First-principles calculations to investigate adhesion strength, stability and electronic properties of Al(111)/TiAl₃(112) interface

The structure, adhesion work, interfacial energy, interfacial fracture toughness and electronic properties of the Al(111)/TiAl₃(112) interface were investigated based on first-principles calculations. The number of convergent layers on the surface of Al(111) and TiAl₃(112) is discussed, and it is more suitable to stack 7 layers of Al(111) on 5 layers of TiAl₃(112). The established interfacial structure was optimized, and the UBER method and the complete relaxation method were used to determine the optimal interfacial distance and work of adhesion. The Ti-HCP interface has the smallest surface energy and the largest adhesion work, indicating that it is the most stable. The Ti-HCP density of states map shows that for atoms in the first layer of Al(111) and TiAl₃(112), some orbital hybridization peaks can be seen, especially for Al-P and Ti-d orbitals. These resonance peaks imply covalent interactions between Al-P and Ti-d. (author)