Note: Descriptions are shown in the official language in which they were submitted.
WO93/03919 PCT/US92/07062
2Q9~3~ 1
--1--
DE8CRIPTION
8~FAC~ FD~I8HES AND
METHODS FOR ~E P~ODUCTION T~ER~OF
TE~HNICAL FIELD
'
This invention relates to surface finishes which
impart nonabradable and nonetchable, dllrable dry r
lubricity, corrosion resistance and improved wet film
entrapment characteristics to a substrate and to methods
for applying such surface ~inishes to a substrate.
Although this invention is primarily directed to the
s~rface finishing of metallic substrates, it should be
`` noted that it is likewise applicable to surface finishes
for application to other suitable substrate materials such
as ceramic compositions. Furthermore, it should be noted
that the metallic ~ubstrates employed herein may range
-~ from very hard metals having a hardness factor measured on
; the RockwPll C scale of greater than 40 to soft metals
having hardness values measured on the RocXwell B scale.
Accordingly, a diversity of substrate materials may be
utilized in this invention provided that the material has
sufficient structural integrity to withstand the high
pressure impact application techniques employed herein.
A wide variety of corrosion-resistant coatings as well
as methods for the application of such coatings to
substrates have been disclosed heretofore. Examples
thereof may ble found in U.S. Patent Nos. 3,574,658;
3,754,976; 4,228,670; 4,312,900; 4,333,840; 4,415,419;
4,552,784; 4,553,417 and 4,753,094.
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W093/03919 PCT/US92/070
2~9 43~ 6 -2-
In this regard, several of the above-noted patents
disclose processes for applying coatings ~o the surface of
worX pieces by a peening or blasting procedure in which
the coating material is applied to the surface by pellets
or other shot material and is impacted at high pressure
against the surface of the worX piece in order to apply
the coating on the pellets or shot to the surface of the
work piece. For example, in U.S. P~tent No. 3,574,658, a
method is disclosed for applying a dry lubricant in the
nature of a molybdenum or tungsten disulfide coating to
the shot material and then applying this dry lubricant
~`~material to the surface of the work piece as a coating.
U.S. Patent No. 3,754,976 discloses a coating process
wherein shot and powdered metal are peened against the
surface of a work piece which has previously been cleaned
with a gentle stream of peening particles in the absenca
cf the coating material. U.S. Patent No. 4,228,670
discloses a process wherein steel or glass shot is
co-mingled with lubricant and blasted against a work piece
20- in order to apply the lubricant to the work piece
surface. U.S. Patent No. 4,312,900 discloses a process
wherein the work piece surface is initially pitted by shot
blasting using abrasive materials such as glass or sand
`~ followed by buffing dry molybdenum disulfide into the pits
created in the surface of the work piece by the shot
blasting. U.S. Patent ~o. 4,552,784 discloses a further
process for applying a ~etal powder to the surface of a
work piece by a peening technique. Again, in U.S. Patent
No. 4,753,094, a process is taught wherein a thin film
coating of molybdenum disulfide is applied to a substrate
surface by a peening action in order to adhere the
molybdenum disulfide to the surface of the substrate as a
coating thereon.
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WO~3~3919 PCT/US92/07062
2~943~
However, none of the prior disclosures have provided
products demonstrating the combination of characteristics
and properties which are achieved by the products of the
present invention nor do they provide processes for
producing such products. Indeed, the need to prolong the
wear-life of substrate surfaces such as metal surfaces and
to reduce the frictional properties thereof in order to
` reduce repair and replacement costs has been and continues
to be the focus of intensive research and development
-- 10 efforts. Nonetheless, these efforts have achieved only
relatively limited success resulting from the use of
previously known coatings, paints and lubricants (both wet
and dry). Each of the known techniques for treating
substrates such as metal surfaces has presented
significant problems and drawbacks in regard to the cost,
difficulties in application, product properties achieved
and the like.
Particularly, it is presently believed that the
processes of the present invention achieve surface
modification whereby plural polymers are bonded wi~h the
surfac~ o~ the treated wo~k piece or substrate. For
purposes hereof, the term bond or bonded will apply to
either physical or chemical bonds which result in products
demonstrating the desired characteristics. Based on this
~elie~, it is presently hypothesized ~hat the surface
finishes of this invention are not coatings but are
permanently bonded with the substrate and can only be
removed by grinding away the substrate surface itself.
Accordingly, the surface-finishing processes of the
present invention result in products with permanent
finishes having a degree of long lasting, durable dry
lubricity and corrosion resistance which has not been
achieved heretofore.
