Metal ceramic space engine nozzle based on multi-material additive manufacturing

Abstract

The invention provides a space engine jet pipe based on multi-material metal ceramic additive manufacturing. The space engine jet pipe comprises a non-high-temperature area, a high-temperature area and a transition area. The non-high-temperature area is made of metal materials which comprise niobium alloy and titanium alloy. The high-temperature area is made of a ceramic material, and the component is SiC; the transition area realizes continuous gradient transition from non-high-temperature area metal to high-temperature area ceramic through multi-material additive manufacturing; the whole spray pipe is of a Laval spray pipe structure, and a non-high-temperature area, a high-temperature area and a transition area are integrally formed through additive manufacturing. The space engine can work in a higher performance interval, the space engine is suitable for combustion of an injector with higher specific impulse and a high-energy propellant, the thermal shock cycle life is prolonged, and meanwhile the weight of the whole spray pipe can be reduced.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of spacecraft propulsion systems, and particularly relates to a metal-ceramic space engine nozzle based on multi-material additive manufacturing. BACKGROUND

[0002] The space engine nozzle is an important component of heat power conversion, and when in operation, high-temperature combustion gas is converted into high-speed airflow and sprayed out, so as to make the engine generate thrust.

[0003] In order to improve the heat power conversion efficiency, the working temperature of the space engine nozzle is very high, and the nozzle structure of the current space engine is usually a metal substrate such as niobium alloy, and the inner and outer surfaces of the metal substrate are sprayed with an oxidation-resistant coating. Ceramics have higher high-temperature resistance and are good high-temperature structural material options, but the difference between the thermal expansion coefficients of ceramics and metal materials is large, the ceramics cannot be welded with the upstream metal material injector, and the overall ceramic nozzle has large brittleness and is prone to fatigue fracture under high-frequency pressure oscillation. The breakthrough of multi-material additive manufacturing technology provides a new way for metal-ceramic composite structures, which can break through the limitations of traditional processes and greatly improve the performance of the nozzle.

[0004] At present, the related prior art has: A segmented preparation method of a rhenium-niobium composite nozzle (patent document CN109807338) discloses a segmented preparation method of a rhenium-niobium composite nozzle, wherein the upper end and the lower end of the forming sleeve contain a niobium alloy component for forming a rhenium-niobium composite part. The sleeve filled with rhenium powder is first formed by low-temperature hot isostatic pressing, at this time, the rhenium component blank has a certain strength and a density of more than 99% after forming, and the rhenium-niobium transition zone of the upper part and the lower part is in the low-temperature zone of the nozzle operation, and can be directly machined and formed; and the rhenium matrix of the middle end is further densified and improved in metallurgical bonding strength after high-temperature sintering treatment, so that the mechanical properties meet the service requirements, and then machined and formed. Finally, the machined nozzle upper end, middle end and lower end are vacuum electron beam welded into a complete rhenium-niobium composite nozzle. However, this technical solution uses different alloy materials, and the upper limit of the thermal load is lower than that of ceramic-based materials, which cannot meet the demand for further improving the performance of the existing engine. Moreover, the complete nozzle is welded after machining, and there is a weld structure. The price of the metal material rhenium is very high, and it cannot be widely applied. SUMMARY

[0005] In view of the defects in the prior art, the purpose of the present application is to provide a metal-ceramic space engine nozzle based on multi-material additive manufacturing.

[0006] The metal-ceramic space engine nozzle based on multi-material additive manufacturing provided by the present application comprises a non-high-temperature zone, a high-temperature zone and a transition zone. The non-high-temperature zone adopts a metal material. The high-temperature zone adopts ceramic material; The transition zone realizes continuous gradient transition from non-high-temperature zone metal to high-temperature zone ceramic through multi-material additive manufacturing; the multi-material additive manufacturing-based metal-ceramic space engine nozzle is in a Laval nozzle configuration, and the non-high-temperature zone, the high-temperature zone and the transition zone are integrally formed through additive manufacturing; the transition zone structure is realized through gradient component co-sintering from ceramic phase to metal phase; the transition zone and the non-high-temperature zone are further connected through diffusion welding, and the transition zone and the high-temperature zone are further connected through sintering.

[0007] Preferably, the non-high-temperature zone comprises: a welding structure transition to a combustion chamber straight section, the welding structure being used for welding the nozzle and the engine head; The non-high-temperature zone is composed of niobium alloy and titanium alloy.

[0008] Preferably, the metal segment material of the transition zone is niobium alloy or titanium alloy, and the ceramic segment material is SiC, and the metal segment and the ceramic segment are integrally formed through multi-material additive manufacturing; the metal and the ceramic material are in gradient transition.

