A method for manufacturing an oxide ceramic matrix composite prepreg

Abstract

This invention belongs to the field of high-temperature structural materials and relates to a method for preparing oxide ceramic matrix composite prepreg. The method involves drying and curing an oxide sol, calcining, grinding, and screening to obtain ceramic powders of different particle sizes. Nanoscale sol, dispersant, and organic solvent are mixed uniformly to prepare a premixed precursor solvent. The powder is added to the premixed precursor solvent, and a thickener and stabilizer are added while stirring to obtain a ceramic suspension. Deionized water is added dropwise, and a pH adjuster is added while stirring. A fiber preform is impregnated in the prepreg slurry, removed, and subjected to hot-pressing semi-curing treatment to obtain the oxide ceramic matrix composite prepreg. This invention features a simple operation process, short preparation cycle, high purity and solid content in the prepreg slurry, good uniformity and stability, good wettability with fibers, and the ability to undergo a reversible gel semi-curing reaction. The resulting prepreg has a long storage period, is easy to transport, and is convenient to shear, allowing for one-step preparation of oxide ceramic matrix composites.

Description

Technical Field

[0001] This invention belongs to the field of oxide ceramic matrix composite material preparation technology, and relates to a method for preparing oxide ceramic matrix composite prepreg. Background Technology

[0002] Compared with non-oxide ceramic matrix composites, oxide ceramic matrix composites possess characteristics such as high strength, high modulus, low density, high temperature resistance, oxidation resistance, and resistance to water vapor corrosion, making them ideal candidate materials for applications in high-temperature and highly corrosive environments. They have broad application prospects in high-temperature structural materials fields such as warhead heat shields, aero-engines, ground gas turbines, and civilian industries, including components like the center cone, wavelet mixer, and combustion chamber lining of aero-engines, and the outer combustion chamber lining of gas turbines. Currently, the preparation methods for oxide ceramic matrix composites can be broadly divided into two categories: one uses ceramic micropowder as raw material to prepare the required matrix slurry, which is then filled with fiber preforms through impregnation or brushing, and finally densified to form the composite material; slurry-impregnation, electrophoretic deposition, winding, and hot pressing all belong to this category. The other category uses liquid precursors as raw materials, which undergo high-temperature pyrolysis and transformation to form an oxide matrix, ultimately yielding the composite material; precursor impregnation pyrolysis and sol-gel methods belong to this category. These methods for preparing oxide ceramic matrix composites are time-consuming, costly, and prone to damaging fibers during the preparation process, failing to meet market demands and industrial production requirements.

[0003] Prepreg processes for preparing oxide ceramic matrix composites offer advantages such as easy storage, simple operation, and suitability for large-scale industrial production, significantly shortening the preparation cycle and reducing composite material production costs. However, currently, domestically available ceramic powders and slurries are mainly suitable for preparing pure ceramics. Pure ceramics require high pressure to achieve low-temperature sintering, while oxide ceramic slurries have poor wettability with fibers. After drying, the ceramic powders do not adhere together and remain in a powder state, which is irreversible. This cannot achieve the semi-gel, semi-cured state required for prepregs and is therefore unsuitable for preparing oxide ceramic matrix composite prepregs. Consequently, no ideal preparation process for oxide ceramic matrix composite prepregs has been reported at present. Summary of the Invention

[0004] This invention proposes a novel method for preparing oxide ceramic matrix composite prepregs, addressing the problems existing in traditional oxide ceramic matrix composite prepreg processes.

[0005] To achieve the above objectives, the present invention is implemented using the following technical solution:

[0006] A method for preparing an oxide ceramic matrix composite prepreg includes the following steps.

[0007] (1) Mullite sol and alumina sol were dried and solidified by blowing air, calcined at high temperature, cooled and ground into powder, and then screened to obtain mullite micron powder, mullite nano powder, alumina micron powder and alumina nano powder respectively.

[0008] (2) Mix the nano-sized sol, dispersant and organic solvent evenly to obtain a premixed precursor solvent.

[0009] (3) The nano-sized mullite powder, micron-sized mullite powder, nano-sized alumina powder and micron-sized alumina powder are slowly added to the premixed precursor solvent and dispersed evenly. Then, thickener and stabilizer are added to obtain a mixed slurry. The mixture is stirred under vacuum to obtain a ceramic suspension.

