Note: Descriptions are shown in the official language in which they were submitted.
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PATENT
Case 890936
MFT~OD OF WARM FORMING AND EXTRUSION OF METAL
AND MFTAL WORRI~G COMPOSITION5 ~S~ UL T~ER~IN
Ed~ard J. Gudowicz
Lawrence R. Cohen
~c~ground of be Invention
~15 The~present inventlon generally reIates to
the warm forming and extrusion of metals and to
improvements in compositions that can advantageously
be used in these me~al working operations. More
particularly, this invention is directed to the warm
forming and extrusion of metals at temperatures above
about 1,100 F. In this regard, an important aspect
of the present invention is directed to the use of
rare~earth metal halides, such as cerium or~lanthanum
trifluoride,~in compositions used in the~warm forming
~;25 ~ and extrusion of steel. ~ ` ~
Warm forming and ext~rusion of metal are
procéss~es~generally involving applying a metal
working, lubricant composition~;to the~surface~of the
metal~prior~to the~deformation ther~e~of. As~such,
these composi~ions need to meet~a~variety of
requl~rements.~ For exampl~e, i~n addl~tion to
lubrication performance,~they must provide protection
of~the~metal~surface~from abrasion~and like damage.
Furthermore, they~should be~relatively easy to apply
and remove as well as compatible with subse~uently
applied coating materials.
Many of these metal~worklng lubricant
~; compositions are homogeneous blends ~ormulated for a
specific applica~ion wher~ certain properties are
favored over others~but which necessarily are a
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compromise between conflicting requirements.
Heterogeneous metal working lubricants, such as for
example dispersions of lubricant substances in water
or other volatile medium are also known. Such
heterogeneous lubricants are intended, upon
application to a metal workpiece and evaporation of
the volatile medium, to leave a continuous
homogeneous lubricant film on the metal workpiece.
~o achieve a balance of properties
compositions useful in the warm forming of metal,
these compositions generally employ a range of oils,
waxes, soaps and occasionally polymeric materials,
each of which has advantages for specific
applications. For example, U.S. Patent No. 4,687,587
to Daglish et al. discloses a lubricant for metal
forming comprising discrete particles of a waxy
material having a softening point above the
metal-forming temperatures in a solid or viscous
monomeric organic carrier. Similarly, U~S. Patent
No. 3,873,458 to Parkinson discloses a process for
cold forming or shaping metal having a resin-oil
coating prepared ~rom a dispersion of a copolymer of
ethylene and acrylic acid in a lubricant oil.
Correspondingly, U.S. Patent No. 3,167,511 to
Crawford et al. discloses the use o chlorinated
polypropylene in a lubricating oil as a lubricant for
broaching, cutting and rolling metal. These and
other lubricants known in the art, however, fail to
~ provide the needed lubrication and surface protection
to a metal workplace during the forming or extrusion
thereof at temperatures above about 1,100 F.
A precoating is often applied to the me~al
before the application of the lubricant. This
precoating can contain, for example, lime, zinc
phosphate and/or soaps. The use of such a precoating
procedure, however, also fails to permit the warm
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forming and extrusion of metal at the high tempera-
tures desired for the forming and extrusion of
numerous metal parts, particularly those made from
hard metals.
It has been known for some time that rare
earth trifluorides such as lanthanum trifluoride and
cerium trifluoride are useful as solid lubricants.
See Rare Earth Fluorides and Oxides--An Exploratory
Study of Their Use as Solid Lubricants at
Temperatures to 1,800 F. (1,000) C. NASA TND-5301,
1969). Similarly, U.S. Patent No. 4,507,214 to
Aldorf discloses the use of rare earth metal halides
in a lubricating grease to form a lubricating
composition to lubricate wheel bearings. U.S. Patent
No. 4,715,972 to Pacholke likewise describes the use
of cerium fluoride as one of several solid lubricant
particle additives for gear oil. Correspondingly,
U.S. Patent No. 3,830,280 to Larsen discloses the use
of rare earth halide such as cerium trifluoride or
lanthanum trifluoride as lubricants for die casting
components. None of these prior art disclosures,
however, contains any suggestion of a liquid metal
working lubricant composition which is suitable for
the warm forming and extrusion of metals at
temperatures above about 1,100 F.
