Interfacial friction evolution between DLC film and sealing NBR on the plunger of fracturing pump based on molecular dynamics simulation
Abstract
Purpose
Two friction models of Fe-Fe and Diamond-like carbon (DLC)-Fe were established by molecular dynamics (MD) method to simulate the friction behavior of traditional fracturing pump plunger and new DLC plunger from atomic scale. This paper aims to investigate the effects of temperature and load on the friction behavior between sealed nitrile butadiene rubber (NBR) and DLC films.
Design/methodology/approach
In this study, MD method is used to investigate the friction behavior and mechanism of DLC film on plungers and sealing NBR based on Fe-Fe system and DLC-Fe system.
Findings
The results show that the friction coefficient of DLC-Fe system exhibits a downward trend with increasing load and temperature. And even achieve a superlubricity state of 0.005 when the load is 1 GPa. Further research revealed that the low interaction energy between DLC and NBR promoted the proportion of atoms with larger shear strain in NBR matrix and the lower Fe layer in DLC-Fe system to be much lower than that in Fe-Fe system. In addition, the application of DLC film can effectively inhibit the temperature rise of friction interface, but will occur relatively large peak velocity.
Originality/value
In this paper, two MD models were established to simulate the friction behavior between fracturing pump plunger and sealing rubber. Through the analysis of mean square displacement, atomic temperature, velocity and Interaction energy, it can be seen that the application of DLC film has a positive effect on reducing the friction of NBR.
Keywords
Acknowledgements
Funding: The authors are grateful for the financial support from the National Natural Science Foundation of China (52104037), the China Postdoctoral Science Foundation (2020TQ0251 and 2020M683358) and the Sichuan Province Science and Technology Support Program (2022NSFSC1985), the Collaborative Project of Sichuan Nanchong (23XNSYSX0040).
Declaration of competing interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Data availability statements: Due to the nature of this research, participants of this study did not agree for their data to be shared publicly, so supporting data is not available.
Citation
Liu, Y., Xu, P., Zhu, X., Liu, L., Li, B. and Li, Q. (2024), "Interfacial friction evolution between DLC film and sealing NBR on the plunger of fracturing pump based on molecular dynamics simulation", Industrial Lubrication and Tribology, Vol. ahead-of-print No. ahead-of-print. https://doi.org/10.1108/ILT-06-2024-0220
Publisher
:Emerald Publishing Limited
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