Influence of anisotropic surface roughness on lubricated rubber friction: Extended theory and an application to hydraulic seals

Abstract The authors of the research have analysed spacing parameters of anisotropic 3D surface roughness crosswise to machining (friction) traces RSm1 and lengthwise to machining (friction) traces RSm2. The main issue arises from the RSm2 values being limited by values of sampling length l in the measuring devices; however, on many occasions RSm2 values can exceed l values. Therefore, the mean spacing values of profile irregularities in the longitudinal direction in many cases are not reliable and they should be determined by another method. Theoretically, it is proved that anisotropic surface roughness anisotropy coefficient c=RSm1/RSm2 equals texture aspect ratio Str, which is determined by surface texture standard EN ISO 25178-2. This allows using parameter Str to determine mean spacing of profile irregularities and estimate roughness anisotropy.

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Anisotropic Surface Roughness in Strain Relaxed In0.40GA0.60As on Gaas with a Step-Graded InxGA1-xAs Buffer Layer

MRS Proceedings ◽

10.1557/proc-312-107 ◽

1993 ◽

Vol 312 ◽

Cited By ~ 2

Author(s):

J. C. P. Chang ◽

B. K. Kad ◽

S. R. Nutt ◽

K. L. Kavanagh

Keyword(s):

Electron Microscopy ◽

Surface Roughness ◽

Buffer Layer ◽

Strain Relaxation ◽

Phase Segregation ◽

Periodic Variation ◽

Cross Sectional ◽

Anisotropic Surface ◽

Transmission Electron ◽

Plane Direction

AbstractWe report the structural characterization of the 3-D relaxation morphology of In0.4Ga0.6As grown on a step-graded InxGa1-xAs buffer layer on GaAs. Scanning electron microscopy showed “grooves” spaced on the order of microns running only in the [110] direction. Each groove was observed with cross-sectional transmission electron microscopy to mark the location of a vertical low-angle tilt and/or twist boundary. The veiy rough layer morphology may be the result of island coalescence or severe surface roughness that created the grain boudnaries as the layer grew. Strain relaxation in the In0.4Ga0.6As layer was much reduced in the [101] in-plane direction. The asymmetry in residual in-plane strains in the In0.3Ga0.7AS layer and/or the increased In composition may be responsible for the development of an anisotropic surface roughness. X-ray microanalysis revealed a periodic variation in layer composition which correlated with a fine contrast modulation presumably the result of phase segregation.

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Synergistic friction-reducing effects between the transverse direction of anisotropic surface roughness and the high-density adsorbed films under a boundary lubrication regime

Tribology International ◽

10.1016/j.triboint.2012.10.003 ◽

2013 ◽

Vol 58 ◽

pp. 98-106 ◽

Cited By ~ 7

Author(s):

Saiko Aoki ◽

Daisuke Fukada ◽

Yuki Yamada ◽

Akihito Suzuki ◽

Masabumi Masuko

Keyword(s):

Surface Roughness ◽

Boundary Lubrication ◽

Transverse Direction ◽

High Density ◽

Anisotropic Surface ◽

Adsorbed Films ◽

Lubrication Regime ◽

Friction Reducing

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Anisotropic resistivity of thin films due to quantum electron scattering from anisotropic surface roughness

Journal of Vacuum Science & Technology A Vacuum Surfaces and Films ◽

10.1116/1.2699254 ◽

2007 ◽

Vol 25 (2) ◽

pp. 330-333 ◽

Cited By ~ 3

Author(s):

M. C. Salvadori ◽

M. Cattani ◽

F. S. Teixeira ◽

R. S. Wiederkehr ◽

I. G. Brown

Keyword(s):

Thin Films ◽

Surface Roughness ◽

Electron Scattering ◽

Anisotropic Surface ◽

Quantum Electron

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FE Prediction of Hysteretic Component of Rubber Friction

Advances in Tribology ◽

10.1155/2012/807493 ◽

2012 ◽

Vol 2012 ◽

pp. 1-12 ◽

Cited By ~ 2

Author(s):

L. Pálfi ◽

T. Goda ◽

K. Váradi ◽

E. Garbayo ◽

J. M. Bielsa ◽

...

Keyword(s):

Surface Roughness ◽

Storage Modulus ◽

Viscoelastic Material ◽

Loss Factor ◽

Master Curve ◽

Reaction Force ◽

Maxwell Model ◽

Material Models ◽

Rubber Friction ◽

Maxwell Models

The hysteretic part of the friction coefficient for rubber sliding on an ideal rigid, rough surface has been investigated by FE technique. The FE models were created by using two different FE softwares, ABAQUS and MSC.MARC. The surface roughness has been considered by using two different sine waves having a wavelength of 100 μm and 11.11 μm, as well as their superposition. Parameters of the viscoelastic material models of the rubber were gained, firstly from a fit to the measured storage modulus, secondly from a fit to the measured loss factor master curve of the rubber. The effect of viscoelastic material models, comparing 10-term and 40-term generalized Maxwell models was also considered together with the temperature effect between −50 and150°C. According to the results, both postprocessing methods, namely, the reaction force and the energy-based approach, show very similar coefficients of friction. The 40-term Maxwell model fitted to both the storage modulus and loss factor curve provided the most realistic results. The tendency of the FE results has been explained by semianalytical theory.

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