It is; therefore an object of this
invention to provide a method for the warm formirlg
and extrusion of metals at high temperatures,
particularly a'c temperatures above about l,lon F.
Another object of this invention is to
provide an improved composition useful for the warm
forming and extrusion of metals especially at high
temperatures.
Another object of the present invention is
~o provide a metal working lubricant composition
which is stable and does not decompose at elevated
temperatures above about l,100F.
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Another objec~ of this invention is to
provide a metal working composition which exhibits
improved lubricating characteristics during metal
forming and extrusion at high temperatures and also
protects the surface of the metal workpiece from
corrosion and abrasion.
Another object of the present invention is
to provide a composition for the warm forming and
extrusion of metals which, in addition to providing
the lubrication during the forming and extrusion,
continues to provide lubrication after the cooling of
the metal.
Another object of the present invention is
to provide a high temperature, metal working,
lubricant composition that can readily be removed
from the metal workpiece after it has been removed
from the form.
Other objects of the present invention will
become apparent from the ensuing description:
Su-mary of the In~ention
The present inqention is directed to
improvements in methods for warm forming and
extrusion of metals, and to compositions useful
thereinO These improvements permit the performance
of those metal workiny operations at temperatures of
up to about 1,800 F and higher.
In accordance with an important aspect of
the present invention, the methods and compositions
thereof which are especially useful in warm forming
and extruding metal involve the use of a rare earth
metal halide in such compositions~ These
compositions are liquids having a viscosity less than
about 1,500 S.U.S. at 100 F. and include a liquid
base, viscosity enhancer increasing the viscosity of
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the composition to between about 150 and about 1,500
S.U.S. at 100 F.; a lubricant effective at elevated
temperatures of at least about 400 F., and a rare
earth metal halide. Optional components include
graphite and/or molybdenum disulfide.
Deta ed Description of _he Present Invention
In the process of warm forming metall
liquid lubricant is generally applied to the metal by
fl~ooding, dipping, brushing or spraying on the part,
preferably on a continuous process with the overflow
being collected and returned to a central reservoir
; for recirculation. Consequently lt is required that
~he lubricant composition be a liquid. In order that
it be abl~ to provide the necessary lubrication it
should have a viscosity at 100 F. of between about
150 and about 1~500 S.U.S. Liquid compositions of
this viscosity can be pumped and~at the same time
furnish the ne ded lubricity. Following;application
of the liquid lubricant deformation of th metal
workpieve takes place followed~ by removal of the
lubricant from the formed product. Often the metal
;
workpiece has a precoating which can contain lime,
zinc phosphate~and/or soaps.
It has now been found that the
incorporation~of rare earh metal halides into the
lubrlcant compositlon lDcteases~the~t~emperature at
which metal forming can be effected to about
1,800 F. and higher. This is~a sign1ficant~increase
from prior methods which have an upper limit of
effective performance of about 1,100 F. Thus, the
present process can be performed at~temperatures
~ between about 300 F. and 1~,800 F. For many
; applications, the process is performed at
temperatures between about 900 P. and 1,500 F.
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Likewise in the extrusion of metal, liquid
lubricant is applied so that a lubricant film is
present between the extruded billet and the die. As
with warm forming, the viscosity of this liquid
composition should be between about 150 and about
1,500 S.~.S. at 100 F.
The presence of a rare earth metal halide
in the lubricant composition raises the temperature
at which extrusions can be effected in an efficient
manner to about 1,800 F. and higher. Prior
compositions do not afford the necessary lubrication
and metal protection properties at these high
temperatures.
Since the methods of warm forming and
extrusion of metal allow for the use of temperatures
of up to about 1,800 F. and higher, they are
particularly valuable in applications using the
ferrous metals e.g. steel as well as other metals
such as, for example, copper, bronze, brass and
aluminum. These methods can be performed at
temperatures between about 300 F. and 1,800 F. For
the forming and extrusion of many objects, however,
temperatures between about 900 F. and 1,500 F. aré
generally employed.
