Composite thermal spray powder of oxides and non-oxides

Abstract

Composite thermal spray powders are formed by producing two or more powder feedstock components with different chemical compositions, particle size ranges and morphologies, with these different characteristics resulting from different powder manufacturing processes. The resulting coatings typically function as an abradable seal, thermal barrier coating or environmental barrier coating, have improved temperature resistance and maintain favorable properties over a longer period of time compared to current coating materials. Thermal spray coatings can be formed by using the described composite powders consisting of two or more powder components with at least one of different powder fractions of particle size, morphology and / or chemical composition, or by co-spraying the described single components with at least different morphologies, such as agglomerated, agglomerated sintered, clad, fusion crushed, or hollow oven sphere powders.

Description

Technical Field

[0001] Cross - Reference to Related Applications This application claims the benefit and priority of U.S. Provisional Application No. 63 / 136,413, filed on January 12, 2021, the disclosure of which is hereby expressly incorporated by reference in its entirety.

[0002] Background 1. Field of the Disclosure Exemplary embodiments relate to the use of multiple powder fractions having different particle size ranges, morphologies, and chemical compositions resulting from several powder manufacturing methods. In particular, the exemplary embodiments relate to the spraying of a homogenized powder fraction having a chemistry suitable for the application of a coating exhibiting functionality that can range from thermal protection and / or environmental barrier protection and / or clearance control.

Background Art

[0003] 2. Background Information Coating morphology and chemical composition are relevant factors in thermal spray coating applications and relate to the starting characteristics of the powder feed material, such as its morphology, particle size distribution, and chemical properties. The relationship between the aforementioned powder characteristics and the resulting coating characteristics is used to design thermal spray coatings suitable for specific functions such as thermal shielding protection for turbomachinery, environmental barrier protection, and clearance control (abrasive) coatings. In the case of thermal spray abrasive coatings, they are widely used as clearance control technologies in aircraft engines and gas and steam turbines, for example, as seals to prevent undesirable gas backflow between the engine blade tips and the surrounding turbine casing. The use of sacrificial abrasive coatings for aircraft and stationary gas turbines is a means of increasing engine efficiency by reducing the tip clearance between rotor and stator components. A well-designed abrasive coating clearance control system not only improves engine efficiency but also increases the safety margin by allowing rotating components to rub against a surface that causes little to no damage to the components in the event of intrusion. In addition to their sealing function for thermal sprayed wear, these coatings can also provide additional functions such as thermal and / or environmental barrier protection, enabling stator components to withstand high-temperature environments by reducing the heat flux to the components (e.g., thermal barrier coatings) or by sealing the substrate from the ambient atmosphere (e.g., environmental barrier coatings). [Overview of the Initiative] [Means for solving the problem]

[0004] Summary of the Invention Exemplary embodiments relate to coatings applied by thermal spraying that present functions of thermal protection and / or environmental protection and / or clearance control in high-temperature environments, wherein the base material of the coating includes multiple ceramic powders of different compositions and / or particle size fractions and / or morphologies resulting from different powder manufacturing methods. Abrasive coatings applied to the shroud sections of aircraft engines and land-based turbines help seal the clearance between the rotating blades / fins and the surrounding engine stator structure. Sealing the clearance contributes to minimizing the leak gap by sacrificing the abrasive coating to protect the blades, thereby increasing engine efficiency and life. Higher operating temperatures for gas turbine engines are constantly required to increase efficiency. However, as operating temperatures rise, the high-temperature durability of the engine components must also increase accordingly. At such high temperatures, ceramic-based thermal spray abrasive coatings tend to sinter, resulting in an increase in hardness beyond an unacceptable level, making blade damage more likely in the event of friction events. The disclosed invention describes the use of multiple powder fractions with different particle size ranges and morphologies resulting from several powder manufacturing methods and compositions. The proposed combinations of different particle morphologies and size ranges were found to produce coatings exhibiting good abrasion resistance, sufficient resistance to solid particle erosion, and excellent resistance to sintering with little to no age hardening.

