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Tribology Letters

, Volume 6, Issue 3–4, pp 181–189 | Cite as

A dual‐analysis approach in tribochemistry: application to ZDDP/calcium borate additive interactions

  • K. Varlot
  • J.M. Martin
  • C. Grossiord
  • R. Vargiolu
  • B. Vacher
  • K. Inoue
Article

Abstract

Tribochemical interactions between zinc dithiophosphate (ZDDP) and micellar calcium borate (CB) under boundary lubrication were investigated by coupling, in the same location of the wear track, both analytical TEM analysis of collected wear fragments from the tribofilm and XPS surface analysis of the tribofilm directly underneath. This is the so‐called dual‐analysis approach, which improves the interpretation of tribochemical reactions. The elemental composition inside the wear scars was analysed by micro‐spot XPS. By depth profiling, the film thickness could also be determined. In particular, the efficiency of the additive combination could be proven by quantification of iron oxide. The nature of wear particles was investigated in the TEM by using EELS and EDX simultaneously, with the result that phosphorus, boron and sulphur contributions have been carefully distinguished. The technique is very powerful for determining the composition of the material through quantification of both EELS and EDX spectra on the same specimen. The main result, when ZDDP and CB additives are used together, is the formation of a calcium and zinc borophosphate glass tribofilm. The overall data confirm the general friction‐induced glass model as being a unifying concept that explains the mechanisms of antiwear additives under boundary lubrication. Moreover, the analytical results strongly suggest the role of viscous flow of the magma state glass tribofilm above its glass transition temperature to be a main contribution to the antiwear mechanism under mild wear conditions.

antiwear additive ZDDP tribochemistry borophosphate glass 

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References

  1. [1]
    D. Faure et al., in: Proceedings JTC Int. Conf., Nagoya, Japan, (1990) p. 1043.Google Scholar
  2. [2]
    J.L. Mansot, M. Hallouis and J.M. Martin, Colloids and Surfaces A 75(1993) 25.CrossRefGoogle Scholar
  3. [3]
    K. Inoue, Lub. Eng. 49(1993) 263.Google Scholar
  4. [4]
    J.M. Martin, J.L. Lavergne, B. Vacher and K. Inoue, Microsc. Microanal. Microstruct. 6(1995) 53.CrossRefGoogle Scholar
  5. [5]
    V. Normand, J.M. Martin and K. Inoue, Tribol. Lett.Google Scholar
  6. [6]
    R.K. Brow, J. Non-Cryst. Solids194(1996) 267.CrossRefGoogle Scholar
  7. [7]
    R. Gresch, W. Müller-Warmuthm and H. Dutz, J. Non-Cryst. Solids 34(1979) 127.CrossRefGoogle Scholar
  8. [8]
    W. Vogel, Glass Chemistry(Springer, Berlin, 1985) p. 159.Google Scholar
  9. [9]
    R.J. Kirkpatrick and R.K. Brow, Solid State Nuclear Magn. Res.5 (1995) 9.CrossRefGoogle Scholar
  10. [10]
    C.C. Ahn and O.L. Krivanek, EELS Atlas, Gatan Inc., 1983.Google Scholar
  11. [11]
    N.H. Ray, Inorganic Polymers (Academic Press, London, 1978) pp. 79–90.Google Scholar
  12. [12]
    O.L. Warren, J.F. Graham, P.R. Norton, J.E. Houston and T.A. Michalske, Tribol. Lett.4(1998) 189.CrossRefGoogle Scholar

Copyright information

© Kluwer Academic Publishers 1999

Authors and Affiliations

  • K. Varlot
    • 1
  • J.M. Martin
    • 1
  • C. Grossiord
    • 1
  • R. Vargiolu
    • 1
  • B. Vacher
    • 1
  • K. Inoue
    • 2
  1. 1.Laboratoire de Tribologie et Dynamique des SystèmesEcole Centrale de LyonEcullyFrance
  2. 2.Central Technical Research LaboratoryNippon Oil Co., Ltd.Yokohama 231Japan

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