Ultrahigh-temperature-resistant high-speed jet material for vehicle-mounted fluid director of spaceflight launching site and construction process

Abstract

The invention belongs to the technical field of refractory materials, and particularly relates to an ultrahigh-temperature-resistant high-speed jet material for a vehicle-mounted fluid director in a spaceflight launching site and a construction process. According to the invention, mullite, corundum and other components are selected as base materials, nano-scale super micro powder such as nano silicon carbide and nano aluminum oxide is added at the same time, and a small amount of graphite is added for adjustment, so that the ultrahigh-temperature-resistant high-speed jet material is obtained, the normal-temperature compressive strength of the material is effectively improved, the ablation rate is reduced, and meanwhile, good refractoriness is obtained.

Description

Technical Field

[0001] The present invention belongs to the technical field of refractory materials, and in particular relates to an ultra-high temperature resistant high-speed jet material and a construction process for a vehicle-mounted deflector at a space launch site. Background Art

[0002] The vehicle-mounted deflector at the 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 by the rocket engine to prevent it from directly impacting the launch pad and surrounding facilities, while reducing the impact of thermal radiation and acoustic vibration shock on the launch site to ensure the safety of personnel and equipment. The vehicle-mounted deflector at the space launch site is the "invisible guardian" of the rocket launch system. Its design integrates cutting-edge technologies in materials science, fluid mechanics and thermal management. In order to withstand extreme conditions such as ultra-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. The materials must have the following core characteristics: ultra-high melting point, thermal shock resistance, ablation resistance, high strength and oxidation / corrosion resistance.

[0003] A Chinese patent (publication number CN104311054A) discloses a composite refractory castable, which is made of the following weight components: 10-15 parts of corundum, 10-15 parts of mullite, 10-15 parts of silicon carbide, 5-10 parts of silica fume, 15-20 parts of magnesia, 10-15 parts of graphite, 10-15 parts of alumina powder, 2-10 parts of phenolic resin, and 3-10 parts of carbon nanotubes. In the prior art, when refractory materials are applied to the vehicle-mounted deflector of the space launch site, there are problems such as insufficient room temperature compressive strength of the material, excessive ablation rate, and low refractoriness, which seriously affect its actual use.

[0004] Therefore, there is an urgent need for an ultra-high temperature and high-speed jet material resistant to the vehicle-mounted deflector of a space launch site. By screening the components of the material and selecting the appropriate particle size and proportion, the room temperature compressive strength of the material can be improved, the ablation rate can be reduced, and good refractoriness can be obtained. Summary of the invention

[0005] The purpose of the present invention is to provide an ultra-high temperature high-speed jet material and a construction process for a space launch site vehicle-mounted deflector. Mullite, corundum and other components are selected as matrix materials, and nano-silicon carbide, nano-alumina and other nano-scale super powders are added. A small amount of graphite is also added for adjustment to obtain an ultra-high temperature high-speed jet material, which effectively improves the room temperature compressive strength of the material, reduces the ablation rate, and obtains good refractoriness.

[0006] In order to achieve the above object, the present invention provides the following technical solutions: The first aspect of the present invention provides an ultra-high temperature and high-speed jet material for a space launch site vehicle-mounted deflector, which comprises the following components, in parts by weight: 36 to 40 parts of mullite, 26 to 30 parts of nano-grade superfine powder, 23 to 27 parts of corundum powder, 1 to 2 parts of alloy fiber and 2 to 3 parts of graphite.

[0007] In the present invention, by designing the components of the ultra-high temperature high-speed jet material, and further using mullite, nano-level superfine powder, corundum powder, alloy fiber and graphite in combination, the room temperature compressive strength of the material is effectively improved, the ablation rate is reduced, and good refractoriness is obtained.

[0008] As a preferred solution, the weight proportion 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 proportion of the mullite is 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.

[0009] Mullite contains a large number of covalent bonds and ionic bonds, which can withstand greater external pressure without being easily damaged, giving the material excellent room-temperature compressive strength; mullite's low thermal expansion coefficient and high thermal stability make it less likely to undergo physical and chemical changes in high-temperature environments, so the material has a lower maximum ablation rate; mullite has a high melting point and can form a protective glaze layer at high temperatures, further preventing heat conduction and protecting the material from high temperature damage, thus having extremely high refractoriness.

[0010] As a preferred solution, the weight proportion 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 proportion of the nano-scale superfine powder is 26 parts, 28 parts or 30 parts.

[0011] As a preferred solution, the nano-scale superfine powder is nano-silicon carbide and nano-aluminum oxide.

