Abstract:Silvercoppergraphitecarbon fiber composite material was prepared by powder metallurgy,and friction and wear test of the composite material and the brass slip ring friction pairs was carried out under the atmospheric condition and electric current from 0 to 30 A on a ringblock friction and wear tester.The influences of current on friction coefficient,contact resistance,electric noise and wear loss were analyzed.The results show that the friction coefficient,contact resistance and wear loss are increased with the increasing of electric current,and the electric noise shows a nonlinear relationship with electric current.The friction mechanism of the pairs of silver matrix composites and brass slip rings is mainly adhesive wear under pure mechanical friction conditions,while the friction mechanism is mainly abrasive wear under currentcarrying conditions,the electrical erosion produced by the arc facilitates the occurrence of abrasive wear.The pairs of silver matrix composites and brass slip rings have high reliability under currentcarrying condition from 0 to 30 A,whose electric noise conforms to the related standards.