Abstract This article presents the results of tests of the BrA5 bronze–45 steel reverse sliding friction pair in dispersion-lubricating media characterized by different degrees of surface activity with respect to bronze. Changes in the microstructural characteristics during metal tribodeformation are analyzed from the standpoint of the Rehbinder effect, which determines the possibility of selective transfer (wear-free mode) in tribological conjunction. It is shown that during friction of bronze in lubricating-dispersion media characterized by relatively low surface activity, the effect of the medium on the surface structure of the tribomaterial is based on the implementation of the surface-hardening effect, the total density of dislocations in the deformed near-surface layer increases. The wear intensity in this case is Ih ≈ 1.5 × 10–7 to 4.0 × 10–8. When bronze is subjected to friction in moderately surface-active media, both surface-plasticizing and surface-hardening effects are realized, with the latter predominating. In this case, the wear intensity decreases slightly, taking values in the range of Ih ≈ 1.2 × 10–7 to 1.5 × 10–8. During tribotesting of bronze in media with increased surface activity, the wear intensity of bronze remains at a fairly low level: Ih ≈ 2.2 × 10–8 to 3.0 × 10–8. However, in this case, two crystallographically isostructural solid solutions are formed in the near-surface layer of the tribomaterial, one of which is enriched with copper. Based on the concepts of physicochemical mechanics of contact interaction, the systemic and structural foundations of the materials science approach are presented, which underlie the analysis of the tribological efficiency of liquids used as dispersion media for plastic lubricants.