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Tribology Letters

, Volume 17, Issue 4, pp 811–822 | Cite as

The Correlation of Microchemical Properties to Antiwear (AW) Performance in Ashless Thiophosphate Oil Additives

  • M.N. Najman
  • M. Kasrai
  • G. M. Bancroft
  • B. H. Frazer
  • G. De Stasio
Article

Abstract

X-ray absorption near-edge structure (XANES) spectroscopy at macro-scale (mm2) and X-ray photoelectron emissions microscopy (X-PEEM) at micro-scale (μm2) have been used to investigate the chemistry and spatial distributions of chemical species in tribochemical films generated from ashless thiophosphate oil additives on steel. Two different ashless thiophosphate additives were used: a triaryl monothiophosphate (MTP) and a dialkyldithiophosphate (DTP). Atomic force microscopy (AFM) and secondary electron microscopy (SEM) were also used to investigate the thickness and the topography of the tribofilms. Macro-scale XANES analysis showed that both ashless thiophosphates reacted with the steel surface to produce short to medium chain polyphosphates as the main constituent and sulfur species as minor component. From the PEEM experiment, it was found that the DTP tribofilm was microchemically heterogeneous, with areas of varying degrees of polyphosphate chain length. Conversely, MTP formed a tribofilm microchemically homogeneous, with areas comprised of only short chain polyphosphates. From, the different areas of polyphosphate chain length within the DTP tribofilm, colour-coded polyphosphate distribution map was generated. AFM, X-PEEM and SEM revealed that the DTP film was thicker and was composed of AW pads that were wider in area than MTP. This resulted in a smaller wear scar width (WSW) value for DTP. This is the first time that all these analytical techniques have been combined to better understand the nature of the tribofilms from ashless additives. We have concluded that an ideal AW film is comprised of a thick film with pad-like structures that are wider in area and microchemically heterogeneous, with areas of varying polyphosphate chain length.

thiophosphates XANES spectroscopy X-PEEM microscopy anti-wear AFM wear protection 

