An intermetallic compound-based thermal protection coating material and a preparation method thereof

Abstract

The application provides an intermetallic compound-based thermal protection coating material and a preparation method thereof, and belongs to the technical field of thermal spraying materials. The raw material of the intermetallic compound-based thermal protection coating material is 45-55% of Ni-based intermetallic compound powder, 38-48% of Al2O3 powder, 1-2% of Cr2O3 powder and 1-5% of a binder, according to the mass percentage. The Ni-based intermetallic compound powder comprises Cr 1-4%, Al 20-25%, Mo 0.2-1.0%, W 0.1-1.0%, Mn 0.1-0.5%, Co 0.2-1.0%, Ti 0.2-1.2%, and the balance is Ni and inevitable impurities, according to the mass percentage. The intermetallic compound-based thermal protection coating material provided by the application has uniform composition, good spraying adaptability and good melting effect, and a thermal protection coating with uniform structure, high bonding force and strong high-temperature thermal shock resistance is prepared by using a plasma spraying process.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of thermal spraying material, in particular to an intermetallic compound-based thermal protection coating material and a preparation method thereof. BACKGROUND

[0002] The hot end components of aircraft engines, gas turbines and other equipment need to withstand the corrosion and erosion of high-temperature fuel and high-pressure air mixture, and the ablation of high-temperature gas for a long time, so the heat resistance of the components is very important. Therefore, a high-temperature thermal protection coating needs to be coated on the surface of the hot end components.

[0003] The "nickel-based cermet" coating composed of nickel-based alloy as the skeleton component and alumina ceramic component has excellent performance and is widely used in the thermal protection coating of high-temperature hot end components. The nickel-based alloy powder and the ceramic powder are extruded into flexible wires by adding a rubber adhesive, and then a special flame spraying is used to prepare the thermal protection coating. The flexible wires are prone to moisture and deformation during storage and transportation, and are prone to breakage during transportation, handling and clamping during spraying. In addition, the wires are prone to breakage during spraying, and new wires need to be replaced continuously, resulting in discontinuous spraying process. The front end of the flexible wire needs to be cut and shaped before spraying, and the length of the wire is not enough when the rear end is sprayed, resulting in low utilization rate of the flexible wire and large material waste. The flexible wire will be secondary atomized under the action of flame, and the atomized particles are prone to insufficient melting, resulting in unstable deposition process, difficult control of coating quality, uneven organization, component segregation, inclusion of raw particles and other defects, and low bonding strength and poor high-temperature thermal shock resistance of the coating. SUMMARY

[0004] The present application aims to solve the problems of insufficient melting and discontinuous spraying of the existing flexible wires, resulting in uneven coating organization, component segregation, inclusion of raw particles and other defects. The present application provides an intermetallic compound-based thermal protection coating material and a preparation method thereof. The thermal protection coating material provided by the present application has uniform composition and strong spraying adaptability. The thermal protection coating prepared by plasma spraying has uniform organization, high bonding strength and strong high-temperature thermal shock resistance.

[0005] In order to achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0006] One of the technical solutions of the present application is an intermetallic compound-based thermal protection coating material, wherein the raw materials are 45-55% nickel intermetallic compound powder, 38-48% Al2O3 powder, 1-2% Cr2O3 powder and 1-5% binder, by mass percentage.

[0007] The Ni-based intermetallic compound powder comprises, by mass percentage, Cr 1-4%, Al 20-25%, Mo 0.2-1.0%, W 0.1-1.0%, Mn 0.1-0.5%, Co 0.2-1.0%, Ti 0.2-1.2%, with the balance being Ni and unavoidable impurities.

[0008] The second technical solution of the present invention is a method for preparing the above-mentioned intermetallic compound-based thermal protective coating material, wherein the Ni-based intermetallic compound powder is forcibly extruded and intercalated with Al2O3 and Cr2O3 powder to form a primary composite powder, then a binder is added to the primary composite powder, stirred, and then sieved.

