Multi-component sealing coating powder material and preparation method thereof

Abstract

The invention provides a multi-component sealing coating powder material and a preparation method thereof, and belongs to the technical field of thermal spraying materials. The multi-component sealing coating powder material is prepared from the following raw materials in parts by mass: 10 to 20 parts of titanium aluminide powder, 2 to 8 parts of white mica powder, 5 to 15 parts of boron nitride powder, 65 to 75 parts of Al-based mixed powder and 0.1 to 5 parts of binder, the Al-based mixed powder is at least one of aluminum powder, aluminum oxide pellets and aluminum oxide ground powder. The plasma spraying technology of the multi-component sealing coating powder material is good in adaptability, the prepared coating is high in quality and stability, and the problems that due to the fact that traditional aluminum-based suspension coating is large in component fluctuation and insufficient in machining technology stability, the coating structure uniformity is poor, the coating bonding strength is low, and the abradability is poor are solved.

Description

Technical Field

[0001] The invention relates to the technical field of thermal spraying materials, and in particular to a multi-component sealing coating powder material and a preparation method thereof. Background Art

[0002] With the rapid development of the aviation industry, higher and higher requirements are being placed on the thrust, efficiency and fuel consumption of aircraft engines. As a key technology in aircraft engines, abradable sealing coatings can improve the overall air tightness of aircraft engines without damaging the blades, which is of great significance for improving the overall efficiency of aircraft engines, reducing fuel consumption and extending the life of components.

[0003] The components of abradable sealing coating materials are relatively complex, including metals, alloys, ceramics, inorganic non-metals, etc. The coating materials are in the form of powders, rods, wires, or solid-liquid mixed coatings. The spraying processes and equipment corresponding to different materials and forms are also different. Compared with conventional thermal spraying, the sealing coating prepared by coating and curing an inorganic suspension coating prepared with a binder and a metal-ceramic composite powder has been used in key components for many years due to its advantages such as no thermal impact on the substrate and low coating processing and maintenance costs. However, the inorganic suspension coating still has the following problems: 1. The binder and metal-ceramic composite powder contained in the suspension coating have complex components, the prepared suspension components are not consistent enough, the viscosity fluctuates greatly, and during spraying construction, the liquid volume consistency on the surface of the workpiece is poor in a single spraying, the spraying process is not stable enough, and the coating after spraying, sintering and curing will partially fall off during post-processing, requiring secondary repair treatment, affecting the quality of the abradable sealing coating and the processing progress; 2. The suspension coating is sprayed by a traditional manual spray gun, and discontinuous discharge problems often occur during the spraying process. The coating liquid is prone to local uneven adhesion on the surface of the part, resulting in fluctuations in the density of the cured coating and insufficient uniformity of the coating structure, which directly affects the coating hardness, bonding strength, abradability and other properties. Summary of the invention

[0004] In order to overcome the problems of large component fluctuations and unstable manual spraying process in existing aluminum-based inorganic suspension coatings, which result in poor coating tissue uniformity, low bonding strength and easy shedding, the present invention provides a multi-component sealing coating powder material and a preparation method thereof.

[0005] In order to achieve the above object, the present invention provides the following technical solutions: One of the technical solutions of the present invention is a multi-component sealing coating powder material, wherein the raw materials are 10 to 20 parts of titanium aluminide powder, 2 to 8 parts of muscovite powder, 5 to 15 parts of boron nitride powder, 65 to 75 parts of Al-based mixed powder and 0.1 to 5 parts of a binder in terms of weight; the Al-based mixed powder is at least one of aluminum powder, alumina pellets and alumina ground powder.

[0006] A second technical solution of the present invention is a method for preparing the above-mentioned multi-component sealing coating powder material, comprising the following steps: Titanium aluminide powder, muscovite powder, boron nitride powder and Al-based mixed powder are mixed and ball-milled to obtain a mixture; The mixed material and the binder are uniformly mixed and granulated, and then dried and sieved to obtain a multi-component sealing coating powder material.

