Superplasticity of stoichiometric NiAl with large grains

Stoichiometric polycrystalline NiAl exhibits superplasticity under a range of initial strain rates from 1.67 x 10-4 to 1.67 x 10-2 s-1 at 1000°C and 1100°C. The maximum elongation of 210% with the strain rate sensitivity index m = 0.34 is obtained at 1100°C under an initial strain rate of 1.67 x 10-3 s-1. Dynamic recovery and recrystallization resulting from simultaneous operation of glide and climb of dislocations taking place during deforming at high temperature is suggested to be the superplastic mechanism for stoichiometric polycrystalline NiAl.