Functional ceramic phase-nanoporous resin ablative-resistant composite material and preparation method thereof

Abstract

The application relates to a functional ceramic phase-nanopore resin ablation-resistant composite material and a preparation method thereof, and belongs to the technical field of ceramic-based thermal protection materials. The preparation method comprises the following steps: mixing ablation-resistant ceramic powder, sintering-assisted ceramic powder and high-emissivity ceramic powder in proportion, and obtaining mixed powder after ball milling; adding the mixed powder into a dispersant to obtain ceramic slurry; applying the ceramic slurry on the upper surface of a fiber preform after roughening pretreatment of the fiber, and then promoting uniform penetration of the slurry into the fiber through auxiliary oscillation to obtain a fiber preform loaded with a functional ceramic phase; and placing the fiber preform in a mold, injecting resin sol into the mold through an RTM process, sealing the mold, and preparing the functional ceramic phase-nanopore resin ablation-resistant composite material through solidification and normal-pressure drying. The obtained composite material not only has low density and low thermal conductivity, but also has high ablation resistance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ceramic-based thermal protection materials, and particularly relates to a functional ceramic phase-nanoporous resin ablation-resistant composite material and a preparation method thereof. BACKGROUND

[0002] In the field of thermal protection technology of aerospace vehicles, the ablation resistance and thermal insulation performance of thermal protection materials directly determine the service life and safety performance of the vehicles.

[0003] At present, thermal protection materials mainly include resin-based thermal protection materials and ceramic-based composites. Although the resin-based thermal protection materials have advantages such as simple forming process and low density, they have significant limitations in high-temperature aerodynamic environments. Due to the insufficient thermal stability and oxidation resistance of the resin matrix, the material is prone to severe carbonization and decomposition during ablation at ultra-high temperatures (for example, at a temperature above 2000 DEG C), resulting in high mass loss rate of the heat protection layer and surface brittle spalling phenomenon, which is difficult to meet the extreme thermal protection requirements of high-Mach number and long-time flight missions.

[0004] While the ceramic-based composites exhibit excellent ablation resistance in short-time thermal shock conditions due to their high melting point, excellent high-temperature mechanical properties and chemical stability, the excessively high thermal conductivity makes them unable to effectively block heat transfer, and thus cannot meet the long-time thermal insulation requirements.

[0005] Therefore, there is an urgent need for a thermal protection material with low density and low thermal conductivity, and high ablation resistance, to meet the use in more severe environments or higher requirements. SUMMARY

[0006] In view of the above analysis, the present application aims to provide a functional ceramic phase-nanoporous resin ablation-resistant composite material and a preparation method thereof, which can greatly improve the ablation resistance while ensuring low density and low thermal conductivity.

[0007] In one aspect, the present application provides a preparation method of a functional ceramic phase-nanoporous resin ablation-resistant composite material, comprising the following steps:

[0008] S1: Preparation of ceramic slurry; mixing ablation-resistant ceramic powder, sintering-assisted ceramic powder and high-emissivity ceramic powder in proportion, obtaining mixed powder after ball milling; adding the mixed powder into a dispersant, and then adding a binder to obtain the ceramic slurry;

[0009] S2: Preparation of a fiber preform loaded with functional ceramic phases; performing fiber roughening pretreatment on the upper surface of the fiber preform, then applying the ceramic slurry on the upper surface of the fiber preform, and then obtaining the fiber preform loaded with functional ceramic phases through auxiliary oscillation;

[0010] S3: the fiber preform is placed in a mold, a resin sol is injected into the mold by using a RTM process, the resin sol is a hybrid phenolic resin sol, the mold is sealed, and a functional ceramic phase-nanoporous resin ablative-resistant composite material is prepared through solidification and normal pressure drying.

[0011] Further, the melting point of the ablative-resistant ceramic powder is higher than 2600℃.

