A Scale Dependent Simulation of Liquid Lubricated Textured Surfaces

Abstract

Over the past few years, the importance of nanoscale technology in industries, such as data storage, micro-electro-mechanical systems (MEMs), and conventional sliding and rolling element bearings, has increased significantly. This is due to increased performance criteria and emerging technologies at smaller scales. One way to increase tribological performance of such applications is through nanoscale surface texturing. These textures will allow for precise control of the performance of lubricated surfaces with very thin films. This work examines how the behavior of the lubricant changes as the geometry of the texture is decreased toward the nanoscale. This work uses existing scale dependent lubrication theories to model the hydrodynamic lubrication of textured surfaces in attempt to predict how nanoscale textures will perform. The theoretical results show that the scale effects of a lubricant between textured surfaces can decrease the load carrying capacity while also decreasing the friction force. Overall, the friction force decreases more than the load carrying capacity and so the effective friction coefficient is decreased. It should be noted that relative to larger scale textured surfaces, the load support can also decrease with the decreasing scale of the texture.