THE EFFECT OF ANNEALING ON SUPERDISLOCATION STRUCTURES AND ANTIPHASE-BOUNDARY ENERGIES IN FE3AL ALLOYS

The influence of annealing on [111] superdislocations introduced by pr ior deformation has been examined in several alloys based on Fe3Al, na mely a binary Fe-28% Al alloy, a ternary Fe-28% Al-5% Cr alloy, and a more complex alloy based on Fe-28% Al-5% Cr (where the compositions ar e in atomic percentages). The [111] superdislocations show signs of th e relaxation of the antiphase boundary (APE) between the partials, wit h the extent of relaxation varying considerably depending on the alloy considered. After longer anneals, particularly after high-temperature annealing, the [111] superdislocations react to produce [100] superdi slocations, with the APE between the new partials also providing evide nce of APE relaxation at longer times and higher temperatures. It is n ot possible to provide a complete explanation of the results obtained, which clearly depend sensitively on the alloying additions in the mat erial studied and the influence of these on such factors as order stab ility in the lattice and extent of solute segregation to the APB fault .