Dislocation processes in Fe3Al investigated by transmission electron, scanning force and optical microscopy

The mobility of dislocations in Fe3Al has been investigated by four complem entary methods: (1) In-situ transmission electron microscopy (TEM) of the d islocation motion in thin single crystal foils; (2) TEM of dislocation conf igurations after deformation of bulk single crystals; (3) atomic force micr oscopy of slip traces on deformed bulk single crystals; and (4) In-situ opt ical microscopy of slip traces on bulk single crystals during plastic defor mation. These investigations yield information on: activated glide planes, Burgers vectors, mode of glide (concentrated vs, finely distributed, smooth vs. jerky) and the specific energy of antiphase boundaries. The variations of the macroscopic plastic behavior and of the modes of glide of Fe3Al in the investigated temperature range of 300-973 K are discussed on the basis of the observed dislocation mechanisms. (C) 1998 Elsevier Science S.A. All rights reserved.