阅读说明：本技术 一种高效隔热夹层结构气凝胶防热材料及其制备方法 (Efficient heat-insulation sandwich structure aerogel heat-proof material and preparation method thereof ) 是由 苏力军 赵佳明 徐沛 宋寒 李文静 杨洁颖 于 2020-06-24 设计创作，主要内容包括：本发明涉及一种高效隔热夹层结构气凝胶防热材料及其制备方法。防热材料包括气凝胶复合材料基体：气凝胶复合材料基体包括多层功能梯度薄毡和弥散在多层功能梯度薄毡内部和/或表层的气凝胶；多层功能梯度薄毡包括多层无机纤维薄层材料,层与层之间夹有红外反射膜材料,通过Z向针刺复合为一体结构,无机纤维薄层材料的层数为n,红外反射膜材料的层数为n-1,n≥2；无机纤维编织物,铺设于气凝胶复合材料基体上下表面,通过缝合与气凝胶复合材料基体实现固定；和表面陶瓷面板,通过将固定有无机纤维编织物的气凝胶复合材料基体浸渍陶瓷前驱体而形成。该防热材料具有优异的隔热性能和抗冲刷性能,可应用在内隔热和外防热领域。(The invention relates to an efficient heat-insulating sandwich structure aerogel heat-proof material and a preparation method thereof. The heat shielding material comprises an aerogel composite matrix: the aerogel composite material matrix comprises a plurality of layers of functionally graded mats and aerogels dispersed in the inner parts and/or the surface layers of the functionally graded mats; the multilayer functionally graded thin felt comprises a plurality of layers of inorganic fiber thin layers, infrared reflection film materials are clamped between the layers, the layers are compounded into an integral structure through Z-direction needling, the number of the inorganic fiber thin layers is n, the number of the infrared reflection film materials is n-1, and n is more than or equal to 2; the inorganic fiber braided fabric is laid on the upper surface and the lower surface of the aerogel composite material matrix and is fixed with the aerogel composite material matrix through sewing; and a surface ceramic panel formed by impregnating a ceramic precursor with an aerogel composite matrix to which an inorganic fiber woven fabric is fixed. The heat-proof material has excellent heat-insulating property and anti-scouring property, and can be applied to the fields of internal heat insulation and external heat insulation.)

1. An efficient heat insulation sandwich structure aerogel heat protection material is characterized by comprising:

aerogel composite matrix: the aerogel composite material matrix comprises a plurality of layers of functionally graded mats and aerogels dispersed in the inner parts and/or the surface layers of the plurality of layers of functionally graded mats; the multilayer functionally graded thin felt comprises a plurality of layers of inorganic fiber thin layers, infrared reflection film materials are clamped between the layers, the layers are compounded into an integral structure through Z-direction needling, the number of the inorganic fiber thin layers is n, the number of the infrared reflection film materials is n-1, and n is more than or equal to 2;

inorganic fiber woven fabric: the aerogel composite material matrix is paved on the upper surface and the lower surface of the aerogel composite material matrix and is fixed with the aerogel composite material matrix through sewing;

surface ceramic panel: is formed by impregnating a ceramic precursor with the aerogel composite matrix to which the inorganic fiber woven fabric is fixed.

2. The material according to claim 1,

the inorganic fiber thin layer material is a material in a fiber felt form, and is preferably one or more of a zirconia fiber felt, an alumina fiber felt, a mullite fiber felt, a quartz fiber felt, an alumina silicate fiber felt, a high silica fiber felt, a basalt rock wool fiber felt and a glass fiber felt;

further preferably, the thickness of the fiber felt is 1-10 mm;

further preferably, the fiber mat has a density of 0.05 to 0.25g/cm³Most preferably 0.10 to 0.15g/cm³。

3. Material according to claim 1 or 2,

the infrared reflection film material is any one or more of aluminum foil, silicon carbide fiber cloth, carbon fiber cloth and silicon nitride fiber cloth.

4. Material according to any one of claims 1 to 3,

the aerogel is SiO₂Aerogel, Al₂O₃Aerogel, ZrO₂Any one or more of aerogels, ceramic aerogels; optionally, the aerogel is obtained by sol-gel, supercritical drying the multilayer functionally graded mat with an aerogel precursor; further preferably, the mass concentration of the aerogel precursor is 5-40%, most preferably 15-25%.

