SUPER•ADDITIVE PACKAGES:
The Next Generation of Lubrication
Performance Enhancing Additives
Ajay P. Malshea*, Wenyang Zhang~’, Melanie Murphya, and Greg Schwartz”
a

nGlide Division, NanoMech, Inc., 2447 Technology Way, Springdale, AR 72764
b NanoMech Energy, 100 Crescent Court, Suite 440, Dallas, TX 75201

*Contactingauthor. Email: [email protected]; (Dr. Malshe is also a Distinguished Professor and
Endowed Chair Professor ofMechanical Engineering at the University ofArkansas, Fayetteville, AR)

Abstract
Traditional additive packages address critical functions
including anti-wear, anti-friction, extreme pressure,
corrosion resistance, and related others for a wide
selection of greases. The tight balance of additive
chemistries, with interplay among their chemical
compatibility as well as their synergistic response
with the mating surfaces, is critical and typically fully
exploited when building a well-balanced grease product.
However, over the decades this tight balance has become
even tighter as lubricant manufacturers are addressing
exponential demands from manufactures of mechanical
devices. Mechanical devices such as gear boxes, valves,
ball bearings, pin joints, and others are experiencing
severe demands fi~r lubrication due to harder and harder
materials ofconstruction, tighter and tighter tolerances,
extended lubricant changing interval cycles and drastic
limitations on pricing for lubrication engineering.
Among all the applications, the critical driving force
for expanding this scope of traditional lubricants is
bounda,ry lubrication, ~heje direct contact of multiple
mechanical surfaces~is driving the energy and durability
equation,
Super~additive packages are the next generation of
addfflve~ capable of working with or without, and
above and beyond the established traditional additive
packages. These super-additive packages are engineered
using fundamentals ofmaterial-genomics allowing one
to dial-in and enhance the functional performance of
selected properties, depending on the end application.
This technical report is presenting a specific case study,

especially for demonstrated performance of superadditives in fully formulated market available greases
used for various large market sectors. An atlas of such
super-additives to work alongside traditional additives is
at the heart of this new platform to be used with a wide
selection of off-the-shelf lubricant greases or customized
specialty greases.

Introduction
Globally, as population and industrialization are
growing, there is an exponential growth in the
demand for energy use. The demand for energy is
primarily driven by human activities in two types of
systems—electrical systems and dynamic mechanical
systems. Especially, growth in the population and
industrialization, and growth in mechanical devices are
almost moving in parallel. In the dynamic mechanical
devices, the driving factors for energy losses are due to
friction, material losses due to wear, the collective down
time, and the cost of maintenance. These issues have
become severe across various industry sectors. Another
key observation is that many of these energy hungry
mechanical components/systems are being rapidly
designed and redesigned for better performance with
tighter and tighter tolerances under harsher operating
conditions, and for extended lubrication maintenance
intervals.
These mechanical devices continue to face demanding
(quantitatively and qualitatively) boundary lubrication
conditions. Lubricating film, also called tribofilm, is
the last line of defense under the boundary lubrication

38 VOLUME 79, NUMBER 1

NLGI
[1 1. These triboflims results from thermodynamic
metastable conditions due to transient loading and
thermal conditions during asperity-to-asperity contact
engaging various chemistries in lubricants. Especially,
these complex lubrication chemistries and related
functions are delivered using greases and oils as media
containing state-of-the-art solid and/or liquid lubricants
and functional additives (e.g. for anti-wear, anti-friction,
extreme pressure, etc.)
Especially in most greases, manufacturers use multiple
soap matrix or inorganic thickeners carrying oil and
functional additives. Over the time, grease technology
has super-matured and been customized to achieve
intricate, tighter balance of chemistries and desired
functions. Especially, the critical properties of greases
for boundary lubrication are application specific for
coefficient of friction, wear, load carrying capacity,
oxidation/corrosion resistance, water resistance, thermal
stability, and last but not the least, for wide operating
temperatures and other environmental conditions. This
customization of greases, over the years, tailored for
specific application conditions have resulted in a range of

ci)
0
C
(U

ci)
0~

/4~.
T

4

products.
For example, one of the major and application specific
users of grease lubricants is the gas and oil sector.
Applications range from drilling to fracking, production
to transportation, and refining to end-users across the
hydrocarbon supply chain. Highly specialized steels and
metal alloys such as Inconel, with micron to submicron
tolerances and harsh operating conditions (from -70
°F to +700 °F), in on- and off-shore conditions and for
the highest desired safety are becoming common to gas
and oil components/systems. Many times it has been
noted that on one mechanical system, such as a gate
valve or a ball valve or others, more than one type of
grease lubricant needs to be applied to meet those part
specific custom conditions, occasionally resulting in
manufacturing errors. At the same time, these products
are being challenged as the gas and oil sector is adapting
to harsher exploration conditions such as the oil sands
project in Canada exposed to extreme abrasive and
cold conditions, geothermal exploration in Iceland and
Indonesia, and subsea exploration at thousands of feet
below the sea level in various parts of the world.

