Anti-ablation functional powder gradient composite material as well as preparation method and application thereof

Abstract

The invention relates to an anti-ablation functional powder gradient composite material as well as a preparation method and application thereof. The anti-ablation functional powder gradient composite material comprises a fiber woven framework, anti-ablation functional powder and ablation-resistant resin, the concentration of the anti-ablation functional powder in the composite material is distributed in a gradient descending manner from the surface to the inside along the normal direction of the ablation surface; based on 100 wt% of the total mass of the anti-ablation functional powder and the anti-ablation resin, the mass fraction of the anti-ablation functional powder is 2 wt%-20 wt%. According to the anti-ablation powder gradient composite material, the anti-ablation functional powder distributed in a gradient descending mode is constructed from the surface to the interior in the normal direction of the ablation face, the mechanical performance is guaranteed, and meanwhile the performance requirements of structural function integrated components such as ablation resistance, heat protection and high strength are met; the problems that a surface anti-ablation coating is prone to falling off, and the powder content affects the mechanical property of a composite material are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of fiber composite materials, and in particular to an anti-ablation functional powder gradient composite material and a preparation method and application thereof. Background Art

[0002] With the advancement of science and technology and the development of aerospace-related technologies, research on composite materials with integrated structural functions such as ablation resistance, heat protection, and high strength has become increasingly in-depth. Taking solid rocket engines as an example, they will generate huge acceleration during launch, and the engine nozzle needs to withstand external high-speed airflow erosion and high-temperature gas ablation at the same time, which puts forward the performance requirements of ablation resistance, heat protection, and high strength for composite materials used in nozzles.

[0003] In the past thirty years, resin-based composite materials have developed rapidly, and researchers have focused on improving the high-temperature resistance and ablation resistance of composite materials, while ensuring the load-bearing capacity of the composite material matrix. For example, CN114436679 discloses a heat-proof, heat-insulating, and load-bearing integrated lightweight carbon-ceramic composite material and its preparation method, which has a certain load-bearing effect while providing ultra-high thermal insulation. CN112538233 discloses a method for preparing a surface erosion-resistant low-density ablation heat-proof material, the upper layer of which is a continuous fiber fabric, and the lower layer is a gradient fiber preform of a low-density fiber mesh, which has a large coating amount and is easy to form an ablation-resistant surface layer. CN109910390 discloses a method for preparing a gradient density resin composite preform, in which the transition between each layer of material is uniform, eliminating interface problems, and improving the material's ablation resistance.

[0004] However, the average ignition point of resin-based composite materials is 400℃-480℃, which is difficult to meet the requirements of aerospace composite materials. However, the existing anti-ablation coating technology based on CVD, plasma spraying, etc. is easy to fall off under the action of high-speed airflow, and a large amount of metal oxide powder doped in the resin matrix will inevitably reduce the performance of the resin. Therefore, how to provide an anti-ablation material that remains stable in a high-temperature environment, has excellent anti-ablation performance and a simple preparation method has become a problem that needs to be solved urgently. Summary of the invention

[0005] In order to solve the above technical problems, the purpose of the present invention is to provide an anti-ablation functional powder gradient composite material and its preparation method and application. The present invention adds anti-ablation functional powder with a higher melting point into the composite material to greatly improve the high temperature resistance and anti-ablation performance of the composite material. The principle is that under the erosion and ablation of high-temperature gas, the anti-ablation functional powder plays a certain heat insulation effect, avoiding the internal carbon fiber from being ablated due to excessive temperature, and the anti-ablation functional powder itself has a higher melting point, so that the composite material remains stable in a high temperature environment.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] In the first aspect, the present invention provides an anti-ablation functional powder gradient composite material, which includes a fiber woven skeleton, anti-ablation functional powder and an ablation-resistant resin; the concentration of the anti-ablation functional powder in the composite material is distributed in a gradient decreasing manner from the surface to the inside along the normal direction of the ablation surface.

