more nucleation substrate to promote α-Al nucleation on the TiAl 3 surface.