(中南大学 粉末冶金国家重点实验室，长沙 410083)
摘 要: 分别采用不同粒度鳞片石墨(鳞片石墨Ⅰ、Ⅱ、Ⅲ)和沥青石墨通过粉末冶金法对铜石墨电刷材料进行制备，采用XRD和SEM对其试验前后的物相和组织形貌进行分析，并运用XPS分析对偶件的表面成分。结果表明：随着石墨粒度的下降，铜石墨电刷材料的烧结密度、硬度和抵抗磨粒磨损的能力均有所下降，抵抗电弧烧蚀的能力则显著提高。沥青粘结剂能够促进铜和石墨的均匀分布，从而改善材料的物理力学性能和摩擦磨损性能。此外，产生于摩擦界面的CuO降低材料的导热导电能力并催化石墨氧化，从而加剧磨损。
关键字: 石墨粒度；沥青粘结剂；摩擦；磨损；氧化
（State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China）
Abstract:Copper-graphite brushes were fabricated through powder metallurgy method by flake graphite with different sizes (graphiteⅠ, Ⅱ, Ⅲ) and pitch binder. The original phase components and structure morphologies were compared with the worn sample by using X-ray diffraction and scanning electron microscopy, respectively. The surface components of counterparts were studied by X-ray photoelectron spectroscopy. The results indicate that physical properties and the ability to resist the abrasive wear will be worse with the graphite granularity decreasing. However, the arc ablation will be enhanced. Uniform distribution of copper and graphite can be achieved by adding pitch binder, which improves the physical and mechanical properties and friction and wear properties. Furthermore, copper oxide generated from friction interface will reduce the thermal and electrical conductivity and catalyze graphite oxidation, which exacerbates the wear performance.
Key words: graphite granularity; pitch binder; friction; wear; oxidation
