instability induced by incoherent twin boundary in nanotwinned copper
1. Strain hardening and softening in nanotwinned Cu:
Nanotwinned Cu foils with about 99% coherent twin boundaries (TBs) among all the boundaries were made. These coherent
TBs, with an average spacing of 25 nm, were engineered approximately parallel to foil surfaces. Low plane-strain deformation
enhances the hardness by refining microstructure and introducing dislocations. High plane-strain deformation results in crystallographic
lattice rotation and reaction between dislocations and coherent TBs, and induces incoherent TBs, thus twin coarsening and