Carbon Infused Aluminum Made by Flash: Higher Conductivity and Near Zero Creep

ABSTRACT

Three‐wire braids of pure aluminum were coated with ordinary carbon and flashed. Like the earlier experiments on copper, the aluminum braids show up to 20% increase in conductivity and near zero creep rate at temperatures close to the melting point. Like copper, the braids retained their shape when the temperature was increase to 900°C, 240°C above the melting point (nominally pure aluminum braid placed alongside curled up into a shapeless form). Similar results that were obtained in graphene infused copperwere explained by the evolution of a nanodomain network of predominantly sp ² carbon that which imaged by atom‐probe tomography and Raman. The Raman from the aluminum braids is exactly similar to that obtained for carbon‐infused copper. We rely on the high similarity of properties, and the Raman spectra, to infer that the aluminum wires too became infused with predominantly sp ² networks of carbon. In copper, these networks were shown to form domains in the form of rings about 2 nm in diameter. The high creep resistance means that aluminum transmission lines can be assembled without reinforcing cables that are deployed to prevent creep‐induced sag in cables made from nominally pure aluminum. The higher conductivity is an additional plus since it will reduce resistive losses. These experiments taken together raise the possibility that carbon networks can be infused generally into metals for the purpose of increasing their conductivity. Possible applications also include ceramics where the cathodes in lithium ion batteries and fuel cells are required to have mixed ionic and electronic conductivity.