A coated attitude control thruster body structure and a method for manufacturing the same

Abstract

The application relates to a posture-orbit control thrust chamber body structure with coating protection and a preparation method thereof, and solves the technical problem that the preparation of the coating of a high-thrust high-performance posture-orbit control thrust chamber body is limited by the size of an ion sputtering furnace and the ion sputtering coating with better high-temperature resistance and oxidation resistance cannot be used. The posture-orbit control thrust chamber body structure with coating protection comprises a short body part and an extension section which are sequentially connected; an ion sputtering coating is arranged on the outer wall of the short body part; and a slurry sintering coating is arranged on the outer wall of the extension section, so that the ion sputtering coating can have good high-temperature resistance and oxidation resistance, and the requirement of segmented protection of different regions of the high-thrust high-performance posture-orbit control thrust chamber body can be met. The coating preparation method of the posture-orbit control thrust chamber avoids the problem that the base body of the posture-orbit control thrust chamber is not protected by the coating.

Description

Technical Field

[0001] This invention specifically relates to a body structure of an attitude and orbit control thrust chamber with a protective coating and its preparation method. Background Technology

[0002] Niobium-tungsten alloys, with their excellent high-temperature mechanical properties, have been maturely and widely used in the body of bicomponent attitude control thrust chambers. However, niobium-tungsten alloys themselves have insufficient high-temperature oxidation resistance, making it difficult to maintain their structural integrity under the high-temperature, highly oxidizing combustion atmosphere of bicomponent systems. Therefore, it is necessary to spray a high-temperature anti-oxidation coating on the surface of the niobium-tungsten alloy substrate to protect the niobium-tungsten alloy matrix itself from damage by highly oxidizing combustion gases.

[0003] Based on differences in coating characteristics and preparation processes, commonly used niobium-tungsten alloy coatings are mainly divided into two categories: vacuum ion sputtering coatings and slurry sintering coatings. Vacuum ion sputtering coatings contain high-melting-point molybdenum and have a dense microstructure, exhibiting excellent high-temperature resistance. However, the preparation process is complex and costly, and large-scale body coatings cannot be prepared due to limitations in the size of the vacuum ion sputtering furnace. Slurry sintering coatings have a simple preparation process, a short cycle time, and are not limited by equipment capabilities. However, slurry sintering coatings do not have the same high-temperature resistance as vacuum ion sputtering coatings.

[0004] Currently, domestic attitude and orbit control thrust chambers all use one type of coating to protect the niobium-tungsten alloy body. The vast majority use slurry sintering coatings, with only a few thrust chambers with a thrust level of less than 200N using vacuum ion sputtering coatings. Due to the size limitations of ion sputtering furnaces, it is not possible to fabricate the full-size body of a high-performance thrust chamber with a large area ratio and a thrust level greater than 1000N using vacuum ion sputtering coatings. Therefore, the high-temperature resistance and oxidation resistance advantages of ion sputtering coatings cannot be used in this type of thrust chamber, limiting the improvement and potential tapping of the specific impulse performance and overall reliability of high-performance thrust chambers.

[0005] For high-thrust, high-performance attitude and orbit control thrust chambers, a short body and an extension section are typically welded together. The weld is usually a parallel structure perpendicular to the axis of the body, with a large weld penetration. This requires significant welding energy to fully penetrate the joint, but the high welding energy poses a risk of cracking defects in the niobium-tungsten alloy matrix. To ensure welding quality, the misalignment at the joint between the short body and the extension section must be controlled within a certain range. However, since the weld is perpendicular to the axis of the body and there is no self-aligning positioning mechanism, special tooling is required to ensure that the misalignment meets the welding requirements, making the process quite challenging. Summary of the Invention

[0006] The purpose of this invention is to solve the technical problem that the preparation of the coating of the body of a high-thrust, high-performance attitude and orbit control thrust chamber is limited by the size of the ion sputtering furnace, making it impossible to utilize ion sputtering coatings with better high-temperature resistance and oxidation resistance. The invention provides a body structure of the attitude and orbit control thrust chamber with coating protection and its preparation method.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0008] A thrust chamber body structure with a protective coating, the thrust chamber body comprising a short body and an extension section connected in sequence;

[0009] Its special feature is:

[0010] The first connecting end face of the short body near the extension section is perpendicular to the outer wall of the short body.

[0011] The extension section is provided with a second connecting end face that mates with the first connecting end face; the first connecting end face and the second connecting end face are welded together;

[0012] An ion sputtering coating is provided on the outer wall of the short body section;

[0013] The outer wall of the extension section is provided with a slurry sintering coating.

