Simultaneously increasing the ductility and strength of ultra-fine-grained pure copper

Simultaneous increase of the ductility and strength of bulk ultra-fine-grained (UFG) Cu is achieved by introducing large amounts of deformation twins and high-angle grain boundaries via cryodrawing and cryorolling (red plots and image). Bulk UFG materials usually have high strength but disappointingly low ductility. Most previous attempts to enhance the ductility of single-phased UFG materials sacrificed their yield strength. This work provides a new approach for increasing ductility without sacrificing strength.