Investigation of calcium phosphate (CaP) tribofilms from commercial automatic transmission fluids (ATFs) and their correlation with antishudder performance


The friction properties of wet clutches are highly dependent on the surface tribofilms formed by automatic transmission fluids (ATFs). Here, four commercial ATFs were evaluated with a disc-on-disc tribometer to study tribofilm formation on steel surfaces and the effects of tribofilms on the friction properties. The chemical composition, stoichiometry, structure, and thickness of the tribofilms were investigated by scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDX), secondary ion mass spectrometry (SIMS), and X-ray photoelectron spectroscopy (XPS). Calcium phosphate (CaP) tribofilms form on the friction surface with all ATFs, which contributes to their antishudder characteristics. The thickness and surface coverage of CaP tribofilms are positively correlated with their antishudder properties.


  1. [1]

    Ingram M, Spikes H, Noles J, Watts R. Contact properties of a wet clutch friction material. Tribol Int43(4): 815–821 (2010)

    Article  Google Scholar 

  2. [2]

    Farfán-Cabrera L I, Gallardo-Hernández E A, Vite-Torres M, Laguna-Camacho J R. Frictional behavior of a wet clutch using blends of automatic transmission fluid (ATF) and Biolubricant (Jatropha Oil) in a pin-on-disk tester. Tribol Trans58(5): 941–946 (2015)

    Article  Google Scholar 

  3. [3]

    Xu R G, Leng Y S. Squeezing and stick-slip friction behaviors of lubricants in boundary lubrication. Proc Natl Acad Sci USA115(26): 6560–6565 (2018)

    Article  Google Scholar 

  4. [4]

    Zhang J, Meng Y G. Boundary lubrication by adsorption film. Friction3(2): 115–147 (2015)

    Article  Google Scholar 

  5. [5]

    Parsaeian P, Ghanbarzadeh A, Van Eijk M C P, Nedelcu I, Neville A, Morina A. A new insight into the interfacial mechanisms of the tribofilm formed by zinc dialkyl dithiophosphate. Appl Surf Sci403: 472–486 (2017)

    Article  Google Scholar 

  6. [6]

    Rydel J J, Pagkalis K, Kadiric A, Rivera-Díaz-Del-Castillo P E J. The correlation between ZDDP tribofilm morphology and the microstructure of steel. Tribol Int113: 13–25 (2017)

    Article  Google Scholar 

  7. [7]

    Masuko M, Shibatsuji M, Yokomizo M, Aoki S, Suzuki A. On the effort to discriminate the principal function of tribofilm on friction under the boundary lubrication condition. Tribol Int44(6): 702–710 (2011)

    Article  Google Scholar 

  8. [8]

    Zhao H Y, Neville A, Morina A, Vickerman R, Durham J. Improved anti-shudder performance of ATFs—influence of a new friction modifier and surface chemistry. Tribol Int46(1): 62–72 (2012)

    Article  Google Scholar 

  9. [9]

    Wan Y, Kasrai M, Bancroft G M, Zhang J. Characterization of tribofilms derived from zinc dialkyldithiophosphate and salicylate detergents by X-ray absorbance near edge structure spectroscopy. Tribol Int43(1–2): 283–288 (2010)

    Article  Google Scholar 

  10. [10]

    Burkinshaw M, Neville A, Morina A, Sutton M. The lubrication of both aluminium–silicon and model silicon surfaces with calcium sulphonate and an organic antiwear additive. Tribol Int67: 211–216 (2013)

    Article  Google Scholar 

  11. [11]

    Konicek A R, Jacobs P W, Webster M N, Schilowitz A M. Role of tribofilms in wear protection. Tribol Int94: 14–19 (2016)

    Article  Google Scholar 

  12. [12]

    Stratmann A, Jacobs G, Hsu C J, Gachot C, Burghardt G. Antiwear tribofilm growth in rolling bearings under boundary lubrication conditions. Tribol Int113: 43–49 (2017)

    Article  Google Scholar 

  13. [13]

    Nicholls M A, Do T, Norton P R, Kasrai M, Bancroft G M. Review of the lubrication of metallic surfaces by zinc dialkyldithiophosphates. Tribol Int38: 15–39 (2005)

    Article  Google Scholar 

  14. [14]