[0014] Furthermore, at the welding joint between the outer wall of the short section and the outer wall of the extension section, the slurry sintering coating partially covers the ion sputtering coating.

[0015] Furthermore, the attitude and orbit control thrust chamber is a large-size, high-area-ratio attitude and orbit control thrust chamber with a thrust level greater than 1000N.

[0016] Furthermore, the ion sputtering coating is a niobium-tungsten alloy coating;

[0017] The slurry sintering coating is a niobium-tungsten alloy coating.

[0018] Meanwhile, the present invention also provides a method for preparing the above-mentioned attitude and orbit control thrust chamber body structure with coating protection, which is characterized by including the following steps:

[0019] 1) An ion-sputtered coating is prepared on the outer wall of the short section;

[0020] 2) Weld the short section to the uncoated extension section;

[0021] 3) After the short body and the extension section are welded, a slurry sintering coating is prepared on the outer wall of the extension section. The slurry sintering coating extends to the welding joint position and covers part of the ion sputtering coating of the short body.

[0022] Furthermore, in step 2), the weld between the short body and the extension is a vertical weld; the welding is performed using electron beam welding.

[0023] Further, in step 1), the ion sputtering coating is a niobium-tungsten alloy coating.

[0024] Furthermore, in step 3), the slurry sintering coating is a niobium-tungsten alloy coating.

[0025] Compared with the prior art, the beneficial effects of the technical solution of the present invention are:

[0026] 1) The attitude and orbit control thrust chamber body structure with coating protection of the present invention uses two different coatings in different sections according to the differences in gas characteristics and protection requirements of different parts of the attitude and orbit control thrust chamber body connection structure. Ion sputtering coating is used in the short body section with higher requirements for high temperature resistance and oxidation resistance, and slurry sintering coating is used in the extended section where the gas temperature is relatively low but oxidation erosion is significant. The attitude and orbit control thrust chamber body adopts two coatings in a segmented protection scheme, which can not only give full play to the excellent high temperature resistance and oxidation resistance of ion sputtering coating, but also meet the needs of segmented protection of different areas of the body of high thrust and high performance attitude and orbit control thrust chamber. Moreover, the preparation of the protective coating of attitude and orbit control thrust chamber is not limited by the size of ion sputtering furnace, which solves the problem that high thrust and high performance attitude and orbit control thrust chamber cannot use ion sputtering coating with better high temperature resistance and oxidation resistance.

[0027] 2) The attitude and orbit control thrust chamber body structure with coating protection of the present invention has a slurry sintering coating covering an ion sputtering coating at the welding and docking position of the outer wall of the short body and the outer wall of the extension section, which makes the body protection of the attitude and orbit control thrust chamber more robust and avoids the problem of local lack of coating protection of the attitude and orbit control thrust chamber substrate.

[0028] 3) The attitude control thrust chamber body structure with coating protection of the present invention can be extended to attitude control thrust chambers suitable for full-size coating ion sputtering coating, reducing the preparation cost of ion sputtering coating. Since the area of ​​the extension section accounts for a large proportion of the attitude control thrust chamber body, the coating preparation cost can be reduced by 50% to 80% after adopting the attitude control thrust chamber with different coatings for segmented protection according to the present invention.

[0029] 4) The attitude control thrust chamber body structure with coating protection of the present invention has a vertical weld between the short body and the extension section. The self-centering effect of the vertical weld reduces the misalignment of the welding part and the process difficulty. The vertical weld also reduces the actual weld penetration depth, thereby significantly reducing the welding heat input and preventing crack defects in the niobium-tungsten alloy substrate.

[0030] 5) The present invention provides a method for preparing the body structure of the attitude and orbit control thrust chamber with coating protection. The body of the attitude and orbit control thrust chamber adopts two coatings. First, an ion sputtering coating is prepared on the short body and connected to the uncoated extension section by electron beam welding. After the connection is completed, a slurry sintering coating is prepared on the extension section. In the transition area between the two coatings, the ion sputtering coating is covered by the slurry sintering coating, thus avoiding the absence of coating protection on the substrate of the attitude and orbit control thrust chamber. Attached Figure Description

[0031] Figure 1 A schematic diagram of the body structure of the attitude control thrust chamber with protective coating according to the present invention;

[0032] Figure 2 for Figure 1 A magnified view of a portion of point A in the middle;

[0033] Figure 3 A schematic diagram of the weld structure of the short body and the extended section of the attitude control thrust chamber body structure, wherein B represents the vertical weld of the present invention, C represents the conventional oblique weld, b is the penetration depth of the vertical weld of the attitude control thrust chamber body, c is the penetration depth of the conventional oblique weld, and α is the angle between the penetration depth of the vertical weld b and the penetration depth c of the conventional oblique weld.