[0010] (4) Add deionized water to the ceramic suspension to adjust the solid content and viscosity, then add pH adjuster and preservative, and stir under vacuum to obtain stable corundum-mullite ceramic prepreg slurry.

[0011] (5) Heat-treat the fiber to obtain a fiber preform, immerse the fiber preform in a stable corundum-mullite ceramic prepreg, remove it after immersion and perform hot-press semi-curing treatment to obtain an oxide ceramic matrix composite prepreg.

[0012] Preferably, in step (1), the solid content of mullite sol is 36-40%, and the average particle size is 10-40 nm; the solid content of alumina sol is 38-42%, and the average particle size is 1-10 nm; the drying temperature is 50-200℃, and the drying time is 2-6 h; the calcination temperature is 1000-1300℃, and the calcination time is 2-8 h; the average particle size of mullite micron powder is 1.03-5 μm, and the average particle size of mullite nanopowder is 0.15-0.3 μm; the average particle size of alumina micron powder is 0.8-3 μm, and the average particle size of alumina nanopowder is 0.1-0.25 μm.

[0013] Preferably, in step (2), the nano-sized sol is mullite sol or alumina sol; the dispersant is ammonium polyacrylate dispersant; the organic solvent is at least one of anhydrous ethanol, glycerol, and ethyl acetate; the mass ratio of nano-sized sol: dispersant: organic solvent is (20-30): (0.1-1): (10-20).

[0014] Preferably, in step (3), the mass ratio of nano-sized mullite powder: micron-sized mullite powder: nano-sized alumina powder: micron-sized alumina powder is (52-48): (13-12): (27-30): (9-10); the thickener is polyvinyl alcohol, and the mass fraction of the thickener in the mixed slurry is 1-3%; the stabilizer is a 2 mol / L nitric acid solution, and the mass fraction of the stabilizer in the mixed slurry is 1-3%; the mass fraction of the premixed precursor solvent in the mixed slurry is 40-50%.

[0015] Preferably, in step (4), deionized water is added to the ceramic suspension until the solid content is 45-55%, and the pH of the suspension is adjusted to 3-4 by a pH adjuster. The preservative is formaldehyde or salicylic acid, and the volume fraction of the preservative in the stable corundum-mullite ceramic prepreg is 0.01-0.05%.

[0016] Preferably, in step (5), the fiber is any one of alumina fiber, mullite fiber, quartz fiber, zirconium oxide fiber, or basalt fiber, the heat treatment temperature is 700-900℃, the heat treatment time is 5-120min, the impregnation time is 10s-10min, the hot pressing temperature is 65-150℃, the hot pressing pressure is 1-5MPa, and the hot pressing time is 10-30min.

[0017] The storage method for the oxide ceramic matrix composite prepreg prepared by the above method is as follows: a protective film is laid on the surface of the oxide ceramic matrix composite prepreg obtained in step (5), and then it is wound up and stored at a storage temperature of (-20)-10℃ and a storage humidity of 35-50%.

[0018] Based on domestic market demand, this invention explores a method for preparing a steady-state corundum-mullite ceramic slurry suitable for oxide ceramic matrix composite prepregs. The method is characterized by a long storage period, low sintering temperature, simple ceramicization process, short preparation cycle for oxide ceramic matrix composites, low preparation cost, and superior performance.

[0019] Compared with the prior art, the advantages and positive effects of the present invention are as follows:

[0020] 1. The prepreg process used in this invention for preparing oxide ceramic matrix composites is simple to operate, has a short preparation cycle, and is suitable for the industrial development of oxide ceramic matrix composites.

[0021] 2. After preparing a stable corundum-mullite prepreg, the fiber is impregnated. The prepreg has high purity, high solid content, good uniformity and stability, and good wettability with the fiber, and can undergo a semi-curing reversible reaction. The resulting oxide ceramic matrix composite prepreg has suitable size, long storage time, and low sintering temperature. Attached Figure Description

[0022] Figure 1 Photograph of the steady-state corundum-mullite ceramic prepreg slurry in Example 1.

[0023] Figure 2 This is a schematic diagram of the method for prepreg storage of the unidirectional reinforced oxide ceramic matrix composite material obtained in Example 1.

[0024] Figure 3 Fracture diagram of oxide ceramic matrix composite material prepared from unidirectional reinforced prepreg.

