Effect of thermo-mechanical age hardening on the strength and electrical conductivity of Copper-AA6063 bimetallic wire

This research explored the impact of age-hardening treatment on the mechanical response and electrical resistivity of copper-clad AA6063 alloy bimetallic wire, with a focus on microstructural analysis and interface characterization. In this study, AA6063 alloy wire was inserted into an oxygen-free high conductivity copper tube, and a bimetallic wire was fabricated through a wire drawing process that reduced the cross-sectional area in 13 stages. The bimetallic wire underwent a series of thermo-mechanical treatments, including various combinations of wire drawing, solution heat treatment, and artificial aging. The findings revealed that applying solution heat treatment prior to wire drawing, followed by artificial aging after drawing, produced a clean interface free of intermetallic compounds. This processing approach resulted in a Cu-Al bimetallic wire with a strength of 286 MPa and an electrical conductivity of 80 % IACS. Furthermore, the electrical conductivity-to-density ratio reached 13 % IACS/(g·cm⁻³), representing a 16 % improvement over oxygen-free high conductivity copper.