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Wos3/03919 PCT/VS9~/070~
2~9 ~396 ~4~
With regard to prior processes for imparting desirable .-
physical properties of polymers to substrate surfaces such
as metal surfaces, it has been common to employ
fluorocarbon polymers such as t:etrafluoroethylene (TFE)
sold, for example, unde.r the tradename "Teflon" by E.I. Du
Pont de Nemours ~ Co. (Inc.), as a coating material.
Teflon coated surfaces are known to reduce friction and
adhesion but must be applied to the substrate by use of
primers such as epoxy. The coated surface, accordingly,
abrades under modest pressure, does not coat evenly or
thinly and requires high temperatures for application.
_ . . . . .
SUMMARY OF THE INVENTION
-The present invention overcomes many of the known
shortcomings of the prior art. The invention comprises
preparing a particulate mixture of a sulfur containing
metallic compound such as molybdenum disulfide or tungsten
disulfide and a fluorocarbon polymer such as
tetrafluoroethylene, preferably in a ratio of about 1:1 to
about 10:1 parts fluorocarbon polymer to sulfur containing
metallic compound (on a weight percentage basis).
A pressurized stream of the particulate mixture is
impacted onto the surface of a substrate at a sufficient
pressure and for a sufficient period of time to cause
~5 surface modification whereby the particulate mixture
interacts with the substrate. As a result of the
application of such surface finishes to the surface of the
substrate, it has been found that the resulting product
demonstrates outstanding corrosion resistance as well as
long lasting, durable dry lubricity characteristics.
Furthermore, the surface finishes have been found to
provide a relatively thin, impermeable, surface hardened
exterior on the surface of the substrate or work piece.
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W093~039]9 P~T/US92/07062
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These surface finishes have been found to be sufficiently
thin so that the finishes do not interfere with critical
tolerances of any processed parts or components.
Accordingly, it is a general object of the present
invention to provide new and i~proved surface finishes for
` application to substrates and to provide me hods of
applying such surface finishes to substrates.
`~ Another object is to provide corrosion-resistant
surface finishes demonstrating long lasting, durable dry
lubricity characteristics as well as providing an
impermeable, surface hardened outer surface on a substrate.
A further object is to provide methods for producing
; corrosion-resistant, long lasting, durable dry lubricant
surface finishes on substrates.
A f~rther o~ject is to provide a surface finished
product having a high degree of permanent dry lubricity.
Another object is to provide a metal surface
exhibiting long lasting, durable dry lubricity and high
resistance to temperature extremes.
A still further object is to provide methods for
producing thin surface finishes which exhibit long
lasting, durable dry lubricity; corrosion and heat
resistance as well as improved thin film entrapment (or
retention) properties.
Yet another object is to provide methods for
relatively easy and inexpensive application of the surface
finishes of this invention to substrate surfaces. `
Other objects of this invention, in addition to those
set forth above, will become apparent to one of ordinary
skill in the art from the following description.
W093/03919 PCT/US92/07n~2
2~3~ -6-
BRIEF DESCRIPTION OF THE DRAWING
Fig. l is a schematic flow diagram illustrating the
method of the present invention employed to apply a dry
lubricating, corrosion-resistant finish to the surface of
a substrate.
DETAILED DESCRIPTION
The drawing is a schematic rlow diagram showing an
embodiment of the methods of the present invention for
applying surface finishes to a substrate.
In the embodiment of this invention depicted in Fig.
l, a multistep process is illustrated wherein a substrate
surface is first subjected to an optional solvent
precleaning step in ord~r to remove any loose surface
contamination such as hydrocarbons and other physical and
chPmical debris from the substrate prior to further
processing. This precleaning step is employed in order to
reduce contamination which may be encountered and which
may thereby interfere with the blast application of the
surface finish onto the substrate.
The appropriate solvent to be used for this
precleaning is somewhat substrate spacific. For example,
very dirty, greasy substrates will require a Stoddard
solvent to be employed to clean the substrate surface.
For substrate surfaces which are non-degassing, such as
chrome/molybdenum or stainless steel, 1,1,1
trichloroethane or equivalent solvent may be employed in
an ultrassnic cleaning procedureO For degassing
substrates, a Branson IS solvent is employed in an
ultrasonic cleaning procedure.
