Using deformation mechanism maps to depict flow processes in superplastic ultrafine-grained materials

Deformation mechanism maps are a very useful tool for displaying deformation mechanisms as a function of the three fundamental parameters of high temperature flow: the applied stress, the testing temperature and the grain size of the material. These maps are used extensively in the field of high temperature creep but there has been very little use with ultrafine-grained (UFG) metals. This article reviews the principles of deformation mechanism maps, presents examples of maps for some representative metals processed by equal-channel angular pressing or high-pressure torsion and then describes a simple procedure for constructing maps for UFG materials.This work was supported in part by the National Science Foundation of the United States under Grant No. DMR-0855009 and in part by the European Research Council under ERC Grant Agreement No. 267464-SPDMETALS