Ultra-high temperature and high-speed jet resistant materials and construction processes for vehicle-mounted flow deflectors at space launch sites

Abstract

The present invention belongs to the technical field of refractories, and particularly relates to a material resistant to ultra-high temperature and high-speed jets for vehicle-mounted deflectors at space launch sites and a construction process thereof. In the present invention, components such as mullite and corundum are selected as matrix materials, while nano-scale superfine powders such as nano-silicon carbide and nano-aluminum oxide are added. In addition, a small amount of graphite is added for adjustment to obtain a material resistant to ultra-high temperature and high-speed jets, effectively improving the normal temperature compressive strength of the material, reducing the ablation rate, and simultaneously obtaining good refractoriness.

Description

Technical Field

[0001] The present invention belongs to the technical field of refractory materials, and particularly relates to a super high temperature and high speed jet resistant material and construction process for vehicle-mounted deflectors at space launch sites. Background Art

[0002] The vehicle-mounted deflector at a space launch site is a key device in the rocket launch system. It is mainly used to guide and disperse the high-temperature and high-speed gas flow ejected from the rocket engine, avoid its direct impact on the launch pad and surrounding facilities, and at the same time reduce the impact of thermal radiation, acoustic vibration on the launch site, ensuring the safety of personnel and equipment. The vehicle-mounted deflector at a space launch site is the "invisible guardian" of the rocket launch system, and its design integrates cutting-edge technologies in materials science, fluid mechanics and thermal management. In order to withstand extreme conditions, such as super high temperature (up to thousands of degrees Celsius), high-speed jet impact and possible chemical erosion, the materials used must have extremely high heat resistance, mechanical strength and chemical stability; high-speed jet materials refer to materials that can withstand extreme environments such as high-speed fluid impact, high temperature, high pressure and corrosion, and the materials need to have the following core characteristics: ultra-high melting point, thermal shock resistance, ablation resistance, high strength and oxidation / corrosion resistance.

[0003] Chinese Patent (Publication No. CN104311054A) discloses a composite refractory castable, which is made of the following components in parts by weight: corundum 10-15 parts, mullite 10-15 parts, silicon carbide 10-15 parts, silica fume 5-10 parts, magnesite 15-20 parts, graphite 10-15 parts, alumina micropowder 10-15 parts, phenolic resin 2-10 parts, carbon nanotubes 3-10 parts. When applying refractory materials to vehicle-mounted deflectors at space launch sites in the prior art, there are problems such as insufficient normal temperature compressive strength of the materials, too large ablation rate, and low refractoriness, seriously affecting their actual use.

[0004] Therefore, there is an urgent need for a super high temperature and high speed jet resistant material for vehicle-mounted deflectors at space launch sites. By screening the components of the material and selecting appropriate particle sizes and ratios, the normal temperature compressive strength of the material is improved, the ablation rate is reduced, and good refractoriness is obtained at the same time. Summary of the Invention

[0005] The purpose of the present invention is to provide a super high temperature and high speed jet resistant material and construction process for vehicle-mounted deflectors at space launch sites. Mullite, corundum and other components are selected as matrix materials, and nano-scale superfine powders such as nano silicon carbide and nano alumina are added at the same time. In addition, a small amount of graphite is added for adjustment to obtain a super high temperature and high speed jet resistant material, effectively improving the normal temperature compressive strength of the material, reducing the ablation rate, and obtaining good refractoriness at the same time.

[0006] In order to achieve the above purpose, the present invention provides the following technical solutions:

[0007] In the first aspect of the present invention, a material resistant to ultra-high temperature and high-speed jets for vehicle-mounted deflectors at a space launch site is provided. Calculated by weight parts, it includes the following components: 36 - 40 parts of mullite, 26 - 30 parts of nano-scale superfine powder, 23 - 27 parts of corundum powder, 1 - 2 parts of alloy fiber, and 2 - 3 parts of graphite.

[0008] In the present invention, by designing the components of the material resistant to ultra-high temperature and high-speed jets, and further through the combined use of mullite, nano-scale superfine powder, corundum powder, alloy fiber, and graphite, the normal-temperature compressive strength of the material is effectively improved, the ablation rate is reduced, and good refractoriness is obtained at the same time.