    Gosvami N N, Bares J A, Mangolini F, Konicek A R, Yablon D G, Carpick R W. Mechanisms of antiwear tribofilm growth revealed in situ by single-asperity sliding contacts. Science348(6230): 102–106 (2015)

    Article  Google Scholar 

  15. [15]

    Shimizu Y, Spikes H A. The tribofilm formation of ZDDP under reciprocating pure sliding conditions. Tribol Lett64(3): 46 (2016)

    Article  Google Scholar 

  16. [16]

    Tohyama M, Ohmori T, Ueda F. Anti-shudder mechanism of ATF additives at slip-controlled lockup clutch. SAE Technical Paper: 1999-01-3616 (1999)

    Google Scholar 

  17. [17]

    Derevjanik T S. Detergent and friction modifier effects on metal/metal and clutch material/metal frictional performance. SAE Technical Paper: 2001-01-1993 (2001)

    Google Scholar 

  18. [18]

    Fatima N, Marklund P, Larsson R. Study on the wet clutch friction interfaces for humid lubrication condition. In Proceedings of the Third International Tribology Symposium of IFToMM, Luleå, Sweden, 2013.

    Google Scholar 

  19. [19]

    Li S H, Di Z C, Zhao Z Y, Liu Y, Xu J J, Cui H T, Huang D S, Liu Z G, Li Y. Effection of calcium phosphate tribofilm on anti-shudder performance in ATFs. Tribol Int120: 1–8 (2018)

    Article  Google Scholar 

  20. [20]

    Li S H, Di Z C, Cheng L, Liu Z G, Piao J C, Huang D S, Zhao Z Y, Cui H T, Li Y. Surface chemical characterization of steel clutch plate in ATF. Tribol Int102: 319–325 (2016)

    Article  Google Scholar 

  21. [21]

    Zhao H Y, Morina A, Neville A, Vickerman R. Anti-shudder properties of ATFs—investigation into tribofilm composition on clutch friction material and steel surfaces and the link to frictional performance. Tribol Trans55(6): 782–797 (2012)

    Article  Google Scholar 

  22. [22]

    Tiption C D, Huston M E, Wetsel W R. Fundamental studies on ATF friction, Part II. SAE Technical Paper: 982670 (1998)

    Google Scholar 

  23. [23]

    Qu J, Meyer III H M, Cai Z B, Ma C, Luo H M. Characterization of ZDDP and ionic liquid tribofilms on non-metallic coatings providing insights of tribofilm formation mechanisms. Wear332–333: 1273–1285 (2015)

    Article  Google Scholar 

  24. [24]

    Smentkowski V S, Keenan M R, Arlinghaus H. Using ToF-SIMS to study industrial surface phenomena. Surf Sci652: 39–45 (2016)

    Article  Google Scholar 

  25. [25]

    Japanese Automobile Standard JASO M349-2001 Road vehicles-Test method for anti-shudder performance of automatic transmission fluids.

  26. [26]

    Boyd A R, O’Kane C, Meenan B J. Control of calcium phosphate thin film stoichiometry using multi-target sputter deposition. Surf Coat Technol233: 131–139 (2013)

    Article  Google Scholar 

  27. [27]

    Nguyen T P, Dupraz A. Spectroscopic studies of a multiphasic polymer-ceramic mixture material. J Biomater Sci Polym Ed8(2): 141–149 (1997)

    Article  Google Scholar 

  28. [28]

    Etsion I. Modeling of surface texturing in hydrodynamic lubrication. Friction1(3): 195–209 (2013)

    Article  Google Scholar 

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The authors are grateful to the Petrochina Company Limited for financial support.

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Correspondence to Zechao Di.

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Zechao DI. She received her Ph.D. degree in mechanical engineering in 2006 from Tsinghua University, Beijng, China. She joined Lubricating Oil Research & Development Institute of PetroChina from 2007. Her research areas cover the friction and lubrication of automotive automatic transmission fluid.

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Di, Z., Xu, J., Liu, Y. et al. Investigation of calcium phosphate (CaP) tribofilms from commercial automatic transmission fluids (ATFs) and their correlation with antishudder performance. Friction 8, 882–892 (2020).

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  • tribofilm
  • commercial ATF
  • antishudder
  • hydroxyapatite