Effectiveness and design of surface texturing for different lubrication regimes

Podgornik, Bojan; Vilhena, Luís; Sedlaček, Marko; Rek, Zlatko; Žun, Iztok

doi:10.1007/s11012-012-9540-7

Cited by 121 publications

(61 citation statements)

References 29 publications

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“…Most experiments were conducted with traditional tribometers (unidirectional pinon-disc [11][12][13][14][15][16] or reciprocating sliding [17][18][19][20][21][22][23][24] tests), while other studies were conducted on real components, including journal bearings [25] thrust bearings [26][27][28] and mechanical seals [29][30][31]. To date, various surface texturing techniques have already been introduced, such as laser surface texturing (LST); reactive ion etching (RIE); embossing technique; "Lithographie, Galvanoformung, Abformung" (LIGA) process; abrasive jet machining (AJM), electrolytic etching, and so on.…”

Section: Introductionmentioning

confidence: 99%

A Novel Surface Texture Shape for Directional Friction Control

Lu¹,

Wood²,

Gee

et al. 2018

Tribol Lett

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An experimental study is presented to evaluate the influence of anisotropically shaped textures on the behaviour of sliding friction and sensitivity to sliding direction. The plate samples were textured with triangular sloped dimples using an ultrafast laser surface texturing technique. Reciprocating cylinder-on-plate tests were conducted with steel sliding pairs using mineral base oil as a lubricant to compare the tribological performance of reference non-textured specimen and dimpled samples. The dimples were designed with varying converging angles in the transverse y-z plane and top-view x-y plane. In this study, no dimple was fully covered in the contact area since the dimples size is much larger than the Hertzian line contact width. Stribeck style dynamic friction curves across boundary, mixed and hydrodynamic lubrication regimes were used to determine the benefit or antagonism of texturing. Observation of the directional friction effect of the anisotropic textures indicated that the converging shapes are beneficial for friction reduction, and the dimpled specimens have a lower friction coefficient particular under prevailing boundary lubrication conditions. It was also found that the real contact length variation rate is a major factor controlling the local friction response. The sloped bottoms of the textures produce effective converging wedge action to generate hydrodynamic pressure and contribute to the overall directional friction effects.

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Section: Introductionmentioning

confidence: 99%

A Novel Surface Texture Shape for Directional Friction Control

Lu¹,

Wood²,

Gee

et al. 2018

Tribol Lett

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“…Basic models for various applications, like journal bearings [6], mechanical seals [7], thrust bearings [8] and cylinder liners [9], have been built to find the optimal texture designs. In the meantime, a significant number of experimental studies have been conducted using both traditional tribometers (unidirectional pin-on-disc [10][11][12][13][14] or reciprocating sliding [15][16][17][18][19] test set-up) and real components (including journal bearings [20] thrust bearings [21][22][23] and mechanical seals [24]). For the textured surface in terms of friction and wear reduction, the following mechanisms were proposed to explain the phenomenon observed in the experimental tests: 1.…”

Section: Introductionmentioning

confidence: 99%

The use of anisotropic texturing for control of directional friction

Lu¹,

Wood²,

Gee

et al. 2017

Tribology International

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This paper presents a study on the influence of anisotropically shaped texture arrays on friction behaviour of an oil lubricated sliding contact, especially on directional friction control based on the diverging and converging characteristics of the textures. Experiments have been conducted on a TE77 reciprocating cylinder-on-plate test rig, where steel rollers were used to slide against steel plate samples with or without textures. A mineral base oil was used to lubricate the contacts. Three geometries of dimples were designed and laser textured on the steel plate samples with varied 3-dimensional features, including Square Flat (SF), Square slope (SS) and Triangular Flat (TF) shapes representing the shape in x-y (top view) and x-z (side view) planes respectively. These shapes were chosen to vary the converging and diverging properties of the lubricated contacts depending on the sliding direction. Relatively large dimple sizes (side length ~ and depth ~ ) have been used in this study to enable observation of the effect and easy control of the texturing process. The texture density has been kept at as most literature suggested. The large dimple sizes resulted that the dimples were not be fully covered by the contact area, i.e. the dimple sides were bigger than the Hertzian contact width of the roller-flat contacts. This has eliminated the 'lift' or 'load bearing' effect discussed in most papers thus focuses on other effects investigated in this study. The results show that beneficial effects of the anisotropic textures present in all lubrication regimes including the boundary, mixed and hydrodynamic lubrications, especially under prevailing boundary lubrication conditions. Using high sampling rate for the friction data during the tests, it was able to study local friction effect due to individual dimple array especially at their leading and trailing edges. The results show that a local friction reduction is observed at the leading while an increase at the trailing edge. Overall directional friction effect of the anisotropic textures has been observed that the converging shape in both y-z plane and the x-y plane reduces friction. Furthermore, it was found that the triangular shape dimples have a greater local frictional response at each dimple array, while the sloped bottom square dimples have a more significant overall directional fricition effect.

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“…There is an increasing demand for improved performance and reliability of mechanical systems that use advanced materials and surface-engineering techniques, which would increase efficiency, conserve scarce material resources and reduce energy losses through reduction of friction [1][2][3].…”

Section: Introductionmentioning

confidence: 99%