The weak-beam technique was used to observe two- and four-fold dissociation in Fe-Al alloys with compositions between 26 and 36at%Al, with B2-type and with DO3-type long-range order. From the orientation versus separation curves, the antiphase boundary energies were determined as a function of composition for both types of order. The nearest-neighbour antiphase boundary energies for 26.9, 27.8 and 28.3at%Al alloys were 68, 76 and 79mJ/m2, respectively. The next-nearest neighbour antiphase boundary energies for 26.9, 27.8 and 28.3at%Al alloys were 72, 53 and 64mJ/m2, respectively.

Antiphase Boundary Energies in Iron-Aluminium Alloys. R.C.Crawford, I.L.F.Ray: Philosophical Magazine, 1977, 35[3], 549-65