Forming method of wear-resistant strip

Abstract

The invention provides a method for protecting the surface of a nickel-based alloy part, a wear-resistant strip used in the method and a repaired nickel-based alloy part. The method may include spraying a plurality of particles to form a wear strip. The plurality of particles includes a mixture of nickel-based superalloy particles and cobalt-based superalloy particles. The plurality of particles are sprayed at a spray temperature below a melting point of the nickel-based superalloy particles and below a melting point of the cobalt-based superalloy particles. The wear-resistant strip can be attached to the surface of the nickel-based alloy part, and the attachment can be achieved in the particle spraying process (when the wear-resistant strip is formed on the surface of the nickel-based alloy part) and can also be achieved after the wear-resistant strip is independently formed.

Description

Priority information

[0001] This application claims priority to Indian Provisional Patent Application No. 202311064236, filed on September 25, 2023. Technical Field

[0002] This disclosure generally relates to a cold spraying method for forming wear-resistant strips that can be used to protect nickel-based components. Background Technology

[0003] Gas turbine engines typically consist of a turbomachinery core with a high-pressure compressor, a combustion chamber, and a high-pressure turbine arranged in a series configuration. This core operates in a known manner to generate the main airflow. The high-pressure compressor comprises an annular array of stator blades (“rows”) that guide the air entering the engine downstream, thereby rotating the compressor blades. A row of compressor blades and a row of compressor blades together constitute a “stage” of the compressor. Similarly, the high-pressure turbine comprises multiple rows of annular stator nozzle blades that guide the gas exiting the combustion chamber downstream, thereby rotating the turbine blades. A row of nozzle blades and a row of turbine blades together constitute a “stage” of the turbine. Typically, both the compressor and turbine comprise multiple consecutive stages. Attached Figure Description

[0004] This specification provides a complete and effective disclosure of the contents of this disclosure, including its preferred embodiments, as would be understood by those skilled in the art, with reference to the accompanying drawings:

[0005] Figure 1 An exemplary component is shown, which has abrasion-resistant strips formed by a cold spraying process on a first portion of its surface;

[0006] Figure 2 Another exemplary component is shown, which has abrasion-resistant strips formed by a cold spraying process on a first portion of its surface;

[0007] Figure 3A This is a close-up of an exemplary component with wear-resistant strips formed by a cold spraying process;

[0008] Figure 3B This is a close-up of another exemplary component, which has wear-resistant strips formed by a cold spraying process;

[0009] Figure 4 A flowchart illustrating an exemplary method for protecting the surface of a nickel-based alloy component is shown;

[0010] Figure 5 Coating hardness charts of various exemplary wear-resistant strip chemical compositions according to embodiments of the present disclosure are shown; and

[0011] Figure 6 Wear rate graphs of various exemplary wear-resistant strip chemical compositions according to embodiments of the present disclosure are shown;

[0012] Reference characters used repeatedly in this specification and drawings are intended to indicate the same or similar features or elements of this disclosure. Detailed Implementation

[0013] The present embodiments of this disclosure will now be described in detail, with one or more examples illustrated in the accompanying drawings. In the detailed embodiments, features in the drawings are referred to by numbers and letters. Similar names in the drawings and specification have been used to refer to similar parts of this disclosure.

[0014] As used herein, the term "exemplary" means "as an embodiment, example, or illustration." Any implementation described herein as "exemplary" is not necessarily to be construed as being more preferred or advantageous than other implementations. Furthermore, unless specifically indicated, all implementations described herein should be considered exemplary.

[0015] Unless the context clearly indicates otherwise, the singular forms “a,” “a,” and “the / that” include plural references.

[0016] In this disclosure, when a layer is described as being “on” or “above” another layer or substrate, it should be understood that, unless explicitly stated otherwise, the layers may be in direct contact with each other or have another layer or feature between them. Therefore, these terms merely describe the relative positions of the layers and do not necessarily mean “ontop of,” as the relative position above or below depends on the orientation of the device relative to the viewer.

[0017] In this disclosure, chemical elements are discussed using their common chemical abbreviations, such as those commonly found on the periodic table. For example, hydrogen is represented by its common chemical abbreviation H; helium by its common chemical abbreviation He; and so on.

[0018] The term "turbomachinery" refers to a machine that includes one or more compressors, a heating section (e.g., a combustion section), and one or more turbines that together produce torque output.

[0019] The term "gas turbine engine" refers to an engine that has a turbine as its power source, in whole or in part. Exemplary gas turbine engines include turbofan engines, turboprop engines, turbojet engines, turboshaft engines, and hybrid-electric versions of one or more of these engines.

[0020] Gas turbine engines, especially aircraft engines, require frequent and regular maintenance. For example, engine components may wear down during operation and typically require repair to restore their original dimensions and geometry. More specifically, engine components wear down due to friction with adjacent surfaces during use. To restore dimensions, engine components are often repaired with thermal spray coatings. However, the performance of the resulting repair material is degraded due to oxidation, porosity, or both, generated during the thermal spraying process. For particularly damaged components, such as those made of nickel-based superalloys, the thermal spraying process results in higher coating porosity, and surface preparation is required before the thermal spray coating can be applied to restore dimensions. Therefore, there is a pressing need for improved protection processes.

