U.S. patent application number 14/097940 was filed with the patent office on 2015-06-11 for coating method, coating system, and coated article.
This patent application is currently assigned to GENERAL ELECTRIC COMPANY. The applicant listed for this patent is GENERAL ELECTRIC COMPANY. Invention is credited to David Vincent BUCCI, Srikanth Chandrudu KOTTILINGAM, Dechao LIN.
Application Number | 20150159257 14/097940 |
Document ID | / |
Family ID | 52133813 |
Filed Date | 2015-06-11 |
United States Patent
Application |
20150159257 |
Kind Code |
A1 |
LIN; Dechao ; et
al. |
June 11, 2015 |
COATING METHOD, COATING SYSTEM, AND COATED ARTICLE
Abstract
A coating method, coating system and coated article are
provided. The coating method includes providing a substrate,
directing a coating material towards the substrate, the coating
material contacting a coating region of the substrate to form a
coating deposit, providing an energy source, and directing the
energy source towards a first peripheral edge portion and a second
peripheral edge portion of the coating region. The directing of the
energy source is concurrent with the directing of the coating
material. The coating system includes a substrate, a thermal spray
nozzle directed towards the substrate, and an energy source
directed towards the substrate. The energy source is configured to
contact only a first peripheral edge portion and a second
peripheral edge portion of a coating region of the substrate. The
coated article includes a substrate, and a uniform thermal spray
coating mechanically bonded to the substrate.
Inventors: |
LIN; Dechao; (Greer, SC)
; BUCCI; David Vincent; (Simpsonville, SC) ;
KOTTILINGAM; Srikanth Chandrudu; (Simpsonville, SC) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
GENERAL ELECTRIC COMPANY |
Schenectady |
NY |
US |
|
|
Assignee: |
GENERAL ELECTRIC COMPANY
Schenectady
NY
|
Family ID: |
52133813 |
Appl. No.: |
14/097940 |
Filed: |
December 5, 2013 |
Current U.S.
Class: |
501/1 ; 118/724;
420/591; 427/446 |
Current CPC
Class: |
C23C 4/12 20130101; C23C
24/04 20130101; B23K 26/0608 20130101; B23K 26/342 20151001; B23K
26/147 20130101; B23K 26/062 20151001; C23C 4/073 20160101 |
International
Class: |
C23C 4/12 20060101
C23C004/12; C23C 4/08 20060101 C23C004/08 |
Claims
1. A coating method, comprising: providing a substrate; directing a
coating material towards the substrate, the coating material
contacting a coating region of the substrate to form a coating
deposit; providing an energy source; and directing the energy
source towards a first peripheral edge portion and a second
peripheral edge portion of the coating region; wherein directing of
the energy source is concurrent with the directing of the coating
material.
2. The coating method of claim 1, wherein directing the coating
material towards the substrate further comprises thermal spraying
the coating material.
3. The coating method of claim 2, wherein thermal spraying the
coating material further comprises cold spraying the coating
material.
4. The coating method of claim 1, wherein providing the energy
source further comprises: selecting the energy source from the
group consisting of a focused high energy beam, a defocused high
energy beam, and a laser beam; wherein the laser beam is selected
from the group consisting of a diode laser, a CO.sub.2 laser, a
fiber laser, and a disc laser.
5. The coating method of claim 4, wherein a laser energy of the
laser beam comprises between 0.5 kw and 6 kw.
6. The coating method of claim 4, wherein a beam width of the laser
beam comprises between 0.1 mm and 5 mm.
7. The coating method of claim 1, further comprising directing the
energy source to increase a density of the coating deposit.
8. The coating method of claim 1, comprising contacting the first
peripheral edge portion and the second peripheral edge portion with
the energy source.
9. The coating method of claim 8, further comprising heating the
coating material without melting the coating material.
10. The coating method of claim 1, wherein providing the energy
source further comprises providing a first energy source and a
second energy source.
