Low friction bio-inspired polydopamine/polytetrafluoroethylene coating performance in hydrodynamic bearings
Industrial Lubrication and Tribology
ISSN: 0036-8792
Article publication date: 31 December 2021
Issue publication date: 4 October 2022
Abstract
Purpose
Low friction polymer coatings able to withstand high loadings and many years of continuous operation are difficult to formulate at low cost, but could find many applications in industry. This study aims to analyze and compare friction and wear performance of novel polydopamine/polytetrafluoroethylene (PDA/PTFE) and traditional tin Babbitt coatings applied to an industrial journal bearing.
Design/methodology/approach
This paper tested PTFE based coating, co-deposited with PDA, a biopolymer allowing sea mussels to adhere to ocean rocks. This coating was deposited on flat steel substrates and on a curved cast iron hydrodynamic journal bearing surface. The flat substrates were analyzed with a tribometer and an optical microscope, while the coated bearing liners were tested in an industrial laboratory setting at different speeds and different radial loads.
Findings
PDA/PTFE coating showed 2-3 times lower friction compared to traditional tin Babbitt for flat substrates, but higher friction in the bearing liners. PDA/PTFE also showed considerable wear through coating delamination and abrasion in the bearing liners.
Research limitations/implications
Five future modifications to mitigate coating flaws are provided, which include modifications to coating thickness and its surface finish.
Originality/value
While the novel coating showed excellent results on flat substrates, coating performance in a large scale bearing was found to be poor. This study shows that coating preparation needs to be improved to avoid frictional losses and unwanted damage to bearings. We provide several routes that could improve coating performance in industrial applications.
Keywords
Acknowledgements
This material is based upon work supported by the U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy (EERE) under the Next Generation Electric Machines Award Number DE-EE0007874. The authors thank Craig Lipscomb for his kind assistance in bearing testing and Yogi Sharma for his guidance and expertise in bearing manufacture.
Disclaimer: This paper was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.
Citation
Rutkevičius, M., Dong, J., Tremelling, D., Viertel, J. and Beckford, S. (2022), "Low friction bio-inspired polydopamine/polytetrafluoroethylene coating performance in hydrodynamic bearings", Industrial Lubrication and Tribology, Vol. 74 No. 8, pp. 950-955. https://doi.org/10.1108/ILT-04-2021-0103
Publisher
:Emerald Publishing Limited
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