Alumina fiber reinforced oxide matrix composite material and preparation method thereof

Abstract

The invention discloses an alumina fiber reinforced oxide matrix composite material and a preparation method thereof, and belongs to the technical field of composite materials. The preparation method comprises the following steps: adding MgO powder into oxide nano powder as a sintering aid, then adding aluminum oxide sol to prepare a solution, adding ammonium polyacrylate into the solution as a dispersing agent to prepare slurry, and fully and uniformly stirring; spreading the degummed Al2O3 fiber cloth, uniformly smearing the slurry on the two surfaces of the degummed Al2O3 fiber cloth, and stacking to obtain a fiber cloth laminated layer; coating the outer side of the fiber cloth laminated layer with demolding cloth, smearing silicone grease on the side surface, close to the fiber cloth laminated layer, of the demolding cloth, respectively placing glass on the upper and lower parts of the demolding cloth, placing a breathable felt on the glass on the upper layer, then integrally placing in a vacuum bag, sealing the vacuum bag, vacuumizing and curing, and then carrying out heat treatment. And preparing the alumina fiber reinforced oxide matrix composite material. According to the preparation method, a slurry formula and an Al2O3 fiber cloth lamination preparation and vacuum packaging structure are optimized, the preparation method combines slurry impregnation with a vacuum bag pressing method, the flow process is simple, and the preparation method is suitable for being used as a selection scheme for large-scale production.

Description

Technical Field

[0001] The present invention belongs to the technical field of composite materials, and particularly relates to an alumina fiber reinforced oxide matrix composite material and a preparation method thereof. Background Art

[0002] With the rapid development of high-end industries and engineering technologies, the requirements for material properties are becoming increasingly stringent, especially for components working in extreme environments, such as in the fields of aerospace, automotive, and energy. The application scenarios in these fields usually require materials to have excellent thermal stability, mechanical strength, oxidation resistance, thermal shock resistance, and good corrosion resistance. However, traditional single-metal or ceramic materials often exhibit problems such as insufficient mechanical properties, poor high-temperature resistance, and thermal expansion mismatch under these harsh conditions, and cannot meet the needs of modern engineering.

[0003] Alumina fiber (Al2O3f) has high strength, modulus, and good high-temperature resistance, and can maintain good mechanical properties and structural stability at high temperatures. By introducing alumina fiber into the oxide matrix, the prepared alumina fiber reinforced oxide matrix composite material (Al2O3f / oxide composites) exhibits excellent high-temperature resistance, oxidation resistance, mechanical properties, and thermal stability in extreme environments. By introducing alumina fiber into the oxide matrix, the thermal stability, oxidation resistance, and thermal shock resistance of the composite material can be effectively improved, thereby enhancing its application potential in extreme environments such as high temperature and high corrosion. Alumina fiber reinforced oxide matrix composite materials are considered to be high-performance materials with important prospects.

[0004] Literature 1 "C.H. Zhu, F. Cao, Y. Xiang, Effects of sintering temperature on mechanical properties of alumina fiber reinforced alumina matrix composites. Journal of Sol-Gel Science and Technology, 2020, 93: 185–192." uses the sol-gel method to prepare Al2O3 / Al2O3 composites. The alumina fiber preform needs to be impregnated, cured, and sintered in alumina sol multiple times to finally obtain a densified Al2O3 / Al2O3 composite material.

[0005] Reference 2 "W.W. Li, X.H. Fan, N. Ni, X.F. Zhao, C.W. Li, et al. Continuous alumina fiber-reinforced yttria-stabilized zirconia composites with high density and toughness. Journal of the European Ceramic Society, 2020, 40(4): 1539-1548." prepared alumina fiber-reinforced yttria-stabilized zirconia composites using the spark plasma sintering (SPS) method. The SPS method cannot prepare composites with complex structures, which limits its application in engineering.

[0006] Reference 3 "Chen Huiling. A method for non-autoclave forming of composites. CN118124171A, 2024, 06, 04." prepared composites using a method of hot pressing a preform with a pressure roller combined with a vacuum bag. After hot pre-compacting the prepreg layer by layer to the target number of layers or thickness, the preform was then encapsulated and cured.

[0007] However, the preparation processes and techniques of the current methods for preparing alumina fiber-reinforced composites are relatively complex and time-consuming. Summary of the Invention

[0008] To overcome the above-mentioned drawbacks of the prior art, the object of the present invention is to provide an alumina fiber-reinforced oxide matrix composite material and its preparation method, which optimize the slurry formula, the preparation of the Al2O3 fiber cloth laminate, and the vacuum packaging structure. This preparation method is prepared by slurry impregnation combined with the vacuum bag pressing method, with a simple process flow and is suitable as an alternative for large-scale production.