[0007] A third technical solution of the present invention is an application of the above-mentioned multi-component sealing coating powder material in the preparation of sealing coating by plasma spraying.

[0008] The present invention discloses the following technical effects: The present invention adopts aluminum-based metals such as aluminum powder, aluminum oxide powder, and aluminum oxide balls, oxides (aluminum oxide) or intermetallic compounds (titanium aluminide powder) as skeleton components, and has high specific strength, specific elastic modulus, good oxidation resistance, creep resistance, excellent high-temperature strength, rigidity and low density, etc., which can improve the oxidation resistance and high-temperature strength of the coating and effectively reduce the density of the coating; hexagonal boron nitride is used as the abradable lubricating phase to increase the lubricity and abradability of the coating; muscovite has a hard texture and high mechanical strength, can withstand high temperature and rapid temperature changes, and has good physical and chemical properties such as acid and alkali resistance, which can increase the acid and alkali resistance and electrical insulation performance of the coating, improve the frost resistance, corrosion resistance, toughness and compactness of the coating, reduce the air permeability of the coating, and prevent spots and cracks. The multi-component aluminum-based sealing composite powder is produced by adopting composite processes such as "ball milling mixing, agglomeration stirring granulation". It has good adaptability to plasma spraying process and the prepared coating has high quality and stability. It solves the problems of traditional aluminum-based suspension coatings due to large component fluctuations and insufficient processing technology stability, resulting in poor coating uniformity, low coating hardness and bonding strength.

[0009] After the multi-component sealing coating powder material of the present invention is plasma sprayed, the obtained sealing coating has uniform structure, significantly improved bonding strength and abradability, an IDR value of 4.5-9.8%, a bonding strength of 9.6-12.3MPa, and a coating hardness of 57.8-62.2HR15Y.

[0010] The powder coating material prepared by the present invention has the advantages of good melting deposition effect, precise control of powder feeding rate, wide variety and strong applicability, convenient and fast transportation and storage, etc. The powder material spraying process has good adaptability and high coating quality and stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0012] Figure 1 This is a morphology photo of the multi-component sealing coating powder material prepared in Example 1; Figure 2 This is a microscopic morphology photograph of a sealing coating obtained by plasma spraying the multi-component sealing coating powder material prepared in Example 1; Figure 3 This is a photograph of the morphology of the sealing coating obtained by plasma spraying the multi-component sealing coating powder material prepared in Example 1 after grinding and scraping; Figure 4 The morphology photograph of the blade after grinding and scraping the sealing coating obtained by plasma spraying the multi-component sealing coating powder material prepared in Example 1; Figure 5 This is a microstructure morphology photograph of the sealing coating obtained by coating and curing the multi-component aluminum-based sealing coating material prepared in Comparative Example 1; Figure 6 This is a photograph of the morphology of the sealing coating obtained by coating and curing the multi-component aluminum-based sealing coating material prepared in Comparative Example 1 after grinding and scraping; Figure 7 This is a photo of the morphology of the blade after the sealing coating obtained by coating and curing the multi-component aluminum-based sealing coating material prepared in Comparative Example 1 was ground and scraped; Figure 8 This is a photograph of the morphology of the sealing coating obtained by plasma spraying the multi-component aluminum-based sealing coating material prepared in Comparative Example 3 after grinding and scraping; Fig. 9 This is a photograph of the morphology of the blade after grinding and scraping the sealing coating obtained by plasma spraying the multi-component aluminum-based sealing coating material prepared in Comparative Example 3. DETAILED DESCRIPTION

[0013] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0014] It should be understood that the terms described in the present invention are only for describing a particular embodiment and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0015] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0016] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to the skilled artisan. The present invention description and examples are exemplary only.