[0009] The third technical solution of the present invention is the application of the above-mentioned intermetallic compound-based thermal protective coating material in the preparation of thermal protective coatings by plasma spraying.

[0010] The present invention discloses the following technical effects:

[0011] This invention uses β-NiAl-based intermetallic compounds as the metal skeleton component and prepares a thermal protective coating powder material through forced extrusion intercalation coating and agglomeration composite process. The coating powder material has uniform composition, good spraying adaptability and good melting effect. Using plasma spraying process, a thermal protective coating with uniform structure, high bonding force and strong resistance to high temperature thermal shock is prepared.

[0012] β-NiAl-based intermetallic compounds include Ni, Al, Cr, W, Co, Mo, and Mn as main elements, as well as trace elements such as Ti. These compounds ensure excellent high-temperature resistance of the coating. The exothermic reaction of NiAl significantly improves coating adhesion, while W enhances thermal shock resistance and Mn increases coating strength and hardness. Alumina and chromium oxide, with their high melting points and hardness, improve wear resistance and thermal shock resistance. The metal skeleton components in this coating exhibit good thermal expansion matching and a low potential difference with the high-temperature alloy matrix used in most equipment components, making the coating less susceptible to thermal stress and galvanic corrosion. Furthermore, the Cr element in the coating enhances corrosion resistance. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1The image shows the morphology of the Ni-based intermetallic compound powder prepared in step 2 of Example 1.

[0015] Figure 2 The image shows the microstructure of the primary composite powder prepared in step 3 of Example 1.

[0016] Figure 3 These are morphological photographs of the intermetallic compound-based thermal protective coating material prepared in Example 1;

[0017] Figure 4 The image shows the morphology of the coating obtained after plasma spraying the intermetallic compound-based thermal protective coating material prepared in Example 1.

[0018] Figure 5 The image shows the morphology of the flexible wire prepared in Comparative Example 1.

[0019] Figure 6 The image shows the morphology of the coating obtained after flame spraying the flexible wire prepared in Comparative Example 1.

[0020] Figure 7 The image shows the morphology of the coating obtained after plasma spraying the powdered thermal protective coating material prepared in Comparative Example 9.

[0021] Figure 8 This is a photograph showing the morphology of the coating obtained after plasma spraying the powdered thermal protective coating material prepared in Comparative Example 10. Detailed Implementation

[0022] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0023] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0024] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0025] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be obvious to those skilled in the art. This specification and embodiments are merely exemplary.

[0026] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0027] With the development of thermal spraying technology, powder is now the primary material used in thermal spraying. Thermal spray powder materials offer advantages such as high spraying adaptability, excellent melting and deposition effects, high utilization rate, and convenient and quick transportation and storage. Plasma spraying is currently a more advanced thermal spraying technology. The plasma flame reaches temperatures as high as 30,000℃ and particle flight velocities as high as 400m / s, generating sufficient energy to melt almost all powdered coating materials. It can spray various powder materials, including metal powders, ceramic powders, cermet powders, and composite powders, and can prepare various thermal protective coatings such as ablation-resistant coatings, thermal barrier coatings, and wear-resistant coatings. The plasma spraying process heats and accelerates the powder material, causing the powder particles to collide with the substrate, forming a dense, highly adhesive coating. Simultaneously, the equipment is highly automated, the process is stable, and the coating quality is consistent. The plasma spraying process for powder materials has good adaptability, and the resulting coatings exhibit high quality and stability.

[0028] The first aspect of the present invention provides an intermetallic compound-based thermal protective coating material, wherein the raw materials, by mass percentage, are 45-55% Ni-based intermetallic compound powder, 38-48% Al2O3 powder, 1-2% Cr2O3 powder and 1-5% binder;

[0029] The Ni-based intermetallic compound powder comprises, by mass percentage, Cr 1-4%, Al 20-25%, Mo 0.2-1.0%, W 0.1-1.0%, Mn 0.1-0.5%, Co 0.2-1.0%, Ti 0.2-1.2%, with the balance being Ni and unavoidable impurities.

