Abstract:
The copper powder and graphite powder were mixed by ultrasonic dispersion, combined with mechanical ball milling wet grinding method. The graphite/copper composite was prepared by spark plasma sintering (SPS) technique. The effect of sintering temperature on the microstructure and properties of graphite/copper composite was investigated by using scanning electron microscopy(SEM), X-ray diffraction(XRD) and conductivity meter. The results showed that the graphite was dispersed uniformly on the copper matrix and formed a good interface by using the ultrasonic dispersion and mechanical ball milling wet grinding method. When the sintering temperature was raised from 700 ℃ to 750 ℃, the relative density, Vickers hardness, compressive strength and electrical conductivity of the graphite/copper composite increased by 1.6%, 6.7%, 11.3% and 5.3%, respectively. However, the properties of graphite/copper composite showed a downward trend with the temperature increasing from 750℃ to 900℃. When the sintering temperature was 750℃, the graphite/copper composite had a dense structure and uniform grain size distribution: the average grain size was about 6.4 μm, the relative density was 96.3%, the Vickers hardness(
HV0.5) was 60.7, the compressive strength was 422 MPa and the conductivity was 86.7% IACS. Its overall performance was at its best.