Simultaneous enhancement of tensile strength and electrical conductivity of drawn Cu-20 wt.% Fe wire through intermediate annealing

The deformation of Cu-20 wt.% Fe alloy wires leads to a significant improvement in mechanical properties and a decrease in electrical conductivity. Simultaneous improvements in strength and conductivity were achieved by intermediate annealing of drawn Cu-20 wt.% Fe wires. As the annealing temperature increased, the strength of Cu-20 wt.% Fe alloy wire decreased monotonically, but the electrical conductivity first increased and then decreased, reaching its peak value after annealing at 500 °C. The decrease in strength is related to dislocation recovery and static recrystallization of Cu and Fe phases, and the increase in electrical conductivity mainly results from the aging precipitation of solid solution Fe. After annealing at 500 °C, there was no obvious recrystallization of Cu phase, and many of the nano-Fe particles precipitated from Cu matrix. An annealing temperature of 600 °C induced the recrystallization of Cu matrix and an increase in Fe solid solubility, resulting in a decrease in strength and electrical conductivity. Subsequently, the wires annealed at 500 °C were drawn to 2 mm. Compared with those of the continuously drawn Cu-20 wt.% Fe alloy wires, the deformation ability, strength, and electrical conductivity of Cu-20 wt.% Fe alloy wires subjected to intermediate annealing treatment are significantly greater. This is mainly related to the sufficient precipitation of Fe in Cu matrix and the strengthening of refined Fe fibers parallel to the drawing direction.