[0017] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0018] With the development of thermal spraying technology, sealing coating materials are mainly powders. Powder-shaped coating materials have the advantages of good melting deposition effect, precise control of powder feeding rate, strong applicability, convenient and fast transportation and storage, etc.; plasma spraying is currently a more advanced thermal spraying technology. Plasma spraying uses the principle of generating high-temperature arcs under the ionized state of gas to heat and accelerate the coating material. The center temperature of the plasma flame flow is as high as 30,000°C and the particle flight speed is as high as 400m / s. It can significantly improve the density and bonding strength of the coating tissue, and can generate enough energy to melt almost all powdered coating materials. It can spray various powder materials such as metal powder, ceramic powder, metal ceramic powder, composite powder, etc., and can prepare various functional coatings such as sealing coating, anti-ablation coating, thermal barrier coating and wear-resistant coating. At the same time, the equipment has a high degree of automation, can realize closed-loop control, stable process, and good consistency of coating quality. The plasma spraying process of powder materials has good adaptability, and the prepared coating has high quality and stability. In order to prepare high-quality coatings, the present invention provides a multi-component sealing coating powder material suitable for plasma spraying.

[0019] The first aspect of the present invention provides a multi-component sealing coating powder material, wherein the raw materials are 10 to 20 parts of titanium aluminide powder, 2 to 8 parts of muscovite powder, 5 to 15 parts of boron nitride powder, 65 to 75 parts of Al-based mixed powder and 0.1 to 5 parts of a binder in terms of mass percentage; the Al-based mixed powder is at least one of aluminum powder, alumina pellets and alumina ground powder.

[0020] In a preferred embodiment of the present invention, the raw materials are 10 to 15 parts of titanium aluminide powder, 3 to 6 parts of muscovite powder, 8 to 12 parts of boron nitride powder, 68 to 73 parts of Al-based mixed powder and 0.1 to 3 parts of binder, calculated by mass; the Al-based mixed powder is at least one of aluminum powder, alumina balls, and alumina powder.

[0021] In a preferred embodiment of the present invention, the raw materials are 12 to 15 parts of titanium aluminide powder, 4 to 6 parts of muscovite powder, 8 to 11 parts of boron nitride powder, 70 to 73 parts of Al-based mixed powder and 0.1 to 2 parts of binder, calculated by mass; the Al-based mixed powder is at least one of aluminum powder, alumina balls, and alumina powder.

[0022] In a preferred embodiment of the present invention, the mass ratio of aluminum powder, alumina balls and alumina powder in the Al-based mixed powder is 6.5-7:1.4-1.6:1 (further preferably, 6.5:1.5:1).

[0023] In the present invention, the composition of the multi-component sealing coating powder material is, by mass percentage, Ti 2-9%, boron nitride 5-15%, SiO2 1-4%, binder 0.1-5.0%, and the balance is Al and other inevitable impurities. In the present invention, the Ti element in the multi-component sealing coating powder material is provided by titanium aluminide powder, SiO2 is provided by muscovite powder, and the Al-based mixed powder provides the remaining required aluminum element. The impurities in the multi-component sealing coating powder material are brought in by the inevitable impurities in the raw materials, for example: in addition to SiO2, muscovite powder also contains potassium oxide, magnesium oxide, etc.

[0024] In a preferred embodiment of the present invention, the binder is prepared by dissolving CrO3 in an aluminum dihydrogen phosphate solution; the mass concentration of the aluminum dihydrogen phosphate solution is 50% to 80%; and the concentration of CrO3 in the binder is 65 to 75 g / L.

[0025] In a preferred embodiment of the present invention, the particle size of the titanium aluminide powder is 10 to 180 μm; the particle size of the muscovite powder is 10 to 180 μm; the boron nitride powder is hexagonal boron nitride powder; the particle size of the hexagonal boron nitride powder is 5 to 20 μm; the particle size of the aluminum powder is 10 to 180 μm; the particle size of the alumina powder is 35 to 75 μm; and the particle size of the alumina balls is 10 to 180 μm.

