Project V – Nanostructuring and Nanohydrodynamics:
Experiments and Simulations related to automotive parts

Contributors: M.Scherge, M.Schöne, E.Meyer

Experiments carried out with automotive parts (cylinder liner/piston ring) revealed that the tribological performance is determined by the material properties of the first one hundred nanometers. This involves chemical and structural changes induced by the mechanical interaction of both solids. In addition, topography changes accordingly. Common procedures to measure topography as for instance stylus profilometry provide values such as average roughness or its standard deviation. These values do not characterize the surface sufficiently since nanometric influences are neglected. Although the systems are macroscopic, properties as for instance wetting can only be understood on the nanometer level. Therefore, force microscopy (lateral, chemical ...) can provide a good tool to study atomic mechanisms of lubricant spreading, lubricant reflow after impact and lubricant behavior under confinement. Furthermore, the impact of many additives on friction and wear is poorly understood. Not only the attachment of the molecules to the solid surface but also ordering phenomena inside the lubricant are of main interest. Another interesting field is the nanostructure of the material. Are there any structures that prevent wetting (lotus effect) or allow better wetting of the solid by hydrocarbons? Can nanostructuring boost micro- or nanohydrodynamics? How mechanically stable are adsorbed oil layers (force-distance-curves).