Structure and Properties of Ordered Intermetallics Based on the Fe-Al System.

Abstract

Recent work on the ordered Fe-AI based intermetallics (B2-FeAl and D03-Fe3Al) for potentia] high temperature applications is reviewed with emphasis on improvements in mechanical properties achievable by processing and compositional control. Constitution and microstructure as well as the role of crystalline defects, including vacancies, dislocations, tubes, antiphase boundaries and grain boundaries are discussed. The influence and behaviour of these defects with respect to strength, work hardening, ductility and fracture are analysed. Proposed mechanisms for deformation and recent investigations on creep and fatigue of these materials are also reviewed. Current literature on ternary additions, multi-phase alloys and non-equilibrium processing is discussed.