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 influenc… Show more
“…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].…”
Abstract:In this experimental investigation the laser surface texturing of tool steel of type 90MnCrV8 has been conducted. The 5-axis highly dynamic laser precision machining centre Lasertec 80 Shape equipped with the nano-second pulsed ytterbium fibre laser and CNC system Siemens 840 D was used. The planar and spherical surfaces first prepared by turning have been textured. The regular array of spherical and ellipsoidal dimples with a different dimensions and different surface density has been created. Laser surface texturing has been realized under different combinations of process parameters: pulse frequency, pulse energy and laser beam scanning speed. The morphological characterization of ablated surfaces has been performed using scanning electron microscopy (SEM) technique. The results show limited possibility of ns pulse fibre laser application to generate different surface structures for tribological modification of metallic materials. These structures were obtained by varying the processing conditions between surface ablation, to surface remelting. In all cases the areas of molten material and re-cast layers were observed on the bottom and walls of the dimples. Beside the influence of laser beam parameters on the machined surface quality during laser machining of regular hemispherical and elipsoidal dimple texture on parabolic and hemispherical surfaces has been studied.
“…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].…”
Abstract:In this experimental investigation the laser surface texturing of tool steel of type 90MnCrV8 has been conducted. The 5-axis highly dynamic laser precision machining centre Lasertec 80 Shape equipped with the nano-second pulsed ytterbium fibre laser and CNC system Siemens 840 D was used. The planar and spherical surfaces first prepared by turning have been textured. The regular array of spherical and ellipsoidal dimples with a different dimensions and different surface density has been created. Laser surface texturing has been realized under different combinations of process parameters: pulse frequency, pulse energy and laser beam scanning speed. The morphological characterization of ablated surfaces has been performed using scanning electron microscopy (SEM) technique. The results show limited possibility of ns pulse fibre laser application to generate different surface structures for tribological modification of metallic materials. These structures were obtained by varying the processing conditions between surface ablation, to surface remelting. In all cases the areas of molten material and re-cast layers were observed on the bottom and walls of the dimples. Beside the influence of laser beam parameters on the machined surface quality during laser machining of regular hemispherical and elipsoidal dimple texture on parabolic and hemispherical surfaces has been studied.
“…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.…”
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confidence: 62%
“…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.…”
This study investigates the effects of the micro-dimple texture on the friction and surface temperature performances of a ball-on-disk contact, operating under the speed and load ranges that cover typical gearing applications. Circular shaped micro-dimple arrays with different dimple center distances and dimple depths are implemented on the ball surface to quantify the impacts of these two parameters on the friction coefficient and the maximum ball surface temperature. In addition, the contacts of three surface texture combinations, namely micro-dimpled and polished ball surface versus polished disk surface, polished ball surface versus polished disk surface and ground ball surface versus ground disk surface, are compared to demonstrate any beneficial or detrimental effect of micro-dimples in heavily loaded high speed applications. This study adopts a thermal mixed EHL point contact model, whose capability and accuracy have been well demonstrated by comparing to the experimental measurements, to quantify the deterministic tribological behavior within the contact, allowing the exploration of the underlying mechanism that governs the role of micro-dimples in the elastohydrodynamic lubrication.iv
“…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.…”
Abstract. In this study, the effect of triangular dimple orientation on load-carrying capacity is further investigated. The effect of geometric and operating parameters including the area ratio, the depth, the angular speed and the film thickness on load-carrying capacity is discussed under different orientation angles. The load-carrying mechanisms of the triangular dimples is analyzed.
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