Performance demands on
mechanical assets:
~ Harder materials of
construction
~ Tighter
complextolerances
designs and

/~

~ Harsher operating
conditions
~ Extended period between
servicing intervals
Progress intechnology
“performance”
lubrication
can
deliver (greases and oils)

Time (service life)
Figure 1 Major discrepancy in performance expectations
39 NLGI SPOKESMAN, MARCH/APRIL 2015

NLGI~
At this time, for the energy gas and
oil boom in the US and the world,
there is a critical need for current
grease lubrication technology
to innovate and adapt rapidly to
meet these growing aggressive
new performance demands from
various mechanical systems!
sectors and bridge the application
specific functional gap (Figure 1).
Innovation in additives is one of
the most effective ways for desired
innovation and adaptation to bridge
this functional gap. In fact, the path
of innovation in additive technology
must address the Holy Grail of
the lubrication industry which is
to deliver multiple chemistries for
multiple functionalities at the tip
of every asperity in interacting
surfaces. The observed size of
these asperities, measured using
high magnification microscopes,
in boundary lubrication is
typically submicron to nanoscale.
So as to address these region
specific functional demands, it is
apparent that delivery of additives
at submicron to nanoscale is
imminent. This challenge also
presents unique opportunities
to discover nano and submicron
scale science for understanding
novel science, and applying those
discoveries to deliver new set of
engineering properties at those
length scales using multi-component
additive packages, and those
which could work seamlessly with
established current grease platform
with state-of-the-art additives and
fully formulated lubricants.
This nanoengineered multi-

component additive packages (NOT
one element or one compound),
and thus nanoengineered grease
lubricants are the new class of
advanced lubricant materials
designed using principles of
nanoscience and engineering
such as macromolecular delivery,
convergent assembly, multi-phase
translation, and directed assembly.
This timely progress proposes the
next generation of opportunities,
such as correcting friction at every
asperity, the ability to enhance
load carrying capacity by more
than 100%, delivering oxidation
resistance and corrosion resistance
without adding additional corrosion
inhibitors, super resistance to water
washout at asperity level, and the
last but not the least, the ability
to seamlessly blend with fully
formulated greases of various types
with preexisting additives, solids
and liquids. This next generation of
advanced additive packages due to
their following discussed superior
functional abilities is called “super
additive” packages from this point
onward [2-5]. This paper discusses
these opportunities, specifically with
a case study, for a gate valve used
extensively globally in the gas and
oil sector.

Engineering Problems
In this study, authors have
identified a gate valve application
for grease lubricant design,
development and testing purposes.
This application is one of the most
severe applications in gas and oil
sector. These valves experience
– 40 VOLUME 79, NUMBER 1

direct metal-to-metal contact under
high pressure, abrasive and corrosive
fracking fluids, wide temp variation,
etc. As shown in figure 2a, crosssection of a typical gate valve, and
figure 2b, surface wear on a typical
gate and a seat during operation,
where needs to address such wear
and related issues. This excessive
sliding wear is caused by (1) high
contact pressure (sometimes more
than 10,000 psi) in reciprocating
sliding motion between a gate and
a seat which leads to difficulty
of lubricant replenishment and
failure of tribofllms, (2) fluids
going through the valve removes
lubricant applied on valves and hurts
lubrication, (3) outside abrasive
contaminants from fracking sands,
muds, etc. causes excessive wear
and (4) extreme temps, e.g. low
temperature (-50 ~F lowest) in
northern region of US and Canada
negatively affects flow properties of
lubricant. An application specific
design of nanoengineered superadditive package was developed
for a traditional, fully formulated
lubricant to address the above
discussed chemo-mechanical
problems (e.g. wear and extreme
pressure protection, harsh operating
condition, and low temperature).
This specially designed lubricant
solution was intended to deliver
formation of a continuous robust
triboflim to avoid sliding weai~,
as well as survive in the severe
operating conditions.

NLGI
(a>

(b)

Severe Sliding Wear
Marks on Gate and Seat

I,

fr

1?

Figure 2: (a) Gate valve cross-sectional view [7]; (b) tested gate and seat of a gate valve which
show clear sign of abrasive wear

Experimental Procedure
A fully formulated off the shelf grease with wellbalanced additive chemistry was selected as a
benchmark, which is widely used extensively for
gate valvesin gas and oil sector, especially for arctic
conditions. Application specific nanoengineered
super-additive package was used to advance treat the
benchmark grease formulation. This processing could be
accomplished as a top-treatment as well as in the typical
grease manufacturing process.
This new grease lubricant solution was tested to analyze
tribological efficacy using industry standard analytical
tecbniques such as four-ball wear, extreme pressure
(El~, coefficient of friction, and grease penetration to
stud~Mction!wear reduction, load carrying capacity
enhaiicement, and ability to maintain grease structure.
A ser~fes of complementary grease qualification tests
including copper corrosion, corrosion preventive, water
spray-off, and reciprocating tribological testing, to
simulate actual field boundary lubrication conditions,
was performed for fully formulated benchmark grease

and super-additive additized benchmark.
Scanning electron microscopy (SEM) and energy
dispersive X-ray (EDS) techniques were used to analyze
remaining protective layer after water spray-off test and
tribo-chemical films formed in testing under boundary
lubrication conditions. Following discussion presents
details.

Material Selection
Benchmark Grease: fully formulated, commercially
available mineral oil based bentonite thickened NGLI
#1.5-2 grease (non-drop). This grease was selected
for heavy duty gate valve applications especially due
to harsh environmental conditions as well as for cost
considerations for this open-loop mechanical system,
where the grease is pumped in and out during fracking
cycles. Product data sheet of fully formulated benchmark
grease is shown in below table 1.

