TiB₂(Ti)//Al interfacial energy is significantly reduced when xy strain is removed.

TiB₂(Ti)//Al₃Ti interfacial energies are calculated for the first time.

On the TiB₂(Ti) substrate, Al forms a more stable interface than Al₃Ti.

On the TiB₂(B) substrate, thin layers of Al₃Ti form a more stable interface than Al.

Aluminium nucleation is proposed to occur directly off Ti-terminated TiB₂.