Fabrication of High–Strength and High–Electrical Conductive Cu–In Solid Solution Alloy Wires

Abstract

We attempted to fabricate high–strength and high–electrical conductive copper–indium (Cu–In) solid solution alloy wires. It was confirmed that the In solution in Cu matrix promoted an effective solid–solitoin strengthening without deteriorating the conductivity. When Cu–5 at.% In alloy was drawn severely, the wire contained high–dense deformation twins, and eventually formed ultra–fine grains with a size of 60 to 80 nm in average, which is attributed to lowering the stacking fault energy by solute In. The severely drawn Cu–5 at.% In alloy wire possessed an excellent combination of tensile strength of 1340 MPa, and conductivity of 24%IACS, which was comparable to that of competitive Cu–Be alloy wire with the combination of tensile strength and conductivity (approximately 1400 MPa, 22%IACS). The high strengthening in Cu–5 at.% In alloy wire by drawing was primarily due to grain refinement strengthening, and secondary to dislocation strengthening.