41 NLGI SPOKESMAN, MARCH/APRIL 2015

NLGI
Table 1: Product Data Sheet ofFully Formulated Benchmark Grease

Gate Valve Lubricant

Fully Formulated
balanced
Bentonite WellGrease

Tolerance Window

NLGI #
Thickener
Base Oil Viscosity, S.S.U., 100 °F1210
°F
Viscosity Index
Four-ball Wear Scar Diameter, mm,
ASTM_D2266
Four-ball EP Weld Load, kg, ASTM
D2596
Coefficient of Friction
Water Spray-off, Percentage Removed,
ASTM_D_4049
Copper Corrosion, ASTM D4048
Corrosion Preventive, ASTM D1743

1 5-2
Bentonite
975[70

Not provided
Not provided
Not provided

66
062

Not provided
±0[04

160 max

One loading stage

010

±001

99A0%

Less than 1%

1b
Fail

Same rating
Same rating

Super-additive Selection: In order to significantly enhance wear resistance, reduction in

friction, and load carrying capacity provided by current benchmark grease, authors have
selected traditional as well as super-additive multi-component chemistries for top-treatment
(table 2), during the screening phase of this research. Following standard grease mixing
procedures, a 6% treat rate was chosen due to the severe working conditions of the application.
Table 2: Selection of the State-of-the-art Additives and Nanoengineered Super-additive Systems for Top
Treatment ofFully Formulated Benchmark Grease

Additive Type
Fully Formulated Benchmark Grease (benchmark)
Commercial Available State-of-the-art Premium Micro
Particle Based Additives (CM3)
Commercial Available State-of-the-art Premium Micro
Particle Based Additives (CM6)
Commercial Available State-of-the-art Premi urn Additive
Package (C6)
Super-additive Package I (NSI)
Super-additive Package 2 (NS2)
Super-additive Package 3 (NS3)
Testing Program
1. Screening Tests: screening tests were performed for all
additiveformulations along with benchmark to select
best performingformulations for the following analysis
and end user application.
Grease penetration (60 strokes worked penetration)
was performed for all formulations using ASTM
D2 17 Standard Test Methods for Cone Penetration of

Treat Rate, wt
Not Applicable
3%

6%
6%
6%
6%
6%

Lubricating Grease [8].
Wear performance was identified using ASTM
D2266 Standard Test Method for Wear Preventive
Characteristics of Lubricating Grease (Four-Bail M~thod)
by measuring wear scar diameters. Coefficient offriction
was also studied and recorded during ASTM D2266 test
[9].

42 VOLUME 79, NUMBER 1

NLGI
Load carrying capacity of tested lubricants was
determined using ASTM D2596 Standard Test Method
for Measurement of Extreme-Pressure Properties of
Lubricating Grease (Four-Ball Method) [10].
Grease Qualification Tests: after screening tests, the
best performance multi-component super-additive 1
(NSJ)formulation was selectedfor grease qual~fication
testing, simulated tribological testing, and surface
morphological and chemical analysis.
As the end user application could include bronze
parts, copper corrosion was studied using ASTM D4048
Standard Test Method for Detection of Copper Corrosion
from Lubricating Grease [11].
Corrosion resistant property was evaluated using ASTM
D1743 Standard Test Method for Determining Corrosion
Preventive Properties of Lubricating Greases [12].
Water resistant properties, especially spray-off
resistance, was analyzed using ASTM D4049 Standard
TestMethod for Determining the Resistance of
Lubricating Grease to Water Spray [13].
2.

3. Application Specific Tribological Testing: application
spec~flc tribological testing was designed to simulate
boundary lubrication conditions ofgate valve.
As shown in table 3—section 1, in order to best simulate
field conditions in the lab and study friction and wear
response of nanoengineered super-additive, testing
parameters were carefully chosen for contact mechanics,
mating materials, surface finish, load, speed, temperature,
and duration of test. Per section 2, similar tribological
testing was carried out on steel coupons with grease after
water spray-off testing. The purpose of this test is to study
thin protecting layer left by multi-component superadditive after tribological testing. Bruker UMT-3 multifunctional tribometer equipped with a high temperature
linear reciprocating module was used in this study as
shown in figure 3.

Tcibl~e 3: Tribological Testing Parameters Simulating Field Application Conditions

Section 1—tribological testing on

Section 2—tribological testing on

grease samples,
NSIbenchmark and
Linear reciprocating
2000 psi and4000 psi to
simulate different loading
conditions

stainlessspray-off
steel plate,
after water
testing
Linear reciprocating

Duration

30 minutes

10 minutes

Contact

Area
0.5-0.6 pm for pin, 0.3 pm for
plate

Area
0,5-0.6 pm for pin, 0.3 pm for
plate

Relative lowto simulate
boundary lubrication (0.25 Hz,
0.5 cm/s)
Room temperature (25 ~C)
440 c stainless steel plate and

Relative low to simulate
boundary lubrication (0.25 Hz,
0.5 cm/s)
Room temperature (25 “C)

Tribological Testing
Parameters
Motion

Load

Surface Roughness
Speed
Temperature

Testing Specimens

pin

43 NLGI SPOKESMAN, MARCH/APRIL 2015

2000 psi

440 c stainless steel plate and
pin

NLGI
Figure 3: Multi-functional Tribometer with Linear Reciprocating Module

4. Morphological and ChemicalAnalysis: FEIXTNova
Nanolab 200focused ion beam/scanning electron
microscopy (FIB/SEM) and built-in energy dispersive
X-ray spectroscopy (EDS) techniques were usedfor
surface morphological and chemical analysis.
Surfaces of stainless steel plates after water sprayoff test were studied for benchmark and selected NS 1
grease forniulations using SEM and EDS to understand
morphology and chemistry of the protective additive
film. Wear tracks after tribological testing, using
coupons after water spray-off testing, were also analyzed
using SEM and EDS to study elemental composition
and morphology of tribo-chemical films formed by
lubricants. Stainless steel coupons were rinsed with
heptane following standard cleaning procedure to
remove excessive amount of lubricant left on the surface.
All te~ts~were repeated at least 3 times to establish
understanding of error range of each lubricant.

