First-principles study of Ni/Ni3Al interface doped with Re, Ta and W

Abstract

The strengthening effects of (0 0 1) Ni/Ni3Al interface alloying with Re, Ta and W in Ni-based single crystal superalloys were studied using first-principles density functional theory. By placing alloying elements on (0 0 1) Ni/Ni3Al interface, the substitution formation energy, the Griffith work, the generalized stacking fault energies, the partial density of states and the charge density difference were all calculated. It is figured out that Re, Ta and W atoms prefer to substitute Al positions of γ' phase. It is consistent with the experimental results. The strengthening effect of Re atom on (0 0 1) Ni/Ni3Al interface is stronger than that of Ta and W atoms addition. The order of strengthening effects of Re, Ta and W atoms from our calculations is consistent with relevant experimental observations. By analyzing the charge density difference and the partial density of states, our results show that the hybridization between Re atom and the nearest neighbor Ni atoms is the strongest, which is conducive to explore the essential reason for the different strengthening effects of alloying atoms at electronic level.