The adhesion, stability, and electronic structure of γ-TiAl/VN interface: a first-principle study

The adhesion, stability, atomic bonding and electronic structure of gamma-TiAl (110)/VN (100) interface were studied by first-principle calculation. Five interface structures with different atom stacking sequences (top- and bridge-) were considered to examine the bonding nature. Results indicated that the preferred interfacial structure is that Al atom locates above the ceramic's metalloid atom, which has the largest ideal work of adhesion and the smallest interfacial energy. The top-site interface, where Al atom locates above the ceramic's metalloid atom, is characterized by a strong Al-N polar covalent bond, whereas the other top-side interface with Al atom above the metal atom exhibits an Al-V and V-Ti metal bond characteristics. The hybridization between Al-sp and N-sp orbitals is the main interaction that strengthens the interfacial adhesion.