烧结温度对石墨/铜复合材料微观组织与性能的影响

通过超声波分散结合机械球磨湿磨法对铜粉和石墨粉进行混料，利用放电等离子烧结（SPS）技术制备石墨/铜复合材料。运用扫描电镜（SEM）、X射线衍射仪（XRD）和电导仪等表征手段，研究了烧结温度对石墨/铜复合材料的微观组织与性能的影响。结果表明:超声波分散和机械球磨湿磨法可使石墨均匀分散于铜基体，并与铜基体形成良好的界面结合。当烧结温度从700 ℃升高到750 ℃，石墨/铜复合材料的相对密度、维氏硬度、抗压强度和电导率分别提高了1.6%，6.7%，11.3%和5.3%；当烧结温度从750 ℃升高至900 ℃时，其相对密度、维氏硬度、抗压强度和电导率均呈现下降趋势。当烧结温度为750 ℃时，石墨/铜复合材料组织均匀致密，平均晶粒尺寸约为6.4 μm，相对密度为96.3%，维氏硬度（HV_0.5）为60.7，抗压强度为422 MPa、电导率为86.7%IACS，综合性能较优。 

Effect of sintering temperature on the microstructure and properties of graphite/copper matrix composite

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(HV_0.5) was 60.7, the compressive strength was 422 MPa and the conductivity was 86.7% IACS. Its overall performance was at its best.