In a specific solvent precleaning process employed in
the laboratory, a metallic substrate was brush scrubbed in
Stoddard solvent with Hurri-Safe Special Formula Degreaser
WO93~0391s PCT/US92/07062
--7--
20~3~
at a 1:4 dilution in a Hurri Kleen cold part washing
machine and the substrate was then air dried. Thereafter,
the material was cleaned in either Branson IS Formulated
Cleaning Solution, 1:10 dilution or 1,1,1 trichloroethane
precleaner (sold by Brownells) utilizing an indirect
method in a Branson 8200 Ultrasonic Cleaner filled with
Branson IS Formulated Cleaning ',olution, 1:10 dilution.
Cleaning time was about 15 minut:es at 40 C.
As illustrated in the drawing, after completion of the
solvent precleaning step, the substrate is then subjected
to an abrasive cleaning/surface disruption step to create
a sufficient and appropriate amount of disrupted surface
;~ area on the surface of the substrate in order to interact
wi~h the surface finish material to be applied
thereafter. In this abrasive cleaning step, any oxidation
or contamination from the substrate material which was not
removed in the precleaning step is removed.
This abrasive cleaning/surface disruption step may be
performed in a blast cabinet environment in accordance
with the procedures disclosed for precleaning in U.S.
Patent No. 4,753,094 (the disclosure of which is
incorporated herein by reference). The specific
parameters of treatment within this step of the process
are subject to choice, depending on the substrate material
and its intended end use. For example, the delivery
pressure/velocity, temperature, angle of delivery,
duration of blasting and like parameters o~ the process
are subject to choice and will vary depending on whether
final treatment of the substrate is intended to increase
dry lubricity, wear resistance, quick release (i.e.,
non-sticking effect), operative temperature range and/or
corrosion resistance.
W093/039l9 PCT/US92/07~t
2~ 439~ -8-
In regard to the blast materials to be used for this
abrasive cleaning/surface disruption step, it has been
found that for softer, nonferrous metals and alloys,
(e.g., aluminum, copper, lead, magnesium, zinc, beryllium,
gold, tin, bronze, brass, etc.); glass beads, nylon or
plastic particles or aluminum shot may be employed for
blast cleaning the surface of the substrate. For harder,
nonferrous metals (e.g., nickel) and for ferrous metals
and alloys, (e.g., iron, molybdenum, chromium, tungsten,
vanadium, steels and stainless steel) aluminum oxide
particles, silicon carbide particles, glass beads, sand
particles, steei shot and the like may be used to provide
the peening action in cleansing the surface of the
substrate. In this regard, it has been found that less
aggressive media (e.g., glass beads) may be used for
applications where a characteristic such as quick release
or non-sticking is desired, while more aggressive media
such as aluminum oxide or silicon carbide are preferred
for use in applications where end product characteristics
such as increased wear resistance or dry lubricity are
desired.
In regard to the delivery pressures to be employed for
performing this abrasive cleaning step, it is believed
that pressures up to 250 psi may be employed for hard and
very hard substrates such as chrome/molybdenum steels and
tungsten carbides, whereas lower delivery pressures of as
low as about 20 psi may be used in other applications. As
employed herein, the term "delivery pressure" is defined
as the blast pressure applied to a substrate at a distance
of two inches from the nozzle of the delivery device.
The temperature range to be employed in performing
this abrasive cleaning step appears to be a matter of
selection and not to be determinative of the quality of
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WO93/03919 PCT/US92/07062
. .
-9- ~'1396
the surface treatment achieved. However, it has been
found that temperatures ranging between ambient
temperatures and about 50 C are suitable for this
cleaning step.
In specific abrasive cleaning/sllrface disruption
processes employed in the laboratory, substrates which
were to be cleaned/disrupted with aluminum oxide (extra
fine grade-Brownells) utilized a Techni Blast Model 36
Cleaning Machine, sold undar the trademark "SURFGARD" at
58 cubic feet per minute at 100 pounds pressureO This
cleaning machine was eguipped with a 3/16 inch blast gun
with a ceramic nozzle. Alternatively, substrates which
were to be cleaned/disrupted with glass beads (#270 U.S.
Sieve Size-Brownells) were blasted utilizing a Trinco
Direct Pressure Cabinet Nodel 36X30/PC equipped with a 1/4
inch nozzle I~Do and the substrate was blasted at 60-120
psi (preferably about 80-100 psi) at a distance of between
about ~ inches and 12 inches (prefexably about 6-8 inches~
~t an angle of about 20 - 90 (preferably about 30 -
60) until a uniformly disrupted surface was obtained and
all surface contamination was removed.
