Ultrahigh-temperature ceramic-based composite material and preparation method thereof

Abstract

The invention provides an ultrahigh-temperature ceramic-based composite material and a preparation method thereof, and the preparation method comprises the following steps: depositing an interface layer on the surface of a carbon fiber preform through a chemical vapor deposition process to obtain a fiber reinforcement; preparing a first ceramic phase on the surface of the fiber reinforcement with the interface layer by adopting a precursor impregnation cracking process to obtain a ceramic phase modified composite material; sequentially dipping, curing and cracking the ceramic phase modified composite material by adopting modified resin mixed slurry to obtain a multi-scale porous carbon matrix; and carrying out infiltration densification on the multi-scale porous carbon matrix by taking second ceramic phase powder as a raw material to obtain the ultrahigh-temperature ceramic-based composite material. According to the preparation method disclosed by the invention, efficient introduction of an ultra-high-temperature ceramic phase is realized through coordination of triple processes and multi-scale pore regulation and control, and the ultra-high-temperature ceramic-based composite material with excellent high-temperature resistance, ablation resistance and mechanical property is prepared.

Description

Technical Field

[0001] The present invention relates to the technical field of thermal protection materials, and in particular to an ultra-high temperature ceramic-based composite material and a preparation method thereof. Background Art

[0002] Ceramic-based composites (CMCs) have broad application prospects in the aerospace field due to their high-temperature resistance, high specific strength, and high fracture toughness. Currently, common preparation processes for CMCs include chemical vapor deposition (CVD), precursor infusion pyrolysis (PIP), and reactive metal infiltration (RMI).

[0003] Chemical vapor deposition (CVD) achieves material densification through gas-phase pyrolysis deposition of small molecules, but this method is not suitable for thick-walled samples; the precursor impregnation and pyrolysis method (PIP) densifies through repeated impregnation-curing-pyrolysis of the precursor, which often requires several impregnation-pyrolysis cycles, has a long production cycle, and it is difficult to prepare completely dense materials; the metal melt infiltration reaction method (RMI) is to melt the refractory metal at high temperature and infiltrate it into the porous sample, and then react with the reactive matrix in the porous body in situ to form a ceramic matrix, but its high-temperature melt erosion of the fiber reaction will lead to performance degradation, and the residual metal will affect the high-temperature thermal stability and mechanical properties of the composite material.

[0004] Based on this, there is an urgent need to provide an ultra-high temperature ceramic-based composite material and a preparation method thereof. Summary of the Invention

[0005] The embodiments of the present invention provide an ultra-high temperature ceramic-based composite material and a preparation method thereof, which can solve the problem that the introduction of a high temperature ceramic phase using a traditional process easily causes fiber damage and cannot achieve efficient introduction of the ultra-high temperature ceramic phase.

[0006] In a first aspect, the present invention provides a method for preparing an ultra-high temperature ceramic-based composite material, the method comprising the following steps:

[0007] (1) depositing an interface layer on the surface of a carbon fiber preform by a chemical vapor deposition process to obtain a fiber reinforcement having an interface layer;

[0008] (2) preparing a first ceramic phase on the surface of a fiber reinforcement having an interface layer by a precursor impregnation and cracking process to obtain a ceramic phase modified composite material; wherein the first ceramic phase is one or more of zirconium carbide or hafnium carbide;

[0009] (3) impregnating, curing, and cracking the ceramic phase modified composite material in sequence with a modified resin mixed slurry to obtain a multi-scale porous carbon matrix;

[0010] (4) Using a second ceramic phase powder as a raw material, the multi-scale porous carbon matrix is ​​subjected to melt infiltration and densification to obtain the ultra-high temperature ceramic-based composite material; wherein the second ceramic phase powder is one or more of silicon-zirconium alloy powder or silicon-hafnium alloy powder.

[0011] Preferably, in step (1), the carbon fiber preform is one of a needle-punched preform, a puncture preform or a stitched preform.

[0012] Preferably, the density of the carbon fiber preform is 0.4-0.8 g / cm 3 .

[0013] Preferably, in step (1), the interface layer is a pyrolytic carbon interface layer, and the number of deposited interface layers is n, where n is 3 to 6 and is a natural number.

