Triboparameters of new antifrictional materials under dry friction vacuum conditions for space application

Two self-lubricating copper based composite materials, alloyed with P and Sn or Ni, and containing Pb globular formations, were studied. The obtained experimental values about the friction coefficient of both materials were small (0.12-0.22) under dry friction vacuum conditions at load from 2 to 20 N and velocity 0.2 and 1 m/s. The measured values for wear intensity were also small (6/spl times/10/sup -6/-5/spl times/10/sup -5/ mm/sup 3//N m). The obtained good frictional properties of these composite materials under vacuum conditions were the result of the friction surface enrichment with the metallic Pb that was acting as a solid lubricant. The experience shows that these materials have a high loading level and are adaptable to the friction regime. They are suitable for prolonged exploitation under dry friction vacuum conditions, also in space environment.