U.S. patent application number 15/047158 was filed with the patent office on 2017-08-24 for component with composite coating for enhanced wear resistance and method for making same.
This patent application is currently assigned to Caterpillar Inc.. The applicant listed for this patent is Caterpillar Inc.. Invention is credited to Daniel Sordelet.
Application Number | 20170241007 15/047158 |
Document ID | / |
Family ID | 59629753 |
Filed Date | 2017-08-24 |
United States Patent
Application |
20170241007 |
Kind Code |
A1 |
Sordelet; Daniel |
August 24, 2017 |
Component with Composite Coating for Enhanced Wear Resistance and
Method for Making Same
Abstract
A component includes a body and a wear layer. The body has a
substrate surface. The wear layer is applied to the body such that
the wear layer is in overlying relationship with at least a portion
of the substrate surface. The wear layer is thermal-spray bonded to
the body. The wear layer comprises a composite of a steel alloy and
a copper alloy.
Inventors: |
Sordelet; Daniel; (Peoria,
IL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Caterpillar Inc. |
Peoria |
IL |
US |
|
|
Assignee: |
Caterpillar Inc.
Peoria
IL
|
Family ID: |
59629753 |
Appl. No.: |
15/047158 |
Filed: |
February 18, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C23C 4/131 20160101;
C23C 4/08 20130101 |
International
Class: |
C23C 4/12 20060101
C23C004/12; C23C 4/06 20060101 C23C004/06 |
Claims
1. A component comprising: a body, the body having a substrate
surface; and a wear layer, the wear layer applied to the body such
that the wear layer is in overlying relationship with at least a
portion of the substrate surface, the wear layer being
thermal-spray bonded to the body, and the wear layer comprising a
composite of a steel alloy and a copper alloy.
2. The component according to claim 1, wherein the composite
includes a volume, the volume including a first volume fraction of
the steel alloy and a second volume fraction of the copper alloy,
and wherein the first volume fraction is at least five percent of
the volume of the composite.
3. The component according to claim 1, wherein the composite
includes a volume, the volume including a first volume fraction of
the steel alloy and a second volume fraction of the copper alloy,
and wherein the first volume fraction is in a range between ten
percent and fifty percent of the volume of the composite.
4. The component according to claim 1, wherein the composite
includes a volume, the volume including a first volume fraction of
the steel alloy and a second volume fraction of the copper alloy,
and wherein the first volume fraction is in a range between
twenty-five percent and fifty percent of the volume of the
composite.
5. The component according to claim 1, wherein the composite
includes a volume, the volume including a first volume fraction of
the steel alloy and a second volume fraction of the copper alloy,
and wherein the first volume fraction and the second volume
fraction are substantially equal to each other.
6. The component according to claim 1, wherein the steel alloy
comprises a carbon steel alloy.
7. The component according to claim 6, wherein the carbon steel
alloy comprises a mild steel alloy containing 0.05 wt %-0.25 wt %
carbon.
8. The component according to claim 6, wherein the carbon steel
alloy comprises a SAE 1080 steel alloy.
9. The component according to claim 1, wherein the steel alloy
comprises a stainless steel alloy.
10. The component according to claim 9, wherein the stainless steel
alloy comprises an austenitic stainless steel alloy.
11. The component according to claim 9, wherein the stainless steel
alloy comprises a SAE 300-series austenitic stainless steel
alloy.
12. The component according to claim 1, wherein the steel alloy
comprises at least one of a carbon steel alloy and an austenitic
stainless steel alloy.
13. The component according to claim 12, wherein the copper alloy
comprises at least one of a copper-zinc alloy and an
aluminum-bronze alloy.
14. The component according to claim 12, wherein the copper alloy
comprises a naval brass alloy.
15. The component according to claim 14, wherein the composite
includes a volume, the volume including a first volume fraction of
the steel alloy and a second volume fraction of the naval brass
alloy, and the first volume fraction and the second volume fraction
being substantially equal to each other.
16. A method of making a component, the component including a body
having a substrate surface, the method comprising: applying, via
thermal spray coating, a wear layer upon the body such that the
wear layer is in overlying relationship with at least a portion of
the substrate surface, the wear layer comprising a composite of a
steel alloy and a copper alloy; allowing the wear layer to solidify
such that the wear layer is bonded to the body.
17. The method of making according to claim 16, wherein the body is
made at least in part from a substrate material, and the steel
alloy and the copper alloy of the composite are both different from
the substrate material.
18. The method of making according to claim 16, wherein the thermal
spray coating includes using a twin wire arc thermal spray
machine.
19. The method of making according to claim 16, wherein the steel
alloy comprises at least one of a carbon steel alloy and an
austenitic stainless steel alloy, and wherein the copper alloy
comprises at least one of a copper-zinc alloy and an
aluminum-bronze alloy.