[0008] Taking the total mass of the anti-ablation functional powder and the ablation-resistant resin as 100wt%, the mass fraction of the anti-ablation functional powder is 2wt%-20wt%, for example, it can be 2wt%, 3wt%, 4wt%, 5wt%, 6wt%, 7wt%, 8wt%, 9wt%, 10wt%, 11wt%, 12wt%, 13wt%, 14wt%, 15wt%, 16wt%, 17wt%, 18wt%, 19wt% or 20wt%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0009] The present invention achieves a certain heat insulation effect by adding anti-ablation functional powder to the fiber woven skeleton. The anti-ablation functional powder itself has a relatively high melting point, which avoids ablation caused by excessively high internal fiber temperature, and keeps the composite material stable in a high temperature environment. On the one hand, the anti-ablation functional powder gradient composite material of the present invention can make full use of the high temperature resistance and ablation resistance of the ablation surface, while ensuring the bearing capacity of the non-ablation surface, and constructing a gradient descending distribution of anti-ablation functional powder from the surface to the inside along the normal direction of the ablation surface, meeting the performance requirements of structural functional integrated components such as anti-ablation, heat protection, and high strength, and solving the problems of easy detachment of the surface anti-ablation coating and the influence of the powder content on the mechanical properties of the composite material.

[0010] On the other hand, in order to ensure that a composite material with excellent high-temperature resistance and ablation resistance is obtained while ensuring that the mechanical properties of the material will not decrease significantly, and to ensure the stability of the comprehensive performance of the material during use, the mass fraction of the anti-ablation functional powder in the present invention is controlled to account for 2wt%-20wt% of the total mass of the anti-ablation functional powder and the ablation-resistant resin. The content of the ablation-resistant resin material seriously affects the tensile properties and bending strength of the material. If the mass fraction of the anti-ablation functional powder is too high, the mechanical properties of the composite material will decrease, the brittleness will be greater, and it will be not conducive to the use of the composite material.

[0011] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. Through the following preferred technical solutions, the technical objectives and beneficial effects of the present invention can be better achieved and realized.

[0012] Preferably, the anti-ablation functional powder includes any one of ZrO2, CeO2, Al2O3, SiO2, SiC, montmorillonite, carbon nanotubes or graphene, or a combination of at least two of them. Typical but non-limiting combinations include a combination of ZrO2 and CeO2, a combination of CeO2 and Al2O3, a combination of ZrO2, CeO2 and Al2O3, a combination of Al2O3, SiO2 and SiC, a combination of montmorillonite and graphene, a combination of montmorillonite, carbon nanotubes and graphene, a combination of ZrO2, carbon nanotubes and graphene, preferably ZrO2.

[0013] The anti-ablation functional powder used in the present invention has a high melting point and does not decompose at a temperature that meets the use scenario. It is converted into a grid skeleton structure through melting or in-situ sintering at high temperature, isolating the oxygen-containing atmosphere and maintaining the density of the composite material, thereby improving the anti-ablation performance of the composite material. Compared with other anti-ablation powders, such as ZrC, ZrB2, etc., the cost of raw materials is lower, and the mechanical properties of the anti-ablation functional powder gradient composite material are less affected. It can be introduced into the anti-ablation functional powder gradient composite material using a simple preparation process, and the process requirements are lower.

[0014] The total mass of the anti-ablation functional powder and the ablation-resistant resin accounts for 30wt%-45wt% of the mass fraction of the anti-ablation functional powder gradient composite material, for example, it can be 30wt%, 33wt%, 36wt%, 39wt%, 40wt%, 42wt%, 43wt%, or 45wt%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0015] In the present invention, the total mass fraction of the anti-ablation functional powder and the ablation-resistant resin in the anti-ablation functional powder gradient composite material is further controlled to be 30wt%-45wt%. Within this content range, the composite material has good ablation resistance and mechanical properties, and the comprehensive performance of the composite material is more excellent. If the total mass fraction of the anti-ablation functional powder and the ablation-resistant resin is too high, it will lead to poor fiber performance and an increase in the mass ablation rate of the composite material; if the total mass fraction of the anti-ablation functional powder and the ablation-resistant resin is too low, it will lead to poor tensile strength of the composite material.

[0016] Preferably, the median particle size of the anti-ablation functional powder is 50nm-2μm, for example, it can be 50nm, 100nm, 200nm, 300nm, 400nm, 500nm, 600nm, 700nm, 800nm, 900nm, 1μm, 1.1μm, 1.2μm, 1.3μm, 1.4μm, 1.5μm, 1.6μm, 1.7μm, 1.8μm, 1.9μm or 2μm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0017] Preferably, the fiber woven skeleton comprises any one of carbon fiber, high silica fiber, quartz fiber or aramid fiber, or a combination of at least two thereof. Typical but non-limiting combinations include a combination of carbon fiber and high silica fiber, a combination of quartz fiber and aramid fiber, a combination of high silica fiber and quartz fiber, a combination of carbon fiber and quartz fiber, a combination of carbon fiber, high silica fiber and aramid fiber, and a combination of carbon fiber, high silica fiber, quartz fiber and aramid fiber.

