Microstructure and properties development of copper during severe plastic deformation

Annealed pure copper was subjected to equal-channel angular pressing (ECAP) to produce a nanocrystalline (NC) structure. The microstructure and the development of the mechanical properties of copper under severe plastic deformation (SPD) were studied. The structural changes and the properties due to heat treatment and the different loading methods of NC copper were analyzed and compared. The results show that the heat treatment and the hard cyclic deformation in the viscoplastic regime influence the properties of NC copper to a great extent. The ultimate tensile strength and the microhardness of NC copper decrease while heat-treated NC copper acquires enhanced true tensile properties after hard cyclic deformation in the viscoplastic regime.