Evaluation of the real contact area in three-body dry friction by micro-thermal analysis
Evaluation of the real contact area in three-body dry friction by micro-thermal analysis
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DOI：
10.1016/j.triboint.2009.12.001
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发表时间：
2010-10
影响因子：
6.2
通讯作者：
P. Stempfle;Olivier Pantalé;Toufik Djilali;R. K. Njiwa;X. Bourrat;J. Takadoum
中科院分区：
文献类型：
--
作者：
P. Stempfle;Olivier Pantalé;Toufik Djilali;R. K. Njiwa;X. Bourrat;J. Takadoum
发生在微米和纳米级上的许多摩擦学特性和磨损机制受到所谓的真实的接触面积（Ar）的强烈控制，该面积是名义或表观接触面积（Aa）的一小部分。阿里斯的确定通常基于（i）描述接触表面的真实的几何形状的几何方法或（ii）涉及接触力学和物理机械性质的机械方法。此外，也尝试了一些实验方法，但它们通常不考虑界面处存在的第三体，即捕获在接触内的磨损碎屑。本文提出了一种由工作参数（Fn，v，T）和存在第三体时的摩擦学响应（μ，Ft）估算动态真实的接触面积的实验方法。扫描热显微镜（SThM）用于确定第三体的热导率以及接触温度与在微粗糙度水平处真正耗散的热功率之间的关系。这些结果与宏观摩擦接触的热模型相结合，用于计算真实的接触面积和真实的接触压力。验证这些结果进行了使用一个经典的格林伍德威廉姆森模型和有限元模型建立从真实的AFM地图。
Many tribological properties and wear mechanisms occurring on the micro-and nanoscale are strongly controlled by the so-called real contact area (Ar) which is a small fraction of the nominal or apparent contact area (Aa). The determination of Aris often based on either (i) a geometrical approach describing the real geometry of contacting surfaces or (ii) a mechanical approach involving contact mechanics and physical-mechanical properties. In addition some experimental methods have also been attempted but they generally do not take into account the presence of third body at the interface—i.e. the wear debris trapped within the contact. In this paper we propose an experimental approach to estimate the dynamic real contact area from the operating parameters (Fn, v, T) and the tribological responses (μ, Ft) in presence of third body. A scanning thermal microscope (SThM) is used for determining both the thermal conductivity of the third body and the relationship between the contact temperature and the thermal power really dissipated at the micro-asperity level. These results are combined with a thermal model of the macro-tribocontact for computing the real contact area and the real contact pressure. Validation of these results is carried out using a classical Greenwood Williamson model and finite element models built from the real AFM maps.