Results and Discussion
Part I. Screening Tests
To select best additive formulations, screening tests
were performed. As shown in table 4, both CM3 and
CM6 showed better friction, wear, and load carrying
capacity performance than benchmark grease. Also,
CM6 showed slightly better performance than CM3 with
addition of 3% weight more in additive concentration.
However, C6 commercially available and recommended
additive package showed negative response in wear
protection and grease consistency (softened benchmark
grease to NLGI grade #1).
For nanoengineered super-additive lubricant packages,
NS1 and NS2 showed very promising performance
enhancement in every category. At the same time,
the additized grease maintained grease consistency.
Although NS3 showed superior performance in friction,
wear, and EP (three loading stages over benchmark
grease), it did change NLGI # below 1, unlike benchmark
grease.

– 44 VOLUME 79, NUMBER 1

NLGI
Table 4: Screening Testing Results of Various Selected Formulations in Comparison to Benchmark
Grease (Note: data in parentheses is for tolerance window of reported testing results)

Sample

Benchmar

Name

k Grease

CM3

CM6

C6

NS1

NS2

NS3

NLGI#

L5-2

L5-2

L5-2

1

L5

L5-2

(15-1

ASTM
D2266
Four-ball
Wear Scar

0.62
(±0.04)

0.56

0.54

~±0.O3)

0.50
~±0.02)

0A9
~±O.05)

0.51

(±0.02)

0.69
~±0.06)

~±0.03)

0.10
(0.01)

0.09
(±0.01)

0.08
(±0.01)

0.09
(±0.02)

0.07
(±0.01)

0.06
(±0.01)

0.06
(±0.02)

160 max.

200 max.

(one
loading

(one
loading
stage)

250 (one
loading
stage)

250 (one
loading
stage)

Diameter~

nmi
Four-ball
Coefficient
of Friction
(COF)

ASTM
D2596

Four-ball
EP Weld
Load~ kg

stage)

In a conclusion of screening
tests, best performer NS1 and NS2
(highlighted in table 4) were selected
for detailed grease qualification tests
in the next step. C6 and NS3 were
eliminated from contention due
to negative performance response.
Furthermore, CM3 and CM6 were
eliminated because they did not
show comparable results with NS 1
and NS2 even under the same
dosage rate.

Part II. Grease Qualification Tests
To further evaluate key properties
such as corrosion and water
resistance as required by the end
user application, grease qualification
tests were designed and carried
out for benchmark grease and NS1

200 (one
loading

stage)

250 max.

(one

loading

stage)

and NS2 super-additives additized
benchmark formulations. As shown
in table 5 (with tolerance window)
compared with benchmark, NS1
formulated grease showed more
than 20% reduction in wear, 30%
reduction in friction, and 2 loading
stages increase in weld load. More
importantly, it is noteworthy that
NS1 also enhanced corrosion
and water resistant properties
of benchmark grease without
intentionally adding corrosion
inhibitors and polymers for water
resistance. Although there is only
2.6% improvement (table 5) in
water spray-off removal of grease
over the benchmark, a clear optical
difference was observed between
benchmark and NS1 formulated
– 45 NLGI SPOKESMAN, MARCH/APRIL 2015

315 max,
(one

loading
stage)

greases. As shown in figure 4b,
no grease was left on the stainless
steel plate for benchmark grease,
but a thin layer of network of
nanoengineered lubricant could
be clearly seen on NS1 plate after
water spray-off. This important
observation was believed to be a
result of well balanced and designed
nanoengineered super-additive
packages to form a network of
surface protecting films among nano
and sub-micron scale asperities,
which could deliver a barrier
for metallic parts from external
corrosive and humid environment.
Nanosized multi-component
chemistries were demonstrated
to form a surface protecting film
and tribo-chemical films easier

NLGI
than state-of-the-art lubricant additives along with
better surface coverage as (1) nanosized chemistries can
enter and bond with nano and submicron scale surface
asperities; (2) nanoengineered additive packages deliver
more surface area and metastable active material phases
which contribute to better surface affinity and lucid film
formation protecting almost every asperity; and (3) well
designed multi-component macromolecular chemistries
at nanoscale help efficient delivery and rapid activation of
super-additive packages [1]. Morphological and chemical
analysis of surface protecting film after water spray-off
testing is discussed in Part IV of this paper.

Authors found out that NS2 additized grease
formulation showed equally good tribological
performance over benchmark and well-maintained
corrosion and water resistant properties compared to
benchmark. For non-technical reasons, NS1 formulation
was recommended for the subsequent tribological
testing, chemical analysis of tribo-chemical films,
and field evaluation due to its superior tribological
performance and corrosion/water resistance.

Table 5: Grease Qualification Testing Results ofBenchmark Grease, NS1, and NS2 Chosen after Previous
Screening Tests (Note: data in parentheses is for tolerance window of reported testing results)
Performance
Enhancement

Lubricant and Testing
Information

Benchmark

NSI

NS2

Four-ball Wear, mm,
ASTM D2266

0.62 (±0.04)

0.50 (±0.02)

0.49 (±0.05)

Friction Coefficient

0.10 (±0.01)

0.07 (±0.01)

0.06 (±0.01)

Four-ball EP Weld Load,
kg, ASIM D2596

160 max. (one
loadinq staqe)

250 (one loading
stage)

Copper Corrosion, ASTM
D4048

lb (same rating)

250 (one loading
stage)
lb-la (2 Ia
ratings out of 6
ratings)

of NSI
24%
reduction
30%
reduction
2 loading
stages higher

lb (same rating)

Corrosion Preventive,
ASTM D1743
Water Spray-off, Percent
Removed, ASTM D 4049

Fail (same
ratinci)
99.4% (less
than 1%)

Pass (5 Pass out
of 6 ratings)

