阅读说明：本技术 一种火箭发动机推力室夹壁结构及其制造方法 (Rocket engine thrust chamber double-wall structure and manufacturing method thereof ) 是由 谢迎春 黄仁忠 黄健 王皓杰 殷硕 邓春明 邓畅光 王昊 于 2021-10-12 设计创作，主要内容包括：本发明公开了一种火箭发动机推力室夹壁结构及其制造方法,涉及航空航天制造技术领域。火箭发动机推力室夹壁结构的制造方法,采用固态增材制造的方法,在铜基内衬结构上沉积镍基合金粉末,形成推力室夹壁结构；其中,沉积时对镍基合金粉末的加热温度为500-1000℃。采用低温固态增材制造的方法是采用氛围环境对粉末颗粒进行加速,使得粉末颗粒被加速到极高的速度,在加速的过程中不断对粉末颗粒进行加热,加热温度低于粉末的熔点以下,使其软化但不熔化,软化的粉末颗粒高速撞击到基底表面通过强烈塑形变形沉积形成致密度高的夹壁结构,沉积效率高。(The invention discloses a rocket engine thrust chamber double-wall structure and a manufacturing method thereof, and relates to the technical field of aerospace manufacturing. The manufacturing method of the sandwich wall structure of the thrust chamber of the rocket engine adopts a solid additive manufacturing method to deposit nickel-based alloy powder on a copper-based lining structure to form the sandwich wall structure of the thrust chamber; wherein the heating temperature for the nickel-based alloy powder during deposition is 500-1000 ℃. The method for manufacturing the low-temperature solid additive adopts an atmosphere environment to accelerate powder particles to extremely high speed, the powder particles are continuously heated in the accelerating process, the heating temperature is lower than the melting point of the powder to soften the powder particles but not melt the powder particles, the softened powder particles impact the surface of a substrate at high speed to form a high-density sandwich wall structure through strong plastic deformation deposition, and the deposition efficiency is high.)

1. A manufacturing method of a thrust chamber sandwich wall structure of a rocket engine is characterized in that a solid additive manufacturing method is adopted, nickel-based alloy powder is deposited on a copper-based lining structure, and the thrust chamber sandwich wall structure is formed;

wherein the heating temperature for the nickel-based alloy powder during deposition is 500-1000 ℃.

2. The manufacturing method according to claim 1, characterized by comprising the steps of:

forming a lining structure: processing the shape of the lining base material to obtain an inner lining layer which is in accordance with the shape of the lining, forming a gully structure on the inner lining layer, and filling the gully structure with aluminum material;

and (3) forming a sandwich wall structure: depositing nickel-based alloy powder on the lining structure to form an outer shell structure by adopting a solid additive manufacturing method, and then soaking the integral component by adopting an alkaline solution so as to enable the alkaline solution to react with the aluminum material to form a cooling pipeline;

preferably, the gully structure is a groove-shaped structure extending from one end to the other end, and the groove-shaped structure is distributed in a plurality of equal parts.

3. The manufacturing method according to claim 2, wherein the lining base material is a copper alloy material.

4. The production method according to claim 2, wherein the alkaline solution is at least one selected from a sodium hydroxide solution and a potassium hydroxide solution.

5. The manufacturing method according to claim 2, wherein the aluminum material is at least one selected from an aluminum ingot and an aluminum alloy.

6. The manufacturing method according to claim 1 or 2, characterized in that the particle size of the nickel-based alloy powder is 10-80 μm, preferably 10-30 μm.

7. The manufacturing method according to claim 6, wherein the gas for depositing the nickel-based alloy powder is preheated, and the nickel-based alloy powder is sprayed under heating;

preferably, the preheating temperature of the accelerated gas for deposition is 800-;

preferably, the heating temperature of the nickel-based alloy powder is controlled to be 700-800 ℃ during the deposition process.

