Note: Descriptions are shown in the official language in which they were submitted.
3~L~
It has been discovered and forms the basis o~ this disc_o-
sure that materials of the formula MXY3 wherein M is selected 'rom
the group consisting of Mg, V, Mn, Fe, Co, Ni, Zn, Cd, Sn, Pb and
mixtures thereof, preferably Fe, Zn and mixtures thereof, most pre-
ferably Zn, X is a pnictide selected from the group consisting of
phosphorus, arsenic, an-timony, and mixtures thereof, preferably
phosphorus, arsenic and mixtures thereof, most preferably phos-
phorus and Y is a chalcogenide selected from the group consisting
of sulfur, selenium, and mixtures thereof, most preferably sulfur
are superior lubricants exhibiting resistance to oxidation and ther-
mal degradation, low friction, excellent antiwear activity and long
effective life. Surfaces coated with these compositions resist
galling and damage due to adhesive or corrosive wear. As lubricants
they can be used either dry or in conjunction with conventional
lubricants selected from the group consisting of lubricating oils
and greases.
S. Soled and A. Wold in "Crystal Growth and Characteriza-
tion of In2/3 PS3", Mat. Res. Bull. Vol. 11, pg. 657-662, 1976,
Pergamon Press, Inc., discuss in their introduction a number of
mi~ed anion rich compounds of metal, pnictide and chalcogenides.
They report the work o~ W. Klingen, Dissertation, Universitat
Hohenheim, Germany, 1969, dealing with the crystal growth of the
compounds M PX3 (with M = Fe, Co, Ni, Zn, Mn, Cd, Sn, Hg or Pb; X =
S or Se) by means of chemical vapor -transport. They go on to indi-
cate that these materials are structurally related to the layer
compounds CdI2 and CdC12 and contain close packed sulfur layers with
every other interlayer filled with an ordered arrangement of metal
atoms and sigma-bonded phosphorus-phosphorus pairs. The metal atoms
are located in octahedral interstices and each phosphorus atom is
bonded in a distorted tetrahedron to three sulfur and one phosphorus
atom. Because of the large anion-anion interlayers that remain
empty (with a typical sulfur-sulfur interplanar distance of 3.4 A),
these compounds exhibit easy cleavage parallel to the crystal faces
and exhibit lubricity.
It was not recognized, however, that such material pos-
sesses and retains this lubrication capability under oxidizing cond-
itions at relatively high temperatures and performs satisfactorily
over periods of time which greatly exceed the operational times of
conventional lubricants such as MoS2.
In SLE Transactions, 14, 62, (1970) by Jamison and
Cosgrove, the lubricating characterlstics of a number of layered
transition metal disulfides and diselenides were measured. The
coefficient of friction was determined using a ball on flat type
test apparatus loaded to 250g force. The static wear member was a
3/~ inch steel sphere. The lubricants were hand burnished onto a
brass disc which acted as the dynamic wear member.
For the layered transition metal compounds which were
stu2ied, three types of lubricating behavior were observed~ Some
materials did not form adherent films; others did form films but
could not su~port a sliding load; yet others formed films which
could support heavy sliding loads. This clearly demonstrates that
not all layered materials and more particularly not all layered
sulfiaes are effective as solid lubricants.
3 _
~9~
1 ~ubrlca~:ion urlder a v~rlety of conditions, i.e.
2 oxidizing~ reducing and inert a~mosph~e a~ temperatures up
3 to abou~ 450CC, preferably from about 3lOC ~o about 450~,
4 more preferably f~^om abou~ ~00C to abou~ 450C, mos~ prefer-
ably from about 21C to about 45~C~ can be ~chieved by util~-
6 zing materials of ~he ormul.a ~XY39 whe~ein M is selected fi~
7 the g~oup consisting of Mg9 V, ~n~ Fe~ Co, Ni, Zn, Cd, Sn,
8 Pb and di and poly mi~ures thereo, preferably Fe~.~n and
9 mixtures thereo~, mos~ preferably ~n, X is a pnictide se
o lerted from ~he group consisting of ph osphor u S9
ll arsenic, anti.mony, a n d m ix tllr e 5 ~hereof, pre~erably
12 phosphorus, arsenlc and mixtures t~ reof, most preferably
phosphorus, and Y is a chalcog~nide selected from ~he group
consisting o sulur, selenium and miæ~ures thereof7 mos~
15 preerably sulfur.
