Understanding the pressure and shear dependence of viscosity is essential to an understanding of the mechanisms of film forming and friction in concentrated contacts. The blending of different molecular mass polyalphaolefins (PAOs) may permit the formulator to arrive at a desired combination of film thickness and friction. The viscosities of PAO base oils and their blends were measured versus temperature, pressure, and shear stress to 1 GPa in pressure. The Grunberg–Nissan mixing rule, with effective mole fractions, provides an excellent mixing rule for the temperature and pressure-dependent low-shear viscosity. This work provides the first look at a possible mixing rule for the non-Newtonian response of mixtures of base oils.

References

References
1.
Bair
,
S.
,
Fernandez
,
J.
,
Khonsari
,
M. M.
,
Krupka
,
I.
,
Qureshi
,
F.
,
Vergne
,
P.
, and
Wang
,
Q. J.
,
2009
, “
Letter to the Editor
,”
Proc. Inst. Mech. Eng., Part J: J. Eng. Tribol.
,
223
(
4
), pp.
1
2
.
2.
Hutton
,
J. F.
, and
Phillips
,
M. C.
,
1973
, “
High Pressure Viscosity of a Polyphenyl Ether Measured With a New Couette Viscometer
,”
Nature
,
245
(
140
), pp.
15
16
.
3.
Vergne
,
P.
, and
Bair
,
S.
,
2014
, “
Classical EHL Versus Quantitative EHL: A Perspective—Part I: Real Viscosity-Pressure Dependence and the Viscosity-Pressure Coefficient for Predicting Film Thickness
,”
Tribol. Lett.
,
54
(
1
), pp.
1
12
.
4.
Bair
,
S.
,
Martinie
,
L.
, and
Vergne
,
P.
,
2016
, “
Classical EHL versus Quantitative EHL: A Perspective—Part II: Super-Arrhenius Piezoviscosity, an Essential Component of Elastohydrodynamic Friction Missing From Classical EHL
,”
Tribol. Lett.
,
63
(
3
), p.
37
.
5.
Liu
,
Y.
,
Wang
,
Q. J.
,
Bair
,
S.
, and
Vergne
,
P.
,
2007
, “
A Quantitative Solution for the Full Shear-Thinning EHL Point Contact Problem Including Traction
,”
Tribol. Lett.
,
28
(
2
), pp.
171
181
.
6.
Jang
,
J. Y.
,
Khonsari
,
M. M.
, and
Bair
,
S.
,
2007
, “
On the Elastohydrodynamic Analysis of Shear-Thinning Fluids
,”
Proc. R. Soc. London A: Math., Phys. Eng. Sci.
,
463
(
2088
), pp.
3271
3290
.
7.
Krupka
,
I.
,
Bair
,
S.
,
Kumar
,
P.
,
Khonsari
,
M. M.
, and
Hartl
,
M.
,
2009
, “
An Experimental Validation of the Recently Discovered Scale Effect in Generalized Newtonian EHL
,”
Tribol. Lett.
,
33
(
2
), pp.
127
135
.
8.
Martini
,
A.
, and
Bair
,
S.
,
2010
, “
The Role of Fragility in EHL Entrapment
,”
Tribol. Int.
,
43
(
1–2
), pp.
277
282
.
9.
Krupka
,
I.
,
Kumar
,
P.
,
Bair
,
S.
,
Khonsari
,
M. M.
, and
Hartl
,
M.
,
2010
, “
The Effect of Load (Pressure) for Quantitative EHL Film Thickness
,”
Tribol. Lett.
,
37
(
3
), pp.
613
622
.
10.
Habchi
,
W.
,
Vergne
,
P.
,
Bair
,
S.
,
Andersson
,
O.
,
Eyheramendy
,
D.
, and
Morales-Espejel
,
G. E.
,
2010
, “
Influence of Pressure and Temperature Dependence of Thermal Properties of a Lubricant on the Behaviour of Circular TEHD Contacts
,”
Tribol. Int.
,
43
(
10
), pp.
1842
1850
.
11.
Habchi
,
W.
,
Bair
,
S.
, and
Vergne
,
P.
,
2013
, “
On Friction Regimes in Quantitative Elastohydrodynamics
,”
Tribol. Int.
,
58
, pp.
107
117
.
12.
Habchi
,
W.
,
Bair
,
S.
,
Qureshi
,
F.
, and
Covitch
,
M.
,
2013
, “
A Film Thickness Correction Formula for Double-Newtonian Shear-Thinning in Rolling EHL Circular Contacts
,”
Tribol. Lett.
,
50
(
1
), pp.
59
66
.
13.
Björling
,
M.
,
Habchi
,
W.
,
Bair
,
S.
,
Larsson
,
R.
, and
Marklund
,
P.
,
2013
, “
Towards the True Prediction of EHL Friction
,”
Tribol. Int.
,
66
, pp.
19
26
.
14.
Björling
,
M.
,
Habchi
,
W.
,
Bair
,
S.
,
Larsson
,
R.
, and
Marklund
,
P.
,
2014
, “
Friction Reduction in Elastohydrodynamic Contacts by Thin-Layer Thermal Insulation
,”
Tribol. Lett.