8. The manufacturing method according to claim 7, wherein the powder feeding amount is controlled to be 80 to 220g/min during the deposition, the distance between the nozzle and the substrate during the deposition is 10 to 50mm, and the scanning speed of the nozzle is 50 to 500 mm/s.

9. The method as claimed in claim 8, wherein the powder feeding amount is controlled to be 150-200g/min during the deposition process, the distance between the nozzle and the substrate during the deposition process is 25-40mm, and the scanning speed of the nozzle is 100-200 mm/s.

10. A rocket engine thrust chamber double-walled structure produced by the method of any one of claims 1 to 9.

Technical Field

The invention relates to the technical field of aerospace manufacturing, in particular to a rocket engine thrust chamber double-wall structure and a manufacturing method thereof.

Background

The thrust chamber is a component for mixing and burning fuel in the rocket engine, and can generate high-temperature and high-pressure fuel gas in the burning process, so that chemical energy is converted into heat energy, and then the heat energy is further converted into kinetic energy to generate thrust. The structural design and material selection of the thrust chamber is important for efficient heat removal and proper performance. The existing rocket engine thrust chamber adopts a regenerative cooling structure, and the structure comprises a cooling jacket formed by an inner wall and an outer wall, and about 360 cooling grooves are formed.

The manufacturing processes of the conventional thrust chamber regenerative cooling structure are mainly a welding process and 3D printing. The welding process is usually long in preparation period, the traditional welding technology cannot weld the lining and the shell well due to the limitation of the materials of the lining and the shell, the quality of different parts of the parts is difficult to control consistently, the heat-conducting property of the thrust chamber is difficult to guarantee, products prepared by the traditional welding process are easy to crack and damage in the high-speed and high-strength operation process, the service life is short, and the preparation cost is high. Because 3D printing meets the characteristics of complex component preparation, low cost and high production efficiency, a plurality of space companies utilize the 3D printing technology to prepare the engine thrust chamber at present.

However, the engine cavity wall and internal cooling flow channel surfaces made by SLM-based 3D printing technology are typically rough, which causes heat transfer to increase and reduces the flow efficiency of the cooling medium; the solution to the above problems is mainly improved by improving the printing process and performing post-processing after printing is completed, so that the manufacturing difficulty and the manufacturing cost are also greatly increased. Meanwhile, the existing 3d printing technology cannot finish additive manufacturing of a bimetal and double-layer structural member, and for the lining copper alloy, the manufacturing of an engine thrust chamber with an outer layer nickel-based alloy and a sandwich structure cannot be finished.

Therefore, it is desirable to provide a method for forming a rocket engine thrust chamber sandwich wall structure with high efficiency and low cost, which solves the above-mentioned problems in the prior art.

Disclosure of Invention

The invention aims to provide a rocket engine thrust chamber double-wall structure and a manufacturing method thereof, and aims to remarkably improve the manufacturing efficiency and reduce the manufacturing cost.

The invention is realized by the following steps:

in a first aspect, the invention provides a manufacturing method of a thrust chamber sandwich wall structure of a rocket engine, which adopts a solid additive manufacturing method to deposit nickel-based alloy powder on an inner lining structure to form the thrust chamber sandwich wall structure; wherein the heating temperature for the nickel-based alloy powder during deposition is 500-1000 ℃.

In a second aspect, the present invention provides a rocket engine thrust chamber double-walled structure prepared by the manufacturing method of the foregoing embodiment.

The invention has the following beneficial effects: the inventor creatively adopts a solid additive manufacturing method to deposit nickel-based alloy powder on an inner lining structure to form a thrust chamber sandwich wall structure, and the heating temperature of the nickel-based alloy powder during deposition is 500-1000 ℃. The method for manufacturing the low-temperature solid additive adopts an atmosphere environment to accelerate powder particles to extremely high speed, the powder particles are continuously heated in the accelerating process, the heating temperature is lower than the melting point of the powder to soften the powder but not melt the powder, the speed of the powder particles impacting on a substrate is extremely high and soft, a high-density sandwich wall structure is formed by deposition, and the deposition efficiency is extremely high.

