U.S. patent application number 16/581975 was filed with the patent office on 2020-01-30 for coating containing macroparticles and cathodic arc process of making the coating.
The applicant listed for this patent is MDS COATING TECHNOLOGIES CORP.. Invention is credited to Simon Durham, Steve Guetre, Manuel Mendez, Stefan Tzanev.
Application Number | 20200032384 16/581975 |
Document ID | / |
Family ID | 52482868 |
Filed Date | 2020-01-30 |
![](/patent/app/20200032384/US20200032384A1-20200130-D00000.png)
![](/patent/app/20200032384/US20200032384A1-20200130-D00001.png)
![](/patent/app/20200032384/US20200032384A1-20200130-D00002.png)
![](/patent/app/20200032384/US20200032384A1-20200130-D00003.png)
![](/patent/app/20200032384/US20200032384A1-20200130-D00004.png)
United States Patent
Application |
20200032384 |
Kind Code |
A1 |
Durham; Simon ; et
al. |
January 30, 2020 |
COATING CONTAINING MACROPARTICLES AND CATHODIC ARC PROCESS OF
MAKING THE COATING
Abstract
Provided is a method of cathodic arc process for making a
coating containing macroparticles on an airfoil. A structure and/or
composition of the macroparticles is selected to provide
self-healing of the coating in a corrosive environment, and to
provide corrosion resistance and erosion resistance to the coated
airfoil.
Inventors: |
Durham; Simon; (Westmount,
CA) ; Tzanev; Stefan; (St-Lazare, CA) ;
Mendez; Manuel; (Senneville, CA) ; Guetre; Steve;
(Point Claire, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
MDS COATING TECHNOLOGIES CORP. |
St. Laurent |
|
CA |
|
|
Family ID: |
52482868 |
Appl. No.: |
16/581975 |
Filed: |
September 25, 2019 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
14911038 |
Feb 9, 2016 |
10465278 |
|
|
PCT/CA2014/000627 |
Aug 18, 2014 |
|
|
|
16581975 |
|
|
|
|
61867751 |
Aug 20, 2013 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C23C 14/325 20130101;
C23C 14/0688 20130101; C23C 14/14 20130101; C23C 14/06 20130101;
F01D 5/288 20130101 |
International
Class: |
C23C 14/32 20060101
C23C014/32; C23C 14/14 20060101 C23C014/14; F01D 5/28 20060101
F01D005/28; C23C 14/06 20060101 C23C014/06 |
Claims
1. A method of forming a self-healing, corrosion and erosion
resistant coating on an airfoil comprising: inserting an air foil
into a cathodic arc apparatus; vaporizing at least one metallic
cathodic material by applying an arc to the metallic cathodic
material to form atoms, ions and metallic macroparticles of the
metallic cathodic material in an atmosphere within the apparatus so
that the atoms form the coating on the airfoil; and adjusting
parameters of the arc to form liquid, semi-solid, or solid metallic
macroparticles of the metallic cathodic material so that the
metallic macroparticles embed into or onto the coating, wherein a
structure and/or composition of the metallic macroparticles is
selected to provide self-healing of the coating in a corrosive
environment, and to provide corrosion resistance and erosion
resistance to the coated airfoil.
2. The method according to claim 1, wherein the atmosphere
comprises nitrogen and the method further comprises forming the
metallic macroparticles comprising a metal-nitride and the coating
comprising a metal-nitride.
3. The method according to claim 1, wherein the cathodic material
is selected or the arc is applied to provide macroparticles having
a spherical shape.
4. The method according to claim 2, wherein the cathodic material
and the macroparticles comprise titanium.
5. The method according to claim 1, wherein the cathodic material
is selected or the arc is applied in a manner to provide lenticular
macroparticles.
6. The method according to claim 1, wherein the cathodic material
and the macroparticles comprise aluminum.
7. The method according to claim 1, wherein the metallic
macroparticles comprise aluminum and the corrosion resistance is
enhanced by the formation of aluminum hydroxide in a corrosive
environment so that the aluminum hydroxide blocks pores and
crevices in the coating.
