Influence of alloying elements on stacking fault energy in Ni and Ni-based alloy: A first-principles study

The study of the reliability of Ni-based alloys and their performance under high-temperature radiation environments is crucial for nuclear reactor application. The first-principles study has been utilized to investigate the effect of individual alloying elements (Cr, Fe, Mo, Nb) on the stacking fault energy (SFE) of pure Ni in order to understand their specific contribution in the superalloy Inconel 718 (IN718). The result shows that the addition of an alloying element in pure Ni reduces the SFE value with the most significant reduction seen in IN718 alloy. The role of individual alloying element in the reduction of the SFE in IN718 is conjectured. The DOS at EF F of all the elemental substitution configurations were also calculated and significant change is seen in the alloy IN718. Such reduction is due to the interrupted distribution of d-electrons and atomic bonding on the stacking fault planes, reflected in the SFE value.