ROOM TEMPERATURE MECHANICAL BEHAVIOR OF B2-ORDERED Fe_3Al SINGLE CRYSTALS

A detailed study of room temperature mechanical behavior of B2-ordered Fe3Alsingle crystals had been conducted. It was found that the yield strength, plastic elongation and work-hardening rate were changed with orientations. The highest ductility was measured from the specimen with the orientation near [110], where the plastic elongation is 42%. In contrast, at near [100] the plastic elongation is only 14.1%. The high work-hardening rate of the orientation near [110] was confirmed to be the results of superdislocation interaction, and the dissociation of two-fold superdislocations into single dislocations led to cross-slip, which resulted in further increase in elongation. The low work-hardening rate of near [211] was due to single active slip system and the superdislocations kept two-fold until the specimen was fractured.