Analysis of element-content effects on equilibrium segregation at γ/γ′ interface in Ni-base superalloys using the cluster variation method

Effects of alloying element-content on equilibrium segregation at and adjacent to the (100) γ/γ′ interface in Ni-base superalloys were analyzed by using the cluster variation method incorporated with tetrahedron approximation and the phenomenological Lennard–Jones potential. Results suggest that Al-site occupiers in the γ′ phase such as Mo, Re and W were enriched near the interface on the side of the γ phase. On the other hand, Co, which prefers to substitute for Ni site, exhibited minimal segregation in the γ phase. The enrichment of the refractory elements such as Mo, Re and W around the interface was moderated, because Co addition slightly diluted refractory elements throughout the γ phase.