8. The method according to claim 1, wherein the coating comprises
multiple layers.
9. The method according to claim 1, wherein the macroparticles
comprise at least one of molybdenum disulphide, vanadium, or
vanadium nitride.
10. The method according to claim 1, wherein the macroparticles
comprise at least 70 at % aluminum to provide the coating with a
sacrificial component that is less noble than the work piece.
11. The method according to claim 1, wherein the macroparticles
comprise at least 90 at % aluminum to provide the coating with a
sacrificial component that is less noble than the work piece.
12. The method according to claim 1, wherein the cathodic material
is deposited as a metal and/or in reactive gas to form a nitride,
carbide, oxide or mixture thereof.
13. The method according to claim 1, wherein the cathodic material
comprises at least one selected from the group consisting of
chromium, aluminum, titanium and other group IV, V and VI
transition metals from the periodic table.
14. The method according to claim 1, wherein the coating comprises
multiple layers.
15. A method of forming a self-healing, corrosion and erosion
resistant coating on an airfoil comprising: inserting the airfoil
into a cathodic arc apparatus; vaporizing a first metallic cathodic
material by applying an arc to the metallic cathodic material to
form atoms, ions and metallic macroparticles of the first metallic
cathodic material in an atmosphere within the apparatus so that the
atoms form the coating on the airfoil; and forming liquid,
semi-solid, or solid macroparticles by applying a second arc to a
second metallic cathodic material under conditions to form the
macroparticles of the second metallic cathodic material so that the
metallic macroparticles embed into or onto the coating, wherein a
structure and/or composition of the macroparticles is selected to
provide self-healing of the coating in a corrosive environment, and
to provide corrosion resistance and erosion resistance to the
coated airfoil.
16. The method according to claim 15, wherein the atmosphere
comprises nitrogen and the method further comprises forming the
metallic macroparticles comprising a metal-nitride and the coating
comprising a metal-nitride.
17. The method according to claim 15, wherein the second cathodic
material is selected or the second arc is applied to provide
macroparticles having a spherical shape.
18. The method according to claim 15, wherein the second cathodic
material and the macroparticles comprise titanium.
19. The method according to claim 15, wherein the second cathodic
material is selected or the second arc is applied in a manner to
provide lenticular macroparticles.
20. The method according to claim 15, wherein the second cathodic
material and the macroparticles comprise aluminum or aluminum
alloy.
21. The method according to claim 15, wherein the macroparticles
comprise at least 70 at % aluminum to provide the coating with a
sacrificial component that is less noble than the workpiece.
22. The method according to claim 15, wherein the macroparticles
comprise at least 90 at % aluminum to provide the coating with a
sacrificial component that is less noble than the workpiece.
23. The method according to claim 15, wherein the cathodic material
is deposited as a metal and/or in reactive gas to form a nitride,
carbide, oxide or mixture thereof.
24. The method according to claim 15, wherein the cathodic material
comprises at least one selected from the group consisting of
chromium, aluminum, titanium and other group IV, V and VI
transition metals from the periodic table.
25. The method according to claim 15, wherein the metallic
macroparticles comprise aluminum and the corrosion resistance is
enhanced by the formation of aluminum hydroxide in a corrosive
environment so that the aluminum hydroxide blocks pores and
crevices in the coating.
26. An airfoil having a surface and a self-healing, corrosion and
erosion resistant coating on the surface formed by the method of
claim 1, wherein the structure and/or composition of the
macroparticles provides the self-healing, corrosion and erosion
resistance to the coating.
Description
[0001] This application is a continuation of U.S. patent
application Ser. No. 14/911,038, filed 9 Feb. 2016, which claims
priority to U.S. provisional patent application Ser. No.
61/867,751, filed 20 Aug. 2014, the complete disclosures of which
are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The invention relates to a cathodic arc method of making a
coating containing macroparticles and a coating containing
macroparticles.
BACKGROUND OF THE INVENTION
[0003] Cathodic Arc Physical Vapor Deposition processes (CAPVD) for
applying coatings to a surface of a work piece are now well known.
CAPVD is also known as ion plasma deposition, as described in U.S.
