The relationship between stress and strain rate is often sigmoidal in superplastic materials, with a low strain rate sensitivity at low and high strain rates (regions I and III, respectively) and a high strain rate sensitivity at intermediate strain rates (region II) where the material exhibits optimal superplasticity This relationship is examined in detail, with reference both to the conflicting results reported for the Zn-22 pct Al eutectoid alloy and to the significance of the three regions of flow

The mechanical properties of superplastic materials

A review of multi-physical fields induced phenomena and effects in spark plasma sintering: Fundamentals and applications

Stress-enhanced grain growth in a nanocrystalline material by molecular-dynamics simulation

On the mechanism of strain-enhanced grain growth during superplastic deformation

The superplastic behavior of the composite Y-TZP/Al{sub 2}O{sub 3} (20 wt%) in uniaxial tension has been evaluated. Large elongation (>200%) indicated superplasticity. The stress exponent and activation energy of thee composite were found to be the same order with those of Y-TZP. The flow behavior of the composite containing Al{sub 2}O{sub 3} grains could be described by a rheological model as a non-Newtonian flow modified by the second-phase grains. The cavitation damage and the creep crack growth could be reduced by keeping the strain rate low enough that a specimen elongated 100% at elevated temperature maintained a strength of 1,800 MPa at room temperature.

M.A Clark

Papers

Deformation enhanced grain growth in a superplastic Sn-1% Bi alloy