Sliding contact characteristics between self-lubricating composite materials and copper

Simultaneous measurements of contact electric resistance and coefficients of friction on three types of composite materials containing laminar solid lubricants were conducted. Contact resistances of new composite materials (CM-4, CM-5) were as low as 1/10, compared to those of a previously prepared composite material (CM-1) in the range of the measurement conditions (50-1000 gf, 0.1-10 A). Coefficients of friction for the new materials were slightly higher because of the reduction of the contents of solid lubricants by the additions of Cu, Sn, and Ag for lowering the resistivities. It was concluded that these new composite materials were sufficiently beneficial for use in sliding electric contacts. The current-voltage characteristics indicated that the occurrence of fritting phenomena observed on the composite material CM-1 was not observed on CM-4 and CM-5, because the generation of Joule´s heat was suppressed by the effective functioning of solid lubricants with the resistance of CM-4 and CM-5 lower than that of CM-1.<>