Preparation method of hypersonic-velocity-resistant niobium-tungsten alloy coating

Abstract

The invention relates to the technical field of high-temperature coatings, and discloses a preparation method of a hypersonic-speed-resistant niobium-tungsten alloy coating, which comprises the following steps: S1, putting niobium-tungsten alloy into ultrasonic cleaning equipment, and cleaning for 10-30 minutes; an oxide layer and oil stains on the surface of the niobium-tungsten alloy are removed through cleaning, so that the natural color of the metal is exposed; after cleaning is completed, mechanical property index testing needs to be carried out on the niobium-tungsten alloy, and therefore it is ensured that whether the niobium-tungsten alloy material meets the use requirement or not. According to the preparation method of the hypersonic-speed-resistant niobium-tungsten alloy coating, the coating obtained through the steps has good oxidation resistance and high-temperature resistance, so that the phenomenon that niobium-tungsten alloy is damaged due to friction between the niobium-tungsten alloy and the atmosphere at the hypersonic speed in the using process is avoided, and the durability and firmness of the material are improved; and meanwhile, the production steps of the process are simple and convenient, so that the production efficiency of the niobium-tungsten alloy is improved.

Description

Technical Field

[0001] The invention relates to the technical field of high-temperature coatings, and in particular to a method for preparing a hypersonic resistant niobium-tungsten alloy coating. Background Art

[0002] At present, my country is expanding the space launch vehicle industry to support satellite launch services and manned space and lunar exploration programs. While expanding the space launch vehicle industry, rocket engines are also constantly upgrading. With the upgrading of rocket engines, new high-temperature and high-specific-strength niobium tungsten alloy (Nb521) materials are increasingly used in high-temperature engine components. Most of the niobium tungsten alloy (Nb521) used in these high-temperature components is a material with a high-temperature oxidation-resistant and corrosion-resistant coating on the surface.

[0003] However, most of the existing coatings have loose coating structures and large gaps between coating powders. In a high-temperature atmospheric environment, due to oxygen erosion, the coating first starts to be destroyed from the powder gaps and then spreads. This localized destruction causes the entire part to be scrapped prematurely, greatly shortening the overall life of the part and the coating. In addition, the bonding strength between the niobium tungsten alloy (Nb521) high-temperature anti-oxidation coating and the substrate is not strong, and the coating is brittle. If the coating is bent more than 45°, it will break brittlely, and the coating in the bending area will fall off, resulting in the coating being unusable on high-temperature workpieces that need to be bent during installation or work. Summary of the invention

[0004] 1. Technical issues to be solved

[0005] In view of the shortcomings of the prior art, the present invention provides a method for preparing a hypersonic resistant niobium tungsten alloy coating, which solves the problem that most of the existing coatings have loose coating structures and large gaps between coating powders. In a high-temperature atmospheric environment, due to oxygen erosion, the coating first starts to be destroyed from the powder gaps and then spreads. This localized destruction causes the entire part to be scrapped prematurely, greatly shortening the overall life of the part and the coating.

[0006] (II) Technical solution

[0007] To achieve the above object, the present invention provides the following technical solution: a method for preparing a hypersonic resistant niobium tungsten alloy coating, comprising the following steps;

[0008] S1. Place the niobium tungsten alloy in an ultrasonic cleaning device for cleaning for 10-30 minutes;

[0009] Remove the oxide layer and oil stains on the surface of niobium tungsten alloy by cleaning, thus revealing the original color of the metal;

[0010] Among them, after cleaning, the niobium tungsten alloy needs to be tested for mechanical properties to ensure whether the niobium tungsten alloy material meets the use requirements;

[0011] S2. Grind molybdenum, boron carbide, silicon and boron into powder with a particle size of 20-40 microns using a ball mill, add graphite powder and mix evenly, and add corresponding organic solvent;

[0012] The ratio of molybdenum, silicon, boron, graphite powder and boron carbide is 1:2:2:1:2;

[0013] S3, placing the niobium tungsten alloy after cleaning in S1 on a fixed rack, and at this time, placing the powder obtained in S2 into a powder feeder, and adjusting the working air pressure at the inlet of the spray gun nozzle to 2-4Mpa and the temperature to 400-500°C;

[0014] The spraying speed is 15 grams per minute. During the working process, the temperature is gradually increased to 500-600℃ and the air pressure is adjusted to 4Mpa.

