The DO3-type ordering in Fe-28Al and Fe-28Al-1.5Mn alloys are investigated
by TEM and XRD. The results show that Mn addition into DO3-ordered Fe3Al al
loy could decrease degree of ordering. Two major factors are considered to
have effect of Mn on ordering behaviour of the alloy: reducing grain size a
nd reducing antiphase domain size. The further investigation of deformed an
tiphase boundaries and slip lines in the alloy with Mn addition suggests th
at Mn could promote slip and cross slip in DO3 Fe3Al alloy during deformati
on. (C) 1999 Kluwer Academic Publishers.