Spatial pressure variations in synthetic lubricants contained in a static high-pressure diamond anvil cell (DAC), as well as in a loaded model bearing contact device, have been measured using the frequency shift of the lubricant’s Raman vibrational modes. Long-lived pressure fluctuations of ±0.5 GPa, with a relaxation time of several days, are observed m the static high pressure systems at an average pressure of 2.5 GPa. Evidence for rapidly varying pressure fluctuations in a concentrated contact is inferred from the increase in lubricant Raman linewidths. These results raise questions about key assumptions made in modeling EHD contacts. It is suggested that the present results are closely linked to recent observations of shear localization made by Winer and Bair.
1.
Alsaad
M.
Bair
S.
Sanborn
D. M.
Winer
W. O.
1978
, “Glass Transitions in Lubricants: Its Relation to EHD Lubrication
,” ASME JOURNAL OF LUBRICATION TECHNOLOGY
, Vol. 100
, No. 2
, pp. 404
–417
.2.
Bair
S.
Qureshi
F.
Winer
W. O.
1993
, “Observations of Shear Localization in Liquid Lubricants Under Pressure
,” ASME JOURNAL OF TRIBOLOGY
, Vol. 115
, pp. 507
–514
.3.
Ben-Amotz
D.
Lee
M.-R.
Cho
S. Y.
List
D. J.
1992
, “Solvent and Pressure Induced Perturbations of the Vibrational Potential Surface of Acetonitrile
,” J. Chem. Phys.
, Vol. 96
, pp. 8781
–8792
.4.
Bezot
P.
Hesse-Bezot
C.
Berthe
D.
Dalmaz
G.
Vergne
P.
1986
, “Viscoelastic Parameters of 5P4E as a Function of Pressure and Temperature by Light Scattering Technique
,” ASME JOURNAL OF TRIBOLOGY
, Vol. 108
, pp. 579
–583
.5.
Cann
P. M.
Spikes
H. A.
1989
, “Determination of the Shear Stresses of Lubricants in Elastohydrodynamic Contacts
,” STLE Tribology Transactions
, Vol. 32
, pp. 414
–422
.6.
Cann
P. M.
Spikes
H. A.
1991
, “In Lubro Studies of Lubricants in EHD Contacts Using FTIR Absorption Spectroscopy
,” STLE Tribological Transactions
, Vol. 34
, No. 2
, pp. 248
–256
.7.
Carson
G.
Hu
H-W.
Granick
S.
1992
, “Molecular Tribology of Fluid Lubrication: Shear Thinning
,” STLE Tribology Transactions
, Vol. 35
, No. 3
, pp. 405
–410
.8.
Dow
T. A.
Stockwell
R. D.
Kannel
J. W.
1987
, “Thermal Effects in Rolling/Sliding EHD Contacts: Part I—Experimental Measurements of Surface Pressure and Temperature
,” ASME JOURNAL OF TRIBOLOGY
, Vol. 109
, pp. 503
–511
.9.
Evans
C. E.
Song
Q.
Bohn
P. W.
1994
, “Spectral Lineshape in Extended Two-Dimensional Electronic Systems
,” J. Coll. Int. Sci.
, Vol. 166
, pp. 95
–101
.10.
Feng
R.
Ramesh
K. T.
1993
, “The Rheology of Lubricants at High Shear Rates
,” ASME JOURNAL OF TRIBOLOGY
, Vol. 115
, pp. 640
–649
.11.
Forman
R. A.
Piermarini
G. J.
Barnett
J. D.
Block
S.
1972
, “Pressure Measurement Made by the Utilization of Ruby Sharp-Line Luminescence
,” Science
, Vol. 176
, No. 4032
, pp. 284
–285
.12.
Gardiner
D. J.
Baird
E.
Gorvin
A. C.
Marshall
W. E.
Dare-Edwards
M. P.
1983
, “Raman Spectra of Lubricants in Elastohydrodynamic Entrapments
,” Wear
, Vol. 91
, pp. 111
–114
.13.