[0005] Thermal barrier coatings (TBCs) are applied to components such as combustors, high-pressure turbine blades, vanes, and shrouds. By applying TBCs, the operating temperature of high-temperature gas path components can be increased, resulting in higher energy output and improved engine efficiency. The insulation provided by TBCs allows TBC-coated components to survive at higher operating temperatures, increasing component durability and improving engine reliability. Significant advances in high-temperature performance have been achieved, and conventional yttria-stabilized zirconia (YSZ) can be used for TBC-based insulation. Coating with 6-8 weight percent yttria added to zirconia provides the desired thermal shock resistance due to a toughening mechanism at the leading edge of cracks that grow as a result of a phase transformation from tetragonal to monoclinic under stress. A key advantage of YSZ is that it is also more elastically flexible, resulting in a lower Young's modulus (E). Increasing the use of up to 90 weight percent rare earth elements for rare-earth-stabilized zirconia coatings results in a decrease in thermal conductivity, avoiding phase transformation of the coating, and the coating is fully stabilized in its cubic crystalline form. Powder materials processed by thermal spraying technology to form coatings are manufactured in various ways. The goal in producing such powder materials is to obtain good fluidity, low or no deviation in composition, reproducibility, and ease of manufacture. The morphology of the resulting powder varies depending on the manufacturing process used to produce the powder, thereby resulting in different coating microstructures and properties. Various types of powders may be used. For example, aggl., agglomerated and sintered (A&S), hollow oven-spherical powder (HOSP), chemically or physically clad (Clad), and fusing and crushed (F&C) powders are typical powder manufacturing processes that result in unique particle morphologies. It has been found that using multiple powder fractions with different particle size ranges and morphologies resulting from these different powder manufacturing methods produces coatings with unique properties.

[0006] When using a fused crushed powder structure, a higher density coating structure can be achieved, increasing adhesive strength and Young's modulus, thereby improving the coating's resistance to solid particle erosion. Agglomerated sintered powder is manufactured from fine primary particles, allowing for better control of the chemical composition of individual particles and agglomeration. Agglomerated sintered powder is used to provide a desired balance of porosity and erosion resistance, as well as efficient deposition efficiency. Larger aggregates are embedded in coatings made from agglomerated sintered powder, which increases the porosity required for applications with lower thermal conductivity. Using agglomerated particles with coarse particle size generates a large porosity in the microstructure from the spraying process, leaving the particles unmelted, but the combination of coarse particle size and the easy fracture of the powder tends to reduce spray deposition efficiency. Advantages of having agglomerated powder as a feedstock include a coating microstructure that decomposes with less energy from severance due to looser bonding between particles. However, this can negatively impact the coating's erosion resistance. Cladding powders can be prepared by known mechanical and / or chemical cladding processes. The powder material may consist solely of a flux material to facilitate bonding, or, in embodiments where a functional layer of cladding material is desired, the powder material may be a separate layer placed beneath the layer of powder flux material, or may include powder mixed with the powder flux material, or powder combined with the flux material in composite particles, with a layer of cladding material formed on the surface by melting. Thus, optimizing the cladding structure can produce a coating that has higher durability and provides excellent thermal insulation over long periods of use by having gaps between randomly distributed columns and nodules within the microstructure.

[0007] Exemplary embodiments relate to a powder having a bimodal particle size distribution combined with two or more powder forms to produce a coating having a better balance of hardness, thermal fatigue resistance, thermal shock resistance, erosion resistance, and sintering resistance, and to enable good wear performance over the entire lifespan of a turbine component. The resulting product may comprise two or more powders or components or forms, also referred to herein as components. The primary component may be a matrix-forming agent, and the secondary component(s) may be a porosity-forming agent or structural hardening agent added to customize and optimize the coating obtained for a given application.

[0008] Ceramic wear-resistant coatings offer the advantage of improving the cutting performance of high-temperature parts of turbine engines. While ceramics are advantageous due to their resistance to temperatures exceeding 1000°C, the generally higher hardness of these materials can also lead to wear damage to turbine blades, for example, nickel superalloy-based turbine blades (aerospace engines or gas turbine sections). The composite powders of the disclosed invention utilize different particle morphologies resulting from different manufacturing techniques that can improve the coating properties with respect to wear, and these properties can be maintained over the service life of the coating. In addition to the composite powders, intensive mixing of dislocators or transient phases selected from the group consisting of polymers (e.g., polyester, PMMA, polyimide, ...), solid lubricants (e.g., hexagonal boron nitride, calcium fluoride, graphite, ...), and / or alternative filler phases (e.g., clay, magnesium silicate, aluminum silicate, ...) can further improve the coating properties with respect to wear by providing the necessary porosity in the coating matrix.

[0009] Inefficient cutting processes can lead to severe wear damage, and under harsh frictional contact conditions within the turbine, and / or if the thermally sprayed wear-resistant coating is too hard, it can result in excessive frictional heating of the blade material. Examples of blade damage mechanisms include bulk plastic deformation and fracture, oxidation of the material resulting from frictional heating, and cracking of the material due to extreme cutting forces.