[0030] In some embodiments of the present invention, the Ni-based intermetallic compound powder comprises, by mass percentage, Cr 1-3%, Al 20-23%, Mo 0.5-1.0%, W 0.3-0.8%, Mn 0.1-0.4%, Co 0.5-1.0%, Ti 0.5-1.0%, with the balance being Ni and unavoidable impurities.

[0031] In some embodiments of the present invention, the Ni-based intermetallic compound powder comprises, by mass percentage, 2-3% Cr, 20-21% Al, 0.5-0.7% Mo, 0.6-0.8% W, 0.2-0.4% Mn, 0.5-0.7% Co, and 0.5-0.7% Ti, with the balance being Ni and unavoidable impurities.

[0032] In some embodiments of the present invention, the Ni-based intermetallic compound powder comprises, by mass percentage, 2.0% Cr, 20% Al, 0.6% Mo, 0.5% W, 0.3% Mn, 0.6% Co, and 0.6% Ti, with the balance being Ni and unavoidable impurities.

[0033] In some embodiments of the present invention, the adhesive is at least one selected from polyvinylpyrrolidone, polyvinyl alcohol, epoxy resin, sodium carboxymethyl cellulose, and sodium metasilicate.

[0034] In some embodiments of the present invention, the particle size of the Ni-based intermetallic compound powder is less than or equal to 25 μm; the particle size of the Al2O3 and Cr2O3 powders is 5 to 50 μm.

[0035] In some embodiments of the present invention, the preparation method of the Ni-based intermetallic compound powder is as follows: after batching, the raw materials are smelted, and after the smelted alloy liquid is homogenized, it is atomized and sieved to obtain Ni-based intermetallic compound powder.

[0036] In some embodiments of the present invention, the atomization is inert gas atomization or atmospheric atomization.

[0037] A second aspect of this invention provides a method for preparing the aforementioned intermetallic compound-based thermal protective coating material. The method involves forcibly extruding and coating the Ni-based intermetallic compound powder with Al2O3 and Cr2O3 powders to form a primary composite powder. A binder is then added to the primary composite powder, and the mixture is stirred until the primary composite powder agglomerates into large particles. The powder is then sieved. The sieving process involves sequentially passing the powder through an 80-mesh sieve and a 325-mesh sieve.

[0038] This invention achieves the technical effect of uniform structure, high adhesion, high hardness, and strong resistance to high-temperature thermal shock in the obtained thermal protective coating by strictly controlling the composition of Ni-based intermetallic compound powder, its preparation method, the ratio of Ni-based intermetallic compound powder to Al2O3 and Cr2O3 powder, and the preparation method of intermetallic compound-based thermal protective coating material.

[0039] A third aspect of the present invention provides an application of the above-mentioned intermetallic compound-based thermal protective coating material in the preparation of thermal protective coatings by plasma spraying.

[0040] Unless otherwise specified, the technical solutions described in this invention are all conventional solutions in the field, and the reagents or raw materials used are all purchased from commercial channels or are publicly available unless otherwise specified.

[0041] To better understand the present invention, the following embodiments further illustrate the content of the present invention, but the content of the present invention is not limited to the following embodiments.

[0042] Example 1

[0043] An intermetallic compound-based thermal protective coating material is prepared using the following steps:

[0044] Step 1: Take nickel plate, chromium block, aluminum block, tungsten strip, manganese block, cobalt block, molybdenum block, and titanium plate and mix them together.

[0045] Step 2: In a fully inert gas protected hot gas atomizing furnace, the raw materials from Step 1 are added to the melting furnace. The melting power is 50kW. After the alloy liquid is homogenized, it is atomized using argon gas. The atomization parameters are: temperature 1600℃, atomization pressure 2.0MPa, atomization angle 60°, and nozzle diameter 5mm. Ni-based intermetallic compound powder is obtained (by mass percentage, the content of each element in the Ni-based intermetallic compound powder is: Cr 2.0%, Al 20%, Mo 0.6%, W 0.5%, Mn 0.3%, Co 0.6%, Ti 0.6%, with the balance being Ni and unavoidable impurities). Figure 1 The image shows a scanning electron microscope image of the powder, which is spherical.