In step three illustrated in the drawing, the
substrate is air cleaned with dry, compressed air to
- remove any residual cleaning/disrupting media thereby
avoiding any possible cross-contamination with different
media.
Once the preliminary cleaning steps one, two and three
are completed, the substrate is then in condition to be
processed in accordance with the present invention.
In accordance with the present invention, a
pressurized stream of a particulate mixture of a sulfur
containing met:allic compound and a fluorocarbon polymer is
directed in a pressurized stream to impact against the
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WO93/03919 pcT/us92/o7nk2
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--10--
surface of a substxate at a sufficient pressure and for a
sufficient period of time to cause ths particulate mixture
to interact ~ith the substrate and to provide a
surprisingly thin, impermeable, surface hardened,
corrosion-resistant, durable, dry lubricant finish on the
surface of the substrate.
In practice, the substrate s;urface to be treated is
preferably a metallic surface. HQwever, as previously
noted herein, the substrate may be any suitable ferrous or
nonferrous metal or alloy of a metal or a ceramic
composition.
In order to expedite the impacting or peening of the
particulate matter against the surface of the substrate,
it has bean found that suitable peening media having
suitable shot sizes should be employed for purposes of
conveying the mixture to the previously disrupte~ surface
of the substrate. Another purpose of the peening media in
addition to providing a carrier for the surfaca ~inish
particulate material is to surface harden the substrate
through the peening process. A suitable peening medium
for purposes of use in the present process is chosen as a
function of its compatibility with the subs rate and its
affinity for the particulate surface finish material which
it is carrying.
In addition, the size and hardness of the peening
media have been found to influence thP effective transfer
of the surface finish material to the cleansed, disrupted
substrate surface. In this regard, wP have found that
shot sizes ranging from SAE Size No. S70 to about S780
30 (preferably about Size No. S70 and S230; most preferably
about Size S170) may suitably be employed in the processes
of this invention. In particular, we have found that with
softer metal substrates (such as those on the Rockwell B
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WO93/03919 PCT/US92/07062
.
20943~6
scale or on the Rockwell C scale ratings of ~0 and below),
use of larger size shot (such as about SAE Size ~o. 170
and above) is preferred in order to achieve maximum
surface finish coverage. Also, we have found that with
5 harder metals (Rockwell C scalt3 ratings of 40 and above),
such large shot (i.e., SAE No. S170 and above) is likewise
preferred for purposes of achie~ing continuous surface
covsrage. However, it is to be noted that smaller size
shot may also be employed in certain applications to avoid
surface asperities.
Examples of suitable peening media which may be used
herein are steel shot, stainless steel-shot, aluminum ~~
shot, piastic shot and the like having sufficient
structural integrity to withstand impact on the substrate
sur~ace.
In general, the surface finish composition of this
invention is a particulate mixture of solid lu~ricants
formulated to provide dry lubrication and/or corrosion
resistance andJor non-stick properties desired for
purposes of the end use of the product. Suitable solid
lubricants for use in tha particulate mixtures of the
present invention include fluorocarbon polymers and
carrier or binder polymers.
Exemplary of suitable fluorocarbon polymers are
homogenates or mixtures of finely-divided fluorocarbon
resins having fully fluorinated carbon backbones such as
tetrafluoroethylene homopolymer (TF2), hexafluoropropylene
(~FP), perfluoroalkoxyvinyl ether (PPVE), copolymers of
TFE and HFP, copolymers of TFE and PPVE. Other suitable
fluorocarbon polymers are fluoropolymer resins which are
not fully fluorinated such as ethylenetetrafluoroethylene
(ETFE), polyvinylidene fluoride (PVDF), ethylene-
chlorotrifluoroethylene (ECTFE~, copolymers of ethylene
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W093/03919 PCT/US92/070fi2
2~ ~ ~S~9~ -12-
and TFE such as products sold under the trademark "Tefzel"
by E.I. Du Pont de Nemours & Co. (Inc.). The molecular
weight of the fluorocarbon polymers to be used herein may
vary over a relatively wide range although molecular
weights of from about 800 to about 2000 are preferred and,
particularly about lO00-l800. Furthermore, it should be
noted that mixtures of fluorocarbon polymers of varying
molecular weights may be advantageously employed herein
as, for example, mixtures of tetrafluoroethylenes having
molecular weights of llOO and 1300.
