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Abstract: Mixed lubrication in the nano-scale is discussed, which is
constituted from dry friction, boundary lubrication, thin film
lubrication. A dynamic contact ratio which is the contact ration
measured in the rolling process is used to describe the nano-mixed
lubrication, and the relationship between the contact ratio and its
influence factors is investigated. Experimental results indicate that
the dynamic contact ratio increases with the decrease of thin film
thickness by an exponential function. The decreases of speed and
lubricant viscosity, and the increase of loads will enlarge the value of
the contact ratio. When polar additives are added into basic oil, the
contact ratio decreases. In addition, the contact ratio between smooth
surfaces is larger than that between rough surfaces in lower speed.
However, the contact ratio between smooth surfaces decreases more
quickly with speed than that between rough surfaces, and therefore, it
will become smaller than that of rough surfaces after speed increases
over a critical value.
Key words: Mixed lubrication Nano-tribology Thin film lubrication
CLC No: TH117
国家自然科学基金和杰出青年基金资助项目.
Received 20011108, received in revised form 20020708
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