[0026] The second aspect of the present invention provides a method for preparing the above-mentioned multi-component sealing coating powder material, comprising the following steps: Titanium aluminide powder, muscovite powder, boron nitride powder and Al-based mixed powder are mixed and ball-milled to obtain a mixture; The mixed material and the binder are uniformly mixed and granulated, and then dried and sieved to obtain a multi-component sealing coating powder material.

[0027] In a preferred embodiment of the present invention, the ball milling time is 10 h to 14 h, and the rotation speed is 40 rpm to 60 rpm. After ball milling, the obtained mixture is collected using a 30-mesh sieve.

[0028] In a preferred embodiment of the present invention, the drying temperature is 110-130° C. and the drying time is 4 h-6 h.

[0029] In a preferred embodiment of the present invention, the granulation is specifically as follows: adding the mixture into a granulator, then adding a binder, performing agglomeration and stirring granulation, the stirring speed is 40rpm~80rpm, the stirring time is 1~3h, and a granular multi-component sealing coating powder material is obtained.

[0030] In a preferred embodiment of the present invention, the sieving is performed using 60 mesh and 325 mesh sieves respectively. After sieving, a multi-component sealing coating powder material with a particle size of 45-300 μm is obtained.

[0031] A third aspect of the present invention provides an application of the above-mentioned multi-component sealing coating powder material in preparing a sealing coating by plasma spraying.

[0032] The technical solutions described in the present invention, unless otherwise specified, are all conventional solutions in the art, and the reagents or raw materials used, unless otherwise specified, are purchased from commercial channels or have been disclosed.

[0033] In order to better understand the present invention, the content of the present invention is further explained below in conjunction with the embodiments, but the content of the present invention is not limited to the following embodiments.

[0034] In the embodiment, the particle sizes of the materials are: the particle size of titanium aluminide powder is 10 to 180 μm; the particle size of muscovite powder is 10 to 180 μm; the boron nitride powder is hexagonal boron nitride powder; the particle size of hexagonal boron nitride powder is 5 to 20 μm; the particle size of aluminum powder is 10 to 180 μm; the particle size of alumina powder is 35 to 75 μm; and the particle size of alumina balls is 10 to 180 μm.

[0035] Example 1

[0036] A multi-component sealing coating powder material, the preparation steps are as follows: Step 1: Place 2.64 kg aluminum powder, 0.38 kg aluminum oxide powder, 0.60 kg aluminum oxide balls, 0.75 kg titanium aluminide powder, 0.29 kg muscovite powder and 0.53 kg hexagonal boron nitride powder into a ball mill.

[0037] Step 2: Add 3 kg of zirconium oxide grinding balls into the ball mill barrel, the ball mill speed is 50 rpm, and the ball milling time is 12 hours.

[0038] Step 3: Use a 30-mesh sieve that complies with GB T 5330-2003 standard to sieve the powder obtained in step 2 and collect the mixed material.

[0039] Step 4: Measure 1200 ml of aluminum dihydrogen phosphate solution with a mass concentration of 70%, add 84 g of CrO3 powder, and stir evenly to completely dissolve it to obtain an aluminum chromium phosphate binder.

[0040] Step 5: Add the mixture obtained in step 3 into a granulator, and then add the binder obtained in step 4, start stirring, the stirring speed is 70 rpm, and the stirring time is 2.5 hours, until the powder is granular.

[0041] Step 6: After stirring stops, the granular material obtained in step 5 is placed in an oven for drying at a temperature of 120°C for 4 hours.

[0042] Step 7: Use a 160-mesh sieve and a 325-mesh sieve that conform to the GB T 5330-2003 standard to sieve the granular material obtained in step 6, and the powder obtained with a mesh size below 60 and a mesh size above 325 is the multi-component sealing coating powder material. The morphology photo of the multi-component sealing coating powder material is shown in FIG. Figure 1 shown.