[0025] Figure 4 This is a schematic diagram of the method for prepreg storage of the multidirectional reinforced oxide ceramic matrix composite material prepared in Example 2.

[0026] Figure 5 SEM cross-sectional image of oxide ceramic matrix composite material prepared for multi-directional reinforcement prepreg. Detailed Implementation

[0027] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described below with reference to specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0028] Numerous specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways than those described herein, and therefore the invention is not limited to the specific embodiments disclosed in the following specification.

[0029] The mullite sol and alumina sol used in the following examples were both provided by Molun (Zhuhai) New Material Technology Co., Ltd. The mullite sol, model OX@CMC-OASC, has a solid content of 36%-40%, a viscosity ≤10cp at room temperature, an average particle size between 10-40nm, and a phase transformation temperature ≤1050℃. The sol contains abundant -Al-O-Si- bonds, which are key factors in the formation of the mullite phase at low temperatures. The alumina sol, model OX@CMCOAC, has a solid content of 38-42%, a viscosity ≤10cp at room temperature, and an average particle size between 1-10nm. It can achieve a semi-gel, semi-solid state under the temperature and pressure specified in this invention. After drying and calcination, both sols can be ground using a grinder or other methods to obtain powders with different particle size distributions. Powders with the required particle size are then screened for later use.

[0030] Example 1

[0031] 500g of mullite sol (model OX@CMC-OASC) and alumina sol (model OX@CMCOAC) were weighed and placed in a forced-air drying oven and dried at 200℃ for 2 hours. Then, they were placed in a muffle furnace and calcined at 1000℃ for 3 hours. After calcination, they were naturally cooled to room temperature and then ground using a grinder to obtain mullite powder and alumina powder of different particle sizes. The two types of powders were sieved separately, and spherical micron powder and spherical nano powder with uniform particle size distribution were selected for use. In this embodiment, the mullite micron powder had an average particle size of 1.52 μm, concentrated in the range of 1.03-5 μm, and a specific surface area (BET) of about 2.85. The mullite nano powder had an average particle size of 0.2 μm, concentrated in the range of 0.15-0.3 μm, and a specific surface area (BET) of about 11.2. The alumina micron powder had an average particle size of 1.02 μm, concentrated in the range of 0.8-3 μm, and a specific surface area (BET) of about 3.12. The alumina nano powder had an average particle size of 0.145 μm, concentrated in the range of 0.1-0.25 μm, and a specific surface area (BET) of about 12.1. The standard for measuring the particle size and distribution of the powder is GB / T 19077-2016.

[0032] OX@CMCOAC alumina sol was selected as the solvent. The small particle size of the alumina sol facilitates the formation of a cross-linked network system between the unidirectional fiber preforms, resulting in a denser lateral bond between the unidirectional preforms. 80 ml of alumina sol was measured, and 1.6 g of ammonium polyacrylate dispersant (Aisen SNF3000) and 48 g of anhydrous ethanol were added. The mixture was stirred at 200 rpm for 60 min to obtain the premixed precursor.

[0033] Slowly add 50.4g of mullite micron powder, 12.6g of mullite nanopowder, 27.75g of alumina micron powder, and 9.25g of alumina nanopowder in sequence. After mixing evenly, add 4.8ml of polyvinyl alcohol (Aladdin, Mowiol® PVA-210, average molar mass 6700) and 7.5ml of 2mol / L nitric acid solution, and mix evenly.

[0034] Add deionized water dropwise to the above mixture using a dropper until the solid content reaches 50%. Then, adjust the pH of the mixture to 3.6 using 3% dilute nitric acid. Finally, add 0.5g of salicylic acid and mix thoroughly to obtain a stable corundum-mullite ceramic prepreg slurry. Figure 1 .

