First-principles calculations on the stability of Al∕TiB2 interface

The atomic structure, adhesion, and interfacial energy of Al∕TiB2 interfaces were studied using first-principles calculations. The preferable interfacial atomic structure is that wherein the Al atoms continue the natural stacking sequence of the bulk TiB2. The interface adhesion for Ti-terminated interface is stronger than that for B-terminated interface. The structural stabilities of two interface terminations depend greatly on the Ti interfacial chemical potential. Calculation of the interfacial energies provides theoretical evidence for the hypernucleation and duplex nucleation grain refinement mechanisms.