Recent advances and future directions in superplasticity

Superplasticity is generally associated with fine grains, grain boundary sliding, accommodation, high tensile ductility and high strain-rate sensitivity at: elevated temperatures. This paper reviews some of the recent important findings in very fine-grained superplastic materials, including the areas of high-strain-rate superplasticity in aluminum based materials and of low-temperature superplasticity in magnesium based materials. Deformation mechanism maps are shown to be powerful methods for predicting the conditions where high-strain-rate superplasticity and/or low-temperature superplasticity can be expected. Ultrafine grained materials, processed economically, remain an important future objective in achieving high-strain-rate superplasticity and/or low-temperature superplasticity, which have considerable promise for net-shape isothermal forming of sheet and bulk components in industry scale.