接触領域のその場観測によるナノ厚さ液体膜の潤滑メカニズム解明

抄録

A high-performance interference microscope was integrated with a previously developed pin-on-disk type friction tester. This allows us to in situ observe the contact region between the pin and disk mediated with nanometer-thick liquid lubricant films, and to measure the sliding-induced vertical displacement of the pin with subnanometer resolution. Our experimental results showed that the vertical displacement of the sliding pin rapidly increased with respect to the sliding speed and then saturated. The saturation value increased with increasing thickness and viscosity of the liquid lubricant films. We also observed changes in the flow behavior of the lubricant films depending on the sliding speed. From these results, we infer that nanometer-thick liquid lubricant films can generate upward hydrodynamic pressure and exhibit behavior like fluid lubrication.