[0018] In the present invention, "high silica fiber" refers to high-purity quartz fiber with a SiO2 content of more than 96%; "quartz fiber" refers to high-purity quartz fiber with a SiO2 content of more than 99.95%.

[0019] Preferably, the model of the carbon fiber includes any one of T300, T700, T800 or T1000, or a combination of at least two thereof. Typical but non-limiting combinations include a combination of T300 and T700, a combination of T800 and T1000, a combination of T300 and T800, a combination of T300, T700 and T800, a combination of T300, T700 and T1000, and a combination of T300, T700, T800 and T1000.

[0020] Preferably, the weaving method of the fiber woven skeleton includes any one of three-dimensional weaving, weaving, plying / needling or Z-direction yarn composite or a combination of at least two. Typical but non-limiting combinations include a combination of three-dimensional weaving and weaving, a combination of plying / needling and Z-direction yarn composite, a combination of three-dimensional weaving, plying / needling and Z-direction yarn composite, a combination of three-dimensional weaving, weaving and Z-direction yarn composite, and a combination of three-dimensional weaving, weaving, plying / needling and Z-direction yarn composite.

[0021] Preferably, the ablation-resistant resin comprises a resin material with a carbon residue rate greater than 60%.

[0022] The ablation-resistant resin used in the present invention is more preferably a resin material with a residual carbon rate greater than 60%. The resin material with a high residual carbon rate still maintains density after being subjected to high temperature, and can also provide certain strength and heat-resistant protection for the fiber woven skeleton after carbonization.

[0023] Preferably, the ablation-resistant resin comprises any one of phenolic resin, polyimide resin or cyanate ester or a combination of at least two thereof. Typical but non-limiting combinations include a combination of phenolic resin and polyimide resin, a combination of polyimide resin and cyanate ester, a combination of phenolic resin and cyanate ester, and a combination of phenolic resin, polyimide resin and cyanate ester.

[0024] In a second aspect, the present invention provides a method for preparing the anti-ablation functional powder gradient composite material as described in the first aspect, the preparation method comprising the following steps:

[0025] The anti-ablation functional powder, the ablation-resistant resin and the solvent are mixed to obtain the modified resin, and the modified resin is infiltrated into the fiber woven skeleton by pressure assistance to obtain the anti-ablation functional powder gradient composite material.

[0026] The preparation method provided by the present invention uses a pressure-assisted infiltration method to introduce the modified resin into the fiber woven skeleton. Existing anti-ablation coating technologies mainly based on CVD, plasma spraying, etc. are easy to fall off under the action of high-speed airflow, and a large amount of metal oxide powder doped in the resin matrix will inevitably reduce the resin performance. The pressure-assisted infiltration method used in the present invention naturally forms a powder distribution gradient with the help of the skeleton fiber's interception function of the powder, and can prepare a material with an anti-ablation functional powder gradient composite, which greatly reduces the process difficulty and cost, requires less time, and has lower equipment requirements.

[0027] Preferably, the solvent comprises any one of ethanol, ethylene glycol, propanol or dimethylacetamide or a combination of at least two thereof, and typical but non-limiting combinations include a combination of ethanol and ethylene glycol, a combination of ethanol and propanol, and a combination of ethanol, ethylene glycol and propanol.

[0028] Preferably, the mixing method includes stirring and heat treatment.

[0029] Preferably, the stirring time is 1 h-12 h, for example, 1 h, 2 h, 3 h, 4 h, 5 h, 6 h, 7 h, 8 h, 9 h, 10 h, 11 h or 12 h, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0030] In the present invention, the stirring time is controlled to be 1h-12h, and stirring is performed in the mixing stage to promote uniform mixing between the anti-ablation functional powder material and the ablation-resistant resin, thereby maintaining the gradient change of the components in the subsequent infiltration process and improving the ablation resistance of the material.

[0031] Preferably, the temperature of the heat treatment is 50°C-100°C, for example, it can be 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C or 100°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0032] Preferably, the heat treatment time is 1h-12h, for example, it can be 1h, 2h, 3h, 4h, 5h, 6h, 7h, 8h, 9h, 10h, 11h or 12h, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0033] Preferably, the pressure-assisted infiltration method comprises vacuum filtration and / or high-pressure injection.

[0034] Preferably, the gauge pressure of the pressure-assisted osmosis is -0.09 MPa to 5 MPa, for example, it can be -0.09 MPa, -0.01 MPa, 0.1 MPa, 1 MPa, 1.5 MPa, 2 MPa, 2.5 MPa, 3 MPa, 3.5 MPa, 4 MPa, 4.5 MPa or 5 MPa, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0035] Preferably, the modified resin is subjected to pressure-assisted penetration into the fiber woven skeleton and then a curing treatment is performed.

