Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : December 01, 2021 - December 03, 2021
It has been said that lubricative carbon films are formed on the surface of a contact wire when using carbon based pantograph contact strips. However, there are no reports on the observation of such films, and the details of the carbon film have not been clarified yet. In this study, the author investigated the surface of the worn contact wire actually used on a commercial line where the metalized carbon contact strip is applied. From the results of the Raman spectroscopic analysis, it was found that both R value, the D band /G band ratio, and the width of the G band of the carbon film decreased compared to those of the original carbon substrate of the contact strip. It means that the carbon film on the contact wire is not only a transfer film from the contact strip but also a product of graphitization process on a sliding surface. The author also conducted wear experiments using the metalized carbon contact strip sliding against a copper ring under electric current condition. It was found that such graphitization of the carbon was proceeded by only arc discharge not by Joule heat of frictional heat during sliding.
