Abstract
Lubrication failure of polyalphaolefin (PAO) oil film at high slide/roll ratios of more than 1.9 has been experimentally investigated based on a ball-on-disc configuration. The central film thickness and the oil pool shape in the contact were determined by optical interferometry and fluorescence microscopy, respectively, and the traction coefficient and surface profiles of the tribopairs were measured using a tension-compression sensor and light surface profilometer, respectively. The results demonstrate that the central film in the contact was in the elastohydrodynamic lubrication regime at the initial stage under high slide/roll ratios. Variation in the traction coefficient and the presence of wear scars on the disc surface shows that the sliding speed played an important role in lubrication failure. We propose that a thermal effect explains the obtained results at high slide/roll ratios. The fluorescence technique combined with optical interferometry was also used to gain more understanding of lubrication properties under mixed slide/roll conditions.
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Lord, J., Larsson, R.: Effects of slide-roll ratio and lubricant properties on elastohydrodynamic lubrication film thickness and traction. Proc. Inst. Mech. Eng. J. Eng. Tribol. 215, 301–308 (2001)
Dalmaz, G., Chaomleffel, J.P.: Elastohydrodynamic lubrication of point contacts for various lubricants. Tribol. Ser. 11, 207–218 (1987)
Fan, J., Muller, M., Stohr, T., Spikes, H.A.: Reduction of friction by functionalised viscosity index improvers. Tribol. Lett. 28, 287–298 (2007)
Smeeth, M., Spikes, H.A.: The influence of slide/roll ratio on the film thickness of an EHD contact operating within the mixed lubrication regime. Tribol. Ser. 31, 695–703 (1996)
Ciulli, E., Stadler, K., Draexl, T.: The influence of the slide-to-roll ratio on the friction coefficient and film thickness of EHD point contacts under steady state and transient conditions. Tribol. Int. 42, 526–534 (2009)
Jubaulta, I., Molimardb, J., Lubrechtc, A.A., Mansot, J.L., Vergne, P.: In situ pressure and film thickness measurements in rolling sliding lubricated point contacts. Tribol. Lett. 15, 421–429 (2003)
Hili, J., Olver, A.V., Edwards, S., Jacobs, L.: Experimental investigation of elastohydrodynamic film thickness behavior at high speeds. Tribol. Trans. 53, 658–666 (2010)
Guo, F., Wong, P.L., Geng, M., Kaneta, M.: Occurrence of wall slip in elastohydrodynamic lubrication contacts. Tribol. Lett. 34, 103–111 (2009)
Smart, A.E., Ford, R.A.J.: Measurement of thin liquid films by a fluorescence technique. Wear 29, 41–47 (1974)
Myant, C., Reddyhoff, T., Spikes, H.A.: Laser-induced fluorescence for film thickness mapping in pure sliding lubricated, compliant, contacts. Tribol. Int. 43, 1960–1969 (2010)
Pit, R., Hervet, H., Leger, L.: Friction and slip of a simple liquid at a solid surface. Tribol. Lett. 7, 147–152 (1999)
Reddyhoff, T., Choo, J.H., Spikes, H.A., Glovnea, R.P.: Lubricant flow in an elastohydrodynamic contact using fluorescence. Tribol. Lett. 38, 207–215 (2010)
Ma, L.R., Zhang, C.H.: Discussion on the technique of relative optical interference intensity for the measurement of lubricant film thickness. Tribol. Lett. 36, 239–245 (2009)
Luo, J.B., Wen, S.Z., Huang, P.: Thin film lubrication. Part I. Study on the transition between EHL and thin film lubrication using a relative optical interference intensity technique. Wear 194, 107–115 (1996)
Xie, G.X., Luo, J.B., Liu, S.H., Guo, D., Zhang, C.H.: Nanoconfined liquid aliphatic compounds under external electric fields: roles of headgroup and alkyl chain length. Soft Matter 7, 4453–4460 (2011)
Xie, G.X., Luo, J.B., Liu, S.H., Guo, D., Zhang, C.H.: Electric-fields-enhanced destabilization of oil-in-water emulsions flowing through a confined wedgelike gap. J. Appl. Phys. 108, 064314-064314-9 (2010)
Xiao, H.P., Guo, D., Liu, S.H., Lu, X.C., Luo, J.B.: Experimental investigation of lubrication properties at high contact pressure. Tribol. Lett. 40, 85–97 (2010)
Hamrock, B.J., Dowson, D.: Isothermal elastohydrodynamic lubrication of point contacts, part III, fully flooded results. J. Lubr. Technol. 99, 264–276 (1977)
Zhou, S.Q., Rui, N., Denis, F.: Effects of shear rate and temperature on viscosity of alumina polyalphaolefins nanofluids. J Appl. Phys 107 054317, 1–6 (2010)
Chevalier, F., Lubrecht, A.A., Cann, P.M.E., Colin, F., Dalmaz, G.: Starvation phenomena in EHL point contacts: influence of inlet flow distribution. Tribol. Ser. 31, 213–223 (1996)
Damiens, B., Lubrecht, A.A., Cann, P.M.E.: Lubrication regimes in rolling element bearings. Tribol. Ser. 39, 295–301 (2001)
Cann, P.M.E., Damiens, B., Lubrecht, A.A.: The transition between fully flooded and starved regimes in EHL. Tribol. Int. 37, 859–864 (2004)
Nagaraja, H.S., Sanborn, D.M., Winer, W.O.: Direct surface temperature measurement by infrared radiation in elastohydrodynamic contacts and the correlation with the blok flash temperature theory. Wear 49, 43–59 (1978)
Nagaraja, H.S., Sanborn, D.M., Winer, W.O.: Effects of load, speed, and surface roughness on sliding EHD contact temperatures. J. Lubr. Technol 99F, 254–263 (1997)
Crook, A.W.: The lubrication of rollers III: A theoretical discussion of friction and the temperatures in the oil film. Math. Phys. Sci. 254, 237–258 (1961)
Wen, S.Z.: Principles of Tribology, 1st edn. Tsinghua University Press, Beijing (1990)
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The work was financially supported by the International Science & Technology Cooperation Project (2011DFA70980) and the National Key Basic Research Program of China (2007CB607604 and 2009CB724404).
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Qian, S., Guo, D., Liu, S. et al. Experimental Investigation of Lubrication Failure of Polyalphaolefin Oil Film at High Slide/Roll Ratios. Tribol Lett 44, 107 (2011). https://doi.org/10.1007/s11249-011-9820-8
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DOI: https://doi.org/10.1007/s11249-011-9820-8