[0036] Preferably, the curing method includes hot molding.

[0037] Preferably, the curing pressure of the hot molding method is 5 MPa-25 MPa, for example, it can be 5 MPa, 6 MPa, 7 MPa, 8 MPa, 9 MPa, 10 MPa, 11 MPa, 12 MPa, 13 MPa, 14 MPa, 15 MPa, 16 MPa, 17 MPa, 18 MPa, 19 MPa, 20 MPa, 21 MPa, 22 MPa, 23 MPa, 24 MPa or 25 MPa, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0038] Preferably, the curing temperature of the hot molding method is 150°C-360°C, for example, it can be 150°C, 180°C, 200°C, 220°C, 240°C, 260°C, 280°C, 300°C, 320°C, 340°C, 350°C or 360°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0039] Preferably, the curing time of the hot molding method is 1h-12h, for example, it can be 1h, 2h, 3h, 4h, 5h, 6h, 7h, 8h, 9h, 10h, 11h or 12h, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0040] As a preferred technical solution of the preparation method of the present invention, the preparation method comprises the following steps:

[0041] (1) mixing an anti-ablation functional powder and an ablation-resistant resin according to a mass ratio, adding a solvent and stirring, and heat treating at 50° C. to 100° C. for 1 h to 12 h to obtain a modified resin;

[0042] (2) stacking the fiber braided skeleton into a mold, spreading 10 to 50 layers, pouring the modified resin into the mold, and using vacuum filtration under a gauge pressure of -0.09 MPa to 2 MPa to allow the modified resin to penetrate into the fiber braided skeleton;

[0043] (3) placing the mold in a flat vulcanizer, curing it for 1h-12h by hot pressing under the conditions of a pressure of 5MPa-25Mpa and a temperature of 150°C-360°C, and demolding after the curing is completed to obtain an anti-ablation functional powder gradient composite material.

[0044] In a third aspect, the present invention provides an application of the anti-ablation functional powder gradient composite material as described in the first aspect, wherein the anti-ablation functional powder gradient composite material is used in the field of aerospace structural materials.

[0045] The anti-ablation functional powder gradient composite material provided by the present invention has excellent anti-ablation performance and excellent mechanical properties. It can meet the performance requirements of high-temperature structural parts such as engine nozzles, air inlets, combustion chambers, etc. in the aerospace field. It has lower cost and broad application prospects.

[0046] The numerical range described in the present invention not only includes the point values ​​listed above, but also includes any point values ​​between the above numerical ranges that are not listed. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0047] Compared with the prior art, the present invention has at least the following beneficial effects:

[0048] (1) The anti-ablation powder gradient composite material provided by the present invention constructs an anti-ablation functional powder with a gradient distribution from the surface to the inside along the normal direction of the ablation surface. While ensuring the mechanical properties, it meets the performance requirements of structural functional integrated components such as anti-ablation, heat protection, and high strength, and solves the problems of easy detachment of the surface anti-ablation coating and the influence of the powder content on the mechanical properties of the composite material.

[0049] (2) The pressure-assisted infiltration method adopted in the present invention can prepare a material with anti-ablation functional powder gradient composite by taking advantage of the pressure difference naturally formed by the thickness of the material, which greatly reduces the process difficulty and cost, shortens the time required, and reduces the equipment requirements.

[0050] (3) The anti-ablation functional powder gradient composite material provided by the present invention has excellent anti-ablation performance and excellent mechanical properties, which can meet the use requirements of aerospace structural materials, has lower cost and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 is a 3D schematic diagram of a fiber braided skeleton before hot pressing in Example 1 of the present invention;

[0052] Figure 2 This is a cross-sectional view of the composite material prepared in Example 1 of the present invention;

[0053] Figure 3 A top view of the composite material prepared in Example 1 of the present invention;

[0054] Figure 4 This is a scanning electron microscope image of the composite material prepared in Example 1 of the present invention after ablation;

[0055] Figure 5 This is a scanning electron microscope image of the composite material prepared in Comparative Example 1 of the present invention after ablation. DETAILED DESCRIPTION

[0056] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and through specific implementation methods. However, the following examples are only simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims.

[0057] In the following examples and comparative examples, unless otherwise specified, all reagents and consumables were purchased from conventional reagent manufacturers in the field; unless otherwise specified, the experimental methods and technical means used were conventional methods and means in the field.

