Effect of Normal Load on Friction and Wear Properties of Stainless-Steel/Copper-Metal Impregnation Carbon under Electric Current

The current-carrying friction and wear test for stainless steel/metal impregnation carbon was carried out under different normal loads on a self-designed pin-and-disc friction and wear tester.The effect of normal load on its friction and wear properties was analyzed,and the morphology of the worn surface was observed by SEM.The results indicate that the friction coefficient decreased with the increase of normal load,then kept stable until 160 N.When the current was 10 A,wear rate of the pin sample was very low and its increasing trend of change was not obvious.When the current was 30-50 A,the wear rate increased remarkably and then decreased with increasing of normal load,and kept stable at last.Furthermore,the discharge strength decreased with increasing of the normal load.Arc erosion and oxidative wear were dominant wear type with low normal load,abrasive wear and adhesive wear were dominant with high normal load.And both were accompanied with material transfer.