[0012] Preferably, the ablative-resistant ceramic powder is selected from zirconium boride, silicon dioxide, silicon nitride, zirconium oxide, hafnium carbide and titanium carbide.

[0013] Further, the sintering-aid ceramic powder is selected from low-melting-point glass powder, titanium dioxide, yttrium oxide, lanthanum oxide and cerium oxide.

[0014] Further, the emissivity of the high-emissivity ceramic powder is higher than 0.85.

[0015] Preferably, the high-emissivity ceramic powder is selected from molybdenum silicide, chromium trioxide and silicon nitride.

[0016] Further, the mass ratio of the ablative-resistant ceramic powder, the sintering-aid ceramic powder and the high-emissivity ceramic powder is (6-8):(4-6):(3-4).

[0017] Further, in step S2, the fiber roughening pretreatment includes at least one of plasma etching treatment, sandblasting roughening treatment or silane coupling agent treatment.

[0018] Further, in step S2, the ceramic slurry is applied on the upper surface of the fiber preform by using a cyclic low-pressure cold spraying-drying process.

[0019] Further, in step S2, the fiber preform is selected from carbon fiber, quartz fiber, phenolic fiber, mullite fiber, polyacrylonitrile fiber and silicon carbide fiber.

[0020] The fiber preform structure is a needle-punched web, a laminated needle-punched fabric / web, 2.5D weaving, orthogonal three-way weaving or three-dimensional multi-way weaving structure.

[0021] Further, the resin sol is selected from hybrid phenolic resin sol.

[0022] In another aspect, the present application provides a functional ceramic phase-nanoporous resin ablative-resistant composite material, which is obtained by the preparation method of the present application.

[0023] Compared with the prior art, the present application can at least achieve one of the following beneficial effects:

[0024] 1、The functional ceramic phase-nanoporous resin ablative-resistant composite material is prepared by coating ceramic material on the fiber preform through cyclic low-pressure cold spraying-drying treatment, uniformly laying on the surface and penetrating into the inside, and finally injecting resin sol.

[0025] 2、The multiple cycle cold spraying-drying process adopted in the application can gradually densify the surface, thereby improving the ablative resistance of the material, and after high-temperature oxyacetylene ablation, the composite material has a smooth and increased hardness after ablation, which is beneficial to enhancing the mechanical properties of the material at high temperature.

[0026] The above technical solutions can be combined with each other in the application to achieve more preferred combination solutions. Other features and advantages of the application will be described in the subsequent specification, and some advantages will become apparent from the specification, or will be understood by implementing the application. The purposes and other advantages of the application can be achieved and obtained from the contents specifically indicated in the specification and the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0027] The accompanying drawings are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the principles of the application.

[0028] Figure 1 The morphology of the nanoporous resin-based composite material of Comparative Example 1;

[0029] Figure 2 The morphology of the functional ceramic phase-nanoporous resin ablative-resistant composite material of Example 3;

[0030] Figure 3 The morphology of the nanoporous resin-based composite material of Comparative Example 1 after ablation;

[0031] Figure 4 The morphology of the functional ceramic phase-nanoporous resin ablative-resistant composite material of Example 3 after ablation;

[0032] Figure 5 The surface profile lines of Comparative Example 1 and Example 3 after ablation. DETAILED DESCRIPTION

[0033] The preferred embodiments of the application will be specifically described below in combination with the drawings, wherein the drawings constitute a part of the application and are used together with the embodiments of the application to explain the principles of the application, but are not used to limit the scope of the application.

[0034] In the field of thermal protection technology of spacecraft, the ablative resistance and thermal insulation performance of thermal protection materials directly determine the service life and safety performance of the spacecraft.

[0035] Currently, the heat protection materials mainly have resin-based heat protection materials and ceramic matrix composites, the ceramic matrix composites have the characteristics of high melting point and excellent ablation resistance, but the density and thermal conductivity are also high, and the long-time heat insulation demand cannot be met. The resin-based composite material has low density and low thermal conductivity, and can achieve the purpose of weight reduction and high-efficiency heat insulation, but the ablation resistance is poor.