[0043] The multi-component sealing coating powder material prepared in this embodiment is plasma sprayed, and the parameters of plasma spraying are: main gas flow rate 25-45NLPM, auxiliary gas flow rate 5-10NLPM, carrier gas flow rate 3-6NLPM, current 500-600A, spraying power 30-40kW, powder feeding rate 20-50g / min, spraying distance 80-120mm, and gun travel rate 3-8mm / s. During the plasma spraying process, the powder feeding is smooth and uninterrupted, and the prepared sealing coating has uniform structure, and the bonding strength and abradability are significantly improved. Figure 2 This is a photo of the microstructure of the coating after plasma spraying. Under the conditions of high temperature and high speed grinding and scraping with titanium alloy blades at 300℃, 300m / s, and 50μm / s, the coating wear marks are smooth and flat ( Figure 3 )、No wear on the blade tip( Figure 4 ), the abradability is significantly improved, and the IDR value is 6.3%. The bonding strength of the plasma sprayed coating is 10.9MPa; the coating hardness is 59.8 HR15Y.

[0044] Comparative Example 1 A multi-component aluminum-based sealing coating material, the preparation steps are as follows: Step 1: Same as step 1 in Example 1.

[0045] Step 2: Same as step 2 in Example 1.

[0046] Step 3: Same as step 3 in Example 1.

[0047] Step 4: Measure 3800 ml of aluminum dihydrogen phosphate solution with a mass concentration of 30%, add 84 g of CrO3 powder, and stir evenly to make it completely dissolved to obtain a suspension coating (i.e., a multi-component aluminum-based sealing coating material).

[0048] The suspension coating of this comparative example was used to prepare a sealing coating by coating and curing, and the coating structure was uneven ( Figure 5 ), under the conditions of high temperature and high speed grinding and scraping with titanium alloy blades at 300℃, 300m / s, and 50μm / s, the coating was hardly scraped ( Figure 6 )、The blades are severely worn and deformed ( Figure 7 ), IDR value is 76%, and abradability is poor. The coating prepared by the suspension coating has a bonding strength of 4.5MPa and a hardness of 52.2HR15Y.

[0049] Comparative Example 2 A multi-component aluminum-based sealing coating material, the preparation steps are as follows: Step 1: Same as step 1 in Example 1.

[0050] Step 2: Same as step 2 in Example 1.

[0051] Step 3: Same as step 3 in Example 1.

[0052] Step 4: Measure 1000 ml of aluminum dihydrogen phosphate solution with a mass concentration of 70%, add 170 g of CrO3 powder, and stir evenly to completely dissolve it to obtain an aluminum chromium phosphate binder.

[0053] Step 5: Same as step 5 of Example 1.

[0054] Step 6: Same as step 6 in Example 1.

[0055] Step 7: Same as step 7 in Example 1.

[0056] Compared with Example 1, the amount of binder added in this comparative example is too much, resulting in uneven particles of the prepared multi-component sealing coating powder material, coarse particle size, and poor adaptability to plasma spraying.

[0057] Comparative Example 3 The only difference from Example 1 is that 2.64 kg of aluminum powder is replaced by 3.2 kg of aluminum powder, and the other steps and parameters are the same as those in Example 1.

[0058] The multi-component sealing coating powder material of this comparative example was plasma sprayed, and the plasma spraying parameters were the same as those of Example 1. The hardness of the obtained coating was 39.5 HR15Y, and the bonding strength was 5.7 MPa. Under the conditions of high temperature and high speed grinding and scraping with titanium alloy blades at 300°C, 300m / s, and 50μm / s, the coating surface had grooves ( Figure 8 ), there are obvious sticking marks on the leaf tips ( Fig. 9 ), the IDR value is -15.5%, and the abradability is poor. That is, compared with Example 1, the amount of aluminum added is too much, resulting in reduced coating hardness and bonding strength, and reduced abradability (negative IDR value, blade tip adhesion).

