Superplasticity

Abstract

Some materials are capable of undergoing large tensile extension of the order of hundreds and even thousands of percent. These superplastic materials are strong and ductile at low temperatures and exhibit high plasticity at high temperatures. They deform without showing necking. The large plastic extension enables fabrication into intricate shapes by simple forming process which is quite important in the case of ceramics where usually machining is a difficult process. A much investigated ceramics is the Y-TZP which can show an extension over ~100%. Structural considerations are grain size, grain boundaries and cavitation. Fine-grained ceramics can be superplastic at elevated temperatures.