5. Material according to any one of claims 1 to 4,

the needling density of the Z-direction needling is 5-50 needles/cm²More preferably 20 to 40 needles/cm²。

6. Material according to any one of claims 1 to 5,

the inorganic fiber braided fabric is any one or more of alumina fiber cloth, mullite fiber cloth and quartz fiber cloth; optionally, the structure of the inorganic fiber braided fabric is plain cloth or satin cloth;

further preferably, the thickness of the woven inorganic fiber fabric laid on the upper surface of the aerogel composite substrate is 0.5 to 3mm, and the thickness of the woven inorganic fiber fabric laid on the lower surface of the aerogel composite substrate is 0.1 to 1 mm.

7. Material according to any one of claims 1 to 6,

the ceramic precursor is SiO₂Precursor and Al₂O₃Precursor, ZrO₂Any one or more of the precursors;

preferably, the impregnation is followed by drying and the impregnation-drying step is repeated until the material has not gained weight.

8. Material according to any one of claims 1 to 7,

the number of layers n of the inorganic fiber thin-layer material is as follows: n is more than or equal to 2 and less than or equal to 10.

9. A method for preparing the aerogel thermal protection material with high-efficiency thermal insulation sandwich structure as claimed in any one of claims 1 to 8, which comprises the following steps:

(1) preparing a multilayer functional gradient thin felt: laying an inorganic fiber thin layer material and an infrared reflection film material according to the design requirement, and then compounding the laid materials into an integral structure through Z-direction needling to obtain the multilayer functionally graded thin felt;

(2) compounding the aerogel: dipping the multilayer functionally graded thin felt into an aerogel precursor to obtain the aerogel composite material matrix;

(3) fixing the inorganic fiber braided fabric: laying inorganic fiber braided fabrics on the upper surface and the lower surface of the aerogel composite material matrix, and sewing and fixing;

(4) forming the surface ceramic panel: and (4) soaking the material prepared in the step (3) in a ceramic precursor, and performing high-temperature treatment after soaking to obtain the high-efficiency heat-insulation sandwich structure aerogel heat-proof material.

10. The production method according to claim 9,

in the step (3), any one or more of alumina fiber, mullite fiber and quartz fiber is adopted for sewing; and/or

In the step (4), the high-temperature treatment is carried out under the oxygen-free condition, and the temperature is 500-800 ℃.

Technical Field

The invention relates to the technical field of thermal protection materials, in particular to an efficient thermal insulation sandwich structure aerogel heat-proof material and a preparation method thereof.

Background

For thermal protection materials used in the aerospace field, heat transfer occurs in three ways: solid phase conduction heat transfer, convection heat transfer, and radiation heat transfer. In the low temperature stage, the heat exchange is mainly solid phase and convection heat transfer, and in the high temperature stage (the temperature is more than or equal to 400 ℃), the radiation heat transfer is dominant. The temperature inside the thermal protection material is in gradient distribution along the thickness direction, so that high-efficiency thermal insulation is difficult to realize by adopting uniformly distributed thermal insulation materials. For example, for a thermal protection material having good thermal insulation and heat protection properties in an environment of 800 ℃, the thermal insulation and heat protection properties in an environment of 400 ℃ are not necessarily good. Therefore, the heat insulation performance of the heat protection material has great potential to be improved.

The aerospace ceramic tile is a main scheme for large-area thermal protection of the American space shuttle, is formed by sintering high-temperature resistant ceramic fibers at high temperature, and has higher technical maturity. However, the material has the defects of high brittleness, poor deformability, complex assembly, long period, high maintenance cost and the like, and the special forming process is difficult to realize the preparation of the functionally gradient structure distribution heat insulation material and meet the heat protection requirement of the future high-sound-speed aircraft.

Disclosure of Invention

An object of the present invention is to provide an aerogel thermal protection material having a highly efficient heat insulating sandwich structure.

The invention also aims to provide a preparation method of the aerogel heat-proof material with the efficient heat-insulating sandwich structure.

In order to achieve the purpose, the invention provides the following technical scheme:

an efficient thermal insulating sandwich structure aerogel thermal protection material, comprising:

aerogel composite matrix: the aerogel composite material matrix comprises a plurality of layers of functionally graded mats and aerogels dispersed in the inner parts and/or the surface layers of the plurality of layers of functionally graded mats; the multilayer functionally graded thin felt comprises a plurality of layers of inorganic fiber thin layers, infrared reflection film materials are clamped between the layers, the layers are compounded into an integral structure through Z-direction needling, the number of the inorganic fiber thin layers is n, the number of the infrared reflection film materials is n-1, and n is more than or equal to 2;

inorganic fiber woven fabric: the aerogel composite material matrix is paved on the upper surface and the lower surface of the aerogel composite material matrix and is fixed with the aerogel composite material matrix through sewing;

surface ceramic panel: is formed by impregnating a ceramic precursor with the aerogel composite matrix to which the inorganic fiber woven fabric is fixed.