[0021] Methods are typically provided for protecting the surface of nickel-based alloy components, such as nickel-based superalloy components. For example, wear strips can be formed at desired locations where the component may wear down during use. This component can be new or an older component under repair. The wear strips can be formed at the desired locations on the surface of the nickel-based alloy component using a cold spray technique (e.g., directly on the surface), while no wear strips are formed at other locations. Alternatively, the wear strips can be formed separately and then attached to the desired locations on the nickel-based alloy component, while no wear strips are attached at other locations. This attachment can be by adhesive bonding (e.g., bonding) or mechanical connection (e.g., bolted connections, pin connections, screw connections, etc.), allowing the wear strips to adhere to components that experience wear and tear during operation.

[0022] In certain non-limiting embodiments, when wear strips are formed on components that require repair, these components may exhibit wear and tear, necessitating additive manufacturing to supplement the original component material. The wear strip can either act as a replacement material in the worn areas of the component for additive manufacturing, or (if necessary) serve as a sacrificial area to further protect the component surface. In this embodiment, cold spraying techniques can be used to restore nickel-based alloy components to their original shape, with additional additive manufacturing to further protect the component surface. Therefore, the cold spray-based process contemplated herein can reduce waste. Furthermore, the cold spray-based process contemplated herein can also salvage damaged engine components for future use. While other components or articles of manufacture are contemplated in this disclosure, the remainder of this disclosure relates only to components of engines, such as gas turbine engines.

[0023] In one embodiment, the wear strip can be formed using a cold spray process. Compared to alternative deposition methods, the cold spray process requires less heat input during wear strip formation, resulting in a less forged microstructure in the wear strip. This wear strip formation process can produce wear strips with better fatigue strength, superior wear resistance, adjustable hardness, or a combination of these properties. Consequently, protected components can have longer time-on-wing time, extended hardware lifespan, reduced spare parts and maintenance costs, or a combination of these properties.

[0024] refer to Figure 1 An exemplary component 10 is shown, which is in the form of a wing (e.g., a turbine blade) of a turbine engine. However, it should be understood that component 10 is not limited to any particular shape or part and can be any suitable alloy component. In one embodiment, component 10 is formed of a metal or metal alloy. Examples include metals such as nickel, cobalt, titanium, aluminum, zirconium, and copper. Examples of metal alloys include nickel-based alloys, cobalt-based alloys, titanium-based alloys, iron-based alloys, steel, stainless steel, and aluminum-based alloys. As discussed in more detail below, component 10 may be formed of a nickel-based alloy component (i.e., a Ni-based alloy component).

[0025] Refer again Figure 1 Component 10 (e.g., a nickel-based alloy component) has a surface 12 that includes a first portion 14 which may be subject to normal wear during use. In this particular instance, the first portion 14 is shown as the tip of a wing blade.

[0026] like Figure 1 As shown, a spray gun 20 is used to spray a jet 22 of particles 24 onto a first portion 14 of the surface 12 of the component 10. For example, the spray gun 20 may be a cold spray gun configured for a cold spraying method. For example, a cold spraying method may use a spray gun 20 that receives a high-pressure gas and a raw material of particles 24 (e.g., through respective feed pipes 26 and 28). For example, the high-pressure gas may be an inert gas that does not chemically react with the particles 24 or the component 10, including but not limited to argon, helium, nitrogen, air, etc.

[0027] During cold spraying, powder particles are introduced into the airflow in the spray gun 20 under high pressure and ejected from the nozzle 21. The particles 24 are accelerated to high speeds in the airflow, which may reach supersonic speeds. In a particular embodiment, the flow function value of the particles 24 can be less than 10, thereby allowing the particles 24 to flow easily from the nozzle 21 of the spray gun 20.

[0028] Although termed a cold-flow process, the airflow can be heated, but the spraying temperature is kept below the melting point of particles 24 to minimize oxidation and phase transitions of the deposited material during flight. For example, particles 24 can be sprayed at temperatures between 500°C and 1100°C (e.g., 650°C to 1100°C). In one embodiment, particles 24 can be sprayed at relatively lower temperatures (e.g., 500°C to 800°C, such as 650°C to 800°C). In other embodiments, particles 24 can be sprayed at higher temperatures, but still below the melting point of the particulate material (e.g., 800°C to 1100°C, such as 800°C to 950°C). Due to the relatively low deposition temperature (i.e., below the melting point of the particulate material) and very high velocity, the cold-spray process offers the potential to deposit well-adhered, mechanically / metallurgically bonded, dense, hard, and abrasion-resistant strips, the purity of which depends primarily on the purity of the raw material powder used.

[0029] Particle 24 impacts a first portion 14 of the surface 12 of component 10 at high speed. The kinetic energy of particle 24 causes the powder particles of particle 24 to deform and flatten upon impact with component 10. This flattening promotes metallurgical bonding, mechanical bonding, or a combination of metallurgical and mechanical bonding with surface 12, thereby forming a deposit on surface 12 (e.g., within the first portion 14). One advantage of the cold spray method is that phase change or oxidation of particle 24 during flight is negligible or even zero, and the deposited, deformed particles 24 have high adhesion strength.