[0009] As a preferred solution, the weight parts of the mullite in the present invention can be 36 parts, 37 parts, 36 parts, 38 parts, 39 parts, or 40 parts, etc.; preferably, the weight parts of the mullite are 36 parts, 38 parts, or 40 parts. As a preferred solution, the mesh number of the mullite is 300 - 400 mesh; preferably, the mesh number of the mullite is 310 - 340 mesh; further preferably, the mesh number of the mullite is 320 mesh.

[0010] There are a large number of covalent bonds and ionic bonds inside the mullite, which can withstand a large external pressure without being easily damaged, endowing the material with excellent normal-temperature compressive strength; the low thermal expansion coefficient and high thermal stability of the mullite make it not easily undergo physical and chemical changes in a high-temperature environment, so that the material has a relatively low maximum ablation rate; the melting point of the mullite is very high, and it can form a protective glaze layer at high temperatures, further preventing the conduction of heat, thereby protecting the material from high-temperature damage, and thus having extremely high refractoriness.

[0011] As a preferred solution, the weight parts of the nano-scale superfine powder in the present invention can be 26 parts, 27 parts, 28 parts, 29 parts, or 30 parts, etc.; preferably, the weight parts of the nano-scale superfine powder are 26 parts, 28 parts, or 30 parts.

[0012] As a preferred solution, the nano-scale superfine powder is nano-silicon carbide and nano-aluminum oxide.

[0013] As a preferred solution, the mass ratio of nano-silicon carbide to nano-aluminum oxide in the nano-scale superfine powder is (1 - 2):1, for example, it can be 1:1, 1.1:1, 1.2:1, 1.3:1, 1.4:1, 1.5:1, 1.6:1, 1.7:1, 1.8:1, 1.9:1, or 2:1, etc.

[0014] As a preferred solution, the particle size of the nano silicon carbide is 40 - 50 nm; preferably, the particle size of the nano silicon carbide is 40 - 45 nm; more preferably, the particle size of the nano silicon carbide is 40 nm. As a preferred solution, the particle size of the nano alumina is 10 - 20 nm; preferably, the particle size of the nano alumina is 10 - 15 nm; more preferably, the particle size of the nano alumina is 10 nm.

[0015] As a preferred solution, the weight parts of the corundum powder in the present invention can be 23 parts, 24 parts, 25 parts, 26 parts, 27 parts, etc.; preferably, the weight parts of the corundum powder are 23 parts, 25 parts or 27 parts.

[0016] As a preferred solution, the weight parts of the alloy fiber in the present invention can be 1 part, 1.2 parts, 1.4 parts, 1.6 parts, 1.8 parts, 2 parts, etc.

[0017] As a preferred solution, the weight parts of the graphite in the present invention can be 2 parts, 2.2 parts, 2.4 parts, 2.6 parts, 2.8 parts, 3 parts, etc.; preferably, the weight parts of the graphite are 2 parts or 3 parts.

[0018] As a preferred solution, the particle size of the graphite is 500 - 800 nm; preferably, the particle size of the graphite is 500 - 600 nm; more preferably, the particle size of the graphite is 500 nm.

[0019] At high temperatures, graphite can form a dense carbonized layer to resist oxidation and ablation. Adding graphite can significantly reduce the maximum ablation rate of the material, especially in high-temperature or high-speed gas flow environments; in addition, graphite has excellent refractory properties, and its addition can increase the refractoriness of the material and keep the material stable in high-temperature environments.

[0020] The second aspect of the present invention provides a construction process for the ultra-high temperature and high-speed jet-resistant material for vehicle-mounted flow deflectors at space launch sites as described in the first aspect, including the following steps:

[0021] (1) Marking, drawing the layout dimensions of the anchor bolts; laying out and drawing according to the layout dimensions designed in the construction drawing, densifying the corners and special parts, and lengthening and shortening according to the thickness of the castable. For parts exceeding the empirical layout spacing of the pins (grab nails), it is especially necessary to add metal claw nails.

[0022] (2) Welding, inspecting the welding quality of the anchor bolts; after welding, the welding slag should be polished and cleaned according to the welding specifications, and the welding strength of each anchor bolt should be checked one by one by methods such as hammering or manual bending.