[0009] Preferably, the volume fraction of the metal phase of the transition zone decreases from 100% to 0%, and the volume fraction of the ceramic phase increases from 0% to 100%, the gradient layer thickness of the transition zone is greater than or equal to 1mm, and the interface is not peeled after 1000 times of thermal shock cycle at 1800℃.

[0010] Preferably, the high-temperature zone comprises: a nozzle converging section, a nozzle throat, a nozzle diverging section and a rib, The rib is connected between the nozzle converging section and the nozzle diverging section. The nozzle throat is arranged between the nozzle converging section and the nozzle diverging section, and the three are smoothly transitioned. The high-temperature zone is composed of SiC.

[0011] Preferably, the inner wall of the nozzle diverging section is provided as a Rao type maximum thrust profile.

[0012] Preferably, the rib is distributed in a radial manner around the nozzle, the number of the rib is 4 to 12, and the thickness of the rib is 2 to 3 times of the wall thickness.

[0013] Preferably, the welding structure, the combustion chamber straight section, the nozzle converging section, the nozzle throat, the nozzle diverging section and the rib are integrally formed through multi-material additive manufacturing.

[0014] Preferably, the combustion chamber straight section is a cylindrical thin-walled structure; and the combustion chamber straight section to the nozzle throat is a converging section with smooth transition.

[0015] Preferably, the welding structure, combustion chamber straight section, nozzle converging section, nozzle throat, nozzle diverging section and rib are integrally formed by multi-material additive manufacturing; laser powder bed melting technology is adopted, laser power is 300-1000 W, scanning speed is 100-800 mm / s; variable thickness design is adopted in additive manufacturing integral forming, and is processed, and is adaptively designed and integrally formed according to the thermal-mechanical load distribution of the use condition.

[0016] Compared with the prior art, the present application has the following beneficial effects: 1. The present application uses ceramics at higher working temperature structures and metals at general working temperatures by integrally forming metals and ceramics through additive manufacturing, the ceramic throat temperature resistance is increased to more than 2000 DEG C (niobium alloy nozzle ≤ 1400 DEG C), so that the space engine can work in a higher performance range, and adapt to higher specific impulse injectors and high-energy propellant combustion. 2. Compared with a single ceramic nozzle, the present application strengthens the mechanical strength of the nozzle structure through the metal structure part, and can be connected with the upstream metal material space engine injector by a very mature electron beam welding process. 3. The present application reduces the thermal stress of the connecting interface through the gradient transition of the metal part and the ceramic part of the nozzle, can avoid the interface cracking between the metal and the ceramic under high temperature working condition, and the thermal shock cycle life is ≥ 1000 times. 4. The density of the ceramic section of the present application (about 3.1 g / cm 3 ) is reduced by more than 65% than the density of niobium alloy (about 8.9 g / cm 3 ), so that the metal ceramic nozzle as a whole can be reduced by more than 50% compared with a single metal nozzle. 5. The present application sets the rib structure across the outside of the nozzle throat, connects the nozzle converging section and the nozzle diverging section, and can ensure that the structural strength of the integrally formed nozzle meets the use requirements. BRIEF DESCRIPTION OF DRAWINGS

[0017] Other features, objects and advantages of the present application will become more apparent from the following detailed description of non-limiting embodiments, made with reference to the accompanying drawings: Figure 1 The metal ceramic space engine nozzle schematic diagram provided for the examples of the present application.

[0018] The drawings show: DETAILED DESCRIPTION

[0019] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0020] According to an embodiment of the present invention, a metal-ceramic space engine nozzle based on multi-material additive manufacturing includes: a non-high-temperature zone 1, a high-temperature zone 2, and a transition zone 3. The non-high temperature zone 1 is made of metallic materials, with a composition of niobium alloy and titanium alloy; the high temperature zone 2 is made of ceramic materials, with a composition of SiC; the transition zone 3 achieves a continuous gradient transition from the metal in the non-high temperature zone 1 to the ceramic in the high temperature zone 2 through multi-material additive manufacturing; the metal-ceramic space engine nozzle based on multi-material additive manufacturing is an integral Laval nozzle configuration, and the three regions of non-high temperature zone 1, high temperature zone 2, and transition zone 3 are integrally formed through additive manufacturing; the structure of the transition zone 3 is achieved through a gradient composition co-sintering method from ceramic phase to metal phase; the transition zone 3 is further connected to the non-high temperature zone 1 through diffusion welding, and further connected to the high temperature zone 2 through sintering.