[0030] By altering the microstructure, morphology, or certain properties of the raw material to reduce the strength or hardness of the particles, softer particulate material can be supplied to the spraying equipment. This allows the softer material to impact and deform on surface 12, thereby forming a dense, high-quality deposit. Some embodiments of the disclosed method involve heat-treating the raw material to alter its material structure and properties, making it suitable for cold spraying. The disclosed method differs from in-situ or internal heat treatment of the raw material during or before spraying. The raw material used herein undergoes heat treatment before entering the cold spraying equipment, thereby altering at least one of its microstructure, morphology, or strength / hardness. Furthermore, the heat treatment received by the raw material in this application differs from heat treatment that can be applied internally to the spray gun equipment.

[0031] like Figure 2As shown, after deposition, particles 24 form a wear-resistant strip 30 on a first portion 14 of the surface 12 of component 10. For example, the thickness of the wear-resistant strip 30 formed on the first portion 14 can be up to 6 mm (e.g., 1.5 mm to 6 mm). In some embodiments, the thickness of the wear-resistant strip 30 on the first portion 14 can be 2.5 mm to 5 mm (e.g., 3.0 mm to 5 mm). Thus, the wear-resistant strip 30 defines a protected portion 13 (covered by the wear-resistant strip 30) on the first portion 14 of the surface 12, leaving an exposed portion 11.

[0032] As described above, before the wear-resistant strip 30 is applied, the first portion 14 of the component 10 may have an untreated surface 12. That is, the wear-resistant strip 30 ( Figure 2 The abrasion strip 30 can be applied directly to the untreated surface 12 without any pretreatment of the first part 14, such as cleaning, degreasing, roughening (e.g., by sandblasting). Therefore, by applying the abrasion strip 30 directly to the untreated surface 12 of the first part 14, the time, cost, and added complexity of pretreatment methods can be avoided.

[0033] Alternatively, the component 10 can be prepared before the abrasion strip 30 is applied. The component 10 is prepared by cold spraying to apply the abrasion strip 30; this preparation may include cleaning or degreasing the surface 12, particularly the first portion 14. In one embodiment, the prepared area of ​​the surface 12 is formed by removing existing material or layers (e.g., oxide layers) from the surface 12 of the component 10, thereby allowing the abrasion strip to be formed directly onto the material of the component 10 for direct bonding with the component 10.

[0034] Particles 24 may comprise metals or metal alloys, such as metals in powder form, refractory metals, alloys, or composite materials. In one embodiment, the composition of particles 24 is compatible with the material of component 10, for example, its composition is substantially the same as the material of component 10 (in its original state). However, in other embodiments, the composition of particles 24 may differ from the material of component 10. It should be noted with reference to the accompanying drawings that... Figure 2 as well as Figure 3A and Figure 3B The crosshairs in the text are for illustrative purposes only, and it should be understood that transition lines may not exist, and the materials may be the same (or different).

[0035] In one particular embodiment, particle 24 is a mixture of nickel-based superalloy particles and cobalt-based superalloy particles. In one particular non-limiting embodiment, the mixture comprises a majority (by weight) cobalt-based superalloy particles (i.e., more than 50 wt% cobalt-based superalloy particles). For example, in one embodiment, the mixture comprises 55 wt% to 95 wt% cobalt-based superalloy particles and 45 wt% to 5 wt% nickel-based superalloy particles, such as 60 wt% to 90 wt% cobalt-based superalloy particles and 40 wt% to 10 wt% nickel-based superalloy particles. In one particular embodiment, the mixture comprises 75 wt% to 85 wt% cobalt-based superalloy particles and 25 wt% to 15 wt% nickel-based superalloy particles.

[0036] Compared to wear strips formed from nickel-based superalloys, the addition of cobalt-based superalloys to the nickel-based superalloy particles increases the strength of the wear strip 30. By making the cobalt-based superalloy particles constitute the majority by weight, the strength of the wear strip 30 can be increased to the required strength and hardness.

[0037] Particularly suitable cobalt-based superalloys are commercially available under the trade name Tribaloy® (Kennametal Stellite). A non-limiting example of a cobalt-based alloy is Tribaloy® T-400 (Kennametal Stellite), which contains, by weight percentage, at least 55.5% cobalt, less than 0.08% carbon (e.g., 0.001% to 0.08%), 8% to 9% chromium (e.g., 8.25% to 8.75%), less than 1.5% iron (e.g., 0.001% to 1.5%), 27.5% to 31% molybdenum (e.g., 28% to 30%), less than 1.5% nickel (e.g., 0.001% to 1.5%), 2.5% to 3% silicon (e.g., 2.75% to 2.85%), and less than 1.0% of other elements. Other examples of cobalt-based alloys may include, but are not limited to, Tribaloy® T-400 cobalt alloy, Tribaloy® T-800, Tribaloy® T-400C cobalt alloy, Tribaloy® T-700 nickel alloy, Tribaloy® 745, Tribaloy® T-401 cobalt alloy, etc.