[0058] Example 1

[0059] This embodiment provides an anti-ablation functional powder gradient composite material, the anti-ablation functional powder gradient composite material includes a fiber woven skeleton (structure such as Figure 1 As shown), anti-ablation functional powder and ablation-resistant resin; the concentration of the anti-ablation functional powder in the composite material is distributed in a gradient downward from the surface to the inside along the normal direction of the ablation surface (as shown Figure 2 As shown); the anti-ablation functional powder and the ablation-resistant resin account for 36% of the anti-ablation functional powder gradient composite material, and the mass fraction of the anti-ablation functional powder and the ablation-resistant resin is 5wt% based on the total mass of the anti-ablation functional powder and the ablation-resistant resin as 100wt%;

[0060] The method for preparing the anti-ablation functional powder gradient composite material provided in this embodiment comprises the following steps:

[0061] (1) ZrO2 with a median particle size of 100 nm, phenolic resin (PF206) and 200 mL of ethanol were mixed according to the mass ratio, stirred for 6 h, and heat treated at 80 ° C for 6 h to obtain a modified resin;

[0062] (2) Stack carbon fiber cloth (T700-12K, Toray) and place it in a mold, spread 20 layers, pour the modified resin into the mold, and under a gauge pressure of -0.09 MPa, vacuum filter the modified resin to penetrate into the carbon fiber cloth until the prepreg is completely filtered;

[0063] (3) The mold was placed in a flat-plate vulcanizer and cured for 6 h using a hot molding method under a pressure of 10 MPa and a temperature of 170°C. After curing, the mold was demolded to obtain an anti-ablation functional powder gradient composite material.

[0064] 3D schematic diagram of fiber woven skeleton Figure 1 As shown, from Figure 1 It can be seen that carbon fiber cloth is mainly laid in layers and prepared by z-axis stitching.

[0065] The cross-sectional view of the prepared anti-ablation functional powder gradient composite material is shown in Figure 2 As shown, from Figure 2 It can be seen that the content of anti-ablation functional powder gradually decreases from the upper surface to the bottom.

[0066] The top view of the prepared anti-ablation functional powder gradient composite material is shown in Figure 3 As shown, from Figure 3 It can be seen that the functional powder is evenly distributed without obvious powder aggregation.

[0067] The scanning electron microscope image of the prepared anti-ablation functional powder gradient composite material after ablation is shown in Figure 4 As shown, from Figure 4 It can be seen that after ablation, the surface of the composite material is relatively intact, and metal oxide particles appear, which is beneficial to improving the anti-ablation performance of the composite material. Therefore, the mass ablation rate of the composite material in Example 1 is relatively low.

[0068] Example 2

[0069] The present embodiment provides an anti-ablation functional powder gradient composite material, the anti-ablation functional powder gradient composite material comprises a fiber woven skeleton, an anti-ablation functional powder and an ablation-resistant resin; the concentration of the anti-ablation functional powder in the composite material is distributed in a gradient decreasing manner from the surface to the inside along the normal direction of the ablation surface; the anti-ablation functional powder and the ablation-resistant resin account for 33% of the anti-ablation functional powder gradient composite material, and the mass fraction of the anti-ablation functional powder is 20wt% based on the total mass of the anti-ablation functional powder and the ablation-resistant resin as 100wt%;

[0070] The method for preparing the anti-ablation functional powder gradient composite material provided in this embodiment comprises the following steps:

[0071] (1) ZrO2 with a median particle size of 500 nm, phenolic resin and 500 mL of ethanol were mixed according to the mass ratio, stirred for 6 h, and heat treated at 90° C. for 5 h to obtain a modified resin;

[0072] (2) Stack the carbon fiber cloth into the mold, spread 20 layers, pour the modified resin into the mold, and under the condition of -0.09 MPa, vacuum filter the modified resin into the carbon fiber cloth until the prepreg is completely filtered;

[0073] (3) The mold is placed in a flat vulcanizer and cured for 8 hours using a hot molding method under a pressure of 15 MPa and a temperature of 300°C. After curing, the mold is demolded to obtain an anti-ablation functional powder gradient composite material.

