Improving Comprehensive Properties of Aluminum Conductor via Hierarchical Compositions and Microstructures

The development and deployment of aluminum conductor have been significantly hampered by the contradiction of yield strength, uniform elongation, and electrical conductivity. Herein, we successfully fabricated a pure aluminum (Al) clad aluminum alloy (AA) rod with hierarchical compositions and microstructures. The proposed pure Al clad AA rod showcases an optimized combination of yield strength, uniform elongation, and electrical conductivity, i.e., easing the restriction on improving yield strength, uniform elongation, and electrical conductivity. Compared to existing experiments, uniform elongation improved fourfold, while yield strength increased by 13% and electrical conductivity improved by 2% in terms of the international annealed copper standard (IACS). Microstructural characterizations and theoretical analyses revealed that the optimal performance of the Al clad AA arose from low-density low-angle grain boundaries (LAGBs) in the outer Al and high-density LAGBs with nanoscale precipitations in the inner AA. Our findings offer a compelling strategy for fabricating high-performance aluminum conductors, thereby laying a solid technical foundation for their wide application in power delivery systems.

Graphical Abstract