We report experimental measurements of friction between an aluminum alloy sliding over steel with various lubricant densities. Using the topography scans of the surfaces as input, we calculate the real contact area using the boundary element method and the dynamic friction coefficient by means of a simple mechanistic model. Partial lubrication of the surfaces is accounted for by a random deposition model of oil droplets. Our approach reproduces the qualitative trends of a decrease of the macroscopic friction coefficient with applied pressure, due to a larger fraction of the micro-contacts being lubricated for larger loads. This approach relates direct measurements of surface topography to realistic distributions of lubricant, suggesting possible model extensions towards quantitative predictions.

我们报告了铝合金在具有各种润滑剂密度的钢上滑动之间摩擦的实验测量。使用表面的地形扫描作为输入，我们使用边界元法和动摩擦系数通过简单的机械模型计算实际接触面积。表面的部分润滑由油滴的随机沉积模型解释。我们的方法再现了宏观摩擦系数随施加压力下降的定性趋势，因为较大的微接触部分被润滑以承受更大的负载。这种方法将表面形貌的直接测量与润滑剂的实际分布联系起来，表明可能的模型扩展到定量预测。