In summary, the fluorocarbon pol~mers are chosen for
- their ability to impàrt their individual characteristics
to the substrate and for their affinity to the substrate,
the peening media employed, and/or the other solid
lubricant material chosen. Furthermore, suitable
fluorocarbon polymers ~or use herein are impermeable and
chemically unreactive to water and other solids, W
radiation and gases. The polymers are highly thermally
stable and will withstand high upper surface temperatures
20 ti.e., about 204 C - 260~ C~ as a result of their high
C-F and C-C bond,strengths and the resulting non-polar
nature of the linear polymer. These resins have a low
coefficient of friction and a low dielectric constant and
dissipation factor. They exhibit a high deyree of linear
flexibility and are flame resistant.
The other solid lubricant component of the particulate
mixture employed herein is a sulfur containing metallic
compound which acts as a carrier or binder molecule
herein. Suitable metal sulfides for purposes of the
present invention possess anti-friction/dry lubrication
capabilities, can withstand increased operating
temperatures and/or demonstrate high affinity towards
metals such as those employed as the substrates herein or
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W093/03919 PCT/US92tO7062
2~9433~
the peening media utilized herein as well as demonstrating
high affinity toward the fluorocarbon polymers selected as
part of the surface treatment mixture.
Representative of suitable sulfur containing metallic
compounds for use herein are sulfides of molybdenum,
tungsten, lead, tin, copper, calcium, titanium, zinc,
chromium, iron, antimony, bismuth, silver, cadmium and
alloys and mixtures thereof.
In a preferred form, molybdenum disulfide is employed
as the sulfur containing metal compound in the particulate
mixtures employedO Molybdenum disulfide has a high
affinity to steel and other base metals and has the
ability to increase surface hardness, corrosion
resistance, elevated temperature strength and dry
lubricity. It also has a high affinity to fluorocarbon
micropowders which may be employed advantageously herein.
Thus, it has been found that use of molybdenum disulfide
herein provides the dual function of a dry lubricant
additive as well as a carrier/binder molecule for the
fluorocarbon polymer to promote coating of the peening
media~ '
In general, the amount of fluorocarbon pol~mer to be
incorporated in tha particulate mixture to provide the
requisite surface finish is determined by the amount of
such polymer required to saturate the carrier or binder
molecule such as molybdenum disulfide. The total amount
of the particulate mixture to be employed for applying the
surface finish to the substrate via a peening action in a
blast cabinet is determined by the amount of material
required to keep the peening medium completely coated
during the blasting operation in the cabinet.
In a laboratory example of the practice of the present
invention, a T~echni Blast Model 36 SURFGARD Peen Plating
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WO93/03gl9 PCT/U~92/07~?.
2~9~396
-14-
Machine, 70 cubic feet per minute at 100 pounds pressure,
3/16 inch Suction Blast Gun wit:h Ceramic Nozzle was
employed for directing the part:iculate mixture against the
surface of a substrate in a blast cabinet. The cabinet
was loaded with 500 ml. (by volume) molybdenum disulfide
(Super Fine Grade, Lot #510DS, Climax Molybdenum Co.); 500
ml. (by volume) tetrafluoroethylene having a molecular
weight of about 1100 (Teflon F]uoroadditive Type MP1100,
Lot #BMAB40D002, Du Pont); 500 ml. (by volume)
tetrafluoroethylene having a molecular weight of about
1300 (Teflon Fluoroadditive Type MP1300, Lot #68-86,
Du Pont) and 200 pounds of S70 steel shot (Techni Blast).
The blast cabinet temperature was maintained at about
50 C and the delivery pressure at the nozzle of the peen
plating machine was 80 psi. The particulate mixture with
the peening medium was blasted at a 45 angle at a
distance of about ~-8 inches until a uniform, void-free
surface treatment had been achieved.
After completion of step four in the drawing wherein
the finish surface is applied to the substrate in
accordance with the method of the present invention, it
has been found that the resulting product may
advantageously be subjected to a post-treatment cleaning
and preservation step (step five in the drawing). In this
step of the process, the substrates having the inventive
surface finish applied therein are cleaned with dry,
compressed air to remove any residual surface treatment
particles. Thereafter, the substrate is washed with a
cleaning solution and preserved with an oil that is
compatible with the end use of the material, if so desired.