20. The method of making according to claim 16, further comprising:
machining the body to form the substrate surface, the substrate
surface having a dimension with a value being less than a
specification value; wherein applying the wear layer to the body
upon the body includes depositing the wear layer such that the
value of the dimension when the wear layer is included therein is
increased to be equal to or greater than the specification value.
Description
TECHNICAL FIELD
[0001] This patent disclosure relates generally to components and,
more particularly, to components and methods for making the same
with a composite coating with enhanced wear resistance.
BACKGROUND
[0002] When two surfaces are in contact under conditions of loading
and relative motion, one or both contacting surface can be
subjected to wear damage. For example, if loading is high while
relative motion between the two surfaces is relatively low (e.g.,
as experienced by an oscillating pin joint), then galling (i.e.,
metal-to-metal welding or strong adhesion) can occur and lead to
significant surface damage. Conversely, at higher relative motions
(e.g., as experienced by a connecting rod bearing) and particularly
in poorly-lubricated conditions, then the possibility for one
contacting surface to be worn preferentially exists. Different
contact surface techniques have been developed to resist the
deleterious forms of surface damage.
[0003] For example, U.S. Pat. No. 7,438,979 is entitled, "Thermal
Spray Membrane Contact Material, Contact Member and Contact Part,
and Apparatuses to Which They Are Applied." The '979 patent is
directed to a thermal spray membrane contact material for use in a
bucket connecting apparatus connecting an arm and a bucket by a
work implement connecting pin. The connecting pin comprises a base
material made of steel having an axis function and a contact
surface formed of a thermal spray membrane contact material
film-formed on the base material, said contact surface being placed
at least on a supported surface site of the work implement
connecting pin relative to a bracket and on a slipping contact
surface with a work implement bushing. The thermal spray membrane
contact material is composed of a Mo metal phase, or 10 vol % or
more of a Mo metal phase and a metal phase and/or alloy phase
containing one or more elements selected from the group consisting
of Fe, Ni, Co, Cr, Cu and Zn.
[0004] There is a continued need in the art to provide additional
solutions to enhance the wear resistance of components that can be
subjected to wear damage. For example, many applications are highly
cost sensitive. As such, there is a continued need to provide a
wear-resistant coating solution that uses readily-available,
lower-cost materials that can be processed with economical
equipment to improve the durability and usefulness of a
component.
[0005] It will be appreciated that this background description has
been created by the inventor to aid the reader, and is not to be
taken as an indication that any of the indicated problems were
themselves appreciated in the art. While the described principles
can, in some aspects and embodiments, alleviate the problems
inherent in other systems, it will be appreciated that the scope of
the protected innovation is defined by the attached claims, and not
by the ability of any disclosed feature to solve any specific
problem noted herein.
SUMMARY
[0006] In embodiments, the present disclosure describes a
component. The component includes a body and a wear layer. The body
has a substrate surface. The wear layer is applied to the body such
that the wear layer is in overlying relationship with at least a
portion of the substrate surface. The wear layer is thermal-spray
bonded to the body. The wear layer comprises a composite of a steel
alloy and a copper alloy.
[0007] In another embodiment, a method of making a component is
described. The component includes a body having a substrate
surface. A wear layer is applied, via thermal spray coating, upon
the body such that the wear layer is in overlying relationship with
at least a portion of the substrate surface. The wear layer
comprises a composite of a steel alloy and a copper alloy. The wear
layer is allowed to solidify such that the wear layer is bonded to
the body.
[0008] Further and alternative aspects and features of the
disclosed principles will be appreciated from the following
detailed description and the accompanying drawings. As will be
appreciated, the components and methods of making a component
disclosed herein are capable of being carried out in other and
different embodiments, and capable of being modified in various
respects. Accordingly, it is to be understood that both the
foregoing general description and the following detailed
description are exemplary and explanatory only and do not restrict
the scope of the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a perspective view of an embodiment of a component
constructed in accordance with principles of the present
disclosure.
[0010] FIG. 2 is a longitudinal cross-sectional view of the
component of FIG. 1.
[0011] FIG. 3 is a diagrammatic view of an embodiment of a thermal
spray machine in the form of a twin wire arc thermal spray machine
suitable for use in embodiments of a method of making a component
following principles of the present disclosure.
[0012] FIG. 4 is a flowchart illustrating steps of an embodiment of
a method of making a component following principles of the present
disclosure.
[0013] FIG. 5 are graphs of load (lbf) versus time (seconds), speed
(rpm) versus time (seconds), and coefficient of friction versus
time (seconds) for a block-on-ring test of a specimen of a control
test block having a wear layer made from a composite of naval brass
and molybdenum which was applied using a twin wire arc thermal
spray process using one naval brass thermal spray wire and one
molybdenum thermal spray wire.