In the traditional welding process, if the inner liner is made of copper alloy materials, the shell is made of nickel-based alloy materials, welding is difficult, and the bonding strength is poor.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

FIG. 1 is a structural diagram of a double-walled structure of a thrust chamber of a rocket engine provided in an embodiment of the present application;

FIG. 2 is a block diagram of a rocket thrust chamber liner provided in an embodiment of the present application;

FIG. 3 is a schematic structural view of a rocket thrust chamber filled with aluminum according to an embodiment of the present disclosure;

FIG. 4 is a schematic view of the overall structure of a rocket thrust chamber provided in an embodiment of the present application;

fig. 5 is a schematic diagram of a manufacturing method of a rocket engine thrust chamber double-wall structure according to an embodiment of the application.

Icon: 001-powdered raw material; 002-base body; 101-powder feeding pipe; 102-an acceleration box; 103-heating box.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

The thrust chamber of the rocket engine is to mix and burn fuel to generate high-temperature and high-pressure fuel gas, the burning temperature of the throat part of the combustion chamber is as high as 3500 ℃, the temperature of the inner wall of the combustion chamber exceeds 1000 ℃, any metal material is nearly melted at the temperature, so the material needs to be corroded by the corrosive high-pressure and high-speed fuel gas, and the thrust chamber needs to meet the requirements of high strength and high hardness.

The structure of the thrust chamber is shown in figure 1, the thrust chamber comprises a combustion chamber, a contraction section and a nozzle throat part, the sectional view is shown in the right drawing of figure 1, the thrust chamber comprises an inner lining, an outer casing and a cooling channel positioned between the inner lining and the outer casing, and the overall structure of the thrust chamber is similar to that of a matched thrust pipe.

The inventor improves the manufacturing method of the thrust chamber, the lining structural material copper alloy is prepared, and the shell structural material nickel-based alloy powder is formed by solid deposition. Copper alloys are the best choice for liner construction materials because of their good thermal conductivity, creep (deformation) resistance, and high temperature strength, as well as their economic benefits. The nickel-based alloy powder has good ductility and impact toughness as well as high-temperature creep resistance, high-temperature strength and high heat conductivity, and the nickel-based alloy material can well meet the service performance requirement of the shell due to the fact that the shell needs higher strength and excellent heat conductivity. The inventor endows the final thrust chamber product with high thermal conductivity, high strength and hardness by improving the materials of the inner lining and the outer shell and matching with a solid additive manufacturing method. Because the deposition efficiency is high, the production efficiency can be greatly improved, the powder particles are directly subjected to solid deposition, excessive pretreatment and aftertreatment operations are not needed, the preparation process is simple, and the preparation cost is low.

The embodiment of the invention provides a manufacturing method of a sandwich wall structure of a thrust chamber of a rocket engine. In the actual preparation process, the method comprises the following steps:

s1 formation of lining structure

The shape of the lining base material is processed to obtain the lining layer which is in accordance with the shape of the lining, a gully structure is formed on the lining layer as shown in figure 2, then the gully structure is filled with aluminum material so as to enable the surface to be flush without influencing the deposition of the outer shell, and the formed lining structure is shown in figure 3.

In particular, the lining substrate may be a copper alloy material, such as chromium zirconium copper, bronze, brass, or the like. The inner liner layer is processed by a conventional method to obtain the inner liner layer meeting the shape requirement, and in order to form a cooling channel, a gully structure is dug in the inner liner layer, wherein the gully structure can be a groove-shaped structure extending from one end to the other end, and the groove-shaped structures are a plurality of and are uniformly distributed on the surface of the inner liner layer.

Specifically, the aluminum material is at least one selected from aluminum ingots and aluminum alloys, and the cooling channels are formed by reacting aluminum in the aluminum material with an alkaline solution.