[0035] Continuous alumina fibers (Morlion 857-1K, model: Morlion (Zhuhai) New Material Technology Co., Ltd.), with a diameter of 9-12 μm, were used. The fibers were placed in a high-temperature tube furnace for continuous heat treatment at 700℃ for 10 minutes. After heat treatment, the fibers were drawn into a second tube furnace at 50℃ for 10 minutes, allowing them to cool to 50℃. They were then impregnated in a corundum-mullite ceramic prepreg slurry for 30 seconds before being removed. The resulting oxide ceramic matrix composite prepreg was then subjected to hot-pressing semi-curing. In this embodiment, the hot pressing device consists of four sets of electromagnetic induction heating rollers. Each set has two heating rollers rotating in opposite directions, similar to the meshing arrangement of gears. The oxide ceramic matrix composite prepreg passes through the four sets of heating rollers under external force and the traction of the rolling motion of the heating rollers. The parameters of the four sets of electromagnetic induction heating rollers are identical: hot pressing temperature of 70℃, pressure of 3.5MPa, and total hot pressing time of 10-30 minutes. The hot pressing time is determined based on the state of the oxide ceramic matrix composite prepreg. The criteria are: the prepreg surface slurry has no flowability, the surface is glossy, fingerprints are left when pressed, it has a certain degree of stickiness, no delamination, the fiber volume fraction is 50%, and the thickness is between 0.15-0.2mm. In this embodiment, the actual average hot pressing time is 18 minutes and 25 seconds. After hot pressing, a unidirectional reinforced oxide ceramic matrix composite prepreg is obtained, with a width of 13cm and a length of 2m. Silicone paper protective film and polyethylene protective film are respectively laid on the upper and lower surfaces of the oxide ceramic matrix composite prepreg. Figure 2 As shown, after winding, it can be stored in a prepreg storage room for later use. The storage temperature is -20 to 10℃, the storage humidity is 35 to 50%, and the storage time can reach more than 60 days.

[0036] The oxide ceramic matrix composite prepreg prepared above can be used directly or stored and used as needed. To test its performance, ten 100*10mm pieces of the unidirectional reinforced oxide ceramic matrix composite prepreg prepared in this embodiment were cut with a blade and placed in a mold of the same specification for molding and curing. The mold curing temperature was set to 200℃, the total time was 2 hours, and the heating rate was 2℃ / min. After curing, the samples were allowed to cool naturally to room temperature, demolded, and placed in a muffle furnace for high-temperature treatment at 1200℃ for 2 hours at a heating rate of 2℃ / min. Then, they were allowed to cool naturally to room temperature to obtain the ceramic matrix composite. The tensile properties of this material were tested according to GJB 8736-2015, "Test Method for Tensile Properties of Continuous Fiber Reinforced Ceramic Matrix Composites at Room Temperature". The test results showed that the tensile strength of the material at room temperature was 403 MPa, and the room temperature tensile modulus was 130 GPa. Samples were taken from the first day (…). Figure 3 a) Day 5 ( Figure 3 b), Day 10 ( Figure 3 c) The thirtieth day ( Figure 3 d) The sixty-fifth day ( Figure 3 e) The prepreg was molded under the same conditions and then treated at high temperature to prepare composite materials for testing. The test results showed toughness fracture, and the properties remained basically unchanged. The fracture surface photographs are shown below. Figure 3 As shown.

[0037] Example 2

[0038] Unless otherwise specified, this embodiment is consistent with Example 1. In the preparation of the premixed precursor in this embodiment, mullite sol of type OX@CMC-OASC is used as the solvent. Mullite sol contains abundant -Al-Si-O- bonds, which facilitates the wetting of ceramic slurry into the woven fiber. 100 ml of mullite sol was measured, and 2 ml of ammonium polyacrylate dispersant and 60 ml of glycerol were added. The mixture was stirred at 25°C and 200 rpm for 45 min to obtain the premixed precursor.

[0039] 51g of mullite micron powder, 12.5g of mullite nanopowder, 28g of alumina micron powder, and 9.6g of alumina nanopowder were added slowly in sequence and mixed evenly. Then, 5.2ml of polyvinyl alcohol (Aladdin, Mowiol® PVA-210, with an average molar mass of 6700) and 7.8ml of 2mol / L nitric acid solution were added. The mixture was stirred at 750 rpm for 5 hours under vacuum. Then, deionized water was added dropwise to achieve a solid content of 50%. The pH of the mixture was adjusted to about 3.5 using 3% dilute nitric acid. The zeta potential of the slurry was found to be 52.1±5.1mV and the viscosity was 51±1.2cp, resulting in a stable corundum-mullite ceramic slurry.

