Development of ultra-high-strength Al-Mg-Si conductor alloys with copper addition via scalable thermomechanical processes

Abstract

An ultra-high strength Al-Mg-Si conductor alloy was developed using the addition of 0.4 wt.% Cu. Using scalable thermomechanical processes, the Cu addition resulted in a substantial 37% increase in the ultimate tensile strength (UTS) with a slight 4.5% decrease in the electrical conductivity (EC), achieving 500 MPa UTS and 49% IACS EC. This breakthrough achievement holds promise for replacing the steel core traditionally used in aluminum conductor steel reinforced (ACSR) cables with high-performance Al alloys. The significant increase in the strength of the developed alloy was attributed to the formation of coherent Cu-containing β" precursors during preaging, which exhibited higher dissolution resistance during wire drawing, thereby remaining highly dispersed in the matrix after 92% area reduction.