A Quantitative Friction-Based Approach of the Limiting Shear Stress Pressure and Temperature Dependence

A Quantitative Friction-Based Approach of the Limiting Shear Stress Pressure and Temperature... Friction in highly loaded lubricated contacts (where the pressure is greater than 1 GPa) may present a plateau at intermediate slide-to-roll ratio, known in the literature as the limiting shear stress (LSS) plateau. Its physical origins and its dependence to the operating conditions are still unclear, that is why predicting friction in such contacts still remains an issue. Apart from the nature of the lubricant, the two main parameters influencing the friction plateau value are pressure and temperature. The literature provides several empirical expressions of the LSS which either consider the pressure influence only, or both pressure and temperature but almost always with coupled terms. Therefore, the published LSS values derived from friction measurements can be considered as the macroscopic consequence of the influence of pressure and temperature but also of shear heating that occurs in sliding highly loaded contacts. In this paper, the contribution of each parameter was studied separately, i.e. through experiments accrued out under nominal isothermal conditions, but conducted at different temperatures and pressures on two lubricants: a synthetic ester (benzyl benzoate) and a turbine mineral oil. A new LSS model was derived, based only on the mechanical (i.e. shear) contribution to the LSS. Surprisingly, a simple linear dependence of the LSS with both pressure and temperature was found, revealing that the influence of each of the two parameters is decoupled from the other. As far as we know, this is the first time that such an uncoupled LSS model in pressure and temperature is reported. This work offers a better quantification of the response of lubricants submitted to very high pressure and high shear: it should help to improve friction prediction in highly loaded lubricated contacts. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Tribology Letters Springer Journals

A Quantitative Friction-Based Approach of the Limiting Shear Stress Pressure and Temperature Dependence

Loading next page...
 
/lp/springer_journal/a-quantitative-friction-based-approach-of-the-limiting-shear-stress-Cu193Ik0Kz
Publisher
Springer US
Copyright
Copyright © 2017 by Springer Science+Business Media, LLC
Subject
Materials Science; Tribology, Corrosion and Coatings; Surfaces and Interfaces, Thin Films; Theoretical and Applied Mechanics; Physical Chemistry; Nanotechnology
ISSN
1023-8883
eISSN
1573-2711
D.O.I.
10.1007/s11249-017-0929-2
Publisher site
See Article on Publisher Site

Abstract

Friction in highly loaded lubricated contacts (where the pressure is greater than 1 GPa) may present a plateau at intermediate slide-to-roll ratio, known in the literature as the limiting shear stress (LSS) plateau. Its physical origins and its dependence to the operating conditions are still unclear, that is why predicting friction in such contacts still remains an issue. Apart from the nature of the lubricant, the two main parameters influencing the friction plateau value are pressure and temperature. The literature provides several empirical expressions of the LSS which either consider the pressure influence only, or both pressure and temperature but almost always with coupled terms. Therefore, the published LSS values derived from friction measurements can be considered as the macroscopic consequence of the influence of pressure and temperature but also of shear heating that occurs in sliding highly loaded contacts. In this paper, the contribution of each parameter was studied separately, i.e. through experiments accrued out under nominal isothermal conditions, but conducted at different temperatures and pressures on two lubricants: a synthetic ester (benzyl benzoate) and a turbine mineral oil. A new LSS model was derived, based only on the mechanical (i.e. shear) contribution to the LSS. Surprisingly, a simple linear dependence of the LSS with both pressure and temperature was found, revealing that the influence of each of the two parameters is decoupled from the other. As far as we know, this is the first time that such an uncoupled LSS model in pressure and temperature is reported. This work offers a better quantification of the response of lubricants submitted to very high pressure and high shear: it should help to improve friction prediction in highly loaded lubricated contacts.

Journal

Tribology LettersSpringer Journals

Published: Oct 11, 2017

References

You’re reading a free preview. Subscribe to read the entire article.


DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Search

Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly

Organize

Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.

Access

Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

DeepDyve

Freelancer

DeepDyve

Pro

Price

FREE

$49/month
$360/year

Save searches from
Google Scholar,
PubMed

Create lists to
organize your research

Export lists, citations

Read DeepDyve articles

Abstract access only

Unlimited access to over
18 million full-text articles

Print

20 pages / month

PDF Discount

20% off