16 B~ using such materials, wear ean be grea~ly
17 reduced since the lubr~cant resis~s brea~down due to .a~mos-
18 phe~e and tempera~ure conditlons particularly oxidation and
19 hlgh-temperature decompos;tion Consequently, these
20 materials are super~or lubrican~cs to those known ln
21 ~he art such as MoS~ which deteriora~e in oxidl~ing atmos-
22 pheres at relatlvel~ low temperatures. Materials which thus
23 de~erlorate ultimately permit high ~ric~ion and damage to
Z4 thé surfaces they were meant ~o protee~, the damage being
2S recogn~zed as increased wear; galling, abrasion, ~coring,
~26 coxrosion, etc.
27 The mat~rials MXY39 ~herein M~ X and Y are as
~8 previously defined1 which f~mc~ion as lubricants are prepared
by any number o~ n~e~llods kno~n in the ar~. For example9 ~he
lubricating materials can be pre~lared by the direc~ reac~ion
31 o the el~ments in e~acua~ed sealed silica tube re~ult:ing
.. ~
~7 3~ ~ ;
1 in the ~o~mation ol polycrys~alline materials.
2 Materlals of th~ fo~mula 1~XY3 w'nerein M, X and
3 are as previously de~ined~ exhibit remarkable stability a~
4,temperatures up to 450C9 preferably 400-450~C, more preferably
3lO-450C~ most p.eferably 2l-450C9 under a variety of condi-
6 tions rangi.ng from reducing to inert to oxidizing~ preferably
7 oxidizing. It is ~he .s~ability of the materials at elevated
8 temperatures under oxidiæing conditions and high load which
g makes them outs~an ding lubricants.
~he ma~erlals useful in ~he instant i~v2ntion May
11 be of ~hç general formula M.~Y3 w'nerein Mg X a~d Y are as
12 previously de~ined. Fur~her~ they may be di- or poly mixed
i3 catioQ or anion sol~d solu~ions~ ~ha~ is, the material may
14 lnclude more ~han one metal and/or more khan o11e chalcoge~
nide, ~or ex~ple
i~ Zr~ eqPS3 O ~ q C 1
17. FePSe3WZSZ O ~ Z ~ 3
18 ZQ1 q~eqPSe3~ZSZ O -- q ~ 1
19 t) ~ ~ ~ 3
Such m~xed metal and/or mix~ed chalcoge~li.de ma~erials are
21 inc~uded within the scope of the invention~ In general, pre~
22 ferred materials are ZnPS3, FeP.S3, and PbPS3.
23 The M~3 materials can ~e added to lubricating
2L~ greases in any num~er of ways. Direct addition (suspension)
2~ of finely divided ~Y3 is one alternative, while another is
26 the susperLsion in lubricating ~ils o ~3 ma~cerials which
27 ha~e b en reduced ~c~ a fine particle size by chemlca~ or
28 mechanical means. Briefly, this last mentioned tec~miqu~ in-
~9 volves di~,persing the M~Y3 material in a suitable medla such
30 as a small volume o natural or syn~het:ic oils to which has
31 been preerably added a small amcunt of a surface aCti~Je
_ 5 ~
1 dispersing agent. Th-tS iS therl added to the lub~ica~ing oil
2 as an additive in suspe~sion. T~e ~rease or lubricant l~e-ria
3 resulting from the additiorl of the ~Y3 ~ype material contains
~ from .1% ~o 20 ~t. % MXY3 ~ype material~ preferably 1~5 ~. %,
the balance ~eing lubri~atillg oil or grease.
