Title: Investigation of tribological properties of sheet metalfluoroplastic materials
Abstract: The paper presents the results of tribotechnical tests, TG-, IR- and XRD analysis of wear products of sheet metalfluoroplastic material with lead (SMFM-Pb) in friction with hardened steel with high slip velocities. Tribotechnical tests shows that wear reduction during operation without lubrication in such regime is ensured by the presence in the working layer of a large volume of the PTFE-composition. Moreover, the Charpy rule for friction of SMFM-Pb with minimum wear rate is fully observed when the component of solid inclusions on the friction surface, in this case of the bronze frame, is one order of magnitude less softer and more shear-tolerant then the PTFE composition surrounding it, which is main donor during formation of the intermediate antifriction layer. Based on the IR, XRD analysis of wear products of SMFM-Pb, it can be said that the intermediate layer and the layers on the friction surfaces sheet metalfluoroplastic material with lead and counterbody have an inhomogeneous composition and consist of organofluorine compounds serving as a lubricant, including a mixture of lead oxyfluorides, fluorides and oxides. Pure PTFE is predominantly transferred to the counterbody, which is confirmed by the halo and reflex, characteristic of the amorphous and crystalline phases of polymer. In combination with a layer of PTFE transferred to the surface counterbody as highly oriented lamellas having a bearing high capacity and high surface hardness of the counterbody, the resulting third body provides increase of pV-factor a new SMFM-Pb at the maximum allowable temperature of 500-520 K to 5 MPa×m/c.