Ag-MoS2复合材料电磨损表面膜结构和形成机理研究

Structure and Formation Mechanism of Surface Film of Ag-MoS2 Composite during Electrical Sliding Wear

摘要:

采用粉末冶金方法制备了Ag-MoS2复合材料。初压压力300 MPa，在H2保护气氛下烧结并保温1 h，经500 MPa压力的复压过程制得复合材料，用XRD对烧结后的材料进行了物相分析。对材料进行电磨损实验，并对磨损后的材料表面进行XPS分析。结果表明，复合材料在烧结过程中Ag基体和MoS2并未发生化学反应，而在磨损过程中，由于电流和化学作用，材料表面产生了MoO3，MoO2，同时由粘着作用从对磨环转移到电刷表面的铜与大气分子发生化学反应产生了Cu2O, CuO and Cu2S。表面膜的存在降低了材料的摩擦系数，影响着材料的电磨损性能。

Abstract:

Ag-MoS2 composite brushes were fabricated by means of powder metallurgy process. The composite was detected by the method of XRD after sintering, and the worn surface of the brush was analyzed by XPS after the wearing experiments with current. Results showed that the components of the composite didn’t change during sintering, but the surface components of it changed upon wearing and some matters such as MoO3 and MoO2 were produced. At the same time, Cu2O, CuO and Cu2S were detected due to the adhesion transfer of elemental Cu from the slipping ring to the brush surface and the reaction between the elemental Cu and the ambient air molecules. During electrical sliding wearing, the surface film can reduce the friction coefficient and be beneficial to the frictional performance of the material