简介: |
The effects of capillarity on the microscale, which are caused by the presence of thin water layers on almost all types of surfaces, are well documented in numerous reports in literature. Also known is the fact that the detrimental effects of these thin water films can be reduced by using hydrophobic coatings. These coatings can be achieved by chemically altering the surface. Another method is to structure the surface, thereby reducing the real contact area. This presentation illustrates the effects of chemical composition and surface roughness in the μN force regime by presenting three case studies using a microtribometer: The first involves self-assembled monolayers to show the effect of chemical composition. The second discusses the effect of surface roughness using titanium carbide under self-mating conditions as an example. The third combines the two effects of chemical composition of the surface and surface roughness by examining surfaces that are nanostructured as well as chemically altered. A brief mention of other tribosystems will also be presented. This work shows that much work is still needed to be able to predict the optimum topography leading to low friction for particular contact situations.
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