[0046] Step 3: Measure 5.0 kg of Ni-based intermetallic compound powder, 4.56 kg of Al2O3 powder and 0.24 kg of Cr2O3 powder obtained in Step 2. Through the high-speed mechanical rotation of the extrusion head of the coating equipment, a strong extrusion pressure is generated to embed the Al2O3 powder and Cr2O3 powder into the surface of the intermetallic compound powder particles to obtain a primary composite powder. Figure 2 The image shows a scanning electron microscope image of a primary composite powder. The powder is spherical and coated with alumina powder.

[0047] Step 4: Measure 0.2 kg of polyvinylpyrrolidone, add 500 ml of deionized water, heat to 50°C to fully dissolve, and let stand at room temperature to obtain the adhesive.

[0048] Step 5: Pour the adhesive obtained in Step 4 into the primary composite powder obtained in Step 3, stir thoroughly and continue stirring until the powder becomes granular.

[0049] Step 6: Use an 80-mesh sieve and a 325-mesh sieve conforming to GB / T 5330-2003 to sieve the powder obtained in step 5 in sequence. The obtained powder is the final composite powder (intermetallic compound-based thermal protective coating material). Figure 3 A scanning electron microscope image of the final composite powder is shown.

[0050] The intermetallic compound-based thermal protective coating material prepared in this embodiment was subjected to plasma spraying. The plasma spraying parameters were: main gas flow rate 40-50 L / min, auxiliary gas flow rate 8-10 NLPM, carrier gas flow rate 3-6 NLPM, current 500-600 A, spraying power 35-40 kW, powder feed rate 10-20 g / min, spraying distance 80-120 mm, and gun feed rate 3-8 mm / s. During the plasma spraying process, the powder feed was smooth and uninterrupted, resulting in a uniform structure, significantly improved bonding strength, and enhanced thermal shock resistance of the prepared thermal protective coating. Figure 4 The image shows the microstructure of the plasma-sprayed coating. The adhesion strength of the plasma-sprayed coating is 35.6 MPa; the thermal shock resistance is 2200 cycles at 950℃; and the microhardness (HV0.2) of the coating is 630.

[0051] Comparative Example 1

[0052] Step 1: Same as Step 1 in Example 1.

[0053] Step 2: Same as Step 2 in Example 1.

[0054] Step 3: Measure 5.0 kg of Ni-based intermetallic compound powder and 4.8 kg of alumina ceramic powder obtained in Step 2, add 2 kg of silicone rubber, and extrude into flexible wires, such as... Figure 5 .

[0055] A thermal protective coating was prepared on the flexible wire of this comparative example using flame spraying. The coating structure was uneven and contained large particles. Figure 6 The coating has a bonding strength of 15.3 MPa, a thermal shock life of 800 cycles at 950℃, and a microhardness of 370 HV0.2.

[0056] Comparative Example 2

[0057] The only difference from Example 1 is that the W element in the Ni-based intermetallic compound powder is reduced from 0.5% to 0.05%, while the other steps and parameters are the same as in Example 1.

[0058] The intermetallic compound-based thermal protective coating material prepared in this embodiment was subjected to plasma spraying, with the same plasma spraying parameters as in Example 1. The plasma-sprayed coating had a thermal shock resistance life of 1800 cycles at 950°C (i.e., when the amount of W element is too low, the thermal shock resistance of the coating is significantly reduced).

[0059] Comparative Example 3

[0060] The only difference from Example 1 is that the W content in the Ni-based intermetallic compound powder is increased from 0.5% to 1.5%, while the other steps and parameters are the same as in Example 1.

[0061] The intermetallic compound-based thermal protective coating material prepared in this embodiment was subjected to plasma spraying, with the same plasma spraying parameters as in Example 1. The plasma-sprayed coating exhibited a thermal shock resistance lifetime of 2202 cycles at 950°C (i.e., when the amount of W element is too high, it has almost no effect on the thermal shock resistance of the coating, but the high melting point of W increases the difficulty of preparing Ni-based intermetallic compound powder and increases manufacturing costs).