[0015] S4. After step S3 is completed, the niobium tungsten alloy is placed in a high-temperature atmosphere furnace, and is subjected to a heat preservation treatment at 1400°C for 1 hour at a heating rate of 10°C / min under an argon protective atmosphere. After the alloy is naturally cooled to room temperature, it is taken out to form a protective coating on its surface.

[0016] Preferably, the vacuum degree of the high temperature atmosphere furnace in S4 is not less than 2x10-2Pa.

[0017] Preferably, the cleaning method in S1 is pickling, which can remove impurities such as oil stains and oxides on the surface of the niobium tungsten alloy. The solution used for pickling is acid solution, which includes nitric acid and sulfuric acid, and the mass ratio of nitric acid to sulfuric acid is 4:2; the pickling time is controlled at 20 minutes, and then ultrasonic cleaning is carried out with deionized water, and then drying is carried out.

[0018] Preferably, after the grinding in S2 is completed, the material needs to be screened, so unqualified materials are removed and the unqualified materials are ground again.

[0019] Preferably, the working gas in S3 is nitrogen.

[0020] Preferably, the fixing frame in S3 is a common fixing device, and it needs to be protected during the process of fixing the niobium tungsten alloy to avoid surface wear.

[0021] (III) Beneficial effects

[0022] Compared with the prior art, the present invention provides a method for preparing a hypersonic resistant niobium tungsten alloy coating, which has the following beneficial effects:

[0023] 1. The preparation method of the anti-hypersonic niobium tungsten alloy coating. The coating obtained through the above steps has good oxidation resistance and high temperature resistance, so that the niobium tungsten alloy will not be damaged due to hypersonic friction with the atmosphere during use, thereby improving the durability and firmness of the material. At the same time, the process production steps are simple and convenient, thereby improving the production efficiency of the niobium tungsten alloy.

[0024] 2. The method for preparing the anti-hypersonic niobium tungsten alloy coating is to carve indentations on the surface of the niobium tungsten alloy so that when the niobium tungsten alloy contacts the coating, the two can adhere more firmly and are less likely to delaminate, thereby ensuring the use effect of the coating. DETAILED DESCRIPTION

[0025] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0026] Embodiment 1:

[0027] A method for preparing a hypersonic resistant niobium tungsten alloy coating, comprising the following steps:

[0028] S1. Place the niobium tungsten alloy in an ultrasonic cleaning device for cleaning for 10-30 minutes;

[0029] The cleaning method is pickling, which can remove impurities such as oil stains and oxides on the surface of niobium tungsten alloy. The solution used for pickling is acid solution, which includes nitric acid and sulfuric acid. The mass ratio of nitric acid to sulfuric acid is 4:2. The pickling time is controlled at 20 minutes, and then ultrasonic cleaning is performed with deionized water, and then drying is performed.

[0030] S2. Grind molybdenum, boron carbide, silicon and boron into powder with a particle size of 20-40 microns using a ball mill, and add graphite powder to mix evenly;

[0031] The ratio of molybdenum, silicon, boron, graphite powder and boron carbide is 1:2:2:1:2;

[0032] Among them, after grinding, the materials need to be screened, so unqualified materials are removed and the unqualified materials are ground again;

[0033] S3, placing the niobium tungsten alloy after cleaning in S1 on a fixed rack, and at this time, placing the powder obtained in S2 into a powder feeder, and adjusting the working air pressure at the inlet of the spray gun nozzle to 2-4Mpa and the temperature to 400-500°C;

[0034] The spraying speed is 15 grams per minute. During the working process, the temperature is gradually increased to 500-600℃ and the air pressure is adjusted to 4Mpa.

[0035] Use nitrogen as working gas;

[0036] Among them, the fixing frame is a common fixing device, and it needs to be protected during the fixing process of niobium tungsten alloy to avoid surface wear;

[0037] S4, after the step S3 is completed, the niobium tungsten alloy is placed in a high temperature atmosphere furnace, and in an argon protective atmosphere, the niobium tungsten alloy is subjected to a heat preservation treatment at 1400°C for 1 hour at a heating rate of 10°C / min, and then taken out after naturally cooling to room temperature, so that a protective coating is formed on the surface thereof;

[0038] Among them, the vacuum degree of the high temperature atmosphere furnace is not less than 2x10-2Pa.

