A high strength and high electrical conductivity graphene/Cu composite with good high-temperature stability

Graphene/Cu (Gr/Cu) composites have promising applications in many industrial fields. However, it is still a challenge to prepare Gr/Cu composites with excellent mechanical-electrical synergy. In this paper, we prepared Gr/Cu composites with high strength and high electrical conductivity simultaneously by electrodeposition, sintering, and cold rolling. The cold-rolled Gr/Cu composite displays a high yield strength of 485.1 MPa and high electrical conductivity of 94.1% IACS. The Gr/Cu composite not only exhibits excellent mechanical-electrical synergy but also shows better high-temperature stability compared to pure copper. After annealing at 260 °C for 10 min, the yield strength of the Gr/Cu composite is 219.7 MPa higher than those of pure copper (220.5 MPa), respectively. This is due to the ability of the graphene to hinder the perpendicular grain growth of the copper. Additionally, the interface between the layered graphene and copper contributes to the annihilation of dislocations, resulting in lower recrystallization kinetics, ultimately retarding grain growth. Furthermore, graphene acts as a barrier to the rearrangement and release of dislocations during the heat treatment process. Gr/Cu composite with good high-temperature stability offers the prospect for high-strength and high-electrical conductivity copper to be employed under high-temperature conditions.