Greases are widely used for variety of applications at extreme pressures, temperatures, and speeds with obligation of high bearing and shaft life with low noise. The present study deals with the development of nanocomposite greases and records their flow and frictional characteristics. The commercial grease is modified, by dispersing nanoparticles, to get the nanocomposite greases. Reduced graphene oxide (rGO), calcium carbonate (CaCO3), and alpha-alumina (α-Al2O3) are used as nano-additives. The microstructure of newly developed greases is examined using high-resolution transmission electron microscopy (HRTEM), and the presence of different chemical functional groups is explored using Fourier transform infrared spectroscopy (FTIR). Further, the new greases are investigated for rheological, consistency, and tribological behavior using Visco Tester, penetrometer, and elastohydrodynamic (EHD) rig, respectively. The flow properties reveal the shear-thinning, yielding, and thixotropic nature of lubricating greases. The study shows that there is an optimality in concentration of different nano-additives above which grease's flow and tribological performance degrades. Up to 35%, 27%, and 10% reduction in coefficient of friction is recorded for optimum concentration of rGO nanosheets, CaCO3, and α-Al2O3 nanoparticles, respectively. The difference in the performance of nanocomposite greases can be attributed to the appearance of different friction mechanisms for different nano-additives.

References

1.
Bartz
,
W. J.
,
1978
, “
Tribology, Lubricants and Lubrication Engineering—A Review
,”
Wear
,
49
(
1
), pp.
1
18
.
2.
Torbacke
,
M.
,
Rudolphi
,
A. K.
, and
Kassfeldt
,
E.
,
2014
,
Lubricants: Introduction to Properties and Performance
,
Wiley
, Chichester, UK.
3.
Scott, P. W., and Root, J. C.,
1996
,
Lubricating Grease Guide
, 4th ed.,
National Lubricating Grease Institute
,
Kansas City, MO
.
4.
Jones
,
E. F.
,
1968
, “
The Manufacture and Properties of Lubricating Greases
,”
Tribology
,
1
(
4
), pp.
209
213
.
5.
Lugt
,
P. M.
,
2009
, “
A Review on Grease Lubrication in Rolling Bearings
,”
Tribol. Trans.
,
52
(
4
), pp.
470
480
.
6.
Salomonsson
,
L.
,
Stang
,
G.
, and
Zhmud
,
B.
,
2007
, “
Oil/Thickener Interactions and Rheology of Lubricating Greases
,”
Tribol. Trans.
,
50
(
3
), pp.
302
309
.
7.
Gonçalves
,
D.
,
Graça
,
B.
,
Campos
,
A. V.
,
Seabra
,
J.
,
Leckner
,
J.
, and
Westbroek
,
R.
,
2015
, “
Formulation, Rheology and Thermal Ageing of Polymer Greases—Part I: Influence of the Thickener Content
,”
Tribol. Int.
,
87
, pp.
160
170
.
8.
Bauer
,
W. H.
,
Finkelstein
,
A. P.
, and
Wiberley
,
S. E.
,
1960
, “
Flow Properties of Lithium Stearate-Oil Model Greases as Functions of Soap Concentration and Temperature
,”
Tribol. Trans.
,
3
(2), pp.
215
224
.
9.
Delgado
,
M. A.
,
Franco
,
J. M.
,
Kuhn
,
C. V. E.
, and
Gallegos
,
C.
,
2009
, “
Transient Shear Flow of Model Lithium Lubricating Greases
,”
Mech. Time-Depend. Mater.
,
13
(
1
), pp.
63
80
.
10.
Kuhn
,
E.
,
1998
, “
Investigations Into the Degradation of the Structure of Lubricating Greases
,”
Tribol. Trans.
,
41
(
2
), pp.
247
250
.
11.
Li
,
B.
,
Wang
,
X.
,
Liu
,
W.
, and
Xue
,
Q.
,
2006
, “
Tribochemistry and Antiwear Mechanism of Organic-Inorganic Nanoparticles as Lubricant Additives
,”
Tribol. Lett.
,
22
(
1
), pp.
79
84
.
12.
Zhang
,
Z.
,
Yu
,
L.
,
Liu
,
W.
, and
Song
,
Z.
,
2010
, “
Surface Modification of Ceria Nanoparticles and Their Chemical Mechanical Polishing Behavior on Glass Substrate
,”
Appl. Surf. Sci.
