Project Details
Projekt
Mechanisms of graphite lubrication in rolling contacts
Applicants
Professor Dr.-Ing. Albert Albers; Professor Dr. Martin Dienwiebel; Professor Dr. Michael Moseler
Subject Area
Engineering Design, Machine Elements, Product Development
Term
since 2018
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 407639446
In machine elements such as gears or rolling bearings, greases and oils are mainly used as lubricants. However, simple oil-based lubricants in particular decompose at around 100°C and can lead to wear and failure of the systems. Additives can counteract decomposition, but have other limitations, such as reduced environmental compatibility. In addition, the group of solid lubricants (e.g. graphite, MoS2 or PTFE) represents an alternative, whereby graphite is probably one of the oldest, but still very frequently used solid lubricants in technology.The central objective of the research project is to design a practical concept for the lifetime lubrication of highly loaded rolling contacts with graphite. For this purpose, the build-up process of the transfer layer is investigated by means of micro-tribometry and atomistic simulation. Influencing variables that determine the lubricant film structure and its adhesion to the metal surface are analyzed. At the micro level, the provision mechanisms of graphite in contact are being investigated using the axial ball bearing as an example. Among other things, the surface roughness has shown a strong influence on the transfer layer formation in the first funding period and will be investigated in depth in the second funding phase. The conceptual design of a graphite-lubricated thrust ball bearing is being carried out at the macro level. The aim here is the production of demonstrators taking into account the results at the atomic level, which, for example, require sealing against the graphite exit to ensure a certain water content in the bearing. The influence of the investigations at the micro level is achieved, for example, by taking into account a certain surface roughness that favors transfer layer formation.
DFG Programme
Priority Programmes