[0036] Therefore, the application provides a preparation method of a functional ceramic phase-nanopore resin ablation-resistant composite material, comprising the following steps:

[0037] S1: preparation of ceramic slurry; ablation-resistant ceramic powder, sintering aid ceramic powder and high-emissivity ceramic powder are mixed in proportion, and mixed powder is obtained after ball milling; the mixed powder is added to a dispersant, and a binder is further added to obtain the ceramic slurry;

[0038] S2: preparation of a fiber preform loaded with a functional ceramic phase; the upper surface of the fiber preform is subjected to fiber roughening pretreatment, the ceramic slurry is then applied to the upper surface of the fiber preform, and then an auxiliary oscillation is performed to obtain the fiber preform loaded with the functional ceramic phase;

[0039] S3: the fiber preform is placed in a mold, resin sol is injected into the mold by using an RTM process, the resin sol is a hybrid phenolic resin sol, the mold is sealed, and the functional ceramic phase-nanopore resin ablation-resistant composite material is prepared through solidification and normal-pressure drying.

[0040] Compared with the prior art, the ceramic material is coated on the fiber preform by using cyclic low-pressure cold spraying-drying treatment in the application, can be uniformly laid on the surface and penetrated into the inside, and finally the resin sol is injected to prepare the functional ceramic phase-nanopore resin interpenetrating network ablation-resistant composite material. The obtained composite material not only has low density and low thermal conductivity, but also has excellent ablation resistance.

[0041] In the application, the ceramic slurry is prepared by compounding ablation-resistant ceramic powder, sintering aid ceramic powder and high-emissivity ceramic powder, wherein the ablation-resistant ceramic powder provides the basic ablation resistance; then the sintering aid ceramic powder acts as a connecting agent to connect the ablation-resistant ceramic powder and the high-emissivity ceramic powder, and at the same time, the sintering aid ceramic powder improves the density and interface bonding capacity of the ablation-resistant ceramic powder and the high-emissivity ceramic powder, further enhancing the ablation resistance of the final composite material. The high-emissivity ceramic powder reduces the surface temperature by enhancing the thermal radiation capacity, further reducing the erosion of the heat flow on the composite material. The synergistic effect of the three makes the composite material better resist ablation in a high-temperature environment.

[0042] Specifically, the melting point of the ablation-resistant ceramic powder is higher than 2600℃.

[0043] Preferably, the ablation-resistant ceramic powder is selected from zirconium boride, silicon dioxide, silicon nitride, zirconium oxide, hafnium carbide and titanium carbide.

[0044] It should be noted that the ablation-resistant ceramic powder, as the main ablation-resistant material, is not easy to ablate and pyrolyze, thereby maintaining the shape integrity of the material. The present application requires the use of ablation-resistant ceramic powder with a melting point higher than 2600℃, such as zirconium boride, silicon dioxide, silicon nitride, zirconium oxide, hafnium carbide and titanium carbide, which can be combined with one or more of them.

[0045] Specifically, the sintering-aid ceramic powder is selected from low-melting-point glass powder, titanium dioxide, yttrium oxide, lanthanum oxide and cerium oxide.

[0046] It should be noted that the sintering-aid ceramic powder is used as an adhesive, which can better combine the ablation-resistant ceramic powder and the high-emissivity ceramic powder. The sintering-aid ceramic powder has a melting point < 800℃, which can quickly melt and form a liquid phase at a lower temperature. The presence of the liquid phase can significantly improve the sintering kinetics, promote the diffusion and rearrangement between the particles, thereby accelerating the sintering rate. At the same time, after the sintering-aid ceramic powder is melted, the liquid phase formed can fill the pores between the particles, reducing the porosity and thereby improving the density of the material.

[0047] Specifically, the high-emissivity ceramic powder has an emissivity higher than 0.85.