[0023] (3) Prepare the material resistant to ultra-high temperature and high-speed jet for the vehicle-mounted deflector at the space launch site, and then pour it.

[0024] (4) Vibrate. Use an internal vibrator to vibrate. When vibrating, slowly insert it into the material layer for continuous vibration and then slowly pull it out; to prevent leaving holes and vibration omission, and at the same time prevent the coarse aggregate from floating up. During the vibration process, the vibrator shall not collide with the formwork and hook nails too much; before pouring the castable, clean the inside of the formwork. When pouring the material at the joint part, first clean the joint surface of the original castable, wet the pouring contact surface and then pour the lower-section castable. Try to avoid using vibrated castable at parts with too small thickness.

[0025] (5) Remove the formwork. Remove the formwork 12 - 24 hours after the castable is poured well, and keep the ambient temperature at 15 - 20 °C.

[0026] (6) Cure. After removing the formwork, cure by electric baking for 5 - 6 days.

[0027] As a preferred solution, the preparation method in step (3) includes: mix each component according to weight parts, then add water with a pH of 6.5 - 8.5 and stir for 6 - 8 minutes, and the water addition amount is 5 - 7%; the pH of the water can be 6.5, 7.0, 7.5, 8.0 or 8.5; the stirring time can be 6 minutes, 6.5 minutes, 7 minutes, 7.5 minutes or 8 minutes; the water addition amount can be 5%, 5.5%, 6%, 6.5% or 7%.

[0028] As a preferred solution, the vibration time in step (4) is 5 - 10 minutes; the vibration time can be 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes, 10 minutes.

[0029] Compared with the prior art, the advantages and beneficial effects of the present invention are:

[0030] 1. The present invention selects components such as mullite and corundum as the matrix material, and at the same time adds nano-scale superfine powders such as nano silicon carbide and nano alumina, and additionally adds a small amount of graphite for adjustment to obtain the material resistant to ultra-high temperature and high-speed jet. By strictly controlling the particle size and mass ratio of the components, the normal temperature compressive strength of the material is effectively improved, the ablation rate is reduced, and at the same time good refractoriness is obtained.

[0031] 2. The nano-scale silicon carbide particles in the present invention can have a strong interfacial bonding force with the material matrix, which not only increases the ability of the composite material to resist external forces, but also helps to effectively transfer the applied stress to the silicon carbide particles, thereby improving the normal temperature compressive strength of the material.

[0032] 3. By adding nano-aluminum oxide to the high-speed jet material, a denser and more uniform microstructure can be formed, reducing the pores and cracks inside the material. Through structural optimization, the intrusion of oxygen and other corrosive media can be effectively prevented, thereby reducing the ablation rate of the material.

[0033] 4. By using the compound of nano-silicon carbide and nano-aluminum oxide, the nano-silicon carbide fills the pores of the material matrix, and the nano-aluminum oxide closes the microcracks in one step to form a double-dense structure. At the same time, under high-temperature conditions, the nano-silicon carbide particles hinder the dislocation movement, and the nano-aluminum oxide inhibits the grain boundary slip, delaying the high-temperature creep. The comprehensive effect improves the refractoriness. Specific Embodiments

[0034] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0035] The sources of some components in the examples and comparative examples are as follows:

[0036] Mullite I, 320 mesh, purchased from Xinmi Zhengyang Foundry Materials Factory;

[0037] Mullite II, 180 mesh, purchased from Xinmi Zhengyang Foundry Materials Factory;

[0038] Nano-silicon carbide I, product number S104653, particle size of 40 nm, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.;

[0039] Nano-silicon carbide II, product number S104651, particle size of 600 nm, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.;

[0040] Nano-aluminum oxide I, product number A140296, particle size of 10 nm, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.;

[0041] Nano-aluminum oxide II, product number A498369, particle size of 300 nm, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.;

[0042] Corundum powder, purchased from Henan Yumo New Materials Co., Ltd.;

[0043] Alloy fiber, purchased from Xinyu Jintong Technology Co., Ltd.;

[0044] Graphite I, model XT-C2-03, particle size of 500 nm, purchased from Shanghai Xiangtian Nano Materials Co., Ltd.;

