Influence of current on wear modes and transition condition of current collecting materials

It is necessary to understand actual phenomena generated at the electric contacts to suggest the design concept for reducing wear of current collectors such as a contact wire and contact strip in an electric railway. However, rotating wear testing method like pin-on-disk which commonly used to evaluate the wear behavior cannot represent the wear modes of the current collector. In this paper newly linear wear testing method is introduced to represent the wear modes and the wear transition conditions between hard-drawn copper contact wire and iron-based sintered alloy contact strip. As the result, we found that the contact temperature which estimated from contact voltage is depend on current and load, and then friction and wear properties at the current collectors under current condition are classified into three types by the maximum contact temperature.