[0040] A continuous alumina fiber satin-woven fabric (Morlion (Zhuhai) New Material Technology Co., Ltd., model Morlion857-1k-5HS) was used. This fabric was 13 cm wide and 0.15 mm thick. One meter of the fabric was taken for each operation and placed in a muffle furnace for surface heat treatment at 700℃ for 30 minutes. The heat-treated continuous alumina fiber preform was then impregnated in a stable corundum-mullite ceramic prepreg, followed by hot-pressing semi-curing. The criteria for semi-curing were: no flowability of the prepreg surface, a glossy surface, fingerprints when pressed, a certain degree of stickiness, and a smooth surface. Testing showed that the fiber volume fraction in the material obtained after impregnation and hot pressing in this embodiment was 48%, and the thickness was 0.2 mm-0.3 mm. In this embodiment, the hot-pressing temperature was 80℃, the pressure was 2 MPa, and the hot-pressing time was 5 minutes.

[0041] Finally, both sides are covered with a polyethylene protective film on the surface of the oxide ceramic matrix composite material before being rolled up and stored. Figure 4 As shown, the storage temperature in the storage room is -20℃ to 10℃, the storage humidity is 35% to 50%, and the storage time can reach more than 60 days, and the performance of the composite prepreg remains basically unchanged.

[0042] To test the performance of the composite prepreg obtained in this embodiment, prepregs prepared and those stored for seventy days were heat-treated at 1150℃ for 1 hour to obtain ceramic matrix composites. Tensile properties were then tested on these materials (the tests were performed according to the standard "GJB 8736-2015 Test Method for Tensile Properties of Continuous Fiber Reinforced Ceramic Matrix Composites at Room Temperature"). The results showed that the room temperature tensile strength of the composite obtained from the prepared prepreg was 365 MPa, and the room temperature tensile modulus was 123 GPa; the room temperature tensile strength of the prepreg stored for seventy days was 363 MPa, and the room temperature tensile modulus was 124 GPa. The SEM cross-sectional images are shown below. Figure 5 As shown in Figures a and 5b, it can be seen from the figures that there is no obvious delamination in the cross-section of either material, the internal pores are evenly distributed, and the material properties remain basically unchanged after 70 days of storage.

[0043] Comparative Example 1

[0044] Unless otherwise specified, this comparative example and the following comparative examples are consistent with Example 1. This comparative example changes the ratio of micron-sized powder to nano-sized powder, while the ratio of the two sols in each powder group remains consistent with Example 1. Experiments were conducted using pure micron-sized powder, a micron-to-nano powder mass ratio of 6:1, a micron-to-nano powder mass ratio of 1:2, and pure nano-sized powder. The results showed that the final ceramic matrix all exhibited varying degrees of cracking, while the ceramic matrix composite material obtained in the examples showed no cracking. This demonstrates that an excessively high or low ratio of nano-sized powder to micron-sized powder can negatively impact product performance.

[0045] Comparative Example 2

[0046] The difference between this comparative example and the previous example lies in the following: the solid content of the corundum-mullite ceramic prepreg slurry was adjusted by changing the amount of deionized water added, and the effect of pH on the zeta potential of the slurry was detected by adding 3% dilute nitric acid. pH affects the charge density and quantity on the surface of the powder in the solution, thus affecting the magnitude of the zeta potential. When the pH of the slurry is between 3 and 4, the zeta potential of the slurry is the largest. The higher the absolute value of the zeta potential, the greater the repulsion and the more stable the system. When the pH is below 3 or above 4, the prepreg slurry exhibits stratification after standing. Impregnation tests were conducted on slurries with solid contents of 39% and 65%, respectively. It was found that excessively high or low solid contents both resulted in poor fiber wettability, and the prepared oxide ceramic matrix composite prepreg had an uneven surface and increased internal defects.

[0047] Comparative Example 3

[0048] In this comparative example, the semi-curing temperature was increased to 150°C. It was found that the gel curing reaction of the slurry was too fast, resulting in the prepreg being completely dried and cured. The gel time was difficult to control, and the prepreg would harden, making it impossible to wind up or use it to prepare composite materials. Further, the semi-curing temperature was set to 50°C. As a result, the gel curing reaction was slower, the gel time was longer, and the slurry remained in a fluid state for a short period of time, making it impossible to wind up and store.