Preferably, the inorganic fiber thin layer material is a material in the form of fiber felt, preferably one or more of zirconia fiber felt, alumina fiber felt, mullite fiber felt, quartz fiber felt, alumina silicate fiber felt, high silica fiber felt, basalt rock wool fiber felt and glass fiber felt;

further preferably, the thickness of the fiber felt is 1-10 mm;

further preferably, the fiber mat has a density of 0.05 to 0.25g/cm³Most preferably 0.10 to 0.15g/cm³。

Preferably, the infrared reflection film material is any one or more of aluminum foil, silicon carbide fiber cloth, carbon fiber cloth and silicon nitride fiber cloth.

Preferably, the aerogel is SiO₂Aerogel, Al₂O₃Aerogel, ZrO₂In aerogels, ceramic aerogelsAny one or more of; optionally, the aerogel is obtained by sol-gel, supercritical drying the multilayer functionally graded mat with an aerogel precursor; further preferably, the mass concentration of the aerogel precursor is 5-40%, most preferably 15-25%.

Preferably, the needling density of the Z-direction needling is 5-50 needles/cm²More preferably 20 to 40 needles/cm²。

Preferably, the inorganic fiber braided fabric is any one or more of alumina fiber cloth, mullite fiber cloth and quartz fiber cloth; optionally, the structure of the inorganic fiber braided fabric is plain cloth or satin cloth;

further preferably, the thickness of the woven inorganic fiber fabric laid on the upper surface of the aerogel composite substrate is 0.5 to 3mm, and the thickness of the woven inorganic fiber fabric laid on the lower surface of the aerogel composite substrate is 0.1 to 1 mm.

Preferably, the ceramic precursor is SiO₂Precursor and Al₂O₃Precursor, ZrO₂Any one or more of the precursors;

preferably, the impregnation is followed by drying and the impregnation-drying step is repeated until the material has not gained weight.

Preferably, the number of layers n of the inorganic fiber thin-layer material is as follows: n is more than or equal to 2 and less than or equal to 10.

A preparation method of the efficient heat insulation sandwich structure aerogel heat protection material comprises the following steps:

(1) preparing a multilayer functional gradient thin felt: laying an inorganic fiber thin layer material and an infrared reflection film material according to the design requirement, and then compounding the laid materials into an integral structure through Z-direction needling to obtain the multilayer functionally graded thin felt;

(2) compounding the aerogel: dipping the multilayer functionally graded thin felt into an aerogel precursor to obtain the aerogel composite material matrix;

(3) fixing the inorganic fiber braided fabric: laying inorganic fiber braided fabrics on the upper surface and the lower surface of the aerogel composite material matrix, and sewing and fixing;

(4) forming the surface ceramic panel: and (4) soaking the material prepared in the step (3) in a ceramic precursor, and performing high-temperature treatment after soaking to obtain the high-efficiency heat-insulation sandwich structure aerogel heat-proof material.

Preferably, in the step (3), sewing is performed by using any one or more of alumina fiber, mullite fiber and quartz fiber; and/or

In the step (4), the high-temperature treatment is carried out under the oxygen-free condition, and the temperature is 500-800 ℃.

Advantageous effects

The technical scheme of the invention has the following advantages:

the high-efficiency heat-insulation sandwich structure aerogel heat-insulation material provided by the invention has excellent heat-insulation performance: through carrying out structural design to the aerogel combined material base member, the aerogel combined material base member of design constitutes the sandwich layer of heat-proof material to multilayer structure is compound aerogel again as the carrier, gives the excellent heat-proof quality of heat-proof material. The detection shows that the room temperature thermal conductivity of the aerogel composite material matrix is 0.020-0.03W/m.K, and the room temperature thermal conductivity of the heat-proof material (taking the aerogel composite material matrix as a core layer) is 0.028-0.039W/m.K, which is superior to that of the aerospace heat-insulating tile.

The high-efficiency heat-insulation sandwich structure aerogel heat-proof material provided by the invention also has excellent scour resistance: on one hand, the invention strengthens the interlayer structural strength of the matrix (the effect is realized by Z-direction needling), and lays a good substrate; on the other hand, the ceramic panel is formed on the surface layer of the aerogel composite material matrix, so that the heat insulation performance of the heat-proof material is further improved, the mechanical strength of the heat-proof material is higher and is obviously higher than that of an aerospace heat insulation tile, and the scouring resistance of the panel is tens of times that of the aerospace heat insulation tile. The internal and external dual strengthening function enables the heat-proof material to bear high airflow scouring, and compared with the condition that other heat-proof materials can only be applied to the internal heat insulation of an aircraft, the heat-proof material provided by the invention can also be applied to the field of external heat insulation.

