Elevated temperature deformation and dynamic strain aging in polycrystalline RuAl alloys

The flow behavior and dislocation substructure in RuAl intermetallics have been studied in the temperature range of 298–1173 K. A number of characteristics indicative of dynamic strain aging are observed: serrated flow, flow stress plateau, maxima in the rate of work-hardening and minima in strain-rate sensitivity. Static aging experiments reveal that the serrated flow is associated with the presence of solute atoms that are mobile at TTm≈0.3. Dislocation substructures following elevated temperature deformation consisted of <100> and <110> dislocations present in the form of tangles and within cell walls. Typical features of the flow behavior of these intermetallic alloys are compared with those of NiAl, another B2 intermetallic that exhibits dynamic strain aging. Mechanisms for the DSA phenomenon in RuAl are proposed.