6 Included are greases wherein lubricating oil is thick-
7 e.ned with salts~ soapsg soap-sal~ or mixecl salt complexes,
8 p~1ymeric thickeners (e.g~ polymers o~ C2 to C4 monoolefins of
g 10,000 to 200,000 Staudinger molecular weigh~ such as polyeth-3-
lo lene) and inorganic ~hickeners (e.g. clay, carbon black, silica
11 gel, e~c.) However, the method of ~he ln~en~ion is o parti-
12 cular value in cases w~ere the grease is thickened with a me~al
13 soap other ~han sodlum, and particularly where ~he metal is
14 polyvalent~ viz., an al~lline earth metal such as c~lcium, or
15 aluminum-
16 Generally~ the greases will comprise a major amount of
17 ei~her a synthetic or natural lubrica~ing oil, thickened wi~h
18 about 3 to ~9 wt. percent~ usually 20 to 4S wt. percent, of
19 a ~hickener. In the case of soap-salt and mixed-salt thick-
20 eners, ~he thickener is usually onned byco-neu~raliæation in
21 oil, by metal base, while heating ~o dehydrate or remove
22 alcohol (if an alcoholate is used in the me~al base~ of various
28 mixtures of high molecular weigh~ carboxylic acids, e.g. ~atty
2~ acids and/or inte~mediate molecular weight carboxylic acids,
25 eOg. atty or aromatic acids, with low molecular weigh~
26 carboxylic~ e.g. atty acids.
27 The high molecular weigh~ carhoxylic acids useful
28 ~or o~ming soap, soap-salt and mîxed salt thickeners include
29 na~urally occurring or syn~hetic su~skituted and unsubstitu~ed
3~ saturated and unsaturated, mixed or unmixed fatty acids hav-
31 in~ about 14 to 30, e.g., 16 to 22, carbon ~toms per m~lecule.
32 Examples of such acld~ include stearic, hydro~y s~caric, such
~ ~ ~ 7 ~ ~
1 a~ 12~h~d oxy stear.,c, dihyd.roxy stearic, po~yhydroxy stearic
2 a~d other saturated hydrox~ fatty acid~, arachidic, oleic~
3 ricinole;.c, hydrogenat2d fish oil, tallow acids, etc
~ Intermediate molecular ~eight carbo~Jlic fatty
5 acids include those aliphatic, aromatic7 alkaryl7 etc.,
6 saturated, ~msubstitu~ed monocarboxyiic acids containing 7
7 to 12 carbcn atoJns per molecule9 e.g.~ capric~ lauric, capry-
8 lic, nonanoic, benzoic acid3 etc.
9 Low molecular weight fatty acids include saturated
lo and unsatura~ced9 substitll~ed and unsu~s~itu~ed, aliphati~
11 carboxylic acids having about 1 ~o 6 carbon atoms. These
12 acids include at~y acids such as fo~nic9 acetic, propionic,
3 e~c. Ace~ic acid or its anhydride is preferred.
14 Metal bases which are.frequently used to neutralize
15 ~he above acids are the hydroxides, oxides, carbonates or
16 alcoholates o alkali metals (e~g. li~hi~n.and sodi~n~ or of
17 alkaiine earth me~als ~e.g.9 calciumj magnesium? strontium
8 and barium) or other polyvalent me~als commonly used in
19 grease making~ e.g. aluminum.
Yarious o~her additives may also be added ~o ~he
21 lubrica~ing c~nposi~lon ~e.g. 0,1 to 10.0 wt. percent based
22 on the ~otal weigh~ of the composi~ion~ for example, oxida-
23 tion lnhibi~ors such as phenyl-alpha-naph~hylamine; tackiness
24 agents ~uch as polyisobutylene; st.abilizers such as aluminum
25 hydroxy stearate; and the like.
26 The lubricatin~ oil employed as such or to produce lub-
27 r~cating grease compositlons ;.n the method of ~his invention
28 may be conventlonal natural oils as well as syn~hetic
29 lubricating oils, although the mineral lubricating oils are
30 pree~red, The synthe~.ic oils include synthet:ic~ lubricating
31 oils having a viscosity o~ at: leas~ 30 SSU at lOO~F. such as
32 ~ ers o~ monobasic acids (e,~. es~er of C~ Oxo alcohol ~it~h
.. 7 ~
~7
1 C8 Oxo acid3 ester o C13 Oxo alrohol wi'ch octanoi~ acid, etc
2 es~ers of ~ibasic acids (e g d;-2 ech~l hexyl sebaca~e, di-
3 no~yl adipate, etc.) esters of glycols (e.g. C13 O{o acid
4 diester o te~raethylene glycol, e~c.) complex esters (e g.