[0048] Preferably, the high-emissivity ceramic powder is selected from molybdenum silicide, chromium sesquioxide and silicon nitride.

[0049] It should be noted that the high-emissivity ceramic powder is used as high infrared radiation, which can quickly and efficiently radiate a large amount of heat in the form of infrared electromagnetic waves to the external environment by strengthening the infrared radiation characteristics of the material surface. This active heat radiation mechanism can effectively reduce the temperature peak and heat accumulation rate of the material surface, continuously control the material surface temperature in a safer range, thereby significantly improving the ablation resistance of the material and slowing down the evolution speed of ablation damage.

[0050] Specifically, the mass ratio of the ablation-resistant ceramic powder, the sintering-aid ceramic powder and the high-emissivity ceramic powder is (6-8):(4-6):(3-4).

[0051] Preferably, the particle size of the ablation-resistant ceramic powder, the sintering-aid ceramic powder and the high-emissivity ceramic powder is less than 2μm.

[0052] It should be noted that in the present application, the particle size of the ablation-resistant ceramic powder, the sintering-aid ceramic powder and the high-emissivity ceramic powder needs to be controlled to be less than 2 μm, on the one hand, which is more conducive to dispersion, so that the ablation-resistant ceramic powder, the sintering-aid ceramic powder and the high-emissivity ceramic powder are mixed more uniformly; on the other hand, the particle size less than 2 μm can be better laid on the surface of the fiber preform and penetrate into the interior of the fiber preform when the ceramic slurry is laid on the fiber preform.

[0053] Preferably, the ball milling conditions in step S1 include a ball milling speed of 400-700 rpm and a ball milling time of 0.5-2 h.

[0054] Preferably, the dispersing agent used in step S1 includes at least one of N-pyrrolidone, polyethylene glycol and silane coupling agent.

[0055] It should be noted that the dispersing agent can uniformly disperse the mixed ceramic powder through the adsorption of functional groups and the dispersion effect of solvation, preventing the occurrence of particle agglomeration.

[0056] Preferably, the binder includes at least one of polyvinylidene fluoride, polyvinyl alcohol and ammonium polyacrylate.

[0057] It should be noted that the binder increases the adhesion between the ceramic particles and the fiber preform, and the mass of the binder is 0.5-1.5% of the mass of the dispersing agent.

[0058] Further preferably, the mass concentration of the ceramic slurry is 20-40%.

[0059] It should be noted that too low slurry concentration will result in a larger penetration depth and less attached ceramic mass, and too high slurry concentration will result in poor penetration effect and agglomeration on the surface of the fiber preform.

[0060] Specifically, in step S2, the fiber roughening pretreatment includes at least one of plasma etching treatment, sandblasting roughening treatment and application of silane coupling agent treatment.

[0061] Preferably, the plasma etching rate is 50-300 nm / min, and the etching time is 20-100 s.

[0062] Preferably, the sandblasting roughening treatment time is 30-60 s, and the sandblasting pressure is 0.2-0.5 MPa.

[0063] Preferably, the coupling agent is at least one of 3-chloropropyltrimethoxysilane, 3-aminopropyltriethoxysilane, butyl triethoxy titanium and vinyl triethoxy silane.

[0064] Further preferably, the upper surface of the fiber preform is immersed in the silane coupling agent at room temperature for 10-30 minutes, and then dried in an oven at 60-80 DEG C for 1-2 hours.

[0065] It should be noted that after the roughening pretreatment, the fiber roughness Ra is greater than 0.5 μm, and the roughened fiber surface forms a more abundant micro concave-convex structure, which greatly increases the physical contact area between the two, so that the ceramic powder can be more closely attached to the fiber surface during the spraying process.

