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Projekt Druckansicht

Einfluss von Transferfilm-Bildungsmechanismen auf Reibung und Verschleiß von Polymermatrix-Verbundwerkstoffen

Antragsteller Dr.-Ing. Bernd Wetzel
Fachliche Zuordnung Polymere und biogene Werkstoffe und darauf basierende Verbundwerkstoffe
Förderung Förderung von 2018 bis 2020
Projektkennung Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 389811744
 
Erstellungsjahr 2021

Zusammenfassung der Projektergebnisse

The main objective of this project was to improve the understanding of transfer films and the correlation between transfer film formation, transfer film thickness and the tribological performance of the respective material combination. In order to achieve that, the novel method of transfer film lumimance analysis (TLA) was used and optimized and applied to a range of carefully designed and manufactured materials. Our main findings were that there is a significant in-situ correlation between the coefficient of friction and the change of relative luminance, i.e. transfer film formation. While some fillers, like graphite, silica or PTFE form stable transfer films in PPS and EP, other fillers, especially carbon fibers, are disruptive to the transfer film formation process. We were able to demonstrate that combining carbon fibers with other fillers reduced the fibers’ disruptive action to varying degrees, with silica working best. On the other hand, we found no significant impact of silica size (50 nm, 250 nm, 600 nm) or shape on friction, wear or transfer film formation. As we investigated a total of three different representative matrix materials (EP, PA6, PPS), we were furthermore able to demonstrate that fillers do not necessarily exhibit similar behavior in terms of transfer film formation and stability in those matrices, as can be seen from the perfectly stable transfer film formed by carbon fiber filled PA6, in contrast to the high instabilities that carbon fibers cause in PPS and EP. Therefore, transfer film formation and stability seem to dependent significantly on the respective matrix material. In addition to the insights that we have gained from applying TLA to a wide range of materials, we also made great progress in terms of experimental techniques: TLA was developed from a basic concept into a fully working method and we demonstrated how chemical dissolution of transfer films can eliminate the potentially misleading assumption of an unmodified baseline in profilometric film height measurement. The TLA method has been patented. Parallel to our experimental studies, modelling approaches were conducted by our Russian partner at Tomsk. The results were in good match to our test results and are already published.

Projektbezogene Publikationen (Auswahl)

 
 

Zusatzinformationen

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