Deformation behavior and microstructure evolution of graphene/copper laminated composites

Abstract

The strength and electrical conductivity of copper-based conductors are always contradictory, while graphene/copper (Gr-Cu) composites are expected to meet the strict requirements of high strength, high conductivity, and even high thermal stability conductors’ materials. In this work, hot compression and cold rolling behaviors of Gr-Cu composites were investigated. The results indicate that graphene at the Gr-Cu interface in the composites can inhibit dislocations movement and grain boundary migration thus affecting dynamic recovery and recrystallization during hot compression. The pinning effects of dispersed graphene on grain boundaries were gradually weakened, leading to the coarsening of grains at 850 °C. Moreover, the thermal processing maps were plotted and the optional thermal processing parameters of 650-850 °C and 0.03-0.35 s-1 were determined. In addition, laminated Cu grains were refined to nanoscale after 98% rolling reduction owing to inhibiting restoration by the dispersed graphene. The Gr-Cu interface in the composites assisted deformation and induced nanotwins resulting in pronounced Brass type texture after 50% rolling reduction. Furthermore, the dispersed graphene enhanced the thermal stability and nanotwins were remained stable at 1073 K for 1h.