Stealth target material for aviation part coating and preparation method of stealth target material

Abstract

The invention provides a stealth target material for an aviation part coating and a preparation method of the stealth target material, and belongs to the technical field of thin film material infrared stealth, and the preparation method comprises the following steps: mixing metal silicon powder, silicon carbide powder, boron nitride powder and carbon powder in vacuum to obtain a mixture, filling the mixture into a mold, vacuumizing and then carrying out cold isostatic pressing to obtain a rough blank, and carrying out hot pressing on the rough blank to obtain the stealth target material. Secondary pressing is conducted, and an alloy target material green body is obtained; carrying out vacuum hot pressed sintering and demolding to obtain an alloy target material crude product; and then annealing is conducted, plasma spraying is conducted on the surface of the annealed alloy target material crude product, and the invisible target material for the aviation part coating is obtained. According to the preparation method, mixed materials are synthesized and manufactured in the vacuum environment, the influence of dust on the environment and workers is reduced, the product performance and the production effect are greatly improved, the production cost of a plane target and a rotating target is greatly reduced, and the prepared target has the excellent performance of being uniform in structure, small in grain size, high in heat shock resistance and the like; the method is especially suitable for production of large-area stealth film layers.

Description

Technical Field

[0001] The invention belongs to the technical field of infrared stealth of thin film materials, and in particular relates to a stealth target material for aviation component coating and a preparation method thereof. Background Art

[0002] Among the preparation methods of magnetron sputtering stealth film layers, the most widely studied and applied one is magnetron sputtering technology. Therefore, it has the advantages of high deposition rate, low substrate deposition temperature, good film adhesion, easy control, low cost, and can achieve large-area film formation. It has become the most industrially produced, most studied, most mature, and most widely used film-forming technology, and is also the most commonly used method for the preparation of stealth films. The alloy rotating target material mixed with metal silicon powder, silicon carbide powder, boron nitride powder and carbon powder has become an important material for the preparation of stealth films. The core technical difficulty of the alloy target material mixed with silicon powder, silicon carbide powder, boron nitride powder and carbon powder lies in controlling the cracking and low density problems during the molding process, as well as the uniformity control of the shrinkage of the stealth target material during the sintering process. The most difficult links in the quality of the existing melting and casting technology are mainly two: on the one hand, the quantitative control of gas, trace impurities and inclusions in the melt in a complex atmospheric environment; on the other hand, the control of looseness, cracks, segregation and uneven organization in large-scale ingots. Sometimes even problems such as surface pores, inclusions and chemical waste can get out of control. These casting quality problems are closely related to the properties of the metal and the casting process conditions. Summary of the invention

[0003] The present application provides a stealth target material for aviation component coating and a preparation method thereof, aiming to solve the problem that impurities and gases cannot be quantitatively controlled in melting and casting technology to a certain extent.

[0004] In a first aspect, the present application provides a method for preparing a stealth target material for aviation component coating, comprising the following steps: S1, mixing metallic silicon powder, silicon carbide powder, boron nitride powder and carbon powder in a vacuum rolling mixer to obtain a mixture; S2, filling the mixture into a mold, evacuating the mold and cold isostatically pressing the mold to obtain a rough billet, and performing secondary pressing on the rough billet to obtain a green billet of an alloy target; S3, performing vacuum hot pressing sintering on the alloy target green body, and demolding to obtain a crude alloy target; S4, machining the crude alloy target material for annealing, ball-milling the mixture described in S1 and then plasma spraying the mixture onto the surface of the annealed crude alloy target material to obtain a stealth target material for aviation component coating.

[0005] In a second aspect, the present application provides a stealth target material for aviation part coating obtained by the preparation method described in the first aspect.

[0006] Compared with the prior art, the beneficial effects of this application are: 1. Mixing and synthesizing in a vacuum environment reduces the impact of dust on the environment and workers, greatly improving product performance and production results. It not only greatly reduces the production cost of planar targets and rotating targets, but also the prepared targets have excellent properties such as uniform structure, fine grains, and high heat shock resistance, which is especially suitable for the production of large-area stealth thin film layers.

