TRIBOLOGICAL CHARACTERISTICS OF THREE-COMPONENT SOLID-LUBRICANT COMPOSITES BASED ON POLYETHERIMIDE UNDER CONDITIONS OF POINT AND LINEAR TRIBOCONTACTS

10.25712/ASTU.1811-1416.2022.03.013

Abstract

The structure, mechanical and tribological characteristics of composites based on polyetherimide (PEI) reinforced with long carbon fibers and simultaneously filled with solid lubricating fillers of various nature (PTFE, graphite) under conditions of point and linear tribological conjugations have been studied. It is shown that an increase in the tribological properties of three-component reinforced, antifriction composites based on PEI under the conditions of point and linear tribocontacts is due to the formation of a transfer film/tribolayer, the patterns of formation of which are determined by the triboactivity of the modifying (solid lubricating) filler and the conditions of triboloading (tribocontact scheme). The determining role of the scheme and conditions of tribological testing (point contact, "ball-on-disk" scheme and linear contact, "block-on-ring" scheme) on the wear resistance of three-component high-strength antifriction composites based on PEI is shown. With point contact and low roughness of the counterbody R_a = 0.02 µm in three-component composites, PTFE is a more effective solid lubricating component. With linear contact and high roughness of the counterbody R_a=0.2 µm, graphite particles are more effective, since they allow the formation of a stable tribolayer on the sliding surface of composites during metal-polymer triboconjugation. The formation patterns of the tribolayer are determined by the triboactivity of the modifying (solid-lubricating) filler and the conditions of triboloading. The operating conditions of the developed high-strength antifriction composites are determined by the difference in the interlayer energies of the solid lubricating (layered) fillers used in the work, their efficiency in the formation of a transfer film/tribolayer of PEI-based composites, and loading conditions.