[0014] Preferably, in step (1), when depositing the interface layer, the deposition temperature is 900-1000° C., and the thickness of the single-layer interface layer is 0.1-0.4 μm.

[0015] More preferably, in step (2), the volume fraction of the first ceramic phase introduced on the surface of the fiber reinforcement having the interface layer by the precursor impregnation and cracking process is 15-25%.

[0016] Preferably, in step (2), the single impregnation ceramic cracking yield through the precursor impregnation cracking process is ≥25wt%, the number of impregnation-curing-cracking cycles is 4-8, the cracking temperature is 1500-1600°C, and the time for each cracking is 2-4h.

[0017] Preferably, in step (3), the modified resin mixed slurry is obtained by mixing phenolic resin and a pore-forming agent; wherein the pore-forming agent includes a micron-scale pore-forming agent and a nano-scale pore-forming agent.

[0018] More preferably, the micron-scale pore-forming agent is polymethyl methacrylate, and the nano-scale pore-forming agent is one or more of polyethylene glycol and polyethylene oxide.

[0019] Preferably, in step (3), the contents of the components in the phenolic resin mixed slurry are as follows, in percentage by mass: 40-60% phenolic resin, 15-30% micron-sized pore-forming agent, and 15-30% nano-sized pore-forming agent.

[0020] Preferably, in step (3), the vacuum degree of the impregnation is 5-100 kPa, and the vacuum impregnation time is 1-2 h; the curing temperature is 150-350 ° C, the curing pressure is 3-10 MPa, and the curing time is 1-2 h; the cracking temperature is 700-1000 ° C, and the cracking time is 2-4 h.

[0021] Preferably, in step (4), the mass ratio of zirconium atoms or hafnium atoms in the second ceramic phase powder is 10-30%.

[0022] Preferably, in step (4), the temperature of the infiltration densification is 1400-1500° C., and the time is 1-2 h.

[0023] In a second aspect, the present invention provides an ultra-high temperature ceramic-based composite material prepared by the preparation method described in any one of the first aspects above.

[0024] Compared with the prior art, the present invention has at least the following beneficial effects:

[0025] (1) In the present invention, an interface layer is first deposited on the surface of a carbon fiber preform by a CVD method, and then a large amount of ZrC / HfC ceramic phase is pre-introduced on the surface of the fiber reinforcement with the interface layer by a PIP method. Then, a modified resin mixed slurry containing a pore-forming agent is used to impregnate, solidify and crack the ceramic phase modified composite material, thereby constructing multi-scale pores on the surface of the ceramic phase modified composite material. Finally, a high-temperature resistant ceramic phase is further introduced by a silicon infiltration process. The above process can not only increase the volume fraction of the ultra-high temperature ceramic phase in the composite material to more than 28%, so that the composite material can still maintain stable structural strength in an ultra-high temperature environment above 2200°C; at the same time, it can significantly reduce the direct contact area and reaction intensity between the ceramic phase alloy melt and the carbon fiber in the subsequent infiltration process, reduce the damage depth of the fiber-matrix interface, and thus improve the mechanical properties of the composite material.

[0026] (2) In the present invention, the three processes of CVD-PIP-RMI are coordinated to form an integrated preparation path of "fiber protection-ultra-high temperature ceramic skeleton prefabrication-efficient densification". Compared with a single process or a simple combination process, this process not only avoids the defects of long densification cycle and serious fiber damage, but also achieves an increase in the volume fraction of the ultra-high temperature ceramic phase and high density, thereby improving the high temperature ablation resistance and high temperature mechanical properties of the composite material. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0028] Figure 1 This is a SEM image of the cross-sectional morphology of an ultra-high temperature ceramic-based composite material provided in Example 1 of the present invention. DETAILED DESCRIPTION

[0029] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0030] The embodiment of the present application provides a preparation method of an ultrahigh-temperature ceramic matrix composite material, which comprises the following steps:

[0031] (1) depositing an interface layer on the surface of a carbon fiber preform through a chemical vapor deposition process to obtain a fiber reinforced body with the interface layer;

