Effect of deformation path-controlled metal flow and spatial particle arrangement on the strength-conductivity synergy of Al2O3/Cu composites

Al2O3-dispersed oxide-strengthened copper composites combine strengthening capability with relatively high electrical conductivity, making them promising for high-performance electrical applications. This study compares the effects of rotary swaging (RS), wire drawing (WD), and cold rolling (CR) at an equivalent strain (ε≈1). The results show that the deformation path governs composite performance by regulating particle spacing, dislocation structures, and grain morphology. Rotary swaging produced coupled radial compression, circumferential shear, and axial flow, resulting in axially elongated grains, dense dislocation tangles, and relatively favorable conductive pathways. WD favors fibrous boundaries and dislocation walls, while CR leads to higher distortion energy and dislocation cells. Although the average particle size remains ~10 nm, the effective obstacle spacing is path-dependent, resulting in varying Orowan strengthening efficiencies. Cold deformation increases the average hardness from 129.3 HV to 141.3–144.7 HV. RS achieved the best strength–conductivity balance, whereas CR showed the flattest hardness profile. These results identify rotary swaging as a more favorable path for retaining conductivity while achieving comparable strengthening and cross-sectional uniformity. These findings offer new insights for optimizing the cold processing of Al2O3/Cu composites.