[0038] In a non-limiting example where the composition of particle 24 differs from that of component 10, the mixture also includes nickel-based superalloy particles, making the coefficient of thermal expansion (CTE) of the wear-resistant strip closer to that of the nickel-based superalloy of component 10. In a particular embodiment, the nickel-based superalloy particles may comprise a nickel-based superalloy with a composition substantially the same as that of the initially formed nickel-based alloy component 10. For example, the nickel-based superalloy particles may comprise a nickel-based superalloy as described below for the material of component 10 (e.g., trade names such as INCONEL® or RENE®). While this disclosure covers different compositions of nickel-based superalloy particles, the nickel-based superalloy particles may have a nickel-based alloy composed of, by weight percentage, 50% to 55% nickel, 17% to 21% chromium, 4.75% to 5.50% niobium, 2.8% to 3.3% molybdenum, 0.65% to 1.15% titanium, 0.20% to 0.80% aluminum, up to 1.0% cobalt, with the balance being iron (e.g., INCONEL® 718). Small amounts of other elements such as carbon, manganese, silicon, phosphorus, sulfur, boron, copper, lead, bismuth, and selenium may also be present.

[0039] refer to Figure 3A The mixture of nickel-based superalloy particles and cobalt-based superalloy particles can be controlled by cold spraying to form a wear-resistant strip 30' in which each component has the desired composition. For example, in one embodiment, a relatively uniform wear-resistant strip 30' can be formed (in terms of composition). For example, as a non-limiting example, the wear-resistant strip 30' may contain up to 80% by weight of nickel-based superalloy and the balance of cobalt-based superalloy. Not wishing to be bound by any particular theory, it is believed that due to the different deposition efficiencies of the nickel-based and cobalt-based superalloy particles, the weight percentage of nickel in the composition of the wear-resistant strip 30' may be higher than the weight percentage of nickel in the particles 24. As a non-limiting example, the deposition efficiency of the nickel-based superalloy particles may be higher, resulting in a higher weight percentage of nickel-based superalloy retained in the wear-resistant strip 30' than the weight percentage of cobalt-based superalloy in the particles 24. For example, after deposition of a mixture of particles 24 containing 40% by weight of nickel-based superalloy particles and 60% by weight of cobalt-based superalloy particles, the wear-resistant strip 30' may have a composition of 80% by weight of nickel-based superalloy and 20% by weight of cobalt-based superalloy.

[0040] refer to Figure 3BDuring the cold spraying process, a mixture of nickel-based superalloy particles and cobalt-based superalloy particles with different relative contents of nickel-based superalloy particles and cobalt-based superalloy particles forms a gradient wear strip in the wear strip 30”. Therefore, the cold spraying method can be used to form a wear strip 30” with a gradient wear strip composition. For example, the wear strip 30” may include an innermost layer 52 adjacent to surface 12 and an outermost layer 58 opposite surface 12. Any suitable number of intermediate layers (shown as a first intermediate layer 54 and a second intermediate layer 56) may be located between the innermost layer 52 and the outermost layer 58. Each of these layers may have a different relative composition of nickel-based superalloy particles and cobalt-based superalloy particles. For example, in one embodiment, the innermost layer 52 may have a relatively higher nickel-based superalloy concentration compared to the outermost layer 58, thereby making the coefficient of thermal expansion (CTE) of the wear strip 30” at surface 12 closer to that of component 10. Alternatively, the outermost layer 58 may have a relatively high concentration of cobalt-based superalloy compared to the innermost layer 52, thereby giving the wear-resistant strip 30” a higher hardness at the surface 17 opposite to the surface 12.

[0041] For example, the composition of the wear-resistant strip 30” can transition from a relatively high nickel-based superalloy concentration at the innermost layer 52 to a relatively low nickel-based superalloy concentration at the outermost layer 58, and conversely, from a relatively low cobalt-based superalloy concentration at the innermost layer 52 to a relatively high cobalt-based superalloy concentration at the outermost layer 58. Intermediate layers 54, 56, etc., can transition the composition from the innermost layer 52 to the outermost layer 58, for example, through a stepped gradient transition (making the change non-linear), or through a continuous transition (making the relative concentrations of nickel-based and cobalt-based superalloys continuously change). Furthermore, although... Figure 3B For ease of illustration, the layers are shown as straight lines, but it should be understood that they may alternatively follow the outline of defect 16 in Part 14, or have other alternative shapes, outlines or forms.

[0042] In one embodiment, multiple spray guns can be used to form this varied wear-resistant strip composition, wherein at least one spray gun is dedicated to nickel-based superalloy particles and at least another spray gun is dedicated to cobalt-based superalloy particles. Alternatively, the composition of the mixture can be intermittently changed during cold spray deposition to form a gradient wear-resistant strip. Alternatively, the composition of the mixture can be intermittently or continuously changed during cold spray deposition to form a gradient throughout the wear-resistant strip.

[0043] In certain non-limiting embodiments, the wear-resistant strip may be heat-treated to further improve its wear resistance and strength. Heat treatment of the wear-resistant strip can further enhance the mechanical properties of the wear-resistant strip applied by cold spraying. While it should be understood that heat treatment can be applied to any of the aforementioned wear-resistant strips, it should also be understood that such heat treatment is optional. The remainder of this disclosure will only discuss the wear-resistant strip 30 and optional heat treatment. In another non-limiting example, the cold-sprayed wear-resistant strip 30 may be heated simultaneously during the cold spraying process to reduce or eliminate the need for post-spraying heat treatment. For example, refer again... Figure 1 During the formation of the abrasion strip, a hot air gun 34 (or other heating device) can be used to direct heat energy 32 to the surface 12. In one embodiment, during the cold spraying process, the abrasion strip 30 is heated to a processing temperature of 250°C to 1000°C (e.g., 400°C to 500°C).

