石墨粒度对电刷材料用Cu-石墨复合材料组织及性能的影响

Effects of Graphite Granularity on Microstructure and Properties of Cu-Graphite Composites for Brush Materials

通过材料性能测试手段研究石墨粒度对电刷材料用Cu-Sn粉末压坯组织及性能的影响,分析了该材料磨损后的形貌和氧化行为。研究结果表明：对于没有粘结剂的样品,随石墨粒度增大,硬度与烧结密度升高,开孔率下降;有粘结剂的样品烧结密度提高,开孔率下降。较大石墨粒度样品形成了具有集中孔洞的区域。石墨粒度越低磨损现象越显著,其样品摩擦表面形成的犁沟数量也不断减少,铜基体形貌也变得更加光滑。在摩擦过程中,Cu区域被Cu2O区域包围,特别是处于孔洞或者石墨和铜的界面处,材料内部也发生了氧化反应。

The effects of graphite granularity on the microstructure and properties of Cu-Sn powder for brush materials were researched by means of materials properties testing. The morphology and oxidation behavior of the materials after wear were analyzed. The results show that, for the samples without binder, the hardness and sintered density increase and the porosity decreases with the increase of graphite particle size. The sintered density of the sample with binder increase and the porosity decreases. Region with concentrated forms in the by graphite particle size samples void. The smaller the particle size of the graphite is, the more obvious the wear phenomenon is, the number of furrows formed on the friction surface of the sample decreases, and the morphology of copper matrix becomes smoother. In the friction process, the Cu region is surrounded by the Cu2O region, especially at the void or the interface between the graphite and copper, and the oxidation reaction also takes place inside the material.