A cladding low thermal conductivity composite material sealing structure and a preparation method and application thereof

Abstract

The application provides a coated low-thermal-conductivity composite material sealing structure and a preparation method and application thereof. The coated low-thermal-conductivity composite material sealing structure comprises a composite structure formed by stacking a plurality of composite units, each of the composite units comprises inorganic fiber cotton, high-temperature silicone rubber and a corrugated metal rebound plate stacked in sequence, and a high-temperature fiber cloth is stitched on the outside of the composite structure. The coated low-thermal-conductivity composite material sealing structure has good sealing performance, high-temperature resistance, low thermal conductivity and rebound performance.

Description

Technical Field

[0001] This invention relates to the field of sealing structure technology, and in particular to a covered low thermal conductivity composite material sealing structure, its preparation method and application. Background Technology

[0002] The moving parts or connecting structures of high-speed aircraft in aerospace engineering, especially the aerodynamic and aerothermal interactions during high-speed flight, usually require a special sealing structure between these connecting contact surfaces to undertake the dual functions of high temperature and sealing. This sealing structure is called a high-temperature thermal sealing structure.

[0003] CN107587899A discloses a multi-layer sealing mechanism for an aircraft engine blade, comprising a hard rubber layer, a spring layer, a fiber cloth layer, and a brush layer connected sequentially from bottom to top. The fiber cloth layer consists of cotton and linen fiber cloth fixedly connected to the hard rubber layer, and the outer surface of the cotton and linen fiber cloth is covered with soft rubber. The brush layer includes several wire brushes fixedly connected to the fiber cloth layer, each wire brush being formed by several steel wires intertwined. In the above sealing mechanism, the hard rubber layer has poor high-temperature resistance, the fiber cloth layer has high permeability and poor resilience, and the spring layer has high thermal conductivity and limited sealing performance, making it impossible to simultaneously possess good sealing performance, high-temperature resistance, low thermal conductivity, and resilience.

[0004] In view of this, the present invention is proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a covered low thermal conductivity composite material sealing structure, its preparation method and application. This sealing structure has good sealing performance, high temperature resistance, low thermal conductivity and resilience.

[0006] This invention provides a covered low thermal conductivity composite material sealing structure, comprising a composite structure formed by stacking multiple composite units. Each composite unit comprises inorganic fiber cotton, high-temperature silicone rubber and corrugated metal rebound plate stacked sequentially, and high-temperature fiber cloth is wrapped and sewn on the outside of the composite structure.

[0007] Specifically, the inorganic fiber cotton is made of high-temperature fibers, such as at least one selected from glass fiber, basalt fiber, high-silica fiber, quartz fiber, mullite fiber, alumina fiber, and zirconium oxide fiber; the loose density of the inorganic fiber cotton is 1-300 g / cm³. 3 The thickness of inorganic fiber cotton is 1-3mm.

[0008] The high-temperature silicone rubber is selected from at least one of heat-cured silicone rubber, methyl silicone rubber, methyl vinyl silicone rubber, phenolphthalein silicone rubber, and fluorosilicone rubber; the high-temperature silicone rubber has a temperature resistance of ≥350℃ and a moisture permeability of 1-10 g / m³. 2 / 24h; the thickness of the high-temperature silicone rubber is 0.5-1.5mm.

[0009] The material of the corrugated metal spring plate is selected from at least one of copper and its alloys, titanium alloys, steel and iron alloys, nickel-based high-temperature alloys, niobium-based high-temperature alloys and molybdenum-based refractory alloys; the corrugation height of the corrugated metal spring plate is 0.3-1mm and the corrugation length is 1.5-2.5mm.

[0010] The high-temperature fiber cloth is made of high-temperature fibers, such as at least one selected from glass fiber, basalt fiber, high silica fiber, quartz fiber, mullite fiber, alumina fiber and zirconium oxide fiber; the thickness of the high-temperature fiber cloth is 0.01-2.00 mm.

[0011] The room temperature compression elastic deformation rate of the encapsulated low thermal conductivity composite material sealing structure of the present invention is 20-70%, and the room temperature compression resilience is ≥85%.