[0066] Meanwhile, the rough interface can also effectively improve the interface bonding strength through the enhancement of intermolecular forces and mechanical interlocking effect, and build a more stable fiber-ceramic interface bonding system. The interface bonding force between the fiber and the ceramic powder is significantly enhanced, and the ceramic powder can be more firmly anchored to the fiber surface, effectively resisting the impact and erosion of the heat flow, thereby maintaining the structural integrity and functional stability of the composite material in a high temperature environment.

[0067] Specifically, in step S2, the ceramic slurry is applied to the upper surface of the fiber preform by adopting a cyclic low-pressure cold spraying-drying process, and the number of cycles is 1-5.

[0068] Preferably, in the cyclic low-pressure cold spraying-drying process, the spraying pressure of the ceramic slurry is 0.3-1 MPa, the spraying temperature is 10-50 DEG C, the single spraying surface density is 0.08-0.18 g / m 2 .

[0069] Preferably, the drying temperature is 60-100 DEG C, the drying time is 1-4 hours, and the number of cycles is 1-5.

[0070] Preferably, the auxiliary oscillation frequency is 0.5-1.5 Hz, and the penetration depth is 10-30% of the thickness of the fiber preform.

[0071] It should be noted that the multiple cyclic low-pressure cold spraying-drying process adopted in the present application can realize efficient and controllable brushing weight, and thus control the overall density of the composite material; when the slurry concentration is controlled at 20-40%, the fluidity is moderate, which can not only increase the penetration efficiency of the ceramic components, but also prevent the slurry from being too poor in fluidity and thus being accumulated on the fiber surface, thereby affecting the subsequent RTM glue injection process.

[0072] The multiple cyclic cold spraying-drying process adopted in the present application can gradually densify the surface, thereby improving the ablation resistance of the material. After high-temperature oxyacetylene ablation, due to the sintering effect of the ceramic components, the ablated surface of the composite material is smooth and has increased hardness, which is beneficial to enhancing the mechanical properties of the material at high temperature.

[0073] Specifically, in step S2, the fiber preform is selected from carbon fibers, quartz fibers, phenolic fibers, mullite fibers, polyacrylonitrile fibers and silicon carbide fibers.

[0074] The fiber preform structure is a needle-punched web, a laminated needle-punched fabric / web, a 2.5D woven fabric, a right-angle three-way woven fabric or a three-dimensional multi-way woven fabric.

[0075] Specifically, the resin sol is a hybrid phenolic resin sol.

[0076] Specifically, in step S3, the RTM process has a glue injection pressure of 0.08-0.5 MPa and a glue injection time of 0.5-2 h; the curing temperature is 70-100℃, the curing time is 20-26 h, the drying temperature is 60-110℃, and the drying time is 18-26 h.

[0077] It should be noted that the hybrid phenolic resin sol used in the present application is prepared by existing methods, that is, an organic silicon source (such as silicon dioxide) or an inorganic silicon source (such as silane) is added to a catalyst; then phenolic resin is added for hybridization treatment to obtain a hybrid phenolic resin, and finally the hybrid phenolic resin sol is prepared. For example, it is prepared by using patent CN201911266938.7, or by using patent CN202410022559.8, or by using patent CN201610362815.3.

[0078] Specifically, the hybrid phenolic resin sol is prepared by using patent CN201911266938.7, which includes:

[0079] (1) Methyltrimethoxysilane is added to a reactor, and concentrated hydrochloric acid is then added, the molar amount of HCl in the concentrated hydrochloric acid being 4-6% of the methyltrimethoxysilane, and the mixture is heated to 70-85℃ for monomer polymerization, the reaction time being 36 h, and the mixture is condensed and refluxed to obtain high-molecular-weight organic silicon;

[0080] (2) Phenol, formaldehyde and hydrochloric acid are added to a reaction kettle, the molar ratio of phenol to formaldehyde being 7:10, and the molar ratio of HCl in the hydrochloric acid to phenol being 1:20, and after reaction at 70℃ for 1 h, phenolic resin is obtained, and the high-molecular-weight organic silicon obtained in step (1) is then added, and the mixture is heated to reflux at 90℃ for 3 h, and then the pH is adjusted to 6.8-7.2 to obtain organic silicon hybrid phenolic resin, which is then dissolved in isopropyl alcohol and a curing agent hexamethylenetetramine is added to obtain an organic silicon hybrid phenolic resin sol. The mass ratio of the high-molecular-weight organic silicon, the phenolic resin and the curing agent is 3:6:1, and the addition amount of isopropyl alcohol is adjusted to obtain a hybrid phenolic resin with a solid content of 30%-60%.

