Simulation of ordered domain interfaces formed between L1₂ phases in Ni-Al-V alloy using microscopic phase field model

Microscopic phase-field model was used to simulate the ordered domain interfaces formed between L1₂ phases (Ni₃Al) in Ni-Al-V alloy. The interface structure and the behavior of atoms at the interfaces were investigated using the occupation probability of atoms. The results show that there are three kinds of stable translation domain interfaces and two kinds of transition interfaces formed between L1₂ phases. The migration ability of interface is related to its structure: as the interface consisted of two Ni atom planes and (100) of a L1₂ phase and (200) of another L1₂ phase are in alignment or (100) and (100) in alignment the interface can migrate and formed a transition interface during the process of migration, but the structure of interface is invariant before and after the migration; as the interface consisted of one Ni atom plane and (100) and (200) are in alignment the interface can not migrate. The elements of alloy have different preferences of segregation or depletion at different interfaces, Al is depleted at all interfaces but V segregated, Ni is depleted at the migratory interfaces but segregated at the immovable interface. The degrees of segregation and depletion are also different at different interfaces.