UNSTEADY AND STEADY-STATE REGIONS OF SUPERPLASTIC FLOW

The time required for the attainment of steady state superplastic flow is predicted and experimentally verified. The effect of strain rate, grain size and test temperature on the shape of the true stress-true strain curve (up to and just beyond the onset of steady state flow) is considered. The strain-rate sensitivity of steady state deformation, elongation to fracture and post-deformation microstructures observed are shown to be consistent with earlier results. © 1979.