The partitioning behavior of dual solutes at the antiphase domain boundary in the B2 intermetallic: A microscopic phase-field study

The partitioning behavior of dual solutes at the antiphase domain boundary (APDB) in B2 intermetallic is studied by establishing a ternary BCC phase-field model of atomic-resolution. The influence factors doping concentration of the third alloying solute, temperature and lattice misfit strain are considered. The elemental co-distribution caused by the partitioning behavior is characterized by the topographic map of solute and micro deviation of concentration. Theoretical results reveal that the co-distribution is Ni segregation coupled with Al depletion and Fe segregation. At the microscopic level, the micro deviation level is confirmed to be strongly dependent on the magnitudes of Ni concentration, temperature and lattice misfit. At the atomic level, the micro deviation is heterogeneous. The mechanism, regular dependence, and heterogeneity of the elemental partitioning under three factors are revealed from the viewpoint of energy. This work provides a new perspective on understanding the origin of the partitioning behavior of constituent elements at the APDB in B2 intermetallics and will be beneficial to evaluate elemental distribution-APDB-properties in future FeAl-base superalloys design with multi alloying additions and the interface engineering. •A ternary microscopic phase-field model of A2-B2 phase transition is established.•The solute partitioning behavior of Ni segregation is coupled with Al depletion.•The partitioning of Ni, Al and Fe at the APDB is decreased by raising temperature.•Raising lattice misfit/Ni content intensifies Ni, Al and Fe deviations at the APDB.•Extreme distributions of Ni and Al occur in directions along the APDB.