THE ROLE OF CONTROLLED RECRYSTALLIZATION TREATMENTS ON DUCTILITY OF FE3AL ALLOYS

Careful heat treatments after mechanical processing can lead to optimi sed mechanical properties of Fe3Al-base intermetallics that is to high strength combined with maximum ductility. These heat treatments are s hown to lead to recovery of the dislocation structure introduced by pr ior working such that a fine subgrain structure is established. The su bgrain boundaries are constituted of networks of [100] dislocations th at are hence essentially immobile at room temperature. These boundarie s are effective obstacles to the [111] dislocations mobile during room temperature deformation and ensure that deformation is distributed un iformly throughout the grains. It is this homogeneous distribution of strain that is responsible for the good strength and ductility.