Imperial College London
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ProfessorHughSpikes

Faculty of Engineering, Department of Mechanical Engineering

Professor
 
 
 
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Contact

 

+44 (0)20 7594 7063h.spikes

 
 
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Assistant

 

Mrs Chrissy Stevens +44 (0)20 7594 7064

 
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Location

 

673City and Guilds BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Ueda:2022:10.1080/10402004.2021.1940407,
author = {Ueda, M and Spikes, H and Kadiric, A},
doi = {10.1080/10402004.2021.1940407},
journal = {Tribology Transactions},
pages = {1--21},
title = {Influence of black oxide coating on micropitting and ZDDP tribofilm formation},
url = {http://dx.doi.org/10.1080/10402004.2021.1940407},
volume = {65},
year = {2022}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Micropitting is a type of surface fatigue damage that occurs in rolling-sliding contacts operating under thin oil film conditions. Application of black oxide (BO) coating to steel rubbing surfaces has been suggested as a potential approach to alleviate micropitting. This paper confirms that BO coatings can prevent micropitting and identifies the predominant mechanism by which this occurs.Micropitting tests were carried out using ZDDP solutions in a ball on disc tribometer. Micropitting was preferentially generated on the smooth balls and this was completely prevented by applying a BO coating to the rougher discs, regardless of whether the balls were coated or not. In contrast, when the rough discs were not BO-coated, micropitting was consistently generated on both BO-coated and uncoated balls. BO coating has about one quarter the hardness of the steel used and was found to be very rapidly removed from the surface asperity peaks at the onset of rubbing, despite the presence of ZDDP. This resulted in an almost immediate and very large reduction of the surface roughness of the discs and this prevented high asperity stresses that would normally initiate and propagate the surface fatigue cracks leading to micropitting. Parallel measurement showed that BO did not suppress tribofilm growth, so the ZDDP was able to protect against adhesive wear while not promoting micropitting. The insights presented here can help with the design of components and lubricants that are effective in controlling both sliding wear and micropitting.
AU  - Ueda,M
AU  - Spikes,H
AU  - Kadiric,A
DO  - 10.1080/10402004.2021.1940407
EP  - 21
PY  - 2022///
SN  - 1040-2004
SP  - 1
TI  - Influence of black oxide coating on micropitting and ZDDP tribofilm formation
T2  - Tribology Transactions
UR  - http://dx.doi.org/10.1080/10402004.2021.1940407
UR  - https://www.tandfonline.com/doi/full/10.1080/10402004.2021.1940407
UR  - http://hdl.handle.net/10044/1/92347
VL  - 65
ER  -
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