Strength–conductivity synergy in Cu–Cr alloy induced by rotary swaging: Microstructure reconstruction and interface optimization

Abstract

Cu–Cr alloys, owing to their excellent electrical conductivity and high strengthening potential, have broad applications in high-performance electrical engineering materials. In this study, a synergistic microstructural regulation strategy combining room-temperature rotary swaging (RS) with subsequent aging was proposed to construct a “load-bearing-conduction compatible” architecture, enabling simultaneous enhancement of strength and electrical conductivity in a Cu–Cr alloy (0.5 wt% Cr). The RS process induced pronounced axial grain elongation (aspect ratio ≈ 11) and promoted the enrichment and ordered arrangement of dislocations along microband boundaries, thereby forming a localized substructural network that integrates high-density strengthening with low-scattering conduction. Concurrently, RS accelerated Cr precipitation and facilitated a transition of precipitate-matrix interfaces from coherent to incoherent, significantly mitigating interfacial scattering. In addition, partial discontinuous dynamic recrystallization generated low-distortion grains, further optimizing electron migration pathways. As a synergistic outcome of these mechanisms, the yield strength increased from 404 MPa to 494 MPa, while the electrical conductivity improved from 71.3 % IACS to 82.2 % IACS. This dislocation-interface synergy overcomes the traditional trade-off between strength and conductivity, and, owing to the efficiency and scalability of the RS-aging process, offers a viable route for high-performance microstructural design and large-scale production of Cu-based alloys.