5 ~he complex es~er formed by reacting 1 mole of sebacic acid
6 with 2 moles of tetrae~llylene glycol and 2 moles of 2-ethyl
7 hexanoic acicl, comp1ex ester ~ormed by reac~ing 1 mole o tetra-
8 ~thylene glycol with 2 moles of sebacic acid and 2 moles o~ 2-
9~ethylhexanol, complex ester ~ormed by reacting together 1 mole
o of azelaic acid, 1 mole of tetraethyl~ne ~lycol, 1 mole of C~
Oxo alcohol7 and 1 mole of C8 Oxo acid), es~ers o phosphoric
12 acid (e.g., the ester formed by contacting 3 moles of the mono-
13~me~hyl ether of ethylene glycol with 1 mol~ of phosphorus
oxychloride3 e~c ) 5 halocarbon oils (e.g. the polyme~ of
~chlorotrifluoroethylene containing 12 recurring units of chloro-
6~trifluoroethylene~7 alkyl silica~es (e.g. methyl polysiloxanes9
17lle~hyl polysiloxanes, methyl phenyl polysiloxanes, e~hyl phenyl
siloxanes~ etc.), sulfite esters (e.g. e~ter formed by
14 ~eacting 1 mole of sulfur ~xych~oride wlth 2 moles of the
20lmethyl ether of ethylene glycol, etc.), carbonates (e.~. tne
2llcarbonate fo~ned by reacting C8 Oxo alcohol with e~hyl carbo~
22jnate to form a half es~er and reactlng-this half ester with
23lte~raethylene glycol), me~captals (e.g , the mercap~al formed
24 by reac~ing 2-ethyl hexyl mercap~an wi~h formaldehyde~9
25 ~o~nals (e.g., the formal ~ormed by reac~ing C13 Oxo alcohol
26 with f~nmaldehyde~, polyglycol ~ype syn~hetic oils (e.g~ the
27 compounds formed ~y condensing butyl alcohol with ~ units of
28 propylene oxide, etc.), or m;xtu~es of any o~ the a~ove ln
29 any p~oportions. Quite generally the mineral ~ s~lthetic
~ oils should have a viscosity wi~hin ~he range of about 35 ~o
31 200 SSU at 210F and ~ash points of about 350 to 600~ F
32 Lu~ricating olls havlng a viscosi~y lndex of 100 or hi~her
may be employed.
In the attached drawings:
Figure I shows a thermogravimetric trace for the
oxidation of ZnPS3 and MoS2;
Figure II is a schematic view of a ball on cyliner
testing device;
Figure III is a graph showing test results using
"realistic" conditions;
Figure IV, IVA & IVB reproduces the surface profiles
for several tests using a surface profilometer; and
Figure V shows test results obtained using a journal
bearing test device.
- TEST DATA
Typical MXY3 compositions were studied under differing
conditions so as to define the limits of their applicability.
They were subjected to high temperatures under inert,
oxidizing and reducing atmosphere and the point of deteri-
oration (T min) was determined from thermal gravimetric
experiments. X-ray analysis was used to identify the end
product.
A. Thermal Decomposition
ZnPS3 1000C~ Xo(-Zn5 + Y~ -ZnS + 1/4 P4S~ + 1/4 S~
(X + Y = 1) Tmin, = 450C
3 1000c FeS ~ 1/4 P4S7 ~ 1/4 S~
Tmin = 590 C
9 _
~9~3~
B. Oxidation
3ZnPS3 + 31/2 2 1000C ~-zn3(po4)2 2 2 5
T i = 450C
FePS3 + 52 1000C FePO4 + 3S2
T - 490 C
min. ~
MoS2 + 7/2 2 ) 3 2
Tmin. 310 C
C. Reduction
3 / 2 700C XO(-ZnS + Y~ -ZnS + 3H2S + PH
~ ' .
(x + y = 1) T . = 450C
mln .
3 7/2H2 1000C FeS + 3H2S~ + PH3
. 20 T i = 540C
.