[0074] Example 3

[0075] The present embodiment provides an anti-ablation functional powder gradient composite material, the anti-ablation functional powder gradient composite material comprises a fiber woven skeleton, an anti-ablation functional powder and an ablation-resistant resin; the concentration of the anti-ablation functional powder in the composite material is distributed in a gradient downward distribution from the surface to the inside along the normal direction of the ablation surface; the anti-ablation functional powder and the ablation-resistant resin account for 42% of the anti-ablation functional powder gradient composite material, and the mass fraction of the anti-ablation functional powder is 2wt% based on the total mass of the anti-ablation functional powder and the ablation-resistant resin as 100wt%;

[0076] The method for preparing the anti-ablation functional powder gradient composite material provided in this embodiment comprises the following steps:

[0077] (1) ZrO2 with a median particle size of 50 nm, polyimide resin (PMDA-ODA) and 100 mL of dimethylacetamide were mixed according to the mass ratio, stirred for 4 h, and heat treated at 60 ° C for 12 h to obtain a modified resin;

[0078] (2) stacking carbon fiber cloth into a mold, spreading 20 layers, pouring modified resin into the mold, and vacuum filtering under a gauge pressure of 1 MPa to allow the modified resin to penetrate into the carbon fiber cloth, and filtering until the prepreg is completely filtered;

[0079] (3) The mold is placed in a flat-plate vulcanizer and cured for 12 h using a hot molding method under a pressure of 5 MPa and a temperature of 150°C. After the curing is completed, the mold is demolded to obtain an anti-ablation functional powder gradient composite material.

[0080] Example 4

[0081] This embodiment provides an anti-ablation functional powder gradient composite material. The only difference from Example 1 is that when preparing the anti-ablation functional powder gradient composite material, the carbon fiber cloth in step (2) is replaced by a carbon fiber prewoven body (Beijing Jike Guochuang Lightweight Science Research Institute Co., Ltd.), and the other parameters and steps are the same as those in Example 1.

[0082] Example 5

[0083] This embodiment provides an anti-ablation functional powder gradient composite material. The only difference from Example 1 is that when preparing the anti-ablation functional powder gradient composite material, ZrO2 in step (1) is replaced with an equal mass of CeO2, and the other parameters and steps are the same as those in Example 1.

[0084] Example 6

[0085] This embodiment provides an anti-ablation functional powder gradient composite material, which is different from Example 1 only in that the total mass of the anti-ablation functional powder and the ablation-resistant resin accounts for 25wt% of the mass fraction of the anti-ablation functional powder gradient composite material, and other parameters and steps are the same as those in Example 1.

[0086] Example 7

[0087] This embodiment provides an anti-ablation functional powder gradient composite material, which is different from Example 1 only in that the total mass of the anti-ablation functional powder and the ablation-resistant resin accounts for 55wt% of the mass fraction of the anti-ablation functional powder gradient composite material, and other parameters and steps are the same as those in Example 1.

[0088] Example 8

[0089] This embodiment provides an anti-ablation functional powder gradient composite material, which is different from Embodiment 1 only in that, when preparing the anti-ablation functional powder gradient composite material, the phenolic resin in step (1) is replaced by epoxy resin (EP-44).

[0090] Comparative Example 1

[0091] This comparative example provides an anti-ablation functional powder gradient composite material, which differs from Example 1 only in that, when preparing the anti-ablation functional powder gradient composite material, the total mass of the anti-ablation functional powder and the ablation-resistant resin in step (1) is taken as 100wt%, and the mass fraction of the anti-ablation functional powder is 1wt%, and the other parameters and steps are the same as those in Example 1.

[0092] Comparative Example 2

[0093] This comparative example provides an anti-ablation functional powder gradient composite material, which differs from Example 1 only in that, when preparing the anti-ablation functional powder gradient composite material, the total mass of the anti-ablation functional powder and the ablation-resistant resin in step (1) is taken as 100wt%, and the mass fraction of the anti-ablation functional powder is 30wt%. Other parameters and steps are the same as those in Example 1.

[0094] Comparative Example 3

[0095] This comparative example provides a composite material having a surface layer containing anti-ablation functional powder, and a method for preparing the anti-ablation functional powder gradient composite material comprises:

[0096] (1) Take 100 nm ZrO2 particles, add them into phenolic resin at a solid content of 5%, then add 200 mL ethanol, stir well for 6 h, and heat treat at 80 °C for 6 h to obtain modified resin;

[0097] (2) separately preparing phenolic resin, adding 200 mL of ethanol, stirring thoroughly for 6 h, and heat treating at 80° C. for 6 h to obtain a phenolic resin solution;

[0098] (3) stacking the carbon fiber cloth into a mold, spreading 19 layers, pouring the phenolic resin solution obtained in step (2) into the mold, and filtering until the prepreg is completely filtered to obtain a phenolic prepreg;

[0099] (4) taking the carbon fiber cloth and impregnating it into the modified resin prepared in step (1), taking it out, and preparing a ZrO2 prepreg cloth;

[0100] (5) spreading a layer of the ZrO2 prepreg prepared in step (4) onto the surface of the phenolic prepreg prepared in step (3);

[0101] (6) The mold is placed in a flat vulcanizer for pressurized curing at a curing pressure of 10 MPa, a curing temperature of 170° C., and a curing time of 6 h. After curing, the mold is removed to obtain a composite material containing anti-ablation functional powder on the surface layer.