[0039] The coating obtained through the above steps has good antioxidant ability and high temperature resistance, so the niobium tungsten alloy will not be damaged due to hypersonic friction with the atmosphere during use, thereby improving the durability and firmness of the material. At the same time, the process production steps are simple and convenient, thereby improving the production efficiency of the niobium tungsten alloy.

[0040] Embodiment 2:

[0041] A method for preparing a hypersonic resistant niobium tungsten alloy coating, comprising the following steps:

[0042] S1. Place the niobium tungsten alloy in an ultrasonic cleaning device for cleaning for 10-30 minutes;

[0043] The cleaning method is pickling, which can remove impurities such as oil stains and oxides on the surface of niobium tungsten alloy. The solution used for pickling is acid solution, which includes nitric acid and sulfuric acid. The mass ratio of nitric acid to sulfuric acid is 4:2. The pickling time is controlled at 20 minutes, and then ultrasonic cleaning is performed with deionized water, and then drying is performed.

[0044] S2. Grind molybdenum, silicon and boron into powder with a particle size of 20-40 microns using a ball mill, and add graphite powder to mix evenly;

[0045] The ratio of molybdenum, silicon and boron is 1:2:2;

[0046] Among them, after grinding, the materials need to be screened, so unqualified materials are removed and the unqualified materials are ground again;

[0047] S3, placing the niobium tungsten alloy cleaned in S1 on a fixed rack, and then placing the powder obtained in S3 into a powder feeder, and adjusting the working air pressure at the inlet of the spray gun nozzle to 2-4Mpa and the temperature to 480°C;

[0048] The spraying speed is 15g / min. During the working process, the temperature is gradually raised to 560℃ and the air pressure is adjusted to 4Mpa.

[0049] Use nitrogen as working gas;

[0050] Among them, the fixing frame is a common fixing device, and it needs to be protected during the fixing process of niobium tungsten alloy to avoid surface wear;

[0051] S4, after the step S3 is completed, the niobium tungsten alloy is placed in a high-temperature atmosphere furnace, and in an argon protective atmosphere, the niobium tungsten alloy is subjected to a heat preservation treatment at 800°C for 1 hour at a heating rate of 10°C / min, and then taken out after naturally cooling to room temperature, so that a protective coating is formed on the surface thereof;

[0052] Among them, the vacuum degree of the high temperature atmosphere furnace is not less than 2x10-2Pa;

[0053] The coating obtained through the above steps has good antioxidant ability and high temperature resistance, so the niobium tungsten alloy will not be damaged due to hypersonic friction with the atmosphere during use, thereby improving the durability and firmness of the material. At the same time, the process production steps are simple and convenient, thereby improving the production efficiency of the niobium tungsten alloy.

[0054] Embodiment three:

[0055] A method for preparing a hypersonic resistant niobium tungsten alloy coating, comprising the following steps:

[0056] S1. Place the niobium tungsten alloy in an ultrasonic cleaning device for cleaning for 10-30 minutes;

[0057] The cleaning method is pickling, which can remove impurities such as oil stains and oxides on the surface of niobium tungsten alloy. The solution used for pickling is acid solution, which includes nitric acid and sulfuric acid. The mass ratio of nitric acid to sulfuric acid is 4:2. The pickling time is controlled at 20 minutes, and then ultrasonic cleaning is performed with deionized water, and then drying is performed.

[0058] S2. Grind molybdenum, silicon and boron into powder with a particle size of 20-40 microns using a ball mill, and add graphite powder to mix evenly;

[0059] The ratio of molybdenum, silicon and graphite powder is 1:2:1;

[0060] Among them, after grinding, the materials need to be screened, so unqualified materials are removed and the unqualified materials are ground again;

[0061] S3, placing the niobium tungsten alloy cleaned in S1 on a fixed rack, and then placing the powder obtained in S3 into a powder feeder, and adjusting the working pressure at the inlet of the spray gun nozzle to 2-4Mpa and the temperature to 430°C;

[0062] The spraying speed is 15g / min. During the working process, the temperature is gradually raised to 540℃ and the air pressure is adjusted to 4Mpa.