[0045] Graphite II, model XT-C2-07, particle size 5μm, purchased from Shanghai Xiangtian Nanomaterials Co., Ltd.;

[0046] Graphite III, model XT-C2-01, particle size 100nm, purchased from Shanghai Xiangtian Nanomaterials Co., Ltd.;

[0047] Example 1

[0048] This example provides a material resistant to ultra-high temperature and high-speed jets for vehicle-mounted deflectors at space launch sites. By weight, it includes the following components: 40 parts of mullite I (320 mesh), 30 parts of nano-scale superfine powder (20 parts of nano-silicon carbide I and 10 parts of nano-aluminum oxide I), 27 parts of corundum powder, 2 parts of alloy fiber, and 3 parts of graphite I (particle size 500nm).

[0049] Example 2

[0050] This example provides a material resistant to ultra-high temperature and high-speed jets for vehicle-mounted deflectors at space launch sites. By weight, it includes the following components: 36 parts of mullite I (320 mesh), 26 parts of nano-scale superfine powder (13 parts of nano-silicon carbide I and 13 parts of nano-aluminum oxide I), 23 parts of corundum powder, 1 part of alloy fiber, and 2 parts of graphite I (particle size 500nm).

[0051] Example 3

[0052] This example provides a material resistant to ultra-high temperature and high-speed jets for vehicle-mounted deflectors at space launch sites. By weight, it includes the following components: 38 parts of mullite I (320 mesh), 28 parts of nano-scale superfine powder (16 parts of nano-silicon carbide I and 12 parts of nano-aluminum oxide I), 25 parts of corundum powder, 1.4 parts of alloy fiber, and 3 parts of graphite I (particle size 500nm).

[0053] Comparative Example 1

[0054] The difference between this comparative example and Example 1 is that mullite II (180 mesh) is used to replace mullite I (320 mesh).

[0055] Comparative Example 2

[0056] The difference between this comparative example and Example 1 is that the number of parts of nano-silicon carbide I in the nano-scale superfine powder is changed to 25 parts, and the number of parts of nano-aluminum oxide I is changed to 5 parts.

[0057] Comparative Example 3

[0058] The difference between this comparative example and Example 1 is that the number of parts of nano-silicon carbide I in the nano-scale superfine powder is changed to 10 parts, and the number of parts of nano-aluminum oxide I is changed to 20 parts.

[0059] Comparative Example 4

[0060] The difference between this comparative example and Example 1 is that nano silicon carbide II (particle size 600 nm) is used to replace nano silicon carbide I (particle size 40 nm).

[0061] Comparative Example 5

[0062] The difference between this comparative example and Example 1 is that nano alumina II (particle size 300 nm) is used to replace nano alumina I (particle size 10 nm).

[0063] Comparative Example 6

[0064] The difference between this comparative example and Example 1 is that graphite II (particle size 5 μm) is used to replace graphite I (particle size 500 nm).

[0065] Comparative Example 7

[0066] The difference between this comparative example and Example 1 is that graphite III (particle size 100 nm) is used to replace graphite I (particle size 500 nm).

[0067] Performance Test

[0068] The above examples and comparative examples are subjected to the following tests:

[0069] (1) Normal temperature compressive strength test: The test is carried out with reference to the requirements of "GB / T 4513.6-2017 Unshaped refractory - Part 6: Determination of physical properties".

[0070] (2) Maximum ablation rate test: The test is carried out with reference to the requirements of "GJB 1597A-2018 Specification for low ablation rate refractory concrete for rocket launch pad flow guiding trough".

[0071] (3) Refractoriness test: The test is carried out with reference to the requirements of "GB / T 7322-2017 Refractory materials - Test method for refractoriness".

[0072] Table 1 Performance test results [[ID=३८]]

[0073]

[0074] From the above performance test results, it can be seen that the comprehensive performance of Examples 1-3 is the best, the normal temperature compressive strength (500 °C / 3 h) is 266-271 MPa, the maximum ablation rate is 0.834-0.839 mm / s, and the refractoriness > 1800 °C; this is mainly because by strictly controlling the particle size and mass ratio of the components, the normal temperature compressive strength of the material is effectively improved, the ablation rate is reduced, and good refractoriness is obtained at the same time.

