Microscopic phase field simulation on the solute segregation and composition evolution of heterointerfaces in Ni-Al-V alloy

Based on the microscopic phase field model, the precipitation process of Ni-Al-V alloy was simulated. The composition distribution and the evolution of order-disordering interface and ordered heterointerface formed between DO ₂₂ and L1 ₂ phase were studied. The results show that the degree and the preference of segregation or the depletion of alloying elements are related with the atomic structure of interfaces. Ni and Al segregate, V depletes at the order-disorder interface formed between DO ₂₂ and disorder phases. Ni and Al deplete, V segregates at the order-disorder interface formed between L1 ₂ and disorder phases. At the ordered heterointerfaces, V segregates at the DO ₂₂ side of the interface but depletes at the L1 ₂ side of the interface, Al depletes at the DO ₂₂ side of the interface but segregates at the L1 ₂ side of the interface. The distribution of Ni at the ordered heterointerface is related with the formation process of the interface. The preferences of segregation or the depletion of alloy elements remain unchanged, but the distribution of alloy elements becomes sharp during the evolution of interface.