Effect of Contamination on the Friction and Wear of Carboxylic Acids in Aqueous Lubricants
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The friction and wear mechanisms of water-based fluids consisting of various types of carboxylic acids have been systematically investigated using a ball-on-disc tribometer on a super duplex stainless steel under boundary lubricating conditions. Under water-based lubrication, a decrease in friction was found for each of the tested carboxylic acids with a hydrocarbon chain longer than 12 carbon atoms. However, wear reduction was only seen for the carboxylic acids with a hydrocarbon chain longer than 16 carbon atoms or with shorter chain carboxylic acids in concentrations above a critical value. In addition, it was found that when the lubricant is contaminated with bivalent metal ions like Ca2+ or Mg2+, the frictional performance worsened; however, wear improved. Increasing the concentration of bivalent alkaline metal ions reduced the adsorption ability of carboxylic acids to the steel surface leading to higher friction and the presence of Na+ ions facilitated the wear improvement. This is explained by the formation of polyelectrolyte complexes between the metal ions dissolved in the lubricant and the carboxylic acid molecules. To compensate for the detrimental effects in friction, a chelating strategy has been implemented and explained in detail.
KeywordsFriction Wear Lubrication Chelation Carboxylic acids Seawater
This research was sponsored by the Norwegian Research Council (NFR NANO2021). The Research Council of Norway is also acknowledged for the support provided to the Norwegian Micro- and Nano-Fabrication Facility, NorFab.
- 1.Von der Ohe, C.B., Johnsen, R., Espallargas, N.: Hydraulic cylinders for offshore splash zone operation—a review of piston rod failure cases and alternative concepts. In: International Conference on Ocean, Offshore and Arctic Engineering. pp. 1–14., Honolulu (2009)Google Scholar
- 2.United States Environmental Protection Agency: Environmentally Acceptable Lubricants (2011)Google Scholar
- 9.Greaves, M.R.: Water/glycol hydraulic fluids, US20100197539A1, (2007)Google Scholar
- 13.Totten, G.E., Negri, V.J., De (eds.): Handbook of Hydraulic Fluid Technology. CRC Press, Taylor & Francis Group, Boca Raton (2012)Google Scholar
- 21.Mukerjee, P., Mysels, K.J.: Critical micelle concentrations of aqueous surfactant systems, Washington (1972)Google Scholar
- 24.Loehlé, S., Matta, C., Minfray, C., Mogne, T.L., Iovine, R., Obara, Y., Miyamoto, A., Martin, J.M.: Mixed lubrication of steel by C18 fatty acids revisited. Part I: toward the formation of carboxylate. Tribol. Int. 82, 218–227 (2015). https://doi.org/10.1016/j.triboint.2014.10.020 CrossRefGoogle Scholar
- 30.Gsponer, N.S., Spesia, M.B., Durantini, E.N.: Effects of divalent cations, EDTA and chitosan on the uptake and photoinactivation of Escherichia coli mediated by cationic and anionic porphyrins. Photodiagn. Photodyn. Ther. 12, 67–75 (2015). https://doi.org/10.1016/j.pdpdt.2014.12.004 CrossRefGoogle Scholar