Title |
Mechanisms of antiwear tribofilm growth revealed in situ by single-asperity sliding contacts
|
---|---|
Published in |
Science, March 2015
|
DOI | 10.1126/science.1258788 |
Pubmed ID | |
Authors |
N N Gosvami, J A Bares, F Mangolini, A R Konicek, D G Yablon, R W Carpick |
Abstract |
Zinc dialkyldithiophosphates (ZDDPs) are widely used additives in automotive lubricants which form crucial antiwear tribofilms at sliding interfaces. The mechanisms governing the tribofilm growth are not well-understood, limiting the development of replacements with better performance and catalytic converter compatibility. Using atomic force microscopy in ZDDP-containing lubricant base stock at elevated temperatures, we monitor 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 are observed versus sliding time. The growth rate increases exponentially with either applied compressive stress or temperature, consistent with a thermally-activated, stress-assisted reaction rate model. The films grow regardless of the presence of iron on either the tip or substrate, highlighting the critical role of stress and thermal activation. |
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Demographic breakdown
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Science communicators (journalists, bloggers, editors) | 1 | 25% |
Mendeley readers
Geographical breakdown
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Researcher | 48 | 15% |
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Student > Bachelor | 14 | 4% |
Other | 44 | 14% |
Unknown | 62 | 20% |
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Physics and Astronomy | 25 | 8% |
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Other | 15 | 5% |
Unknown | 89 | 28% |