[0010] Thermal barrier coatings (TBCs) can improve the thermal insulation and corrosion resistance properties of coated components and maintain these properties over the service life of the components by reducing sintering through the use of ceramics containing composite powders. The composite powders of the present invention have different particle morphologies, chemical compositions, and / or particle size distributions due to different powder manufacturing routes. As an example, turbine blades and other components of turbine engines may be composed of nickel-based superalloys with thermal barrier coatings, as they need to maintain their integrity at operating temperatures of at least 1000°C to 1150°C. The thermal barrier coating, in combination with an MCrAlY bond coat, provides greater resistance to corrosion and oxidation in these high-temperature environments compared to the underlying alloy itself.

[0011] Environmental barrier coatings (EBCs) improve the protection of engine components from the effects of environmental threats such as high-temperature gases, water vapor, and oxygen. For example, engine components can be manufactured from ceramic matrix composites, and EBCs can be applied to gas turbine components composed of ceramic matrix composites (CMCs) such as SiC-SiC composites.

[0012] An exemplary embodiment includes an improved thermal spray powder useful for clearance control applications in gas turbine engines, enabling engine components to survive in high-temperature environments such as the harsh thermal environment of a gas turbine engine (i.e., above 1000°C). The exemplary embodiment includes a powder material for producing a coating applied by thermal spraying, the powder material having improved mechanical properties such as abrasion resistance, adhesive strength, and Young's modulus, as well as thermal properties such as thermal conductivity, thermal shock resistance, and sintering resistance. The exemplary embodiment provides these properties along with high deposition efficiency, which may require maintaining a balance between porosity level, hardness, and resulting corrosion resistance.

[0013] Exemplary embodiments provide improved powders prepared by homogenizing two or more powder components having different particle morphologies due to different manufacturing methods. Each component may also have a different particle size distribution and chemical composition. For example, ceramic compositions, such as various types of any single component aluminum oxide (Al2O3), barium strontium aluminosilicate (BSAS; 1-xBaO-xSrO-Al2O3-2SiO2), calcium oxide (CaO), hafnium oxide (HfO2), high-entropy oxides (HEO), magnesium oxide (MgO), aluminosilicates or mullite (Al2O3-SiO2), silicon dioxide (SiO2). 2-x ) and zirconium oxide (ZrO2) may contain rare earth (RE) oxides ranging from 0 (>0) weight percent to 90 weight percent. RE represents oxides of Ce, Dy, Er, Eu, Gd, Hf, Ho, La, Nd, Lu, Pm, Pr, Sc, Sm, Tb, Tm, Y, Yb, or combinations thereof.

[0014] High-entropy oxides (HEOs) are oxides having high configuration entropy S(config). They typically contain five or more different metal cation types and oxygen to form one or more oxide sublattices. International Publication 2020 / 142125A2 to He et al., whose entire disclosure is incorporated herein by reference, discloses compositions of high-entropy oxides (HEOs). At least five of the different oxide-forming metal cations are: a) transition metals: at least one of Sc, Y, Ti, Zr, V, Nb, Ta, Cr, Mo, W, Mn, Re, Fe, Ru, Co, Ni, Cu, or Zn, and / or lanthanides La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb 、 It contains at least one of Dy, Ho, Er, Yb, or Lu. One of at least five different oxide-forming metal cations may also contain at least one of the alkaline earth metals: Be, Mg, Ca, Sr, or Ba. High entropy is defined by having 3, 4, or 5 or more major elements, and the content of major elements may be 5 to 35 weight percent.

[0015] Each component may have different forms, such as cylindrical, flakey, irregular, plate-like, spherical, or spherical hollow, resulting from various manufacturing methods, e.g., agglomerated, agglomerated and sintered, chemically or physically clad, fused and crushed, and / or hollow oxide spherical powder (HOSP), etc., having a porous or high-density structure. The method according to an exemplary embodiment includes providing these components in a form that allows for limited or no polymer binders for optimal coating, and forming the resulting powder for producing a thermal spray coating having properties such as hardness, porosity level, and erosion resistance that are maintained even after exposure to high temperatures of 1000°C or higher.

[0016] Exemplary embodiments improve the functionality of component-based thermal spray coatings for higher operating temperature applications, for example, in the range of 1000°C or above, by intensively mixing or simultaneously spraying multiple powders. As an example, abrasion seals are used in turbomachinery to reduce the clearance between rotor and stator components. Reducing the clearance can improve the efficiency of the turbine engine and reduce fuel consumption by reducing or eliminating the possibility of catastrophic blade / engine case contact friction. Clearance control seals are manufactured by applying an abrasion coating to the fixed parts of the engine in such a way that the rotating parts rub against the abrasion coating.