Pat. No. 6,797,335, the complete disclosure of which is
incorporated herein by reference.
[0004] The CAPVD process is generally conducted by striking an arc
against the surface of a metallic cathodic target material that
vaporizes material from the surface. The vaporized material is
released in the form of highly ionized plasma (atoms) that can
react with a gas on a work piece to form a coating. An example is
titanium (vaporized from the metallic cathodic material) and
nitrogen (the gas) to form a titanium nitride (TiN) coating on the
work piece. Another example is aluminum-titanium-nitride (AITiN or
TiAIN). These coatings are very hard and highly resistant to
erosion.
[0005] An example of a CAPVD process is the Sablev type cathodic
arc source which comprises a short cylindrical shape electrical
conductive target at the cathodic material with one open end, which
is shown in FIG. 1 [Prior Art]. The anode for the apparatus can be
either the vacuum chamber wall or a discrete anode. Arc spots are
generated by mechanical trigger (or igniter) striking an open end
of the cathodic material making a temporarily short circuit between
the cathodic material and anode. After the arc spots have been
generated they can be steered in defined areas of the cathode or
move randomly over the cathode surface depending on the nature and
orientation of the magnetic field around or near the cathode
material.
[0006] The conditions of the CAPVD process can sometimes be such
that un-reacted metal from the cathodic material can form metal
particles in the coating that are referred to as macroparticles.
The presence of these macroparticles is considered a structural
defect in the coating, and can lead to cracks and fissures that
weaken the coating. Thus, CAPVD processes are optimized to avoid
the formation of these macroparticles or filters are used to remove
them. An example of a CAPVD process that uses such a filter is the
Aksenov quarter-torus duct macroparticle filter, shown in FIG. 2
[Prior Art], which consists of a quarter-torus duct bent at 90
degrees from the arc source and the plasma is guided out of the
duct by principle of plasma optics, whereas the macroparticles
continue on a straight path unaffected by the magnetic fields of
the duct.
SUMMARY OF THE INVENTION
[0007] We have now found that the CAPVD process can be modified so
that macroparticles can be shaped, sized, composition altered
and/or quantified to provide desired properties to the coating.
Examples of desired properties are lubrication, hydrophobic,
hydrophilic, corrosion resistance, erosion resistance, surface
texture, electrical resistance or any other desired property. The
macroparticles are formed by the CAPVD process.
[0008] Objectives of the invention can be provided by a method of
forming a coating on a work piece comprising: [0009] inserting a
work piece into a cathodic arc apparatus; [0010] vaporizing at
least one cathodic material by applying an arc to the cathodic
material to form atoms of the cathodic material in an atmosphere
within the apparatus so that the atoms form a coating on the work
piece; and [0011] adjusting parameters of the arc to form liquid,
semi-solid, or solid macroparticles of the cathodic material so
that the macroparticles embed into or onto the coating, wherein a
structure and/or composition of the macroparticles is selected to
provide a desired property to the coating.
[0012] Objectives of the invention can also be obtained by a method
of forming a coating on a work piece comprising: [0013] inserting a
work piece into a cathodic arc apparatus; [0014] vaporizing a first
cathodic material by applying a first arc under conditions to the
first cathodic material to form atoms of the first cathodic
material in an atmosphere within the apparatus so that the atoms
form a coating comprising the first cathodic material on the work
piece; and [0015] forming liquid, semi-solid, or solid
macroparticles by applying a second arc to a second cathodic
material under conditions to form the macroparticles of the second
cathodic material so that the macroparticles embed into or onto the
coating, wherein a structure and/or composition of the
macroparticles is selected to provide a desired property to the
coating.
[0016] Objectives of the invention can be further obtained by a
coated aerofoil comprising: [0017] an aerofoil having a surface;
and [0018] a coating having macroparticles, wherein the coating is
formed on the surface by a cathodic arc process under conditions
which form the macroparticles, wherein a structure and/or
composition of the macroparticles is selected to provide a desired
property to the coating.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 illustrates a prior art cathodic arc process
apparatus;
[0020] FIG. 2 illustrates a prior art cathodic arc process
apparatus;
[0021] FIG. 3 illustrates a cathodic arc process apparatus;
[0022] FIG. 4 illustrates a coating having macroparticles;
[0023] FIG. 5 illustrates a coating having multiple layers; and
[0024] FIG. 6 illustrates a coating having multiple layers with
macroparticles.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0025] The invention will now be explained with reference to that
attached non-limiting Figs.