The efficient heat-insulating sandwich structure aerogel heat-proof material provided by the invention has good designability, can optimally design a plurality of layers of functionally graded mats according to the requirements of use temperature and heat-insulating property, and can realize the design of heat-proof materials with different heat-insulating properties by changing the types and the layers of fiber mats and/or infrared reflection film materials in the mats.

The high-efficiency heat-insulation sandwich structure aerogel heat-proof material can be used for designing larger-size components and even whole cabin partitions, reducing design pressure, simplifying complicated processes such as assembly, gap treatment and the like, and ensuring heat insulation effect.

According to the pneumatic thermal environment of different parts of the aircraft cabin, different heat-insulating felt materials are locally and specially configured, so that the aircraft cabin meets the requirements of complex application environments.

Drawings

FIG. 1 is a schematic flow diagram of a preparation method provided by the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

First aspect

The present invention provides, in a first aspect, a highly efficient thermal insulating sandwich structured aerogel thermal insulation material comprising an aerogel composite matrix, a woven inorganic fiber fabric, and a facer ceramic panel.

Aerogel composite matrix

The aerogel composite matrix comprises a plurality of layers of functionally graded mats and aerogels dispersed in the inner part and/or the surface layer of the plurality of layers of functionally graded mats.

Multilayer functionally graded mat: the multilayer function gradient thin felt comprises a plurality of layers of inorganic fiber thin layer materials, infrared reflection film materials are clamped between the layers, and the multilayer structure is compounded into an integral structure through Z-direction needling, namely the multilayer function gradient thin felt.

For inorganic fiber sheet materials: the inorganic fiber thin layer material is preferably a material in the form of fiber felt, such as one or more of zirconia fiber felt, alumina fiber felt, mullite fiber felt, quartz fiber felt, alumina silicate fiber felt, high silica fiber felt, basalt rock wool fiber felt and glass fiber felt. For the above-mentioned fiber mats, a suitable fiber mat can be selected depending on the temperature resistance range at the time of use. The temperature of the high-temperature zone is above 800 ℃, any one or more of zirconia fiber felt, alumina fiber felt, mullite fiber felt and quartz fiber felt can be selected, and the alumina fiber felt and the mullite fiber felt are preferred. The temperature of the medium temperature zone is less than 800 deg.C but below 600 deg.C, and can be selected from zirconia fiber felt, alumina fiber felt, mullite fiber felt, quartz fiber felt, aluminum silicate fiber felt, high silica fiber felt, and basalt rock wool fiber felt, preferably basalt rock wool fiber felt, aluminum silicate fiber felt, and high silica fiber felt. The low temperature zone is below 600 deg.C, and can be selected from zirconia fiber felt, alumina fiber felt, mullite fiber felt, quartz fiber felt, aluminum silicate fiber felt, high silica fiber felt, basalt rock wool fiber felt, and glass fiber felt, preferably basalt rock wool fiber felt, glass fiber felt, and high silica fiber felt. The multiple layers of fiber felts can be combined and layered according to different use temperatures, so that the heat insulation performance is optimized.

In addition to the type of fiber, the present invention also defines the density and thickness of the fiber mat. The thickness of the fiber mat is preferably 1-10mm, e.g., 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10 mm. The density of the fiber felt is preferably 0.05-0.25g/cm³Most preferably 0.10 to 0.15g/cm³。

For infrared reflective film materials: a layer of infrared reflection film material is sandwiched between two adjacent inorganic fiber thin-layer materials (such as fiber felts). The heat transfer of the heat insulating material generally comprises solid phase heat transfer, gas phase convection heat transfer and radiation heat transfer. The addition of the infrared reflection film material can reduce radiation heat transfer, thereby improving the heat insulation effect. The infrared reflection film material is preferably any one or more of aluminum foil, silicon carbide fiber cloth, carbon fiber cloth and silicon nitride fiber cloth. The material selection depends on the temperature area, the use temperature of the aluminum foil is generally not higher than 600 ℃, and the use temperature of the silicon nitride fiber cloth and the silicon carbide fiber cloth is not higher than 1000 ℃.

