石墨取向化铜基摩擦材料的性能研究

Study on properties of graphite oriented copper-based friction materials

以Al2O3弥散强化铜粉为基体,镀铜鳞片石墨为润滑相,通过冷压薄坯层叠热压烧结工艺制备了鳞片石墨取向化分布的铜基摩擦材料,采用扫描电子显微镜观察了鳞片石墨在铜基体中的分布情况,并对铜基摩擦材料的密度、硬度、抗压强度、热导率及摩擦性能进行了测试与分析。结果表明:制备的铜基摩擦材料组织中鳞片石墨分布均匀,与铜基体结合良好,石墨片与压制方向趋向于垂直,鳞片石墨之间平行分布;垂直压制方向比压制方向具有更高的硬度和抗压强度,垂直压制方向的热导率是压制方向的3倍,且在高鳞片石墨体积分数下垂直压制方向具有比压制方向更低的摩擦因数、磨损量和摩擦表面温度。

Copper-based friction materials with oriented distribution of flake graphite were prepared by cold-pressing and hot-pressing sintering process with Al2 O3 dispersion-strengthened copper powder as matrix and copper-plated flake graphite as lubricating phase. The distribution of flake graphite in copper matrix was observed by scanning electron microscopy,and the density,hardness,compressive strength,thermal conductivity and friction properties were tested and analyzed. The results show that the flake graphites are distributed uniformly in the copperbased friction material,and have good bonding between copper matrix. The graphite sheet tends to be perpendicular to pressing direction. The vertical compaction direction have higher hardness and compressive strength than the compaction direction. The thermal conductivity of the vertical compaction direction is three times higher than that of the compaction direction,and the friction coefficient,wear rate and friction surface temperature of the vertical compaction direction are lower than that of the compaction direction at high flake graphite volume fraction.