[0049] Comparative Example 4

[0050] In this comparative example, the semi-curing pressure was set to 5 MPa. The results showed that during the semi-curing process, the ceramic slurry was easily extruded, resulting in an excessively high fiber volume fraction in the prepreg, which was detrimental to prepreg preparation and subsequent composite material molding. Further setting the semi-curing pressure to 0.8 MPa resulted in slurry aggregation, increased matrix content, and a reduced toughening effect on the oxide ceramic matrix composite.

[0051] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments for application in other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A method for preparing an oxide ceramic matrix composite prepreg, characterized in that, The steps are as follows: (1) Mullite sol and alumina sol were dried and solidified by blowing air, calcined at high temperature, cooled and ground into powder, and then screened to obtain mullite micron powder, mullite nano powder, alumina micron powder and alumina nano powder respectively. (2) The nano-sized sol, dispersant and organic solvent are mixed evenly to prepare a premixed precursor solvent; the nano-sized sol is mullite sol or alumina sol; (3) Mullite nanopowder, mullite micropowder, alumina nanopowder and alumina micropowder are slowly added to the premixed precursor solvent and dispersed evenly. Then thickener and stabilizer are added to obtain a mixed slurry. Stir under vacuum to obtain a ceramic suspension. The mass ratio of mullite nanopowder: mullite micron powder: alumina nanopowder: alumina micron powder is (13-12): (52-48): (9-10): (27-30). (4) Add deionized water to the ceramic suspension to adjust the solid content and viscosity, then add pH adjuster and preservative, stir under vacuum to obtain stable corundum-mullite ceramic prepreg slurry; add deionized water to the ceramic suspension until the solid content is 45-55%, and adjust the pH of the suspension to 3-4 with pH adjuster. (5) Heat-treat the fiber to obtain a fiber preform, impregnate the fiber preform in a stable corundum-mullite ceramic prepreg, remove it after impregnation and perform hot-press semi-curing treatment to obtain an oxide ceramic matrix composite prepreg; the hot-pressing temperature is 65-80℃, the hot-pressing pressure is 1-3.5MPa, and the hot-pressing time is 10-30min. In step (1), the solid content of mullite sol is 36-40%, and the average particle size is 10-40 nm; the solid content of alumina sol is 38-42%, and the average particle size is 1-10 nm; the drying temperature is 50-200℃, and the drying time is 2-6 h; the calcination temperature is 1000-1300℃, and the calcination time is 2-8 h; the average particle size of mullite micron powder is 1.03-5 μm, and the average particle size of mullite nano powder is 0.15-0.3 μm. The average particle size of alumina micron powder is 0.8-3 μm, and the average particle size of alumina nano powder is 0.1-0.25 μm.

2. The method for preparing the oxide ceramic matrix composite prepreg according to claim 1, characterized in that, In step (2), the dispersant is an ammonium polyacrylate dispersant; the organic solvent is at least one of anhydrous ethanol, glycerol, and ethyl acetate; the mass ratio of nano-sized sol: dispersant: organic solvent is (20-30): (0.1-1): (10-20).

3. The method for preparing the oxide ceramic matrix composite prepreg according to claim 1, characterized in that, In step (3), the thickener is polyvinyl alcohol, and the mass fraction of the thickener in the mixed slurry is 1-3%; the stabilizer is a 2 mol / L nitric acid solution, and the mass fraction of the stabilizer in the mixed slurry is 1-3%; the mass fraction of the premixed precursor solvent in the mixed slurry is 40-50%.

4. The method for preparing the oxide ceramic matrix composite prepreg according to claim 1, characterized in that, The preservative mentioned in step (4) is formaldehyde or salicylic acid, and the volume fraction of the preservative in the steady-state corundum-mullite ceramic prepreg slurry is 0.01-0.05%.

5. The method for preparing the oxide ceramic matrix composite prepreg according to claim 1, characterized in that, In step (5), the fiber is any one of alumina fiber, mullite fiber, quartz fiber, zirconium oxide fiber, or basalt fiber. The heat treatment temperature is 700-900℃, the heat treatment time is 5-120min, and the impregnation time is 10s-10min.

6. A method for storing the oxide ceramic matrix composite prepreg prepared by the method of claim 1 or 5, characterized in that, A protective film is applied to the surface of the oxide ceramic matrix composite prepreg obtained in step (5), and the prepreg is then wound up and stored at a temperature of (-20) -10℃ and a humidity of 35-50%.

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