Study of the Thermal Stability of the Structure and Mechanical Properties of Composite Wires from Microalloyed Aluminum Alloys

The thermal stability of a composite wire made of microalloyed aluminum alloys Al–Zr–(Sc, Hf) is investigated. The wire is produced by the combined drawing of a copper-coated aluminum alloy. The effect of annealing on the mechanical properties of the composite conductive aluminum wire is studied. It is shown that the process of decomposition of the solid solution upon the annealing of composite wires occurs in two stages, due to the separate precipitation of Al3Zr particles at “low” temperatures and the precipitation of Al3(Sc, Hf) particles at “high” annealing temperatures. Mechanical tensile tests show that annealing at 500°C for 30 minutes reduces the strength and increases the ductility of the wire by up to 10%. After annealing, a homogeneous fine-grained structure is formed in the wire, and increased hardness and strength of the samples is observed due to the release of Al3(Sc, Hf) particles.