Cooperative Enhancement of Strength and Ductility in Metallic Materials: the Role of Local Stress/strain Evolution on the Plastic Flow Behavior

Simultaneous enhancement of strength and ductility is one of the eternal topics for the community of metallic materials. The heterostructure architecture, e. g. layered structure, is one of the potential methods to evade the strength-ductility trade-off dilemma in recent years. However, there is still a lack of a deeper understanding to excellent strength-ductility combinations. In the present study, we focused on the local stress, which drives local plastic deformation. The local represents the affected scale of the stress. The evolution processes of local stress/strain upon loading of typical model materials of Ti/Ti, Ti/Al, and Al/Al layered metals (LMs) were quantitatively characterized by in situ electron microscope, synchrotron X-ray diffraction, and neutron diffraction. We found that the deformation characteristics were closely associated with the local stress/strain evolution process, and highlighted the key role of local stress/strain in revealing the deformation mechanisms This work therefore may open a new route to design new metallic materials through the tailoring of local stress/strain evolution.