[0075] Compared with Example 1, in Comparative Example 1, mullite II (180 mesh) was used to replace mullite I (320 mesh). Due to the inappropriate mesh number of mullite II, the cold crushing strength of the material decreased, the maximum ablation rate increased, and the refractoriness became worse. Compared with Example 1, in Comparative Example 2, the amount of nano-silicon carbide I in the nano-scale superfine powder was changed to 25 parts, and the amount of nano-aluminum oxide I was changed to 5 parts. Due to the excessive amount of nano-silicon carbide I and poor compounding effect, the cold crushing strength of the material decreased, the maximum ablation rate increased, and the refractoriness became worse. Compared with Example 1, in Comparative Example 3, the amount of nano-silicon carbide I in the nano-scale superfine powder was changed to 10 parts, and the amount of nano-aluminum oxide I was changed to 20 parts. Due to the insufficient amount of nano-silicon carbide I and poor compounding effect, the cold crushing strength of the material decreased, the maximum ablation rate increased, and the refractoriness became worse. Compared with Example 1, in Comparative Example 4, nano-silicon carbide II (particle size of 600 nm) was used to replace nano-silicon carbide I (particle size of 40 nm). Due to the too large particle size of nano-silicon carbide II, the cold crushing strength of the material decreased, the maximum ablation rate increased, and the refractoriness became worse. Compared with Example 1, in Comparative Example 5, nano-aluminum oxide II (particle size of 300 nm) was used to replace nano-aluminum oxide I (particle size of 10 nm). Due to the too large particle size of nano-aluminum oxide II, the cold crushing strength of the material decreased, the maximum ablation rate increased, and the refractoriness became worse. Compared with Example 1, in Comparative Example 6, graphite II (particle size of 5 μm) was used to replace graphite I (particle size of 500 nm). Due to the too large particle size of graphite II, the cold crushing strength of the material decreased, the maximum ablation rate increased, and the refractoriness became worse. Compared with Example 1, in Comparative Example 7, graphite III (particle size of 100 nm) was used to replace graphite I (particle size of 500 nm). Due to the too small particle size of graphite III, the cold crushing strength of the material decreased, the maximum ablation rate increased, and the refractoriness became worse.

Claims

1. A material resistant to ultra-high temperature and high-speed jet for vehicle-mounted flow deflectors at a space launch site, characterized in that by weight, it comprises the following components: 36-40 parts of mullite, 26-30 parts of nano-scale superfine powder, 23-27 parts of corundum powder, 1-2 parts of alloy fiber and 2-3 parts of graphite; the mesh number of the mullite is 300-400 mesh; the nano-scale superfine powder is nano-silicon carbide and nano-aluminum oxide, and the mass ratio is (1-2):1; the particle size of the nano-silicon carbide is 40-50 nm; the particle size of the nano-aluminum oxide is 10-20 nm; the particle size of the graphite is 500-800 nm; the refractoriness of the material > 1800 °C, the compressive strength under the conditions of 500 °C and 3 h is 271 MPa; the maximum ablation rate is 0.839 mm / s.

2. A construction process of the material resistant to ultra-high temperature and high-speed jet for vehicle-mounted flow deflectors at a space launch site according to claim 1, characterized in that it comprises the following steps: (1) Marking lines, drawing lines for the layout dimensions of the anchor bolts; (2) Welding, inspecting the welding quality of the anchor bolts; (3) Preparing the material resistant to ultra-high temperature and high-speed jet for the vehicle-mounted flow deflectors at the space launch site, and then pouring; (4) Vibrating, using an inserted vibrating rod for vibrating. When vibrating, slowly insert it into the material layer for continuous vibration and slowly pull it out; (5) Demolding, demolding 12-24 h after the casting material is poured well, and keeping the ambient temperature at 15-20 °C; (6) Curing, curing by electric baking for 5-6 days after demolding.

3. According to the construction process of claim 2, characterized in that the preparation method in step (3) includes: mixing each component according to the weight parts, then adding water with a pH of 6.5-8.5 and stirring for 6-8 min, and the water addition amount is 5-7%.

4. According to the construction process of claim 2, characterized in that the vibrating time in step (4) is 5-10 min.

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