[0032] (2) preparing a first ceramic phase on the surface of the fiber reinforced body with the interface layer by using a precursor impregnation and pyrolysis process to obtain a ceramic phase modified composite material; wherein the first ceramic phase is one or more of zirconium carbide or hafnium carbide;

[0033] (3) sequentially performing impregnation, curing and pyrolysis on the ceramic phase modified composite material by using a modified resin mixed slurry to obtain a multi-scale porous carbon matrix;

[0034] (4) densifying the multi-scale porous carbon matrix by using a second ceramic phase powder as a raw material to obtain the ultrahigh-temperature ceramic matrix composite material; wherein the second ceramic phase powder is one or more of a silicon-zirconium alloy powder or a silicon-hafnium alloy powder.

[0035] In the embodiment of the present application, first, an interface layer is deposited on the surface of a carbon fiber preform by a CVD method, then a large number of ZrC / HfC ceramic phases are introduced on the surface of the fiber reinforced body with the interface layer by a PIP method, and then impregnation, curing and pyrolysis are performed on the ceramic phase modified composite material by using a modified resin mixed slurry containing a pore-forming agent, so as to construct a multi-scale porous structure on the surface of the ceramic phase modified composite material, and finally a high-temperature-resistant ceramic phase is further introduced by a silicon infiltration process. Through the above process, the volume fraction of the ultrahigh-temperature ceramic phase in the composite material can be increased to more than 28%, so that the composite material can still maintain stable structural strength in an ultrahigh-temperature environment of more than 2200℃. At the same time, the direct contact area and reaction intensity of the ceramic phase alloy melt and the carbon fiber in the subsequent infiltration process can be significantly reduced, and the damage depth of the fiber matrix interface can be reduced, so as to improve the mechanical properties of the composite material.

[0036] According to some preferred embodiments, in step (1), the carbon fiber preform is one of a needled preform, a pierced preform or a stitched preform; the density of the carbon fiber preform is 0.4-0.8 g / cm 3(0.4g / cm 3 , 0.5g / cm 3 , 0.55g / cm 3 , 0.7g / cm 3 or 0.8g / cm 3 ).

[0037] According to some preferred embodiments, in step (1), the interface layer is a pyrolytic carbon interface layer, the number of layers of the interface layer is n layers (for example, can be 3 layers, 4 layers, 5 layers or 6 layers), n is 3-6 and n is a natural number; when depositing the interface layer, the deposition temperature is 900-1000℃ (for example, can be 900℃, 910℃, 920℃, 930℃, 940℃, 950℃, 960℃, 970℃, 980℃ or 1000℃), and the thickness of a single layer of the interface layer is 0.1-0.4μm (for example, can be 0.1μm, 0.2μm, 0.3μm or 0.4μm).

[0038] In the embodiments of the present application, first, a pyrolytic carbon interface layer is deposited on the surface of the carbon fiber preform by a chemical vapor deposition process, so that adverse reactions between the carbon fiber preform and the matrix during the subsequent modification process can be prevented, and the bonding force between the two can be enhanced; and the number of layers of the deposited pyrolytic carbon interface layer is preferably 3-5 layers, and by controlling the thickness of each layer, not only can the damage to the fibers when introducing high-temperature ceramic phases such as zirconium carbide / hafnium carbide in the subsequent process be effectively avoided, but also the mechanical properties and oxidation resistance of the composite material can be enhanced.

[0039] It should be noted that the precursors and other process parameters used in the embodiments of the present application for depositing the pyrolytic carbon interface layer by the chemical vapor deposition process are not specifically limited, as long as the required number of layers and thickness can be achieved, and specific adjustments can be made according to actual needs.

[0040] According to some preferred embodiments, in step (2), the volume fraction of the first ceramic phase introduced on the surface of the fiber reinforced body with the interface layer by the precursor impregnation and pyrolysis process is 15-25% (for example, can be 15%, 20% or 25%); the ceramic pyrolysis yield of a single impregnation by the precursor impregnation and pyrolysis process is ≥25wt% (for example, can be 25%, 30%, 35% or 40%); the number of impregnation-curing-pyrolysis cycles is 4-8 cycles (for example, can be 4, 5, 6, 7 or 8 cycles); the pyrolysis temperature is 1500-1600℃ (for example, can be 1500℃, 1510℃, 1520℃, 1530℃, 1540℃, 1550℃, 1560℃, 1570℃, 1580℃ or 1600℃); and the time for each pyrolysis is 2-4h (for example, can be 2h, 3h, 4h).