[0044] However, in other embodiments, post-spray heat treatment can be performed to heat the applied abrasion strip 30. For example, heat can be directed to the abrasion strip 30 after its formation (e.g., using a hot air gun, hot isostatic press, or other heating device). Alternatively, the component 10 can be placed in an oven for heating to heat-treat the abrasion strip 30. In one embodiment, the abrasion strip 30 is heated to a treatment temperature of 900°C to 1300°C (e.g., 1000°C to 1200°C) after being formed by cold spraying. Such heat treatment can be performed for at least 30 minutes, for example, from 30 minutes to 5 hours (e.g., 1 hour to 4 hours).

[0045] In one embodiment, the wear strip 30 has a high density, which may result in increased hardness and wear resistance of the first portion 14 of the component 10. For example, after heat treatment of the deposited wear strip, the porosity of the wear strip 30 can be below 5% (e.g., 0.1% to 5%). The resulting wear strip 30 can have higher wear resistance compared to the original nickel-based alloy component. Without wishing to be bound by any particular theory, it is believed that the enhanced mechanical properties of the wear strip after heat treatment are due to the formation of a γ' phase and diffusion bonding (e.g., as shown in the image) at the interface 19 between the surface 12 and the wear strip 30. Figure 3A and 3B (As shown). Heat treatment can also seal any delamination at the interface of the wear-resistant strip 30 and may form diffusion bonds with the underlying layer / surface.

[0046] In one embodiment, the average particle size of the cobalt-based alloy particles and nickel-based alloy particles in the mixture is 10 µm to 40 µm (e.g., 10 µm to 30 µm). These particle sizes are large enough for use in cold spraying processes, yet small enough to form grains within the deposited wear-resistant strip 30.

[0047] As previously stated, in one embodiment of the cold spraying method proposed herein, the mixture does not melt during cold spraying. In one embodiment, the melting point of the mixture is higher than the temperature experienced by the mixture during cold spraying. In a further embodiment, the temperature experienced by the mixture is less than 0.9 times the melting point of the mixture (i.e., the cobalt-based alloy particles and the nickel-based alloy particles).

[0048] In one embodiment, a carrier gas is used to transport the mixture for deposition, such as helium, nitrogen, atmospheric air, argon, or any combination thereof. In one embodiment, the carrier gas temperature is 20°C to 1200°C (e.g., 500°C to 1100°C, such as 650°C to 1100°C). Typically, in cold spraying processes, the critical impact velocity of the raw material is defined as below which the adhesion between the particles and surface 12 is useless for the intended application. The critical impact velocity of the raw material may depend on the nature and characteristics of the particles 24 and the component. In one embodiment, operating the cold spraying apparatus used herein involves accelerating the particles 24 to a speed of 500 m / s to 1100 m / s.

[0049] Figure 4 An exemplary method 40 for forming a wear-resistant strip is shown. This strip can be formed as a separate strip to be attached to a component surface, or it can be formed directly on the component surface, and can include any of the foregoing descriptions. At 42, a particle stream is sprayed onto a forming surface (e.g., a transfer surface or a component surface) to form the wear-resistant strip. At 44, any oversprayed particles are optionally removed from the surface, which is particularly relevant to embodiments where the particle stream is sprayed directly onto the component surface. For example, oversprayed portions of the wear-resistant strip can be removed by methods such as machining (e.g., grinding), chemical etching, etc. At 46, as described above, the wear-resistant strip can optionally be heat-treated. In particular, the wear-resistant strip can be heat-treated on the component surface to aid bonding. Through this method 40, the wear-resistant strip (e.g., ...) is formed. Figure 1 , 2 The wear-resistant strips 30, 30', and 30") in 3A and 3B may be composed of 5% to 80% nickel-based superalloy and 20% to 95% cobalt-based superalloy, for example, 10% to 60% nickel-based superalloy and 40% to 90% cobalt-based superalloy (e.g., 15% to 50% nickel-based superalloy and 50% to 85% cobalt-based superalloy).

[0050] Refer again Figure 1As described above, in some embodiments, component 10 is formed of a nickel-based alloy. Component 10, wear strip 30, or both may be formed of a nickel-based superalloy. Exemplary nickel-based superalloys are commercially available under the trade names INCONEL® (Special Metals, Inc.) or RENE® (Teledyne Industries, Inc., Los Angeles, California). While this disclosure covers various component materials, the following description of the component uses a nickel-based alloy as the component material (as a particular embodiment). A non-limiting example of a nickel-based alloy is INCONEL® Alloy 718 (Special Metals, Inc., Hartford, NY), which comprises, by weight percentage, 50% to 55% nickel, 17% to 21% chromium, 4.75% to 5.50% niobium, 2.8% to 3.3% molybdenum, 0.65% to 1.15% titanium, 0.20% to 0.80% aluminum, up to 1.0% cobalt, and the balance iron. Small amounts of other elements may also be present, such as carbon, manganese, silicon, phosphorus, sulfur, boron, copper, lead, bismuth and selenium (all less than 1% by weight).