[0012] The method for preparing the encapsulated low thermal conductivity composite material sealing structure of the present invention includes the following steps:

[0013] S1: Inorganic fiber cotton, high-temperature silicone rubber and corrugated metal rebound plate are stacked sequentially to form a composite unit;

[0014] S2: Stacking multiple composite units to form a composite structure;

[0015] S3: A high-temperature fiber cloth is sewn over the outside of the composite structure to obtain a covered low thermal conductivity composite material sealing structure.

[0016] Specifically, inorganic fiber cotton can be made from high-temperature fiber monofilaments with a diameter of 1-15μm, for example, 6-8μm. The preparation of inorganic fiber cotton can be carried out by precursor sol-gel sintering, single-stage or multi-stage high-temperature roller blowing of melt, or other process methods.

[0017] High-temperature silicone rubber can be prepared by single-component or two-component heated vulcanization or room-temperature vulcanization processes; in addition, it can be further modified with iron oxide after heated vulcanization or room-temperature vulcanization.

[0018] Corrugated metal rebound sheets can be made by plastic forming of metal sheets with a thickness of 0.1-0.5mm.

[0019] High-temperature fiber cloth can be made from high-temperature fiber monofilaments with a diameter of 1-15μm, for example, 6-8μm.

[0020] The present invention also provides the application of the above-mentioned encapsulated low thermal conductivity composite material sealing structure in the preparation of moving parts or connecting structures of high-speed aircraft in aerospace engineering.

[0021] The encapsulated low thermal conductivity composite material sealing structure of the present invention overcomes the shortcomings of traditional high temperature sealing structures, such as poor heat resistance, high thermal conductivity, high permeability, and poor resilience, by encapsulating and stacking inorganic fiber cotton, high temperature silicone rubber, and corrugated metal rebound plate in high temperature fiber cloth. This is achieved by synergistically utilizing the encapsulation performance of high temperature fiber cloth, the low thermal conductivity of inorganic fiber cotton, the low permeability of high temperature silicone rubber, and the high resilience of corrugated metal rebound plate. Attached Figure Description

[0022] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the external structure of a covered low thermal conductivity composite material sealing structure.

[0024] Figure 2 This is a schematic diagram of the internal structure of a covered low thermal conductivity composite material sealing structure.

[0025] Explanation of reference numerals in the attached figures:

[0026] 1: Inorganic fiber cotton; 2: High-temperature silicone rubber; 3: Corrugated metal rebound plate; 4: High-temperature fiber cloth. Detailed Implementation

[0027] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0028] It should be noted that the terminology used herein is for the purpose of describing particular implementations only and is not intended to limit the exemplary implementations according to this application. As used herein, the singular form includes the plural form unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this description, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0029] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] Example 1

[0031] Combination Figure 1 , Figure 2 As shown, the encapsulated low thermal conductivity composite material sealing structure of this embodiment includes a composite structure formed by stacking three composite units. Each composite unit includes inorganic fiber cotton 1, high temperature silicone rubber 2 and corrugated metal rebound plate 3 stacked in sequence. High temperature fiber cloth 4 is wrapped and sewn on the outside of the composite structure.

[0032] The preparation method of the encapsulated low thermal conductivity composite material sealing structure in this embodiment includes the following steps:

[0033] 1) Selection and preparation of inorganic fiber cotton

[0034] Quartz fiber monofilaments with a diameter of 6-8μm were selected and quartz fiber cotton was made by melt blowing process to obtain inorganic fiber cotton with a single layer thickness of 2mm and a size of 100mm×10mm×2mm.

[0035] 2) Selection and preparation of high-temperature silicone rubber

[0036] A room temperature curing heat-resistant silicone rubber was prepared using α,ω-dihydroxypolydimethylphenylsiloxane as the matrix. The room temperature curing heat-resistant silicone rubber was modified with iron oxide to obtain a high temperature silicone rubber 2 with a single-layer thickness of 1 mm and a size of 100 mm × 10 mm × 1 mm.

[0037] 3) Selection and preparation of corrugated metal spring plates

[0038] A 0.1mm thick 304 stainless steel sheet is selected and pressed into a corrugated plate structure with a corrugation height of 0.6mm and a corrugation length of 2mm, thus producing a corrugated metal spring plate 3 with dimensions of 100mm×10mm×0.6mm.

