Effect of Graphene Content on Microstructure and Properties of Gr/Cu Composites

Graphene(Gr) reinforced copper matrix composites(Gr/Cu) were prepared by powder metallurgy process, and the effects of graphene content on microstructure and properties of the composites were investigated. The microstructure, density, hardness and electrical conductivity of the composites were analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), density measurement, hardness tester and conductivity meter. The microstructure results show that with the increase of graphene content, the number of pores in the composites increased continuously, and the interface of the composites was well bonded. It was observed that there was no cracking and obvious interfacial reaction. However there were a lot of dislocations and twins in the matrix Cu, which might be the main reason for the decrease of the conductivity of the composites. The results of the composites’ properties revealed that with the increase of graphene content, the density and electrical conductivity of the composites decreased, the hardness increased first and then decreased. When the mass fraction of graphene was 0.5%, the maximum HBW was 175, and when the mass fraction of graphene was 3%, the density and conductivity of the composites decreased by 12% and 45% respectively, compared with pure copper.