Shu, J., Espejo, C., Kalin, M. et al. (1 more author) (2024) Synergism between bio-based oleate ester and low-concentration ZDDP under reciprocating contacts. Tribology International, 192. 109252. ISSN 0301-679X
Abstract
In this study, a bio-based ester was experimentally tested under a reciprocating contact in terms of the tribological performance to assess the potential of bio-based materials as boundary lubrication additives for low Sulphated Ash, Phosphorus, and Sulphur (SAPS) lubricants. A synergy in tribological performance has been observed when the ethyl oleate was used with a low concentration of ZDDP, showing both lower friction and wear loss, compared to only ethyl oleate or Zinc dialkyldithiophosphates (ZDDP) as single additives in base oil. SEM-EDX and ToF-SIMS analyses confirm that the additive combination of ester and low-concentration ZDDP generates a more evenly distributed tribo-film than that for only ZDDP as an additive. Although the tribo-film thickness of the ester/ZDDP lubricant combination, measured with AFM, issmaller than that for only low-concentration ZDDP, the combination shows superior wear protection ability over ZDDP. Mass spectra from ToF-SIMS show that the main component of the film formed by the additive combination is zinc polyphosphate, while the film generated from low-concentration ZDDP consists of short-chain iron phosphate. It is proposed that the ethyl oleate present in the additive combination alleviates severe shear in the contact, which promotes the formation of a uniform tribo-film composed of glassy zinc polyphosphate. The formed tribo-film enhances the adsorption of ester fragments, improving the tribological performance compared to using only ester as an additive. The obtained results demonstrate the potential of bio-based esters to reduce ZDDP usage and move towards greener lubricants.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2024 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC license (http://creativecommons.org/licenses/bync/4.0/). |
Keywords: | Bio-based ester; Ethyl oleate; Low -concentration ZDDP; Reciprocation |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Mechanical Engineering (Leeds) > Institute of Functional Surfaces (Leeds) |
Funding Information: | Funder Grant number EU - European Union 860246 |
Depositing User: | Symplectic Publications |
Date Deposited: | 05 Apr 2024 14:59 |
Last Modified: | 05 Apr 2024 14:59 |
Published Version: | https://www.sciencedirect.com/science/article/pii/... |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.triboint.2024.109252 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:211191 |
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