Fail (same
rating)
99.2% (less than

Pass the test

1%)

analysis

96.8% (±1.4%)

Figure 4: Pictures
ofstainless steel
plates (coated with
benchmark grease
and NSI superadditive additized
benchmark) before
(4a) and after (4b)
ASTM D4049 water
spray-off testing

– 46 VOLUME 79, NUMBER 1

See above

NLGI
Part III. Application Specific Tribological Tests
Section 1 —tribological testing on benchmark grease and
NS1 additized benchmark grease
As shown in figure 5 and table 6, testing results
obtained by simulating actual working conditions
for gate valve for gate-ring contact, NS 1 showed
significant amount of wear reduction and weight loss
(wear) reduction (up to 69% reduction) compared with
benchmark grease, especially under higher loading
condition of 4000 psi. Significant amount of sliding wear

was observed for benchmark grease with deep scratches
believed to be due to inability to withstand high-pressure
boundary lubrication conditions and inability of
traditional grease formulation to penetrate wear interface
under severe contact. Very light wear marks were
observed for NS1 additized benchmark grease. Moreover,
17% friction reduction was found for NS1 compared to
benchmark grease at 2000 psi. This observation is also
consistent with four-ball testing results.

Figure 5: Stainless Steel Testing Coupon with Circled Wear Marks after 2000 psi (5a) and
4000 psi (5b) Reciprocating Tribological Testing (see Table 3for testingparameter details)

Table 6: Friction and Wear Results ofBenchmark Grease and NS1 Additized Benchmark Grease
under Simulated Boundary Lubrication Conditionsfor Gate Valve Gate-seat Contact
2000 psi testing results

4000 psi testing results

COF

Weight Loss, nig

COF

Weight Loss, mg

Benchmark Grease

0.120 (±0.016)

1.8 (±0.5)

0.096 (±0.008)

6.5 (±1.8)

NS1 Additized
Benchmark Grease

0.102 (±0.010),
17% reduction

1.2 (±0.2), 33%
reduction

0.096 (±0.007)

2.0 (±0.6), 69%
reduction

Sample Name

Note: data in parentheses is for tolerance window of reported testing results.
– 47 NLGI SPOKESMAN, MARCH/APRIL 2015

NLGI
Section 2—tribological testing on stainless steel plate after
water spray-off testing (testing is based on grease left on the
plate)
As shown in figure 6 and table 7, NS1 formulated
benchmark grease showed significant amount of
reduction in friction and reduction in wear (e.g. weight
loss reduction up to 70%) compared with benchmark
grease. The intent of this was to study tribological
performance of surface protecting film left on stainless
steel coupon after water spray-off tests and special single
coupon was prepared with leftover films after water
spray-off from benchmark and NS 1 treated benchmark
greases. This test was carried out under boundary
lubrication conditions for load of 2000 psi and pre
defined time duration of 10 minutes (see Figure 3 for
testing parameter details). Significant amount of sliding
wear was observed for benchmark grease with deep
scratches due to inability to withstand high pressure

boundary lubrication condition. Very light wear marks
were observed for NS1 additized benchmark grease. This
observation confirmed the advanced anti-wear (AW) /
anti-friction (AF) / extreme pressure (EP) functionality
of surface protecting films formed by nano engineered
lubricants. Under harsh operating conditions, the
benchmark grease with state-of-the-art additive package
failed to protect the surface, but the same grease treated
with nanoengineered super-additives is able to form
a surface protecting film to continue to provide these
advanced functionalities. Surface morphological and
chemical analysis of tribo-chemical films formed after
reciprocating tribological testing are discussed in Part IV
of this paper.

Figure 6: Stainless Steel Testing Coupon with Circled Wear
Marks after 2000 psi Reciprocating Tribological Testing on
Specimens after Water Spray-off Testing

Table 7: Friction and Wear Results ofBenchmark Grease and NS1 under Simulated
Boundary Lubrication Conditions after Water Spray-off Testing

Sample Name
Benchmark
NS1

2000 psi testing results
COF

Weight Loss, mg

0.211 (±0.019)

4~0 (±0.8)

0.170 (±0.01 1), 19%

1.2 (±0.4), 70%

reduction

reduction

Note: data in parentheses is for tolerance window of reported testing results.
– 48 VOLUME 79, NUMBER 1

Part IV. Morphological and Chemical Analysis
Surface morphological and chemical (elemental)
evaluation was performed by SEM and EDS techniques
to better understand the mechanism of superior
performance provided by NS1. Two studies are presented
in this section: (1) study of stainless steel plate coated
with benchmark grease and NS1 additized benchmark
grease after water spray-off testing. As shown in figure 7
and 8—the purpose of this study was to physically and
chemically identify surface protecting film formed by
benchmark grease, if any left after water-spray off, and
NS1 additized benchmark grease; (2) study of tribo
chemical films on wear tracks for benchmark and NS 1
additized greases, after water spray-off testing followed
by tested reciprocating tribometer under boundary
lubrication regime, as shown in figure 9 and 10—the
purpose of this study is to understand delivery of
functional nanoengineered multicomponent additive
chemistries using NS 1 additized benchmark grease
and the mechanism for measured better tribological
performance.
IL Chemical and morphological microscopic study of
stainless steel plate coated with benchmark grease and NSJ
additized benchmark grease after water spray-off testing
As shown in figure 7 (a) and (b) SEM micrographs,
after water spray off testing, there is no benchmark grease
left on the stainless steel coupon except several bentonite
particles left on the plate as identified by Al and Si
elements as shown in figure 7 (c), elemental mapping
EDS results. Surface profile of steel substrate could be
clearly seen since there is no protective film formed by
benchmark grease. Very little or close to no amount of Al
and Si elements were found as shown in figure 7 (d) and
(e), EDS spectra and atomic ratio, which is consistent
withSElyl observation.
From figure 8 (a) and (b) SEM micrographs, clear
lubricant coating/distribution was found on stainless
steel~coupon and texture of substrate (steel surface) could
not be observed which also verified that a thin layer
of surface protecting film was formed among surface
asperities (texture) after water spray-off. Other evidence
is that the atomic ratio of Fe element is extremely low
as shown in figure 8 (e) which means the steel surface
is well covered by a film so that electrons could not