11. The coating method of claim 10, further comprising adjusting a
spacing between the first energy source and the second energy
source to control a width of the coating deposit.
12. The coating method of claim 10, comprising contacting the first
peripheral edge portion with the first energy source and the second
peripheral edge portion with the second energy source.
13. The coating method of claim 1, comprising decreasing a velocity
of the coating material contacting the coating region as compared
to the coating method without the energy source.
14. A coating system, comprising: a substrate; a thermal spray
nozzle directed towards the substrate; and an energy source
directed towards the substrate; wherein the energy source is
configured to contact only a first peripheral edge portion and a
second peripheral edge portion of a coating region of the
substrate.
15. The coating system of claim 14, wherein the thermal spray
nozzle comprises a cold spray nozzle.
16. The coating system of claim 14, wherein the energy source
comprises a first energy source and a second energy source.
17. The coating system of claim 14, wherein the first peripheral
edge portion and the second peripheral edge portion comprise up to
40% of the coating region.
18. The coating system of claim 17, wherein a first peripheral edge
portion size is equal to a second peripheral edge portion size.
19. A coated article, comprising: a substrate; and a uniform
thermal spray coating over the substrate; wherein the thermal spray
coating is bonded mechanically to the substrate at all locations of
coverage with an absence of defects.
20. The coated article of claim 19, wherein the uniform thermal
spray coating is a uniform cold spray coating.
Description
FIELD OF THE INVENTION
[0001] The present invention is directed to a coating method, a
coating system and a coated article. More specifically, the present
invention is directed to a hybrid spray coating method, a hybrid
spray coating system, and a hybrid spray coated article.
BACKGROUND OF THE INVENTION
[0002] Many coated articles are formed through thermal spraying of
a coating material. During the thermal spraying, the coating
material is directed towards a substrate at a high velocity. The
coating material contacts the substrate at the high velocity,
generating heat and forming a mechanical bond.
[0003] During the thermal spraying of the coating material, a
peripheral portion of the spray contacts the substrate at a
decreased velocity as compared to a central portion of the spray.
The decreased velocity of the peripheral portion of the spray
decreases the heat generated by the spray. The coating formed from
the peripheral portions of the spray cools at an increased rate,
causing a poor mechanical bond between the coating and the
substrate at such locations.
[0004] One attempt to improve the bonding between the coating and
the substrate includes a preheating of the substrate followed by
thermal spraying. However, the preheating of the substrate could
cause a formation of defects throughout the coating.
[0005] A coating method, coating system and coated article that do
not suffer from one or more of the above drawbacks would be
desirable in the art.
BRIEF DESCRIPTION OF THE INVENTION
[0006] In an exemplary embodiment, a coating method includes
providing a substrate, directing a coating material towards the
substrate, the coating material contacting a coating region of the
substrate to form a coating deposit, providing an energy source,
and directing the energy source towards a first peripheral edge
portion and a second peripheral edge portion of the coating region.
The directing of the energy source is concurrent with the directing
of the coating material.
[0007] In another exemplary embodiment, a coating system includes a
substrate, a thermal spray nozzle directed towards the substrate,
and an energy source directed towards the substrate. The energy
source is configured to contact only a first peripheral edge
portion and a second peripheral edge portion of a coating region of
the substrate.
[0008] In another exemplary embodiment, a coated article includes a
substrate, and a uniform thermal spray coating over the substrate.
The thermal spray coating is bonded mechanically to the substrate
at all locations of coverage with an absence of defects.
[0009] Other features and advantages of the present invention will
be apparent from the following more detailed description of the
preferred embodiment, taken in conjunction with the accompanying
drawings which illustrate, by way of example, the principles of the
invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a side view of a coating method according to an
embodiment of the disclosure.
[0011] FIG. 2 is a top view of a coating method according to an
embodiment of the disclosure.
[0012] Wherever possible, the same reference numbers will be used
throughout the drawings to represent the same parts.