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References

  1. [1]
    R. Sarin, V. Martin, D. K. Tuli, M. M. Rai and A. K. Bhatnagar, Lub. Eng. 53 (1997) 21.Google Scholar
  2. [2]
    W. A. Gehrmann, SAE Paper No. 921736 (1992)Google Scholar
  3. [3]
    R. Sarin, A. K. Gupta, D. K. Tuli, A. S. Verma, M. M. Rai and A. K. Bhatnagar, Trib. Int. 26 (1993) 389.Google Scholar
  4. [4]
    S. Anders, T. Stammler, W. Fong, D. B. Bogy, C. S. Bhatia and J. Sto¨ hr, J. Vac. Sci. Technol. A. 17 (1999) 2731.Google Scholar
  5. [5]
    Z. Yin, M. Kasrai, M. Fuller, G. M. Bancroft, K. Fyfe and K. H. Tan, Wear 202 (1997) 172.Google Scholar
  6. [6]
    M. Kasrai, J. N. Cutler, K. Gore, G. Canning, G. M. Bancroft and K. H. Tan, Tribol. Transact. 49 (1998) 69.Google Scholar
  7. [7]
    M. N. Najman, M. Kasrai, G. M. Bancroft and A. Miller, Trib. Lett. 13 (2002) 209.Google Scholar
  8. [8]
    M. N. Najman, M. Kasrai and G. M. Bancroft, Trib. Lett. 14 (2003) 225.Google Scholar
  9. [9]
    M. Kasrai, W. Lennard, R. W. Brunner, G. M. Bancroft, J. A. Bardwell and K. H. Tan, Appl. Surf. Sci. 99 (1996) 303.Google Scholar
  10. [10]
    M. N. Najman, M. Kasrai and G. M. Baner of wear (in press).Google Scholar
  11. [11]
    G. W. Canning, M. L. Suominen-Fuller, G. M. Bancroft, M. Kasrai, J. N. Cutler, G. De Stasio and B. Gilbert, Trib. Lett. 6 (1999) 159.Google Scholar
  12. [12]
    T. Warwick et al., Synchrotron Radiat. News 11 (1998) 5.Google Scholar
  13. [13]
    J. Sto¨ hr and S. Anders, IBM J. Res. Develop. 44 (2000) 535.Google Scholar
  14. [14]
    M. A. Nicholls, P. R. Norton, G. M. Bancroft, M. Kasrai, T. Do, B. H. Frazer, G. De Stasio, Trib. Lett. 17 (2004) 205.Google Scholar
  15. [15]
    G. M. Bancroft, Can. Chem. News 44 (1992) 15.Google Scholar
  16. [16]
    M. Kasrai, Z. Yin, G. M. Bancroft and K. H. Tan, J. Vac. Sci. Technol. A 11 (1993) 2694.Google Scholar
  17. [17]
    M. Fuller, L. R. Fernandez, G. R. Massoumi, W. N. Lennard, M. Kasrai and G. M. Bancroft, Trib. Lett. 8 (2000) 187.Google Scholar
  18. [18]
    G. De Stasio et al., Rev. Sci. Inst. 69 (1998) 3106.Google Scholar
  19. [19]
    J. Sto¨ hr, NEXAFS Spectroscopy (Springer, New York, 1992).Google Scholar
  20. [20]
    C. Jacobsen, S. Wirick, G. Flynn and C. Zimba, J. Micros. 197 (2000) 173.Google Scholar
  21. [21]
    A. P. Hitchcock, P. Hitchcock, C. Jacobson, C. Zimba, L. B. E. Rotenberg, J. Denlinger and R. Kneedler, aXis2000 – program available from http://unicorn. mcmaster. ca/aXis2000. html (1997).Google Scholar
  22. [22]
    D. G. L. Sutherland, M. Kasrai, G. M. Bancroft, Z. F. Liu and K. H. Tan, Phys. Rev. B 48 (1993) 14989.Google Scholar
  23. [23]
    Z. Yin, M. Kasrai, G. M. Bancroft, K. H. Tan and X. Feng, Phys. Rev. B. 51 (1995) 742.Google Scholar
  24. [24]
    J. M. Martin, C. Grossiord, T. Le Mogne, S. Bec and A. Tonck, Trib. Int. 34 (2001) 523.Google Scholar
  25. [25]
    ICP analyses were performed at the Sarnia Research Center at Imperial Oil CanadaGoogle Scholar
  26. [26]
    J. F. Graham, C. McCague and P. R. Norton, Trib. Lett. 6 (1999) 149.Google Scholar
  27. [27]
    I. N. Koprinarov, A. P. Hitchcock, C. T. McCrory and R. F. Childs, J. Phys. Chem. B. 106 (2002) 5358.Google Scholar
  28. [28]
    X. Zhang, R. Balhorn, J. Mazrimas and J. Kirz, J. Struct. Biol. 116 (1996) 335.Google Scholar
  29. [29]
    M. N. Najman, M. Kasrai and G. M. Baner of wear (in press).Google Scholar
  30. [30]
    F. G. Rounds, ASLE Trans. 30 (1987) 479.Google Scholar
  31. [31]
    E. S. Yamaguchi, P. R. Ryason, E. Q. Labrador and T. P. Hansen, Trib. Trans. 39 (1996) 220.Google Scholar

Copyright information

© Springer Science+Business Media, Inc. 2004

Authors and Affiliations

  • M.N. Najman
    • 1
  • M. Kasrai
    • 1
  • G. M. Bancroft
    • 1
  • B. H. Frazer
    • 2
  • G. De Stasio
    • 2
  1. 1.Department of ChemistryUniversity of Western OntarioLondonCanada
  2. 2.Department of PhysicsUniversity of Wisconsin-MadisonMadisonUSA

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