penetrate or escape from substrate for SEM analysis. In
figure 8 (c) and (d), signatures of tribo active elements
such as Mo, S, and N were found well dispersed in film!
lubricant substrate. Mo and S atomic ratio is closely
maintained at 1:2 which partly shows there is no
chemical reaction between NS1 and grease structure
after water spray-off testing. Interestingly to note that Al
and Si elemental concentration from bentonite is also
significantly higher than benchmark grease studied in
figure 7. It is believed that well dispersed nanoengineered
super-additive strengthened the network structure of
benchmark bentonite grease avoiding complete wash
out and at the same time, the strong surface affinity
of nanoengineered super-additive chemistries bond
and strengthened surface film on steel substrate. This
dispersion strengthening effect is under further study
to understand the bonding between nanoengineered
additives and grease network structure for physical
or chemical or hybrid bonding. Above microscopic
observations well reconfirm macroscopic findings of
water spray-off test with and without nano engineered
additive packages discussed and as shown in figure 4.
II. Chemical and morphological microscopic study
of tribo-chemicalfilms on wear tracksfor benchmark
and NSJ additized greases, after water spray-off testing
followed by tested reciprocating tribometer under
boundary lubrication regime
Wear tracks of benchmark grease after reciprocating
tribological testing under boundary lubrication were
studied for microscopic morphological and chemical
analysis (figure 9). Significant amount of wear debris,
sharp edges, and rough surfaces of wear tracks were
observed in figure 9 (a) and (b) which are consistent with
worse tribological performance observed during prior
testing. More importantly, based on elemental analysis
in EDS, wear tracks are dominated by Fe element and no
tribo-chemical film (protective films) traces were found.
This observation reflects that under harsh operating
boundary lubrication gate valve condition, benchmark
grease could not form tribo-chemical film to protect
the surfaces. Due to no protective film formation, steel
debris formed by direct metal-to-metal contact resulting:
(1) in scratched surface to create more steel debris; (2)
in asperity to asperity welding with surface under high

– 49 NLGI SPOKESMAN, MARCH/APRIL 2015

pressure and peeled off later to create more wear; (3) in
welding among steel debris and asperities under high
pressure to form larger and harder steel debris because
of strain hardening which could significantly damage the
surfaces. This explains wear mechanism and inability of
surface protection of benchmark grease.
In a clear comparison to results in figure 9, in figure
10 (a) and (b), wear tracks ofNSl additized grease
under the same tribological testing conditions showed
much smoother wear tracks protected by continuous
tribo-chemical film without steel debris. Tribo active
elements Mo, S. and N were predominantly observed
and found weiLdispersed in tribo-chemical films as
shown in figure 10 (c) EDS elemental mapping results.
In addition, multicomponent additive functional packets
were either absorbed~or embedded into tribofilms, ready
to deliver for tribofilni replenishment and deliver their
multi-functionalities for AW, AF, EP and anti-corrosion

1]. Interestingly, from the EDS quantification results in
figure 10 (e), atomic ratio of Mo and S is found to be less
than 1:2. This finding demonstrates chemical reaction
under severe lubrication condition. It was believed that
nanoengineered additive packages reacted with steel
substrate to form multi-layer friction-polymer based
tribo-chemical films to provide surface protection
[1, 6]. Current finding clearly explained the superior
performance of NS 1 additized benchmark grease during
tribological testing and its capability to continuously
provide lubrication under harsh environmental
conditions, such as after water spray-off testing and in an
open ioop mechanical system like a gate valve. Further
Raman and XPS analyses are in progress to obtain the
in-depth understanding of chemical compositions of
tribo-chemical films.

Figure 7: (a). SEM image at 350x magnification ofstainless steel plate coated with benchmark grease after
water spray-offtesting (b). SEM image at 2000x magn~fication; (c). Elemental mapping results ofEDS
identified elementsfor studied surface at 350x SEM image; (d). EDS spectra ofstudied surface at 350x SEM
image; (e). EDS elemental ratio calculatedfrom above EDS spectra

– 50 VOLUME 79, NUMBER 1

rb). 2000x

F~t

5I~14~HY~
&4?4~M( T5~kM

(d) EDS Elemental Analysis

LU

j,)

A
L.

El

C
0
Al
Si
Mn
F~

~

AN

~5
~
13
14
25

s~r~

urin.
[wt~

c
%]

norrn~
[wt~

C Atom.

