3. Benefits and limitations of superplasticity

3.1 Limits

These are mainly at three levels related to the material and the experimental deformation conditions: the microstructure of the material and its evolution, the deformation speed, and the temperature.

As already pointed out, the grain size of materials deformed under superplastic conditions must be small and remain relatively stable during deformation, which takes place at high temperatures. Obtaining such structures may require the use of complex thermomechanical processes, leading to high production costs. In the specific case of materials produced by powder metallurgy, this requires the use of ultra-fine powders and sintering procedures that prevent excessive grain growth. Here again, these requirements lead to a cost price for the materials that...