Various liquid compositions can be used to
perform the present methods.
One such composition is an oil based
composition. A particularly useful oil-based
composition comprises the following components:
3~0 1) liquid base
2) viscosity enhancer to increase the
viscosity of the composition to between
150 and 1~500 S.U.S. at 100 F.
3) lubricant effective at elevated
temperatures of at least about 400 F.
4) rare earth metal halide.
Among optional components of the lubricant
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composition of this invention are graphite and
molybdenum disulfide.
The amount of the li~uid base component in
the composition will vary with the specific method
being performed and the metal being warm formed or
extruded. In general this component constitutes from
about 40 to about 90 weight percent of the
composition.
Various animal oils, vegetable oils, fats,
~10 fatty esters and mixtures thereof can be used as the
liquid base in the present lubricant compositions.
Since this non-petroleum derived material constitutes
an important portion of the composition, its
`~ selection will necessarily materially effect the
physical characteristics of the composition, such as
its viscosity and adherence to the metal workpiece.
It is pre~erred that the base be a fat,
e.g. a triglyceride. Since triglycerides are made by
esterifying the three hydroxy groups of glycerin with
fatty acids, often the triglycerides will contain
unreacted fatty acids. Fatty acids are in general
straight-chain compounds, containing from about 8 to
about 18 carbon atoms. A;particularly useful
triglyceride, prime burning lard oil, is about 99.5
weight percent trigl~ycerides or related compounds and
less than 0~5 weight percent fatty acids. Another
useful base is soybean oil having lubricating
viscosities from 50~S.U.~S. ~o about 1,000 S.U.S. a~
100 F. Also useful are oleic acid, sul~urize~ lard
~30 oil, marine oil trlglyceride, rape seed oil~ tall oil
and paraffin oil.
Since the purpose of the viscosity enhancer
is to have a liquid composition with a viscosity of
from about 150 to about 1,000 S.U.S. at 100 F., a
variety of materials that will increase viscosity of
a liquid can be used. A particularly useful
viscosity enhancer is aspha1tic material. In
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addition to increasing the viscosity of the liquid
base, it also improves the adhesion of the
composition and imparts lubricity. In general the
viscosity enhancer should be present in an amount of
from about 2 to about 25 weight percent of the
composition. Other viscosity enhancers that can be
used in the present composition are polybutene,
aluminum stearate and degras.
Numerous lubricants can be used as the low
temperature lubricant composition of the present
composition so long as they provide efficient
lubrication at a temperature of at least about
400 F. and preferably from about 400 F. to about
1,100 F. A particular class of lubricants of value
in the present compositions are sulfur-containing
compounds. These lubricants are well known in the
art and provide good lubrication properties at
temperatures up to about 1,100 F. Sulfurized
mineral oil and sulfurized fatty oil are useful for
this compo~ent. Examples of other such materials are
sulfurized fat, mineralized sulfur, sulfurized
hydrocarbons, sulfurized caster oil, sulfurized and
- chlorinated oil, and the like.
In general, the sulfurized compound can be
present in an amount of from about 5 to about 50
weight percent of the lubricant~composition; however,
for most purposes this amount will be between about
10 and about 20 weight percent.
In accordance with an important aspect of
the present invention, the metal working lubricant
composition includes a rare earth metal halide,
preferably fluoride. While other halides such as the
chloride are known, available and useful, the
fluorides are more preferred. In particular the rare
earth trifluorides such as lanthanum trifluoride and
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cerium trifluoride are preferred. Normally these rare
earth metal halides are present in amounts of up to
from about 2 to about 30 weight percent or hi~her of
the composition with an amount of from about 5 to 10
percent being generally desired. The particle size
of the rare earth metal fluoride should be relatively
ine.
In addition other solid lubricants can also
be included in the present composition as optional
components. These solid lubricants which include
molybdenum disulfide and graphite can each be present
in amounts up to about 10 weight percent of the
composition. Their presence can improve the overall
lubricity of the composition.
Other optional lubricants that can be
included in the present compositions include mica,
calcium carbonate and zinc stearate.