[0039] 4) Selection and preparation of high-temperature fiber cloth

[0040] Quartz fiber monofilaments with a diameter of 6-8μm are selected, with a strength of 190TEX and a density of 350g / m². 2 A woven twill quartz fiber cloth with a thickness of 0.55mm is cut into a composite structure that can cover a size of 200mm×10mm×10mm, thus producing high-temperature fiber cloth 4.

[0041] 5) Preparation of composite units

[0042] The inorganic fiber cotton 1 with dimensions of 100mm×10mm×2mm, the high-temperature silicone rubber 2 with dimensions of 100mm×10mm×1mm, and the corrugated metal rebound plate 3 with dimensions of 100mm×10mm×0.6mm are stacked in sequence to form a composite unit; three of the above composite units are stacked to form a composite structure.

[0043] 6) Preparation of encapsulated low thermal conductivity composite material sealing structure

[0044] The composite structure is placed on the cut high-temperature fiber cloth 4, and then placed in a mold with a size of 200mm×10mm×10mm. After covering, the edges are sewn with quartz thread to obtain the covered low thermal conductivity composite material sealing structure.

[0045] Testing showed that the apparent density of the encapsulated low thermal conductivity composite material sealing structure prepared in this embodiment is 0.3 g / cm³. 3 The room temperature compression elastic deformation rate is 33%, the room temperature compression rebound rate is 87%, and the thermal conductivity is approximately 0.15 W / (m·K). Environmental testing at 750℃ for 50 hours has demonstrated that the above-mentioned encapsulated low thermal conductivity composite material sealing structure exhibits excellent sealing performance.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A covered low thermal conductivity composite material sealing structure, characterized in that, It includes a composite structure formed by stacking multiple composite units, each of which includes inorganic fiber cotton, high-temperature silicone rubber and corrugated metal rebound plate stacked in sequence, and high-temperature fiber cloth is sewn on the outside of the composite structure. The inorganic fiber cotton is made from at least one of basalt fiber, high silica fiber, quartz fiber, mullite fiber, alumina fiber and zirconium oxide fiber. The thickness of the inorganic fiber cotton is 1-3 mm. The inorganic fiber cotton is made by melt blowing high-temperature fiber monofilaments. The diameter of the high-temperature fiber monofilaments is 1-15 μm. The high-temperature silicone rubber is made of at least one of methyl silicone rubber, methyl vinyl silicone rubber and fluorosilicone rubber. The thickness of the high-temperature silicone rubber is 0.5-1.5 mm, and the temperature resistance of the high-temperature silicone rubber is ≥350℃. The material of the corrugated metal spring plate is selected from at least one of copper and its alloys, titanium alloys, nickel-based high-temperature alloys and molybdenum-based refractory alloys. The corrugation height of the corrugated metal spring plate is 0.3-1 mm, the corrugation length is 1.5-2.5 mm, and the corrugated metal spring plate is made by plastic forming of metal plate with a thickness of 0.1-0.5 mm. The high-temperature fiber cloth is made of at least one of basalt fiber, high silica fiber, quartz fiber, mullite fiber, alumina fiber and zirconium oxide fiber, and the thickness of the high-temperature fiber cloth is 0.55-2.00 mm.

2. The encapsulated low thermal conductivity composite material sealing structure according to claim 1, characterized in that, The moisture permeability of high-temperature silicone rubber is 1-10 g / (m²). 2 •24h).

3. The encapsulated low thermal conductivity composite material sealing structure according to claim 1, characterized in that, The room temperature compression elastic deformation rate of this encapsulated low thermal conductivity composite sealing structure is 20-70%, and the room temperature compression resilience is ≥85%.

4. The method for preparing the encapsulated low thermal conductivity composite material sealing structure according to any one of claims 1-3, characterized in that, Includes the following steps: S1: Inorganic fiber cotton, high-temperature silicone rubber and corrugated metal rebound plate are stacked sequentially to form a composite unit; S2: Stacking multiple composite units to form a composite structure; S3: A high-temperature fiber cloth is sewn over the outside of the composite structure to obtain a covered low thermal conductivity composite material sealing structure.

5. The preparation method according to claim 4, characterized in that, High-temperature fiber cloth is made from high-temperature fiber monofilaments, with a diameter of 1-15 μm.

6. The application of the encapsulated low thermal conductivity composite material sealing structure according to any one of claims 1-3 in the manufacture of moving parts or connecting structures for high-speed aircraft in aerospace engineering.

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