银-二硫化钼复合材料滑动电磨损机理的研究

Study on mechanics of electrical sliding wear of Ag-MoS_2 composite

采用粉末冶金方法制备银-二硫化钼复合材料,研究了材料在滑动电磨损状态下的摩擦系数、磨损量和接触电压降变化情况,探讨了电磨损发生过程的机理。研究表明:与纯机械磨损相比,电磨损过程中材料的摩擦系数差别不大;在电磨损过程中发生阳极侵蚀现象,材料从阳极向阴极发生转移,正刷的磨损量大于负刷,纯机械磨损量在二者之间;磨损过程中由于正刷侧的二硫化钼膜厚度大于负刷,以及正刷微观导电点的数量少于负刷,使得正刷的接触电压降高于负刷。

Ag-MoS2 composite brushes were fabricated by means of powder metallurgy method. The friction coefficient, wear volume loss and contact voltage drop were studied. The mechanics of the electrical sliding wear was discussed. The results show that there is no difference between the friction coefficient with and without current. The positive pole corrosion happens and the material transfer from the positive pole to the negative pole, thus the wear volume loss of the positive brush is more than that of the negative brush and the wear volume loss of the brush without current is between them. The contact voltage drop of positive brush is higher than that of the negative brush because the film of MoS2 is thicker and the electric conduction pots are more in the surface of the positive brush.