Advertisement

Journal of Mechanical Science and Technology

, Volume 33, Issue 11, pp 5361–5368 | Cite as

Role of additive concentration in slow-speed sliding contact under boundary lubrication conditions

  • Bora Lee
  • Yonghun Yu
  • Dae-Seung Cho
  • Yongjoo ChoEmail author
Article

Abstract

The adsorption model for boundary lubrication was proposed considering the variations of additive content with sliding distance. With surface roughness and wear debris caused by the adhesive wear of the oxide layer, a mass conservation of additive dissolved in lubricant was established. Any rise in surface temperature due to sliding friction was ignored for this study’s purposes. It was found that the additive concentration decreased rapidly with sliding distance because wear particles adsorbed and consumed the additives. This reduction of the additive concentration raised the friction coefficient by reducing the surface area protected by the adsorption layer without any temperature effect. This analysis model was verified by comparing it with the test results of existing literature. Because this model is effective at extremely low-speed conditions, these results can help explain the failure mechanism in room-temperature, lowspeed boundary lubrication.

Keywords

Additive concentration Adsorption Boundary lubrication Film defect Low speed 

Nomenclature

Aw0

Surface area of a wear particle

c

Additive concentration

Cmf

Additive concentration in mole fraction

E

Heat of adsorption

f0

Fraction of oxygen in the oxide layer

km

Wear coefficient for solid-solid contact

Ns

Total number of adsorption sites per area

The number of wear particles per unit volume

Pn

Average contact pressure

Pm

Flow pressure under static loading

Q

Activation energy of oxidation

R

Gas constant

T

Surface temperature

t0

Vibration time of adsorbed molecules

u

Sliding speed

VCV

Volume of a control volume

Vp

Volume of a wear particle

X

Diameter of adsorbed molecules

α

Fractional film defect

x, ∆yz

Length of each axis of the control volume

E

Difference of adsorption heat of additive and base oil

S

Total entropy change associated with adsorption

θ

Fractional surface coverage by additive

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Notes

Acknowledgments

This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP) through GCRC-SOP (No. 2011-0030013).

References

  1. [1]
    W. B. Hardy and I. Doubleday, Boundary lubrication—The paraffin series, Proc. R. Soc. Lond. A, 100 (707) (1922) 550–574.CrossRefGoogle Scholar
  2. [2]
    I. Langmuir, The constitution and fundamental properties of solids and liquids. Part I. Solids, J. Am. Chem. Soc., 38 (11) (1916) 2221–2295.CrossRefGoogle Scholar
  3. [3]
    F. P. Bowden, J. N. Gregory and D. Tabor, Lubrication of metal surfaces by fatty acids, Nature, 156, (1945) 97–101.CrossRefGoogle Scholar
  4. [4]
    E. P. Kingsbury, Some aspects of the thermal desorption of a boundary lubricant, J. Appl. Phys., 29 (6) (1958) 888–891.CrossRefGoogle Scholar
  5. [5]
    C. N. Rowe, Some aspects of the heat of adsorption in the function of a boundary lubricant, ASLE Trans., 9 (1) (1966) 101–111.MathSciNetCrossRefGoogle Scholar
  6. [6]
    C. N. Rowe, Role of additive adsorption in the mitigation of wear, ASLE Trans., 13 (3) (1970) 179–188.CrossRefGoogle Scholar
  7. [7]
    T. A. Stolarski, Evaluation of the heat of adsorption of a boundary lubricant, ASLE Trans., 30 (4) (1986) 472–478.CrossRefGoogle Scholar
  8. [8]
    T. A. Stolarski, A system for wear prediction in lubricated sliding contacts, Lubr. Sci., 8 (4) (1996) 315–351.CrossRefGoogle Scholar
  9. [9]
    K. L. Johnson, J. A. Greenwood and S. Y. Poon, A simple theory of asperity contact in elastohydro-dynamic lubrication, Wear, 19 (1) (1972) 91–108.CrossRefGoogle Scholar
  10. [10]
    M. Masuko, S. Aoki and A. Suzuki, Influence of lubricant additive and surface texture on the sliding friction characteristics of steel under varying speed ranging from ultra-low to moderate, Tribol. T., 48 (3) (2005) 289–298.CrossRefGoogle Scholar
  11. [11]
    T. Norihisa, F. Itoigawa and T. Nakamura, Study on velocity- dependent property of friction in boundary lubrication under low contacting pressure condition (Part 1): Relationship between additives and velocity-dependent property of friction, J. Jpn. Soc. Tribologis., 53 (10) (2008) 682–688 (in Japanese).Google Scholar
  12. [12]
    T. Norihisa, F. Itoigawa, T. Nakamura and T. Ogawa, Study on velocity-dependent property of friction in boundary lubrication under low contacting pressure condition (Part 2): Consideration into mechanism of velocity-dependent property of friction lubricated with oil containing alkyl acid phosphate, J. Jpn. Soc. Tribologis., 53 (10) (2008) 689–696 (in Japanese).Google Scholar
  13. [13]
    H. Okabe, M. Masuko and K. Sakurai, Dynamic behavior of surface-adsorbed molecules under boundary lubrication, ASLE Trans., 24 (4) (1981) 467–473.CrossRefGoogle Scholar
  14. [14]
    M. Masuko, K. Moriki and H. Okabe, A study on boundary friction (2nd report), J. Jpn. Soc. Lubr. Eng., 30 (6) (1985) 422–429.Google Scholar
  15. [15]
    N. Saravanakumar, M. L. Jothi Saravanan, K. E. Barathkumar, K. Gokula Kannan and R. Karthikeyan, Development and testing of nano particulate lubricant for worm gear application, J. Mech. Sci. Technol., 33 (4) (2019) 1785–1791.CrossRefGoogle Scholar
  16. [16]
    P. R. Nayak, Some aspects of surface roughness measurement, Wear, 26 (2) (1973) 165–174.CrossRefGoogle Scholar
  17. [17]
    J. A. Greenwood and J. B. P. Williamson, Contact of nominally flat surfaces, Proc. R. Soc. Lond. A, 295 (1442) (1966).Google Scholar
  18. [18]
    S. S. Kurtz, The Chemistry of Petroleum Hydrocarbons, Vol. 11, Reinhold, New York and London (1954).Google Scholar
  19. [19]
    A. Beerbower, A critical survey of mathematical models for boundary lubrication, ASLE Trans., 14 (2) (1971) 90–104.CrossRefGoogle Scholar
  20. [20]
    G. Stachowiak and A. W. Batchelor, Engineering Tribology, Butterworth-Heinemann (2013)Google Scholar

Copyright information

© KSME & Springer 2019

Authors and Affiliations

  • Bora Lee
    • 1
  • Yonghun Yu
    • 2
  • Dae-Seung Cho
    • 2
  • Yongjoo Cho
    • 1
    Email author
  1. 1.School of Mechanical EngineeringPusan National UniversityBusanKorea
  2. 2.Dept. of Naval Architecture & Ocean EngineeringPusan National UniversityBusanKorea

Personalised recommendations