The yield stress of binary Fe]Al alloys increases as
Al content increases, to a peak at the stoichiometric
composition; strength then decreases until B2 FeAl
forms. The strength of Fe Al is related to the pres- 3
ence of long-range DO -type order and the occur- 3
rence of two-phase alphaqDO regions as Al con- 3
tent exceeds 16 at.%. Although McKamey 23 at- w x
tributes strengthening to the interaction of superlattice
dislocations with thermally produced antiphase
boundaries and boundaries produced by superpartial
glide dislocations, this seems unlikely, based on earlier
work of Stoloff and Davies 16 on Cu Au. w x 3
Quenching of Fe Al alloys to produce partial B2-type 3
order results in a small decrease in flow stress.