Investigation on the Novel High-performance Copper/Graphene Composite Conductor for High Power Density Motor

High-performance Cu/Graphene composite wire synergistically strengthened by nano Cr 3 C 2 phase was directly synthesized via hot press sintering followed by severe cold plastic deformation, using liquid paraffin and CuCr alloy powder as the raw materials. Since graphene is in situ formed under the catalysis of copper powder during the sintering process, the problem that graphene is easy to agglomerate and difficult to disperse uniformly in the copper matrix has been solved. The nano Cr 3 C 2 -particles nailed at the interface favor to improve the interface bonding. The Cu/Graphene composite possesses high electrical conductivity, hardness, and plasticity. The composite wire exhibits high electrical conductivity of 96.93% IACS, great tensile strength of 488 MPa, and excellent resistance to softening. Even after annealing at 400°C for 1 h, the tensile strength can still reach 268 MPa with a conductivity of about 99.14% IACS. The wire's temperature coefficient of resistance (TCR) is largely reduced to 0.0035/°C due to the complex structure, which leads the wire to present low resistivity at higher temperatures. Such Cu/Graphene composite wire with excellent comprehensive performance has a good application prospect in high-power density motors.