Development of High–Strength Solid–Solution Cu–Mg Alloy Suitable for Small Terminals

Abstract

In recent years, demands for miniaturization and multi–polarization of automotive connectors have grown, along with increasing needs for highly integrated electronic devices in vehicles. For this reason, copper materials for connectors are required to have high strength, high electrical conductivity, high stress relaxation resistance, and excellent bending workability. Among various solid solution strengthening copper alloys, Cu–Mg alloy was found to exhibit excellent balance between strength, electrical conductivity, stress relaxation resistance, and bending workability. With Cu–Mg alloy rolled at 98.4%, the rolling texture formed by heavy cold rolling was deliberately utilized, and the optimum characteristics for small terminals；tensile strength of 1016 MPa, electrical conductivity of 40% IACS, residual stress rate of 71%, and bending workability of R/t=0；was obtained.