Coated low-thermal-conductivity composite material sealing structure and preparation method and application thereof

Abstract

The invention provides a coated low-thermal-conductivity composite material sealing structure as well as a preparation method and application thereof. The coated low-thermal-conductivity composite material sealing structure comprises a composite structure formed by stacking multiple layers of composite units, each layer of composite unit comprises inorganic fiber cotton, high-temperature silicone rubber and a corrugated metal rebound plate which are sequentially stacked, and high-temperature fiber cloth is coated and sewn outside the composite structure. The coated low-heat-conductivity composite material sealing structure has good sealing performance, high-temperature resistance, low heat conductivity and rebound resilience.

Description

Technical Field

[0001] The present invention relates to the technical field of sealing structures, and in particular to a coated low thermal conductivity composite material sealing structure and a preparation method and application thereof. Background Art

[0002] The active parts or connection structures of high-speed aircraft in aerospace engineering, especially the aerodynamic and aerothermal interactions during high-speed flight, usually require special sealing structures between these connection contact surfaces to assume 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 aviation engine blade, comprising a hard rubber layer, a spring layer, a fiber cloth layer and a brush layer connected in sequence from bottom to top, wherein the fiber cloth layer comprises a cotton and linen fiber cloth fixedly connected to the hard rubber layer, the outer surface of the cotton and linen fiber cloth is covered with soft rubber, and the brush layer comprises a plurality of steel wire brushes fixedly connected to the fiber cloth layer, each of which is formed by a plurality of steel wire strips intertwined with each other. In the above sealing mechanism, the hard rubber layer has poor high temperature tolerance, the fiber cloth layer has high permeability and poor resilience, and the spring layer has high thermal conductivity and limited sealing performance, and cannot have good sealing performance, high temperature resistance, low thermal conductivity and resilience at the same time.

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

[0005] The object of the present invention is to provide a coated low thermal conductivity composite material sealing structure and a preparation method and application thereof, wherein the sealing structure has good sealing performance, high temperature resistance, low thermal conductivity and resilience.

[0006] The present invention provides a wrapped low thermal conductivity composite material sealing structure, comprising a composite structure formed by stacking multiple layers of composite units, each layer of the composite unit comprising inorganic fiber cotton, high temperature silicone rubber and corrugated metal rebound plates stacked in sequence, and high temperature fiber cloth is wrapped and sewn on the outside of the composite structure.

[0007] Specifically, the material of the inorganic fiber cotton is high temperature fiber, for example, at least one selected from glass fiber, basalt fiber, high silica fiber, quartz fiber, mullite fiber, alumina fiber and zirconia fiber; the bulk density of the inorganic fiber cotton is 1-300g / cm 3 ; The thickness of inorganic fiber cotton is 1-3mm.

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

[0009] The material of the corrugated metal rebound 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 rebound plate is 0.3-1mm, and the corrugation length is 1.5-2.5mm.

[0010] The material of the high temperature fiber cloth is high temperature fiber, for example, at least one selected from glass fiber, basalt fiber, high silica fiber, quartz fiber, mullite fiber, alumina fiber and zirconia 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 coated low thermal conductivity composite material sealing structure of the present invention is 20-70%, and the room temperature compression rebound rate is ≥85%.

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

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

[0014] S2: stacking multiple layers of composite units to form a composite structure;

[0015] S3: high temperature fiber cloth is coated and sewed on the outside of the composite structure to obtain a coated low thermal conductivity composite material sealing structure.

[0016] Specifically, the inorganic fiber cotton can be made from high-temperature fiber monofilaments, the diameter of the high-temperature fiber monofilaments is 1-15μm, for example, 6-8μm; the preparation method of the inorganic fiber cotton can adopt precursor sol-gel sintering, single-stage or multi-stage roller high-temperature blowing process of the melt or other process methods.

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

[0018] The corrugated metal rebound plate can be manufactured by plastic forming of a metal plate, and the thickness of the metal plate is 0.1-0.5 mm.

[0019] The high temperature fiber cloth can be made of high temperature fiber monofilaments, and the diameter of the high temperature fiber monofilaments is 1-15 μm, for example, 6-8 μm.

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

[0021] The coated low thermal conductivity composite material sealing structure of the present invention coats and stacks inorganic fiber cotton, high temperature silicone rubber and corrugated metal rebound plate in high temperature fiber cloth, and synergistically utilizes the coating and packaging performance of the high temperature fiber cloth, the low thermal conductivity of the inorganic fiber cotton, the low permeability of the high temperature silicone rubber and the high rebound characteristics of the corrugated metal rebound plate, thereby overcoming the shortcomings of traditional high temperature sealing structures such as poor heat resistance, high thermal conductivity, high permeability and poor rebound performance, so that the coated low thermal conductivity composite material sealing structure has good sealing performance, high temperature resistance, low thermal conductivity and rebound performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 It is a schematic diagram of the external structure of the wrapped low thermal conductivity composite material sealing structure;

[0024] Figure 2 Schematic diagram of the internal structure of the wrapped low thermal conductivity composite material sealing structure.

[0025] Description of reference numerals:

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

[0027] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0028] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form also includes the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this description, it indicates 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 in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. 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.