[0102] The scanning electron microscope image of the prepared composite material after ablation is shown in Figure 5 As shown, from Figure 5 It can be seen that after ablation, many ablation pores appear on the surface of the composite material, which is not conducive to improving the anti-ablation performance of the composite material. This is also a manifestation of high mass ablation rate.

[0103] Comparative Example 4

[0104] This comparative example provides a composite material, which is different from Example 1 only in that ZrO2 is not added in step (1) when preparing the anti-ablation functional powder gradient composite material.

[0105] Test method: The ablation resistance of the composite materials prepared in the embodiments and comparative examples was tested: the zirconium oxide functional powder gradient composite materials finally obtained in each embodiment and comparative example were tested using a thermal protection material ablation experimental test platform. The relevant parameters are described in Table 1 below, and the test results are shown in Table 2 below.

[0106] Table 1

[0107]

[0108] Table 2

[0109]

[0110]

[0111] The test results show that:

[0112] (1) It can be seen from Examples 1 to 5 that the anti-ablation functional powder gradient composite material of the present invention can fully utilize the high temperature and ablation resistance of the ablation surface while ensuring the bearing capacity of the non-ablation surface, and construct an anti-ablation functional powder with a gradient distribution from the surface to the inside along the normal direction of the ablation surface, thereby meeting the performance requirements of structural functional integrated components such as ablation resistance, heat protection, and high strength.

[0113] (2) It can be seen from Example 1 and Example 6-Example 7 that the present invention further controls the mass fraction of the anti-ablation functional powder to account for 30wt%-45wt% of the total mass of the anti-ablation functional powder and the ablation-resistant resin. Within this content range, the composite material has good ablation resistance and mechanical properties, and the comprehensive performance of the composite material is more excellent. If the total mass fraction of the anti-ablation functional powder and the ablation-resistant resin is too high, it will lead to poor fiber performance and an increase in the mass ablation rate of the composite material; if the total mass fraction of the anti-ablation functional powder and the ablation-resistant resin is too low, it will lead to a decrease in tensile strength.

[0114] (3) By comparing Example 1 with Example 8, it can be seen that the ablation-resistant resin used in the present invention is preferably a resin material with a high carbon residue rate. After being subjected to high temperature, the resin material will not produce pores or turn into powder and fall off, and after carbonization, it can also play a certain heat-resistant protection role for the fiber woven skeleton. If a material with a low carbon residue is selected, the heat resistance of the composite material will be affected.

[0115] (4) It can be seen from Example 1 and Comparative Examples 1-2 that the present invention further controls the mass fraction of the anti-ablation functional powder to account for 2wt%-20wt% of the total mass of the anti-ablation functional powder and the ablation-resistant resin. The content of the ablation-resistant resin material seriously affects the tensile properties and bending strength of the material. If the mass fraction of the anti-ablation functional powder is too high, the mechanical properties of the composite material will decrease, the brittleness will be greater, and it will be not conducive to the use of the composite material.

[0116] (5) It can be seen from Example 1 and Comparative Example 3 that the anti-ablation functional powder gradient composite material of the present invention can make full use of the high temperature and ablation resistance of the ablation surface, while ensuring the bearing capacity of the non-ablation surface, and construct an anti-ablation functional powder with a gradient distribution from the surface to the inside along the normal direction of the ablation surface, so as to meet the performance requirements of structural functional integrated components such as ablation resistance, heat protection, and high strength. If the anti-ablation functional powder is contained only in a layer on the surface, the inner layer of the composite material that is also subjected to high temperature ablation will not have the characteristics of heat resistance and ablation resistance, thereby affecting the overall effect of the material.

[0117] (6) It can be seen from Example 1 and Comparative Example 4 that the present invention achieves a certain thermal insulation effect by adding anti-ablation functional powder to the fiber woven skeleton. The anti-ablation functional powder itself has a relatively high melting point, which avoids ablation caused by excessively high internal fiber temperature, thereby keeping the composite material stable in a high temperature environment. When the anti-ablation functional powder is not added, its anti-ablation performance is greatly reduced.