,
53
(
2
), pp.
477
486
.
15.
Ewen
,
J. P.
,
Gattinoni
,
C.
,
Zhang
,
J.
,
Heyes
,
D. M.
,
Spikes
,
H. A.
, and
Dini
,
D.
,
2017
, “
On the Effect of Confined Fluid Molecular Structure on Nonequilibrium Phase Behaviour and Friction
,”
Phys. Chem. Chem. Phys.
,
19
(
27
), pp.
17883
17894
.
16.
Comuñas
,
M. J.
,
Paredes
,
X.
,
Gaciño
,
F. M.
,
Fernández
,
J.
,
Bazile
,
J. P.
,
Boned
,
C.
,
Daridon
,
J. L.
,
Galliero
,
G.
,
Pauly
,
J.
, and
Harris
,
K. R.
,
2014
, “
Viscosity Measurements for Squalane at High Pressures to 350 MPa From T=(293.15 to 363.15) K
,”
J. Chem. Thermodyn.
,
69
, pp.
201
208
.
17.
Bair
,
S.
,
Mary
,
C.
,
Bouscharain
,
N.
, and
Vergne
,
P.
,
2013
, “
An Improved Yasutomi Correlation for Viscosity at High Pressure
,”
Proc. Inst. Mech. Eng., Part J: J. Eng. Tribol.
,
227
(
9
), pp.
1056
1070
.
18.
Bair
,
S.
,
2007
,
High-Pressure Rheology for Quantitative Elastohydrodynamics
,
Elsevier Science
,
Amsterdam, The Netherlands
, p.
235
; pp. 143–150.
19.
Bair
,
S.
,
2001
, “
Ordinary Shear-Thinning Behavior in Liquids and Its Effect Upon EHL Traction
,”
Tribology Research: From Model Experiment to Industrial Problem: A Century of Efforts in Mechanics, Materials Science and Physico-Chemistry (Tribology Series)
, Vol.
39
,
Elsevier
, Amsterdam, The Netherlands, pp.
733
742
.
20.
Bair
,
S.
, and
Kotzalas
,
M.
,
2006
, “
The Contribution of Roller Compliance to Elastohydrodynamic Traction
,”
Tribol. Trans.
,
49
(
2
), pp.
218
224
.
21.
Diogo
,
J. C.
,
Avelino
,
H. M.
,
Caetano
,
F. J.
, and
Fareleira
,
J. M.
,
2014
, “
Tris (2-Ethylhexyl) Trimellitate (TOTM) a Potential Reference Fluid for High Viscosity—Part I: Viscosity Measurements at Temperatures From (303 to 373) K and Pressures Up to 65 MPa, Using a Novel Vibrating-Wire Instrument
,”
Fluid Phase Equilibria
,
384
, pp.
50
59
.
22.
Bair, S., 2000, “
Pressure-Viscosity Behavior of Lubricants to 1.4 GPa and its Relation to EHD Traction
,”
Tribol. Trans.
,
43
(1), pp. 91–99.
23.
Grunberg
,
L.
, and
Nissan
,
A. H.
,
1949
, “
Mixture Law for Viscosity
,”
Nature
,
164
(
4175
), p.
799
.
24.
Bair
,
S.
,
Habchi
,
W.
,
Baker
,
M.
, and
Pallister
,
D. M.
,
2017
, “
Quantitative Elastohydrodynamic Film-Forming for an Oil/Refrigerant System
,”
ASME J. Tribol.
,
139
(
6
), p.
061501
.
25.
Jain
,
P.
, and
Singh
,
M.
,
2004
, “
Density, Viscosity, and Excess Properties of Binary Liquid Mixtures of Propylene Carbonate With Polar and Nonpolar Solvents
,”
J. Chem. Eng. Data
,
49
(
5
), pp.
1214
1217
.
26.
Bair
,
S.
,
2018
, “
Generalized Newtonian Viscosity Functions for Hydrodynamic Lubrication
,”
Tribol. Int.
,
117
, pp.
15
23
.
27.
Bair
,
S.
,
Vergne
,
P.
, and
Querry
,
M.
,
2005
, “
A Unified Shear-Thinning Treatment of Both Film Thickness and Traction in EHD
,”
Tribol. Lett.
,
18
(
2
), pp.
145
152
.
28.
Bair
,
S.
, and
Winer
,
W. O.
,
2007
, “
A Quantitative Test of the Einstein–Debye Relation Using the Shear Dependence of Viscosity for Low Molecular Weight Liquids
,”
Tribol. Lett.
,
26
(
3
), p.
223
.
29.
Liu
,
P.
,
Yu
,
H.
,
Ren
,
N.
,
Lockwood
,
F. E.
, and
Wang
,
Q. J.
,
2015
, “
Pressure–Viscosity Coefficient of Hydrocarbon Base Oil Through Molecular Dynamics Simulations
,”
Tribol. Lett.
,
60
(
3
), pp.
1
9
.
30.
Bair
,
S.
, and
Qureshi
,
F.
,
2003
, “
The High Pressure Rheology of Polymer-Oil Solutions
,”
Tribol. Int.
,
36
(
8
), pp.
637
645
.
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