[0041] Considering that in the process of directly introducing ultra-high temperature ceramic phase into fiber reinforcement by relying solely on silicon infiltration, the high temperature metal melt (Zr / Hf) is prone to cause oxidation damage or interface reaction degradation to carbon fibers, and the content of ultra-high temperature ceramic phase is limited by the composition ratio of high temperature metal. For example, if the Zr / Hf content is too high, the melting temperature and melt viscosity will be significantly increased, thereby leading to problems such as aggravated carbon fiber damage and interfacial stress cracking, which greatly increases the process difficulty and equipment requirements. Based on the above problems, in an embodiment of the present invention, a large amount of ZrC / HfC ultra-high temperature ceramic phase is pre-introduced on the surface of the fiber reinforcement of the deposition interface layer by using the PIP process. On the one hand, it can increase the content of ultra-high temperature ceramic phase in the composite material. On the other hand, the ultra-high temperature ceramic phase can act as an intermediate barrier, significantly reducing the direct contact area and reaction intensity between the ultra-high temperature metal melt and the carbon fibers in the subsequent silicon infiltration process, reducing the depth of interface damage, thereby effectively solving the dual technical bottlenecks of "low content of ultra-high temperature ceramic phase" and "serious fiber damage" in the traditional single silicon infiltration process.

[0042] In an embodiment of the present invention, by controlling various parameters during the PIP process, a certain volume fraction of the first ceramic phase (ZrC / HfC) is introduced, which not only effectively reduces the damage depth of the ultra-high temperature metal melt to the carbon fiber interface during the subsequent silicon infiltration process, but also facilitates the subsequent introduction of the ultra-high temperature ceramic phase through silicon infiltration. Ultimately, the volume fraction of the ultra-high temperature ceramic phase in the composite material can be increased to more than 28%, thereby not only enabling the composite material to maintain stable structural strength in an ultra-high temperature environment above 2200°C, but also significantly improving the mechanical properties of the composite material.

[0043] It should be noted that in the embodiment of the present invention, the type of impregnation slurry and other parameters used in the process of introducing the first ceramic phase (ZrC / HfC) by the precursor impregnation pyrolysis (PIP) process are not specifically limited. As long as the introduction of the first ceramic phase with a specific volume fraction can be achieved, the specific parameters can be selected according to actual needs.

[0044] According to some preferred embodiments, in step (3), the modified resin mixed slurry is obtained by mixing phenolic resin and a pore-forming agent; wherein the pore-forming agent includes a micron-scale pore-forming agent and a nano-scale pore-forming agent; preferably, the micron-scale pore-forming agent is polymethyl methacrylate, and the nano-scale pore-forming agent is one or more of polyethylene glycol or polyethylene oxide.

[0045] According to some preferred embodiments, the multi-scale pores of the multi-scale porous carbon matrix include micropores of 1-20 μm and nanopores of 10-350 nm.

[0046] In view of the single pore structure of the carbon fiber matrix in the traditional process, local residual carbon enrichment and metal segregation are prone to occur, in the embodiment of the present application, a modified resin mixed slurry is formed by adding a certain content of micron and nanometer pore-forming agents to the phenolic resin, and the mixed slurry is used for impregnation-curing-pyrolysis of the ceramic phase modified composite material, so as to build a hierarchical pore structure of micron and nanometer micropores on the surface of the ceramic phase modified composite material, the micron channel can improve the silicon infiltration efficiency, and the nanometer pore can enhance the uniformity and controllability of the silicon infiltration reaction, which can not only significantly reduce the residual carbon / metal content on the surface of the composite material, but also realize the rapid improvement of the density of the composite material, so that the porosity of the final composite material is reduced to below 5%, effectively solving the technical problems of "non-uniform reaction" and "low densification efficiency" in the traditional process.

