Study on Friction and Wear Properties of Copper-Impregnated Carbon Slide Plate Under Different Humidity Conditions

AbstractThe pantograph–catenary system is one of the most commonly used power-receiving modes of metro trains. Its friction and wear performances are related to the safety and stability of train operation. In this study, a copper-impregnated carbon slide plate material, widely used in numerous metro lines in China, is considered as the research object. The problem of abnormal wear of slide plates caused by the decrease in relative humidity in the autumn and winter in tunnels is studied. Current-carrying friction and wear tests under humidity conditions of 20%, 30%, and 40% relative humidity (RH) are performed to reveal the mechanism of seasonal abnormal wear of slide plates and provide a reference for the service of pantograph slide plates under low-humidity conditions. The results reveal that relative humidity significantly influences the wear process of slide plates; further, the wear rate decrease with an increase in relative humidity. As observed by laser scanning confocal microscopy, with an increase in the relative humidity, the mechanical wear of the slide surface is weakened, arc erosion is enhanced, and surface roughness is increased. The Raman spectral scan showed that with the increasing humidity, the graphitization of the surface material decreased significantly, and the molecular structure changed greatly. Scanning electron microscopy (SEM) and energy-dispersive spectrometry (EDS) analysis reveal that under high humidity conditions, a relatively complete oxide film forms on the slide plate and plays a role in lubrication and protection.Keywords: Pantograph–catenary systemcopper-impregnated carbon slide platerelative humiditycurrent-carrying friction and wear AcknowledgementsThe authors thank GuangXiong Chen, Songnan Liu, and Hao Hua for assistance with the experiment. In particular, the authors thank Zhangmei Hu and Miaomiao Wang at the Analysis and Testing Center of Southwest Jiaotong University for their assistance with SEM and EDS analysis. The authors also extend their gratitude to Yuwei Zhou for her assistance in editing the article.Disclosure StatementNo potential conflict of interest was reported by the author(s).Authors contributionsAll authors contributed to the study conception and design. MH and BY designed and performed the experiments, conducted the observations and analysed the data. YR and LZ contributed to sample preparation. MH and BY wrote the article in consultation with YR, LZ and SX. All authors provided critical feedback and helped shape the research, analysis, and article.Additional informationFundingThis work was supported by the Sichuan Science and Technology Program (grant no. 2022YFH0075), Independent Research Project of State Key Laboratory of Traction Power (grant no. 2022TPL_T03).