[0081] In order to more clearly describe the present application, the following examples and comparative examples are further described.

[0082] Embodiment 1

[0083] The preparation method of the function ceramic phase-nanopore resin ablation-resistant composite material comprises the following steps:

[0084] S1: Preparation of ceramic slurry; ablation-resistant ceramic powder, sintering-aid ceramic powder, and high-emissivity ceramic powder are mixed in proportion, with a mass ratio of 6:4:3, and after ball milling, a mixed powder with uniform composition is obtained; the mixed powder is added to the dispersant in batches, and after mixing, the ceramic slurry is obtained;

[0085] The ablation-resistant ceramic powder is a mixed powder of silicon carbide, silicon dioxide, and zirconium boride, with a melting point higher than 2600℃,

[0086] The sintering-aid ceramic powder is a low-melting-point glass powder, with a melting point of 650℃;

[0087] The high-emissivity ceramic powder is molybdenum silicide, with an emissivity of 0.85;

[0088] The ball milling is carried out at a speed of 500 revolutions per minute, and the ball milling time is 1h;

[0089] The mixed powder is added to N-pyrrolidone to prepare a ceramic slurry with a mass concentration of 30%, and 1% of N-pyrrolidone is added; then, a binder polyvinylidene fluoride is added, with a mass of 1.0% of the mass of N-pyrrolidone;

[0090] The particle size of all the powders is 100-1000nm;

[0091] S2: Preparation of the fiber preform loaded with the function ceramic phase; the upper surface of the fiber preform is subjected to fiber roughening pretreatment, then the ceramic slurry is applied to the upper surface of the fiber preform, and subsequently, auxiliary oscillation is used to promote uniform penetration of the slurry into the fiber, until a predetermined depth is reached, to obtain the fiber preform loaded with the function ceramic phase;

[0092] The fiber preform is a needled quartz fiber preform with a density of 0.27g / cm 3 The fiber roughening pretreatment is carried out by plasma etching process, with an etching rate of 50nm / min and an etching time of 60s;

[0093] The fiber preform is sprayed by using a multiple-cycle low-pressure spraying-drying process, with a spraying temperature of 40℃, a spraying pressure of 0.5MPa, and a control of the single-spraying density to be 0.1g / cm 2At the same time, auxiliary oscillation with a frequency of 0.8 Hz was carried out to make the ceramic components uniformly penetrate into 20% of the thickness of the fiber preform. A total of 1 spraying-drying process was carried out to obtain a fiber preform loaded with ceramic components with a density of 0.30 g / cm 3 ;

[0094] S3: Place the fiber preform loaded with ceramic powder in a mold and seal it. Inject a hybrid phenolic resin sol with a solid content of 40% (the hybrid phenolic resin sol is prepared according to patent CN201911266938.7) into the mold by RTM process. After curing at 90°C for 22h, and then curing at 80°C for 26h, a functional ceramic phase-nanoporous resin ablative-resistant composite material is prepared.

[0095] Example 2

[0096] Example 2 is generally the same as the preparation process of Example 1, except that 3 spraying-drying processes are carried out in Example 2 to obtain a fiber preform loaded with ceramic components with a density of 0.36 g / cm 3 .

[0097] Example 3

[0098] Example 3 is generally the same as the preparation process of Example 1, except that 5 spraying-drying processes are carried out in Example 3 to obtain a fiber preform loaded with ceramic components with a density of 0.42 g / cm 3 .

