High electrical conductivity Al-Ag-Sc-Zr alloy with ultrafine grains processed by accumulative continuous extrusion

Abstract Continuous preparation of high-conductivity and high-strength aluminium alloy cable remains a challenge. Here we reveal the scientific significance of high electrical conductivity Al-Ag-Sc-Zr alloy with ultrafine grains prepared by novel processing technologies, the combination of rheo-extrusion and accumulative continuous extrusion forming. Attributed to the continuous dynamic recrystallization during rheo-extrusion, equiaxial microstructure and significantly refined grains (2.8±0.2 μm) were achieved. By means of partially replacing low conductive scandium and zirconium solute atoms with high conductive silver solute atoms, the processed alloy wires exhibit significant higher electrical conductivity (53.5±0.4 %IACS) than the Al-Sc-Zr alloy with similar atomic concentration of alloying elements. Appropriate mechanical properties were also obtained due to the similar solution strengthening effects of silver atoms to scandium and zirconium atoms. These results highlight the potential of this high electrical conductivity Al-Ag-Sc-Zr alloy and its novel processing route.