[0062] Comparative Example 4

[0063] The only difference from Example 1 is that the Mn content in the Ni-based intermetallic compound powder is reduced from 0.3% to 0.05%, while the other steps and parameters are the same as in Example 1.

[0064] The intermetallic compound-based thermal protective coating material prepared in this embodiment was subjected to plasma spraying, with the same plasma spraying parameters as in Example 1. The adhesion strength of the plasma-sprayed coating was 31.2 MPa; the thermal shock resistance life at 950°C was 2120 cycles; and the microhardness HV0.2 of the coating was 510 (i.e., when the amount of Mn element is too low, the coating hardness, thermal shock resistance life, and adhesion strength decrease).

[0065] Comparative Example 5

[0066] The only difference from Example 1 is that the Mn content in the Ni-based intermetallic compound powder is increased from 0.3% to 1.5%. All other steps and parameters are the same as in Example 1.

[0067] The bonding strength of the plasma-sprayed coating is 35.8 MPa; the microhardness of the coating HV0.2 is 680; and the thermal shock life of the plasma-sprayed coating at 950℃ is 2205 cycles (i.e., when the amount of Mn element is too high, the coating hardness increases, but it has almost no effect on the bonding strength and thermal shock life, but it increases the manufacturing cost).

[0068] Comparative Example 6

[0069] The only difference from Example 1 is that the 5.0 kg of Ni-based intermetallic compound powder obtained in step 2 is replaced with 4.0 kg in step 3. All other steps and parameters are the same as in Example 1.

[0070] The intermetallic compound-based thermal protective coating material prepared in this embodiment was subjected to plasma spraying, with the same plasma spraying parameters as in Example 1. The increased ceramic component in the plasma-sprayed coating resulted in a coating bonding strength of 18.2 MPa and a thermal shock resistance of 2205 cycles at 950°C (i.e., reducing the proportion of nickel-based intermetallic compounds significantly reduces the coating bonding strength but slightly increases the thermal shock resistance).

[0071] Comparative Example 7

[0072] The only difference from Example 1 is that the 5.0 kg of Ni-based intermetallic compound powder obtained in step 2 is replaced with 6.0 kg in step 3. All other steps and parameters are the same as in Example 1.

[0073] The intermetallic compound-based thermal protective coating material prepared in this embodiment was subjected to plasma spraying, with the same plasma spraying parameters as in Example 1. The increased metal component in the plasma-sprayed coating resulted in a coating bond strength of 37.6 MPa and a thermal shock resistance of 2020 cycles at 950°C (i.e., increasing the proportion of nickel-based intermetallic compounds slightly improves the coating bond strength but reduces the thermal shock resistance).

[0074] Comparative Example 8

[0075] The only difference from Example 1 is that 5.0 kg of Ni-based intermetallic compound powder and 4.56 kg of Al2O3 powder obtained in step 2 are measured in step 3. All other steps and parameters are the same as in Example 1.

[0076] The intermetallic compound-based thermal protective coating material prepared in this embodiment was subjected to plasma spraying, with the same plasma spraying parameters as in Example 1. The increased metal content in the plasma-sprayed coating resulted in a coating bond strength of 36.2 MPa and a thermal shock life of 2006 cycles at 950°C (i.e., without the addition of chromium oxide, the coating bond strength is slightly improved, but the thermal shock life is reduced).

[0077] Comparative Example 9

[0078] Step 1. Take Ni powder, Cr powder, Al powder, Mo powder, W powder, Mn powder, Co powder, and Ti powder respectively according to the proportions of Cr 2.0%, Al 20%, Mo 0.6%, W 0.5%, Mn 0.3%, Co 0.6%, Ti 0.6%, with the balance being Ni (the particle size of Ni powder, Cr powder, Al powder, Mo powder, W powder, Mn powder, Co powder, and Ti powder is less than or equal to 25μm). The total mass of Ni powder, Cr powder, Al powder, Mo powder, W powder, Co powder, and Ti powder is 5.0kg. Mix it evenly with 4.56kg of Al2O3 powder and 0.24kg of Cr2O3 powder to obtain a mixed powder.

