Experimental investigation and a model to predict the steady-state friction coefficient in the lubricated contact

INTRODUCTION The mechanical and tribological properties of materials can be studied at different scales of Nano [1-10], meso [11-13], and micro [14-17]. As the scale goes down, the accuracy increases while the length and time scale which is possible to be simulated decreases. Here, a model is developed to capture the friction coefficient in the lubricated contact in the pin on disk experiment. Since both the lubricant film and the surface asperities are playing non negligible role in load carrying, the load-sharing concept is incorporated to develop the model. First, the equivalent radius of the contact surface is obtained. Next, the separation between two surfaces which are in contact is calculated. The dimensionless lubricant thickness is then obtained. The lubricant force and shear stress is obtained assuming the Newtonian behavior. Finally, the results are compared to the experiments presented in [17].