Interface and mechanical/thermal properties of graphene/copper composite with Mo2C nanoparticles grown on graphene

Mo2C nanoparticles grown on reduced graphene oxide (Mo2C@RGO) were used to prepare the Mo2C@RGO/Cu composite. The Mo2C nanoparticles played a bridging role in not only being firmly attached on RGO but also forming a semi-coherent interface with the Cu matrix, leading to strong interfacial bonding of the composites. The 1 vol% Mo2C@RGO/Cu composite exhibited a yield strength of 238 MPa, 58% and 127% higher than that of 1 vol% RGO/Cu composite and pure Cu, respectively. The strengthening mechanism of Mo2C@RGO/Cu composite relied on the dual role of Mo2C nanoparticles that not only enhanced the load transfer strengthening of RGO but also provided the possible Orowan strengthening themselves. Nevertheless, the Mo2C@RGO/Cu composite showed a drop in coefficient of thermal expansion but a reduced thermal conductivity compared to pure Cu and the RGO/Cu composite. This study provides new insights into the interface structure, strengthening mechanism and thermal behavior of carbide-modified graphene/metal composites.