Abstract: The interfacial binding covalent bond density (CBD) and the local environmental total bond order (LTBO) of the Ni/Ni3Al interface with different lattice misfits (δ) were calculated by using first-principles discrete variation Xα method. It was found that the effects of lattice misfits on the electronic structures of incoherent Ni/Ni3Al interface were very obvious. On one hand, less than -0.6% negative lattice misfit can promote the binding strength of γ/ interface. On the other hand, the total bonding strength ofγ/ interface decreases with increasing δ. Therefore, the magnitude and sign of lattice misfit must be carefully controlled for balancing the high temperature creep strength of Ni-base single crystal superalloy and the structural stability ofγ/ interface when one designs a new Ni-base single crystal superalloy.

Key words: γ/ interface, lattice misfit, DV-Xα method, first-principles calculation