[0012] As a preferred embodiment, the mass ratio of nano-silicon carbide and nano-aluminum oxide in the nano-scale super 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.

[0013] As a preferred solution, the particle size of the nano silicon carbide is 40-50nm; preferably, the particle size of the nano silicon carbide is 40-45nm; more preferably, the particle size of the nano silicon carbide is 40nm. As a preferred solution, the particle size of the nano aluminum oxide is 10-20nm; preferably, the particle size of the nano aluminum oxide is 10-15nm; more preferably, the particle size of the nano aluminum oxide is 10nm.

[0014] As a preferred solution, the weight proportion of the corundum powder in the present invention can be 23 parts, 24 parts, 25 parts, 26 parts or 27 parts, etc.; preferably, the weight proportion of the corundum powder is 23 parts, 25 parts or 27 parts.

[0015] As a preferred solution, the weight proportion of the alloy fiber in the present invention can be 1 part, 1.2 parts, 1.4 parts, 1.6 parts, 1.8 parts or 2 parts.

[0016] As a preferred solution, the weight proportion of the graphite in the present invention can be 2 parts, 2.2 parts, 2.4 parts, 2.6 parts, 2.8 parts or 3 parts, etc.; preferably, the weight proportion of the graphite is 2 parts or 3 parts.

[0017] 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; further preferably, the particle size of the graphite is 500 nm.

[0018] At high temperatures, graphite can form a dense carbonized layer that resists oxidation and ablation. Adding graphite can significantly reduce the maximum ablation rate of the material, especially in high temperature or high-speed airflow environments. In addition, graphite has excellent fire resistance, and its addition can improve the refractoriness of the material and keep the material stable in high temperature environments.

[0019] The second aspect of the present invention provides a construction process of the ultra-high temperature resistant high-speed jet material for the vehicle-mounted deflector of the space launch site as described in the first aspect, comprising the following steps: (1) Marking: Marking the layout dimensions of anchors; marking the layout dimensions according to the construction drawing design, encrypting the corners and special parts, and lengthening or shortening them according to the thickness of the castable. For parts that exceed the empirical layout spacing of pins (grasping nails), it is especially necessary to add metal claw nails; (2) Welding, anchor welding quality inspection; after welding, the welding slag should be polished and cleaned according to the welding specifications, and the welding strength of each anchor should be checked one by one by hammering or manual bending; (3) preparing the ultra-high temperature resistant high-speed jet material for the vehicle-mounted deflector of the space launch site, and then pouring it; (4) Vibration: Use an inserted vibrating rod for vibration. Slowly insert the vibrating rod into the material layer and vibrate continuously, then slowly pull it out to prevent holes and vibration leakage, and to prevent coarse aggregate from floating up. During the vibration process, the vibrating rod should not collide with the formwork or hooks too much. Before pouring the castable, the formwork should be cleaned. When pouring the material at the joint, first clean the joint surface of the original castable, wet the contact surface before pouring the next section of the castable. Try to avoid using vibrating castables in areas with too small thickness. (5) Demolding: demold the mold 12 to 24 hours after the castable is poured, and maintain the ambient temperature at 15 to 20°C; (6) Curing: After demolding, electric baking is performed for 5 to 6 days for curing.

[0020] As a preferred solution, the preparation method of step (3) comprises: mixing the components in parts by weight, and then adding water with a pH of 6.5 to 8.5 and stirring for 6 to 8 minutes, wherein the amount of water added is 5 to 7%; the pH of the water may be 6.5, 7.0, 7.5, 8.0 or 8.5; the stirring time may be 6 minutes, 6.5 minutes, 7 minutes, 7.5 minutes or 8 minutes; and the amount of water added may be 5%, 5.5%, 6%, 6.5% or 7%.

[0021] As a preferred solution, the vibration time in step (4) is 5 to 10 minutes; the vibration time can be 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes, or 10 minutes.

[0022] Compared with the prior art, the advantages and beneficial effects of the present invention are: 1. The present invention selects mullite, corundum and other components as matrix materials, and adds nano-scale super powders such as nano silicon carbide and nano alumina, and further adds a small amount of graphite for adjustment to obtain ultra-high temperature high-speed jet materials. By strictly controlling the particle size and mass ratio of the components, the room temperature compressive strength of the material is effectively improved, the ablation rate is reduced, and good refractoriness is obtained.

[0023] 2. The nano-scale silicon carbide particles of the present invention can have a strong interface 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 external stress to the silicon carbide particles, thereby improving the room temperature compressive strength of the material.

