WEAR AND FRICTION BEHAVIOUR OF A LUBRICATED THERMOSET-PAIRING ON A BALL-ON-THREE-PLATES-TEST

摘要

In recent years plastics have become an increasingly important part in the development of new products. Thermosets, especially, have experienced a renaissance ensured by their high mechanical and thermal stability as well as good chemical resistance to many media [1,2]. These properties are enhanced by a high percentage of glass or carbon fibers in the resin [3]. Plastics are used intribological systems for a long time and thermosets a re interesting for tribological systems, due to there properties [4]. Polymers, in pa rticularthermoplastics, a re often applied as bearing bushes for journal bearings, where they a re usually paired with a counterbody made of steel. An example of such an application is a diesel high-pressure pump, where the bearing bushes are often made out of a thermoplastic [5]. For systems which are not exposed to such high loads like in a high-pressure pump, e.g. 2000 bar, pure plastic-pairings can be considered. For automotive applications this option offers a further weight reduction and thus a lower emission of environmentally harmful substances. One possible usage ofsuch a pureplastic-plasticpairing is the pump of sective catalytic reduction (SCR) systems which are used to reduce the nitrogen oxide emissions of diesel engines. In those systems the chemical resistance of the used materials against the reducing medium [6], an aqueous urea solution, is very important and can be provided by filled thermosets based on a phenolic Novolak resin [7]. The followinginvestigations examine whether pure thermoset-painngs can be used for such a tribological system and how these react to different boundary conditions.