[0063] Use nitrogen as working gas;

[0064] Among them, the fixing frame is a common fixing device, and it needs to be protected during the fixing process of niobium tungsten alloy to avoid surface wear;

[0065] S4, after the step S3 is completed, the niobium tungsten alloy is placed in a high temperature atmosphere furnace, and in an argon protective atmosphere, the niobium tungsten alloy is subjected to a heat preservation treatment at 1400°C for 1 hour at a heating rate of 10°C / min, and then taken out after naturally cooling to room temperature, so that a protective coating is formed on the surface thereof;

[0066] The coating obtained through the above steps has good antioxidant ability and high temperature resistance, so the niobium tungsten alloy will not be damaged due to hypersonic friction with the atmosphere during use, thereby improving the durability and firmness of the material. At the same time, the process production steps are simple and convenient, thereby improving the production efficiency of the niobium tungsten alloy.

[0067] Embodiment 4:

[0068] A method for preparing a hypersonic resistant niobium tungsten alloy coating, comprising the following steps:

[0069] S1. Place the niobium tungsten alloy in an ultrasonic cleaning device for cleaning for 10-30 minutes;

[0070] The cleaning method is pickling, which can remove impurities such as oil stains and oxides on the surface of niobium tungsten alloy. The solution used for pickling is acid solution, which includes nitric acid and sulfuric acid. The mass ratio of nitric acid to sulfuric acid is 4:2. The pickling time is controlled at 20 minutes, and then ultrasonic cleaning is performed with deionized water, and then drying is performed.

[0071] S2. Grind molybdenum, silicon and boron into powder with a particle size of 20-40 microns using a ball mill, and add graphite powder to mix evenly;

[0072] The ratio of silicon, boron and graphite powder is 2:2:1;

[0073] Among them, after grinding, the materials need to be screened, so unqualified materials are removed and the unqualified materials are ground again;

[0074] S3, placing the niobium tungsten alloy cleaned in S1 on a fixed rack, and then placing the powder obtained in S3 into a powder feeder, and adjusting the working air pressure at the inlet of the spray gun nozzle to 2-4Mpa and the temperature to 450°C;

[0075] The spraying speed is 15g / min. During the working process, the temperature is gradually raised to 550℃ and the air pressure is adjusted to 4Mpa.

[0076] Use nitrogen as working gas;

[0077] Among them, the fixing frame is a common fixing device, and it needs to be protected during the fixing process of niobium tungsten alloy to avoid surface wear;

[0078] S4, after the step S3 is completed, the niobium tungsten alloy is placed in a high-temperature atmosphere furnace, and in an argon protective atmosphere, the niobium tungsten alloy is subjected to a heat preservation treatment at 800°C for 1 hour at a heating rate of 10°C / min, and then taken out after naturally cooling to room temperature, so that a protective coating is formed on the surface thereof;

[0079] The coating obtained through the above steps has good antioxidant ability and high temperature resistance, so the niobium tungsten alloy will not be damaged due to hypersonic friction with the atmosphere during use, thereby improving the durability and firmness of the material. At the same time, the process production steps are simple and convenient, thereby improving the production efficiency of the niobium tungsten alloy.

[0080] Embodiment five:

[0081] S1. Place the niobium tungsten alloy in an ultrasonic cleaning device for cleaning for 10-30 minutes;

[0082] The cleaning method is pickling, which can remove impurities such as oil stains and oxides on the surface of niobium tungsten alloy. The solution used for pickling is acid solution, which includes nitric acid and sulfuric acid. The mass ratio of nitric acid to sulfuric acid is 4:2. The pickling time is controlled at 20 minutes, and then ultrasonic cleaning is performed with deionized water, and then drying is performed.

[0083] S2. Grind molybdenum, silicon and boron into powder with a particle size of 20-40 microns using a ball mill, and add graphite powder to mix evenly;

[0084] The ratio of molybdenum, boron and graphite powder is 1:2:2;

[0085] Among them, after grinding, the materials need to be screened, so unqualified materials are removed and the unqualified materials are ground again;

[0086] S3, placing the niobium tungsten alloy after cleaning in S1 on a fixed rack, and then placing the powder obtained in S3 into a powder feeder, and adjusting the working air pressure at the inlet of the spray gun nozzle to 2-4Mpa and the temperature to 500°C;

[0087] The spraying speed is 15 grams per minute. During the working process, the temperature is gradually raised to 600°C and the gas pressure is adjusted to 4Mpa.

