Substitutions (0-16 at%) of titanium for iron in Fe3Al-based alloys rapidly 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 have DO3 structure. DO3 and B2 antiphase domain size, lattice parameter and hardness increase with increasing titanium content of the alloy. The deformation mode changes from single (unit) bcc dislocation in binary alloys to two-fold superdislocation configuration in DO3Fe3Al-Ti alloys. Mechanical antiphase boundaries are generated by the movement of these imperfect configurations. All the. alloys exhibited cleavage tensile failure. The mechanical properties are correlated with the observed structural changes.