[0007] 2. The plane target and rotating target prepared by the present invention have high density, good conductivity and reflectivity. During the sputtering process of the rotating target, the target material can rotate around the fixed bar magnet assembly for magnetron sputtering, and the rotating target can rotate 360° to be uniformly etched by magnetron sputtering, so the utilization rate of the rotating target material can reach 95% or more, with good uniformity, large sputtering area, convenient replacement operation, high production efficiency, high target material utilization rate, and unique advantages for deposition on the inner wall of parts. DETAILED DESCRIPTION

[0008] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0009] In this application, the term "and / or" describes the association relationship of associated objects, indicating that there may be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. A and B can be singular or plural. The character " / " generally indicates that the associated objects are in an "or" relationship.

[0010] In this application, "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can all mean: a, b, c, a~b (i.e. a and b), a~c, b~c, or a~b~c, where a, b, and c can be single or multiple, respectively.

[0011] The terms "first" and "second" are used only for descriptive purposes to distinguish objects such as substances from each other, and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. For example, without departing from the scope of the implementation regulations of this application, the first XX may also be referred to as the second XX, and similarly, the second XX may also be referred to as the first XX. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features.

[0012] The terms used in the embodiments of the present application are only for the purpose of describing specific implementation rules, and are not intended to limit the present application. The singular forms "a", "said" and "the" used in the implementation rules of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0013] It should be understood that in the various embodiments of the present application, the size of the serial number of each process does not mean the order of execution, some or all of the steps can be executed in parallel or sequentially, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the implementation regulations of this application.

[0014] The weight of the relevant components mentioned in the embodiment description of the present application can not only refer to the specific content of each component, but also represent the proportional relationship between the weights of the components. Therefore, as long as the content of the relevant components is proportionally enlarged or reduced according to the embodiment description of the present application, it is within the scope disclosed in the embodiment description of the present application. Specifically, the mass described in the embodiment description of the present application can be a mass unit known in the chemical industry such as μg, mg, g, kg, etc.

[0015] Unless otherwise defined, all professional terms used below have the same meanings as those generally understood by those skilled in the art. The professional terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention.

[0016] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in this application can be purchased from the market or prepared by existing methods.

[0017] In a first aspect, the present invention provides a method for preparing a stealth target material for aviation component coating, comprising the following steps: S1, mixing metallic silicon powder, silicon carbide powder, boron nitride powder and carbon powder in a vacuum rolling mixer to obtain a mixture; S2, filling the mixture into a mold, evacuating the mold and cold isostatically pressing the mold to obtain a rough billet, and performing secondary pressing on the rough billet to obtain a green billet of an alloy target; S3, performing vacuum hot pressing sintering on the alloy target green body, and demolding to obtain a crude alloy target; S4, machining the crude alloy target material for annealing, ball-milling the mixture described in S1 and then plasma spraying the mixture onto the surface of the annealed crude alloy target material to obtain a stealth target material for aviation component coating.

[0018] In one embodiment, the added amounts of the metal silicon powder, silicon carbide powder, boron nitride powder and carbon powder in S1 are in the mass ratio of: (2-3): (3-6): (1-3): (1-2).

[0019] In one embodiment, the metal silicon powder S1 is a metal silicon powder having a theoretical density of more than 98% and a Fisher average particle size of 7 μm; the silicon carbide powder is a silicon carbide powder having a theoretical density of more than 99.9% and a Fisher average particle size of 1-7 μm; the boron nitride powder is a boron nitride powder having a theoretical density of more than 99.9% and a Fisher average particle size of 1-7 μm; the carbon powder is a carbon powder having a theoretical density of more than 99.9% and a Fisher average particle size of 1-7 μm.

[0020] In one embodiment, the cold isostatic pressing in S2 is 10-60 MPa; the secondary pressing is 50-200 MPa; and the green density of the alloy target is 60% to 62% of the theoretical density.

[0021] In one embodiment, the process conditions of vacuum hot pressing sintering in S3 are: under argon protective atmosphere, pressure of 20-30 MPa, and temperature of 1500-1980°C.

[0022] In one embodiment, the demoulding process conditions in S3 are: demoulding is performed at 500-600° C. using a high-temperature demoulding process after heat preservation and pressure preservation for 3 hours.

