Abstract: Simultaneously improving the strength and electrical conductivity of conducting metallic materials is of great significance, but it still remains a key challenge as the two properties are often mutually exclusive. In this study, we demonstrate a “<111> oriented fibrous grains with ultra-high aspect ratio” strategy for breaking such a conflict in Cu wire, which relies on the distinctive spatial distribution of grain boundaries and the highly consistent hard orientation to play their respective roles in suffering loading and conducting, thereby enabling a separate optimization of both strength and electrical conductivity. Therefore, a processing route was designed, involving directional solidification followed by large drawing deformation, to successfully construct fibrous grains with an ultra-high aspect ratio in 596.7 and ultra-high <111> texture proportion over 97 %, which achieves Cu wire with a remarkable combination of yield strength in 482.3 MPa and electrical conductivity in 101.63 % IACS. Finally, the mechanisms for high strength and high electrical conductivity were quantitatively discussed.

Key words: Strength, Electrical conductivity, Cu wire, Grain, Directional solidification