,
256
(
12
), pp.
3856
3861
.
13.
Liu
,
G.
,
Li
,
X.
,
Qin
,
B.
,
Xing
,
D.
,
Guo
,
Y.
, and
Fan
,
R.
,
2004
, “
Investigation of the Mending Effect and Mechanism of Copper Nano-Particles on a Tribologically Stressed Surface
,”
Tribol. Lett.
,
17
(
4
), pp.
961
966
.
14.
Dai
,
W.
,
Kheireddin
,
B.
,
Gao
,
H.
, and
Liang
,
H.
,
2016
, “
Roles of Nanoparticles in Oil Lubrication
,”
Tribol. Int.
,
102
, pp.
88
98
.
15.
Zhou
,
J.
,
Yang
,
J.
,
Zhang
,
Z.
,
Liu
,
W.
, and
Xue
,
Q.
,
1999
, “
Study on the Structure and Tribological Properties of Surface-Modified Cu Nanoparticles
,”
Mater. Res. Bull.
,
34
(
9
), pp.
1361
1367
.
16.
Martin
,
J. M.
, and
Ohmae
,
N.
,
2008
,
Nanolubricants
, Vol.
13
,
Wiley
, Chichester, UK.
17.
Wan
,
Q.
,
Jin
,
Y.
, and
Sun
,
P.
,
2014
, “
Rheological and Tribological Behaviour of Lubricating Oils Containing Platelet MoS2 Nanoparticles
,”
J. Nanopart. Res.
,
16
, pp.
1
9
.
18.
Hernandez Battez
,
A.
,
Gonzalez
,
R.
,
Viesca
,
J. L.
,
Fernandez
,
J. E.
,
Machado
,
A.
,
Chou
,
R.
, and
Riba
,
J.
,
2008
, “
CuO, ZrO2 and ZnO Nanoparticles as Antiwear Additive in Oil Lubricants
,”
Wear
,
265
(3--4), pp.
422
428
.
19.
Caixiang
,
G. U.
,
Qingzhu
,
L. I.
,
Zhuoming
,
G. U.
, and
Guangyao
,
Z. H. U.
,
2008
, “
Study on Application of CeO2 and CaCO3 Nanoparticles in Lubricating Oils
,”
J. Rare Earths
,
26
(2), pp.
163
167
.
20.
Dong
,
J. X.
, and
Hu
,
Z. S.
,
1998
, “
A Study of the Anti-Wear and Friction-Reducing Properties of the Lubricant Additive, Nanometer Zinc Borate
,”
Tribol. Int.
,
31
(
5
), pp.
219
223
.
21.
Yu
,
H. L.
,
Xu
,
Y.
,
Shi
,
P. J.
,
Xu
,
B. S.
,
Wang
,
X. L.
, and
Liu
,
Q.
,
2008
, “
Tribological Properties and Lubricating Mechanisms of Cu Nanoparticles in Lubricant
,”
Trans. Nonferrous Met. Soc. China (Engl. Ed.)
,
18
(
3
), pp.
636
641
.
22.
Xue
,
Q.
,
Liu
,
W.
, and
Zhang
,
Z.
,
1997
, “
Friction and Wear Properties of a Surface-Modified TiO2 Nanoparticle as an Additive in Liquid Paraffin
,”
Wear
,
213
(1--2), pp.
29
32
.
23.
Zhou
,
J.
,
Wu
,
Z.
,
Zhang
,
Z.
,
Liu
,
W.
, and
Xue
,
Q.
,
2000
, “
Tribological Behavior and Lubricating Mechanism of Cu Nanoparticles in Oil
,”
Tribol. Lett.
,
8
(
4
), pp.
213
218
.
24.
Kang
,
X.
,
Wang
,
B.
,
Zhu
,
L.
, and
Zhu
,
H.
,
2008
, “
Synthesis and Tribological Property Study of Oleic Acid-Modified Copper Sulfide Nanoparticles
,”
Wear
,
265
(1--2), pp.
150
154
.
25.
Qiu
,
S.
,
Zhou
,
Z.
,
Dong
,
J.
, and
Chen
,
G.
,
2001
, “
Preparation of Ni Nanoparticles and Evaluation of Their Tribological Performance as Potential Additives in Oils
,”
ASME J. Tribol.