[0026] An exemplary CAPVD apparatus 2 is shown in FIG. 3 having a
chamber 6 and a source of gas 9 connected to the chamber 6. Three
cathodic materials A, B and C are shown, however, any number of
cathodic materials can be used. The chamber has a turntable 4, upon
which the work piece 8 is placed. During operation an arc is
generated on each of the cathodic materials A, B and C to form an
associated stream 3, 5 and 7 in the general shape of a cone. The
turntable 4 turns during operation exposing the work piece 8 to
each of the streams 3, 5 and 7. The present invention is not
limited by this exemplary CAPVD apparatus 2, and any other desired
CAPVD apparatus may be used to practice the claimed invention.
[0027] At least one of the streams 3, 5 and 7 comprises atoms of at
least one cathodic material A, B or C. The atoms form a coating on
the work piece 8. The atoms can also react with the gas 9 supplied
to the chamber and/or atoms from other streams to form a compound
coating. For example, if the atoms comprise titanium and the gas
comprises nitrogen, the coating can comprise titanium nitride.
[0028] The work piece 8 to be coated is preferably an aircraft
part, such as an airfoil.
[0029] However, if desired the work piece can be any desired
structure, such as drill bits, routers, saw blades, or any other
tool. The work piece 8 can be formed of any desired material, such
as steel, nickel and titanium and alloys thereof.
[0030] Examples of suitable cathodic materials include titanium,
aluminum, chromium and mixtures thereof. Titanium and aluminum are
preferred. Particularly preferred cathodic materials that can be
deposited as metals and/or in reactive gas to form nitrides,
carbides, oxides or mixtures thereof are chromium, aluminum,
titanium and other group IV, V and VI transition metals from the
periodic table, as well as the lanthanide series of metals, such as
but not limited to lanthanum, cerium, neodymium and gadolinium.
[0031] Examples of suitable gases include nitrogen and argon, and
mixtures thereof.
[0032] While nitrogen and argon are preferred, other gases, such as
hydrocarbons, for example acetylene, or oxygen and any other gas,
can be used to provide desired properties to the macroparticles
and/or coating.
[0033] The process is conducted so that at least one of the streams
contains macroparticles comprising a solid, semi-solid or liquid
state of the cathodic material, which embed into and/or onto the
coating. An example of a coating 32 formed on the work piece 8 is
shown in FIG. 4. Macroparticles 34 and 36 are shown as being
embedded into and/or onto the coating 32.
[0034] The properties and composition of the macroparticles can be
adjusted by selecting the cathodic materials and/or gases to
provide the desired properties and composition. The size, shape,
and/or quantity of macroparticles can be varied by adjusting the
process conditions, such as the amperage and/or gas composition. In
general, the greater the amperage the larger the quantity of
particles, the more liquid the particles will be when formed, and
the more lenticular the particles will be when they are deposited
on the surface.
[0035] Without being bound by any theory, we believe that spherical
macroparticles 34 can be formed by using a high melting temperature
material and/or adjusting the arc conditions so that the
macroparticles 34 formed are in a solid or semi-solid state when
contacting the coating 32 so that a spherical shape is maintained.
Examples of high melting materials include titanium. zirconium and
chromium and mixtures of titanium, zirconium and chromium with
other elements. The use of spherical macroparticles 34 generally
results in rough surface on the coating.
[0036] Without being bound by any theory, we believe that
lenticular macroparticles 36 can be formed by using a low melting
temperature material and/or adjusting the arc conditions so that
the macroparticles 36 formed are in a liquid state when contacting
the coating 32 so that the macroparticles 36 flatten during
solidification of the macroparticles 36. Examples of low melting
materials include aluminum and mixtures of aluminum with other
elements. If the long axis of the lenticular macroparticle 36 is
aligned substantially parallel with the coating surface 32, the
coating surface 32 will be smooth. The use of aluminum
macroparticles 36 having a flat lenticular shape has been found to
reduce the formation of conical growth defects that normally form
above spherical macroparticles 34.
