Thermal Stability of the High Strength High Conductivity Cu–Nb, Cu–V, and Cu–Fe Nanostructured Microcomposite Wires

The anomalous increase of the mechanical strength in copper matrix FCC-BCC composite materials caused by the specific nanoscaled microstructure formed by the heavy plastic deformation is associated mainly with the nature of the interface boundary areas. The differences in the nature of the interface areas in the Cu-Nb, Cu-V, and Cu-Fe have been discussed in connection with the parameters of crystallographic structure of three BCC elements (Nb, V, Fe). The nanostructured Cu-Nb, Cu-V, and Cu-Fe experimental high strength, high conductivity wires have been fabricated by the similar technological routes. The tensile strength and electrical conductivity for Cu-Nb, Cu-V, and Cu-Fe microcomposite wires are presented. The stability of the filamentary nanoscaled microstructure created by the large plastic deformation is investigated. We demonstrate that it is possible to maintain mechanical strength higher than 400 MPa after long time heat treatment between 250°C and 400°C.