[0034] The attached figures are labeled as follows:

[0035] 1-Short body, 2-Extension section, 3-Ion sputtering coating, 4-Slurry sintering coating. Detailed Implementation

[0036] like Figure 1 , Figure 2 As shown, a thrust chamber body structure with a protective coating is disclosed, wherein the thrust chamber body includes a short body 1 and an extension section 2 connected in sequence; a first connecting end face of the short body 1 near the end of the extension section 2 is perpendicular to the outer wall of the short body 1; the extension section 2 is provided with a second connecting end face that mates with the first connecting end face; the first connecting end face and the second connecting end face are welded; an ion sputtering coating 3 is provided on the outer wall of the short body 1; and a slurry sintering coating 4 is provided on the outer wall of the extension section 2.

[0037] Preferably, at the weld joint between the outer wall of the short body 1 and the outer wall of the extension section 2, the slurry sintering coating 4 partially covers the ion sputtering coating 3. The weld between the short body 1 and the extension section 2 is a vertical weld, which is perpendicular to the body axis of the attitude control thrust chamber.

[0038] In this embodiment, the attitude control thrust chamber is a large-size, high-area-ratio attitude control thrust chamber with a thrust level greater than 1000N. The ion sputtering coating 3 is a niobium-tungsten alloy coating; the slurry sintering coating 4 is a niobium-tungsten alloy coating.

[0039] Meanwhile, the present invention also provides a method for preparing the above-mentioned attitude and orbit control thrust chamber body structure with coating protection, comprising the following steps:

[0040] 1) First, the substrate of the short body 1 is machined from niobium-tungsten alloy rods. A process section is reserved within a range of 3 mm to 5 mm along the length of the combustion chamber at the first connecting end face. The inner wall thickness of the process section is 0.3 mm to 1 mm thicker than the side wall thickness of the short body 1. Then, an ion sputtering coating 3 is prepared on the outer wall of the short body 1 with the process section; preferably, the ion sputtering coating 3 is a niobium-tungsten alloy coating.

[0041] 2) After the ion sputtering coating 3 is prepared, the rework section is machined and the first mating end face is machined. The dimensions after rework are consistent with the dimensions required for the short body 1. After rework, the inner and outer walls of the original process section and the first mating end face are without the ion sputtering coating 3. This area is called the mating area. The area with and without the ion sputtering coating is called the travel boundary line.

[0042] The required extension section 2 profile is machined from niobium-tungsten alloy rods using a spinning process. Then, the second mating end face is machined to fit the actual dimensions of the first mating end face. The short body 1, coated with ion sputtering layer 3, is assembled with the extension section 2, ensuring that the misalignment between the short body 1 and the extension section 2 is no greater than 0.1 mm and the mating gap is no greater than 0.1 mm. The short body 1 and the uncoated extension section 2 are then welded together using electron beam welding. Preferably, the weld between the short body 1 and the extension section 2 is a vertical weld.

[0043] 3) After the short body 1 and the extension section 2 are welded, a slurry sintering coating 4 is prepared on the outer wall of the extension section 2. The slurry sintering coating 4 extends to the welding butt joint position, covering part of the ion sputtering coating 3 of the short body 1. After spraying, it is sintered at high temperature in a sintering furnace to complete the preparation of the slurry sintering coating 4. Preferably, the slurry sintering coating 4 is a niobium-tungsten alloy coating to ensure that the surface of the niobium-tungsten alloy substrate at the transition position of the two coatings is protected by the coating. During the sintering process, the slurry sintering coating 4 near the travel boundary line crosses the travel boundary line under the action of surface tension and flows into the area of ​​the ion sputtering coating 3, forming a transition zone where the slurry sintering coating 4 covers the ion sputtering coating 3. This ensures that the niobium-tungsten alloy substrate of the attitude control thrust chamber body is covered by the coating, and the length of the transition zone is 2 mm to 10 mm.