[0014] FIG. 6 are graphs of load (lbf) versus time (seconds), speed
(rpm) versus time (seconds), and coefficient of friction versus
time (seconds) for a block-on-ring test, as in FIG. 5, of a
specimen of an exemplary block made according to principles of the
present disclosure having a wear layer made from a composite of
naval brass and SAE 1080 steel which was applied using a twin wire
arc thermal spray process as used for the control specimen of FIG.
5, but using one naval brass thermal spray wire and one SAE 1080
steel thermal spray wire.
[0015] FIG. 7 are graphs of load (lbf) versus time (seconds), speed
(rpm) versus time (seconds), and coefficient of friction versus
time (seconds) for a block-on-ring test, as in FIG. 5, of a
specimen of another exemplary block made according to principles of
the present disclosure having a wear layer made from a composite of
naval brass and SAE 304 stainless steel which was applied using a
twin wire arc thermal spray process as used for the control
specimen of FIG. 5, but using one naval brass thermal spray wire
and one SAE 304 stainless steel thermal spray wire.
[0016] FIG. 8 are graphs of load (lbf) versus time (seconds), speed
(rpm) versus time (seconds), and coefficient of friction versus
time (seconds) for a block-on-ring test, as in FIG. 5, of a
specimen of yet another exemplary block made according to
principles of the present disclosure having a wear layer made from
a composite of naval brass and SAE 316 stainless steel which was
applied using a twin wire arc thermal spray process as used for the
control specimen of FIG. 5, but using one naval brass thermal spray
wire and one SAE 316 stainless steel thermal spray wire.
[0017] It should be understood that the drawings are not
necessarily to scale and that the disclosed embodiments are
sometimes illustrated diagrammatically and in partial views. In
certain instances, details which are not necessary for an
understanding of this disclosure or which render other details
difficult to perceive may have been omitted. It should be
understood, of course, that this disclosure is not limited to the
particular embodiments illustrated herein.
DETAILED DESCRIPTION
[0018] Embodiments of components having a wear layer and methods of
making the same are disclosed herein. In embodiments, a method of
making a component following principles of the present disclosure
can be used to apply a wear layer, via thermal spray coating, upon
a body of the component such that the wear layer is in overlying
relationship with at least a portion of a substrate surface of the
body. In embodiments, the wear layer comprises a composite of a
steel alloy and a copper alloy.
[0019] Turning now to the Figures, there is shown in FIGS. 1 and 2
an exemplary embodiment of a component 50 constructed according to
principles of the present disclosure. The component 50 can be made
using an embodiment of a method following principles of the present
disclosure for applying a wear layer 52 to a substrate surface 54
of a body 55 of the component 50.
[0020] The component 50 of FIG. 1 is shown in the form of a sleeve
bearing. In embodiments, the component 50 can be configured for use
in a final drive assembly of a ground-engaging member (e.g., a
wheel) of a machine, such as an off-highway truck, for example. In
one such arrangement, the component 50 is part of a final drive of
a planetary system for use in a machine, such as, a wheel loader,
for example. The sleeve bearing 50 can be inserted over a pin as
part of a pin joint in the final drive.
[0021] It should be understood that, in other embodiments, the
component 50 can have different forms. For example, in embodiments,
the component 50 can be in the form of a bearing pin, a thrust
bearing, a roller, a seal member, etc. In another arrangement of a
final drive assembly, the component 50, constructed according to
principles of the present disclosure, can be in the form of a pin
and the substrate surface 54 can comprise an exterior surface of
the pin. The wear layer 52 can be applied to the body 55 of the pin
via a suitable thermal spray process. In this arrangement, the
sleeve bearing can be omitted.
[0022] The component 50 includes the body 55 and the wear layer 52.
In the illustrated embodiment, the body 55 comprises a hollow
cylinder. In embodiments, the body 55 of the component 50 can be
made from any suitable material, such as a metal alloy, for
example. In embodiments, the body 55 is made from cast bronze or
wrought bronze.
[0023] In embodiments, the substrate surface 54 of the body 55 can
be treated to facilitate the application of the wear layer 52
thereto. For example, in embodiments, the substrate surface 54 can
be subjected to grit blasting, using any suitable technique as will
be appreciated by one skilled in the art, to help promote the
adhesion of the wear layer 52 to the body 55.
[0024] In embodiments, the wear layer 52 is applied to the body 55
such that the wear layer 52 is in overlying relationship with at
least a portion of the substrate surface 54. In the illustrated
embodiment, the wear layer 52 substantially covers the substrate
surface 54 which is in the form of an exterior cylindrical sidewall
surface of the body 55.
[0025] In some embodiments, a bond layer can be interposed between
the wear layer 52 and the substrate surface 54 of the body 55; in
such embodiments, the wear layer 52 is still considered to be in
overlying relationship with the substrate surface 54 disposed under
the wear layer 52. In at least some of such embodiments, the bond
layer can have a material composition that is different from the
wear layer 52 and/or the body 55.
