Current-carrying tribological properties of an elastic roll ring under different currents

A novel rotating conductive joint that comprises an inner raceway, outer raceway, and a roll ring is proposed in this study. The tribological and conductive properties of the rolling rings were studied under current conditions of 0–20 A. The current density of the rolling contact reached 419 A/mm2 when transmitted at 20 A. However, a high current could result in a high-friction coefficient and severe wear. The results of optical microscopy and electron back-scattered diffraction showed that the grain boundary was partially annihilated, and the stress decreased in the wear area under 10 and 20 A. On the wear surface, the current-carrying friction caused the hardening, and the electroplasticity caused softening. The surface hardness of the wear area was the result of competition between hardening and softening, which reached its highest value at 5 A.