[0017] Exemplary embodiments include compositions, powder structures, and powder manufacturing methods for developing a new generation of ceramic materials for high-temperature applications and improved coating performance compared to powder materials including single-type forms. One example of an application is the minimum temperature and functional stability required for a new generation of engines in the aerospace industry, which is in the range of 1000°C or higher.

[0018] Exemplary embodiments include ceramic-based thermal spray powders for producing wear-resistant coatings for clearance control applications where rotating parts within an engine may come into contact with the coating as a result of design intent or operating requirements. These coatings are designed to minimize wear on rotating parts while maximizing gas path efficiency by providing clearance control in sealing areas. Such coatings combine the desired properties of a soft, sinter-resistant material through the production of an agglomerated powder component combined with a fusion-crushed powder component having a high rare-earth oxide content in the matrix. Another example of a coating may combine the agglomerated powder component with an agglomerated sintered powder component that exhibits a coating structure showing an appropriate balance between key functions such as its cutting performance, its temperature resistance and its erosion resistance.

[0019] The embodiment relates to a method for producing thermal spray powder. The method includes preparing a plurality of powders, each having at least one of different composition ratios or different forms, and combining two or more of the plurality of powders to form a composite powder.

[0020] In the embodiment, the combined two or more powders comprise a material selected from the group consisting of a combination of at least one main component and one or more secondary components. The combined two or more powders, having at least different particle ranges or different chemical compositions, are intensively mixed with a dislocator or transient phase selected from, but not limited to, the group consisting of polymers, boron nitride, bentonite, talc, calcium fluoride, or graphite. Furthermore, the combined two or more powders further comprise at least one dislocator or transient phase selected from the group consisting of polyester, boron nitride, or graphite.

[0021] According to the embodiment, at least one of two or more powders comprises at least one ceramic composite selected from the group consisting of aluminum oxide, barium strontium aluminosilicate, calcium oxide, hafnium oxide, high-entropy oxides, magnesium oxide, mullite, silicon oxide, and zirconium oxide. Furthermore, the high-entropy oxide may include a matrix having at least three major elements, each constituting 5 to 35 weight percent of the matrix. The at least one ceramic may include rare earth oxides selected from the group consisting of Ce, Dy, Er, Eu, Gd, Hf, Ho, La, Nd, Lu, Pm, Pr, Sc, Sm, Tb, Tm, Y, Yb, and mixtures thereof. Furthermore, the at least one ceramic composite consists of particles ranging from 10 μm to 180 μm.

[0022] In other embodiments, the thermal spraying can include a powder porosity ranging from about 1% to about 90%.

[0023] In the embodiment, two or more powders have at least one of different particle ranges, different forms, or different chemical compositions, and the combination involves intensively mixing the two or more powders with a dislocator or transient phase selected from the group consisting of polymers, boron nitride, bentonite, talc, calcium fluoride, or graphite.

[0024] Embodiments relate to a method for forming an abrasive coating layer. The method includes at least one of the following: forming an abrasive coating layer on a substrate by thermal spraying a mixture of a plurality of powders or by simultaneously spraying a plurality of powders at a temperature sufficient to partially melt the particles of the powder supply material during thermal spraying; and cooling the abrasive coating layer to room temperature such that the abrasive coating layer is substantially crack-free. The plurality of powders include two powders having different forms.

[0025] According to an embodiment, the thermal spraying may include at least one selected from the group consisting of air plasma spraying, high-velocity oxy-fuel spraying, or combustion spraying.

[0026] In still other embodiments, the plurality of powders have at least one of different particle ranges or different chemical compositions.

[0027] An embodiment relates to a method of forming a wear-resistant coating. The method includes spraying a powder-based coating onto a substrate, the sprayed coating having a thickness of about 5 μm to 8,000 μm, and the powder including rare earth elements constituting more than 0 weight percent to 90 weight percent of the sprayed coating.

[0028] The present disclosure will be further described in the following detailed description with reference to the plurality of drawings mentioned as non-limiting examples of the preferred embodiments of the present disclosure, and throughout several views of the drawings, like numerals represent like elements.

