First-principles study of the Ti(0001)/TiAl3(110) interfacial properties

Abstract

The structure, adhesion work, interface energy and electronic properties of Ti /TiAl3 interface were studied based on first-principles calculations. The number of convergent layers on the TiAl3(110) surface was discussed. The surface spacing of the first three layers’ changes more dramatically when surface relaxation is performed. The six interface structures established were optimized. The UBER method and the complete relaxation method were used to determine the optimal interfacial distance and adhesion work. It is found that the adhesion work of the TiAl-HCP interface is the largest and the interfacial distance is the smallest. In the study of interfacial energy, the TiAl-HCP interface structure exhibits the highest interfacial energy. The interfacial electronic structure with negative interfacial energy was studied. The calculated results of the differential charge density at the interface show that the TiAl-HCP has the greatest degree of charge transfer at the interface and the greatest interaction between atoms. The density of states map at the TiAl-HCP interface indicates that the 3d electron orbitals of the first layer of Ti atoms on the Ti (0001) surface and the 3p electron orbitals of the first layer of Al atoms of TiAl3(110) have orbital hybridization.