A method for preparing a 1650°C resistant flexible alumina continuous fiber thermal insulation tile

Abstract

The present invention discloses a method for preparing a 1650°C resistant flexible alumina continuous fiber thermal insulation tile, which belongs to the technical field of high-temperature alumina materials. The 1650°C resistant flexible alumina continuous fiber thermal insulation tile of the present invention comprises a flexible alumina thermal insulation tile and a surface coating. The thermal insulation tile is a sandwich structure, which is prepared by stitching the surface layer of alumina continuous fiber cloth and the middle layer of alumina continuous fiber felt. The coating component A is composed of a filler and a radiation agent of component B. The component A is one or more of MoSi2, silicon carbide or silicon boride. The component B is SiO2 powder, metal silicon powder, silicon carbide fiber, and alumina fiber. The 1650°C resistant thermal insulation tile of the present invention has long-term high temperature resistance, excellent durability, special-shaped molding performance, high radiation performance and moisture-proof performance; the present invention also provides a preparation method with a simple process.

Description

Technical Field

[0001] The invention relates to a method for preparing a 1650°C resistant flexible alumina continuous fiber thermal insulation tile, and belongs to the technical field of high-temperature alumina materials. Background Art

[0002] In recent years, high Mach number aircraft have been vigorously developed in the field of aerospace. When ultra-high-speed aircraft enter the atmosphere, there is a severe aerodynamic heating effect due to high-speed friction. Faced with such a harsh aerodynamic heating environment, how to adapt to temperatures above 1650°C, reduce the heat transferred from the surface of the aircraft to the interior, and ensure the safety of the main structure and internal instruments and equipment during long-term flight of the aircraft has become a hot topic of current research.

[0003] Thermal insulation tiles are a kind of high-efficiency thermal protection material with light weight, high porosity, low density, and the characteristics of heat insulation, impact resistance, and maintaining the aerodynamic shape of the aircraft. They can be used in large thermal protection areas such as the front, rear, and wings of the aircraft. They account for a large proportion of the thermal protection structure of new aircraft and are the main body of aircraft thermal protection and thermal control issues. However, the current thermal insulation tiles are mostly made of carbon-based materials or quartz fibers, which cannot meet the requirements of use above 1650°C. On the other hand, the current thermal insulation tiles are mainly rigid structures, with a narrow range of durability and use environments, and cannot meet the requirements of complex special-shaped components.

[0004] Chinese patent CN 108455978A discloses a rigid thermal insulation tile multilayer composite material, which has a 4-layer structure and a relatively complex design; the toughened alumina dense ceramic layer composition on its surface is composed of multiple components, with a variety of raw materials and a cumbersome processing process; and the thermal insulation tile is a rigid material with a narrow application range and can only withstand a high temperature of 1600°C. Summary of the invention

[0005] In order to solve at least one of the above problems, the present invention provides a 1650°C resistant flexible alumina continuous fiber thermal insulation tile, the alumina continuous fiber thermal insulation tile comprises a flexible alumina thermal insulation tile and a surface coating. The thermal insulation tile is a sandwich structure, which is prepared by stitching the surface layer of alumina continuous fiber cloth and the middle layer of alumina continuous fiber felt. The surface coating of the alumina continuous fiber cloth is composed of component A filler and component B radiation agent. The component A filler is one or more of MoSi2, silicon carbide or silicon boride. The component B radiation agent is one or more of SiO2 powder, metal silicon powder, silicon carbide fiber, and alumina fiber. The 1650°C high temperature resistant thermal insulation tile of the present invention has long-term high temperature resistance, excellent durability, special-shaped molding performance, high radiation performance and moisture-proof performance. The present invention also provides a method for preparing alumina continuous fiber thermal insulation tile with a simple process.

[0006] The first object of the present invention is to provide a method for preparing a 1650°C resistant flexible alumina continuous fiber thermal insulation tile, comprising the following steps:

[0007] S1, weaving alumina fiber on a loom to obtain alumina continuous fiber cloth;

[0008] S2, preparing alumina continuous fiber felt using alumina continuous fiber chopped yarn by air-laid and needle punching / twisting process;

[0009] S3, arranging the thicker and thinner continuous alumina fibers on the upper and lower surfaces of the alumina fiber felt, and sewing the alumina continuous fiber cloth and the alumina continuous fiber felt into an alumina continuous fiber insulation tile by a sewing process;

[0010] S4, mixing component A filler and component B radiation agent uniformly and grinding into powder;

[0011] S5, mixing the powder prepared in S4 with water to prepare a slurry and evenly coating the slurry on the surface of the alumina continuous fiber insulation tile coating, scraping and drying;

[0012] S6, high temperature firing to produce 1650℃ resistant flexible alumina continuous fiber insulation tile.