[0047] According to some preferred embodiments, in step (3), the content of each component in the phenolic resin mixed slurry is as follows: phenolic resin 40-60% (for example, it can be 40%, 42%, 44%, 46%, 48%, 50%, 52%, 54%, 56%, 58% or 60%), micron pore-forming agent 15-30% (for example, it can be 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29% or 30%), and nanometer pore-forming agent 15-30% (for example, it can be 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29% or 30%).

[0048] In the embodiment of the present application, by synergistically controlling the content of phenolic resin, micron pore-forming agent and nanometer pore-forming agent in the mixed slurry, high silicon infiltration efficiency and good reaction uniformity can be realized at the same time, thereby significantly reducing the residual carbon / metal content on the surface of the composite material and realizing the rapid improvement of the density of the composite material; however, if the content of the micron pore-forming agent is too high, the micron pore on the surface of the material will be too much, which will reduce the carbon content of the material and adversely affect the mechanical properties and thermal insulation properties of the composite material; and if the content of the nanometer pore-forming agent is too high, not only will the nanometer particles agglomerate during the impregnation process, but also it will be difficult to ensure the good uniformity and high efficiency of the subsequent silicon infiltration reaction.

[0049] According to some preferred embodiments, in step (3), the vacuum degree of the impregnation is 5-100 kPa (for example, 5 kPa, 10 kPa, 20 kPa, 30 kPa, 40 kPa, 50 kPa, 60 kPa, 70 kPa, 80 kPa, 90 kPa or 100 kPa), and the vacuum impregnation time is 1-2 h (for example, 1 h, 1.5 h or 2 h); the curing temperature is 150-350 ° C (for example, 150 ° C, 200 ° C, 25 0℃, 300℃ or 350℃), the curing pressure is 3-10Mpa (for example, it can be 3Mpa, 4Mpa, 5Mpa, 6Mpa, 7Mpa, 8Mpa, 9Mpa or 10MPa), and the curing time is 1-2h (for example, it can be 1h, 1.5h or 2h); the cracking temperature is 700-1000℃ (for example, it can be 700℃, 800℃, 900℃ or 1000℃), and the cracking time is 2-4h (for example, it can be 2h, 3h, or 4h).

[0050] In the embodiment of the present invention, by precisely controlling the ratio of each raw material component in the mixed slurry and synergistically optimizing the impregnation, curing and cracking process parameters, micron-scale pores and nano-scale pores are effectively introduced on the surface of the ceramic phase-modified composite material, forming a modified composite material matrix with multi-scale pores, and the multi-scale pore structure has a uniform pore size distribution, which can not only significantly reduce the residual carbon / metal content on the surface of the composite material, but also enhance the uniformity and controllability of the subsequent silicon infiltration reaction, while achieving a rapid increase in the density of the composite material.

[0051] According to some preferred embodiments, in step (4), the mass ratio of zirconium atoms or hafnium atoms in the second ceramic phase powder is 10-30% (for example, it can be 10%, 12%, 14%, 16%, 18%, 20%, 22%, 24%, 26%, 28% or 30%).

[0052] According to some preferred embodiments, in step (4), the temperature of the infiltration densification is 1400-1500°C (for example, it can be 1400°C, 1410°C, 1420°C, 1430°C, 1440°C, 1450°C, 1460°C, 1470°C, 1480°C or 1500°C), and the time is 1-2h (for example, it can be 1h, 1.5h or 2h).

[0053] In the embodiment of the present application, by using silicon-zirconium powder or silicon-hafnium powder as raw material, the multi-scale porous carbon matrix is densified by infiltration, and by reasonably controlling the content of super-high-temperature metal atoms in the silicon-zirconium powder and the silicon-hafnium powder, the super-high-temperature ceramic phase (SiC and ZrC / HfC) can be further formed on the surface of the first ceramic phase (ZrC / HfC) under the condition of ensuring a low silicon infiltration temperature and without damaging the carbon fibers, thereby forming a super-high-temperature ceramic matrix composite material with excellent temperature resistance, ablation resistance and mechanical properties.