[0026] In the illustrated embodiment, the substrate surface 54
comprises an exterior cylindrical sidewall surface of the body 55.
In other embodiments, the substrate surface 54 can comprise an
interior surface of the body 55. In embodiments, the wear layer 52
is applied to an exterior and/or an internal sidewall surface of
the sleeve bearing body 55 using a suitable thermal spray process.
For example, in embodiments, the wear layer 52 can be applied to
the body 55 using a suitable thermal spray process, such as a twin
wire arc process. In the illustrated embodiment, the wear layer 52
is thermal-spray bonded to the substrate surface 54 of the body
55.
[0027] The wear layer 52 comprises a composite of a steel alloy and
a copper alloy. In embodiments, the composite from which the wear
layer 52 is made consists essentially of the steel alloy and the
copper alloy. In embodiments, the composite from which the wear
layer 52 is made contains molybdenum in an amount no greater than
ten percent by weight (10 wt %) of the total weight of the
composite, and, in yet other embodiments, no greater than five
percent by weight (5 wt %) of the total weight of the composite. In
embodiments, the steel alloy of the composite from which the wear
layer 52 is made is substantially free of molybdenum (excluding
trace amounts in the steel alloy). In embodiments, the composite
from which the wear layer 52 is made is substantially free of
molybdenum (excluding trace amounts in the steel alloy and/or
copper alloy of the composite).
[0028] In embodiments where the wear layer 52 is applied using a
wire arc spray coating technique, the steel alloy can be supplied
as a coil of wire that is configured to be fed through a thermal
spray machine. In embodiments, the steel alloy of the composite
from which the wear layer 52 is made comprises at least one of a
carbon steel alloy and a stainless steel alloy.
[0029] In embodiments, the steel alloy of the composite from which
the wear layer 52 is made is a carbon steel alloy comprising a mild
steel alloy containing 0.05 wt %-0.25 wt % carbon. In embodiments,
the steel alloy of the composite from which the wear layer 52 is
made is a carbon steel alloy comprising a SAE 1080 steel alloy
according to the SAE International/American Iron and Steel
Institute (AISI) numbering system. In embodiments, the SAE 1080
steel used in the composite from which the wear layer 52 is made
has a chemical composition as follows in Table I:
TABLE-US-00001 TABLE I Chemical Composition Element/Compound Fe C
Mn S P Weight (%) 98.1-98.7 0.75-0.88 0.6-0.9 Up to 0.05 Up to
0.04
[0030] In embodiments, the steel alloy of the composite from which
the wear layer 52 is made is a stainless steel alloy comprising an
austenitic stainless steel alloy. In embodiments, the austenitic
stainless steel alloy used in the composite contains a maximum of
0.15 wt % carbon, a minimum of 16 wt % chromium, and a sufficient
amount of nickel and/or manganese to retain an austenitic structure
over a temperature range between the cryogenic region to the
melting point of the alloy.
[0031] In embodiments, the steel alloy of the composite is a
stainless steel alloy comprising a SAE 300-series austenitic
stainless steel alloy. For example, in embodiments, the wear layer
52 is made from a composite having a SAE 304 stainless steel that
nominally includes 18 wt % chromium and 8 wt % nickel. In
embodiments, the SAE 304 stainless steel used in the composite from
which the wear layer 52 is made has a chemical composition as
follows in Table II:
TABLE-US-00002 TABLE II Chemical Composition Element/Compound
Weight (%) Carbon Up to 0.08 Manganese Up to 2.0 Phosphorus Up to
0.045 Sulfur Up to 0.03 Silicon Up to 0.75 Chromium 18.0-20.0
Nickel 8.0-12.0 Nitrogen Up to 0.1 Iron Balance
[0032] In embodiments, the wear layer 52 is made from a composite
having a SAE 316 stainless steel, also referred to as a
marine-grade stainless steel. In embodiments, the SAE 316 stainless
steel used in the composite nominally includes 17 wt % chromium and
12 wt % nickel. In embodiments, the SAE 316 stainless steel used in
the composite from which the wear layer 52 is made has a chemical
composition as follows in Table III:
TABLE-US-00003 TABLE III Chemical Composition Element/Compound
Weight (%) Carbon Up to 0.08 Manganese Up to 2.0 Phosphorus Up to
0.045 Sulfur Up to 0.03 Silicon Up to 0.75 Chromium 16.0-18.0
Nickel 10.0-14.0 Molybdenum 2.0-3.0 Nitrogen Up to 0.1 Iron
Balance
[0033] In embodiments where the wear layer 52 is applied using a
wire arc spray coating technique, the copper alloy can be supplied
as a coil of wire that is configured to be fed through a thermal
spray machine. In embodiments, the copper alloy of the composite
from which the wear layer 52 is made comprises at least one of a
copper-zinc alloy and an aluminum-bronze alloy.
