Effects of Composition and Temperature on Site Occupancies and Antisite Defects in B2-FeAl Ordered Phase: A Phase Field Study

The site occupancies and antisite defects play an important role in the physical and mechanical properties of intermetallic compound alloys. In this paper, the effects of Al concentration (c_Al) and temperature (T) on the change trend of site occupancies and antisite defects in B2-FeAl, which has attractive properties, were investigated by phase field method. The numerical results show that the increase of c_Al or the decrease of T can result in an acceleration of solute atoms segregation in matrix phase, and make site occupancies of Al and Fe as well as antisite Fe/Al reach equilibrium state earlier. Meanwhile, the increase of c_Al or the decrease of T can enhance the site occupancies of Fe and Al and reduce the two types of antisite defects. Furthermore, the theoretical results show that the change of c_Al and T is not able to change the main type of antisite defect in B2-FeAl ordered phase.