Experimental Instruments and Methods

Change in the electrical resistance of the metallic composite material-steel contact under friction and electric current

V. V. Fadin, M. I. Aleutdinova

Institute of Strength Physics and Materials Science, Siberian Branch of the Russian Academy of Sciences, Tomsk

Abstract: The I–V characteristics of the sliding contact of metallic composites of grade 45 steel without a lubricant are presented. Steel-based composites are shown to increase the actual electric-contact area due to the appearance of electric discharges, which provide the main passage of an electric current with a density up to 300 A/cm$^2$. Copper-based composites cannot initiate electric-discharge conduction because of the fracture of the contact zone material at a current density higher than 50 A/cm$^2$. The electrical resistivity of the contact layer of metallic composites is calculated. It is found that, during friction with a high current density, the electrical resistivity of the contact layer approaches the electrical resistivity of graphite. It is experimentally shown that the actual electric-contact area can be increased by the introduction of a Pb–Sn melt into the friction zone and reaching a current density higher than 300 A/cm$^2$ in the contact.

Received: 11.03.2010

 English version: Technical Physics, 2010, 55:12, 1802–1807

Bibliographic databases:

•