[0009] To achieve the above object, the present invention adopts the following technical solutions:

[0010] The present invention provides a method for preparing an alumina fiber-reinforced oxide matrix composite material, comprising the following steps:

[0011] Adding MgO powder as a sintering aid to the oxide nano-powder, then adding alumina sol to obtain a solution, and adding ammonium polyacrylate as a dispersant to the solution to obtain a slurry and stirring it evenly.

[0012] Lay the degummed Al2O3 fiber cloth flat, evenly apply the slurry on both sides of the degummed Al2O3 fiber cloth, and stack several layers of degummed Al2O3 fiber cloth to obtain a fiber cloth stack; wrap the release cloth outside the fiber cloth stack, apply silicone grease on the side of the release cloth close to the fiber cloth stack, place glass on the upper and lower parts of the release cloth respectively, place a breathable felt on the upper glass, and then place the whole in a vacuum bag. After sealing the vacuum bag, evacuate and cure, and then perform heat treatment to obtain an alumina fiber reinforced oxide matrix composite material.

[0013] In one embodiment, the oxide nano-powder is Al2O3 nano-powder and ZrO2-8Y nano-powder with a mass ratio of 1.5-2:1, pure Al2O3 nano-powder, or TiO2 nano-powder and Nb2O5 nano-powder with a mass ratio of 5.5-6:1.

[0014] In one embodiment, the particle size of the oxide nano-powder is not greater than 500 nm.

[0015] In one embodiment, the MgO powder is 0.1%-0.5% of the mass of the oxide nano-powder.

[0016] In one embodiment, the volume fraction of the oxide nano-powder and MgO powder in the solution is 50-55 vol%.

[0017] In one embodiment, the solid content of the alumina sol is not less than 20%, the average particle size is not greater than 20 nm, the viscosity is not greater than 50 mPa·s, and the pH value is 3.5-4.0.

[0018] In one embodiment, the mass of the ammonium polyacrylate is 0.1-1% of the total mass of the oxide nano-powder and MgO powder.

[0019] In one embodiment, the release cloth is a polytetrafluoroethylene dispersion resin film.

[0020] In one embodiment, the curing is carried out in an oven, the curing temperature is 160 °C, and the curing time is 2 h;

[0021] The heat treatment is carried out in an air or argon gas atmosphere, the heat treatment temperature is 1000-1200 °C, and the heat treatment time is 2 h.

[0022] The present invention also provides an alumina fiber reinforced oxide matrix composite material prepared by the preparation method of the above alumina fiber reinforced oxide matrix composite material.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The present invention provides a method for preparing an alumina fiber reinforced oxide matrix composite material, and a dense alumina fiber reinforced oxide matrix composite material is obtained. This preparation method is a method for preparing an alumina fiber reinforced oxide matrix composite material by slurry impregnation combined with vacuum bag pressing. Using alumina sol as the slurry solvent increases the slurry viscosity, and a dispersant is added inside the slurry to increase the slurry stability. The preparation and vacuum packaging structure of the Al2O3 fiber cloth laminate are designed and optimized. Among them, silicone grease is added as a fixing layer, so that the slurry can be stored to a greater extent inside the composite material during vacuum impregnation. The glass can convert the free compaction of the vacuum pressure into controlled molding. Combining the design of the release cloth and the surface silicone grease, compared with the existing vacuum bag structure, it can inhibit fiber sliding, reduce material deformation, and make the prepared composite material flat with as few pores as possible. The unique feature of the present invention is that the slurry composition and the vacuum bag structure are optimized, and various alumina fiber reinforced oxide matrix composite materials can be prepared. Description of the Drawings

[0025] Figure 1 is a schematic diagram of the vacuum bag structure;

[0026] Figure 2 is the morphology of the composite material prepared in Example 1;

[0027] Figure 3 is the micro-morphology of the composite material prepared in Example 1;

[0028] Figure 4 is the dielectric property measured for the composite material prepared in Example 1;

[0029] Figure 5 is the morphology of the composite material prepared in Example 2;

[0030] Figure 6 is the micro-morphology of the composite material prepared in Example 2;

[0031] Figure 7 is the flexural mechanical property measured for the composite material prepared in Example 2;

[0032] Figure 8 is the morphology of the composite material prepared in Example 3;

[0033] Figure 9 is the micro-morphology of the composite material prepared in Example 3;

[0034] Figure 10 is the mechanical property measured for the composite material prepared in Example 3. Detailed Embodiments

[0035] To enable those skilled in the art to understand the features and effects of the present invention, the following provides a general description and definition of the terms and phrases mentioned in the specification and claims. Unless otherwise specified, all technical and scientific terms used herein shall have the ordinary meaning understood by those skilled in the art regarding the present invention. In case of conflict, the definition in this specification shall prevail.

