Achieving high strength and ductility in copper matrix composites with graphene network

Although graphene/copper (Gr/Cu) composites synthesized by most of current methods can be strengthened, they usually suffer from a considerable ductility loss. To tackle this issue, graphene network (GN) is constructed in the Cu matrix based on a powder-metallurgy strategy. The graphene network/Cu (GN/Cu) composites exhibit an excellent combination of high strength and good ductility with small graphene content. The tensile yield strength and ultimate strength of the 1.0 vol% GN/Cu composites are 128.6 MPa and 288.6 MPa, which are respectively 81.6% and 36.8% higher than those of pure Cu, while still maintaining a high ductility value of 35.8%. This work highlights the important role of GN in strengthening and toughening GN/Cu composites. The efficient grain refinement strengthening, dislocation strengthening and load transfer strengthening are achieved through the construction of GN in GN/Cu composites. In addition, effective crack bridging and deflection are provided by the GN, resulting in the toughening of GN/Cu composites.