The influence of Cr additions on the positive temperature dependence of the flow stress and on the antiphase boundary energy of Fe3Al was investigated. Single crystals of binary Fe-28at%Al and ternary Fe-28Al-6at%Cr were deformed in uniaxial compression between room temperature and 1273K. The dislocation arrangement and the dissociation of super-dislocations were studied by transmission electron microscopy, using the weak-beam technique. The operative slip systems were considered on the basis of direct measurements of the antiphase boundary energies. Three types of fault energy of super-dislocations were analyzed up to 1003K as a function of Cr content: the nearest-neighbor energy in the slip plane, the next-nearest neighbor energy in the slip plane and the nearest-neighbor energy in the cross-slip plane. The nearest-neighbour antiphase boundary energies for the Fe-28at%Al and Fe-28Al-6at%Cr alloys were 73 and 78mJ/m2, respectively. The next-nearest neighbour antiphase boundary energies for the Fe-28at%Al and Fe-28Al-6at%Cr alloys were 80 and 100mJ/m2, respectively.

Superdislocations and Antiphase Boundary Energies in Deformed Fe3Al Single Crystals with Chromium. F.Král, P.Schwander, G.Kostorz: Acta Materialia, 1997, 45[2], 675-82