Cr3C2 reinforced Cu-graphite composites fabricated by a novel in-situ decomposition using Cu-coated graphite and Cu-coated Cr2AlC

Abstract

Cu-graphite composites are widely used as an important friction material in various fields. However, these composites suffer from weak interfacial bonding and low strength of the Cu matrix. This study focuses on enhancing the properties of these composites by plating Cu on the surfaces of graphite and Cr2AlC, followed by vacuum sintering. The microstructure and interface properties of the composites were investigated using SEM, EDS, and XRD techniques. It was observed that, under the peeling action of molten Cu, Cr2AlC decomposes in situ to synthesize Cr3C2 as reinforcement. Furthermore, a reaction between Cr atoms from Cr2AlC and carbon atoms on the graphite surface forms an interfacial transition layer, significantly improving the interfacial bonding between the Cu matrix and graphite. The resulting composites demonstrate favorable density, hardness, and lubrication properties, with a relative density of 96.2 %, hardness of 86.2 HV, and friction coefficient of approximately 0.15.