Abstract In greased contacts, the complex rheology of a grease, depending on thickener, base oil and additives, becomes a key point for understanding and controlling the evolution of friction coefficient at extremely low sliding velocities. Such velocity range (from 0 to few mm/s) is of main relevance for several issues, such as unstable friction-induced vibrations, which can occur as well in the case of lubricated interfaces. In this paper, a greased contact at low sliding velocities is then reproduced and analysed on a dedicated tribometer, under well controlled boundary conditions. Static and dynamic friction coefficients, as function of velocity, are obtained, considering either dry and lubricated contact, with both the grease and its base oil. The effect of DLC surface coating is analysed too. The contributions of the lubricant components on the frictional and dynamic response have been then discussed, showing a non-trivial trend of friction, with respect to speed, within the investigated velocity range.

中文翻译：

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“低滑动速度条件下润滑接触的摩擦行为”

摘要 在润滑脂接触中，取决于稠化剂、基础油和添加剂的润滑脂的复杂流变学成为理解和控制极低滑动速度下摩擦系数演变的关键点。这种速度范围（从 0 到几毫米/秒）与几个问题密切相关，例如不稳定的摩擦引起的振动，在润滑界面的情况下也会发生这种情况。在本文中，然后在良好控制的边界条件下，在专用摩擦计上再现和分析低滑动速度下的润滑接触。考虑与润滑脂及其基础油的干接触和润滑接触，获得作为速度函数的静摩擦系数和动摩擦系数。也分析了DLC表面涂层的效果。