The correlation between Re and P and their synergetic effect on the rupture strength of the γ-Ni/γ′-Ni3Al interface

A first-principles investigation on the synergetic effect of Re and P on Griffith rupture works of the γ-Ni/γ′-Ni3Al interface is performed. The calculated results indicate site preference of P at the γ/γ′ interface is not changed by Re-addition but P-induced embitterment can be inhibited even reversed by the addition of Re at the adjacent atomic layer of P. The correlative effect between P and Re at the γ/γ′ interface is also evaluated by a correlative energy function. It is found a strong repulsive interaction between P-doping and Re-addition is limited within a unit cell of γ or γ′ phase and is not profitable for the strengthening of the γ/γ′ interface. The electronic and geometric structures reveal a large interfacial separation and the depletion of electron densities in the interfacial region should be responsible for the potential inter-phase cleavage fracture site, and the deleterious effect of P can be attributed to a mutual influence of local elastic stain energy and atomic bonding energy in the doped system.