[0024] 3. The present invention can form a more compact and uniform microstructure in the high-speed jet material by adding nano-alumina, reduce the pores and cracks inside the material, and effectively prevent the intrusion of oxygen and other corrosive media through structural optimization, thereby reducing the ablation rate of the material.

[0025] 4. The present invention uses a compound of nano-silicon carbide and nano-alumina, wherein nano-silicon carbide fills the pores of the material matrix and nano-alumina seals the microcracks in one step to form a double dense structure; at the same time, under high temperature conditions, nano-silicon carbide particles hinder dislocation movement, and nano-alumina inhibits grain boundary sliding and delays high-temperature creep, and the combined effect improves refractoriness. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] The sources of some components in the embodiments and comparative examples are as follows: Mullite I, 320 mesh, purchased from Xinmi Zhengyang Foundry Material Factory; Mullite II, 180 mesh, purchased from Xinmi Zhengyang Foundry Material Factory; Nano-silicon carbide I, product number S104653, particle size 40 nm, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.; Nano-SiC II, product number S104651, particle size 600 nm, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.; Nano-alumina I, product number A140296, particle size 10 nm, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.; Nano-alumina II, product number A498369, particle size 300 nm, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.; Corundum powder was purchased from Henan Yumo New Materials Co., Ltd.; Alloy fiber was purchased from Xinyu Jintong Technology Co., Ltd. Graphite I, model XT-C2-03, particle size 500 nm, purchased from Shanghai Xiangtian Nanomaterials Co., Ltd.; Graphite II, model XT-C2-07, particle size 5 μm, purchased from Shanghai Xiangtian Nanomaterials Co., Ltd.; Graphite III, model XT-C2-01, particle size 100 nm, purchased from Shanghai Xiangtian Nanomaterials Co., Ltd.; Example 1 The present embodiment provides an ultra-high temperature resistant high-speed jet material for a space launch site vehicle-mounted deflector, which includes the following components, in parts by weight: 40 parts of mullite I (320 mesh), 30 parts of nano-grade super fine powder (20 parts of nano-silicon carbide I and 10 parts of nano-alumina I), 27 parts of corundum powder, 2 parts of alloy fiber and 3 parts of graphite I (particle size is 500nm).

[0028] Example 2 The present embodiment provides an ultra-high temperature resistant high-speed jet material for a space launch site vehicle-mounted deflector, which includes the following components, in parts by weight: 36 parts of mullite I (320 mesh), 26 parts of nano-grade super fine powder (13 parts of nano-silicon carbide I and 13 parts of nano-alumina I), 23 parts of corundum powder, 1 part of alloy fiber and 2 parts of graphite I (particle size is 500nm).

[0029] Example 3 The present embodiment provides an ultra-high temperature resistant high-speed jet material for a space launch site vehicle-mounted deflector, which includes the following components, in parts by weight: 38 parts of mullite I (320 mesh), 28 parts of nano-grade super fine powder (16 parts of nano-silicon carbide I and 12 parts of nano-alumina I), 25 parts of corundum powder, 1.4 parts of alloy fiber and 3 parts of graphite I (particle size is 500nm).

[0030] Comparative Example 1 The difference between this comparative example and Example 1 is that mullite II (180 mesh) is used to replace mullite I (320 mesh).

[0031] Comparative Example 2 The difference between this comparative example and Example 1 is that the proportion of nano silicon carbide I in the nano-grade superfine powder is changed to 25 parts, and the proportion of nano aluminum oxide I is changed to 5 parts.

[0032] Comparative Example 3 The difference between this comparative example and Example 1 is that the proportion of nano silicon carbide I in the nano-grade superfine powder is changed to 10 parts, and the proportion of nano aluminum oxide I is changed to 20 parts.

[0033] Comparative Example 4 The difference between this comparative example and Example 1 is that nano-silicon carbide II (with a particle size of 600 nm) is used to replace nano-silicon carbide I (with a particle size of 40 nm).

[0034] Comparative Example 5 The difference between this comparative example and Example 1 is that nano-alumina II (particle size is 300 nm) is used to replace nano-alumina I (particle size is 10 nm).

[0035] Comparative Example 6 The difference between this comparative example and Example 1 is that graphite II (particle size is 5 μm) is used to replace graphite I (particle size is 500 nm).

[0036] Comparative Example 7 The difference between this comparative example and Example 1 is that graphite III (particle size is 100 nm) is used to replace graphite I (particle size is 500 nm).