[0054] In summary, in the embodiment of the present application, the present application forms an integrated preparation path of “fiber protection-super-high-temperature ceramic skeleton preform-high-efficiency densification” through the cooperation of CVD-PIP-RMI three processes. Compared with single process or simple combined process, the above process cooperation avoids the defects of long densification cycle and serious fiber damage, realizes the increase of the volume fraction of the super-high-temperature ceramic phase and high density, and improves the high-temperature ablation resistance and high-temperature mechanical properties of the composite material.

[0055] The present application also provides a super-high-temperature ceramic matrix composite material prepared by the preparation method of any one of the above.

[0056] In the embodiment of the present application, the super-high-temperature ceramic matrix composite material comprises a carbon fiber preform; the surface of the carbon fiber preform comprises, in sequence, a pyrolytic carbon interface protective coating deposited by CVD, a first ceramic phase (ZrC / HfC) introduced by PIP and a ceramic phase (SiC and ZrC / HfC) formed by RMI. The prepared composite material has a low porosity (porosity ≤ 5%), the content of ZrC / HfC or the total content of both in the super-high-temperature ceramic phase in the composite material is ≥ 28%, the residual metal zirconium / hafnium content is ≤ 1.5 wt%, the high-temperature tensile strength is not less than 130 MPa, the high-temperature bending strength is not less than 220 MPa, and the temperature resistance can reach above 2200℃.

[0057] In order to more clearly illustrate the technical solutions and advantages of the present application, the following embodiments are used to specifically explain a super-high-temperature ceramic matrix composite material and a preparation method thereof.

[0058] Embodiment 1:

[0059] (1) 4 layers of pyrolytic carbon interface layers are deposited on the surface of a carbon fiber preform (a needled preform with a density of 0.55 g / cm 3 The deposition temperature is 940℃, the thickness of a single pyrolytic carbon interface layer is 0.3 μm, a total of 4 layers are deposited, and the total thickness of the pyrolytic carbon interface layers is 1.2 μm;

[0060] (2) a hafnium carbide ceramic precursor was used to perform seven rounds of impregnation-curing-pyrolysis on a fiber reinforcement having an interface layer to prepare a first ceramic phase (HfC ceramic phase) on the surface of the fiber reinforcement having an interface layer, thereby obtaining a ceramic phase-modified composite material; wherein the pyrolysis temperature was 1600°C, the pyrolysis time was 2 h, the single pyrolysis ceramic yield was 40%, and a total volume fraction of 16% of the HfC ceramic phase was introduced;

[0061] (3) The ceramic phase modified composite material is sequentially impregnated (impregnation vacuum degree is 10 kPa, impregnation time is 1 h), cured (curing temperature is 300 ° C, curing pressure is 4 MPa, curing time is 2 h) and cracked (cracking temperature is 1000 ° C, cracking time is 2 h) with a modified resin mixed slurry to obtain a multi-scale porous carbon matrix (including micropores of 10-20 μm and nanopores of 25-300 nm); wherein the modified resin mixed slurry is obtained by mixing 25% polymethyl methacrylate, 25% polyethylene oxide, and 50% phenolic resin;

[0062] (4) The multi-scale porous carbon matrix was densified by melt infiltration using the second ceramic phase powder (Hafnium silicon alloy with 24% hafnium atoms and 76% silicon atoms) as the raw material to obtain an ultra-high temperature ceramic-based composite material; wherein the melt infiltration temperature was 1500°C and the time was 2h.

[0063] Example 2:

[0064] Example 2 is basically the same as Example 1, except that: in step (2), the fiber reinforcement with an interface layer is subjected to 7 rounds of impregnation-curing-cracking using a zirconium carbide ceramic precursor to prepare a first ceramic phase (ZrC ceramic phase) on the surface of the fiber reinforcement with an interface layer; the cracking temperature is 1500°C, the cracking time is 2h, the single cracking ceramic yield is 28%, and a total volume fraction of 19% of the ZrC ceramic phase is introduced.