[0099] Example 4

[0100] Example 4 is generally the same as the preparation process of Example 1, except that the fiber preform used in step S2 of Example 4 is a needled quartz fiber preform with a density of 0.6 g / cm 3 . A total of 1 spraying-drying process is carried out to obtain a fiber preform loaded with ceramic components with a density of 0.63 g / cm 3 .

[0101] In step S3, the resin sol used is a hybrid phenolic resin sol with a solid content of 60%.

[0102] Example 5

[0103] Example 5 is generally the same as the preparation process of Example 1, except that the fiber preform used in step S2 of Example 5 is a needled quartz fiber preform with a density of 0.6 g / cm 3 . A total of 3 spraying-drying processes are carried out to obtain a fiber preform loaded with ceramic components with a density of 0.69 g / cm 3 .

[0104] In step S3, the resin sol used is a hybrid phenolic resin sol with a solid content of 60%.

[0105] Example 6

[0106] Example 6 is substantially the same as the preparation process of Example 1, except that the fiber preform used in step S2 of Example 6 is a 0.6 g / cm 3 needled quartz fiber preform, and a total of 5 spraying-drying processes are performed to obtain a fiber preform loaded with ceramic components with a density of 0.72 g / cm 3 .

[0107] In step S3, the resin sol used is a hybrid phenolic resin sol with a solid content of 60%.

[0108] Comparative Example 1

[0109] Comparative Example 1 is substantially the same as the preparation process of Example 1, except that step S1 and the fiber roughening pretreatment are not included in Comparative Example 1, and a needled quartz fiber preform with a bulk density of 0.27 g / cm 3 is directly placed into a mold and sealed, and then a hybrid phenolic resin sol with a solid content of 40% is injected through the RTM process, and after curing at 90°C for 22 h and then curing at 80°C for 26 h, a nano-porous resin-based composite material is prepared.

[0110] Comparative Example 2

[0111] Comparative Example 2 is substantially the same as the preparation process of Example 1, except that step S1 and the fiber roughening pretreatment are not included in Comparative Example 2, and a needled quartz fiber preform with a bulk density of 0.6 g / cm 3 is directly placed into a mold and sealed, and then a hybrid phenolic resin sol with a solid content of 60% is injected through the RTM process, and after curing at 100°C for 20 h and then curing at 80°C for 28 h, a nano-porous resin-based composite material is prepared.

[0112] Comparative Example 3

[0113] Comparative Example 3 is substantially the same as the preparation process of Example 1, except that the fiber roughening pretreatment is not performed in Comparative Example 3.

[0114] Comparative Example 4

[0115] Comparative Example 4 is substantially the same as the preparation process of Example 1, except that only the ablation-resistant ceramic powder is added in Comparative Example 4, and the slurry concentration is kept the same.

[0116] Performance detection

[0117] The above examples and comparative examples are subjected to performance detection, mainly including density detection, room temperature thermal conductivity detection, oxyacetylene ablation detection (1800℃, 300s), surface roughness detection after ablation, surface hardness detection after ablation. Among them, the density detection refers to the standard GB / T 1463-2005 "Fiber Reinforced Plastics Density and Relative Density Test Method"; the room temperature thermal conductivity detection adopts the flat plate heat flow method, and refers to the standard GB / T 10295-2008 "Thermal Insulation Material Steady-state Thermal Resistance and Related Characteristics Determination Heat Flow Meter Method"; the oxyacetylene ablation detection refers to the standard GJB 323B-2018 "Ablation Material Ablation Test Method"; the surface roughness detection refers to the standard GB / T 1031-2009 "Product Geometric Technical Specification (GPS) Surface Structure Contour Method Surface Roughness Parameter and Its Numerical Value"; and the surface hardness detection is tested by using a nano indentation device. The detection results are shown in Table 1.

