3050 Observation by AFM for Boundary Friction under Low Speed and Low Contacting Pressure Conditions
Details
Very low boundary friction coefficient less than 0.01 appears if a lubricant containing alkyl acid phosphate is employed under low speed and low contacting pressure condition. In order to elucidate the effect of the alkyl acid phosphate on this very low friction, microscopic observations of a well-running-in surface by atomic force microscopy are conducted. From the FFM results by a cantilever of which tip is replaced by a glass sphere with 40μm of the diameter, it is found that reaction layers on well-running-in surface, which mainly consist of iron phosphate, has some effect but decisive factor on the low friction in this situation. Since, even in the case of the polished surface, alkyl acid phosphate exhibits a large effect on lower and more stable friction, the low friction may be mainly brought about by thick adsorbed layers of the alkyl acid phosphate.
