Cu/Ag/石墨复合涂层电滑动摩擦磨损行为研究

运用等离子喷涂技术在C45E4基材上制备了Cu/Ag/石墨复合材料涂层。利用HST-100销-盘式摩擦磨损试验机，研究了不同电流强度对Cu/Ag/石墨复合材料涂层摩擦磨损行为的影响。利用场发射扫描电镜、能谱仪和X射线衍射技术对涂层结构、相组成、磨损形貌和磨屑进行了表征。涂层结构分析表明：Cu/Ag 合金形成了连续的导电通道而沉积的石墨颗粒具有明显的平行于基材的取向。随着电流从0增加到50A，复合材料涂层的磨损率随之增大，而且磨损率与施加的接触压力和滑动速度有紧密的联系。在本实验中，观察到在相同接触压力和滑动速度条件下，摩擦系数与电流强度几乎无关的现象。石墨转移膜和氧化物层是形成稳定滑动的主要因素。没有电流时，磨损机理主要是磨粒磨损，但随着电流的增强，电磨损变为滑动过程中复合材料的主要磨损机理。

The Study on Electrical SlidingTriblogical Behavior of Cu/Ag/Graphite Composite Coating

In this work, Cu/Ag/Graphite coating was deposited on steel substrates by plasma spraying process. The tribological behavior of Cu/Ag/Graphite coating under different currents has been tested using a HST-100 pin-on-disc friction and wear tester in an air atmosphere with humidity of about 50%. The coating microstructure, phase composition,worn surface and debris were characterized by field emission scanning electron microscope (FESEM), energy dispersive X-ray spectrum (EDS) and X-ray diffraction (XRD). The results show that Cu/Ag alloy forms a continuous metal network in as-received coating and the deposited graphite particle demonstrates an obvious orientation direction parallel to the substrate. With the increasing current from 0A to 50A, it was found that the wear rate of Cu/Ag/Graphite coating is increased and related closely with the pin contact pressure and sliding velocity. It is of interesting to note that the friction coefficient of Cu/Ag/Graphite coating was not affected by the increasing currents under the same contact pressure and velocity in this work. Graphite transfer film and oxidization layer were the main reasons for stable electrical sliding process. Under no current applied, the wear mechanism was abrasive wear; however, the electrical wear would become the main wear mechanism with the increase of current intensity during electrical sliding process.