[0088] Use nitrogen as working gas;

[0089] Among them, the fixing frame is a common fixing device, and it needs to be protected during the fixing process of niobium tungsten alloy to avoid surface wear;

[0090] S4, after the step S3 is completed, the niobium tungsten alloy is placed in a high temperature atmosphere furnace, and in an argon protective atmosphere, the niobium tungsten alloy is subjected to a heat preservation treatment at 1400°C for 1 hour at a heating rate of 10°C / min, and then taken out after naturally cooling to room temperature, so that a protective coating is formed on the surface thereof;

[0091] The coating obtained through the above steps has good antioxidant ability and high temperature resistance, so the niobium tungsten alloy will not be damaged due to hypersonic friction with the atmosphere during use, thereby improving the durability and firmness of the material. At the same time, the process production steps are simple and convenient, thereby improving the production efficiency of the niobium tungsten alloy.

[0092] After the production of the present invention is completed, the test is carried out according to the national designated standards, and the following results are obtained through the test. The anti-supersonic test performance of the coating of the present invention is as follows:

[0093]

[0094] In the actual test process of the present invention, the coating has good antioxidant ability and high temperature resistance, so that the niobium tungsten alloy will not be damaged due to hypersonic friction with the atmosphere during use, thereby improving the durability and firmness of the material. At the same time, the process production steps are simple and convenient, thereby improving the production efficiency of the niobium tungsten alloy.

[0095] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a hypersonic resistant niobium tungsten alloy coating, comprising the following steps; S1. Place the niobium tungsten alloy in an ultrasonic cleaning device for cleaning for 10-30 minutes; Remove the oxide layer and oil stains on the surface of niobium tungsten alloy by cleaning, thus revealing the original color of the metal; in, After cleaning, the niobium tungsten alloy needs to be tested for mechanical properties to ensure that the niobium tungsten alloy material meets the use requirements; S2. Grind molybdenum, boron carbide, silicon and boron into powder with a particle size of 20-40 microns using a ball mill, add graphite powder and mix evenly, and add corresponding organic solvent; The ratio of molybdenum, silicon, boron, graphite powder and boron carbide is 1:2:2:1:2; S3, placing the niobium tungsten alloy after cleaning in S1 on a fixed rack, and at this time, placing the powder obtained in S2 into a powder feeder, and adjusting the working air pressure at the inlet of the spray gun nozzle to 2-4Mpa and the temperature to 400-500°C; The spraying speed is 15 grams per minute. During the working process, the temperature is gradually increased to 500-600℃ and the air pressure is adjusted to 4Mpa. S4. After step S3 is completed, the niobium tungsten alloy is placed in a high-temperature atmosphere furnace, and is subjected to a heat preservation treatment at 1400°C for 1 hour at a heating rate of 10°C / min under an argon protective atmosphere. After the alloy is naturally cooled to room temperature, it is taken out to form a protective coating on its surface.

2. The method for preparing a hypersonic resistant niobium tungsten alloy coating according to claim 1, characterized in that: The vacuum degree of the high temperature atmosphere furnace described in S4 is not less than 2x10-2Pa.

3. The method for preparing a hypersonic resistant niobium tungsten alloy coating according to claim 1, characterized in that: The cleaning method described in S1 is pickling, which can remove impurities such as oil stains and oxides on the surface of the niobium tungsten alloy. The solution used for pickling is acid solution, which includes nitric acid and sulfuric acid. The mass ratio of nitric acid to sulfuric acid is 4:2; the pickling time is controlled at 20 minutes, and then ultrasonic cleaning is performed with deionized water, and then drying is performed.

4. The method for preparing a hypersonic resistant niobium tungsten alloy coating according to claim 1, characterized in that: After the grinding described in S2 is completed, the materials need to be screened, so unqualified materials are removed and the unqualified materials are ground again.

5. The method for preparing a hypersonic resistant niobium tungsten alloy coating according to claim 1, characterized in that: The working gas in S3 is nitrogen.

6. The method for preparing a hypersonic resistant niobium tungsten alloy coating according to claim 1, characterized in that: The fixing frame described in S3 is a common fixing device, and it needs to be protected during the fixing process of the niobium tungsten alloy to avoid surface wear.

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