First-principles study of Al/A13Ti heterogeneous nucleation interface

The interfacial adhesion, stability, wetting, and bonding nature of Al(1 1 1)/Al3Ti(1 1 2) and Al(0 0 1)/Al3Ti(0 0 1) are calculated and compared by using first-principles density functional method. Three Al(1 1 1)/Al3Ti(1 1 2) models with different stacking sites (top-, bridge-, and center-sites), and two center-sited Al(0 0 1)/Al3Ti(0 0 1) models with different terminations (Al- and Al + Ti-terminations) are investigated. With the largest work of adhesion and smallest interface energy, the center-sited Al(1 1 1)/Al3Ti(1 1 2) is the most stable among the five models. The epitaxial stacking style is confirmed, and its adhesion work is larger than Al/Al(1 1 1). The heterogeneous nucleating mechanism of α-Al on Al3Ti(1 1 2) substrate can be interpreted as the perfect wetting, and stronger adhesion. Valence electron density and partial density of states (PDOS) are also analyzed. The interfacial bonding mainly comes from Al-Al metallic and Al-Ti covalent interactions.