DETAILED DESCRIPTION OF THE INVENTION
[0013] Provided are a coating method, a coating system and a coated
article. Embodiments of the present disclosure, in comparison to
processes and articles not using one or more of the features
disclosed herein, increase bonding of a coating to a substrate,
increase coating efficiency, decrease coating cost, decrease spray
coating velocity, increase uniformity of the coating, remove
coating defects such as cracking, or a combination thereof
[0014] Referring to FIG. 1 and FIG. 2, in one embodiment, a coating
method 100 includes providing a substrate 101, providing an energy
source 102, and directing both a coating material 104 (e.g.
powdered coating material) and the energy source 102 towards a
coating region 105 of the substrate 101 without melting the coating
material 104, the substrate 101, or the coating deposit 106. The
coating material 104 contacts the substrate 101 and forms a coating
deposit 106 on the substrate 101, while the energy source 102
provides heat to the substrate 101, the coating material 104,
and/or the coating deposit 106 without preheating the substrate
101. The coating material 104 is directed toward the coating region
105 by any suitable application method. For example, one suitable
application method includes directing the coating material 104
towards the substrate 101 by thermal spraying of the coating
material 104. Thermal spraying includes, but is not limited to,
vacuum plasma spraying, high velocity oxy-fuel spraying, cold
spraying, other thermal spraying methods, or a combination
thereof.
[0015] In one embodiment, the coating deposit 106 is formed as
application of the coating material 104 and the energy source 102
proceed in a direction of travel 201. In another embodiment, the
application of the coating material 104 includes directing the
coating material 104 towards the substrate 101 with a thermal spray
nozzle 103, which includes, but is not limited to, a cold spray
nozzle. The thermal spray nozzle 103 accelerates the coating
material 104 towards the substrate 101 with any suitable transport
medium such as, but not limited to, nitrogen gas, non-oxidizing
gas, inert gas, or a combination thereof without melting the
substrate 101 or the coating material 104.
[0016] The coating material 104 includes any suitable composition
for thermal spraying to form the coating deposit 106. Suitable
compositions include, but are not limited to, metal matrix
composites, ceramic matrix composites, high melt superalloys, bond
coats such as MCrAlX, PtAl, NiAl, Pt(Ni)Al, or a combination
thereof. The MCrAlX is an alloy having M selected from one or a
combination of iron, nickel, cobalt, and combinations thereof and
Cr is chromium, Al is aluminum, and X is an element selected from
the group of solid solution strengtheners and gamma prime formers
consisting of Y, Tc, Ta, Re, Mo, and W and grain boundary
strengtheners consisting of B, C, Hf, Zr, and combinations
thereof.
[0017] The accelerated coating material 104 exiting the thermal
spray nozzle 103 contacts the substrate 101, generating heat which
facilitates a mechanical bond between the coating material 104 and
the substrate 101. The mechanical bond between the coating material
104 and the substrate 101 forms the coating deposit 106.
Additionally, the acceleration of the coating material 104
generates a predetermined velocity of the coating material 104
exiting the thermal spray nozzle 103. The predetermined velocity is
any suitable velocity capable of generating suitable heat for
forming the coating deposit 106. For example, in one embodiment,
during cold spraying the predetermined velocity of the coating
material 104 accelerated by the cold spray nozzle is up to about
1000 m/s. An increase or decrease in a velocity of the coating
material 104 increases or decreases the heat generated by the
coating material 104 contacting the substrate 101,
respectively.
