Efficiency of surface texturing in the reducing of wear for tests starting with initial point contact

Abstract

Surface texturing can change the friction and wear properties of the material surface. It shows outstanding performance in reducing friction coefficients and wear in conformal flat contact. However, during initial point contact, most studies have found that it reduces the friction coefficient and increases wear. In this paper, ball-on-disc sliding tests were conducted to verify whether surface texturing could reduce wear of silicon nitride sliding in water for tests starting with initial point contact. The effects of texture parameters (depth, textured area, and diameter) were studied. Results showed that most textures could reduce Si3N4 wear after running-in process. Multi-scale texture, which was combined with large (11 μm depth, 2% textured area, and 22 μm diameter) and small (5 μm depth, 1% textured area, and 15 μm diameter) textures, could reduce the wear by 93% and increase the bearing capacity by 244%. Comparative experiments of oil and water lubricants were carried out to explore the mechanism of texture reducing wear in the running-in process, and two competitive mechanisms of hydrodynamic effect and stress concentration were found. This work provides a practical foundation for optimizing texture design and reducing wear of ceramic materials under water lubrication.