Brief Description of the Drawings

[0029] [Figure 1] FIG. 1 shows combinations of powders having different morphologies resulting from several manufacturing methods according to the exemplary embodiment mentioned. [Figure 2] FIG. 2 shows a coating microstructure including agglomerated particles and fused and crushed particles according to the exemplary embodiment mentioned. [Figure 3] FIG. 3 is a diagram showing a coating microstructure including agglomerated particles and HOSP particles according to the above-described exemplary embodiment. [Figure 4] FIG. 4 is a diagram showing a coating microstructure including agglomerated particles and agglomerated and sintered particles according to the above-described exemplary embodiment. [Figure 5] FIG. 5 is a diagram showing a coating microstructure including agglomerated particles and mechanically or chemically clad particles according to the above-described exemplary embodiment. [Figure 6] FIG. 6 shows selective microstructures and mechanical properties of as-sprayed coatings according to various exemplary embodiments. [Modes for carrying out the invention]

[0030] Detailed explanation Through one or more of the various aspects, embodiments, and / or specific features of this disclosure, it is intended to draw upon one or more of the advantages defined in the sections describing the invention.

[0031] In exemplary embodiments, the sprayable powder may have a size of 5 μm to 180 μm, and each powder particle essentially consists of i) 0 (>0) to 90 weight percent yttria (or other specific rare earth oxides) and the remainder zirconia, ii) >0 to 90 weight percent ytterbia (or other specific rare earth oxides) and the remainder silicate, or iii) a high-entropy oxide matrix containing at least three main oxides, each comprising 5 to 35 weight percent of the matrix, and unavoidable impurities (less than 1%).

[0032] In exemplary embodiments, powder particles consisting essentially of specific rare earth oxides can be used instead of the yttria or ytterbia powder particles described above. In such powder particles, the amount of rare earth oxide may be >0% to 90% by weight. The rare earth oxides may include Ce, Dy, Er, Eu, Gd, Hf, Ho, La, Nd, Lu, Pm, Pr, Sc, Sm, Tb, Tm, Y, and Yb, as well as any combination thereof.

[0033] In the embodiment, multiple powders may be used, and each powder may have different forms resulting from various manufacturing methods, such as cylindrical, flake, irregular, plate-like, spherical, or spherical hollow powders having a porous or high-density structure, and for example, agglomerated, agglomerated sintered, chemically or physically clad, or fused-crushed hollow oxide spherical powders.

[0034] Figure 1 shows powders blended with various other types of powders according to various exemplary embodiments. Figure 1 shows several combinations of components. As a first example, the first component may be agglomerated particles produced using a second component, which are fused and crushed (F&C) particles. A second example includes a first component of agglomerated particles and a second component of hollow oxide spherical particles (HOSP). A third example includes a first component of agglomerated and sintered (A&S) particles and a second component of agglomerated particles. A fourth example includes a first component of agglomerated and sintered (A&S) particles and a second component of mechanically or chemically clad particles. Naturally, the above combinations are merely examples, and any other combination of agglomerated F&C, HOSP, A&S and mechanically or chemically clad particles may be used as the first component and any other combination of agglomerated F&C, HOSP, A&S and mechanically or chemically clad particles as the second component without departing from the spirit and scope of the embodiments.

[0035] Figure 2 shows coating structures consisting of agglomerated particles combined with fused and crushed particles according to various exemplary embodiments. The fused and crushed particles are formed from fused solid masses and then crushed to the appropriate size. The fusion and crushing techniques produce powders with matched size, shape, chemical properties, and toughness. In exemplary embodiments, the composite powder comprises a first component consisting of agglomerated particles and a second component consisting of F&C particles. In the exemplary embodiments shown in Figure 2, some particles remain unmelted, and the shape of the resulting particles is altered by local stress, but includes a quantity of thick splats resulting from the F&C powder formation process.

[0036] Figure 3 shows coating structures comprising aggregated particles and HOSP particles according to various exemplary embodiments. In the exemplary embodiments, the composite powder mixture comprises a first component of aggregated particles and a second component of HOSP particles. In this example, the HOSP component can be considered a porosity-forming agent, and the aggregated component acts as a matrix.

[0037] Figure 4 shows coating structures comprising aggregated particles and aggregated sintered particles according to various exemplary embodiments. In exemplary embodiments, the composite powder comprises a first component of aggregated particles and a second component of A&S particles. In this example, the A&S component can be considered a porosity-forming agent, and the aggregated component acts as a matrix.

[0038] Figure 5 shows coating structures comprising aggregated particles and mechanically or chemically clad particles according to various exemplary embodiments. In the exemplary embodiments, the composite powder comprises a first component of aggregated particles and a second component of mechanically or chemically clad particles. In this example, the mechanically or chemically clad component can be considered a porosity-forming agent, and the aggregated component acts as a matrix.

[0039] Table 1 below includes examples of possible combinations in embodiments containing two or more components.