[0065] Example 3:

[0066] Example 3 is basically the same as Example 1, except that: in step (2), a zirconium carbide ceramic precursor is used to perform 7 rounds of impregnation-curing-cracking on the fiber reinforcement with an interface layer to prepare a first ceramic phase (ZrC ceramic phase) on the surface of the fiber reinforcement with an interface layer; the cracking temperature is 1500°C, the cracking time is 2h, the single cracking ceramic yield is 28%, and a total volume fraction of 19% of the ZrC ceramic phase is introduced; in step (4), the second ceramic phase powder includes a hafnium silicon alloy with a zirconium atom ratio of 18% and a silicon atom ratio of 82%, the infiltration temperature is 1500°C, and the time is 2h.

[0067] Example 4:

[0068] Example 4 is basically the same as Example 1, except that: in step (2), the fiber reinforcement having an interface layer is subjected to 15 rounds of impregnation-curing-cracking using a hafnium carbide ceramic precursor to prepare a first ceramic phase (HfC ceramic phase) on the surface of the fiber reinforcement having an interface layer to obtain a ceramic phase-modified composite material; wherein the cracking temperature is 1600°C, the cracking time is 2h, the single cracking ceramic yield is 40%, and a total volume fraction of 26% of the HfC ceramic phase is introduced.

[0069] Example 5:

[0070] Example 5 is basically the same as Example 1, except that: in step (2), the fiber reinforcement with an interface layer is subjected to four rounds of impregnation-curing-cracking using a hafnium carbide ceramic precursor to prepare a first ceramic phase (HfC ceramic phase) on the surface of the fiber reinforcement with an interface layer to obtain a ceramic phase-modified composite material; wherein the cracking temperature is 1600°C, the cracking time is 2h, the single cracking ceramic yield is 40%, and a total volume fraction of 14% of the HfC ceramic phase is introduced.

[0071] Example 6:

[0072] Example 6 is basically the same as Example 1, except that in step (3), the modified resin mixed slurry is obtained by mixing 35% polymethyl methacrylate, 15% polyethylene oxide, and 50% phenolic resin.

[0073] Example 7:

[0074] Example 7 is basically the same as Example 1, except that in step (3), the modified resin mixed slurry is obtained by mixing 15% polymethyl methacrylate, 35% polyethylene oxide, and 50% phenolic resin.

[0075] Comparative Example 1

[0076] Comparative Example 2 is substantially the same as Comparative Example 1, except that step (2) is not performed, ie, the HfC ceramic phase is not prepared on the surface of the fiber reinforcement having the interface layer.

[0077] Comparative Example 2

[0078] Comparative Example 2 is substantially the same as Comparative Example 1, except that in step (3), the resin mixture slurry is composed only of phenolic resin, and a porous carbon matrix with a pore size ranging from 100 nm to 300 nm is obtained.

[0079] Comparative Example 3

[0080] Comparative Example 3 is substantially the same as Comparative Example 1, except that in step (3), the modified resin mixed slurry is obtained by mixing 50% polymethyl methacrylate and 50% phenolic resin.

[0081] Comparative Example 4

[0082] Comparative Example 4 is substantially the same as Comparative Example 1, except that in step (3), the modified resin mixed slurry is obtained by mixing 50% polyethylene oxide and 50% phenolic resin.

[0083] The ultra-high temperature ceramic matrix composite materials in Examples 1 to 6 and Comparative Examples 1 to 4 were subjected to performance tests. The test results are shown in Tables 1 and Figure 1 shown.

[0084] Porosity test: refer to GB / T 21650.1-2008 Mercury intrusion method and gas adsorption method for pore size distribution and porosity of solid materials Part 1: Mercury intrusion method for testing;

[0085] Residual Metal Content Test: The operation method is as follows: the sample is cut into 3mm*4mm*5mm squares, placed in a 5vol% HF aqueous solution for corrosion for 48 hours, and the weight change of the sample before and after corrosion is measured to determine the residual Zr / Hf content in the ultra-high temperature ceramic-based composite material.

[0086] The calculation formula is:

[0087]

[0088] Where R Zr / Hf is the residual Zr or Hf rate (%) in the ultra-high temperature ceramic matrix composite; M1 and M2 are the masses of the dry sample before and after corrosion, respectively, and ρ Z r / Hf is the density of Zr or Hf, ρ V is the density of the composite material;

[0089] High-temperature tensile performance test: The test is carried out in accordance with GJB 10311-2021 Test method for high-temperature mechanical properties of continuous fiber reinforced ceramic matrix composites; the high-temperature flexural performance test is carried out in accordance with GJB 10311-2021 Test method for high-temperature mechanical properties of continuous fiber reinforced ceramic matrix composites.

