<p>The processes occurring on the friction surface of polymer composite materials (PCMs) based on polytetrafluoroethylene (PTFE) and layered (LS) silicates such as serpentine and phlogopite are described in the article. The studies were carried out with a scanning electron microscope and X-ray photoelectron microscopy and indicated the occurrence of tribo-oxidative processes in the polymer/metal contact zone. The investigation of the elemental composition of the friction surface by energy dispersive analysis revealed the appearance of new peaks corresponding to Fe and Cr. This fact indicates the interaction of the counterbody metal with the polymer during friction. The occurrence of defluorination and hydroxylation reactions of PTFE macromolecules on the friction surface of PCM was recorded based on the results of X-ray photoelectron spectroscopy. A possible mechanism is proposed for the tribochemical processes that occur on the friction surface of composites, regardless of the composition of the fillers. It has been established that a protective layer is formed consisting of filler particles and tribodestruction products due to tribochemical reactions on the friction surface. The formation of a secondary layer is not observed in the case of a composite with phlogopite. Thus, the main factor in increasing the wear resistance of PTFE-based PCM is the formation of new secondary structures on the friction surface in the friction zone due to the occurrence of tribo-oxidative processes. The generated secondary structures provide a protective surface that contributes to the shear friction stress.</p>