Synchronously improved mechanical strength and electrical conductivity of Carbon/Copper composites by forming Fe3C interlayer at C/Cu interface

Carbon/Copper (C/Cu) composites have been widely used in aerospace, transportation and military products because of their excellent properties of mechanical strength, self-lubrication and electrical conductivities. One of the challenges in preparing C/Cu composites materials is how to overcome the poor wettability between Cu and carbon. In this study, ultrafine iron oxide (Fe2O3), as a precursor, was introduced into the carbon matrix to improve the C/Cu interfacial bonding of C/Cu composites prepared by pressure infiltration. The effect of Fe on the phase composition, microstructure and properties of C/Cu composites were systematically evaluated. The results revealed that the interfacial bonding between Cu and carbon was enhanced by the “bridge architecture” of iron carbide (Fe3C). The wettability between Cu and carbon improved for the contact angle decreased from 124° to 38°. Compared with the unmodified composites, the composites doping 5 wt% Fe2O3 exhibited best performance. The compression and flexural strength increased by 37.4% and 120.4% respectively. Meanwhile, the electrical conductivity improved by 283.7%. It was concluded that the Fe3C layer had an important effect on the electron transport and crack propagation of the C/Cu composites.