Zum Reibungs- und Verschleißverhalten von Polymerwerkstoffen
The purpose of the study was to find conditions that would aid in the selection of materials for plastic/steel and plastic/plastic slide partners (tribological pairings).
The investigations mainly involved PA, POM and HDPE in their unreinforced state. Their properties differ significantly in terms of surface energy, but not in terms of strength compared to steel.
Altogether, the experiments have shown that friction and wear phenomena can be attributed to adhesion and deformation mechanisms under laboratory slide conditions, as well. Smooth steel surfaces (Rz < 0.3µm) and slight-to-medium surface pressures (p < 1 N/mm2 ) could be found to be prerequisite for adhesive slide. However, mainly deformative mechanisms act on rough surfaces (0.3mµ < Rz < 2.8µm) and/or medium surface pressures p > 1 N/mm2 . Thus it is possible to determine the optimum roughness of a steel surface for non-polar or polar plastics. The effect at the boundary layer can be evaluated via surface energy and its polar and disperse components.
The work of adhesion was determined for a series of plastic/plastic partners using contact angle measurements. Adhesive slide is dominant among these partners, and there is an exponential relationship between the work of adhesion and the adhesively determined coefficient of sliding friction.
The materials parameters which provide a rough correlation with deformatively determined friction and wear behavior are the modulus values and/or energy absorption capability of the plastic. For example, using the energy absorption to yield detected in tensile deformation tests, it is remarkably easy to evaluate deformatively determined sliding wear between plastic/steel partners. This is substantiated by experiments on PA samples in which wetness, relative molecular mass or different degrees of wetting are varied, whereby the energy absorption changes each time.
Between plastic/plastic partners, the material with the higher surface energy clearly exhibits less wear.Lesen Sie die deutsche Zusammenfassung auf Kunststoffe.de
wear particle, adhesive slide, deformative slide, sliding wear, surface tension, surface roughness, polyamide, polybutylene, polyethylene, polyoxymethylene, plastic/plastic partners, plastic/steel partners friction of rest, 2-disk test rig, stick/slip behavior, pin-on-disk test rig, materials transfer
Institute / chair: Fakultät für Maschinenbau der Universität Karlsruhe (TH)
Technical consultant for expert services: Prof. Dr. rer. nat. Eckard Macherauch (Betreuer), Prof. Dr. rer. nat. Otmar Vöhringer, Prof. Dr.-Ing. Gottfried W. Ehrenstein
Publication year: 1980
Provider: Wissenschaftlicher Arbeitskreis Kunststofftechnik (WAK) / Kunststoffe.de
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