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The Influence of DLC Coating on EHL Friction Coefficient

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Abstract

High hardness, high elastic modulus, low friction characteristics, high wear and corrosion resistance, chemical inertness, and thermal stability are factors that make diamond-like carbon (DLC) coatings the subject of many studies. For the same reasons they also seem suitable for use in, amongst others, machine components and cutting tools. While most studies in the literature focus on the influence of coatings on wear and friction in boundary lubrication and pure sliding contacts, few studies can be found concerning rolling and sliding elastohydrodynamic lubrication (EHL) friction, especially in the mixed and full film regime. In this article tests are carried out in a Wedeven Associates Machine tribotester where an uncoated ball and disc pair is compared to the case of coated ball against uncoated disc, coated disc against uncoated ball, and coated disc against coated ball. The tests are conducted at two different temperatures and over a broad range of slide-to-roll ratios and entrainment speeds. The results are presented as friction maps as introduced in previous work (Björling et al. in J Eng Tribol 225(7):671, 2011). Furthermore a numerical simulation model is developed to investigate if there is a possibility that the hard, thin DLC coating is affecting the friction coefficient in an EHL contact due to thermal effects caused by the different thermal properties of the coating compared to the substrate. The experimental results show a reduction in friction coefficient in the full film regime when DLC-coated surfaces are used. The biggest reduction is found when both surfaces are coated, followed by the case when either ball or disc is coated. The thermal simulation model shows a substantial increase of the lubricant film temperature compared to uncoated surfaces when both surfaces are coated with DLC. The reduction in friction coefficient when coating either only the ball or the disc are almost the same, lower than when coating both the surfaces but still higher than the uncoated case. The findings above indicate that it is reasonable to conclude that thermal effects are a likely cause for the decrease in coefficient of friction when operating under full film conditions, and in the mixed lubrication regime when DLC-coated surfaces are used.

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References

  1. Ronkainen, H., Varjus, D., Holmberg, K.: Friction and wear properties in dry, water- and oil-lubricated DLC against alumina and DLC against steel contacts. Wear 222(2), 120 (1998)

    Article  CAS  Google Scholar 

  2. Zhou, Z., Li, K., Bello, I., Lee, C., Lee, S.: Study of tribological performance of ECR–CVD diamond-like carbon coatings on steel substrates. Part 2. The analysis of wear mechanism. Wear 258(10), 1589 (2005)

    Article  CAS  Google Scholar 

  3. Podgornik, B., Jacobson, S., Hogmark, S.: DLC coating of boundary lubricated components—advantages of coating one of the contact surfaces rather than both or none. Tribol. Int. 36(11), 843 (2003)

    Article  CAS  Google Scholar 

  4. Podgornik, B., Jacobson, S., Hogmark, S.: Influence of EP additive concentration on the tribological behaviour of DLC-coated steel surfaces. Surf. Coat. Technol. 191(2–3), 357 (2005)

    Article  CAS  Google Scholar 

  5. Podgornik, B., Hren, D., Vižintin, J.: Combination of DLC coatings and EP additives for improved tribological behaviour of boundary lubricated surfaces. Wear 261(1), 32 (2006)

    Article  CAS  Google Scholar 

  6. Mistry, K., Morina, A., Neville, A.: Tribo-chemistry of lubricated DLC coatings for engineering components under extreme-pressure contact conditions. Tribol. Lubr. Technol. 66(5), 16 (2010)

    Google Scholar 

  7. de Barros’Bochet, M., Martin, J., Le-Mogne, T., Vacher, B.: Lubrication of carbon coatings with MoS2 single sheet formed by MoDTC and ZDDP lubricants. Lubr. Sci. 18(3), 141 (2006)

    Article  Google Scholar 

  8. de Barros’Bochet, M., Martin, J., Le-Mogne, T., Vacher, B.: Boundary lubrication mechanisms of carbon coatings by MoDTC and ZDDP additives. Tribol. Int. 38(3), 257 (2005)

    Article  Google Scholar 

  9. Miyake, S., Saito, T., Yasuda, Y., Okamato, Y., Kano, M.: Improvement of boundary lubrication properties of diamond-like carbon (DLC) films due to metal addition. Tribol. Int. 37(9), 751 (2004)

    Article  CAS  Google Scholar 

  10. Haque, T., Morina, A., Neville, A., Kapadia, R., Arrowsmith, S.: Effect of oil additives on the durability of hydrogenated DLC coating under boundary lubrication conditions. Wear 266(1–2), 147 (2009)

    Article  CAS  Google Scholar 

  11. Kalin, M., Roman, E., Ožbolt, L., Vižintin, J.: Metal-doped (Ti, WC) diamond-like-carbon coatings: reactions with extreme-pressure oil additives under tribological and static conditions. Thin Solid Films 518(15), 4336 (2010)

    Article  CAS  Google Scholar 

  12. Topolovec-Miklozic, K., Lockwood, F., Spikes, H.: Behaviour of boundary lubricating additives on DLC coatings. Wear 265(11–12), 1893 (2008)

    Article  CAS  Google Scholar 

  13. Yoshida, K., Horiuchi, T., Kano, M., Kumagai, M.: Effect of a tribochemical reacted film on friction and wear properties of DLC coatings. Plasma Process. Polym. 6(1), S96 (2009)

