石墨粒径大小对铜基石墨复合材料摩擦学性能的影响

Effect of graphite particle size on tribological properties of copper matrix graphite composites

文章采用雾化纯铜粉作为基体,粒径为2、30、60、90μm的片状石墨粉作为固体润滑相,通过粉末冶金法制备了铜基石墨复合材料。研究了石墨粒径大小对材料的力学性能、组织以及摩擦学性能的影响,探讨了石墨粒径大小与摩擦表面石墨覆盖程度的关系。结果表明:随石墨粒径增大,材料的力学性能存在一个最佳值,即当石墨粒径为30μm时,密度达到最大值7.51 g/cm3,硬度为53 HV。摩擦试验结果显示,石墨粒径为30μm时,磨损量最小。通过成分面扫描分析接触面石墨覆盖情况,研究了石墨在摩擦表面的成膜分布情况,结果发现随着石墨粒径的变大,石墨成膜覆盖率变小。

The copper matrix graphite composites were prepared by powder metallurgical method using atomized copper powder as matrix and flake graphite powders(particle sizes of 2,30,60 and 90μm)as solid lubricating phase.The effect of graphite particle size on mechanical properties,microstructure and tribological properties of the material was studied.The relationship between the graphite particle size and the coverage of graphite on the friction surface was also discussed.The results showed that as the graphite particle size became larger,the mechanical properties of the material had an optimal value,when the particle size of graphite was 30μm,the density of the composite reached a maximum value of 7.51 g/cm3 and the maximum hardness was 53 HV.The friction test results showed that when the particle size of the graphite was 30μm,the wear of the composite was the lowest.The graphite coverage on the friction surface was analyzed by selected area composition scanning,the distribution of the formed graphite film on the friction surface was studied,and it was found that as the graphite particle size became larger,the coverage of the formed graphite film became smaller.