Methodenfindung zur Beschreibung der Vorgänge im Kontaktbereich bei Composite-Werkstoffen unter tribologischer Beanspruchung

Research output: ThesisDiploma Thesis

Abstract

Composite materials are inhomogeneous materials that consist of two or more phases which are chemically and physically distinguishable. Through a systematic combination of phases with different properties, it is possible to create composite materials that combine the desired properties of the single phases or even improve them. These materials play an important role in tribological applications as well, for instance, in bearing or seal technology. In praxis, the development and characterization of these materials are mostly done by tribometric tests. In this study, auxiliary techniques for the tribological characterization of particle reinforced composites have been developed. After a theoretical introduction to the tribological function of composite materials, the development of different three-dimensional finite elements method models in ABAQUS is described. The tribological loading capacity of a PTFE/bronze-composite was simulated in a unit cell model. Parameter studies, for elastoplastic material behaviour, were performed with different loads (2.5 N/mm, 5 N/mm, 7.5 N/mm, 10 N/mm), particle percentages (8 %, 12 %, 25 %), temperatures (-15°C, 23°C, 100°C) and matrix-particle-bondings (form locking plus friction, fix bound). Two additional models include the viscoelastic creep behaviour of PTFE in the simulation. A fourth model simulates the fusion of soft phases in a metallic bearing material. The practical part of this work deals with the development of a methodology for in-situ-investigation of the frictional area during sliding. For this purpose a tribometer with pin-on-plate-configuration was engineered and constructed. Here the frictional area could be observed under a light microscope during sliding of the sample against a glass plate. To benchmark the developed methodology, various tests were performed with PTFE/bronze-compound- and organic/inorganic filled TPU-samples. In addition to plain glass plates, roughened glass plates were used for investigating abrasive wear processes. The real contact area and the percentage of exposed particles at the surface have been measured with the phase analysis tool of the image processing software Olympus Analysis.

Details

Translated title of the contributionDesign of a methodology for the tribological characterisation of composite materials
Original languageGerman
QualificationDipl.-Ing.
Supervisors/Advisors
Award date26 Mar 2010
Publication statusPublished - 2010