[0034] In embodiments, the copper alloy of the composite from which
the wear layer 52 is made comprises a copper-zinc alloy referred to
as naval brass, which nominally contain forty percent by weight
zinc and sixty percent by weight copper, but can include other
elements including iron, tin, manganese, and silicon, for example.
In embodiments, the copper alloy of the composite from which the
wear layer 52 is made comprises a copper-zinc alloy referred to as
cartridge brass, which nominally contain thirty percent by weight
zinc and seventy percent by weight copper, but can include other
elements including iron, tin, manganese, and silicon, for example.
For example, in embodiments, the copper alloy of the composite from
which the wear layer 52 is made comprises a naval brass that
nominally includes 60 wt % copper, 0.75 wt % tin, and 39.2 wt %
zinc.
[0035] In embodiments, the copper alloy can be in the form of a
commercially-available thermal spray wire (e.g., 12T wire from
Praxair/TAFA) for use in a suitable wire arc thermal spray machine.
In at least some of such embodiments, the copper alloy is in the
form of a copper-zinc alloy thermal spray wire comprising naval
brass having the following chemical composition in Table IV:
TABLE-US-00004 TABLE IV Chemical Composition Element/Compound Zn Cu
Fe Sn Mn Si Weight (%) 39.50 58.62 0.76 0.92 0.08 0.13
[0036] In embodiments, the copper alloy of the composite from which
the wear layer 52 is made comprises an aluminum bronze which is a
type of bronze in which aluminum is the main alloying metal added
to copper, in contrast to standard bronze (copper and tin) or brass
(copper and zinc). In embodiments, the aluminum bronze used in the
composite from which the wear layer 52 is made nominally includes 5
wt % to 11 wt % aluminum and the balance being copper, but can
include other elements such as iron, nickel, manganese, lead, zinc,
and silicon.
[0037] In embodiments, an aluminum bronze thermal spray wire can
also be used with a steel alloy wire to apply the wear layer 52
using a twin wire arc thermal spray process. In one arrangement the
aluminum bronze wire is a commercially-available thermal spray wire
(e.g., 10T from Praxair/TAFA) and has the following chemical
composition in Table V:
TABLE-US-00005 TABLE V Chemical Composition Total Element/Compound
Others Cu (Including (Balance) Al Mn Pb Zn Si Iron) Weight (%)
92.85 6.90 0.02 0.02 0.17 0.03 0.01
[0038] In embodiments, the composite from which the wear layer 52
is made has a volume. The volume of the wear layer 52 is made up by
a first volume fraction of the steel alloy and a second volume
fraction of the copper alloy. In embodiments, the first volume
fraction of the steel alloy is at least five percent of the volume
of the composite. In embodiments, the first volume fraction of the
steel alloy is in a range between ten percent and fifty percent of
the volume of the composite. In still other embodiments, the first
volume fraction of the steel alloy is in a range between
twenty-five percent and fifty percent of the volume of the
composite.
[0039] In the illustrated embodiment, the first volume fraction of
the steel alloy and the second volume fraction of the copper alloy
are substantially equal to each other. In the illustrated
embodiment, the wear layer 52 is thermal-spray bonded to the
substrate surface 54 of the body 55 of the component 50 using a
twin wire arc spray process in which the steel alloy and the copper
alloy are in the form of separate thermal spray wires having
substantially the same diameter and being fed through the wire arc
thermal spray machine at substantially the same feed rate.
Accordingly, the wire arc thermal spray machine sprayed a composite
made up of the steel alloy and the copper alloy such that the wear
layer 52 applied to the body 55 of the component 50 has a volume
that is substantially made of equal volumetric halves of the steel
alloy and the copper alloy.
[0040] In embodiments, the wear layer 52 can be applied to the body
55 of the component 50 using any suitable thermal spraying
technique, such as one selected from the group including, an
atmospheric plasma spray process, a combustion wire process, a
combustion powder process, an electric arc wire spray process, a
high velocity oxy-fuel (HVOF) coating spray process, and the like,
as known to one of ordinary skill in the art. For example, in
embodiments, a twin wire arc thermal spray process can be used to
apply the wear layer 52 to the body 55 of the component 50.
[0041] Referring to FIG. 3, an embodiment of a wire arc thermal
spray machine 70 is shown. The wire arc thermal spray machine 70
can be used to carry out a method for applying the wear layer 52,
comprising a composite according to principles of the present
disclosure, to the substrate surface 54 of the body 55 of the
component 50. In embodiments, the wire arc thermal spray machine 70
can be used to make the component 50 as any of an original
manufacture, a repair, and/or a remanufacture of the component
50.
[0042] The wire arc thermal spray machine 70 illustrated in FIG. 3
includes a first spool 72 of a first thermal spray wire 73, a
second spool 74 of a second thermal spray wire 75, a power supply
unit 77, a control switch 78, a first feed mechanism 79, a second
feed mechanism 80, a spray torch 82, and a supply of pressurized
gas 84.
