Abstract In this study, the effect of grain boundary on the frictional behavior under the oil-lubricated condition was investigated by varying the grain size (crystallite size) of the pure Fe samples prepared via physical vapor deposition. A high fraction of grain boundary in the sample yielded a low friction coefficient μ in the case of a lubrication oil that formed a chemisorbed film on the surface of the material. Thick absorbed layer formed on the surface was observed only in the sample with high fraction of grain boundary. These results indicate that a disordered structure in the vicinity of grain boundary preferentially forms chemisorbed films and reduces μ by protecting the surface of the material.

中文翻译：

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油润滑下晶界对纯铁摩擦系数的影响

摘要 在本研究中，通过改变物理气相沉积法制备的纯铁样品的晶粒尺寸（晶粒尺寸），研究了晶界对油润滑条件下摩擦行为的影响。在润滑油在材料表面形成化学吸附膜的情况下，样品中高比例的晶界产生低摩擦系数 μ。仅在具有高晶界分数的样品中观察到在表面上形成的厚吸收层。这些结果表明，晶界附近的无序结构优先形成化学吸附膜，并通过保护材料表面来降低 μ。