[0051] Strengthened nickel-based alloys typically contain precipitated phases, such as γ′ and γ″ phases, as well as high-temperature precipitates, such as carbide, oxide, boride, and nitride phases. These phases may exist individually or in combination, depending on the alloy composition and heat treatment conditions. In some embodiments, at least one of the δ, σ, η, μ, or lanes phases may also be present. Precipitated phases such as γ′ and γ″ in nickel-based alloys typically dissolve during solution heat treatment and recrystallize during cooling from the solution temperature and subsequent aging heat treatment. As a result, at least one γ′ phase or γ″ secondary phase is distributed in the nickel alloy matrix. High-temperature precipitates, such as carbide, oxide, boride, and nitride phases, typically do not dissolve during solution heat treatment and may therefore remain as precipitates even after solution heat treatment of the alloy.

[0052] In typical precipitation-strengthened nickel alloys, the alloy first undergoes a solution treatment (or, in art terms, a "solutionization"), in which the alloy is heated to a temperature above the solution line (solvus) of the precipitates. The precipitates referred to herein can be "primary," "secondary," or "tertiary" precipitates formed at different temperature treatment stages, rather than high-temperature carbide, oxide, boride, or nitride phases that may still exist even above the solution line temperature of primary / secondary / tertiary precipitates.

[0053] Typically, alloys undergo solution treatment followed by quenching to form a supersaturated solid solution phase. In one embodiment, the matrix comprises a nickel-based γ phase. The γ phase is a solid solution of different types of atoms with a face-centered cubic (fcc) lattice and random distribution. In some alloys where high-temperature precipitates are present, the supersaturated solid solution phase may still contain precipitates of these high-temperature phases. In one embodiment, for example in γ' phase systems such as Rene 88® or Waspaloy®, the γ' phase may precipitate rapidly even during quenching. Generally, as described below, alloys in the solution state, even with precipitation during quenching, have significantly lower hardness than alloys in the fully machined state.

[0054] In the third step, the supersaturated solid solution phase is heated to below the solid solution temperature of the precipitate to generate fine, dispersed precipitates. For example, in a γ′′ phase system, the γ′′ phase may precipitate in large quantities during aging treatment, thereby hardening and strengthening the alloy.

[0055] Therefore, strengthening nickel-based alloys typically involves a well-designed solution heat treatment method that dissolves the γ′ or γ′′ strengthening phases, which are then optimally re-precipitated during the heat treatment cooling process or after subsequent solution alloy aging. The cooling rate and path applied to nickel-based alloy components, along with the temperature and time of the aging treatment, together with the inherent characteristics of the specific composition, generally influence the formation of optimal properties in nickel-based alloys.

[0056] The following clauses provide further details:

[0057] A method comprising: spraying a plurality of particles to form a wear-resistant strip, wherein the plurality of particles comprises a mixture of nickel-based superalloy particles and cobalt-based superalloy particles, the plurality of particles being sprayed at a spraying temperature below the melting point of the nickel-based superalloy particles and below the melting point of the cobalt-based superalloy particles.

[0058] The method according to any of the foregoing clauses further includes: attaching the wear-resistant strip to the surface of the nickel-based alloy component.

[0059] According to the method described in any of the foregoing clauses, the wear-resistant strip is formed directly on the surface of the nickel-based alloy component to be bonded.

[0060] The method according to any of the foregoing clauses, wherein the surface of the nickel-based alloy component is untreated when the plurality of particles are sprayed onto the surface of the nickel-based alloy component.

[0061] The method according to any of the foregoing clauses, wherein the wear-resistant strip is formed separately and attached to the surface of the nickel-based alloy component.

[0062] The method according to any of the foregoing clauses further includes: heat-treating the wear-resistant strip on the surface of the nickel-based alloy component, wherein heat-treating the wear-resistant strip includes heating the wear-resistant strip to above 1000°C and holding it for at least 30 minutes, and the wear-resistant strip has a porosity of less than 2% after heat treatment.

[0063] According to the method described in any of the foregoing clauses, the thickness of the wear-resistant strip on the surface of the nickel-based alloy component is 1 mm to 6 mm.

[0064] According to the method described in any of the foregoing clauses, the wear-resistant strip forms a ring.

[0065] The method according to any of the foregoing clauses, wherein the mixture comprises more than 50% by weight of cobalt-based superalloy particles.

[0066] According to the method described in any of the foregoing clauses, the cobalt-based superalloy particles account for 55% to 95% by weight of the mixture, and the nickel-based superalloy particles account for 5% to 45% by weight of the mixture.

[0067] According to the method described in any of the foregoing clauses, the nickel-based superalloy particles account for 10% to 40% by weight of the mixture, and the cobalt-based superalloy particles account for 60% to 90% by weight of the mixture.

[0068] According to the method described in any of the foregoing clauses, the wear-resistant strip contains nickel-based superalloy particles and cobalt-based superalloy particles in different relative proportions.

[0069] The method according to any of the foregoing clauses, wherein the wear-resistant strip has a gradient structure along its entire thickness direction.

