一种新的自润滑铜-石墨-NbSe_2复合材料的合成及摩擦性能研究

Tribological Property Improvement of Copper-Graphite Composites by Adding NbSe_2

研究了NbSe2的添加对铜-石墨固体自润滑材料的影响,采用粉末冶金法将制备的不同质量百分比含量的纤维状或片层状的纳米NbSe2材料与铜粉、石墨粉混合均匀,冷压制成小圆盘。采用光学显微镜,SEM(JSM-7001F扫描电子显微镜)等手段表征表面形貌。并在超低温摩擦磨损机和UMT-2摩擦试验仪上测试其摩擦性能。实验结果表明,两种NbSe2的加入使铜-石墨复合材料电阻率降低了近一半;常温常压下,添加了纤维状的NbSe2较片层状具有更好的摩擦学性能,在高载荷下甚至优于铜-石墨复合材料,在真空状态下,无论添加纤维状的还是片层状的NbSe2,复合材料的摩擦系数都远低于铜-石墨复合材料(M为0.257),并且两者在NbSe2添加质量百分比含量6%时达到最低,即铜-石墨-6%纤维状NbSe2为0.189,铜-石墨-6%片层状NbSe2为0.205。

Here,we addressed the impact of the NbSe2 addition on the improvement of tribological properties of the copper graphite composite discs,fabricated by powder metallurgy.The microstructures of the NbSe2 powder and the NbSe2 added composite materials were characterized with scanning electron microscopy and optical microscope.The influence of sample preparation conditions,including the geometry and content of the NbSe2 grains,on its properties was evaluated.The results show that the addition and content of NbSe2 grains,either in the shape of whisks or laminas,significantly improves its properties.For instance,addition of NbSe2 reduces the resistivity by nearly 50%,and when it comes to maximum friction coefficient reduction in air,the whisk-shaped NbSe2 outperforms the lamina shaped NbSe2 grains.The optimized addition content of NbSe2 were estimated to be 6%（wt）.