Fabrication of a novel high-strength and high-conductivity copper-clad aluminum composite wire

The present study is focused on characterizing the microstructure, mechanical properties, and electrical resistance of a novel copper-clad aluminum composite wire. In this regard, the extrusion and wire drawing processes have been used to produce the composite wire. After every deformation step, intermediate annealing was performed at a temperature of 300 °C for 30 min. The microstructure has been investigated using an optical microscope (OM) and a scanning electron microscope (SEM) equipped with energy dispersive spectroscopy (EDS). Besides, microhardness and tensile tests were utilized to determine mechanical properties. Also, a micro-ohmmeter was employed to measure the electrical resistance. The findings indicated that the composite wire's interface was uniform and homogeneous without evidence of thick and continuous intermetallic compounds (IMCs). A comparison between oxygen-free high conductivity (OFHC) copper and composite wire demonstrated that applying a reduction ratio to 99.6% on the composite wire resulted in electrical conductivity higher than 66.8% IACS. Also, the ultimate tensile and yield strengths were increased 37% and 183%, respectively. The strength improvement was attributed to the fine particle distribution in the aluminum alloy core and the residual stress caused by the different elastic properties of the two materials during deformation.