[0013] In one embodiment of the present invention, the upper and lower surface layers of alumina continuous fiber cloth are one of plain weave, twill weave, satin weave, three-dimensional orthogonal weave, layer-by-layer angle interlocking, multi-layer stitching, and through-thickness angle interlocking.

[0014] In one embodiment of the present invention, the alumina continuous fiber is one of 100tex, 200tex, and 320tex.

[0015] In one embodiment of the present invention, the surface density of the alumina continuous fiber cloth is 200 g / m 2 ~1200g / m 2 .

[0016] In one embodiment of the present invention, the thickness of the alumina continuous fiber cloth is 0.2 mm to 20 mm.

[0017] In one embodiment of the present invention, the tensile strength of the alumina continuous fiber cloth is 500 MPa~1000 MPa.

[0018] In one embodiment of the present invention, the volume fraction of the intermediate layer of alumina continuous fiber felt in the alumina continuous fiber insulation tile is 20% to 40%.

[0019] In one embodiment of the present invention, the length of the alumina continuous fiber chopped yarn of the intermediate layer of alumina continuous fiber felt is 30 mm to 50 mm.

[0020] In one embodiment of the present invention, the surface density of the intermediate layer of continuous alumina fiber felt is 100 g / m 2 ~210 g / m 2 .

[0021] In one embodiment of the present invention, the thickness of the intermediate layer of continuous alumina fiber felt is 2 mm to 100 mm.

[0022] In one embodiment of the present invention, the thermal conductivity of the intermediate layer of continuous alumina fiber felt is 0.01 W / m·K to 0.1 W / m·K.

[0023] In one embodiment of the present invention, the suture rope of the suture process in step S3 has 9 strands, a twist of 175 twists, a fiber fineness of 72 tex, and a suture density of 4 strands / cm.

[0024] In one embodiment of the present invention, the weight ratio of component A to component B in the coating is 40:65.

[0025] In one embodiment of the present invention, component A is prepared by mixing MoSi2 and silicon carbide.

[0026] In one embodiment of the present invention, the mass ratio of MoSi2 and silicon carbide in component A is 1:1.

[0027] In one embodiment of the present invention, component B is prepared by mixing SiO2 powder, metallic silicon powder, silicon carbide fiber and alumina fiber.

[0028] In one embodiment of the present invention, the mass fraction ratio of silicon to aluminum in component B is 1:1.5.

[0029] In one embodiment of the present invention, the mass ratio of SiO2 powder and alumina fiber in component B is 35:35; the mixed mass ratio of metallic silicon powder and alumina fiber is 20:35; and the mass ratio of silicon carbide fiber and alumina fiber is 16:35.

[0030] In one embodiment of the present invention, the thickness ratio of the alumina continuous fiber cloth of the upper layer and the lower layer of the thermal insulation tile is 1.25:1.

[0031] In one embodiment of the present invention, the drying temperature in step S5 is 55°C and the sintering temperature is 1500°C.

[0032] The second purpose of the present invention is to obtain the thermal insulation tile by the method for preparing the flexible alumina continuous fiber thermal insulation tile resistant to 1650°C.

[0033] The third object of the present invention is to use the 1650°C resistant flexible alumina continuous fiber thermal insulation tile described in the present invention in aerospace vehicles.

[0034] Beneficial effects achieved by the present invention:

[0035] (1) The present invention is easy to manufacture, and only uses alumina continuous fiber fabric, alumina continuous fiber felt and an outer coating to prepare a 1650°C resistant flexible alumina continuous fiber insulation tile.

[0036] (2) The present invention has a simple structure and adopts a combined structure of alumina continuous fiber fabric and fiber felt. It has the characteristics of flexibility, lighter weight, and designability in complex environments.

[0037] (3) The 1650°C resistant flexible alumina continuous fiber thermal insulation tile produced by the present invention has good durability and long-term high temperature resistance. It can work for 100 hours in an environment of 1650°C. It has good dimensional stability and no quality change in high and low temperature cycles and ablation experiments. The thermal insulation performance does not change much, and the strength is slightly improved. It only shrinks in volume when it is thermally cycled 8 times at 50-1600°C, and the volume shrinkage rate is 2%. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 The present invention is a schematic diagram of the structure of a 1650°C resistant flexible alumina continuous fiber thermal insulation tile and coating, wherein structure 1 is a coating prepared from component A and component B, structure 2 is an alumina continuous fiber cloth layer, and structure 3 is an alumina fiber felt. DETAILED DESCRIPTION

[0039] The preferred embodiments of the present invention are described below. It should be understood that the embodiments are for better explaining the present invention and are not used to limit the present invention.

