Morina, A, Zhao, H and Mosselmans, JFW (2014) In-situ reflection-XANES study of ZDDP and MoDTC lubricant films formed on steel and diamond like carbon (DLC) surfaces. Applied Surface Science, 297. 167 - 175. ISSN 0169-4332
Abstract
Chemical characterisation of boundary lubricated interfaces is essential for developing mechanistic models that describe lubricant additive interactions with the surface and their effect on tribological performance. In this study the potential for using the synchrotron-based reflection mode X-ray absorption spectroscopy (XAS) technique for in-situ chemical characterisation of lubricant films has been studied. Thermal films formed from zinc dialkyl dithio phosphate (ZDDP) and molybdenum dialkyl dithio carbamate (MoDTC) lubricant additives have been formed and analysed in-situ using the X-ray absorption near edge structure (XANES) spectroscopy technique. The surface sensitivity of this approach was improved by doing the analysis in reflection mode, enabling analysis of only top layer (up to around 10 nm) of the solid surface. In addition, in-lubro analysis of pre-formed tribofilms from the same additives was done using non-vacuum conditions. The results are discussed in conjunction with XANES and X-ray photoelectron spectroscopy (XPS) analysis of similar additives published in the literature. The results obtained are consistent with the existing ZDDP and MoDTC literature and provide some new insight into intermediate species not reported before. The advantages and disadvantages of the developed XANES methodology for in-situ surface chemical analysis of lubricated conditions are discussed.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | (c) 2014, Elsevier B.V. All rights reserved. This is an author produced version of a paper published in Applied Surface Science. Uploaded in accordance with the publisher's self-archiving policy |
Keywords: | Lubricant additives; Tribofilm; XANES; MoDTC; ZDDP |
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) |
Depositing User: | Symplectic Publications |
Date Deposited: | 10 Mar 2014 16:18 |
Last Modified: | 15 Sep 2014 01:52 |
Published Version: | http://dx.doi.org/10.1016/j.apsusc.2014.01.116 |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.apsusc.2014.01.116 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:77963 |