Enhancement of interfacial interaction and mechanical properties in aluminum matrix composites reinforced with CuO-coated graphene

Abstract

The interface in graphene-reinforced Al-based composites primarily facilitates the transfer of external loads from the matrix to the reinforcement. However, poor interface bonding between graphene and the Al matrix degrades the mechanical properties of the composites. In this work, reduced graphene oxide (rGO)@CuO/Al composites were prepared through surface modification and hot press sintering. The thermal reaction between CuO and Al at the interface promotes the formation of Al₂O₃ nano-layers on the C-Al interface, thereby enhancing the load transfer capability and the stability of the interface bonding. Additionally, the thermal-induced migration of oxygen atoms aids in the natural formation of Al₂O₃ inside the crystals. At the interface, the movement of copper atoms leads to a reaction with the Al matrix, resulting in the creation of CuAl₂, which inhibits the migration of grain boundaries. When the mass ratio of GO to CuO reaches 1:2, the ultimate tensile strength of the rGO@CuO/Al composite achieves 139 MPa, marking a 53 % improvement over that of the pure Al matrix and 124 % over that of the rGO/Al composite. The enhancement in mechanical properties is primarily attributed to the effective interface load transfer. This strong interface bonding caused by the thermite reaction provides new theoretical support for developing graphene/Al-based composites.