S2 formation of a double-walled structure

The solid additive manufacturing method is adopted, nickel-based alloy powder is deposited on the lining structure to form a shell structure, and then the whole component is soaked by alkaline solution, so that the alkaline solution reacts with the aluminum material to form a cooling pipeline, as shown in fig. 4.

Specifically. The soaking time is only required to ensure that the alkaline solution and the aluminum material are fully reacted, and a gully structure is shown after the reaction. The alkaline solution is at least one selected from sodium hydroxide solution and potassium hydroxide solution, and can be single alkaline solution or mixed solution.

Specifically, the apparatus used in the solid additive manufacturing method according to the embodiment of the present invention includes a powder feeding tube 101, an acceleration box 102, and a heating box 103 as shown in fig. 5, the powder feeding tube 101 accelerates the powder to a high speed in the acceleration box 102, and the powder raw material 001 heated by the heating box 103 is ejected from the nozzle onto the base 002. By adopting the solid additive manufacturing method, the powder particles are accelerated through the atmosphere environment, so that the powder particles are accelerated to an extremely high speed (such as supersonic speed), the speed of the powder particles impacting on the substrate is extremely high, and the formed product is compact and has low porosity. In the spraying process, the impact of the subsequent particles plays a role in tamping a coating formed by the previous particles, and the volume shrinkage of the particles is not obvious, so that the product has higher hardness and strength.

In the specific operation process, the nickel-based alloy powder and the deposition gas are preheated, and then the nickel-based alloy powder is deposited under the heating condition. It should be noted that, since the nickel-based alloy powder is not easy to deform, the powder particles are continuously heated in the acceleration process, the heating temperature is lower than the melting point of the powder, so that the powder particles are softened but not melted, the speed of the powder particles impacting on the substrate is extremely high and soft, the wall-sandwiched structure formed by deposition is compact and high in efficiency, and the problem of low bonding strength of the traditional welding process is solved.

In some embodiments, the preheating temperature of the deposition accelerating gas is 800-1200 deg.C, such as 800 deg.C, 900 deg.C, 1000 deg.C, 1100 deg.C, 1200 deg.C, etc. By preheating the powder and the gas, the method is beneficial to reducing the moisture in the powder, increasing the flowability of the powder and improving the acceleration speed and the deposition efficiency of particles.

In some embodiments, the heating temperature of the nickel-based alloy powder during deposition is controlled to be 500-; more preferably 700 ℃ and 800 ℃. The heating temperature is controlled within the range, so that the powder can be softened without melting, the prepared product is not oxidized and changed in phase, and the hardness and the strength of the prepared product are improved. If the heating temperature is too high, the powder particles are melted, the melted powder particles and ambient air can generate oxidation reaction, and a coating formed by deposition can also generate phase change reaction, so that the performance of the prepared coating is poor; if the heating temperature is too low, the powder particles cannot be well softened, the softening effect is poor, and the deposition efficiency and the coating performance are further influenced.

Alternatively, the heating temperature may be 500 ℃, 600 ℃, 700 ℃, 800 ℃, 900 ℃, 1000 ℃, or the like.

In some embodiments, the particle size of the nickel-based alloy powder is 10-80 μm, preferably 10-30 μm. By controlling the particle size of the nickel-based alloy powder within the above range, the powder can be accelerated to a higher speed when being re-accelerated, and the powder can strike a substrate to be deposited in a solid state. If the size of the powder is too large, the accelerating effect is too poor, and effective deposition cannot be realized; if the powder is too small in size, it is affected by the compression shock wave and cannot be efficiently deposited. Only when the particle size of the nickel-based alloy powder is controlled within the above range, the powder can be continuously tamped to impact the matrix and the previously deposited powder particles, so that the particle volume is shrunk, the compactness of the prepared sample is continuously increased, and the hardness and the strength of the prepared sample are continuously increased.

Alternatively, the particle size of the nickel-based alloy powder may be 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, or the like.

