Geometric Shape Effects of Surface Texture on the Generation of Hydrodynamic Pressure Between Conformal Contacting Surfaces

Abstract

Micro-surface texturing design is becoming an important part of surface engineering since engineering practices and analyses have indicated that surface textures may significantly affect the tribological performance of contact interfaces. Advances in the manufacturing technologies of surface finishing and micro-machining, such as laser surface texturing, photolithography, and etching, LIGA process, have made it possible to fabricate different fine structures on various engineering surfaces. Though the influence of micro-surface texturing on hydrodynamic lubrication has been widely investigated over the last decade, such an influence may be complicated and difficult to characterize with only a few statistic surface parameters. Thus, very little attention has been paid to the effects of different textural shapes and orientations on hydrodynamic lubrication, which is the main topic of this article. A theoretical model based on a single dimple was established to investigate the geometric shape and orientation effects on the hydrodynamic pressure generated between conformal contacting surfaces. Using the Successive Over Relaxation method, the average hydrodynamic pressure generated by the texture pattern with the dimples in shapes of circle, ellipse, and triangle at different orientations to the direction of sliding are obtained. The results indicate that geometric shape and orientation have obvious influences on load-carrying capacity of contacting surfaces. With the same dimple area, area ratio and dimple depth given in this research, ellipse dimples perpendicular to the sliding direction showed the best load-carrying capacity. This result agrees with previous experimental results very well.

Laser surface texturing of tool steel: textured surfaces quality evaluation

“…Several classes of tribological experiments were developed in order to investigate the benefits of laser surface texturing in term of reduction of friction coefficients and reduction of wear rates, mainly on steel surfaces [11][12][13][14][15]. But there is a lack of information about the interaction between laser beam and material structure and the laser beam, which plays a key role in the formation of dimples of required shapes and surface integrity [16].…”

The Effects of Microdimple Texture on the Friction and Thermal Behavior of a Point Contact

“…The results showed the effects of the dimple size and density on the friction reduction were similar to those under the low loading condition [23][24][25]29]. The shape of the dimple, however, was found to have negligible impact on the friction, contradicting the findings of Galda et al [25] and Yu et al [30] where the loads were much lower. Instead of relying on the experimental measurements, Meng et al [34] numerically simulated the friction behavior of parallel surfaces, and found that the effectiveness of micro-dimples on the friction reduction was dependent on both the operating condition and the surface roughness condition.…”

“…Tang et al [29] demonstrated the strong influence of the adjacent dimple interactions on the hydrodynamic pressure. Yu et al [30] found the geometric shapes and orientations of dimples have an evident impact on the load-carrying capacity, while considering a single dimple instead of a dimple array on the surface. Brunetiere and Tournerie [31] simulated the hydrodynamic lift mechanism of a mechanical seal with textured surfaces, pointing to the importance of the dimple geometry and density in the friction reduction.…”

The Effect of Triangular Dimple Orientation on Load-Carrying Capacity

“…Siripuram et al [15] carried out to numerically studied to find that the effect of the triangular dimple orientation on the leakage. Yu et al [16] carried out theoretical studies to investigate the effect of the triangular dimple orientation on the hydrodynamic pressure. Xie et al [17] have investigated tribological performance of triangular dimples in water lubrication by experimental methods.…”