,
123
(
3
), pp.
441
443
.
26.
Mohamed
,
A.
,
Osman
,
T. A.
,
Khattab
,
A.
, and
Zaki
,
M.
,
2015
, “
Tribological Behavior of Carbon Nanotubes as an Additive on Lithium Grease
,”
ASME J. Tribol.
,
137
(1), p. 011801.
27.
Zhao
,
G.
,
Zhao
,
Q.
,
Li
,
W.
,
Wang
,
X.
, and
Liu
,
W.
,
2014
, “
Tribological Properties of Nano-Calcium Borate as Lithium Grease Additive
,”
Lubr. Sci.
,
26
(
1
), pp.
43
53
.
28.
Wang
,
L.
,
Wang
,
B.
,
Wang
,
X.
, and
Liu
,
W.
,
2007
, “
Tribological Investigation of CaF2 Nanocrystals as Grease Additives
,”
Tribol. Int.
,
40
(
7
), pp.
1179
1185
.
29.
Ji
,
X.
,
Chen
,
Y.
,
Zhao
,
G.
,
Wang
,
X.
, and
Liu
,
W.
,
2011
, “
Tribological Properties of CaCO3 Nanoparticles as an Additive in Lithium Grease
,”
Tribol. Lett.
,
41
(
1
), pp.
113
119
.
30.
Cheng
,
Z. L.
, and
Qin
,
X. X.
,
2014
, “
Study on Friction Performance of Graphene-Based Semi-Solid Grease
,”
Chin. Chem. Lett.
,
25
(
9
), pp.
1305
1307
.
31.
Ge
,
X.
,
Xia
,
Y.
, and
Cao
,
Z.
,
2015
, “
Tribological Properties and Insulation Effect of Nanometer TiO2 and Nanometer SiO2 as Additives in Grease
,”
Tribol. Int.
,
92
, pp.
454
461
.
32.
Mungse
,
H. P.
, and
Khatri
,
O. P.
,
2014
, “
Chemically Functionalized Reduced Graphene Oxide as a Novel Material for Reduction of Friction and Wear
,”
J. Phys. Chem. C
,
118
(
26
), pp.
14394
14402
.
33.
Lee
,
C.
,
Li
,
Q.
,
Kalb
,
W.
,
Liu
,
X.-Z.
,
Berger
,
H.
,
Carpick
,
R. W.
, and
Hone
,
J.
,
2010
, “
Frictional Characteristics of Atomically Thin Sheets.
,”
Science
,
328
(
5974
), pp.
76
80
.
34.
Choudhary
,
S.
,
Mungse
,
H. P.
, and
Khatri
,
O. P.
,
2012
, “
Dispersion of Alkylated Graphene in Organic Solvents and Its Potential for Lubrication Applications
,”
J. Mater. Chem.
,
22
(
39
), pp.
21032
21039
.
35.
Berman
,
D.
,
Deshmukh
,
S. A.
,
Sankaranarayanan
,
S. K. R. S.
,
Erdemir
,
A.
, and
Sumant
,
A. V.
,
2014
, “
Extraordinary Macroscale Wear Resistance of One Atom Thick Graphene Layer
,”
Adv. Funct. Mater.
,
24
(
42
), pp.
6640
6646
.
36.
Nasrollahzadeh
,
M.
,
Babaei
,
F.
,
Fakhri
,
P.
, and
Jaleh
,
B.
,
2015
, “
Synthesis, Characterization, Structural, Optical Properties and Catalytic Activity of Reduced Graphene Oxide/Copper Nanocomposites
,”
RSC Adv.
,
5
(
14
), pp.
10782
10789
.
37.
Jin
,
D.
, and
Yue
,
L.
,
2008
, “
Tribological Properties Study of Spherical Calcium Carbonate Composite as Lubricant Additive
,”
Mater. Lett.
,
62
(10–11), pp.
1565
1568
.
38.
Zhang
,
M.
,
Wang
,
X.
,
Fu
,
X.
, and
Xia
,
Y.
,
2009
, “
Performance and Anti-Wear Mechanism of CaCO3 Nanoparticles as a Green Additive in Poly-Alpha-Olefin
,”
Tribol. Int.
,
42
(
7
), pp.
1029
1039
.
39.
Narayan
,
J.
