Recent development on surface texturing in enhancing tribological performance of bearing sliders

Abstract

Surface texturing is a surface modification approach, resulting in an improvement in tribological performance such as friction and wear resistance. Surface texturing can be performed either as a protruded or recessed asperity, with the latter being more popular due to advantages in terms of micro-lubrication and ease of manufacturing. There are a number of ways of material preparation for surface texturing, with the laser surface texturing being the most popular because of its flexibility and high accuracy. The performance of textured surface depends on the geometrical characteristics of the surface texture and the operating condition of the bearing components. In hydrodynamic and mixed lubrication, microcavity in negative surface texture acts as a reservoir for fluid lubricant, while in boundary lubrication, it traps wear particles to reduce further abrasion. In the past, tremendous amount of research effort has been put into the study of surface texturing, with an aim to investigate the underlying effect of surface texturing on tribological performance. This paper presents a critical review of research and development on surface texturing over the past decades, highlighting design, optimization and fabrication of surface texture, and their effects on tribological performance in terms of friction and load bearing capacity under different lubrication regimes. Numerical modelling approaches involving Reynolds and Navier–Stokes equations employed to understand and determine the tribological behaviour are discussed and compared with respect to experimental investigations. Thin film coatings on textured surface have been found to be a promising means to further reduce friction and increase wear life.