[0090] Table 1

[0091]

[0092]

[0093] Combined with Table 1 and Figure 1It can be known that the ultrahigh-temperature composite material prepared in the embodiment has excellent temperature resistance and mechanical properties, the temperature resistance temperature can be up to 2200 DEG C or above, and the high-temperature tensile strength at 1600 DEG C is not less than 130 MPa, and the high-temperature bending strength is not less than 220 MPa.

[0094] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application, but not limited to them; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for preparing an ultra-high temperature ceramic-based composite material, characterized in that: The preparation method comprises the following steps: (1) depositing an interface layer on the surface of a carbon fiber preform by a chemical vapor deposition process to obtain a fiber reinforcement; (2) preparing a first ceramic phase on the surface of a fiber reinforcement having an interface layer by a precursor impregnation and cracking process to obtain a ceramic phase modified composite material; wherein the first ceramic phase is one or more of zirconium carbide or hafnium carbide; (3) impregnating, curing, and cracking the ceramic phase modified composite material in sequence with a modified resin mixed slurry to obtain a multi-scale porous carbon matrix; (4) Using a second ceramic phase powder as a raw material, the multi-scale porous carbon matrix is ​​subjected to melt infiltration and densification to obtain the ultra-high temperature ceramic-based composite material; wherein the second ceramic phase powder is a silicon-zirconium alloy powder or a silicon-hafnium alloy powder.

2. The preparation method according to claim 1, characterized in that In step (1), the carbon fiber preform is one of a needle-punched preform, a puncture preform, or a stitched preform; Preferably, the density of the carbon fiber preform is 0.4-0.8 g / cm 3 .

3. The preparation method according to claim 1, characterized in that In step (1), the interface layer is a pyrolytic carbon interface layer, and the number of deposited interface layers is n layers, where n is 3 to 6 and is a natural number; and / or When depositing the interface layer, the deposition temperature is 900-1000° C., and the thickness of the single-layer interface layer is 0.1-0.4 μm.

4. The preparation method according to claim 1, characterized in that In step (2), the volume fraction of the first ceramic phase introduced on the surface of the fiber reinforcement having the interface layer by the precursor impregnation and pyrolysis process is 15-25%; and / or The single impregnation ceramic cracking yield of the precursor impregnation cracking process is ≥25wt%, the impregnation-curing-cracking rounds are 4-8 rounds, the cracking temperature is 1500-1600°C, and the time of each cracking is 2-4h.

5. The preparation method according to claim 1, characterized in that In step (3), the modified resin mixed slurry is obtained by mixing phenolic resin and a pore-forming agent; wherein the pore-forming agent includes a micron-scale pore-forming agent and a nano-scale pore-forming agent; Preferably, the micron-scale pore-forming agent is polymethyl methacrylate, and the nano-scale pore-forming agent is one or more of polyethylene glycol and polyethylene oxide.

6. The preparation method according to claim 5, characterized in that In step (3), the contents of the components in the phenolic resin mixed slurry are as follows, in percentage by mass: 40-60% phenolic resin, 15-30% micron-scale pore-forming agent, and 15-30% nano-scale pore-forming agent.

7. The preparation method according to claim 1, characterized in that In step (3), the vacuum degree of the impregnation is 5-100 kPa, and the vacuum impregnation time is 1-2 hours; the curing temperature is 150-350° C., the curing pressure is 3-10 MPa, and the curing time is 1-2 hours; the cracking temperature is 700-1000° C., and the cracking time is 2-4 hours.

8. The preparation method according to claim 1, characterized in that In step (4), the mass ratio of zirconium atoms or hafnium atoms in the second ceramic phase powder is 10-30%.

9. The preparation method according to claim 1, characterized in that In step (4), the temperature of the infiltration densification is 1400-1500° C., and the time is 1-2 hours.

10. An ultra-high temperature ceramic-based composite material, characterized in that: The preparation method according to any one of claims 1 to 9 is used for preparation.

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