[0037] Performance Testing The above examples and comparative examples were subjected to the following tests: (1) Room temperature compressive strength test: Test according to the requirements of GB / T 4513.6-2017 Monolithic refractory materials Part 6: Determination of physical properties.

[0038] (2) Maximum ablation rate test: The test shall be conducted in accordance with the requirements of GJB 1597A-2018 Specification for Low Ablation Rate Refractory Concrete for Rocket Launch Pad Guide Channels.

[0039] (3) Refractoriness test: Test according to the requirements of GB / T 7322-2017 Test method for refractories.

[0040] Table 1 Performance test results

[0041] It can be seen from the above performance test results that Examples 1-3 have the best comprehensive performance, with a room temperature compressive strength (500°C / 3h) of 266~271MPa, a maximum ablation rate of 0.834~0.839mm / s, and a refractoriness of >1800°C; this is mainly because it strictly controls the particle size and mass ratio of the components, effectively improves the room temperature compressive strength of the material, reduces the ablation rate, and obtains good refractoriness.

[0042] Compared with Example 1, Comparative Example 1 uses mullite II (180 mesh) to replace mullite I (320 mesh). Since the mesh number of mullite II is not appropriate, the room temperature compressive strength of the material is reduced, the maximum ablation rate is increased, and the refractoriness is deteriorated; Compared with Example 1, the number of nano-silicon carbide I in the nano-scale superfine powder of Comparative Example 2 is changed to 25 parts, and the number of nano-alumina I is changed to 5 parts. Since the amount of nano-silicon carbide I is too much, the compounding effect is not good, the room temperature compressive strength of the material is reduced, the maximum ablation rate is increased, and the refractoriness is deteriorated; Compared with Example 1, the number of nano-silicon carbide I in the nano-scale superfine powder of Comparative Example 3 is changed to 10 parts, and the number of nano-alumina I is changed to 20 parts. Since the amount of nano-silicon carbide I is too small, the compounding effect is not good, the room temperature compressive strength of the material is reduced, the maximum ablation rate is increased, and the refractoriness is deteriorated; Compared with Example 1, Comparative Example 4 uses nano-silicon carbide II (particle size of 600nm) to replace Nano silicon carbide I (particle size is 40nm), due to the large particle size of nano silicon carbide II, the room temperature compressive strength of the material is reduced, the maximum ablation rate is increased, and the refractoriness is poor; compared with Example 1, comparative example 5 uses nano alumina II (particle size is 300nm) to replace nano alumina I (particle size is 10nm), due to the large particle size of nano alumina II, the room temperature compressive strength of the material is reduced, the maximum ablation rate is increased, and the refractoriness is poor; compared with Example 1, comparative example 6 uses graphite II (particle size is 5μm) to replace graphite I (particle size is 500nm), due to the large particle size of graphite II, the room temperature compressive strength of the material is reduced, the maximum ablation rate is increased, and the refractoriness is poor; compared with Example 1, comparative example 7 uses graphite III (particle size is 100nm) to replace graphite I (particle size is 500nm), due to the small particle size of graphite III, the room temperature compressive strength of the material is reduced, the maximum ablation rate is increased, and the refractoriness is poor.

Claims

1. An ultra-high temperature resistant high-speed jet material for a vehicle-mounted deflector at a space launch site, characterized in that: The composition comprises the following components in parts by weight: 36-40 parts of mullite, 26-30 parts of nano-grade 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 super 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-alumina is 10-20 nm; The particle size of the graphite is 500-800 nm.

2. A construction process for the ultra-high temperature resistant high-speed jet material for the vehicle-mounted deflector of a space launch site as claimed in claim 1, characterized in that: The following steps are involved: (1) Marking: Marking the dimensions of the anchors; (2) Welding and anchor welding quality inspection; (3) preparing the ultra-high temperature resistant high-speed jet material for the vehicle-mounted deflector of the space launch site, and then pouring it; (4) Vibration: Use an inserted vibrating rod to vibrate. Slowly insert the rod into the material layer to vibrate continuously and then slowly pull it out. (5) Demolding: demold the mold 12 to 24 hours after the castable is poured, and maintain the ambient temperature at 15 to 20°C; (6) Curing: After demolding, electric baking is performed for 5 to 6 days for curing.

3. The construction process according to claim 2, characterized in that: The preparation method of step (3) comprises: mixing the components according to weight proportions, and then adding water with a pH value of 6.5 to 8.5 and stirring for 6 to 8 minutes, wherein the amount of water added is 5 to 7%.

4. The construction process according to claim 2, characterized in that: The vibration time in step (4) is 5 to 10 minutes.

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