Powder-metallurgical construction of graphene-like nanosheet network reinforced Cu composites towards balanced high-performance

Abstract

The size and grain conformality of the metallurgical precursor powder significantly affect the comprehensive properties of metal matrix composites. To address this challenge, homogeneous hybrids of graphene-like nanosheets coated Cu (GLNs@Cu) particles with controllable sizes are synthesized through an in-situ decomposition of cupric tartrate. Subsequently, graphene-like nanosheet network reinforced Cu (GLNN/Cu) composites are prepared by a powder-metallurgical method from the GLNs@Cu particles based on a thermal-pressing welding mechanism. The 3D-GLNN are uniformly dispersed throughout the Cu matrix, creating an isolation structure over the Cu grains, and acting as a barrier to grain fusion resulting in grain conformality of the composites. Simultaneously, the 3D-GLNN distributes along the Cu grain boundaries establishing inter-connected pathways for the electrons, thereby maintaining high electrical conductivity while refining the grain size of the Cu composites. It is precisely because of this, the GLNN/Cu composites exhibit a tensile strength of ∼500 MPa, approximately 3 times higher than that of the pure Cu. In addition, the interlinked 3D-GLNN provides an electron transport channel for the Cu composite as well as an isolation structure from the corrosive medium, which makes the Cu composite maintain an electrical conductivity even higher than the pure Cu and a corrosion rate of 48.9 % compared with the pure Cu.