Consistency-dependent optical properties of lubricating grease studied by terahertz spectroscopy
Tian Lu(田璐)a)b),Zhou Qing-Li(周庆莉)c),Zhao Kun(赵昆)a)b)†, Shi Yu-Lei(施宇蕾)c),Zhao Dong-Mei(赵冬梅)c),Zhao Song-Qing(赵嵩卿)b), Zhao Hui(赵卉)b), Bao Ri-Ma(宝日玛)b),Zhu Shou-Ming(朱守明) b), Miao Qing(苗青)b),and Zhang Cun-Lin(张存林)c)
aState Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing 102249, China; bCollege of Science, China University of Petroleum, Beijing 102249, China; cBeijing Key Laboratory for Terahertz Spectroscopy and Imaging, Key Laboratory of Terahertz Optoelectronics, Ministry of Education, Department of Physics, Capital Normal University, Beijing 100048, China
Abstract The optical properties of four kinds of lubricating greases (urea, lithium, extreme pressure lithium, molybdenum disulfide lithium greases) with different NLGL (National Lubricant Grease Institute of America) numbers were investigated using terahertz time-domain spectroscopy. Greases with different NLGL grades have unique spectral features in the terahertz range. Comparison of the experimental data with predictions based on Lorentz–Lorenz theory exhibited that the refractive indices of each kind of lubricating grease were dependent on the their consistency. In addition, molybdenum disulfide (MoS2) as a libricant additive shows strong absorption from 0.2 to 1.4 THz, leading to higher absorption of MoS2-lithium grease than that of lithium grease.
(Specific materials: fabrication, treatment, testing, and analysis)
Fund: Project supported by the New Century Excellent Talents in University (Grant No. NCET-08-0841), the National Natural Science Foundation of China (Grant Nos. 60778034, 60877038, and 10804077), the Beijng Natural Science Foundation (Grant No. 4082026), the Research Fund for the Doctoral Program of Higher Education (Grant No. 200804250006), and the State Key Laboratory of Heavy Oil Processing, China University of Petroleum (Grant No. 2008-14).
Cite this article:
Tian Lu(田璐), Zhou Qing-Li(周庆莉), Zhao Kun(赵昆), Shi Yu-Lei(施宇蕾), Zhao Dong-Mei(赵冬梅), Zhao Song-Qing(赵嵩卿), Zhao Hui(赵卉), Bao Ri-Ma(宝日玛), Zhu Shou-Ming(朱守明), Miao Qing(苗青), and Zhang Cun-Lin(张存林) Consistency-dependent optical properties of lubricating grease studied by terahertz spectroscopy 2011 Chin. Phys. B 20 010703
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