[0018] In one embodiment, the velocity of the coating material 104
exiting the thermal spray nozzle 103 decreases slightly towards a
periphery of the coating region 105. As such, the velocity of the
coating material 104 contacting the periphery of the coating region
105 is decreased as compared to the rest of the coating region 105,
decreasing the heat generated in the first peripheral edge portion
107 and the second peripheral edge portion 108. In another
embodiment, the conduction of heat generated by the process away
from the coating region 105 increases at the periphery of the
coating region 105, accelerating cooling in the first peripheral
edge portion 107 and the second peripheral edge portion 108. The
decreased heat generated by the decreased velocity and/or the
accelerated cooling from the increased conduction cause the coating
material 104 to bond to the first peripheral edge portion 107 and
the second peripheral edge portion 108 at a peripheral bonding
strength that is significantly reduced as compared to a
non-peripheral bonding strength of the coating material in the rest
of the coating region 105. For example, for a single pass, the
non-peripheral bonding strength includes about 100 MPa, while the
peripheral bonding strength includes, but is not limited to, up to
about 90% of the non-peripheral bonding strength, between about 1%
and about 90% of the non-peripheral bonding strength, between about
1% and about 80% of the non-peripheral bonding strength, between
about 1% and about 50% of the non-peripheral bonding strength,
between about 1% and about 25% of the non-peripheral bonding
strength, between about 1% and about 10% of the non-peripheral
bonding strength, between about 0.5% and about 5% of the
non-peripheral bonding strength, or any combination,
sub-combination, range, or sub-range thereof The non-peripheral
bonding strength may vary between different materials and
applications.
[0019] Without wishing to be bound by theory, the rapid movement of
the reduced heat input at the edges is believed to contribute to
formation of defects such as lack of bonding and cracks. In one
embodiment, to increase the amount of mechanical bonding and/or
decrease cracking seen with pre-heating of the substrate 101, the
energy source 102 provides additional heat to the substrate 101
along the periphery, the coating material 104, and/or the coating
deposit 106.
[0020] The energy source 102 is any suitable energy source such as,
but not limited to, a focused or defocused high energy beam, a
diode laser, a CO.sub.2 laser, a fiber laser, an electron beam, a
disc laser, a scanning laser, or a combination thereof. In one
embodiment, the scanning laser is configured to increase the heat
of the coating material 104 being applied to any suitable portion
of the coating region 105. In an alternate embodiment, the energy
source 102 is positioned outside the thermal spray nozzle 103, in
any suitable configuration for increasing the heat of the coating
material 104 being applied in the first peripheral edge portion 107
and the second peripheral edge portion 108. For example, in one
embodiment, a single energy source 102 provides a U-shaped beam
which contacts the first peripheral edge portion 107, the second
peripheral edge portion 108, and the coating deposit 106 trailing
the thermal spray nozzle 103. Alternate beam shapes include any
suitable shape for increasing the heat of the coating material 104
being applied in the first peripheral edge portion 107 and the
second peripheral edge portion 108, such as, but not limited to, a
rectangular-shaped beam, or a circular-shaped beam. In another
embodiment, a plurality of energy sources 102 provides one or more
split beam(s) that contact at least the first peripheral edge
portion 107 and the second peripheral edge portion 108. In a
further embodiment, at least two energy sources 102 provide at
least one beam directed to either of the first peripheral edge
portion 107 and the second peripheral edge portion 108.
[0021] In one embodiment, a first beam 112 from the energy source
102 contacts the substrate 101 and the coating material 104 in the
first peripheral edge portion 107, and a second beam 113 from the
energy source 102 contacts the substrate 101 and the coating
material 104 in the second peripheral edge portion 108. The
contacting of the energy source 102 with the first peripheral edge
portion 107 and the second peripheral edge portion 108 provides
heat to both the coating material 104 and the substrate 101,
without preheating the substrate 101. The heat softens the first
peripheral edge portion 107 and the second peripheral edge portion
108, without melting the substrate 101 or the coating material 104,
to increase a mechanical bonding strength between the applied
coating material 104 and the substrate 101. The single beam from
the energy source 102 may be split using optics, into a first beam
112 and a second beam 113. In another embodiment, the beam from the
energy source 102 may be rapidly scanned along the first peripheral
edge portion 107 and the second peripheral edge portion 108 as well
as, optionally, the coating deposit 106.
