Effect of graphene on microstructure and properties of Gr/CuCr10 composites

Gr/CuCr10 alloys with graphene contents of 0.1 wt.%, 0.3 wt.%, 0.5 wt.%, and 0.7 wt.% were prepared by a hot pressing sintering process. Compared with CuCr10 alloy, the relative density of CuCr10 composite with 0.3 wt.% addition of graphene remained constant, while the electrical conductivity increased from 62.2% (IACS) to 69.5% (IACS). The main reason for the increased electrical conductivity is that the addition of graphene leads to the size reduction of Cr phase and thus reduces the scattering of electrons. In addition, Brinell's hardness of 0.3 wt.% Gr/CuCr10 composite increased from HB 91.8 to HB 99.6 compared with that of CuCr10 alloy. The graphene was mainly distributed at the interface of Cu and Cr. A nano-Cr23C6 phase, which has been observed through HRTEM, is the main reason for the wettability enhancement at the interface of Cu and Cr, thus improving the hardness of the material.