[0021] Furthermore, the non-high temperature zone 1 includes: a welded structure 11 transitioning to a straight section 12 of the combustion chamber, the welded structure 11 being used for welding the nozzle to the engine head; Furthermore, the high-temperature zone 2 includes: a nozzle converging section 21, a nozzle throat 22, a nozzle expanding section 23, and ribs 24. The ribs 24 span the outside of the nozzle throat 22 and connect the nozzle converging section 21 and the nozzle expanding section 23. The nozzle throat 22 is located between the nozzle converging section 21 and the nozzle expanding section 23, with a smooth transition between the three. The ribs 24 are used to strengthen the nozzle structure. The inner wall of the nozzle expanding section 23 is set as a Rao-type maximum thrust profile to maximize thrust conversion. More specifically, the ribs 24 are distributed radially around the nozzle, with a number of 4 to 12 and a thickness of 2 to 3 times the wall thickness, to suppress radial deformation under high-frequency oscillations.

[0022] Furthermore, the metal segment material of the transition zone 3 is niobium alloy or titanium alloy, and the ceramic segment material is SiC. The metal segment and the ceramic segment are integrated through multi-material additive manufacturing. The metal and ceramic materials are in a gradient transition, with the metal phase volume fraction decreasing from 100% to 0% and the ceramic phase volume fraction increasing from 0% to 100%. The gradient layer thickness of the transition zone 3 is ≥1mm. After 1000 thermal shock cycles at 1800℃, there is no interface peeling. The transition zone 3 can greatly alleviate the interface stress concentration between the two segments. Furthermore, the welded structure 11, the straight section 12 of the combustion chamber, the nozzle converging section 21, the nozzle throat 22, the nozzle expanding section 23, and the rib 24 are integrally formed through multi-material additive manufacturing; laser powder bed melting technology is used, with a laser power of 300 to 1000W and a scanning speed of 100 to 800 mm / s. Variable thickness design and processing are employed in the integral additive manufacturing process, and the design is adapted to the thermal-mechanical load distribution under the operating conditions and integrally formed.

[0023] More specifically, the straight section 12 of the combustion chamber is a cylindrical thin-walled structure; the straight section 12 of the combustion chamber to the nozzle throat 22 is a smoothly transitioning converging section 21.

[0024] In a more specific embodiment, such as Figure 1 As shown, the transition zone 3 achieves integrated molding of the metal segment and the ceramic segment through multi-material additive manufacturing. A gradient transition is set from the niobium alloy and titanium alloy metal segment to the SiC ceramic segment. The volume fraction of the metal phase decreases from 100% to 0%, and the volume fraction of the ceramic phase increases from 0% to 100%. The gradient layer thickness of the transition zone 3 is ≥1mm, and there is no interface peeling after 1000 thermal shock cycles at 1800℃. The welded structure 11 and the straight section 12 of the combustion chamber are made of niobium alloy and titanium alloy. The welded structure 11 is used for welding the nozzle to the engine head. The nozzle convergence section 21, the nozzle throat 22, the nozzle expansion section 23, and the rib 24 are made of SiC. The straight section 12 of the combustion chamber is a cylindrical thin-walled structure; the transition from the straight section 12 to the nozzle throat 22 is a smoothly transitioning converging section 21; the outer wall of the nozzle throat 22 has ribs 24, directly connecting the converging section 21 and the nozzle expanding section 23, used to strengthen the nozzle structure, distributed circumferentially in a radial pattern, numbering 6, with a thickness twice the wall thickness, used to suppress radial deformation under high-frequency oscillations. The inner wall of the nozzle expanding section 23 is designed with a Rao-type maximum thrust profile to maximize thrust conversion.

[0025] Furthermore, this invention achieves a continuous gradient transition from metal in the non-high temperature region to ceramic in the high temperature region through multi-material additive manufacturing of metal powder and ceramic powder, realizing integrated molding and a weld-free structure; and the ceramic powder is inexpensive, which is conducive to its widespread application.

[0026] In summary, this invention provides a space engine nozzle based on multi-material metal-ceramic additive manufacturing, comprising: a non-high-temperature zone 1, a high-temperature zone 2, and a transition zone 3; the non-high-temperature zone 1 is made of a metallic material, composed of niobium alloy and titanium alloy; the high-temperature zone 2 is made of a ceramic material, composed of SiC; the transition zone 3 achieves a continuous gradient transition from the metal of the non-high-temperature zone 1 to the ceramic of the high-temperature zone 2 through multi-material additive manufacturing; the nozzle as a whole adopts a Laval nozzle configuration, and the three regions of non-high-temperature zone 1, high-temperature zone 2, and transition zone 3 are integrally formed through additive manufacturing; this allows the space engine to operate in a higher performance range, adapt to higher specific impulse injectors and high-energy propellant combustion, extend thermal shock cycle life, and also reduce the overall weight of the nozzle.