[0070] According to the method described in any of the foregoing clauses, the wear-resistant strip is formed directly on the surface of the nickel-based alloy component to be bonded, the wear-resistant strip comprising an internal content of nickel-based superalloy particles located at the interface of the nickel-based alloy component, and an external content of nickel-based superalloy particles located opposite the interface, wherein the weight percentage of the internal content of the nickel-based superalloy particles is greater than the weight percentage of the external content of the nickel-based superalloy particles.

[0071] According to the method described in any of the foregoing clauses, the wear-resistant strip is formed directly on the surface of the nickel-based alloy component to be bonded, the wear-resistant strip having an internal content of cobalt-based superalloy particles located at the surface of the nickel-based alloy component, and an external content of cobalt-based superalloy particles located opposite the surface of the nickel-based alloy component, wherein the weight percentage of the internal content of the cobalt-based superalloy particles is greater than the weight percentage of the external content of the cobalt-based superalloy particles.

[0072] According to the method described in any of the foregoing clauses, the nickel-based superalloy particles comprise a nickel-based superalloy comprising, by weight percentage: 50% to 55% nickel, 17% to 21% chromium, 4.75% to 5.50% niobium, 2.8% to 3.3% molybdenum, 0.65% to 1.15% titanium, 0.20% to 0.80% aluminum, up to 1.0% cobalt, and the balance being iron.

[0073] The method according to any of the foregoing clauses, wherein the average size of the nickel-based superalloy particles is 10µm to 40µm, and the average size of the cobalt-based superalloy particles is 10µm to 40µm.

[0074] According to the method described in any of the preceding clauses, the cobalt-based superalloy particles comprise a cobalt-based superalloy containing, by weight percentage, at least 55.5% cobalt, less than 0.08% carbon, 8% to 9% chromium, less than 1.5% iron, 27.5% to 31% molybdenum, less than 1.5% nickel, 2.5% to 3% silicon, and less than 1.0% other elements.

[0075] According to the method described in any of the preceding clauses, the plurality of particles are carried by a high-pressure airflow, the high-pressure airflow being heated to the spraying temperature, the spraying temperature being 500°C to 1100°C.

[0076] The method according to any of the preceding clauses, wherein the surface of the nickel-based alloy component is untreated when the plurality of particles are sprayed onto the surface of the nickel-based alloy component. A nickel-based alloy component formed according to the method according to any of the preceding clauses.

[0077] A nickel-based alloy component includes: a wear-resistant strip formed on the surface of the nickel-based alloy component by the method described in any of the preceding clauses.

[0078] A nickel-based alloy component includes: a wear-resistant strip located on the surface of the nickel-based alloy component, the wear-resistant strip comprising a plurality of deformable particles, the plurality of deformable particles comprising 5% to 80% by weight of nickel-based superalloy and 20% to 95% by weight of cobalt-based superalloy.

[0079] Example

[0080] Figure 5The coating hardness (Hv) of an exemplary wear-resistant strip formed from particles 24 with three different chemical compositions is shown. The particle chemical composition labeled "100% Ni" refers to a wear-resistant strip formed using a cold spraying method that uses 100% by weight nickel-based superalloy particles commercially available under the trade name INCONEL® 718. The mixture chemical composition labeled "60% Co, 40% Ni" refers to a wear-resistant strip formed using a cold spraying method that uses a mixture of 60% by weight cobalt-based superalloy particles commercially available under the trade name Tribaloy® T-400 and 40% by weight nickel-based superalloy particles commercially available under the trade name INCONEL® 718. The chemical composition of the mixture labeled "80% Co, 20% Ni" refers to the wear-resistant strip formed using a cold spraying method that employs a mixture of 80% by weight cobalt-based superalloy particles (commercially available under the trade name Tribaloy® T-400) and 20% by weight nickel-based superalloy particles (commercially available under the trade name INCONEL® 718). Figure 5 As shown, the coating hardness increases with the relative content of cobalt-based superalloys in the mixture used in the corresponding cold spraying method.

[0081] Figure 6 The wear rates (mm) of three different mixture chemical compositions and the uncoated surfaces of nickel parts are shown. 3 / Nm×10 -5 (Comparison) The uncoated part is formed from 100% INCONEL® 718. The particle chemical composition marked "100% Ni" refers to a wear-resistant strip formed using a cold spray method that uses 100% by weight nickel-based superalloy particles commercially available under the trade name INCONEL® 718. The mixture chemical composition marked "60% Co, 40% Ni" refers to a wear-resistant strip formed using a cold spray method that uses a mixture of 60% by weight cobalt-based superalloy particles commercially available under the trade name Tribaloy® T-400 and 40% by weight nickel-based superalloy particles commercially available under the trade name INCONEL® 718. The chemical composition of the mixture labeled "80% Co, 20% Ni" refers to the wear-resistant strip formed using a cold spraying method that employs a mixture of 80% by weight cobalt-based superalloy particles (commercially available under the trade name Tribaloy® T-400) and 20% by weight nickel-based superalloy particles (commercially available under the trade name INCONEL® 718). Figure 6 As shown, the wear rate decreases significantly with the increase of the relative content of cobalt-based superalloy in the mixture used in the corresponding cold spraying method.