[0043] Each of the first thermal spray wire 73 and the second
thermal spray wire 75 are in electrical connection with the power
supply unit 77 such that the first and second thermal spray wires
73, 75 can be selectively supplied with an opposing electrical
polarity via operation of the control switch 78. The first and
second feed mechanisms 79, 80 are configured to selectively feed
the first and second thermal spray wires 73, 75 to the spray torch
82 at a controlled, matched feed rate. The control switch 78 can be
configured to selectively operate the first and second feed
mechanism 79, 80.
[0044] The spray torch 82 includes a first wire passage 88, a
second wire passage 89, and a central gas passage 90. The first
wire passage 88 and the second wire passage 89 are respectively
configured to receive the first thermal spray wire 73 and the
second thermal spray wire 75 therethrough and to route those wires
continuously such that respective distal ends 92, 93 of the first
and second thermal spray wires 73, 75 define an arc gap 95
therebetween that is substantially aligned with an outlet 97 of the
central gas passage 90. The central gas passage 90 is pneumatically
connected to the supply of pressurized gas 84. The supply of
pressurized gas 84 can be configured to selectively propel a flow
of compressed gas 99 through the central gas passage 90 out the
outlet 97 to the arc gap 95.
[0045] In embodiments, the supply of pressurized gas 84 can
comprise any suitable gas for thermal spraying as will be
appreciated by one of ordinary skill in the art. For example, in
embodiments, the supply of pressurized gas 84 can comprise air or
nitrogen as the propelling gas for the wire arc process.
[0046] The wire arc thermal spray machine 70 can be used in a twin
wire arc thermal spray process in which the wire arc thermal spray
machine 70 draws the first and second thermal spray wires 73, 75
from the first and second spools 72, 74, respectively, and feeds
those wires through the spray torch 82 at a controlled, matched
feed rate. An operator can activate the wire arc thermal spray
machine 70 via actuation of the control switch 78 to supply high
electric voltage with opposing charges via the power supply unit 77
between the first thermal spray wire 73 and the second thermal
spray wire 75 at the arc gap 95. The first and second feed
mechanisms 79, 80 respectively feed the first and second thermal
spray wires 73, 75 into close proximity with each other. An
electric arc is discharged therebetween across the arc gap 95
defined at the respective distal ends 92, 93 of the first and
second thermal spray wires 73, 75 that creates sufficient heat to
continuously melt the respective distal ends 92, 93 of the first
and second thermal spray wires 73, 75. The flow of compressed gas
99 propels a composite of atomized molten or semi-molten material
101 from the first and second thermal spray wires 73, 75 onto the
substrate surface 54 of the body 55 of the component 50. The
applied molten particles rapidly solidify on the substrate surface
54 to form a coating of the wear layer 52.
[0047] In embodiments, the first thermal spray wire 73 and the
second thermal spray wire 75 can be made from different materials.
For example, in embodiments, the first thermal spray wire 73 can
comprise a steel alloy and the second thermal spray wire 75 can
comprise a copper alloy such that the wire arc thermal spray
machine 70 applies a composite of the first and second thermal
spray wires 73, 75 upon the substrate surface 54 of the body 55 to
form the wear layer 52. Accordingly, as the first thermal spray
wire 73 and the second thermal spray wire 75 are made up of a steel
alloy and a copper alloy, respectively, the wear layer 52 is made
from a composite that has the same volumetric relationship as found
in and between the first and second thermal spray wires 73, 75.
[0048] In embodiments, the composite of the steel alloy and the
copper alloy in the form of the first thermal spray wire 73 and the
second thermal spray wire 75, respectively, that is applied by the
wire arc thermal spray machine 70 to the substrate surface 54 of
the body 55 to form the wear layer 52 can be any suitable
combination of a copper alloy and a steel alloy as described above.
For example, in embodiments, the first thermal spray wire 73 can be
made from a SAE 1080 steel, and the second thermal spray wire can
be made form a naval brass. In other embodiments, the first thermal
spray wire 73 can be made from a SAE 300-series austenitic
stainless steel alloy (e.g., SAE 304 or SAE 316), and the second
thermal spray wire can be made form a naval brass. In embodiments,
the particular wire types selected for the first and second thermal
spray wires 73, 75 can be determined according to the substrate
material and the intended use of the component in question.
[0049] In embodiments, the first and second thermal spray wires 73,
75 can have substantially the same cross-sectional area and be fed
by the wire arc thermal spray machine 70 at substantially the same
feed rate such that the volume of the composite that forms the wear
layer 52 includes a first volume fraction of the steel alloy and a
second volume fraction of the copper alloy that are substantially
equal to each other. In embodiments, the size and/or feed rate of
one of the first and second thermal spray wires 73, 75 can be
varied to change the relationship between the first volume fraction
and the second volume fraction of the wear layer 52.