[0022] In one embodiment, the heat from the energy source 102
decreases a rate of cooling of the coating deposit 106, permitting
an increase in the deposition rate of the coating material 104
and/or decreasing or eliminating the formation of cracks in the
coating deposit 106. In another embodiment, the increased heat from
the contacting of the energy source 102 with the first peripheral
edge portion 107 and the second peripheral edge portion 108 permits
a decrease in acceleration of the coating material 104. The energy
source 102 provides any suitable amount of increased heat to
replace the decreased heat from the decreased acceleration of the
coating material 104, and form the coating deposit 106 having
uniform or substantially uniform mechanical bonding to the
substrate 101.
[0023] A density of the coating deposit 106 in the first peripheral
edge portion 107 and the second peripheral edge portion 108 is
locally increased by the increased heat from the energy source 102.
The increased heat coalesces the coating material 104 during
spraying, forming the increase in the density of the first
peripheral edge portion 107 and the second peripheral edge portion
108. In one embodiment, the increase in the density of the first
peripheral edge portion 107 and the second peripheral edge portion
108 forms a uniform or substantially uniform density in the applied
coating deposit 106.
[0024] A positioning of the energy source 102 relative to the
deposit 106, a size of a width of the beam generated by the energy
source 102, a distance between two of the energy sources 102, and a
power range of the energy source 102 control a width of the coating
deposit 106 formed by the application of the coating material 104.
The first peripheral edge portion 107 and the second peripheral
edge portion 108 together are adjusted to occupy any suitable
percentage of the coating region 105, such as, but not limited to,
up to about 40%, between about 1% and about 40%, between about 10%
and about 40%, between about 20% and about 40%, between about 10%
and about 30%, or any combination, sub-combination, range, or
sub-range thereof. In another embodiment, the first peripheral edge
portion 107 and the second peripheral edge portion 108 are similar
or substantially similar in size.
[0025] The energy source 102 generates the beam having any suitable
width and any suitable length for contacting the first peripheral
edge portion 107 and/or the second peripheral edge portion 108 or
otherwise scans these areas. Suitable widths of the beam include,
but are not limited to, up to about 5 mm, between about 0.01 mm and
about 5 mm, between about 0.1 mm and about 3 mm, up to about 2 mm,
or any combination, sub-combination, range, or sub-range thereof.
Suitable lengths of the beam include, but are not limited to, up to
about 15 mm, up to about 10 mm, between about 0.1 and about 10 mm,
or any combination, sub-combination, range, or sub-range thereof.
The width and the length of the beam may vary with differing
conditions, such as, but not limited to, the energy source 102, the
shape of the beam, or the size of the coating region 105. For
example, the diode laser may produce the beam having the
rectangular-shape and a width of between about 0.1 mm and about 1
mm, while the focused high energy beam may produce the beam having
the circular-shape and a width of between about 0.1 mm and about 5
mm.
[0026] The power range for the energy source 102 is adjusted based
upon coating properties, such as, but not limited to, thickness,
speed of application, velocity of application, coating region 105
size, energy source 102 orientation, or a combination thereof. For
example, in one embodiment, during cold spraying of the coating
material 104 the power range for the energy source 102 includes,
but is not limited to, between about 0.1 kw and about 10 kw,
between about 0.1 kw and about 6 kw, between about 0.5 kw and about
6 kw, or any combination, sub-combination, range, or sub-range
thereof.
[0027] While the invention has been described with reference to a
preferred embodiment, it will be understood by those skilled in the
art that various changes may be made and equivalents may be
substituted for elements thereof without departing from the scope
of the invention. In addition, many modifications may be made to
adapt a particular situation or material to the teachings of the
invention without departing from the essential scope thereof.
Therefore, it is intended that the invention not be limited to the
particular embodiment disclosed as the best mode contemplated for
carrying out this invention, but that the invention will include
all embodiments falling within the scope of the appended
claims.
* * * * *