Dynamic restoration mechanism of a Fe₃Al based alloy during elevated temperature deformation

By TEM and metallographic examination, we found that dynamic recovery and following continuous recrystallization, which connects with the elevated temperature ductility, takes place in a Fe₃Al based alloy during elevated temperature deformation. Dynamic restoration consists of the following process: (1) by climbing or cross-slipping glide dislocations change into dislocation arrays, (2) the dislocation array attracts lattice dislocations, (3) with increasing dislocation density, a non-equilibrium subboundary forms, which is easy to migrate, slide or rotate under external force, and (4) when the misorientation angle of the subboundary increases to a critical value, the subboundary changes into a grain boundary with continuous misfit. By relaxation, the boundary then changes into a grain boundary consisting of periodical structure units.