Modification of boundary lubrication by oil-soluble friction modifier additives

Yingxi Zhu, Hiroko Ohtani, Michael L. Greenfield, Marina Ruths, Steve Granick

Research output: Contribution to journalArticle


The molecular-level function of model and commercial friction modifier additives in lubricants of the type used at the wet clutch interface in automatic transmissions has been studied using a surface forces apparatus (SFA) modified for oscillatory shear. The nanorheological properties of tetradecane with and without a model friction modifier additive (1-hexadecylamine) were examined in the boundary lubrication regime and compared to a fully-formulated automatic transmission fluid (ATF). 1-Hexadecylamine adsorbed as a single layer on the sliding surfaces, reduced the static frictional force and the limiting shear stress, and eliminated the stick-slip transition that exists in pure tetradecane. The ATF, which contains commercial-grade friction modifiers, showed nanorheological properties similar to those observed for tetradecane containing 0.1-0.2 wt% 1-hexadecylamine.

Original languageEnglish (US)
Pages (from-to)127-134
Number of pages8
JournalTribology Letters
Issue number2
StatePublished - Aug 1 2003


  • Automatic transmission fluids
  • Friction modifiers
  • Molecular tribology
  • Nanorheology
  • Surface forces apparatus
  • Thin-film lubricating

ASJC Scopus subject areas

  • Chemical Engineering(all)
  • Mechanical Engineering

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  • Cite this

    Zhu, Y., Ohtani, H., Greenfield, M. L., Ruths, M., & Granick, S. (2003). Modification of boundary lubrication by oil-soluble friction modifier additives. Tribology Letters, 15(2), 127-134.