EFFECT OF TITANIUM SUBSTITUTION ON THE STRUCTURE AND PROPERTIES OF FE3AL-BASED INTERMETALLIC ALLOYS

Substitutions (0-16 at%) of titanium for iron in Fe3Al-based alloys ra pidly solidified by chili-block melt-spinning stabilize the DO3 and B2 ordered structures. Rapid solidification results in total suppression of DO3 order in binary alloys, whereas alloys containing titanium hav e DO3 structure. DO3 and B2 antiphase domain size, lattice parameter a nd hardness increase with increasing titanium content of the alloy. Th e deformation mode changes from single (unit) bcc dislocation in binar y alloys to two-fold superdislocation configuration in DO3Fe3Al-Ti all oys. Mechanical antiphase boundaries are generated by the movement of these imperfect configurations. All the. alloys exhibited cleavage ten sile failure. The mechanical properties are correlated with the observ ed structural changes.