The effect of graphene concentration on mechanical properties of electrodeposited Al-Graphene composite coating

Abstract

To enhance the surface hardness and strength of aluminum alloys and achieve low-temperature synthesis of aluminum-graphene composite materials, Al-Graphene composite coatings are electrodeposited on the 7075-aluminum alloy substrate from organic solvent solution system at 25 ℃ containing different graphene concentration. The morphology, microstructure and mechanical properties of Al-Graphene composite coating were characterized and reconnoitered. Al-Graphene composite coatings exhibit improved performance significantly. Under the optimal graphene concentration of 7 g L⁻¹, Al-Graphene shows 5.1-times increase in hardness in comparison with pure Al coating. The elastic modulus has the peak value of 84.4 GPa for Al-Graphene containing 10.64 wt% graphene, which has an increment of 66.2 % compared with pure Al coating. These put down to the remarkable mechanical property of graphene. Moreover, the content and distribution of graphene play a key role in the mechanical properties of Al-Graphene. The alternating well-dispersed graphene and reduced metal layer, simultaneously keep appropriate thickness of reduced metal layer is able to achieve the optimal comprehensive mechanical property, which exhibits promising application potential in aircraft skins, automotive components, and related fields.