[0059] Comparative Example 4 The only difference from Example 1 is that 0.29 kg of muscovite powder is replaced by 0.52 kg of muscovite powder, and the other steps and parameters are the same as those in Example 1.

[0060] The multi-component sealing coating powder material of this comparative example was plasma sprayed, and the plasma spraying parameters were the same as those of Example 1. The hardness of the obtained coating was 76.4 HR15Y; under the conditions of high temperature and high speed grinding and scraping with titanium alloy blades at 300°C, 300m / s, and 50μm / s, the coating surface had grooves, the blade tip was severely worn, the IDR value was 18.9%, and the abradability was poor. That is, compared with Example 1, the amount of muscovite added was too much, resulting in an increase in the hardness of the coating and a decrease in the abradability (the IDR value increased, and the blade wear increased).

[0061] Comparative Example 5 The only difference from Example 1 is that the addition of hexagonal boron nitride is omitted, and the other steps and parameters are the same as those in Example 1.

[0062] The multi-component sealing coating powder material of this comparative example was plasma sprayed, and the plasma spraying parameters were the same as those of Example 1. The hardness of the obtained coating was 61.3 HR15Y; under the conditions of high temperature and high speed grinding and scraping with titanium alloy blades at 300°C, 300m / s, and 50μm / s, the coating surface had grooves, and the blade tip adhesion was more obvious. The IDR value was -23.6%, and the abradability was poor. That is, compared with Example 1, without adding hexagonal boron nitride powder to the raw materials, the coating hardness was slightly increased, the abradability was reduced, and the blade tip adhesion was more obvious.

[0063] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A multi-component sealing coating powder material, characterized in that: The raw materials are 10-20 parts of titanium aluminide powder, 2-8 parts of muscovite powder, 5-15 parts of boron nitride powder, 65-75 parts of Al-based mixed powder and 0.1-5 parts of binder in terms of mass; the Al-based mixed powder is at least one of aluminum powder, alumina balls and alumina powder.

2. The multi-component sealing coating powder material according to claim 1, characterized in that: The mass ratio of aluminum powder, alumina balls and alumina powder in the Al-based mixed powder is 6.5-7:1.4-1.6:

1.

3. The multi-component sealing coating powder material according to claim 1, characterized in that: The binder is prepared by dissolving CrO3 in a dihydrogen aluminum phosphate solution; the mass concentration of the dihydrogen aluminum phosphate solution is 50% to 80%; and the concentration of CrO3 in the binder is 65 to 75 g / L.

4. The multi-component sealing coating powder material according to claim 1, characterized in that: The particle size of the titanium aluminide powder is 10 to 180 μm; the particle size of the muscovite powder is 10 to 180 μm; the boron nitride powder is hexagonal boron nitride powder; the particle size of the hexagonal boron nitride powder is 5 to 20 μm; the particle size of the aluminum powder is 10 to 180 μm; the particle size of the alumina powder is 35 to 75 μm; and the particle size of the alumina balls is 10 to 180 μm.

5. A method for preparing the multi-component sealing coating powder material according to any one of claims 1 to 4, characterized in that: The following steps are involved: Titanium aluminide powder, muscovite powder, boron nitride powder and Al-based mixed powder are mixed and ball-milled to obtain a mixture; The mixed material and the binder are uniformly mixed and granulated, and then dried and sieved to obtain a multi-component sealing coating powder material.

6. The method for preparing a multi-component sealing coating powder material according to claim 5, characterized in that: The ball milling time is 10h~14h, and the rotation speed is 40rpm~60rpm.

7. The method for preparing a multi-component sealing coating powder material according to claim 5, characterized in that: The drying temperature is 110-130° C. and the drying time is 4-6 hours.

8. The method for preparing a multi-component sealing coating powder material according to claim 5, characterized in that: The sieving is performed using 60-mesh and 325-mesh sieves respectively.

9. Use of the multi-component sealing coating powder material according to any one of claims 1 to 4 in preparing sealing coating by plasma spraying.

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