[0050] In yet other embodiments, one or more of the first and
second thermal spray wires 73, 75 can comprise a cored wire. For
example, in embodiments, at least one of the first and second
thermal spray wires 73, 75 comprises a cored wire for use in a twin
wire arc thermal spray process that is made by providing a sheet of
copper alloy material and rolling it to form a cylinder. The copper
alloy cylinder is filled with a powder filling of a steel alloy,
and the cylinder seam can be crimped closed to form the thermal
spray wire. In such manner, the relative amount of the copper alloy
and the steel alloy in the composite used to form the wear layer 52
can be varied. In embodiments, the first and second thermal spray
wires 73, 75 comprise cored wires having the same chemical
composition. In other embodiments, the first and second thermal
spray wires 73, 75 comprise two cored wires having different
chemical compositions to provide a spectrum of possible composites
for the wear layer 52.
[0051] In embodiments, the wear layer 52 is made from a composite
that is different from the base material of the body 55 of the
component 50. In embodiments of such cases, the composite from
which the wear layer 52 is made is compatible with the base
material of the body 55 of the component 50 at the substrate
surface 54 such that the wear layer 52 applied to the substrate
surface 54 bonds with the substrate surface 54 of the component 50
after undergoing a thermal spray process. In embodiments of such
cases, the composite from which the wear layer 52 is made can have
at least one enhanced material property relative to the base
material of the substrate surface 54 of the body 55 of the
component 50, such as, wear resistance, fatigue strength, and the
like.
[0052] Although the illustrated embodiment depicts the component 50
in the form of a sleeve bearing, this is only exemplary. It will be
apparent to one skilled in the art that various aspects of the
disclosed principles relating to the thermal spraying of components
can be used with a variety of different types of components.
Accordingly, one skilled in the art will understand that, in other
embodiments, a method of making a component following principles of
the present disclosure can be used to manufacture, repair, or
remanufacture different types of components.
[0053] In embodiments, any suitable thermal spray machine can be
used to carry out a method of making a component in accordance with
principles of the present disclosure to manufacture, repair, and/or
remanufacture the component 50. In embodiments, a method of making
a component following principles of the present disclosure can be
used to make, repair, or remanufacture any embodiment of a
component according to principles discussed herein.
[0054] Referring to FIG. 4, steps of an embodiment of a method 400
of making a component following principles of the present
disclosure are shown. In the method 400 of making, the component
includes a body having a substrate surface. A wear layer is
applied, via thermal spray coating, upon the body such that the
wear layer is in overlying relationship with at least a portion of
the substrate surface (step 410). The wear layer comprises a
composite of a steel alloy and a copper alloy.
[0055] The wear layer is allowed to solidify such that the wear
layer is bonded to the body (step 420). In embodiments, the wear
layer can be subjected to machining to bring the component within a
target range for a specification value for the exterior surface of
the component, including the wear layer.
[0056] In embodiments, the composite can comprise any of the
composite combinations following principles discussed herein. For
example, in embodiments, the steel alloy comprises at least one of
a carbon steel alloy and an austenitic stainless steel alloy, and
the copper alloy comprises at least one of a copper-zinc alloy and
an aluminum-bronze alloy. In still other embodiments, the steel
alloy comprises at least one of a SAE 1080 steel and a SAE
300-series austenitic stainless steel alloy (e.g., SAE 304 or SAE
316), and the copper alloy comprises a naval brass.
[0057] In embodiments, any suitable thermal spray coating technique
can be used. In embodiments, thermal spray coating includes using a
twin wire arc thermal spray machine.
[0058] In embodiments, the component is manufactured from a
suitable material, such as a metal alloy. In embodiments, the body
is made at least in part from a substrate material, and the steel
alloy and the copper alloy of the composite are both different from
the substrate material. For example, in embodiments, the wear layer
can be made from a composite such that the wear layer is harder
than the base material used to manufacture the body of the
component. The wear layer can be disposed over a coverage area of
the substrate surface of the body that is oriented over a wear path
associated with the intended use of the component.
[0059] In embodiments of a method following principles of the
present disclosure, the method can also include machining the body
to form the substrate surface in a remanufacturing operation. The
component can be one that has been removed from service in a
machine system and has been machined to form the substrate surface
to remove material of the body of the component having a defect
therein.
[0060] For example, in embodiments, a component in the form of a
used shaft (e.g., a pin) can be machined (such as on a lathe) to
remove damaged and/or worn material therefrom. The substrate
surface can have a dimension with a value that is less than a
specification value. The step of applying the wear layer to the
body upon the body (step 410) includes depositing the wear layer
such that the value of the dimension when the wear layer is
included therein is increased to be equal to or greater than the
specification value. In embodiments, the wear layer can be
subjected to machining (e.g., grinding) to bring the value of the
dimension within a target range for the specification value. In
embodiments, a conventional or a CNC lathe machine, a milling
machine, and the like can be used for a machining operation. In
other embodiments, machining operations can be performed using
other techniques, such as, grinding, electrical discharge
machining, electrochemical machining, electron beam machining,
photochemical machining, and ultrasonic machining, for example.