In a preferred embodiment of the present invention, a
surface finish is produced in the surface of a two inch by
two inch square, 1/4 inch thick chrome/molybdenum steel
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W093/03919 PCT/US92/07052
-15- ~ ~9 ~3g6
sample. The hardness of the chrome/molybdenum steel
sample was 53 as measured on thle Rockwell C scale. In the
process, after subjecting the steel sample ko appropriate
solvent precleaning, the sample was subjected to an
abrasive cleaning/surface disru]ption step in a cabinet
wherein aluminum oxide shot was impacted onto the steel
surface at 60 psi at an angle oE about 45 under ambient
temperature conditions.
Thereafter, the sample was introduced into a blast
cabinet and a Techni Blast Model 36 SURFGARD Peen Plating
Machine having a 3/16 inch Suction Blast Gun with Ceramic
Nozzle was employed t-o`direct a particulate mixture
against the surface of this sample. The particulate
mixture was prepared by mixing 22 ounces (by weight)
tetrafluoroethylene having a molecular weight of about
1500 ~Teflon Fluoroadditive Type MP1500J, Lot #999999) in
a container with lOO lbs. of SAE No. S170 steel shot.
Then, an additional 14.5 ounces (by weight) of
tetrafluoroethylene (MP1500J) was admixed with tha steel
shot in the sama container. In a separate container, 30
ounces (by weight) of molybdenum disulfide (Super Fine
Grade, Lot #~lODS, ~limax Molybdenum Co.) was mixed with
100 lbs. of SAE No. S170 steel shot.
The contents of the two containers were then mixed
together and an additional 24.3 ouncas ~by weight) of
tetrafluoroethylene (MP1500J) was added to the mixture.
The combined mixture contained 60.8 ounces ~by weight)
tetrafluoroethylene, approximately 30 ounces (by weight)
molybdenum disulfide and about 200 lbs. SAE No. S170 steel
shot. The resulting combined mixture contained a ratio by
weight of tetrafluoroethylene to molybdenum disulfide of
about 2:1.
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W093/03919 PCT/VS9Z/070~
2~39~
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The blast cabinet temperature was maintained at about
50 C and the d~livery pressure at the nozzle of the peen
plating machine was 80 psi. The steel shot peening medium
having the particulate mixture intimately coated on the
surface of the shot was blastedl onto the precleaned,
disrupted surface of the sample at an angle of about 450
at a distance of about 4 inches for a period of about 15
seconds to form a uniform, void-free surface on the
surface of the chrome/molybden~m steel sample.
Subsequent to the blast treatment, the sample was
subjected to a post-treatment cleaning step by subjecting
the sample to Stoddard solvent in a Hurri-Kleen Station.
This cleaning step was followed by subsequent cleaning of
the resulting product in 1,1,1 - trichloroethylene in a
15 1000 ml. beaker and the resulting cleaned surface finish
product was subjected to air drying before evaluation.
The resulting product was found to have a
nonabradable, nonetchable surface which was durable,
corrosion resistant and demonstrated dry lubxicity and
20 exceptional wet film entrapment characteristics.
~hus, a method has bèen described herein for producing
a surface finish on a substrate in a manner such that the
resulting product exhibits a wide range of benefits 3
otherwise unavailable. The surface finished product
~5 demonstrates permanent dry lubricity and is highly
resistant to temperature extremes. Furthermore, the
; surface finished product provides a natural barrier to
normal oxidation and corrosion since it is chemically
inert. In addition, the finish in the treated substrate
30 surface exhibits exceptional durability and is extremely
thin, being measured as low as about 0.5 micron thickness
as opposed to prior art coatings wherein the coat is
measured in mils such as the industry standard electroless
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W093/03~9 PrT/US92/07062
-17 2~91~3~
nicXel coatings which have a thickness of 3/8 mil when
submerged in nickel plating solution for 45 minutes at
90.5 C. Still further, the surface finishes of the
present invention are applied relatively easily even at
relatively low temperatures and inexpensively in order to
provide the desired surface modification herein.
The products produced in accordance with this
invention have a multiplicity of uses in a variety of
industries and in products containing metal on metal
friction points or which are subject to metal surface
corrosion. Exemplary of the scope of the utiIization of
the present invention are applications within the
automotive industry, fuel handling systems, power tools
and equipment, fasteners, ball bearings, rollers and other
anti-friction components, consumer products including
cookware, houseware and razor blades, turbines, gears and
other intermeshing machinery as well as a variety of other
potential uses.
Although the invention has been described in its
preferred form with a certain degree of particularity, it
is to be understood that the present disclosure has been
made by way of example only. Numerous changes in the
details and operational steps of the methods and in the
materials utilized therein will be apparent without
~5 departing from the spirit and scope of th~ invention, as
defined in the appended claims.
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