The molybdenum disulfide, other optional
solid lubricants and the rare earth metal halide can
be incorporated as finely divided powders having a
particle size for example, from about 0.01 microns to
about 100 microns, preferably from about 0.1 to about
45 microns. This invention, however, is not limited
to any specific particle size component.
The composition of this invention can be
prepared by standard procedures known to the art. In
gener~al they can be prepared by mixing the in~redients
at a slightly elevated temperature. In order to make a
uniform mixture, the rare earth metal trifluoride
should be added slowly with mixing. Sufficient
mixing, about an hour, should be per~ormed so as to
obtain a uniform composition. As an alternative
procedure, the composition of the present invention
can be prepared by milIing its components.
In addition to oil based compositions, it
is often desirable to have available a water-based
composition, which can be lower in cost and toxicity.
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Such compositions are composed of the same components
as the oil-based compositions; i.e. liquid base,
viscosi~y enhancer, lower temperature lubricant
effective at temperatures of at least about 400 F.
and rare earth metal halide.
Thus while many of the operative components of the
water-based compositions are identical to the
components in the oil-based compositions, there are
certain distinctions.
As with the oil-based compositions, the
aqueous compositions ùtilize a viscosity enhancer.
Generally, this can be any material that increases
the viscosity of the composition to between about 150
and 1,500 S.U.S. at 100 F. and is water compatible.
15~ useful materials include cellulose compounds such as
sodium carboxymethyl cellulose, glycols, such as
diethylene glycol, propylene glycol and butylene
glycol, and certain specialized waxes, such as
Carbowax 3350.
Since it is more difficult to obtain a
uniform mixture in water than in oil, usually there
should also be present in the composit~ion wetting
agents and dispersants. As is general with
water-based compositions containing solid components,
the wetting agents and dispersants assist in retaining
- particles in dispersion so that the compo ition will
be uniform. Numerou~s dispersants and wetting agents
are known in~the art.
Optional components in an aqueous
composition of the present in~ention include
defoamers,anti-microbial agents and corrosion
~ inhibitors. These components can~perform useful
; ~ functions in the present compositions.
Since it is~uneconomical to ship water,
rather than prepare compositions containing water, it
is often desirable to prepare a concentrate that is
shipped to the site of the warm forming or extrusion
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operation as a concentrate and then dilute it with
water to a composition usable in the method for warm
forming or extruding metal. In preparing a
concentrate that can be diluted to an aqueous
composition, a glycol such as diethylene glycol,
propylene glycol or butylene glycol may be used in
the composition as the viscosity enhancer.
It has been found that the heretofore
described lubricant compositions provide excellent
lubrication in the warm forming and extrusion of
metals at temperatures in excess of 1,100 F. The
composition is stable at temperatures higher than
1,100 F. and is stable at 1,800 F. or higher.
Furthermore, the composition protects the metal from
corrosion and abrasion and can be easily applied and
; removed by conventional means.
In its application for warm forming and
extrusion of metal, the present composition is
applied to the metal by conventional methods such as
dipping, flooding, brushing or spraying. For best
results it is preferred~that the viscosity of the
composition be between about 500 and 1,000 S.U.S. at
100 F. This permits reaay~application of the
lubricant composition to the metal. Among the metals
for which the present composition may be used~are
steel, copper, bronze, brass, aluminum and the like.
other metals may also be used in the present method
for warm~forming which comprisez applying de~ormation
pressure to metal which has been coated with the
present composition. This method is especially
applicable to metals being formed at temperatures up
to and in excess of 1,100 F. and up to about
1,800 F. and higher.
Also the composition of the present
invention can be used in the extrusion of metals. In
this method, metal, including those previously
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described as being applicable for metal forming are
coated with the present composition and extruded at
temperatures up to about 1,800 F. and higher. The
composition of the present invention provides
excellent lubrication and protection of the metal
from corrosion and abrasion.