INDUSTRIAL APPLICABILITY
[0061] The industrial applicability of the embodiments of a
component and a method of making a component described herein will
be readily appreciated from the foregoing discussion. The described
principles are applicable to a variety of components. For example,
components such as those used in a final drive assembly of a
ground-engaging member (e.g., a wheel) of a machine can be
subjected to relatively harsh conditions while in service resulting
in various forms of wear and/or damage to the component. Using
principles of the present disclosure, a wear layer of a composite
according to principles of the present disclosure that is harder
than the base material from which the body of the component is made
can be applied to the surface of the component to increase the
service time of the component. Using principles of the present
disclosure, a component can also be rebuilt or re-coated with a
wear layer made from a composite including a steel alloy and a
copper alloy according to principles of the present disclosure in a
method of making according to the present disclosure to further
increase the service time of the component.
[0062] In embodiments, a component constructed in accordance with
principles of the present disclosure includes a wear layer made
from a composite of a steel alloy and a copper alloy that provides
enhanced resistance to corrosion, erosion, and/or wear relative to
a base material from which a body of the component is made.
Advantageously, in embodiments, the steel alloy of the composite
from which the wear layer is made has a cost that is less than that
for a comparable amount of molybdenum.
[0063] Surprisingly and unexpectedly, a component constructed
according to principles of the present disclosure having a wear
layer made from a composite formulated according to principles of
the present disclosure can provide similar galling resistance
compared to a wear layer made form a composite using the same
copper alloy but replacing the steel alloy with molybdenum. Test
data for a wear layer made from a composite of molybdenum and naval
brass is shown in FIG. 5. Test data for a wear layer made from a
composite of SAE 1080 steel and naval brass according to principles
of the present disclosure is shown in FIG. 6. Test data for a wear
layer made from a composite of SAE 304 stainless steel and naval
brass according to principles of the present disclosure is shown in
FIG. 7. Test data for a wear layer made from a composite of SAE 316
stainless steel and naval brass according to principles of the
present disclosure is shown in FIG. 8.
[0064] In each instance, a component, which includes a body in the
form of a block and a wear layer applied thereto using a twin wire
arc process, was made under similar conditions, but in which one of
the thermal spray wires was changed as noted. Namely, the
molybdenum wire was replaced with a steel alloy according to
principles of the present disclosure. Each component was subjected
to a block-on-ring test in which the component (block) was placed
into contact with a ring (made from No Cr-4140 steel) that was
rotated relative to the block at 100 rpm and in which the block was
subjected to step loading over time in 25 lbf increments from 50
lbf to 1275 lbf, as shown in the test results.
[0065] Referring to FIGS. 5 and 6, a wear layer according to
principles of the present disclosure, which was made from a
composite of individual steel and brass particles formed from a SAE
1080 steel thermal spray wire and a naval brass (Cu-40Zn) thermal
spray wire in a twin wire arc process, demonstrated comparable
galling resistance to a wear layer made under similar conditions
but replacing the SAE 1080 steel thermal spray wire with a
molybdenum thermal spray wire (at least 99 wt % Mo). In addition,
under the tested conditions, the wear layer according to principles
of the present disclosure which was made from SAE 1080 steel and
naval brass exhibited reduced friction compared to the wear layer
made from molybdenum and naval brass.
[0066] Referring to FIGS. 7 and 8, a wear layer according to
principles of the present disclosure, which was made from a
composite of individual steel and brass particles formed from one
of a SAE 300-series stainless steel thermal spray wire and a naval
brass (Cu-40Zn) thermal spray wire in a twin wire arc process,
demonstrated acceptable galling resistance when compared to the
wear layer of molybdenum and naval brass of FIG. 5. In addition,
the wear layers according to principles of the present disclosure
made from stainless steel in FIGS. 7 and 8 provide enhanced
corrosion resistance.
[0067] It will be appreciated that the foregoing description
provides examples of the disclosed system and technique. However,
it is contemplated that other implementations of the disclosure may
differ in detail from the foregoing examples. All references to the
disclosure or examples thereof are intended to reference the
particular example being discussed at that point and are not
intended to imply any limitation as to the scope of the disclosure
more generally. All language of distinction and disparagement with
respect to certain features is intended to indicate a lack of
preference for the features of interest, but not to exclude such
from the scope of the disclosure entirely unless otherwise
specifically indicated.
[0068] Recitation of ranges of values herein are merely intended to
serve as a shorthand method of referring individually to each
separate value falling within the range, unless otherwise indicated
herein, and each separate value is incorporated into the
specification as if it were individually recited herein. All
methods described herein can be performed in any suitable order
unless otherwise indicated herein or otherwise clearly contradicted
by context.
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