_ 9~ _
~1~3~'^f3'1F~
1 F~g1lre ~ or.Js th~ ~hermogravimGtric trace for t~e
2 o~.idation o~ 7~nP53 and MoS2. Repor~s in ~he li~erature
3 shcw a si~lificant increase in ~he co~icien~ o~ friction
4 ~or MoS2 a~ high ~e~mperatures which correla~es ~ith ~he on-
5 set of oxida~lonO The increased stabili~y of ZnPS3 ~Tmin
6 C~..50C) and FePS3 (Tm~ - 4~ C) relative to MoS2 (Tmin=3lO~C)
7 under ~his realistî~ ~o~idizing) condition demons~rates their
8 superiority as a lubrican~ in real life situations.
9 In addi~iorl ~o the chemical s~abili~y o~ the MPS3
10 phases at eleva~ed temperatures9 their compatib~lity with
11 other che~icals has also been tes~edO Thege ma~erials are
12 stable to dissolution in E~2O9 ~S29 and hydrocarbons such as
pen~ane, heptane~ cyclohexane, ben~ene9 ~ylene and toluene.
In addi~ion9 other organics such as methanQl, e~hanol, di-
15 ethyl ether~ acetone and trichlorome~hane nei~her reac~ wi~h
16 nor dissolve ZnPS3 or FePS3. However9 ZnPS3 and FePS3
17 react wi~h strong aci.ds and bases (i,e. HCl9 HNO3~ CH3COOH,
8 KOH9 NaOH). The MPS3 phases also react with Lewis bases
19 such as a~non;.a and pyridine.
20 The s~ability of ~he MP53 phases in solven~s~ par- -
21 ticularly hydrocarbons, is an importan~ feature necessary
22 ~or the synthesis o~ lubricating oil and ~rease dispersions
~3 and goes ~o enhan~e the des~rability of ~hese MXY~ compounds
~4 as additive~.
~5 Tes~s o ZnPS3 a~ a dry lubrican~ under various
26 conditions (atmosphere lnert or oxidizing and dry or moist;
27 slid~ng ~pe~d-5 to 50 cm~sec; and load ioo MPa to 750 MPa
28 Hertz Stress) have been conducted usin~ the ball-on-cylinder
29 deviee,
~ . Fig~re II is a schematic o~ ~he ball on.cylinder
31 device which consis~s bas1cal.ly o a s~ationary ball which
3~ ~s loaded onto a ro~a~ing cylinder-. A dead weight load is
_ 1.0
. .
1~9731~ -
1 applied to the end o~ a lever syst~m which in turn loads
2 the ball (5?100 s~eel 9 ~C 20 to 22) onto the cylinder
3 (52100 steel~ Rc 60 to 62) with a cal~ ~ble initial Hertz~
4 ian Stress, Through th~ use of a variable speed motor, the
5 cylinder can be rotated to obtain various sliding velocities,
6 The test device is equipped with a transducer ~or recording
7 ~he frictional force. ~dditional flexibility is available
8 by enclosing the device in a gas tight enclosure which
9 allsws various blanketing abmospheres ~o be inves~iga~ed,
10 The test lubrican~ was burnished onto a precleaned (50%
11 xylene/50 methanol) cylinder from a degreased lint-free
2 cloth which ~Jas loaded with excess material, The cloth
13 containing the lubricant was pressed onto the cylinder
14 under specified condi~ions of load rota~ion speed and time
(200 g force9 200 RPMs and 15 min,~. In this way repro-
16 ducible film s co uld be achieved,
17 Figure III shows ~ypical resul~s obtained using
jB "realistic" condi~ions (moist air, 50 cm/sec sliding speed
19 and 500 MPa l~e~tz S~ress)~ The initial low fric~ion re~
corded or the nonlubricated case can be attributed to the
21 existence o an oxide surace film, The rapid increase
and eventual ailure corresponds to a progressive removal
o~ the surface oxide. Optical inves~igat~on o~ ~he wear
surace a~er failure wi~h no solid lubricant reveals a
everely galled area conflrming an adhe~ve ~ w~r mechanism.
The all of~ o the coeficien~ o friction for both MoS2
27 ~nd ~nPS3 in the ini~ial portion of the ~es~ is similar to
28 that observed o~ other lamell ar solid lubricants . This
29 "induction" or "run-inl' period can be a~tributed to an
alignment of the crystallites on the wear surface. It ~s
31 clear rom this data that the friction reduction obtained
~3~ ~sing MoS2 îs be~ter than that ~ound ~ur ZnPS3. How~v~r,
- 1~973~
1 the efect~ve lifetime o~ ~he MoS2 film is significantly
2 less than that observed for ZnPS3 burnishing.
