Mechanical properties and fracture of nanocopper by severe plastic deformations

The development of the nanostructure in commercial pure copper, its strength and ductility after severe plastic deformation (SPD) with the technology of equal-channel angular pressing (ECAP) are analysed. It is shown that both the strength and ductility can be increased simultaneously by SPD. The final grain size decreased from the initial 50 m to 100-300 nm after 10 passes of ECAP. The increase of the ductility and strength, caused by SPD, is explained by strong grain refinement and by the dynamic equilibrium of weakening and strengthening.