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Optimization of depositing uniform and wear-resistant diamond films on massive mechanical seals

Yun He (School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai, China)
Fanghong Sun (School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai, China)
Xuelin Lei (School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai, China)

Industrial Lubrication and Tribology

ISSN: 0036-8792

Article publication date: 8 January 2018

Abstract

Purpose

This study aims to obtain diamond-coated mechanical seals with improved sealing performance and considerable cost. To achieve this purpose, the study focuses on depositing uniform, wear-resistant and easily polished diamond coatings on massive mechanical seals in a large-scale vacuum chamber.

Design/methodology/approach

The computational fluid dynamics simulation test and its corresponding deposition experiment are carried out to improve the uniformity of diamond films on massive mechanical seals. The polishing properties and sealing performance of mechanical seals coated with three different diamond films (microcrystalline diamond [MCD], nanocrystalline diamond [NCD] and microcrystalline/nanocrystalline diamond [MNCD]) and uncoated mechanical seals are comparatively studied using the polishing tests and dynamic seal tests to obtain the optimized diamond coating type on the mechanical seals.

Findings

The substrate rotation and four gas outlets distribution are helpful for depositing uniform diamond coatings on massive mechanical seals. The MNCD-coated mechanical seal shows the advantages of high polishing efficiency in the initial polishing process and excellent wear resistance and self-lubrication property in the follow-up polishing period because of its unique composite diamond film structures. The MNCD-coated mechanical seal shows the longest working life under dry friction condition, about 14, 1.27 and 1.9 times of that for the uncoated, MCD and NCD coated mechanical seals, respectively.

Originality/value

The effect of substrate rotation and gas outlets distribution on temperature and gas flow field during diamond deposition procedure is simulated. The MNCD-coated mechanical seal exhibits a superior sealing performance compared with the MCD-coated, NCD-coated and uncoated mechanical seals, which is helpful for decreasing the operating system shut-down frequency and saving operating energy consumption.

Keywords

Acknowledgements

This research is supported by the National Science Foundation of China (No. 51705155), the China Postdoctoral Science Foundation (No. 2016M591614), the Shanghai Sailing Program (17YF1403100) and the Fundamental Research Funds for the Central Universities (No. 222201514314).

Citation

He, Y., Sun, F. and Lei, X. (2018), "Optimization of depositing uniform and wear-resistant diamond films on massive mechanical seals", Industrial Lubrication and Tribology, Vol. 70 No. 1, pp. 97-104. https://doi.org/10.1108/ILT-02-2017-0028

Publisher

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Emerald Publishing Limited

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