    Article  CAS  Google Scholar 

  14. Renodeau, H., Papke, B., Pozebanchukz, M., Parthasarathy, P.: Tribological properties of diamond-like carbon coatings in lubricated automotive applications. Proc. Inst. Mech. Eng. Part J J. Eng. Tribol. 223(3), 405 (2009)

    Article  Google Scholar 

  15. Kalin, M., Vižintin, J.: Differences in the tribological mechanisms when using non-doped, metal-doped (Ti, WC), and non-metal-doped (Si) diamond-like carbon against steel under boundary lubrication, with and without oil additives. Thin Solid Films 515(4), 2734 (2006)

    Article  CAS  Google Scholar 

  16. Bobzin, K., Bagcivan, N., Goebbels, N., Yilmaz, K., Hoehn, B.R., Michaelis, K., Hochmann, M.: Lubricated PVD CrAlN and WC/C coatings for automotive applications. Surf. Coat. Technol. 204(6-7), 1097 (2009)

    Article  CAS  Google Scholar 

  17. Xu, H.: Development of a generalized mechanical efficiency prediction methodology for gear pairs. PhD thesis, Graduate School of The Ohio State University (2005)

  18. Evans, R., Cogdell, J., Richter, G.: Traction of lubricated rolling contacts between thin-film coatings and steel. Tribol. Trans. 52(1), 106 (2009)

    Article  CAS  Google Scholar 

  19. Choo, J., Glovnea, R., Forrest, A., Spikes, H.: A low friction bearing based on liquid slip at the wall. J. Tribol. 129(3), 611 (2007)

    Article  Google Scholar 

  20. Björling, M., Larsson, R., Marklund, P., Kassfeldt, E.: Elastohydrodynamic lubrication friction mapping—the influence of lubricant, roughness, speed, and slide-to-roll ratio. Proc. Inst. Mech. Eng. Part J J. Eng. Tribol. 225(7), 671 (2011)

    Article  Google Scholar 

  21. Larsson, R., Larsson, P., Eriksson, E., Sjoberg, M., Hoglund, E.: Lubricant properties for input to hydrodynamic and elastohydrodynamic lubrication analyses. Proc. Inst. Mech. Eng. Part J J. Eng. Tribol. 214(1), 17 (2000)

    Article  Google Scholar 

  22. Habchi, W., Eyheramendy, D., Bair, S., Vergne, P., Morales-Espejel, G.: Thermal elastohydrodynamic lubrication of point contacts using a newtonian/generalized newtonian lubricant. Tribol. lett. 30(1), 41 (2008)

    Article  CAS  Google Scholar 

  23. Kim, J., Yang, H.S., Jun, Y., Kim, K.: Interfacial effect on thermal conductivity of diamond-like carbon films. J. Mech. Sci. Technol. 24(7), 1511 (2010)

    Article  Google Scholar 

  24. Wojciechowski, K., Zybala, R., Mania, R.: Application of DLC layers in 3-omega thermal conductivity method. J. Achiev. Mater. Manuf. Eng. 37(2), 512 (2009)

    Google Scholar 

  25. Hakovirta, M., Vuorinen, J., He, X., Nastasi, M., Schwarz, R.: Heat capacity of hydrogenated diamond-like carbon films. Appl. Phys. Lett. 77(15), 2340 (2000)

    Article  CAS  Google Scholar 

  26. Oka, Y., Kirinuki, M., Suzuki, T., Yatsuzuka, M., Yatsui, K.: Effect of ion beam implantation on density of DLC prepared by plasma-based ion implantation and deposition. Nucl. Instrum. Methods Phys. Res. Sect. B Beam Interact. Mater. At. 242(1–2), 335 (2006)

    Article  CAS  Google Scholar 

  27. Hamrock, B., Schmid, S., Jacobson, B.: Fundamentals of Fluid Film Lubrication, 2nd edn. Marcel Dekker Inc., New York (2004)

    Book  Google Scholar 

  28. Hsu, C.H., Lee, R.T.: An efficient algorithm for thermal elastohydrodynamic lubrication under rolling/sliding line contacts. J. Tribol. 116(4), 762 (1994)

    Article  Google Scholar 

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Acknowledgments

The authors gratefully acknowledge industrial partners Volvo Construction Equipment, Scania and Vicura AB for support, Ion bond for providing the coatings, Statoil lubricants for providing the test lubricant, and Swedish Foundation for Strategic Research (ProViking) for financial support.

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Authors and Affiliations

  1. Division of Machine Elements, Department of Engineering Science and Mathematics, Luleå University of Technology, 97187, Luleå, Sweden

    M. Björling, P. Isaksson, P. Marklund & R. Larsson

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  1. M. Björling
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  2. P. Isaksson
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  3. P. Marklund
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  4. R. Larsson
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Correspondence to M. Björling.

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Björling, M., Isaksson, P., Marklund, P. et al. The Influence of DLC Coating on EHL Friction Coefficient. Tribol Lett 47, 285–294 (2012). https://doi.org/10.1007/s11249-012-9987-7

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  • DOI: https://doi.org/10.1007/s11249-012-9987-7

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