Electromagnetically cast Al-0.5 wt. % Fe alloy as a core material for the co-extruded copper-clad aluminium wire

In this study, the electromagnetically cast Al-0.5 wt. % Fe alloy was used as a core material for the copper-clad aluminium wire with the copper grade M² outer sleeve. The choice of core material decreased the risk of premature copper-clad aluminium wire failure due to higher, compared to pure Al, mechanical strength and thermal stability. The mechanical bonding of the bimetallic wire was conducted via joint cold drawing. The produced copper-clad aluminium wire with the 37% copper fraction in the cross-section is characterized by good adhesion of the Al and Cu layers. No intermetallic particles were observed on the Al-Cu interface in neither hard-drawn nor annealed state. Hard-drawn copper-clad aluminium wire is characterized by high mechanical strength and electrical conductivity while possessing an acceptable level of ductility. Subsequent to cold drawing annealing at 300 °C for 1h led to decrease of yield strength and ultimate tensile strength, as well as to increase in ductility and electrical conductivity. However, in both hard-drawn and annealed states copper-clad aluminium wire is characterized by the properties that lay within and even exceed the values recommended by international standards. Evaluation of the copper-clad aluminium wire ultimate tensile strength according to the rule of mixtures showed the importance of surface preparation on all the stages of the wire production.