Interface stability of γ/γ'/γ" formed by V atom grain boundary diffusion and segregation in Ni-Al-V alloys

In Ni-Al-V alloys, the coherency Phase Boundary (PB) between D0₂₂-γ"(Ni₃V) precipitate phase and matrix, as well as L1₂-γ′(Ni₃Al) phase, plays a significant role in the material's overall properties and performance. Up to now, the integrated interaction between the three phases remains void, since a comprehensive study of their coherency PBs is urgently needed. In this work, the diffusion and segregation behaviors of V atoms during the formation process of D0₂₂ phase, as well as the interaction of PBs between D0₂₂-γ"(Ni₃V) initial crystal core, FCC-matrix, and L1₂-γ′(Ni₃Al) phase, are investigated using first-principles combined with microscopic phase-field. We also calculated the differences in PBs stability for different orientation relationships and analyzed the relationship between atomic arrangement PBs stability from the perspective of V atom interaction with Ni and Al atoms. The results showed that V atoms tended to enrich at $Ni/{Ni}_{3}Al$ PBs, thereby forming the initial core of Ni₃V precipitate phase. And from the perspective of energy and electronic structure, the nucleus tends to maintain a $Ni\left(100\right)/{Ni}_{3}V\left(100\right)/{Ni}_{3}Al\left(100\right)$ orientation relationship with matrix and γ"(Ni₃V). D0₂₂-γ"(Ni₃V) precipitation phase and the new PBs tended to preferentially grow on $Ni\left(001\right)/{Ni}_{3}V\left(001\right)$ during nucleation. This work could be beneficial for understanding the initial movement of V atoms and the behaviors of PBs during the early stage of D0₂₂-γ"(Ni₃V) formation in Ni-based alloys and designing the nickel-based alloys with comprehensively desired performances.