Gosvami, NN, Bares, JA, Mangolini, F et al. (3 more authors) (2015) Mechanisms of antiwear tribofilm growth revealed in situ by single-asperity sliding contacts. Science, 348 (6230). 102 - 106. ISSN 0036-8075
Abstract
Zinc dialkyldithiophosphates (ZDDPs) form antiwear tribofilms at sliding interfaces and are widely used as additives in automotive lubricants. The mechanisms governing the tribofilm growth are not well understood, which limits the development of replacements that offer better performance and are less likely to degrade automobile catalytic converters over time. Using atomic force microscopy in ZDDP-containing lubricant base stock at elevated temperatures, we monitored the growth and properties of the tribofilms in situ in well-defined single-asperity sliding nanocontacts. Surface-based nucleation, growth, and thickness saturation of patchy tribofilms were observed. The growth rate increased exponentially with either applied compressive stress or temperature, consistent with a thermally activated, stress-assisted reaction rate model. Although some models rely on the presence of iron to catalyze tribofilm growth, the films grew regardless of the presence of iron on either the tip or substrate, highlighting the critical role of stress and thermal activation.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2015, The Author(s). This is the author’s version of the work. It is posted here by permission of the AAAS for personal use, not for redistribution. The definitive version was published in Science, Vol 348, on 3 Apr 2015, DOI: 10.1126/science.1258788. |
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) |
Depositing User: | Symplectic Publications |
Date Deposited: | 17 Nov 2015 15:14 |
Last Modified: | 17 Jan 2018 19:06 |
Published Version: | http://dx.doi.org/10.1126/science.1258788 |
Status: | Published |
Publisher: | American Association for the Advancement of Science |
Identification Number: | 10.1126/science.1258788 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:91820 |