[0040] [Table 1]

[0041] Table 2 below discloses a typical powder chemistry of the target according to exemplary embodiments: Rare earth oxides (RE) represent oxides of Ce, Dy, Er, Eu, Gd, Hf, Ho, La, Nd, Lu, Pm, Pr, Sc, Sm, Tb, Tm, Y, Yb, or combinations thereof.

[0042] [Table 2]

[0043] In exemplary embodiments, a method for producing spray-dried agglomerated powder involves preparing fine particles (average particle size less than about 10 μm) of alumina, BSAS, CaO, hafnia, HEO, MgO, mullite, silica, and / or zirconia by mixing fine particles with an organic binder and a suspension agent in water to form a slurry. The slurry is then spray-dried to produce agglomerated particles, which can then be applied using various thermal spraying techniques to coat engine parts. The agglomerates do not need to be substantially brittle so as not to decompose during particle blending, handling, and / or feeding. In exemplary embodiments, spherical agglomerates exhibit a low surface area, which, when combined with other powder feed components having different forms, reduces friction, improves fluidity, and lowers viscosity.

[0044] Using separate alumina, BSAS, CaO, hafnia, HEO, MgO, mullite, silica, and / or zirconia raw materials can result in chemical heterogeneity of powder particles. To achieve phase stability, the final coating may contain alloys of separate alumina, BSAS, CaO, hafnia, HEO, MgO, mullite, silica, and / or zirconia. In the case of spray-dried powders, alloying can be performed during the powder manufacturing process or during the thermal spraying process. The need to alloy the powder during thermal spraying can be reduced or eliminated by performing the alloying step before thermal spraying. Conventional techniques rely on plasma densification or sintering of spray-dried powders. The sintering process hardens and strengthens the powder as individual primary particles grow to form an interconnected network. The interconnectivity of the resulting sintered body results in increased density and cohesive strength. Agglomerated powder particles and agglomerated sintered powder particles are typically substantially spherical in shape and have a finely distributed internal particle porosity.

[0045] In exemplary embodiments, spray-dried powders prepared from pre-alloyed alumina, BSAS, CaO, hafnia, HEO, MgO, mullite, silica, and / or zirconia starting materials produce substantially uniform powders despite variations that may occur during slurry preparation or the spray-drying process, and even when a wide particle size distribution is used as the starting material for preparing the powder. In exemplary embodiments, the powder may not be alloyed before or during thermal spraying. One such plasma-densified powder is currently available as HOSP. Such pretreatment eliminates alloying variations caused by inconsistent treatment of particles during the thermal spraying process. Pretreatment can also result in a more structurally stable powder that reduces powder fracture before thermal spraying and can prevent proper alloying of the powder during spraying. Furthermore, the particles are converted into hollow spheres that create large pores in the resulting coating structure.

[0046] As an alternative to spray-dried and pre-treated powders, fused and crushed powders have been used in the field of thermal spraying for TBC applications. For example, individual yttria and zirconia powders are mixed and fused using induction arc or other processes to produce briquettes of the fused material. The briquettes are then crushed to produce powders of the desired size, generally 11 μm to 150 μm, suitable for thermal spraying. F&C powders may exhibit angular and irregular morphologies. As a result, the use of these powders can lead to inconsistent powder supply. Furthermore, powder particles are generally denser and less meltable, resulting in reduced deposition efficiency due to insufficient heating of the particles during thermal spraying. The resulting coatings may have lower porosity compared to coatings made from powders with internal porosity, such as agglomerated powders, agglomerated and sintered powders, and HOSP.

[0047] Figure 6 shows the selective microstructure and mechanical properties of as-sprayed coatings according to various exemplary embodiments. Figure 6 shows various combinations of the first and second components from any one of the following five types of powder forms described: HOSP, A&S particles, aggregated particles, chemically or physically clad particles, and F&C particles. Furthermore, Figure 6 shows exemplary formulation ratios, as well as exemplary mean hardness range (AHV) (unit: HR 15N) and exemplary mean erosion resistance range (AEV) (unit: s / mil).

[0048] As shown in Figure 6, the first component can be >0 to 90 wt% (RE)SZ, and the second component can be >0 to 90 wt% (RE)SZ. Furthermore, the RE oxide of the first component may be the same as or different from the RE oxide of the second component. The first component may have a preferred chemical range of 5 to 60 (RE)SZ, 15 to 25 (RE)SZ, 45 to 55 (RE)SZ, or 5 to 15 (RE)SZ, and the second component may have a preferred chemical range of 5 to 60 (RE)SZ, 15 to 25 (RE)SZ, 45 to 55 (RE)SZ, or 5 to 15 (RE)SZ. It should also be noted that the chemistry of the first and second components may be the same or different. Exemplary RE oxides and / or chemistry of the first and second components are shown in Exemplary Table 3.