%]

K—~ri~

24.52

23~8Q

K—r1~i~

O~7i
0.05
O~3O
0.77
76.70

O~69

E—~rie~
X—~ri.~

J~—~ri~

26 ~

(e)~EDSElementa1Ratio

0~D5

O~29
0~75
7442

[at~

C

%]

Er~oL~

Ewt~ %]

5~57
i~27

2~7

0.0~E~
O~31
0.40

Q~Q
O~O
0.0

39.40

2.3

~

O~1

(a). 350x
&ut~ce coated with NS 1

~1

~ThJ

—~

i-~

n

[wt.~]

C

~
~
7
~
C)
~
Al 13 }C—il~
~114er1~
16
ii~r~
F~26Ket~j~
42 Ll~
N

n

[‘~rt.%]

[~fz.%]

~)1~2
~.O2

~
~2O

~

1.67
~
1.1~
?i3,~~q
1,69

1.2~
~
0,93
1~3FjF~
1.22

D.6~
~
D~3~
503
0.19

E

r~ ~

1~ ~V

[wt..~]

12~7
1~5
D~1
fl~

O~1
O~1

(e)EDSEentalRatioAnalysjs ~ioo.ooioo,n~
Figure 8: (a). SEM image at 350x magnification ofstainless steel plate coated with NS1 additized
benchmark grease after water spray-off testing; (b). SEM image at2000x magnification; (c). Elemental
mapping results ofEDS identified elementsfor studied surface at 350x SEM image; (d). EDS spectra of
studied surface at 350x SEM image; (e). EDS elemental ratio calculatedfrom above EDS spectra

Rough/sharp ~ar tracks and steel debiis
(e) Elemental Mapping at 8000x

EDS Elemental Analysis

4

El AN

S~ri~s

urari.

C

[wt.%]
C
0

Mn
Fe

6
8
1~
25
26

X—~ri~s
~—~ri~
X—~r±~
X—~r±~
X—~erie~

6.58
D.65
D.25
D.72
~9.26

(eSE1eiue~ita1RatioAna1ysis

norm. C Atom. C
[wt.~]
[at. ~]
6.75

0.67
0,25

0.78
91.59

24.80
1.8.6
0.80
0.59
72.36

Error

[wt.~]
1.2
0.2
0.0

0.1
2.7

[1~,r~rjo1Dnnn

Figure 9: (a). SEM image at 2000x magn ~fi cation of wear tracks of benchmark grease located at steel
coupon (after water spray-off testing) tested by reciprocating tribometer under boundary lubrication; (b).
SEM image at 8000x magnification; (c). Elemental mapping results ofEDS identified elements for studied
surface at 8000x SEM image; (d). EDS spectra ofstudied surface at 8000x SEM image; (e). EDS elemental
ratio calculatedfrom above EDS spectra

El AN

C
N
C
r~1
i
S

~
7
3

J
14
15

~i~s

R—~erie~
~-~:ri~r
3~riE~
y_~rj~
~
::~:~iri~L

16 I’~-~~ ri~
r1~;?tji~

unn~
[~1t.

~]

[wt~C]

Atc~in~ C
[at~~]

[rt,~]

~~39
4~37
6~3E
C.
D~C~
E~74
~ ~r1
1i’~C~

~2~7

JI~.O4

1~5

(e).EDSEleiuentalRatioAnalysis

:;~7~
i~S~
1:,
u.44
i~37
~

3,53

1~
C. 1
2,23

~,19
o~i~,i~n

Figure 10: (a). SEM image at2000x magnification of wear tracks with tribo-chemicalfllms ofNSI additized
grease located at steel coupon (after water spray-off testing) tested by reciprocating tribometer under
boundary lubrication; (b). SEM image at 8000x magnification; (c). Elemental mapping results ofEDS
identified elementsfor studied surface at S000x SEM image; (d). EDS spectra ofstudied surface at 8000x
SEM image; (e). EDS elemental ratio calculatedfrom above EDS spectra

NLGI
Part V. Evaluation Benchmark and NS1 Additized
Benchmark Grease for Gate Valves (Assembledfor
Frac- Tree) Under Fracking Conditions

‘I

NS1 additized benchmark grease was recommended
for field-testing evaluation after showing excellent lab
performance in various perspectives. Benchmark grease
was also evaluated for base line control purpose. As
shown in figure 11, gate valves filled with benchmark
grease and NS1 additized benchmark grease were
assembled in two separate frac-trees and tested at the
same fracking sites under arctic conditions illustrated in
table 8. All field testing work was controlled by the end
user by well-established standard operating procedures.
After the end user specified fracking cycles at the site
were completed, both frac-trees were shipped back to
the factory for disassembly, cleaning, and further part
inspection/evaluation following standard operating
procedures.
After inspection, for both test valves filled with
benchmark grease and NS 1 additized benchmark grease
(figure 12 and 13):
• NS1 additized grease applied parts gave considerable
less surface damage (e.g. scratches, pittings, etc.) on
hard gates and seats;

• Density of scratches for NS1 additized grease applied
parts was much less;
o Severity of scratches, surface roughness Ra value was
an order of magnitude less for NS1 additized grease
lubricated valves;
• Resistance to water washout was enhanced by NS 1
additized grease. Gates and seats after disassembly
still showed a thin layer of NS 1 additized benchmark
grease, which is consistent with previous lab results;
• Gates and seats of benchmark grease could not be
reused while gates and seats tested with NS1 can still
be used again.
In summary, nanoengineered super-additive package,
NS 1 additized grease in field testing provide up to
90% reduction in wear volume and surface roughness
reduction. Cumulative effect of the above functional
advancements is that the life of parts in gate valve was
extended by 25-50%, based upon field observation.
(Disclaimer- data could partly vary from site-to-site and for
operator pattern.)

Figure 11: Testing Frac Tree composed of 7-8 gate valvesfilled with benchmark grease orNSl additized
benchmark grease; Table 8 Field testing specifications to make sure benchmark grease and NSJ additized
grease under the same testing conditions
Grease and

Valve
Names

Benchmark
Grease

Nanarugineered
Super-additive
Package (NSI)
Addithed Benchmark

Grease

Operating

and
Greasin~
Conditions

Testing
Loration

Estimated Frac
Tree Qpezating
Cycles: specified
number of total
greasing cycles:
Greased every 3
operating cycles

Estimated Frac Tree
Operating Cycles:
spedñed
number of total greasing
cycles : Greased ever~r 3
operating cycles

Same testing location and fradringjob in arctic
weather conditions

– 55 NLGI SPOKESMAN, MARCH/APRIL 2015

NLGI

Figure 12: Gate surfaces ofgate
valves tested with benchmark
grease (left picture with much
higher Ra values and wear) and
NS1 additized benchmark grease
(right picture with much lower
Ra value).

