The effect of solid solutions in the primary structure of composites on the stability of their surface layers during shear in dry sliding contact with high electric current density

Abstract

Dry sliding of powder metal composites of Cu-steel-graphite compositions under high electric current density was carried out. It was shown that the complication of the primary structure by alloying or by addition of solid phases led to a decrease in the electrical conductivity of the contact and wear resistance. Low wear resistance indicated the low stability of the surface layer due to its low ability to relax stresses by means of plastic deformation in the vicinity of contact spots. It was found that during sliding under current, a tribolayer was formed. The thickness of tribolayer composites increased with the complication of the primary structure. This was also due to a decrease in the plasticity of the primary structure having doped components. It was noted that the tribolayer had a composite structure of the composition of FeO-metal. The absence of FeO on the friction surface led to adhesive deterioration of the tribolayer with high wear intensity and low contact conductivity under low current density. Composites with a complex primary structure formed contact with such characteristics. It was concluded that materials with a doped primary structure were incapable of carrying out a dry sliding current collection with a high current density in contact.