[0049] [Table 3]

[0050] Table 3 shows some chemical ranges depending on the RE oxide used, but this exemplary enumeration is, of course, not exhaustive to include all possible combinations of various RE oxides and / or chemical properties of the first and second components according to the embodiment.

[0051] In exemplary embodiments, there are several exemplary methods by which the material can be applied to a substrate. In one exemplary embodiment, the powder feed material may consist of two or more components that are sprayed onto a substrate such as an engine shroud or blade. In another embodiment, the powder feed material consisting of two or more components can be simultaneously sprayed, i.e., applied, onto a substrate such as an engine shroud or blade. During the "simultaneous spraying" process, the two powder components are applied simultaneously and separately.

[0052] As a non-limiting example, the above-mentioned powders are manufactured from multiple components having different forms, size ranges, and compositions. The above-mentioned abrasive powders are, for example, applied to a layer of AMDRY995C or AMDRY962 bond coat on HASTELLOY X as a substrate. each deposited , form a coupon All bond coats are preferably 100 μm to 200 μm thick, and the coating is sprayed to a maximum total coating thickness of 2.0 mm. For each powder type... , spout Hardness, metallography, erosion, and abrasion properties in the misted state and after exposure to 1000°C in the air for 24 hours. To make a decision, the coupon preparation It will be done Different tests performed on the coatings compared to commercially available coating products demonstrate that such experimental powder compositions can produce coatings with substantially improved properties compared to benchmarked legacy products. Hardness and corrosion resistance could be matched to the desired operating window in the as-sprayed state, and the effects of sintering were eliminated.

[0053] The examples of embodiments described herein are intended to provide a general understanding of various embodiments. The examples are not intended to serve as a complete description of the elements and features of all devices and systems utilizing the structures or methods described herein. Many other embodiments will be apparent to those skilled in the art upon consideration of this disclosure. Other embodiments can be utilized and derived from this disclosure so as to allow for structural and logical substitutions and modifications without departing from the scope of this disclosure. Furthermore, the figures are merely representative and may not be drawn to scale. Certain proportions in the examples may be exaggerated, while other proportions may be minimized. Therefore, this disclosure and the drawings should be considered illustrative, not restrictive.

[0054] One or more embodiments of this disclosure may be referred to herein individually and / or collectively by the term “invention” for convenience only and without the intention of voluntarily limiting the scope of this application to any particular invention or inventive concept. Furthermore, while certain embodiments are illustrated and described herein, it should be understood that any subsequent configuration designed to achieve the same or similar objectives may be used instead of the specific embodiments shown. This disclosure is intended to cover all possible subsequent adaptations or variations of various embodiments. Combinations of the embodiments described herein, and other embodiments not specifically described herein, will be apparent to those skilled in the art upon consideration of the description.

[0055] This abstract of the disclosure is submitted with the understanding that it is not to be used to interpret or limit the claims or their meaning. Furthermore, in the preceding detailed description, various features may be grouped together or described in a single embodiment for the purpose of simplifying the disclosure. The disclosure should not be construed as reflecting an intention that the claimed embodiments require more features than expressly described in each claim. Rather, as reflected in the following claims, the subject matter of the invention may cover fewer features than all of any of the disclosed embodiments. Accordingly, the following claims are incorporated into the detailed description, and each claim stands independently as defining separately claimed subject matter.

[0056] The subject matter disclosed above should be considered illustrative rather than restrictive, and the attached claims are intended to cover all such modifications, enhancements, and other embodiments that fall within the true intent and scope of this disclosure. Therefore, to the maximum extent permitted by law, the scope of this disclosure should be determined by the broadest permissible interpretation of the following claims and their equivalents, and should not be limited or restricted by the foregoing detailed description.