[0079] Step 2. Measure 0.2 kg of polyvinylpyrrolidone, add 500 ml of deionized water, heat to 50°C to fully dissolve, and let stand at room temperature to obtain the adhesive;

[0080] Step 3. Add the binder obtained in Step 2 to the mixed powder obtained in Step 1, stir thoroughly until the powder becomes granular. The final powder has extremely uneven composition, poor adaptability to plasma spraying (plasma spraying parameters are the same as in Example 1), a powder deposition rate of less than 5%, and a coating structure that is almost entirely composed of ceramic components. Figure 7 It has poor thermal expansion compatibility with the substrate, making it prone to cracking and chipping.

[0081] Comparative Example 10

[0082] Step 1. Same as Step 1 in Example 1;

[0083] Step 2. Same as step 2 in Example 1;

[0084] Step 3. Measure 0.2 kg of polyvinylpyrrolidone, add 500 ml of deionized water, heat to 50°C to fully dissolve, and let stand at room temperature to obtain the adhesive;

[0085] Step 4. Mix 5.0 kg of Ni-based intermetallic compound powder obtained in Step 2 with 4.56 kg of Al2O3 powder and 0.24 kg of Cr2O3 powder until homogeneous, then add the binder obtained in Step 3 and granulate. The final powder is then subjected to plasma spraying (plasma spraying parameters are the same as in Example 1), resulting in a decrease in the uniformity of the coating structure. Figure 8 The coating has a bonding strength of 25.5 MPa and a thermal shock life of 1890 cycles at 950℃.

[0086] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A thermal protective coating material based on intermetallic compounds, characterized in that, By mass percentage, the raw materials are 45-55% Ni-based intermetallic compound powder, 38-48% Al2O3 powder, 1-2% Cr2O3 powder and 1-5% binder; The Ni-based intermetallic compound powder comprises, by mass percentage, Cr 1-4%, Al 20-25%, Mo 0.2-1.0%, W 0.1-1.0%, Mn 0.1-0.5%, Co 0.2-1.0%, Ti 0.2-1.2%, with the balance being Ni and unavoidable impurities; The preparation method of the Ni-based intermetallic compound powder is as follows: after batching, the raw materials are smelted, and after the smelted alloy liquid is homogenized, it is atomized and sieved to obtain Ni-based intermetallic compound powder. The preparation method of the intermetallic compound-based thermal protective coating material is as follows: the Ni-based intermetallic compound powder is forcibly extruded and intercalated with Al2O3 and Cr2O3 powder to form a primary composite powder, then a binder is added to the primary composite powder, stirred, and then sieved.

2. The intermetallic compound-based thermal protective coating material according to claim 1, characterized in that, The adhesive is at least one of polyvinylpyrrolidone, polyvinyl alcohol, epoxy resin, sodium carboxymethyl cellulose, and sodium metasilicate.

3. The intermetallic compound-based thermal protective coating material according to claim 1, characterized in that, The particle size of the Ni-based intermetallic compound powder is less than or equal to 25 μm; the particle size of the Al2O3 and Cr2O3 powders is 5–50 μm.

4. The intermetallic compound-based thermal protective coating material according to claim 1, characterized in that, The atomization is either inert gas atomization or atmospheric atomization.

5. A method for preparing an intermetallic compound-based thermal protective coating material according to any one of claims 1-4, characterized in that, The Ni-based intermetallic compound powder is coated with Al2O3 and Cr2O3 powder by forced extrusion to form a primary composite powder. Then, a binder is added to the primary composite powder, the mixture is stirred, and then sieved.

6. The application of the intermetallic compound-based thermal protective coating material according to any one of claims 1-4 in the preparation of thermal protective coatings by plasma spraying.

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