The effect of Cr additions upon the positive temperature dependence of the flow stress, and upon antiphase boundary energies, was investigated. Monocrystals of binary Fe-28Al and tertiary Fe-28Al-6at%Cr alloys were deformed in uniaxial compression between room temperature and 1273K. The dislocation arrangements, and the dissociation of super-dislocations, were studied by means of transmission electron microscopy in the weak-beam mode. The operating slip systems were considered with regard to direct measurements of the antiphase boundary energies. Three types of super-dislocation fault energies were analyzed as a function of temperatures of up to 1003K, and as a function of the Cr concentration. These were the nearest-neighbor antiphase boundary energy in the slip plane, the next-nearest neighbor antiphase boundary energy in the slip plane and the nearest-neighbor antiphase boundary energy in the cross-slip plane. The calculated results were in good agreement with experimental data.

F.Král, P.Schwander, G.Kostorz: Acta Materialia, 1997, 45[2], 675-82