First-principles study of Ni/Ni3Al interface strengthening by alloying elements

The strengthening effects induced by alloying elements (Re, Ru, Cr, Co, Mo, W, Ta) on Ni/Ni3Al interface in single crystal Ni-based superalloys are investigated in terms of Griffith work using first-principles density functional theory. The best strengthening effect on Ni/Ni3Al interface can be attributed to Re, and the elements W and Ta appear to be less potent with Co having little effect. This sequence of creep-strengthening effect of alloying elements obtained from our calculations is consistent with relevant experimental observations. The calculated Griffith works for more elements of transition metals indicate that elements near the centre of the d block of the periodic table are more favorable for improving the rupture strength than those from the far west and far east of the transition metal block.