Claims

1. A method for producing thermal spray powder, wherein the method is The preparation of multiple types of powders, wherein each of the multiple types of powders has a different form from the others. The process involves combining the aforementioned multiple types of powders to form a composite powder, Includes, The composite powder comprises a first component and a second component, wherein the content of the first component is 50% to 90% by weight of the composite powder, and the content of the second component is 10% to 50% by weight of the composite powder. The first component and the second component have the aforementioned different forms, The above-mentioned form is selected from the group consisting of fused and crushed (F&C) particles, aggregated particles, aggregated and sintered (A&S) particles, mechanically or chemically clad particles, and hollow oxide spherical particles (HOSP). The first and second components are (RE)Al 2 O 3 , (RE)BSAS, (RE)CaO, (RE)HEO, (RE)HfO, (RE)MgO, (RE)mullite, (RE)SiO x , and (RE)ZrO 2 Selected from the group consisting of, where BSAS represents barium strontium aluminosilicate, and HEO represents a high-entropy oxide, The above (RE) represents an oxide of Ce, Dy, Er, Eu, Gd, Hf, Ho, La, Nd, Lu, Pm, Pr, Sc, Sm, Tb, Tm, Y, Yb, or a combination thereof, in a method.

2. The method according to claim 1, wherein the plurality of types of powders are prepared using different manufacturing processes.

3. The aforementioned multiple types of powders have at least different particle sizes or different chemical compositions. The method according to claim 1, further comprising mixing the plurality of types of powders with at least one selected from the group consisting of polymers, boron nitride, bentonite, talc, calcium fluoride, or graphite.

4. The method according to claim 3, wherein the polymer includes polyester.

5. The method according to claim 1, wherein the high-entropy oxide comprises a matrix having at least three main elements, each constituting 5 to 35 weight percent of the matrix.

6. The method according to claim 5, wherein the composite powder consists of particles ranging from 10 μm to 180 μm in size.

7. The method according to claim 1, wherein the thermal spray powder contains a powder porosity in the range of 1% to 90%.

8. The method according to claim 1, wherein the plurality of types of powders have different particle sizes.

9. A method for forming a coating layer, wherein the method is A mixture of several types of powders is sprayed, or By simultaneously spraying the aforementioned multiple types of powders, Forming the coating layer on the substrate at a temperature sufficient to partially melt the particles of the powder supply material during thermal spraying, and Cooling the coating layer to room temperature, wherein the coating layer is free from cracks, It includes at least one of the following: The aforementioned plurality of powders include two powders having different forms, The aforementioned plurality of types of powders comprises a first component and a second component, wherein the content of the first component is 50% to 90% by weight of the plurality of types of powders, and the content of the second component is 10% to 50% by weight of the plurality of types of powders. The first component and the second component have the aforementioned different forms, The above-mentioned form is selected from the group consisting of fused and crushed (F&C) particles, aggregated particles, aggregated and sintered (A&S) particles, mechanically or chemically clad particles, and hollow oxide spherical particles (HOSP). The first and second components are (RE)Al 2 O 3 , (RE)BSAS, (RE)CaO, (RE)HEO, (RE)HfO, (RE)MgO, (RE)mullite, (RE)SiO x , and (RE)ZrO 2 Selected from the group consisting of, where BSAS represents barium strontium aluminosilicate, and HEO represents a high-entropy oxide, The above (RE) represents an oxide of Ce, Dy, Er, Eu, Gd, Hf, Ho, La, Nd, Lu, Pm, Pr, Sc, Sm, Tb, Tm, Y, Yb, or a combination thereof, in a method.

10. The method according to claim 9, wherein the thermal spraying includes at least one selected from the group consisting of air plasma spraying, high-velocity flame spraying, or combustion spraying.

11. The method according to claim 9, wherein the plurality of types of powders have at least one of different particle ranges or different chemical compositions.

12. A method for forming a thermal spray coating, wherein the method is This includes thermal spraying a powder-based coating onto a substrate. The thermal spray coating has a thickness of 5 μm to 8,000 μm, and the powder contains rare earth elements that constitute more than 0 weight percent to 90 weight percent of the thermal spray coating. The powder comprises a first component and a second component, wherein the content of the first component is 50% to 90% by weight of the powder, and the content of the second component is 10% to 50% by weight of the powder. The first component and the second component have different forms from each other. The above-mentioned form is selected from the group consisting of fused and crushed (F&C) particles, aggregated particles, aggregated and sintered (A&S) particles, mechanically or chemically clad particles, and hollow oxide spherical particles (HOSP). The first component and the second component are (RE)Al 2 O 3 , (RE)BSAS, (RE)CaO, (RE)HEO, (RE)HfO, (RE)MgO, (RE)mullite, (RE)SiO x , and (RE)ZrO 2 selected from the group consisting of, wherein the BSAS represents barium strontium aluminosilicate, and the HEO represents a high entropy oxide The above (RE) represents an oxide of Ce, Dy, Er, Eu, Gd, Hf, Ho, La, Nd, Lu, Pm, Pr, Sc, Sm, Tb, Tm, Y, Yb, or a combination thereof, in a method.

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