[0037] The macroparticles 34, 36 can be formed of materials
selected to provide a desired property to the coating 32.
[0038] To enhance the corrosion resistance of the coating, the
macroparticles 34, 36 can be formed from aluminum or a material
having a high aluminum content. Other suitable sacrificial
materials besides aluminum are zinc or magnesium elements or
alloys. Without being bound by any theory, the corrosion resistance
can be further enhanced by the formation of aluminum hydroxide,
which forms in corrosive environments and blocks pores and crevices
and in so doing prevents corrosive agents from reaching the
substrate, in addition providing self-healing properties.
[0039] A lubricious material, such as molybdenum disulphide,
vanadium, or vanadium nitride, can be used as the particle material
34, 36 to provide the coating with greater lubricity. Molybdenum
disulphide is a solid-state lubricant used widely in the aerospace
industry to reduce wear. Vanadium oxidizes at room temperature and
vanadium nitride oxidizes at higher temperatures and under wear
conditions to form vanadium oxide which is highly lubricious.
Without being bound by any theory it is believed that the presence
of macroparticles comprising materials such as vanadium or
molybdenum disulfide within the coating enhances the lubricious
nature of the coating to reduce the coefficient of friction and
wear rate.
[0040] The macroparticles can also be constructed to provide
hydrophilic, hydrophobic and/or catalytic properties to the
coating. The macroparticles can be provided with the desired
properties by selecting cathodic materials and/or gasses to provide
metals, alloys or compounds in the macroparticles having the
desired properties, which properties are provided to the coating by
the presence of the macroparticles therein.
[0041] The macroparticles can be constructed to lower the corrosion
potential of the coating to below that of the workpiece. For
example, using macroparticles having a high aluminum content, for
example at least 70 at % aluminum, preferably at least 80 at %
aluminum, and more preferably at least 90 at % aluminum, TiAIN
coatings. Without being bound by any theory, it is believed that a
top layer comprising a continuous phase of AIN that surrounds
macroparticles of free aluminum can provide beneficial sacrificial
corrosion properties relative to steels in the galvanic series in
seawater.
[0042] While the cathodic materials A, B and C are shown in the
same plane as the work piece 8 in FIG. 3, if desired, the cathodic
materials A, B and C can be in any desired location. For example, a
cathodic material can be disposed over the coating 32 being formed
so that the macroparticles sputter or splat onto the coating as it
is being formed.
[0043] More than one coating layer can be applied to the work piece
to form the coating 32, as shown in FIG. 5. The different layers
can provide different functionalities. Furthermore, the
macroparticles can be applied to the coating 32 at any time during
the process, such as before the coating 32 is applied, during
application of the coating 32 or different layers of the coating,
and/or after the coating 32 is formed on the work piece 8.
EXAMPLES
[0044] The invention will now be further described with reference
to the following non-limiting experimental examples.
Example 1
[0045] Two coating layers were applied to a work piece using the
following conditions.
[0046] Coating Layer1
[0047] 3 Cathodes
[0048] 2.times.Al
[0049] 1.times.(TiAl)
[0050] Gas=N.sub.2
[0051] Coating Layer 2
[0052] 2 Cathodes
[0053] 2.times.Al
Gas=N.sub.2+Ar
[0054] Reducing the partial pressure of N.sub.2 during the
deposition of layer 2 increased the size of the aluminum
macro-particles 40 as shown in FIG. 6. Also the size of the
macroparticles can be increased by reducing the total pressure. The
free aluminum provides sacrificial corrosion resistance to the
coating and substrate.
[0055] While the claimed invention has been described in detail and
with reference to specific embodiments thereof, it will be apparent
to one of ordinary skill in the art that various changes and
modifications can be made to the claimed invention without
departing from the spirit and scope thereof.
* * * * *