Characterization and Mechanism Studies of Carbon incorporation into Al alloys

The incorporation of C nanostructures into Al alloys, such as Al 6061 and Al 1350, has the potential to further improve the mechanical, electrical and anti-corrosion properties of these alloys. We report on an electrocharging-assisted method to incorporate up to 10.0 wt.{\%} C into the crystal structure of Al alloys to form a new material ``Al Covetics''. In this method, a DC current is applied to molten Al metal containing activated C particles. The current facilitates ionization of the C atoms followed by polymerization of the C structures and formation of graphitic chains and ribbons along preferred directions of the Al lattice. Raman mapping results indicate uniform C distribution over the surface in the Covetics. XPS carbon peak decompositions show \textit{sp2} and \textit{sp3} bonding from C structures and carbide bonding from Al-C bonds. TEM EELS spectra present a sharp C-K edge at 284eV, which further confirms the presence of \textit{sp2} bonding in Covetics. The possible mechanism of Covetics conversion is similar to ``electromigration in a plasma''. The current attracts charged Al and C atoms and the reaction takes place. The dependence of the mechanical, electrical and structural properties of Al covetics on carbon content from 3 to 10 wt. {\%} will be presented.