[0030] Example 1

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

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

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

[0034] Quartz fiber monofilaments with a diameter of 6-8 μm are selected and made into quartz fiber cotton by a melt blowing process, thereby obtaining a single-layer inorganic fiber cotton 1 with a thickness of 2 mm and a size of 100 mm×10 mm×2 mm.

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

[0036] A room temperature curing heat-resistant silicone rubber was prepared using α,ω dihydroxy polydimethylphenylsiloxane as a matrix, and the room temperature curing heat-resistant silicone rubber was subjected to iron oxide modification treatment 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 rebound plate

[0038] A 304 stainless steel sheet with a thickness of 0.1 mm was selected and pressed into a corrugated plate structure with a corrugation height of 0.6 mm and a corrugation length of 2 mm, that is, a corrugated metal rebound plate 3 with a size of 100 mm×10 mm×0.6 mm was obtained.

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

[0040] Select quartz fiber monofilament with a diameter of 6-8μm, 190TEX, 350g / m 2 The woven twill quartz fiber cloth, with a thickness of 0.55 mm, is cut into a composite structure capable of covering a size of 200 mm×10 mm×10 mm, namely, the high-temperature fiber cloth 4 is obtained.

[0041] 5) Preparation of composite unit

[0042] The inorganic fiber cotton 1 with a size of 100mm×10mm×2mm, the high-temperature silicone rubber 2 with a size of 100mm×10mm×1mm, and the corrugated metal rebound plate 3 with a size of 100mm×10mm×0.6mm prepared above 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 coated low thermal conductivity composite 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 200 mm×10 mm×10 mm. After coating, the edges are sewn with quartz thread to obtain a coated low thermal conductivity composite material sealing structure.

[0045] After testing, the apparent density of the sealing structure of the coated low thermal conductivity composite material sealing structure prepared in this embodiment is 0.3g / cm 3 The room temperature compression elastic deformation rate is 33%, the room temperature compression rebound rate is 87%, and the thermal conductivity is about 0.15W / (m·K). The 750℃, 50h environmental test proves that the sealing performance of the above-mentioned coated low thermal conductivity composite material sealing structure is good.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements 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 coated low thermal conductivity composite material sealing structure, characterized in that: It comprises a composite structure formed by stacking multiple layers of composite units, each layer of composite units comprises inorganic fiber cotton, high-temperature silicone rubber and corrugated metal rebound plates stacked in sequence, and the exterior of the composite structure is covered and sewn with high-temperature fiber cloth.

2. The wrapped low thermal conductivity composite material sealing structure according to claim 1, characterized in that: The material of inorganic fiber cotton is high temperature fiber; Preferably, the high temperature fiber is selected from at least one of glass fiber, basalt fiber, high silica fiber, quartz fiber, mullite fiber, alumina fiber and zirconia fiber; Preferably, the bulk density of the inorganic fiber cotton is 1-300 g / cm 3 ; Preferably, the thickness of the inorganic fiber wool is 1-3 mm.

3. The wrapped low thermal conductivity composite material sealing structure according to claim 1, characterized in that: The material of the high temperature silicone rubber is selected from at least one of heat-vulcanized silicone rubber, methyl silicone rubber, methyl vinyl silicone rubber, phenolphthalein silicone rubber and fluorosilicone rubber; Preferably, the temperature resistance of high temperature silicone rubber is ≥350°C and the moisture permeability is 1-10g / m 2 / 24h; Preferably, the thickness of the high temperature silicone rubber is 0.5-1.5 mm.

4. The wrapped low thermal conductivity composite material sealing structure according to claim 1, characterized in that: The material of the corrugated metal rebound 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; Preferably, the corrugation height of the corrugated metal rebound plate is 0.3-1 mm, and the corrugation length is 1.5-2.5 mm.

5. The wrapped low thermal conductivity composite material sealing structure according to claim 1, characterized in that: The material of inorganic fiber cotton is high temperature fiber; Preferably, the high temperature fiber is selected from at least one of glass fiber, basalt fiber, high silica fiber, quartz fiber, mullite fiber, alumina fiber and zirconia fiber; Preferably, the high temperature fiber cloth has a thickness of 0.01-2.00 mm.

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

7. The method for preparing a coated low thermal conductivity composite material sealing structure according to any one of claims 1 to 6, characterized in that: The steps include: S1: Inorganic fiber cotton, high temperature silicone rubber and corrugated metal rebound plate are stacked in sequence to form a composite unit; S2: stacking multiple layers of composite units to form a composite structure; S3: high temperature fiber cloth is coated and sewed on the outside of the composite structure to obtain a coated low thermal conductivity composite material sealing structure.

8. The preparation method according to claim 7, characterized in that: The inorganic fiber cotton and the high-temperature fiber cloth are respectively made of high-temperature fiber monofilaments, and the diameter of the high-temperature fiber monofilaments is 1-15 μm.

9. The preparation method according to claim 7, characterized in that: The corrugated metal rebound plate is made by plastic forming of a metal plate, and the thickness of the metal plate is 0.1-0.5 mm.

10. Use of the wrapped low thermal conductivity composite material sealing structure according to any one of claims 1 to 6 in preparing movable parts or connection structures of high-speed aircraft in aerospace engineering.

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