Enhancing tensile strength of Cu by introducing gradient microstructures via a simple torsion deformation

The influences of pre-torsion deformation on microstructure and tensile strength of commercial as-extruded Cu rods with cylindrical shape have been investigated in this study by twisting the rods to different numbers of revolutions. The results indicated that the pre-torsion can significantly enhance the tensile yield strength of the as-extruded Cu rods without changing their shape and size. The increase in tensile yield strength is mainly due to the gradient lamellar dislocation substructures (LDS) embedded in elongated fiber grains introduced by pre-torsion pure shear deformation.