Structure Evolution in Tribological Interfaces Studied by Multilayer Model Alloys

During sliding of surfaces the near surfaces undergo significant changes in terms of topography, composition and microstructure and a so-called “third body” or “tribomaterial” forms which differs strongly from the bulk materials in terms of topography, composition and microstructure. This has been studied in a series of experiments using different metals sliding against metal, ceramics or coatings. In this work we use multilayer model alloys of an Au/Ni layer system to study effects of grain size on steady-stady friction by varying the layer spacing and the number of layers. Using microtribometer under ultra-high-vacuum conditions, we performed friction experiments sliding with a ruby sphere against Au/Ni multilayers. We find that the friction strongly depends on the layer spacing, and we are able to link the friction to the tribologically induced tribomaterial as found by FIB and TEM/EDS.