[0082] This written specification discloses the invention (including the best mode) by way of example and also enables those skilled in the art to practice the invention (including making and using any device or system and performing any combined methods). The patentable scope of this disclosure is defined by the claims and may include other examples that may occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they comprise structural elements that are identical to the written language of the claims, or if they comprise equivalent structural elements that are not substantially different from the written language of the claims.

Claims

1. A method, the method comprising: Multiple particles (24) are sprayed to form a wear-resistant strip (30). The multiple particles (24) comprise a mixture of nickel-based superalloy particles and cobalt-based superalloy particles. The multiple particles (24) are sprayed at a spraying temperature lower than the melting point of the nickel-based superalloy particles and lower than the melting point of the cobalt-based superalloy particles.

2. The method according to claim 1, wherein, The method further includes: The wear-resistant strip (30) is attached to the surface (12) of the nickel-based alloy component (10).

3. The method according to any one of the preceding claims, wherein, The wear-resistant strip (30) is formed directly on the surface (12) of the nickel-based alloy component (10) to be bonded, or the wear-resistant strip (30) is formed separately and attached to the surface (12) of the nickel-based alloy component (10).

4. The method according to any one of the preceding claims, wherein, The method further includes: The wear-resistant strip (30) on the surface (12) of the nickel-based alloy component (10) is subjected to heat treatment, wherein the heat treatment of the wear-resistant strip (30) includes heating the wear-resistant strip (30) to above 1000°C and holding it for at least 30 minutes, and the porosity of the wear-resistant strip (30) after heat treatment is below 2%.

5. The method according to any one of the preceding claims, wherein, The wear-resistant strip (30) has a thickness of 1 mm to 6 mm on the surface (12) of the nickel-based alloy component (10).

6. The method according to any one of the preceding claims, wherein, The wear-resistant strip (30) forms a ring attached to the surface (12) of the nickel-based alloy component (10).

7. The method according to any one of the preceding claims, wherein, The mixture contains more than 50% by weight of cobalt-based superalloy particles, preferably, the cobalt-based superalloy particles account for 55% to 95% by weight of the mixture and the nickel-based superalloy particles account for 5% to 45% by weight of the mixture, more preferably, the nickel-based superalloy particles account for 10% to 40% by weight of the mixture and the cobalt-based superalloy particles account for 60% to 90% by weight of the mixture.

8. The method according to any one of the preceding claims, wherein, The wear-resistant strip (30) contains nickel-based superalloy particles and cobalt-based superalloy particles with different relative contents.

9. The method according to any one of the preceding claims, wherein, The wear-resistant strip (30) has a gradient structure throughout its thickness direction.

10. The method according to claim 9, wherein, The wear-resistant strip is formed directly on the surface of the nickel-based alloy components to be bonded. The wear-resistant strip (30) comprises nickel-based superalloy particles with an internal content located at the interface (17) of the nickel-based alloy component (10), and nickel-based superalloy particles with an external content located opposite the interface, wherein the weight percentage of the internal content of the nickel-based superalloy particles is greater than that of the external content of the nickel-based superalloy particles; or, The wear-resistant strip (30) has an internal content of cobalt-based superalloy particles located on the surface (12) of the nickel-based alloy component (10), and an external content of cobalt-based superalloy particles located opposite the surface (12) of the nickel-based alloy component (10), wherein the weight percentage of the internal content of the cobalt-based superalloy particles is greater than that of the external content of the cobalt-based superalloy particles.

11. The method according to any one of the preceding claims, wherein, The nickel-based superalloy particles comprise a nickel-based superalloy comprising, by weight percentage: 50% to 55% nickel, 17% to 21% chromium, 4.75% to 5.50% niobium, 2.8% to 3.3% molybdenum, 0.65% to 1.15% titanium, 0.20% to 0.80% aluminum, up to 1.0% cobalt, and the balance being iron; and / or The cobalt-based superalloy particles contain a cobalt-based superalloy, which, by weight percentage, contains at least 55.5% cobalt, less than 0.08% carbon, 8% to 9% chromium, less than 1.5% iron, 27.5% to 31% molybdenum, less than 1.5% nickel, 2.5% to 3% silicon, and less than 1.0% other elements.

12. The method according to any one of the preceding claims, wherein, The average size of the nickel-based superalloy particles is 10µm to 40µm, and the average size of the cobalt-based superalloy particles is 10µm to 40µm.

13. The method according to any one of the preceding claims, wherein, The cobalt-based superalloy particles comprise a cobalt-based superalloy containing, by weight percentage, at least 55.5% cobalt, less than 0.08% carbon, 8% to 9% chromium, less than 1.5% iron, 27.5% to 31% molybdenum, less than 1.5% nickel, 2.5% to 3% silicon, and less than 1.0% other elements. The plurality of particles (24) are carried by a high-pressure gas flow heated to the spraying temperature, which is 500°C to 1100°C.

14. The method according to claim 1, wherein, The plurality of particles (24) are carried by a high-pressure airflow, which is heated to the spraying temperature, which is 500°C to 1100°C.

15. A nickel-based alloy component (10) formed by the method according to any one of the preceding claims.

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