3 In addition ~o recording ~he frictional characLer
4 and ef~ec~ive life9 an assessm~nt of the wear damage can be
made using a surface p~ofllometerO Figure IV reprodu~es
6 the surace profiles for several tests. From cylinders
7 burnished wi~h ZnPS3 and run in ~he presence of a base oil
8 (Solvent 150~ ~ a signilcant reduction in wear can be no~ed
9 relative to ~he base oil case~ (Figure IVa). In addition9
comparison of wear traeks for areas burnished with ZnPS3 and
11 MoS~ respec~ively, w~lloh we~e terminated before failure9
12 also rev~als a signiiean~ reduc~ion in wear (Figure IVb).
13 Op~ical ex~nina~-on o ~he wear tracks genera~ed for ZnPS3
14 and MoS2 bu~nished areas confirm reduced wearO The MoS2
lubricated ~rack is severely galled and pi~ted. The ZnPS3
6 track is smooth and shows l~ttle or no evidence o galling.
17 In addltion to the ball on cylinder tests, the
18 ~ore common four ball test was also made. For these tests,
19 the precleaned 52100 ~eel balls were burnished by rolling
in excess ~olid lubrican~ or 1 hour a~ 20 revolu~ions per
21 minu~e An evalua~ion of the wear was made by optically
22 measu~ing ~he wear scar diameter (WSD) genera~ed on the
23 ~hree s~ationar~ ba~s-
24 Table I records ~he da~a for the cases of no
, . .
lubricant7 ~nd for MoS2 and ZnPS3 trea~s. For bo~h MoS2
26 ~nd ZnPS3 a reduetion in wear rela~ive ~o an unlubrica~ed
21 case can be noted. For the lubrica~ed tests9 the presence
28 of an oxidizing a~mosphere degrades the antiwear activity.
29 A signi~ican~ increase in wear is observed in going from
30 iner~ to oxidizing a~mosphere for MoS2 treats. Similar
3I behavior is observed'for the ZnPS3 burnished areas~ however,
32 the ~ncrease in wear is much less ~han that found or MoS~
- 12
7 3
l ~rea~ed ballsO
2 ~gure V shows the results obtained using the
3 journal bear.ing test deviceO The application of ZnPS3~ by
4 burnishing on a runin journal9 resul~ed in reduc~ion of
~he riction coefficient~ The initial coeficient dropped
6 by 20% and ~hen slowly increased over a period of 25 days,
7 This particular ~est was conduc~ed in ~he presence of and in
8 con~unc~ion with a base oil and confi~med the initial wor~
9 done on the ball-on-cylinder device which showed a similar
reduction o~ ~riction and ncreased anti-wear ac~ivity.
' ' ~ ' ' .
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l EYAMP~E I
2 4g of ZnPS3, FePS3 and MoS2 were added respective-
3 ly to 9Gg of an aluminum complex soap-salt grease made from
4 the following components:
90 g Animal Fa~ty Acid
6 30 g Benzoic Acid
7 50 g Kolat:e (aluminum alcoholate, isopropyl)
8 1742 g Coray ~0/50 (unextracted naph~henic
9 mineral lu~ricating oil)
6 g UOP '~25 ~commercial anti-oxidant)
ll The greasc was prepared by heating the mixture of acids and
12 alcoholate in the oil, w~th the removal of alcGhol, to form
13 ~he complex of the alumlnum with the fatty acid and benzoic
l4 ~cid, and adding the anti-oxidant. The test materials, i.e.
t5 the ZnPS3, FePS3, and MoS2 were mixed respectively lnto the
~6 grease components at room temperature and the resulting formu-
17 lations were milled so as to mix the solid component uniform1y
18 in the grease. In addition, two standard extreme pressure form~
19 ulations, base grease ~ 2% Elco 114 (zinc dialkyl dithiophosphat~
and base grease ~ 3% ~ric31cium phosphate ~ 1% sulfurized poly-
21 butene were ormulated and milled. Each grease formulation was
22 subsequentl~ tested for extreme pressure properties follo~ing
23 the reapproved 1974 ASTM procedure for "Measurement of Extreme-
24 pressure properties of lubricating greases (Four Ball Method)"
(Designation D 2596-69). For the base grease and for each
~6 formula';ion the wear scar diameter (mm) was measured as a
27 function of the applied load (l~g). The last non-seizure
28 load and the weld point were recorded and the standard loa~
29 wear index was calculated. Table Il shows the results for
these tests.