,
2011
, “
Lubricant Having Nanoparticles and Microparticles to Enhance Fuel Efficiency, and a Laser Synthesis Method to Create Dispersed Nanoparticles
,”
U.S. Patent No. 7,994,105 B2
.
40.
Radice
,
S.
, and
Mischler
,
S.
,
2006
, “
Effect of Electrochemical and Mechanical Parameters on the Lubrication Behaviour of Al2O3 Nanoparticles in Aqueous Suspensions
,”
Wear
,
261
(
9
), pp.
1032
1041
.
41.
Jiao
,
D.
,
Zheng
,
S.
,
Wang
,
Y.
,
Guan
,
R.
, and
Cao
,
B.
,
2011
, “
The Tribology Properties of Alumina/Silica Composite Nanoparticles as Lubricant Additives
,”
Appl. Surf. Sci.
,
257
(
13
), pp.
5720
5725
.
42.
Peña-Parás
,
L.
,
Taha-Tijerina
,
J.
,
Garza
,
L.
,
Maldonado-Cortés
,
D.
,
Michalczewski
,
R.
, and
Lapray
,
C.
,
2015
, “
Effect of CuO and Al2O3 Nanoparticle Additives on the Tribological Behavior of Fully Formulated Oils
,”
Wear
,
332–333
, pp.
1256
1261
.
43.
Coates
,
J.
,
2000
, “
Interpretation of Infrared Spectra, A Practical Approach
,”
Encyclopedia of Analytical Chemistry
, Wiley, Hoboken, NJ, pp.
1
23
.
44.
Vagenas
,
N. V.
,
Gatsouli
,
A.
, and
Kontoyannis
,
C. G.
,
2003
, “
Quantitative Analysis of Synthetic Calcium Carbonate Polymorphs Using FT-IR Spectroscopy
,”
Talanta
,
59
(
4
), pp.
831
836
.
45.
Lee
,
J.-A.
,
Kim
,
M.
,
Kim
,
H.-M.
,
Lee
,
J. K.
,
Jeong
,
J.
,
Kim
,
Y.-R.
,
Oh
,
J. M.
, and
Choi
,
S. J.
,
2015
, “
The Fate of Calcium Carbonate Nanoparticles Administered by Oral Route: Absorption and Their Interaction With Biological Matrices
,”
Int. J. Nanomed.
,
10
, pp.
2273
2293
.
46.
Soleimani
,
S.
,
Salabat
,
A.
, and
Tabor
,
R. F.
,
2014
, “
Effect of Surfactant Type on Platinum Nanoparticle Size of Composite Pt/a-Al2O3 Catalysts Synthesized by a Microemulsion Method
,”
J. Colloid Interface Sci.
,
426
, pp.
287
292
.
47.
Bartz
,
W. J.
,
1971
, “
Solid Lubricant Additives—Effect of Concentration and Other Additives on Anti-Wear Performance
,”
Wear
,
17
, pp.
421
432
.
48.
Mas
,
R.
, and
Magnin
,
A.
,
1997
, “
Experimental Validation of Steady Shear and Dynamic Viscosity Relation for Yield Stress Fluids
,”
Rheol. Acta
,
36
(
1
), pp.
49
55
.
49.
Palacios
,
J. M.
, and
Palacios
,
M. P.
,
1984
, “
Rheological Properties of Greases in EHD Contacts
,”
Tribol. Int.
,
17
(
3
), pp.
167
171
.
50.
Yeong
,
S. K.
,
Luckham
,
P. F.
, and
Tadros
,
T. F.
,
2004
, “
Steady Flow and Viscoelastic Properties of Lubricating Grease Containing Various Thickener Concentrations
,”
J. Colloid Interface Sci.
,
274
(
1
), pp.
285
293
.
51.
Katyal
,
P.
, and
Kumar
,
P.
,
2012
, “
Central Film Thickness Formula for Shear Thinning Lubricants in EHL Point Contacts Under Pure Rolling
,”
Tribol. Int.
,
48
, pp.
113
121
.
52.
Jang
,
J. Y.
,
Khonsari
,
M. M.
, and
Bair
,
S.
,
2007
, “
On the Elastohydrodynamic Analysis of Shear-Thinning Fluids
,”
Proc. R. Soc.
,
463
(
2088
), pp.
3271
3290
.
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