[0023] In one embodiment, the process conditions of annealing in S4 are: placing in a vacuum annealing furnace, heating to 1500-1980° C. and annealing for 3 hours.

[0024] In one embodiment, the process conditions of the ball milling treatment in S4 are: putting the mixture into a ball mill for 3 to 5 hours, and sieving through a 1000 mesh sieve to obtain SSBC spray powder. The SSBC spray powder is a mixed powder of silicon, silicon carbide, boron nitride and carbon.

[0025] In one embodiment, the process conditions of plasma spraying in S4 are: gas flow rate of 400-1200 sccm, pressure of 4-40Kpa, in an inert gas protection atmosphere, each spraying thickness of 0.1mm, and 8-13mm products are obtained; when the target material is a cylindrical target, the outer surface of the cylindrical target liner is sprayed by plasma spraying, and the cylindrical target liner rotates continuously during spraying. The unsintered powder spraying is used to achieve a uniform and loose effect.

[0026] In a second aspect, the present invention applies for a stealth target material for aviation part coating obtained by the preparation method of the first aspect.

[0027] The technical solution of the present application is illustrated below through specific embodiments and comparative examples.

[0028] In order to enable the above implementation details and operations of the present application to be clearly understood by those skilled in the art, and to significantly demonstrate the improved performance of the embodiments of the present application, the above technical solutions are illustrated by means of multiple embodiments below.

[0029] Example 1

[0030] A stealth target material for aviation parts coating and its preparation method: S1. Material preparation: In this example, a total weight of 10.00 kg of alloy is used, and a 2:5:2:1 scheme is preferred. SSBC powder (metal silicon powder accounts for 20%, silicon carbide powder accounts for 50%, boron nitride powder accounts for 20%, and carbon powder accounts for 10%) is configured according to a mass ratio of 2:5:2:1 and put into a vacuum rolling mixer, and fully mixed at a speed of 60r / min. Mixing in a vacuum environment can keep the material dry, remove residual gas, and make the material mixing more uniform; Inspection: Randomly select five points in the mixed material to test the content of metal silicon powder, silicon carbide powder, boron nitride powder and carbon powder, until the content ratio error of metal silicon powder, silicon carbide powder, boron nitride powder and carbon powder at each test point is between 0.01% and 0.03%, and the mixing is completed; S2, taking the mixed material after the inspection and treatment in S1 and filling it into a rubber sleeve equipped with a tubular flexible mold, and applying Zn disulfide powder on the contact surface between the mold and the mixed material, and then sealing the rubber sleeve and evacuating it, and placing the evacuated rubber sleeve on a cold isostatic press, and performing the initial pre-pressing at a pressure of 30 MPa to form a rough blank, and performing the secondary pressing of the obtained rough blank at a pressure of 60 MPa until the density of the green blank reaches 60% to 62% of the theoretical density, and then releasing the pressure to normal pressure to obtain a green blank of the alloy target; S3, placing the alloy target green body in a vacuum hot pressing sintering furnace, hot pressing and sintering under the conditions of argon protection atmosphere, pressure of 30 MPa, and temperature of 1700° C., and demolding at 500° C. using a high temperature demolding process after keeping the temperature and pressure for 3 hours, and cooling to room temperature to obtain a crude alloy target; S4, the alloy target material is machined to the required size, and then placed in a vacuum annealing furnace, heated to 1700℃ for annealing for 3 hours, chemical and physical tests are carried out, and then ultrasonic cleaning is performed to make the target material reach the qualified roughness; the mixed material of S1 is placed in a ball mill for 3 hours, and sieved through a 1000 mesh to obtain SSBC spray powder; inert gas is introduced into the vacuum chamber, the gas flow rate is 600sccm, and the pressure is 12Kpa. Under the inert gas protection atmosphere, the SSBC spray powder is sprayed on the outer surface of the cylindrical target liner by plasma spraying, and the cylindrical target liner rotates continuously during spraying; the spraying thickness is 0.1mm each time, and an 8mm product is obtained. After machining, a 10mm finished product is obtained, and a high-quality SSBC cylindrical rotating target material is obtained. Because the rotating target can rotate 360° and be evenly etched by magnetron sputtering, the utilization rate of the rotating target can reach 95% or more.