[0040] Source of raw materials: MoSi2, silicon carbide, silicon boride, SiO2 powder, metallic silicon powder, and silicon carbide fiber were all purchased from Jinzhou Haixin Metal Materials Co., Ltd.

[0041] Performance test: thermal conductivity is tested according to standard ISO 22007-2:2022; compressive strength is tested according to standard ASTMD3410 / M-03; tensile strength is tested according to standard GJB 6475—2008; volume shrinkage is tested according to standard ASTM C326-2009.

[0042] Example 1

[0043] A 1650°C resistant flexible alumina continuous fiber insulation tile, such as Figure 1 As shown, the 1650°C resistant flexible alumina continuous fiber thermal insulation tile comprises a surface coating 1, a continuous alumina fiber cloth 2, and an alumina fiber felt 3.

[0044] The continuous alumina fiber cloth is a two-dimensional satin fabric, and the specific molding process is: using alumina fiber with a fineness of 320tex, in a two-dimensional weaving device, using five three-fly satin structures, the warp density is 28 strands / 10cm, the weft density is 22 strands / 10cm, the machine width is 420mm, and the side structure is 20mm, and a two-dimensional satin fabric with a thickness of 0.5mm, a width of 400mm, and a length of 500mm is prepared. Using alumina fiber with a fineness of 320tex, in a two-dimensional weaving device, using five three-fly satin structures, the warp density is 26 strands / 10cm, the weft density is 20 strands / 10cm, the machine width is 420mm, and the side structure is 20mm, and a two-dimensional satin fabric with a thickness of 0.4mm, a width of 400mm, and a length of 500mm is prepared.

[0045] Alumina fiber felt chopped yarn length 50mm, air-laid, needle-punched / twisted process, needle-punched felt density 180 g / m 2 , thickness is 10mm.

[0046] Continuous alumina fibers with a thickness of 0.5 mm and 0.4 mm are arranged on the upper and lower surfaces of the alumina fiber mat, respectively. The surface continuous alumina fiber cloth and the alumina fiber felt are sewn together using a suturing process. The suturing rope is 8-ply, with a twist of 170 and a fiber fineness of 65 tex. The number of suturing stitches is 6 / cm.

[0047] Then, the surface slurry is prepared and applied to the surface of the thermal insulation tile. After burning, the alumina continuous fiber thermal insulation tile resistant to high temperature of 1650°C is obtained. The specific steps are as follows:

[0048] (1) First, MoSi2 and silicon carbide are mixed in a mass ratio of 1:1 to obtain component A, and then SiO2 powder, metal silicon powder, silicon carbide fiber, and alumina fiber are mixed in a mass ratio of silicon to aluminum of 1:1.5 to obtain component B. Then, component A and component B are mixed in a mass ratio of 40:60, finely ground, and stirred to form a powder;

[0049] (2) The powder obtained in step (1) and water are mixed in a mass ratio of 1:1 to form a slurry, and then the slurry is applied to the surface of the thermal insulation tile with a coating thickness of 0.5 mm, scraped and dried at a drying temperature of 65°C and a drying time of 8 hours;

[0050] (3) The thermal insulation tile dried in step (2) is calcined at 1600°C for 5 hours to obtain a thermal insulation tile resistant to high temperature of 1650°C.

[0051] Table 1 Various properties of 1650℃ resistant flexible alumina continuous fiber insulation tile

[0052]

[0053] The room temperature thermal conductivity of the 1650°C resistant flexible alumina continuous fiber thermal insulation tile of the present invention is 0.048W / m·K, the thermal conductivity of the 1650°C resistant flexible alumina continuous fiber thermal insulation tile under 1000°C thermal conditions is 0.08W / m·K, the compressive strength is 1.2MPa, and the tensile strength is 0.7MPa. The high temperature thermal insulation tile has excellent reusability under 50-1600°C cycle test conditions, good dimensional stability and no quality change in high and low temperature cycles and ablation experiments, little change in thermal insulation performance, and slightly improved strength. Volume shrinkage occurs only when the thermal cycle is 50-1600°C for 8 times, and the volume shrinkage rate is 2%.