[0036] The theories or mechanisms described and disclosed herein, whether correct or incorrect, shall in no way limit the scope of the present invention, that is, the content of the present invention can be implemented without being limited by any specific theory or mechanism.

[0037] In this article, all features defined in the form of numerical ranges or percentage ranges, such as numerical values, quantities, contents, and concentrations, are only for the sake of brevity and convenience. Accordingly, the description of a numerical range or percentage range should be regarded as having covered and specifically disclosed all possible sub-ranges and individual values within the range (including integers and fractions).

[0038] In this article, unless otherwise specified, the terms "comprising", "including", "containing", "having", or similar terms cover the meanings of "consisting of" and "consisting essentially of". For example, "A comprises a" covers the meanings of "A comprises a and others" and "A consists only of a".

[0039] In this article, for the sake of concise description, all possible combinations of all technical features in each embodiment or example are not described. Therefore, as long as there is no contradiction in the combination of these technical features, the technical features in each embodiment or example can be combined arbitrarily, and all possible combinations should be considered as being within the scope described in this specification.

[0040] On the one hand, the present invention provides a method for preparing an alumina fiber-reinforced oxide matrix composite material. The specific process is as follows:

[0041] Step 1: Add MgO powder as a sintering aid to the oxide nano-powder, then add alumina sol to obtain a solution, and add ammonium polyacrylate as a dispersant to the solution to obtain a slurry and stir it evenly.

[0042] The above-mentioned oxide nano-powder is any one of A, B, and C; wherein, A is a mixture of Al2O3 nano-powder and ZrO2-8Y nano-powder, and their mass ratio is 1.5 - 2:1; B is pure Al2O3 nano-powder; C is a mixture of TiO2 nano-powder and Nb2O5 nano-powder, and their mass ratio is 5.5 - 6:1.

[0043] The particle size of the above-mentioned oxide nano-powder is not more than 500 nm. MgO powder is added as a sintering aid, and its mass is 0.1-0.5% of the mass of the powder already added. Alumina sol is added until the volume fraction of the oxide nano-powder and MgO powder in the solution is 50-55 vol%. The solid content of the alumina sol is not less than 20%, the average particle size is not more than 20 nm, the viscosity is not more than 50 mPa·s, and the pH value is 3.5-4.0. 0.1-1% of poly(acrylate ammonium) is added to the prepared solution as a dispersant.

[0044] The process of fully stirring evenly is as follows:

[0045] Put the prepared slurry into a ball mill. The rotation speed of the ball mill is 300-500 rpm, and ball milling is carried out for 2-5 h to make the slurry fully stirred evenly.

[0046] Aluminum oxide in the oxide nano-powder has high hardness and good mechanical properties, and is wear-resistant, high-temperature resistant, and corrosion-resistant. It has good compatibility with alumina fibers and is suitable as an oxide matrix. Yttria-stabilized zirconia (ZrO2-8Y) has high hardness and wear resistance, relatively high mechanical properties, excellent high-temperature phase stability, high chemical inertness and corrosion resistance, and good compatibility with alumina, and is suitable as a reinforcing matrix for alumina. Rutile titanium oxide has the advantages of high temperature resistance, low temperature resistance, corrosion resistance, high strength, and small specific gravity, and has a relatively high dielectric constant. By doping niobium oxide, the conductivity of titanium oxide can be enhanced, and then the overall wave-absorbing performance of the composite material can be enhanced.

[0047] Step 2: Lay the degummed Al2O3 fiber cloth flat, evenly apply the prepared slurry on both sides of the degummed Al2O3 fiber cloth, and stack several layers of degummed Al2O3 fiber cloth to obtain a fiber cloth laminate; the vacuum bag is designed as shown in the appendix Figure 1 Select a polytetrafluoroethylene dispersion resin film (PTFE film) as the release cloth, evenly apply silicone grease on the inner side of the PTFE film close to the fiber cloth, wrap the stacked fiber cloth, place fixed-shaped glasses on the upper and lower sides of the PTFE film, place a layer of breathable felt on the upper glass, place a vacuum chuck and a suction nozzle on the breathable felt, wrap the above structure with a vacuum bag after placement and seal it with a sealing machine. The vacuum suction nozzle is connected to a vacuum pump, start the vacuum pump, put the vacuum bag into an oven, and cure it at 160 °C for 2 h; heat-treat the cured laminate sample, and heat-treat it at 1000-1200 °C for 2 h in a gas atmosphere to obtain an alumina fiber-reinforced oxide matrix composite material.

