Using severe plastic deformation for grain refinement and superplasticity

The grain size of many metals may be reduced to the submicrometer or nanometer level using various procedures incorporating the application of severe plastic deformation. This paper examines the procedure and potential of equal-channel angular pressing (ECAP) in which a material is pressed through a die and a high strain is imposed without any change in the cross sectional dimensions of the workpiece. Various factors influence the ultrafine grains attained using ECAP and examples are presented showing the application of ECAP in fabricating materials exhibiting high strain rate superplasticity and rapid forming capabilities