EXAMPLE 1
The improved high temperature performance
of the metal working composition and method of the
present invention was demonstrated by comparing the
performance of a commercially available metal working
lubrlcant ~EXTRUDOIL 519HT), a chemically identical
commercial ~etal working lubricant which also
includes molybdenum disulfide (EXTRUDOIL 519HT-MOS),
and a metal working composition chemically identical
to the EXTRUDOIL 519HT-MOS which also included
c~rium trifluoride. Both thQ EXTRUDOIL 519HT and
EXTRUDOIL 519HT-MOS are available from Witco
Corporation, Allied-Relite Div1sion.
The EXTRUDOIL 519HT product is composed of
~1 Lard Oil (a prime burning lard containing 99.5
weight percent glyceride~derivatives and less than
0.5 weight percent free fatty acids), an asphaltic
25~ viscosity enhancer, and a lubricant~constituent made
up of a ulfurized fatty oil and a sulfur-cont~aining
mineral oil. The EXTRUDOIL 519HT MOS contains the
same ingredients as EXTRUDOIL 519HT in the same
relative amounts and, in addition includes 10
percent, by weight, of a molybdenum disulfide
dispersion. The metal working lub~icant product
embodying the present invention contained the same
ingredients as the EXTRUDOIL 519HT ln the same
relative amounts and, in addition, included 5
percent, by weight, each of a molybdenum disulfide
dispersion and cerium trifluoride.
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Each of these metal working lubricants was
tested during the extrusion of 15/16 inch diameter
1050 steel wire to form cam shaft lobes with a
National Machinery Model 1000 extruder having a
carbide die. The die was flooded with the lubricant
which was continuously recirculated and the
extrusion temperatures incrementally raised while
observing the performance of the lubricant.
The EXTRUDOIL 519HT metal working lubricant
which did not contain molybdenum disulfide or a rar~
earth metal halide worked well within the temperature
;~ range of 800-900 F. Increasing the temperature
beyond 900 F. decomposed the composition and at
` ~ these higher temperatures there was insufficient
lubrication to form the lobe.
The EXTRUDOIL 519HT-MOS metal working
lubricant containing molybdenum disulfide but not
containing a rare earth halide permitted formation of
the lobe at temperatures between about 1,000 F. and
~0 1,100 F. Increasing the temperature beyond
1,100~F. decomposed the composition and caused
insufficient lubrication to form the lobe.
The metal working lubricant which contained
cerium trifluoride permitted formation of the lobes
at temperatures of 1,500 F. and above without any
observable breakdown of the metal working lubricant.
Thus the present compositions can be u~sed
effectively at temperatures no~ readily lubricated by
prior petroleum-based compositions. This permits the
ready formation of warm molded and extruded parts
efficiently at temperatures of about l,500 F. and
higher.
The following examples are illustrative of
other compositions which are within the scope of the
present invention. Examples 2-9 describe oil based
compositions; Examples 10-13 describe aqueous
compositions of the present invention; and Examples
14 and 15 describe concentrates which are readily
dispersible in water.
ComPonent ~ ht Percent
#1 Lard Oil 54
Asphaltic Type Material 14
Sul-Perm 18* 11
Mineralized Oil 6
Containing Sulfur
Molydenum Disulfide 5
Dispersion
Graphite 5
Cerium Trifluoride 5
: 20 *Sul-Perm 18 is a sulfurized fatty oil having
a viscosity at 100 F. of approximately 2,800
S.U.S. to 3,300 S.U.S.; a flash point of
450 F.; a fire point of 490 F.; a weight of
: 8.4 pounds per gallon; and containing 17
:25 weight percent sulfur.
: Example 3
Component Weight Percent :
~1 Lard OiI 40
~ Asphaltic Type Material 8
: Sulfurized/Chlor~nated Oil 29
: Molydenum Disulfide :12
Dispersion
Lanthanum Trifluoride11
Exampl e 4
Component Weiqht Percent
Marine Oil 56
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Example 4 (CONT.)
