Creep behaviour of iron–aluminium–chromium intermetallics strengthened by nano-sized oxide particles

The creep behaviour of some oxide-dispersion-hardened Fe–Al–Cr iron aluminides has been examined at 700–750 °C and compared with similar dispersion-hardened steels and commercial Fe–Cr alloys. Very fine oxide particles form during material processing, which are generally fcc Y2O3 phase with a thin disk morphology, and partially coherent with the ordered FeAl matrix. The materials show excellent creep strength at the tested temperatures which may be related to the oxide particles being barriers opposing dislocation motion. Precise details of dislocation–particle interactions are not clear, but it is suggested that the fine particles are cut relatively easily by the dislocations.