Furthermore, in the deposition process, the powder feeding amount is controlled to be 80-220g/min, the distance between the nozzle and the substrate during deposition is 10-50mm, and the scanning speed of the nozzle is 50-500 mm/s. The powder feeding amount, the distance between the nozzle and the base body, the scanning speed of the nozzle and other factors influence the performance of the product, and through controlling the parameters, the parameters are matched with each other, so that the powder deposition efficiency can be improved, and the strength and the hardness of the product are improved.

Specifically, the powder feeding amount can be 80g/min, 100g/min, 120g/min, 140g/min, 160g/min, 180g/min, 200g/min, 220g/min, and the like; the spraying pitch may be 10mm, 20mm, 30mm, 40mm, 50mm, etc., the nozzle scanning rate may be 50mm/s, 100mm/s, 150mm/s, 200mm/s, 250mm/s, 300mm/s, 350mm/s, 400mm/s, 450mm/s, 500mm/s, etc., and the powder feeding amount, the spraying pitch, the nozzle scanning rate may be any value between the above adjacent point values.

In order to further improve the comprehensive properties of the product such as strength, hardness and the like, the optimization of each parameter is carried out. In the preferred embodiment, the powder feeding amount is controlled to be 150-.

In particular, it is preferred that the distance between the nozzle and the substrate during deposition be controlled to be within the above range, and that the distance of spraying be such that the metal powder ejected from the nozzle forms a dense, low porosity product on the substrate. If the spraying distance is too small, the acting force of the sprayed metal powder impacting on the substrate is large, the nozzle is easy to damage, and the maximum deposition speed cannot be reached; if the spraying distance is too large, the speed of the sprayed metal powder impacting the substrate is low, and the metal powder cannot be effectively deposited to form a product.

The embodiment of the invention also provides a rocket engine thrust chamber sandwich wall structure, which is prepared by the preparation method, and the prepared rocket thrust chamber has the advantages of high heat conductivity, high strength and high hardness, and is high in preparation efficiency and low in preparation cost.

The features and properties of the present invention are described in further detail below with reference to examples.

Example 1

The embodiment provides a manufacturing method of a rocket engine thrust chamber double-wall structure, which comprises the following steps:

the shape of the copper alloy material is processed to obtain the lining layer which is in accordance with the shape of the lining, a groove-shaped gully structure is formed on the lining layer as shown in figure 2, and then the gully structure is filled with Al6061 aluminum alloy so as to enable the surface to be flush, and the formed lining structure is shown in figure 3.

Using a solid additive manufacturing method, nickel-based alloy powder is deposited on the lining structure to form the shell structure, and then the monolithic component is soaked with supersaturated sodium hydroxide solution to react the sodium hydroxide solution with the aluminum material to form the cooling conduit, as shown in fig. 4. The deposition process comprises the steps of preheating nickel-based alloy powder and deposition gas, starting a spraying device, depositing the nickel-based alloy powder under a heating condition, and scanning back and forth on an inner lining structure to form a shell. The parameters of deposition were as follows: the particle size of the nickel-based alloy powder is 10-30 μm, the preheating temperature of the accelerating gas for deposition is 800 ℃, the heating temperature of the powder is 500 ℃, the scanning speed is 200mm/s, the powder feeding amount is 300g/min, and the distance from a nozzle to a substrate is set to be 20mm during spraying.

Example 2

The embodiment provides a manufacturing method of a rocket engine thrust chamber double-wall structure, which is different from the embodiment 1 only in that: the particle size of the nickel-based alloy powder is 10-30 μm, the preheating temperature of the accelerating gas for deposition is 900 ℃, the heating temperature of the powder is 600 ℃, the scanning speed is 400mm/s, the powder feeding amount is 400g/min, and the distance from a nozzle to a substrate is set to be 30mm during spraying.

