Evaluation of strength and electrical conductivity of copper clad-AA6063 bimetallic composite wire after annealing treatment

Abstract

This study investigates the manufacturing of copper-AA6063 aluminum alloy composite wire and the effect of microstructural changes and metal-metal interface after annealing at 300 °C at different times on the strength and electrical conductivity. For fabrication of the composite wire, first AA6063 aluminum alloy wire was inserted inside an OFHC copper tube with a diameter of 6 mm. Afterward, a composite wire was produced using a cold drawing process in thirteen steps to a diameter of 1.5 mm. The tensile and microhardness tests used for evaluation of the composite wire's mechanical properties. Also, the light and scanning electron microscopes (SEM) used for microstructural characterization. The results showed that forming a region with a strain gradient at interface has a determinative effect on the strength and ductility of composite wire. The composite wire without annealing showed the highest strength, 278 ± 7 MPa. The annealing treatment result in strength reduction and negligible change in the electrical conductivity. The composite wire after annealing treatment for 30 and 60 min showed the highest electrical conductivity, 83 ± 1%IACS, and the highest elongation, 45 ± 4%, respectively.