[0118] In summary, the present invention achieves a certain heat insulation effect by adding anti-ablation functional powder to the fiber woven skeleton. The anti-ablation functional powder itself has a relatively high melting point, which avoids ablation caused by excessively high internal fiber temperature, and keeps the composite material stable in a high temperature environment. The anti-ablation functional powder gradient composite material of the present invention can make full use of the high temperature and ablation resistance of the ablation surface, while ensuring the bearing capacity of the non-ablation surface, and constructs a gradient descending distribution of anti-ablation functional powder from the surface to the inside along the normal direction of the ablation surface, meeting the performance requirements of structural functional integrated components such as anti-ablation, heat protection, and high strength, and solving the problems of easy detachment of the surface anti-ablation coating and the influence of the powder content on the mechanical properties of the composite material.

[0119] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. An anti-ablation functional powder gradient composite material, characterized in that: The anti-ablation functional powder gradient composite material comprises a fiber woven skeleton, anti-ablation functional powder and ablation-resistant resin; the concentration of the anti-ablation functional powder in the composite material is distributed in a gradient decreasing manner from the surface to the inside along the normal direction of the ablation surface; Based on the total mass of the anti-ablation functional powder and the ablation-resistant resin being 100wt%, the mass fraction of the anti-ablation functional powder is 2wt%-20wt%.

2. The anti-ablation functional powder gradient composite material according to claim 1, characterized in that: The anti-ablation functional powder includes any one of ZrO2, CeO2, Al2O3, SiO2, SiC, montmorillonite, carbon nanotubes or graphene, or a combination of at least two thereof; Preferably, the total mass of the anti-ablation functional powder and the ablation resistant resin accounts for 30wt%-45wt% of the mass fraction of the anti-ablation functional powder gradient composite material.

3. The anti-ablation functional powder gradient composite material according to claim 1 or 2, characterized in that: The median particle size of the anti-ablation functional powder is 50nm-2μm.

4. The anti-ablation functional powder gradient composite material according to any one of claims 1 to 3, characterized in that: The fiber braided skeleton includes any one of carbon fiber, high silica fiber, quartz fiber or aramid fiber, or a combination of at least two thereof; Preferably, the carbon fiber type includes any one of T300, T700, T800 or T1000, or a combination of at least two of them; Preferably, the braiding method of the fiber braided skeleton includes any one of three-dimensional braiding, weaving, plying / needling or Z-direction yarn composite, or a combination of at least two thereof.

5. The anti-ablation functional powder gradient composite material according to any one of claims 1 to 4, characterized in that: The ablation-resistant resin includes a resin material having a carbon residue rate greater than 60%; Preferably, the ablation-resistant resin includes any one of phenolic resin, polyimide resin or cyanate ester, or a combination of at least two of them.

6. A method for preparing the anti-ablation functional powder gradient composite material according to any one of claims 1 to 5, characterized in that: The preparation method comprises the following steps: The anti-ablation functional powder, the ablation-resistant resin and the solvent are mixed to obtain the modified resin, and the modified resin is infiltrated into the fiber woven skeleton by pressure assistance to obtain the anti-ablation functional powder gradient composite material.

7. The preparation method according to claim 6, characterized in that: The solvent includes any one of ethanol, ethylene glycol, propanol or dimethylacetamide or a combination of at least two thereof; Preferably, the mixing method includes stirring and heat treatment; Preferably, the stirring time is 1h-12h; Preferably, the temperature of the heat treatment is 50°C-100°C; Preferably, the heat treatment time is 1h-12h.

8. The preparation method according to claim 6 or 7, characterized in that: The pressure-assisted infiltration method includes vacuum filtration and / or high-pressure injection; Preferably, the gauge pressure of the pressure-assisted osmosis is -0.09 MPa to 5 MPa.

9. The preparation method according to any one of claims 6 to 8, characterized in that: After the modified resin is pressure-assisted to penetrate into the fiber braided skeleton, a curing treatment is also performed; Preferably, the curing method includes hot molding; Preferably, the curing pressure of the hot molding method is 5MPa-25MPa; Preferably, the curing temperature of the hot molding method is 150°C-360°C; Preferably, the curing time of the hot molding method is 1h-12h.

10. An application of the anti-ablation functional powder gradient composite material according to any one of claims 1 to 5, characterized in that: The anti-ablation functional powder gradient composite material is used in the field of aerospace structural materials.

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