[0031] Example 2

[0032] A stealth target material for aviation parts coating and its preparation method: The difference between this embodiment and embodiment 1 is that the ratio of SSBC is different.

[0033] S1. Material preparation: This example uses a total weight of 10.00 kg of alloy, preferably a 2:4:3:1 ratio, and configures SSBC spray powder (metal silicon powder accounts for 20%, silicon carbide powder accounts for 40%, boron nitride powder accounts for 30%, and carbon powder accounts for 10%) according to a mass ratio of 2:4:3:1. Put it into a vacuum rolling mixer and mix it thoroughly at a speed of 60r / min. Mixing in a vacuum environment can keep the material dry, remove residual gas, and make the material mixing more uniform; Inspection: Randomly select five points in the mixed material to test the content of metal silicon powder, silicon carbide powder, boron nitride powder and carbon powder, until the content ratio error of metal silicon powder, silicon carbide powder, boron nitride powder and carbon powder at each test point is between 0.01% and 0.03%, and the mixing is completed; S2, taking the mixed material after the inspection and treatment in S1 and filling it into a rubber sleeve equipped with a tubular flexible mold, and applying Zn disulfide powder on the contact surface between the mold and the mixed material, and then sealing the rubber sleeve and evacuating it, and placing the evacuated rubber sleeve on a cold isostatic press, and performing the initial pre-pressing at a pressure of 30 MPa to form a rough blank, and performing the secondary pressing of the obtained rough blank at a pressure of 60 MPa until the density of the green blank reaches 60% to 62% of the theoretical density, and then releasing the pressure to normal pressure to obtain a green blank of the alloy target; S3, placing the alloy target green body in a vacuum hot pressing sintering furnace, hot pressing and sintering under the conditions of argon protection atmosphere, pressure of 30 MPa, and temperature of 1700° C., and demolding at 500° C. using a high temperature demolding process after keeping the temperature and pressure for 3 hours, and cooling to room temperature to obtain a crude alloy target; S4, the alloy target material is machined to the required size, and then placed in a vacuum annealing furnace, heated to 1700℃ for annealing for 3 hours, chemical and physical tests are carried out, and then ultrasonic cleaning is performed to make the target material reach the qualified roughness; the mixed material of S1 is placed in a ball mill for 3 hours, and sieved through a 1000 mesh to obtain SSBC spray powder; inert gas is introduced into the vacuum chamber, the gas flow rate is 600sccm, and the pressure is 12Kpa. Under the inert gas protection atmosphere, the SSBC spray powder is sprayed on the outer surface of the cylindrical target liner by plasma spraying, and the cylindrical target liner rotates continuously during spraying; the spraying thickness is 0.1mm each time, and an 8mm product is obtained. After machining, a 10mm finished product is obtained, and a high-quality SSBC cylindrical rotating target material is obtained. Because the rotating target can rotate 360° and be evenly etched by magnetron sputtering, the utilization rate of the rotating target can reach 95% or more.

[0034] Example 3

[0035] A stealth target material for aviation parts coating and its preparation method: This embodiment differs from Embodiment 1 in that the proportion of SSBC powder is different.

