Synergistic strengthening effect of in-situ synthesized WC1-x nanoparticles and graphene nanosheets in copper matrix composites

In metal matrix composites, it is commonly a hard task to achieve synergistic strengthening and toughening effects between two-dimensional graphene and zero-dimensional nanoparticles (NPs) reinforcements due to their huge dimensional gap. Herein, we developed an in-situ solid-state reaction method to incorporate graphene nanosheets (GNSs) and WC 1-x NPs into copper matrix. It was proved for the first time by thermodynamics and crystallography calculations that the unusual γ-WC 1-x phase can be generated from the solid reaction and maintain stable at room temperature. Thanks to the unique distribution types of WC 1-x , i.e. intergranular or intragranular distribution while other parts anchored on the surface of the GNSs, Orowan strengthening and load transfer strengthening were simultaneously achieved in the composites. Meanwhile, the thermal conductivity was also measured to be equal to that of pure Cu, exhibiting a promising prospect in applications as advanced multifunctional structural materials.