,
* Trade Marks
- 15 -
~7~8
l ThRT~ r. r
2 RESULTS O~ FOUR ~ALL EXTR~ PRESSUR~
T~STS (AS~M D 259G-6~
3 Load
Sample Descrlption ~lear Index
5 Base Grease ~0
6 Base Grease ~ 2~/o Elco 114 25
7 Base Grease ~ 3% Trtcalci~phosphate 33
8 1% Sulfuri~ed polybu~ene
9 Base Grease ~ 4% MoS~ 37
o Base Grease ~ 4a/O FePS3 39
ll Base Grease ~- 4% ZnPS3 44
12 From ~his data we see tha~ addi~ion o~ ZnPS3 or FePS3
13 to an aluminum complex soap grease ilr.pro~es the extreme
14 pressure characteristics relative to the base grease
lS and also ~;th respect to standard ex~treme prcssure formu-
16 lations. In addition the perfonnance of the grease ~ith
17 4% ZnPS3 or FePS3 is superior to that found or a grease
18 fo~mula~ed with an cquivalent amount of the well-kno~m
19 solicl lubrican~ MoS2,
.
X~MPlE Il
21 ZnPS3 was added,4%, 2C/o and 1% by weigh~,to an
22 aluminum complex soap grease prepared~as in Example I.
23 The resulting grease ormulations were milled ~o disperse
24 the so~id metal pbosphorous trisulfide thrvu~hout the grease
matrix. Each o these ormulations along with the base grease
26 were evaIuated using the standard hSTM D ~596-69 and ASTM D
.
- ~ 27 2509-73 tes~ procedures. The lozd wear index and the Timken
28 pass desi.~nation given in Table III show the effectiveness of
29 ZnPS3 as an extreme pressure additive even ~I)en this material
is present as a la/o ~y weight acldit~ve. These greases were not
: ~ ~ 31 compounded witll finely divided particulates and are thlls very
32 crude test combinations.
s * Trade Mark
- 16
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7~
j TAP~7,E IIX
2 RESULTS OF EXTREI~E PRESSURE TEST FOP~ AN AL~.~INI~
COMPLEX SOAP GR ~SE-ZnPS~ GREASE FOR~ULATI~ S
3 Load Wear Tlmken
Sample Desi~nat~on _ Index (Pass.lFail3
5 ~ase Grease 25.6 Not Tested
6 Base Grease -t 4% ZnPS3 47.6 . Pass
7 Base Grease ~ 2% ZnPS3 43.8 Fail
8 Base Grease ~ 1% ZnPS3 34.3 Pass
EXAMPLE III
ZnPS3 was hand burnished on~o a 1.5 ~h di~meter
ll steel cylinder (AISI 52100 Rc ~ 20 to 22). The cylinder
12 was plaeed on a shat which allowed it to rota~e creating
13 a 50 cmlsec tangential velocity relative to a fixed 1/2 inch
14 diameter steel ball (AISI 52100 Rc ~ 60 t~ 62) (see Figure
II). The cylinder ro~a~ed in an oil (solvent 150 N mineral
16 oil) ~illed trough which constantly wet its surface with a
17 ~ilm o oil. The coeficient of dynamic friction between
18 the cylinder and the ball was recorded or the 30~nute duxa~ '~
19 tion of the tests. No signi~ican~ variation in the dynamic
fric~ional coefficient (~D ranged from 0.10 to 0.12~ was
21 noted ~or the ~es~ run on the burnished area rela~ive to
22 the unburnished portion of the cylinder. ~owever~ a subse-
23 quent investigation o ~he wQar s~ar profiles, Figure IV,
24 using a profilometer, showed a dramatic reduc~ion in wear
for the ~s~ run on the burnished area rel~tive to ~he un~
26 burnlshed area.
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