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Your search keyword '"Zhou, Huidi"' showing total 794 results
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794 results on '"Zhou, Huidi"'

164. Magnetron sputtering NbSe2film as lubricant for space current-carrying sliding contact

Author

Yang, Yang, Pei, Lulu, Zhang, Hongzhang, Feng, Kai, Ju, Pengfei, Duan, Wenshan, Ji, Li, Li, Hongxuan, Liu, Xiaohong, Zhou, Huidi, and Chen, Jianmin

Abstract

This study demonstrates that magnetron-sputtered NbSe2film can be used as a lubricant for space current-carrying sliding contact, which accommodates both metal-like conductivity and MoS2-like lubricity. Deposition at low pressure and low energy is performed to avoid the generation of the interference phase of NbSe3. The composition, microstructure, and properties of the NbSe2films are further tailored by controlling the sputtering current. At an appropriate current, the film changed from amorphous to crystalline, maintained a dense structure, and exhibited excellent comprehensive properties. Compared to the currently available electrical contact lubricating materials, the NbSe2 film exhibits a significant advantage under the combined vacuum and current-carrying conditions. The friction coefficient decreases from 0.25 to 0.02, the wear life increases more than seven times, and the electric noise reduces approximately 50%.

Published
2023
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169. Role of nanoparticles in achieving macroscale superlubricity of graphene/nano-SiO2 particle composites.

Author

Li, Panpan, Ji, Li, Li, Hongxuan, Chen, Lei, Liu, Xiaohong, Zhou, Huidi, and Chen, Jianmin

Subjects
NANODIAMONDS, DIAMOND-like carbon, NANOPARTICLES, COMPOSITE coating, SHEARING force, GRAPHENE
Abstract

Recent studies have reported that adding nanoparticles to graphene enables macroscale superlubricity to be achieved. This study focuses on the role of nanoparticles in achieving superlubricity. First, because graphene nanoscrolls can be formed with nanoparticles as seeds under shear force, the applied load (or shear force) is adjusted to manipulate the formation of graphene nanoscrolls and to reveal the relationship between graphene-nanoscroll formation and superlubricating performance. Second, the load-carrying role of spherical nano-SiO2 particles during the friction process is verified by comparison with an elaborately designed fullerene that possesses a hollow-structured graphene nanoscroll. Results indicate that the incorporated nano-SiO2 particles have two roles in promoting the formation of graphene nanoscrolls and exhibiting load-carrying capacity to support macroscale forces for achieving macroscale superlubricity. Finally, macroscale superlubricity (friction coefficient: 0.006–0.008) can be achieved under a properly tuned applied load (2.0 N) using a simple material system in which a graphene/nano-SiO2 particle composite coating slides against a steel counterpart ball without a decorated diamond-like carbon film. The approach described in this study could be of significance in engineering. [ABSTRACT FROM AUTHOR]

Published
2022
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198. Effect of Melting Behavior of Al2O3 Powder on the Structure and Dielectric Properties of Plasma-Sprayed Coatings.

Author

Bu, Zhenyu, Zhao, Xiaoqin, Liu, Libin, Xue, Yun, An, Yulong, and Zhou, Huidi

Subjects
DIELECTRIC properties, DIELECTRIC strength, DIELECTRIC breakdown, ALUMINUM oxide, SURFACE coatings, ALLOY powders, POWDERS
Abstract

Depositing an Al2O3 insulating coating on the inner or outer ring of a bearing can effectively prevent shaft current from passing through it, thereby preventing electrical deterioration. Herein, the effect of spraying parameters on the temperature and velocity of in-flight Al2O3 powder particles, the morphology of the resultant splats, and the microhardness and dielectric characteristics of related coatings were thoroughly investigated. The results reveal that the densest Al2O3 coatings with a porosity of 3.43% can be achieved when the powders are thoroughly melted in the plasma flame without over-melting. Otherwise, porosities and microdefects increased in coatings deposited by semi-molten or over-molten powders. Moreover, due to the higher density, the dielectric strength of the sealed coating is greatly boosted. The number of defects (particularly longitudinal cracks) in the coating is the major reason for the decrease in dielectric strength. Furthermore, the increase in coating thickness significantly reduces the dielectric strength of the coating, which should be attributed to the increase in the number of defects generated by the thickness increase. The essence of dielectric breakdown of the Al2O3 coating is the combined mechanisms of corona discharge and thermal breakdown, and the corresponding dielectric breakdown model was constructed. [ABSTRACT FROM AUTHOR]

Published
2022
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