Example 3

The embodiment provides a manufacturing method of a rocket engine thrust chamber double-wall structure, which is different from the embodiment 1 only in that: the particle size of the nickel-based alloy powder is 10-30 μm, the preheating temperature of the accelerating gas for deposition is 1000 ℃, the heating temperature of the powder is 700 ℃, the scanning speed is 600mm/s, the powder feeding amount is 400g/min, and the distance from a nozzle to a substrate is set to be 40mm during spraying.

Example 4

The embodiment provides a manufacturing method of a rocket engine thrust chamber double-wall structure, which is different from the embodiment 1 only in that: the particle size of the nickel-based alloy powder is 10-30 μm, the preheating temperature of the accelerating gas for deposition is 1100 ℃, the heating temperature of the powder is 800 ℃, the scanning speed is 200mm/s, the powder feeding amount is 300g/min, and the distance from a nozzle to a substrate is set to be 30mm during spraying.

Example 5

The embodiment provides a manufacturing method of a rocket engine thrust chamber double-wall structure, which is different from the embodiment 1 only in that: the particle size of the nickel-based alloy powder is 10-30 μm, the preheating temperature of the accelerating gas for deposition is 800 ℃, the heating temperature of the powder is 900 ℃, the scanning speed is 300mm/s, the powder feeding amount is 400g/min, and the distance from a nozzle to a substrate is set to be 40mm during spraying.

Example 6

The embodiment provides a manufacturing method of a rocket engine thrust chamber double-wall structure, which is different from the embodiment 1 only in that: the particle size of the nickel-based alloy powder is 10-30 μm, the preheating temperature of the accelerating gas for deposition is 1200 ℃, the heating temperature of the powder is 1000 ℃, the scanning speed is 500mm/s, the powder feeding amount is 500g/min, and the distance from a nozzle to a substrate is set to be 50mm during spraying.

Comparative example 1

The comparative example provides a manufacturing method of a rocket engine thrust chamber double-wall structure, which is different from the embodiment 1 only in that: the scanning rate in the deposition process was 600mm/s, and the powder feed amount was 500 g/min.

Comparative example 2

The present comparative example provides a method for manufacturing a thrust chamber sandwich wall structure of a rocket engine, wherein a 3D printing method is adopted to form the thrust chamber sandwich wall, and reference is specifically made to the following references: sen K, Mehta T, Sansure S, et al pharmaceutical applications of Powder-based Binder Jet 3D printing process-A Reviews [ J ]. Advanced Drug Delivery Reviews,2021: 113943.

Comparative example 3

The comparative example provides a manufacturing method of a rocket engine thrust chamber double-wall structure, which is different from the embodiment 1 only in the following parameters: the powder heating temperature was controlled at 400 ℃.

Comparative example 4

The comparative example provides a manufacturing method of a rocket engine thrust chamber double-wall structure, which is different from the embodiment 1 only in the following parameters: the spraying distance is 60 mm.

Test example 1

The service performance of the examples and the comparative examples is tested by referring to GB/T35777-2017

The results show that the service performance of the thrust chamber sandwich wall structure provided by the examples 1-6 is obviously superior to that of the comparative examples 1 and 2, and the low-temperature solid high-speed deposition technology rocket thrust chamber has the advantages of shorter manufacturing period and lower economic cost.

Test example 2

The combination properties such as strength, hardness and bonding strength of the examples and the comparative examples are tested, the test method is referred to GB/T35777-2017, and the test results are shown in Table 1.

Table 1 rocket thrust chamber performance test results

Group of	strength/MPa	hardness/HV 0.3	Bonding strength/MPa
				Example 1	186	456	103
Example 2	188	468	103
				Example 3	192	482	115
Example 4	213	503	135
				Example 5	201	494	123
Example 6	176	473	108
				Comparative example 1	165	416	95
Comparative example 2	178	325	98
				Comparative example 3	175	432	103
Comparative example 4	167	421	94

As can be seen from Table 1, the rocket thrust chamber prepared by the method of the embodiment of the invention has more excellent comprehensive performance, which is obviously better than that of the comparative example.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes will occur to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.