Figure 13: Seats surfaces ofgate
valves tested with benchmark
grease (left two seats with deep
scratches) and NS1 additized
benchmark grease (right two
seats with almost no wear).
D€~p scratches ~au~d by re~ipiocating ~o~on

– 56 VOLUME 79, NUMBER 1

NLGI
Conclusions and Future Directions
In summary, nanoengineered super-additive
package additized benchmark bentonite clay grease
provided advanced performance not only over fully
formulated well-balanced benchmark bentonite
clay grease, but showed the following results as
well:
Nanoengineered super-additive package 1
(NS1) showed 30% reduction in friction, 20%
reduction in wear, and 2 EP loading stages
higher in comparison to benchmark grease.
In another noteworthy finding, NS1 provided
better corrosion (without intentionally adding
corrosion inhibitors) and water resistant
properties. Although better water resistance is
not clearly reflected by numbers of traditional
ASTM 4049 testing results, consistent network
of protecting film was found on stainless steel
plate which was formed by nanoengineered
super-additive package based on evidence from
morphological and chemical analysis using SEM
and EDS techniques. This surface protecting
film network formed by nanoengineered superadditive packages is believed to be the last line
of defense in field application to effectively
protect machine surfaces.
• Meanwhile, NS1 showed even better
performance in friction and wear reduction,
up to 70% reduction in weight loss, under
application specific tribological testing to
simulate actual boundary lubrication condition.
Smoother wear track and evidence of tribo
active elements in wear tracks successfully
demonstrated nanoengineered super-additive
packages are delivered to mating surfaces to
form protective tribo-chemical films even under
harsh boundary lubrication conditions. Unlike
benchmark grease, it showed no evidence of
physical and chemical delivery of functional
additives.

• Cumulative effect of functional advancements
in AW, AF, EP, anti-corrosion, water spray-off
resistance for nanoengineered super-additive
packages was demonstrated by field testing to
provide up to 90% reduction in wear volume
and surface roughness.
• Further chemical composition analysis by
Raman and XPS techniques and surface profile
analysis by 3D surface profilometer of tribo
chemical films formed by nanoengineered
super-additive packages, low temperature
performance (low temperature penetration and
torque) of additized grease, and hydrocarbon
resistance of studied lubricants are necessary
and are in progress, and will be presented at
suitable time.
Finally, this technical report has presented
patented and patents’ pending breakthrough
developments in a new class of lubricant additive
packages (unlike nanoparticle component such as
friction modifier elements and compounds like
carbon, Mo52, W52, borates, copper, etc.), designed
and developed using principles of nanoscience
and engineering such as macromolecular deli*~c
convergent assembly, multi-phase translatic~%
and directed assembly. A new atlas of such multicomponent super-additives is being integl~~%ed
for various greases based on Li, Lix, calcium
suiphonate, bentonite, PFPE, silicone and
base chemistries. This new advancement~
current scientific and technical
and works in complementary and synergisti~
nature to already established greases and their
additive systems to meet the demands of
mechanical systems discussed in section on
Introduction.

– 57 NLGI SPOKESMAN, MARCH/APRIL 2015

NLGI

5. Verma, A., Jiang, WP., Abu Safe, H.H., Brown, WD.,

Acknowledgements
Special acknowledgements to Cameron International
Corporation staff for collaboration. Special thanks to
John Bartos, Jim Lovin, Joe Gross, Vasanth Annamalai,
Loc Hoang, Muneeb Dogar and all other related
Cameron associates for all collaboration work and field
testing support. Authors would also like to acknowledge
Arkansas Analytical Facility (AAF) and Electron Optics
Facility (EOF) for the use of SEM and EDS equipment
and Dr. Mourad Benamara for related technical
discussions.

References

pp. 673-678.
6. Hsu, S.M. and Gates, R.S., 2005, Boundary
Lubricating Films: Formation and Lubrication
Mechanism, Tribology International, 38(3), pp. 305312.
7. www.c-a-m.com
8. ASTM D217 10 (2010) Standard Test Methods
for Cone Penetration of Lubricating Grease. ASTM
International, West Conshohocken, PA.
9. ASTM D2266 01(2008) Standard Test Method for
Wear Preventive Characteristics of Lubricating Grease
(Four-Ball Method). ASTM International, West
Conshohocken, PA.
10. ASTM D2596 lOel (2010) Standard Test Method
for Measurement of Extreme-Pressure Properties
of Lubricating Grease (Four-Ball Method). ASTM
International, West Conshohocken, PA.
11. ASTM D4048 10 (2010) Standard Test Method for
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PA.
12. ASTM D1743 13 (2013) Standard Test Method
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of Lubricating Greases. ASTM International, West
Conshohocken, PA.
13. ASTM D4049 06(2011) Standard Test Method
for Determining the Resistance of Lubricating
Grease to Water Spray. ASTM International, West
Conshohocken, PA.

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Chemical Understanding of Friction Polymer Based
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Patent and Trademark Office; Filing Date: September
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20I~3)1~1~1te national and international allowed and
pendi~$~j~1ications.
1aIsb~A~,it4ultiple national and international
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E4Iemir, ~ ~ A.P., 2012, Fundamental
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and Malshe, A.P., 2008, Tribological Behavior of
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– 58 VOLUME 79, NUMBER 1