[0118] Table 1 Performance detection results

[0119]

[0120] In combination with examples 1-6 and comparative examples 1-4 and referring to Table 1 and Figures 1-5 It can be seen that, by using the preparation method provided by the present application, the obtained composite material has low density and low thermal conductivity, and at the same time has high ablation resistance performance of thermal protection material. The density of the obtained composite material is 1.25g / cm 3 Hereinafter, the thermal conductivity is 0.123W / m -1 ·K -1 Hereinafter, the linear ablation rate is 4.85μm / s or less, the mass ablation rate is 1.239mg / s or less, the surface roughness is 103.4μm or less, and the surface hardness is 4.42GPa or more.

[0121] The above is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any change or replacement easily thought by those skilled in the art within the technical range disclosed by the present application should be covered within the protection scope of the present application.

Claims

1. A method for preparing a functional ceramic phase-nanoporous resin ablative-resistant composite material, characterized in that, The method comprises the following steps: S1: preparation of ceramic slurry; mixing ablation-resistant ceramic powder, sintering-aid ceramic powder and high-emissivity ceramic powder in a certain proportion, obtaining mixed powder after ball milling; adding the mixed powder into a dispersant, and then adding a binder to obtain the ceramic slurry; S2: preparation of a fiber preform loaded with functional ceramic phases; performing fiber roughening pretreatment on the upper surface of the fiber preform, applying the ceramic slurry on the upper surface of the fiber preform, and then obtaining the fiber preform loaded with functional ceramic phases through auxiliary oscillation; S3: placing the fiber preform in a mold, injecting a resin sol into the mold by using an RTM process, the resin sol being a hybrid phenolic resin sol, sealing the mold, and obtaining the functional ceramic phase-nanoporous resin ablation-resistant composite material through curing and normal-pressure drying; In step S2, the ceramic slurry is applied on the upper surface of the fiber preform through cyclic low-pressure cold spraying-drying treatment.

2. The method for preparing a functional ceramic phase-nanoporous resin ablation-resistant composite material according to claim 1, characterized in that, The ablation-resistant ceramic powder has a melting point higher than 2600℃. The ablation-resistant ceramic powder is selected from zirconium boride, silicon dioxide, silicon nitride, zirconium oxide, hafnium carbide and titanium carbide.

3. The preparation method of the functional ceramic phase-nanoporous resin ablation-resistant composite material according to claim 1, characterized in that, The sintering-aid ceramic powder is selected from low-melting-point glass powder, titanium dioxide, yttrium oxide, lanthanum oxide and cerium oxide.

4. The method for preparing a functional ceramic phase-nanoporous resin ablation-resistant composite material according to claim 1, characterized in that, The high-emissivity ceramic powder has an emissivity higher than 0.

85. The high-emissivity ceramic powder is selected from molybdenum silicide, chromium trioxide and silicon nitride.

5. The method for preparing a functional ceramic phase-nanoporous resin ablation-resistant composite material according to claim 1, characterized in that, The mass ratio of the ablation-resistant ceramic powder, the sintering-aid ceramic powder and the high-emissivity ceramic powder is (6-8):(4-6):(3-4).

6. The method for preparing a functional ceramic phase-nanoporous resin ablation-resistant composite material according to claim 1, characterized in that, In step S2, the fiber roughening pretreatment comprises at least one of plasma etching treatment, sandblasting roughening treatment or silane coupling agent treatment.

7. The method for preparing a functional ceramic phase-nanoporous resin ablation-resistant composite material according to claim 1, characterized in that, In step S2, the fiber preform is selected from carbon fiber, quartz fiber, phenolic fiber, mullite fiber, polyacrylonitrile fiber and silicon carbide fiber. The fiber preform has a structure of needle-punched web, laminated needle-punched fabric / web, 2.5D braiding, orthogonal three-way braiding or three-dimensional multi-way braiding structure.

8. A function ceramic phase-nanoporous resin ablative resistant composite material, characterized in that, The method is obtained by the preparation method of any one of claims 1-7.

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