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Title: In situ probing of stress-induced nanoparticle dispersion and friction reduction in lubricating grease

Authors:
; ; ;
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
1396896
Grant/Contract Number:
AC02-05CH11231
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Tribology International
Additional Journal Information:
Journal Volume: 111; Journal Issue: C; Related Information: CHORUS Timestamp: 2017-10-04 15:48:55; Journal ID: ISSN 0301-679X
Publisher:
Elsevier
Country of Publication:
United Kingdom
Language:
English

Citation Formats

Sanchez, Carlos, Chen, Yunyun, Parkinson, Dilworth Y., and Liang, Hong. In situ probing of stress-induced nanoparticle dispersion and friction reduction in lubricating grease. United Kingdom: N. p., 2017. Web. doi:10.1016/j.triboint.2017.02.038.
Sanchez, Carlos, Chen, Yunyun, Parkinson, Dilworth Y., & Liang, Hong. In situ probing of stress-induced nanoparticle dispersion and friction reduction in lubricating grease. United Kingdom. doi:10.1016/j.triboint.2017.02.038.
Sanchez, Carlos, Chen, Yunyun, Parkinson, Dilworth Y., and Liang, Hong. 2017. "In situ probing of stress-induced nanoparticle dispersion and friction reduction in lubricating grease". United Kingdom. doi:10.1016/j.triboint.2017.02.038.
@article{osti_1396896,
title = {In situ probing of stress-induced nanoparticle dispersion and friction reduction in lubricating grease},
author = {Sanchez, Carlos and Chen, Yunyun and Parkinson, Dilworth Y. and Liang, Hong},
abstractNote = {},
doi = {10.1016/j.triboint.2017.02.038},
journal = {Tribology International},
number = C,
volume = 111,
place = {United Kingdom},
year = 2017,
month = 7
}

Journal Article:
Free Publicly Available Full Text
This content will become publicly available on March 8, 2018
Publisher's Accepted Manuscript

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  • This method covers the determination of the load-carrying properties of lubricating greases. Two determinations are made: load-wear index (formely called mean-hertz load), and weld point, by means of the four-ball extreme-pressure (EP) tester. The tester is operated with one steel ball under load rotating against three steel balls held stationary in the form of a cradle. The rotating speed is 1770 +- 60 rpm. Lubricating greases are brought to 27 +- 8/sup 0/C (80 +- 15/sup 0/F) and then subjected to a series of tests of 10-s duration at increasing loads until welding occurs. This method, used for specification purposes,more » differentiates between lubricating greases having low, medium, and high level of extreme-pressure properties. The results do not necessarily correlate with results from service. It is noted that lubricating greases that have as their fluid component a silicone, halogenated silicone, or a mixture comprising silicone fluid and petroleum oil, are not applicable to this method of test.« less
  • This method covers empirical determination of the consistency of small samples of lubricating greases by means of 1/4-scale cone or a 1/2-scale cone. The penetration of lubricating grease is determined at 77/sup 0/F (25/sup 0/C) by the extent of penetration of the cone into the sample for 5 s. This method is applicable to greases of National Lubricating Grease Institute (NLGI) Grades 0 to 4 and is intended for use only where the size of the sample limits the use of ASTM Method D 217, Test for Cone Penetration of Lubricating Grease.
  • One of the most important characteristics determining the quality of instrument components is the moment of resistance to bearing rotation, or frictional torque T{sub f}. This quantity, in turn, depends largely on the composition and properties of the lubricant. The work reported here was aimed at determining what parameters of grease (physicochemical properties, chemical nature of components) influence the magnitude of T{sub f} of bearings in video equipment. We prepared several series of grease samples for use in this investigation. In each series, one particular parameter was varied, in order to determine its specific influence on T{sub f}. The greasesmore » were tested in No. 4-1080096 ball bearings in an S-192 test stand at 20{degrees}C. The test conditions gave a complete simulation of the conditions of bearing operation in the video head section of video equipment: bearing rotation speed 1500 rpm, axial load 15 N. Measurements of T{sub f} for each grease sample were performed on 30 bearings; the results were computer-processed. The standard deviation of values of T{sub f} was (0.2-0.32) x 10{sup -4} N{sm_bullet}m. In order to determine how the viscosity of the dispersion medium influences the torque, we tested a series of grease samples based on poly-{alpha}-olefin oils (PAOO) with various viscosities, thickened with lithium stearate. The oil viscosity (20{degrees}C) was varied from 1.09 mm{sup 2}/sec (PAOO-7) to 543 mm{sup 2}/sec (PAOO-20). With increasing viscosity of the dispersion medium, the effective viscosity of the grease also increases.« less
  • The results of a study involving the laboratory production of lubricating grease from heavy oil extracted from the Nigerian tarsands are reported. Toluene-extracted oil from the tarsands was used in making a soap-based grease and a clay-based grease. The grease produced was then tested in accordance with the standard National Laboratory for Grease Institute (NLGI) specifications. The two types of grease produced from the tarsands oil conformed with the NLGI specifications and were in the category of grease suitable for use as lubricant for plain and roller bearings and as sealants.