[0027] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0028] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A metal-ceramic space engine nozzle based on multi-material additive manufacturing, characterized in that, include: Non-high temperature zone (1), high temperature zone (2), transition zone (3); The non-high temperature zone (1) is made of metallic material; The high-temperature zone (2) is made of ceramic material; The transition zone (3) achieves a continuous gradient transition from the non-high temperature zone (1) metal to the high temperature zone (2) ceramic through multi-material additive manufacturing; the metal-ceramic space engine nozzle based on multi-material additive manufacturing is an integral Laval nozzle configuration, and the three regions of non-high temperature zone (1), high temperature zone (2) and transition zone (3) are integrally formed through additive manufacturing; The transition zone (3) structure is achieved by co-sintering of the ceramic phase to the metal phase gradient components; the transition zone (3) is further connected to the non-high temperature zone (1) by diffusion welding, and further connected to the high temperature zone (2) by sintering.

2. The metal-ceramic space engine nozzle based on multi-material additive manufacturing according to claim 1, characterized in that, The non-high temperature zone (1) includes: a welded structure (11) transitioning to a straight section (12) of the combustion chamber, wherein the welded structure (11) is used for welding the nozzle to the engine head; The non-high temperature zone (1) is composed of niobium alloy and titanium alloy.

3. The metal-ceramic space engine nozzle based on multi-material additive manufacturing according to claim 1, characterized in that, The metal segment material of the transition zone (3) is niobium alloy or titanium alloy, and the ceramic segment material is SiC. The metal segment and the ceramic segment are integrated through multi-material additive manufacturing; the metal and ceramic materials are in a gradient transition.

4. The metal-ceramic space engine nozzle based on multi-material additive manufacturing according to claim 3, characterized in that, The volume fraction of the metal phase in the transition zone (3) decreases from 100% to 0%, and the volume fraction of the ceramic phase increases from 0% to 100%. The gradient layer thickness of the transition zone (3) is ≥1mm, and there is no peeling at the interface after 1000 thermal shock cycles at 1800℃.

5. The metal-ceramic space engine nozzle based on multi-material additive manufacturing according to claim 2, characterized in that, The high-temperature zone (2) includes: the nozzle convergent section (21), the nozzle throat (22), the nozzle diverging section (23), and the rib (24). The rib (24) spans the outside of the nozzle throat (22) and connects the nozzle converging section (21) and the nozzle expanding section (23). The nozzle throat (22) is located between the nozzle converging section (21) and the nozzle expanding section (23), and the three sections transition smoothly. The high-temperature zone (2) is composed of SiC.

6. The metal-ceramic space engine nozzle based on multi-material additive manufacturing according to claim 5, characterized in that, The inner wall of the nozzle expansion section (23) is configured as a Rao-type maximum thrust profile.

7. The metal-ceramic space engine nozzle based on multi-material additive manufacturing according to claim 5, characterized in that, The ribs (24) are distributed radially around the nozzle, numbering 4 to 12, and are 2 to 3 times the wall thickness.

8. The metal-ceramic space engine nozzle based on multi-material additive manufacturing according to claim 6, characterized in that, The welded structure (11), the straight section of the combustion chamber (12), the nozzle converging section (21), the nozzle throat (22), the nozzle expanding section (23), and the rib (24) are integrally formed by multi-material additive manufacturing.

9. The metal-ceramic space engine nozzle based on multi-material additive manufacturing according to claim 8, characterized in that, The straight section (12) of the combustion chamber is a cylindrical thin-walled structure; the straight section (12) of the combustion chamber to the nozzle throat (22) is a smoothly transitioning converging section (21).

10. The metal-ceramic space engine nozzle based on multi-material additive manufacturing according to claim 8, characterized in that, The welded structure (11), the straight section of the combustion chamber (12), the nozzle convergence section (21), the nozzle throat (22), the nozzle expansion section (23), and the rib (24) are integrally formed by multi-material additive manufacturing; laser powder bed melting technology is adopted, with laser power of 300 to 1000W and scanning speed of 100 to 800mm / s; in the integral forming of additive manufacturing, a variable thickness design is adopted and processed, and the thermal-mechanical load distribution is adapted to the operating conditions and integrally formed.

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