When preparing the multilayer functionally graded mat, the inorganic fiber thin layer material and the infrared reflection film material can be laid together according to the design, and then the bonding strength is improved through Z-direction needling. The Z-direction needling adopts a common needling process, and the needling density is preferably 5-50 needles/cm²Sufficient Z-direction bonding strength is provided, and the needling density is more preferably 20-40 needles/cm²。

The multiple layers in the multilayer functionally graded mat have the following meanings: the number of the inorganic fiber thin layer material is n, the number of the infrared reflection film material is n-1, n is more than or equal to 2, and more preferably, n is more than or equal to 2 and less than or equal to 10.

For aerogels dispersed within and/or on the surface of a multi-layer functionally graded mat: the aerogel is SiO₂Aerogel, Al₂O₃Aerogel, ZrO₂Any one or more of aerogels, ceramic aerogels. The aerogel can be obtained by carrying out sol-gel and supercritical drying on the multilayer functionally gradient thin felt and an aerogel precursor. Further preferably, the aerogel precursor concentration is 5-40%, most preferably 15-25%.

The heat-proof material matrix provided by the invention has good designability, can optimally design a multilayer function gradient thin felt according to the requirements of use temperature and heat-insulating property, and can realize the design of heat-proof materials with different heat-insulating properties by changing the types and the layer numbers of fiber felts and/or infrared reflection film materials in the thin felt.

According to the invention, through structural design of the aerogel composite material matrix, the designed aerogel composite material matrix forms the core layer of the heat-proof material, and the multilayer structure is taken as a carrier to be compounded with the aerogel, so that the heat-proof material is endowed with excellent heat-insulating property.

The invention also improves the anti-scouring performance of the heat-proof material through the following design, so that the heat-proof material can be applied to the fields of internal heat insulation and external heat insulation:

from the inside: the interlayer structure strength of the matrix is enhanced through Z-direction needling, and a good substrate is laid; from the outside, the ceramic panel is formed on the surface layer of the aerogel composite material matrix, so that the heat insulation performance of the heat-proof material is further improved, the mechanical strength of the heat-proof material is higher, the heat-proof material is obviously higher than that of an aerospace heat-insulation tile, and the scouring resistance of the panel is tens of times that of the aerospace heat-insulation tile. The inner and outer dual strengthening effect enables the heat-proof material to bear high airflow scouring.

Inorganic fiber braided fabric

The inorganic fiber braided fabric is laid on the upper surface and the lower surface of the aerogel composite material matrix and is fixed with the aerogel composite material matrix through sewing. The inorganic fiber braided fabric can improve the heat insulation performance of the surface layer of the heat-proof material, and the other important function is to serve as a ceramic panel framework to provide an inner core for the formation of the ceramic panel.

The inorganic fiber braided fabric is any one or more of alumina fiber cloth, mullite fiber cloth and quartz fiber cloth; optionally, the structure of the inorganic fiber woven fabric is plain cloth or satin cloth. Further preferably, the thickness of the woven inorganic fiber fabric laid on the upper surface of the aerogel composite substrate is 0.5 to 3mm, and the thickness of the woven inorganic fiber fabric laid on the lower surface of the aerogel composite substrate is 0.1 to 1 mm. Note that the heated surface is an upper surface.

Surface ceramic panel

The surface ceramic panel is formed by impregnating a ceramic precursor with an aerogel composite matrix to which an inorganic fiber woven fabric is fixed. More preferably, the impregnation is followed by drying, and the impregnation-drying step is repeated until the material does not gain weight.

The ceramic precursor is preferably SiO₂、Al₂O₃、ZrO₂Any one or more of.

The second aspect

The invention provides a preparation method of the high-efficiency heat-insulating sandwich structure aerogel heat-proof material provided by the first aspect in a second aspect. The preparation method comprises the following steps:

(1) preparing a multilayer functional gradient thin felt: laying an inorganic fiber thin layer material and an infrared reflection film material according to the design requirement, and then compounding the laid materials into an integral structure through Z-direction needling to obtain the multilayer functionally graded thin felt;

(2) compounding the aerogel: dipping the multilayer functionally graded thin felt into an aerogel precursor to obtain the aerogel composite material matrix;

(3) fixing the inorganic fiber braided fabric: laying inorganic fiber braided fabrics on the upper surface and the lower surface of the aerogel composite material matrix, and sewing and fixing; the stitching can be made of any one or more of alumina fiber, mullite fiber and quartz fiber.

(4) Forming the surface ceramic panel: and (4) soaking the material prepared in the step (3) in a ceramic precursor, and performing high-temperature treatment after soaking to obtain the high-efficiency heat-insulation sandwich structure aerogel heat-proof material. The high temperature treatment is preferably carried out under oxygen-free conditions at a temperature of 500-800 ℃.

The following are examples of the present invention.