Regensburg 2013 – scientific programme
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O: Fachverband Oberflächenphysik
O 9: Nanotribology
O 9.4: Talk
Monday, March 11, 2013, 11:15–11:30, H42
Correlating contact area and friction of laser-textured surfaces — •Nikolay Prodanov1,2 and Martin H. Müser1,2 — 1Department of Materials Science and Engineering, Saarland University, Campus 66123 Saarbrücken, Germany — 2Jülich Supercomputing Centre, Institute for Advanced Simulation, FZ Jülich, Jülich, Germany
Laser surface texturing (LST) is a technique for producing surfaces with a sinusoidal topography. We conduct numerical contact mechanics simulations, which are based on experimentally determined height profiles, to investigate how the kinetic friction of such surfaces is related to the real contact area.
The Green's function molecular dynamics method is used in the calculations. Surface topographies of a flat steel substrate and a bearing ball are used. The periodicity of the grooves is 9 and 18 microns. Parallel and perpendicular relative orientations of the grooves are considered. To ascertain the effect of the roughness on different length scales, we use Gaussian or Fourier smoothing of the original topographies. The dependencies of the relative contact area and of the contact pressure distribution on load, relative orientation and smoothing are obtained. The contact area is very sensitive to the spatial resolution of the topographies. The ratio of the value of real contact area at the two orientations is insensitive to smoothing. The experimental differences for the kinetic friction are similar in magnitude to those for the relative contact area. The contact pressure distribution is not sensitive to changes in the normal forces and orientations of the surfaces. Changing the resolution considerably affects the distribution.