Achieving superior strength and conductivity for Al-Zr-Sc wires by coupling design of deformation and ageing

Abstract

Strength and electrical conductivity (EC) are key properties for heat-resistant Al-Zr-based alloy wires used as overhead transmission lines. Developing high-strength conductors with EC over 61.0% IACS has been a long-standing issue for heat-resistant Al conductive wires. In this work, a new design idea involving the coupling design of deformation and ageing was innovatively proposed to produce ultra-heat-resistant Al-0.2Zr-0.06Sc wires. The desired combination of high strength (195 ± 2 MPa) and good EC (61.2% IACS) was successfully achieved without annealing treatment. The strength residual rate of cold-drawn Al-0.2Zr-0.06Sc wire is as high as 94.0% after heat exposure of 280°C/1 h.

Keywords

• Al-Zr-Sc alloy
• cold drawing
• microstructure
• strength
• electrical conductivity