Dynamic recrystallization of electroformed copper liners of shaped charges in high-strain-rate plastic deformation

The microstructures in the electroformed copper liners of shaped charges after the high-strain-rate plastic deformation were investigated by transmission electron microscopy (TEM). Meanwhile, the orientation distribution of the grains in the recovered slug was examined by the electron backscattering Kikuchi pattern (EBSP) technique. EBSP analysis illustrated that unlike the as-formed electro-formed copper liners of shaped charges the grain orientations in the recovered slug are distributed along randomly all the directions after undergoing heavy strain deformation at high-strain rate. Optical microscopy shows a typical recrystallization structure, and TEM examination reveals dislocation cells existed in the thin foil specimen. These results indicate that dynamic recovery and recrystallization occur during this plastic deformation process, and the associated deformation temperature is considered to be 0.6 times higher than the melting point of copper.