[0036] S1. Material preparation: In this example, a total weight of 10.00 kg alloy is used, and the preferred 3:3:3:1 scheme is used. SSBC powder (metal silicon powder accounts for 30%, silicon carbide powder accounts for 30%, boron nitride powder accounts for 30%, and carbon powder accounts for 10%) is configured according to the mass ratio of 3:3:3:1 and put into a vacuum rolling mixer, and fully mixed at a speed of 30r / min-90r / min. Mixing in a vacuum environment can keep the material dry, remove residual gas, and make the material mixing more uniform; Inspection: Randomly select five points in the mixed material to test the content of metal silicon powder, silicon carbide powder, boron nitride powder and carbon powder, until the content ratio error of metal silicon powder, silicon carbide powder, boron nitride powder and carbon powder at each test point is between 0.01% and 0.03%, and the mixing is completed; S2, taking the mixed material after the inspection and treatment in S1 and filling it into a rubber sleeve equipped with a tubular flexible mold, and applying Zn disulfide powder on the contact surface between the mold and the mixed material, and then sealing the rubber sleeve and evacuating it, and placing the evacuated rubber sleeve on a cold isostatic press, and performing the initial pre-pressing at a pressure of 30 MPa to form a rough blank, and performing the secondary pressing of the obtained rough blank at 30 MPa until the density of the green blank reaches 60% to 62% of the theoretical density, and then releasing the pressure to normal pressure to obtain a green blank of the alloy target; S3, placing the alloy target green body in a vacuum hot pressing sintering furnace, hot pressing and sintering under the conditions of argon protection atmosphere, pressure of 30 MPa, and temperature of 1700° C., and demolding at 500° C. using a high temperature demolding process after keeping the temperature and pressure for 3 hours, and cooling to room temperature to obtain a crude alloy target; S4. The crude alloy target material obtained in step d is machined to the required size (5-10 mm flat target material), and then placed in a vacuum annealing furnace, heated to 1700°C and annealed for 3 hours; the crude alloy target material is subjected to chemical and physical testing, and then ultrasonically cleaned to ensure that the target material reaches a qualified roughness, thereby obtaining a high-quality SSBC flat target material.

[0037] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0038] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A method for preparing a stealth target material for aviation component coating, characterized in that: The following steps are involved: S1, mixing metallic silicon powder, silicon carbide powder, boron nitride powder and carbon powder in a vacuum rolling mixer to obtain a mixture; S2, filling the mixture into a mold, evacuating the mold and cold isostatically pressing the mold to obtain a rough billet, and performing secondary pressing on the rough billet to obtain a green billet of an alloy target; S3, performing vacuum hot pressing sintering on the alloy target green body, and demolding to obtain a crude alloy target; S4, machining the crude alloy target material for annealing, ball-milling the mixture described in S1 and then plasma spraying the mixture onto the surface of the annealed crude alloy target material to obtain a stealth target material for aviation component coating.

2. The preparation method according to claim 1, characterized in that: The added amounts of the metal silicon powder, silicon carbide powder, boron nitride powder and carbon powder in S1 are in the following mass ratios: (2-3): (3-6): (1-3): (1-2).

3. The preparation method according to claim 1, characterized in that: S1 The metal silicon powder is a metal silicon powder with a theoretical density of more than 98% and a Fisher average particle size of 7μm; the silicon carbide powder is a silicon carbide powder with a theoretical density of more than 99.9% and a Fisher average particle size of 1-7μm; the boron nitride powder is a boron nitride powder with a theoretical density of more than 99.9% and a Fisher average particle size of 1-7μm; the carbon powder is a carbon powder with a theoretical density of more than 99.9% and a Fisher average particle size of 1-7μm.

4. The preparation method according to claim 1, characterized in that: S2: The cold isostatic pressing is 10-60MPa; the secondary pressing is 50-200MPa; the green density of the alloy target is 60% to 62% of the theoretical density.

5. The preparation method according to claim 1, characterized in that: The process conditions of vacuum hot pressing sintering in S3 are: under argon protective atmosphere, pressure of 20-30MPa, and temperature of 1500-1980°C.

6. The preparation method according to claim 1, characterized in that: The demoulding process conditions described in S3 are: demoulding is performed at 500-600° C. using a high-temperature demoulding process after keeping the temperature and pressure for 3 hours.

7. The preparation method according to claim 1, characterized in that: The process conditions of annealing in S4 are: placing in a vacuum annealing furnace, heating to 1500-1980° C. and annealing for 3 hours.

8. The preparation method according to claim 1, characterized in that: S4 The process conditions of the ball milling treatment are: putting the mixture into a ball mill for 3 to 5 hours, and passing through a 1000 mesh sieve to obtain SSBC spray powder.

9. The preparation method according to claim 1, characterized in that: The process conditions of plasma spraying described in S4 are: gas flow rate of 400-1200sccm, pressure of 4-40Kpa, under inert gas protection atmosphere, each spraying thickness is 0.1mm, and 8-13mm product is obtained; when the target material is a cylindrical target, a plasma spraying method is used to spray the outer surface of the cylindrical target liner, and the cylindrical target liner rotates continuously during spraying.

10. A stealth target material for aviation part coating obtained by the preparation method as described in any one of claims 1 to 9.