Large tensile elongation behavior of extruded NiAl polycrystals with stoichiometric composition

The tensile deformation behavior and associated deformation microstructure of extruded NiAl polycrystals with stoichiometric composition were systematically investigated. Elongations over 200% and strain rate sensitivity indices near to 0.30 at high strain rate (10−1 s−1) were observed. This is attributed to the continuous dynamic re-crystallization, resulting in the formation of steady flow stress and a favorable value of strain rate sensitivity, and hence in large plastic elongation and high fracture resistance.