Coml~onentWeight Percent
Asphaltic Type Material 15
Sulfuri2ed Caster Oil 19
Graphite 5
Cerium Trifluoride 5
Example 5
ComponentWei~ht Percent
Soybean Oil 70
: ~ Aluminum Stearate 4
Sulfurized Fat 12
Mineraliæed Oil 10
; 1~5 ~ Containing Sulfur
Zinc Stearate 2
~ : Ceri~m Trifluoride 2
: ~ Example 6
ComponentWeiqht Percent
Soybean Oil 65
Degras : 4
Sulfurized Sperm Oil 12
; Mica 5
: :25 : Cerium Trifluoride: 14
~ ~ Exampl e ?
: Component :Weiqht Percent
~ Rape~Seed Oil ~ 60 ~:
: 30 : Polybutene 2Q
: Pearsall 0~ 319* 10
Lanthanum Trifluoride 10
~ *Pearsall OA 319 is a synthetic sulfurized
: 35 sperm oil replacement containing about 17~.8
weight percent sulfur having a viscosity of
270 S.U.S. at 210 F. and~3tOOO, S.U.S~ at
100 F. and~weighing 8.6 pounds per gallon.
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Example 8
Component Weiqht Percent
Tall Oil 58
Asphalt 5
Pearsall OA 319 15
Base 380* 5
Graphite 3
Lanthanum Trifluoride 14
*Base 330 is a sulfurized hydrocarbon having a
: sulfur content of 38 weight percent, weighing
9.2 pounds per gallon, having a viscosity at
100 F. of 420 S.~.S. and 60 at 210 F.
15 : ExamPle 9
Component ~ Weiqht Percent
Sulfurized Lard Oil ~ 65
Asphaltic Type Material 15
Di-tert-nonyl Polysulfide 6
Pearsall OA 377* 5
Calcium Carbonate 3
; Cerium Trifluoride 6
: *Pearsall OA 377 is a sulfurized olefinic
25 : hydrocarbon:containing typically 36 weight
percent sulfur and having a viscosity at~51
S.U.S. at 210 F. ~and 245 S.U.S. at 1:00 F.
and weighing 8.5:8: pounds per gallon. It is
completely soluble in naphthinic and
paraffinic oils and has a flash point of
335 F~ and a fire point of:360 F.
~: : Exam~le 10
Component Weig~
Water 40
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xam~ e _ 0 (CONT. L
mponent Weiqht Percent
Diethylene Glycol
Carboxymethyl Cellulose 0.5
Sodium Hydroxide (50~) 5
Adipic Acid 5
Molybdenum Disulfide 18.5
Dispersion
Cerium Trifluoride 30
ExamPle ll
_omponent Weiqht Percent
Water 60
Diethylene Glycol 2
Carboxymethyl Cellulose
Sodium Hydroxide 15
Adipic Acid 10
Molybdenum Disulfide 5
Dispersion
Cerium Trifluoride 7
Example 12
: Component Wei~ht Percent
: 25 ~ : Water 40
Diethylene Glycol 5
Borax ~ l :
Tripolyphosphate 20
N-lO (surfactant)
30 : Carboxymethyl Cellulose
Molybdenum Disulfide 7
: Disparsion
Cerium Trifluoride 2S
:: :
Example 13
_o~ponent Weiqht Percent
Water 60
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Example 13 tCONT.)
Component Weiqht Percent
Diethylene Glycol lO
Borax 2
Tripolyphosphate lO
N-10 tsurfactant)
Carboxymethyl Cellulose 5
Molybdenum Disulfide 6
Dispersion
Cerium Trifluoride 6
: Exam~le 14
Component Weight Percent
Borax 38
Dispersant
Carboxymethyl Cellulose
Adipic Acid 5
Sodium Hydroxide Granules 5
Graphite 30
Molybdenum Disulfide lO
: ~ Dispersion
Cerium Trifluoride 10
: Exa~ple 15
25:: : Component Weight Percent
Borax 30
Dispersant 0.5
Carboxymethyl Cellulose 0.5
: Adipic Acid 10
Sodium Hydroxide Granules 5
: ~ Molybdenum Disulfide 10
: Dispersion
Graphite 19
: Cerium Trifluoride 25
~35
It will be understood that the above-
described embodiments of the present invention are
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merely illustrative of the present invention and that
modifications thereto may be made by those skilled in
the art without departing from the sp.irit and scope
thereof.
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