Grain size dependence of tensile properties in ultrafine-grained Cu with nanoscale twins

We investigate the grain size dependence of tensile behaviors of nanotwinned Cu with fixed twin thickness. With an increased grain size, ductility and work hardening of nanotwinned Cu are effectively promoted, but strength is not sacrificed to any notable degree. This may be attributed to the highly anisotropic plastic deformation of nanoscale twins.