Effects of thermomechanical processing on the microstructure and properties of Cu–0.3Cr–0.16 Mg alloy wires

Abstract

To overcome the inherent strength–conductivity trade-off in copper alloy wires, Cu–0.3Cr–0.16Mg​ alloy wires were developed using a multi-stage thermomechanical processing route. The influence of processing routes on precipitation behavior, deformation microstructure, and properties was examined. The observations show that the route involving pre-solution, hot forging, intermediate deformation, aging, and final achieves a balanced combination of tensile strength 790.6 MPa and conductivity 80.1% IACS. The main strengthening mechanisms are as follows. Hot forging and intermediate deformation introduce high-density dislocations and strain-concentrated zones, which provide heterogeneous nucleation points​ for precipitates. Preferential Mg segregation initiates the development of Mg-rich cores, which in turn induce Cr-rich shells, thereby establishing the Mg-core/Cr-shell configuration. This structure reduces the nucleation energy barrier of Cr-rich precipitates and facilitates their fine and dispersed distribution. Dispersed Cr-rich precipitates effectively pin dislocations and grain boundaries, promote dislocation accumulation and stabilize Brass, S and Copper deformation textures, achieving the synergistic effect of precipitation strengthening, deformation strengthening and texture strengthening. Meanwhile, sufficient solute depletion reduces electron scattering, enabling the alloy to retain high conductivity without compromising its strength. This study provides an effective processing route for microstructure regulation and property optimization of high-strength, high-conductivity Cu-Cr-Mg alloy wires.

The authors' abstract, as published at the source. Journal of Materials Research and Technology, 2026 · DOI ↗