| As a functional filler-reinforced polymer matrix material,micro-nano particles can significantly reduce friction and wear,and have broad applications in the field of friction.At present,the development of self-healing materials with long life and high reliability has become a research hotspot at world.Attapulgite(ATP)has been widely concerned by tribologist,which has its own unique physical and chemical structure and regard as a potential self-healing material.Previous studies mainly focused on the separation of ATP and the lubrication mechanism of ATP as an oil additive.However,there are few studies on ATP as a polymer filler,and the effect of ATP on the tribological properties of polymer materials has not been systematically studied,especially the tribological mechanism of the friction interface of nanocomposites is not yet clear.This work is mainly based on the research of ATP after fine processing,filled with epoxy resin(EP),polyether ether ketone(PEEK)and polyimide(PI)three polymer matrices,and studied ATP-filled polymer materials.The tribological behavior under dry friction conditions,using advanced characterization and analysis techniques,the influence mechanism of the growth of nanohybrid transfer film at the tribo-pair interface was discussed in depth through the microscopic morphology characterization and friction chemical analysis of the worn surface,revealing ATP enhances the friction mechanism of different polymer matrices.The main conclusions drawn through experimental analysis are:1.Ionic liquid(IL)and silane coupling agent(KH550)was used to functionalize the surface of ATP nanopowders,and then a functionally modified ATP reinforced EP composite material was prepared.Using the TRM-1000 pin-disk friction and wear tester,the tribological properties of different functional modified ATP reinforced EP resin materials and bearing steel as a friction partner under dry friction conditions were systematically studied,combined with the microscopic morphology of the friction surface Characterization and interfacial tribochemical analysis explained its tribological mechanism.Results show that the surface functional modification can significantly inhibit the agglomeration of ATP,improve its dispersion in the resin matrix and its combination with the resin matrix;filling with 3 wt.%ionic liquid functionalized modified ATP,the wear rate of EP resin composites is significantly improved,which is 60%higher than that of pure EP resin.The iron oxide and silicon oxide-based hybrid transfer film formed at the interface avoids the direct contact of the tribo-pair and significantly improves the counterpart bearing capacity,thus improving the lubrication performance of the composite and reducing its wear performance.This research can provide new ideas for expanding the development and application of ATP as a friction functional mineral filler in the development and application of wear-resistant polymer materials.2.The ATP nanofibers were introduced into the PEEK matrix reinforced by chopped carbon fibers(CF)to prepare PEEK composites.The research results show that adding ATP or CF alone can only improve the wear resistance of PEEK,but when the two are added together,the materials tribological performance are greatly increased.It proves that there is a synergistic effect between ATP and CF,which can form a thick and uniform hybrid transfer film on the friction interface.With the increase of the pv value,the dissolution rate of the ATP layer structure is accelerated.The increase in the number of nanoparticles released into the counterpart accelerates the formation of the tribo-film.Greatly improve the tribological properties of PEEK materials.The research is for the development of new high-performance polymer self-lubricating materials,which is of great significance to improve the service life and reliability of the motion mechanism.3.The nanoparticles(silicate ATP and Si O2)not only can inhibit the oxidation of the counterpart,but also effectively protect the surface of the tirbo-pair.In addition,compared with Si O2,ATP has better wear resistance and lubricity than Si O2 no matter under low speed and high load,or under high speed and high load,and its stability is better.The main reason is that a layer of iron-containing oxides and ATP oxides(Si O2?Al2O3?Mg O),which effectively inhibits the occurrence of friction oxidation and protects the friction pair surface.Besides,the friction chemical reaction of iron occurs during the friction process,and the formation of Fe OOH enhances the robustness and robustness of the hybrid transfer membrane.In this paper,by studying the dry tribological mechanism of ATP-reinforced polymer composites,to a certain extent,it provides some ideas for the development and application of ATP in the field of polymer self-lubricating materials and wear-resistant polymer materials. |
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