[0044] Based on the differences in gas characteristics and protection requirements in different parts of the attitude and orbit control thrust chamber, this invention uses two different coatings in different sections. The short section 1 of the attitude and orbit control thrust chamber mainly completes propellant injection, atomization, and combustion, and is the main area of ​​combustion organization. It has high requirements for the high temperature resistance and oxidation resistance of the coating. Therefore, an ion sputtering coating 3 with stronger high temperature resistance and oxidation resistance is prepared in the short section 1. The extended section 2 of the attitude and orbit control thrust chamber mainly completes high temperature gas expansion and acceleration. The gas temperature is lower than that in the short section 1, but the oxidation resistance of the coating is still required to be high. Therefore, a slurry sintering coating 4 is prepared in the extended section 2.

[0045] In the shorter section 1, where higher temperature resistance and oxidation resistance are required, an ion sputtering coating 3 is used. In the extended section 2, where the gas temperature is relatively low but oxidation erosion is significant, a slurry sintering coating 4 is used. The attitude and orbit control thrust chamber body adopts two coating segment protection schemes, which can give full play to the excellent high temperature resistance and oxidation resistance of the ion sputtering coating 3, and meet the requirements of segment protection for different areas of the high-thrust, high-performance thrust chamber body. At the same time, at the joint between the shorter section 1 and the extended section 2, a wedge-shaped weld structure is formed with the outer surface perpendicular to the attitude and orbit control thrust chamber to reduce the cumulative process deviation of wall misalignment and welding heat input, and prevent crack defects in the niobium-tungsten alloy matrix.

[0046] like Figure 3 As shown, the welds of the short body 1 and the extension section 2 are perpendicular to the axis of the attitude control thrust chamber. Compared with the vertical welded structure, the weld penetration depth at the traditional oblique weld C is 2.12 mm. This can be reduced from the penetration depth c of the traditional weld to the penetration depth b of the vertical weld B. α is the angle between the vertical weld b and the penetration depth c of the traditional oblique weld, which is 34°, resulting in b = c(1-cosα) = 1.6 mm. By using the method of this invention to change the traditional oblique weld C to a vertical weld B, the weld penetration depth is reduced by 20.7%, preventing crack defects in the niobium-tungsten alloy matrix due to high welding heat input. Simultaneously, the docking positions of the short body 1 and the extension section 2 are both perpendicular to the outer surface of the attitude control thrust chamber, improving alignment and reducing the controllability of wall misalignment.

Claims

1. A thrust chamber body structure with a coating protection, the thrust chamber body comprising a short body (1) and an extension section (2) connected in sequence. Its features are: The first connecting end face of the short body (1) near the end of the extension section (2) is perpendicular to the outer wall of the short body (1); The extension section (2) is provided with a second connecting end face that mates with the first connecting end face; the first connecting end face is welded to the second connecting end face; An ion sputtering coating (3) is provided on the outer wall of the short body (1); The outer wall of the extension section (2) is provided with a slurry sintering coating (4); At the welding joint between the outer wall of the short section (1) and the outer wall of the extension section (2), the slurry sintering coating (4) covers part of the ion sputtering coating (3).

2. The attitude control thrust chamber body structure with coating protection according to claim 1, characterized in that: The attitude and orbit control thrust chamber is a large-size, high-area-ratio attitude and orbit control thrust chamber with a thrust level greater than 1000N.

3. The attitude control thrust chamber body structure with coating protection according to claim 2, characterized in that: The ion sputtering coating (3) is a niobium-tungsten alloy coating; The slurry sintering coating (4) is a niobium-tungsten alloy coating.

4. A method of manufacturing a protective coated attitude control thruster body structure according to any one of claims 1 to 3, characterized in that Includes the following steps: 1) An ion sputtering coating (3) is prepared on the outer wall of the short body (1); 2) Weld the short body (1) to the uncoated extension (2); 3) After the short body (1) and the extension (2) are welded, a slurry sintering coating (4) is prepared on the outer wall of the extension (2). The slurry sintering coating (4) extends to the welding butt joint position and covers part of the ion sputtering coating (3) of the short body (1).

5. The method for preparing a body structure of an attitude and orbit control thrust chamber with a protective coating according to claim 4, characterized in that: In step 2), the weld between the short body (1) and the extension section (2) is a vertical weld; the welding is performed by electron beam welding.

6. The method for preparing a body structure of an attitude and orbit control thrust chamber with a protective coating according to claim 5, characterized in that: In step 1), the ion sputtering coating (3) is a niobium-tungsten alloy coating.

7. The method for preparing a body structure of an attitude and orbit control thrust chamber with a protective coating according to claim 6, characterized in that: In step 3), the slurry sintering coating (4) is a niobium-tungsten alloy coating.

Images