[0054] Example 2

[0055] Referring to Example 1, the continuous alumina fiber cloth was changed from satin to twill, three-dimensional orthogonal weave, and woven, respectively, while other parameters remained unchanged.

[0056] Table 2 Various properties of alumina continuous fiber insulation tiles with different organizational structures

[0057]

[0058] Example 3

[0059] Referring to Example 1, the thickness ratio (upper: lower) of the continuous alumina fiber cloth was changed to 1:1, 1.5:1. Other parameters remained unchanged.

[0060] Table 3 Performance of alumina continuous fiber insulation tiles with different fiber cloth thickness ratios

[0061]

[0062] Comparative Example 1

[0063] Referring to Example 1, the number of strands of the suture thread was changed to 3 and 10 respectively, while other parameters remained unchanged.

[0064] Table 4 Various properties of alumina continuous fiber insulation tiles with different ply numbers of stitching lines

[0065]

[0066] Comparative Example 2

[0067] Referring to Example 1, the ratio of components A and B was changed to 10:90 and 60:40, while other parameters remained unchanged.

[0068] Table 5 Performance of alumina continuous fiber insulation tiles with different AB component ratios

[0069]

[0070] Comparative Example 3

[0071] Referring to Example 1, the mass fraction ratio of silicon to aluminum in component B was changed to 1:1 or 2:1, while other parameters remained unchanged.

[0072] Table 6 Properties of alumina continuous fiber insulation tiles of component B prepared with different mass fraction ratios of silicon to aluminum

[0073]

[0074] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Anyone familiar with this technology can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the definition of the claims.

Claims

1. A method for preparing a 1650°C resistant flexible alumina continuous fiber thermal insulation tile, characterized in that: The specific steps include: S1, weaving alumina fiber on a loom to obtain alumina continuous fiber cloth; S2, preparing alumina fiber felt using alumina continuous fiber chopped yarn by air-laid and needle-punched process; S3, arranging the thicker and thinner alumina continuous fiber cloths on the upper and lower surfaces of the alumina fiber felt, respectively, and using a stitching process to make the alumina continuous fiber cloth and the alumina fiber felt into an alumina continuous fiber insulation tile; S4, mixing component A filler and component B radiation agent uniformly and grinding into powder; S5, mixing the powder prepared in S4 with water to prepare a slurry and evenly coating the slurry on the surface of the alumina continuous fiber insulation tile, scraping and drying; S6, high temperature firing to produce 1650℃ resistant flexible alumina continuous fiber insulation tile; The alumina fibers described in S1 are 100 tex - 500 tex; Alumina continuous fiber cloth density ranges from 200-800 g / m 2 ; The tensile strength of alumina continuous fiber cloth is 500 MPa~1000 MPa; The density of the alumina fiber felt in S2 is 0.2-1.0 g / cm 3 , thermal conductivity is 0.01 W / m·K~0.1 W / m·K, thickness is 2-25 mm; chopped yarn length is 30 mm - 60 mm, needle punching density is 80 g / m 2 -300 g / m 2 ; The thickness ratio of the upper and lower layers of alumina continuous fiber cloth in S3 is 1.25:1; The component A in S4 is MoSi2 and silicon carbide, with a mass ratio of 1:1; the component B is SiO2 powder, metallic silicon powder, silicon carbide fiber, and alumina fiber, and the mass fraction ratio of silicon to aluminum in component B is 1:1.5; the weight ratio of component A to component B is 40:

60.

2. The preparation method according to claim 1, characterized in that: The alumina continuous fiber cloth described in S1 is one of plain weave, twill weave, satin weave, three-dimensional orthogonal weave, layer-by-layer angle interlocking, multi-layer stitching, and through-thickness angle interlocking.

3. The preparation method according to claim 1, characterized in that: The suture rope of the suture process described in S3 has 6-10 strands, a twist of 160-180 twists, a fiber fineness of 60-80 tex, and a suture density of 3-10 strands / cm.

4. A 1650°C resistant flexible alumina continuous fiber insulation tile, characterized in that: The 1650°C resistant flexible alumina continuous fiber thermal insulation tile is made according to the method according to any one of claims 1 to 3.

5. Application of the 1650°C resistant flexible alumina continuous fiber thermal insulation tile according to claim 4 in thermal protection materials for aircraft surfaces, thermal protection materials for ultra-high temperature chemical reactors, ultra-high temperature thermal protection materials for nuclear reactors, and thermal insulation linings for ultra-high temperature kilns.

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