Polymere mikro- und nanoskalige Compounds mit verbesserten tribologischen Eigenschaften

Translated title of the contribution: Polymeric micro- and nano compounds with improved tribological properties

Matthias Walluch

Research output: ThesisMaster's Thesis

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Abstract

Nowadays, ecological awareness has become widespread and is still increasing. Likewise, engine and gear developers are looking for new ways to reduce CO2 emissions from vehicles. In relation to gears this can be achieved by a reduction of friction losses which occur between the chain and the polymer chain guiding that is responsible for the steady running of the chain. There are several ways to improve the sliding properties, for example changing the layout of the chain drive systems, the geometry of the sprockets or the chain type. What is more, a modification of the polymer can reduce the friction that occurs between the chain and the chain guiding; consequently, the losses can be kept to a minimum. The aim of this thesis is to examine how friction losses between steel and the polymer can be reduced through a modification of the polymer with different micro- and nanoparticles. In order to achieve the necessary modification it is essential to find polymers that are suitable for building chain guides and that may be used as possible alternatives to the currently used material. The three chosen polymers include two types of polyamide 66, one of which is the currently used material, as well as a type of polyamide 46. The three polymers were used as the matrix material for compounds with 5 % by weight of different nanoparticles. The used additives encompass different layered silicates, quartz sands with spherical particles and polytetrafluoroethylene (PTFE). The 51 samples (48 compounds and three unmodified polymers) were pressed to sheets which were subsequently tested for their tribological properties by employing the pin-on-disc microtribometer. In addition, experimental investigations were performed to determine the influence of different additives on the friction coefficient of the different compounds under different contact pressures and at different relative speeds in a lubricated friction system. Then the wear of each sample was analysed without oil lubrication. The first results show that some of the friction and wear values of the unfilled polyamide 66 types were sufficiently lower than those of the polyamide 46. Furthermore, the results show that it is possible to improve the values of the friction and wear coefficients of the PA 66 types by adding layered silicates. The effect of layered silicates on PA 46, however, was only marginal. Generally, the most positive influence on wear and friction behaviour of the polymers was achieved by adding a layered silicate. All tests on this compounds show an improvement of the tribological properties compared to the unfilled polymer. The use of PTFE or spherical fillers in contrast does not lead to far better results compared to the matrixmaterials. The results of this thesis shall serve as a basis for further testing and optimization of the tribological properties of these compounds. What is more, it is planned to conduct tests regarding the influence of temperature on the friction behavior of some of the compounds and to vary the degree of filling of the polymers in order to determine an ideal filler content. Also, filled polymer blends may be produced as a next step.
Translated title of the contributionPolymeric micro- and nano compounds with improved tribological properties
Original languageGerman
QualificationDipl.-Ing.
Supervisors/Advisors
  • Witschnigg, Andreas, Co-Supervisor (internal)
  • Holzer, Clemens, Supervisor (internal)
Award date13 Dec 2013
Publication statusPublished - 2013

Bibliographical note

embargoed until 09-12-2018

Keywords

  • pin-on-disc
  • pin on disc
  • tribology
  • wear
  • friction
  • PA 66
  • PA 46
  • layerd silica
  • COF

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