Gardiner
D. J.
Bowden
M.
Daymond
J.
Gorvin
A. C.
Dare-Edwards
M. P.
1984
, “A Raman Microscope Technique for Studying Liquids in a Diamond Anvil Cell
,” Appl. Spectrosc.
, Vol. 38
, pp. 282
–284
.14.
Gardiner
D. J.
Baird
E. M.
Craggs
C.
Dare-Edwards
M. P.
Bell
J. C.
1989
, “Raman Microspectroscopy of a Working Elastohydrodynamic Contact
,” Lubrication Science
, Vol. 1
, pp. 301
–313
.15.
Hamilton
G. M.
Moore
S. L.
1971
, “Deformation and Pressure in an Elastohydrodynamic Contact
,” Proc. Roy. Soc., London, Series A
, Vol. 322
, No. 1550
, pp. 313
–330
.16.
Hutchinson
E. J.
Shu
D.
LaPlant
F.
Ben-Amotz
D.
1995
, “Measurement of Fluid Film Thickness on Curved Surfaces by Raman Spectroscopy
,” Appl. Spectrosc.
, Vol. 49
, No. 9
, pp. 1275
–1278
.17.
Jayaraman
A.
1983
, “Diamond Anvil Cell and High-Pressure Physical Investigations
,” Rev. Mod. Phys.
, Vol. 55
, No. 1
, pp. 65
–108
.18.
Jayaraman
A.
1986
, “Ultrahigh Pressures
,” Rev. Set Instrum.
, Vol. 57
, No. 6
, pp. 1013
–1031
.19.
Kip
B. J.
Meier
R. J.
1990
, “Determination of Local Temperature at a Sample during Raman Experiments Using Stokes and Anti-Stokes Raman Bands
,” Appl. Spectrosc.
, Vol. 44
, No. 4
, pp. 707
–711
.20.
LaPlant
F.
Ben-Amotz
D.
1995
, “Design and construction of a microscope-based Raman system
,” Rev. Sci. Instrum.
, Vol. 66
, No. 6
, pp. 3537
–3544
.21.
Lauer
J. L.
Peterkin
M. E.
1977
, “Traction and Lubricant Film Temperature as Related to the Glass Transition Temperature and Solidification
,” ASLE Transactions
, Vol. 21
, pp. 250
–256
.22.
Lauer
J. E.
Keller
L. E.
Choi
F. H.
King
V. W.
1982
, “Alignment of Fluid Molecules in an EHD Contact
,” ASLE Transactions
, Vol. 25
, No. 3
, pp. 329
–336
.23.
Lauer
J. L.
Ahn
Y-J.
1987
, “Lubricants and Lubricant Additives Under Shear Studied Under Operating Conditions by Optical and Infrared Spectroscopic Methods
,” STLE Transactions
, Vol. 31
, No. 1
, pp. 120
–127
.24.
Malyj
M.
Griffiths
J. E.
1983
, “Stokes/Anti-Stokes Raman Vibrational Temperatures: Reference Materials, Standard Lamps, and Spectrophotometric Calibrations
,” Appl. Spectrosc.
, Vol. 37
, No. 4
, pp. 315
–333
.25.
Ramesh
K. T.
1991
, “The Short-Time Compressibility of Elastohydrodynamic Lubricants
,” ASME JOURNAL OF TRIBOLOGY
, Vol. 113
, pp. 361
–371
.26.
Sharma
S. K.
Mao
H. K.
Bell
P. M.
Xu
J.
1985
, “Measurement of Stress in Diamond Anvils with Micro-Raman Spectroscopy
,” J. Raman Spectrosc.
, Vol. 16
, No. 5
, pp. 350
–352
.27.
Smith
F. W.
1960
, “Lubricant Behavior in Concentrated Contact—Some Rheological Problems
,” ASLE Transactions
, Vol. 3
, pp. 18
–25
.
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