[0048] Among them, the degumming process is to heat-treat the Al2O3 fiber cloth at 600 °C in air for 2 h. The gas atmosphere is an argon atmosphere or an air atmosphere.

[0049] In the above steps, the degummed Al2O3 fiber cloth is laid flat, coated with slurry on both sides and then laminated to form a fiber cloth laminate. The outer layer of the laminate is wrapped with a release cloth, and a silicone grease (which serves as a lubricant / heat conductor) is coated on the inner interface of the release cloth to form an easily demoldable structure. Glass plates are placed above and below the release cloth to play a role in shaping and fixing, and a breathable felt is covered on the upper glass surface (which is beneficial for the discharge of gas during the vacuum process). The whole is placed into a vacuum bag, and the materials are closely bonded through vacuum pumping.

[0050] On the other hand, the present invention provides a method for rapidly preparing various alumina fiber-reinforced oxide matrix composites by using the above preparation method and optimizing the slurry configuration and the vacuum bag structure.

[0051] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.

[0052] Conventional instrument and equipment in the art are used in the following embodiments. For the experimental methods without specific conditions noted in the following embodiments, they are usually carried out under conventional conditions or according to the conditions recommended by the manufacturer. Various raw materials are used in the following embodiments. Unless otherwise specified, commercially available products are used, and their specifications are conventional specifications in the art. In the specification of the present invention and the following embodiments, unless otherwise specified, "%" represents weight percentage, "parts" represents weight parts, and the ratio represents weight ratio.

[0053] Example 1

[0054] This example provides a method for preparing an alumina fiber-reinforced oxide matrix composite, and the specific process is as follows:

[0055] (1) Take 24.36 g of Al2O3 nano-powder and 14.4 g of ZrO2-8Y nano-powder, add 0.04 g of MgO, add alumina sol until the powder volume fraction is 55 vol%, and add 1% of ammonium polyacrylate as a dispersant to the prepared solution;

[0056] (2) Put the prepared slurry into a ball mill, the rotation speed of the ball mill is 400 rpm, and ball mill for 3 h to fully stir and mix the slurry evenly;

[0057] (3) Lay the degummed Al2O3 fiber cloth flat, evenly apply the prepared slurry on both sides of the degummed fiber cloth and stack them. Evenly apply silicone grease on the inner side of the PTFE film close to the fiber cloth, wrap the stacked fiber cloth, place a glass with a fixed shape on the PTFE film, place a layer of breathable felt on the upper glass, place a vacuum chuck and a suction nozzle on the breathable felt. After placement, wrap the above structure with a vacuum bag and seal it with a sealing machine. The vacuum suction nozzle is connected to a vacuum pump;

[0058] (4) Start the vacuum pump, put the vacuum bag into the oven, and cure it at 160 °C for 2 h;

[0059] (5) Heat-treat the cured laminated specimen, heat-treat it at 1200 °C for 2 h in an argon atmosphere. The heat-treated specimen is as Figure 2 shown, and its microstructural photo is as Figure 3 shown. The prepared ceramic matrix is dense and covers the surface of the fiber cloth. The measured dielectric properties are as Figure 4 shown. In the range of 12 - 18 GHz, the tangent value of the dielectric loss angle fluctuates between 0.1 - 0.7, and the maximum can reach 0.7.

[0060] Example 2

[0061] This example provides a preparation method for an alumina fiber-reinforced oxide matrix composite material. The specific process is as follows:

[0062] (1) Take 50 g of Al2O3 nano-powder, add 0.25 g of MgO, add alumina sol until the powder volume fraction is 55 vol%, and add 1% of ammonium polyacrylate as a dispersant to the prepared solution;

[0063] (2) Put the prepared slurry into a ball mill, the rotation speed of the ball mill is 400 rpm, and ball mill for 2 h to make the slurry fully stirred and evenly mixed;

[0064] (3) Lay the degummed Al2O3 fiber cloth flat, evenly apply the prepared slurry on both sides of the degummed fiber cloth and stack them. Evenly apply silicone grease on the inner side of the PTFE film close to the fiber cloth, wrap the stacked fiber cloth, place a glass with a fixed shape on the PTFE film, place a layer of breathable felt on the upper glass, place a vacuum chuck and a suction nozzle on the breathable felt. After placement, wrap the above structure with a vacuum bag and seal it with a sealing machine. The vacuum suction nozzle is connected to a vacuum pump;

[0065] (4) Start the vacuum pump, put the vacuum bag into the oven, and cure it at 160 °C for 2 h;

[0066] (5) Heat-treat the cured laminated specimen, heat-treat it at 1000 °C for 2 h in an air atmosphere. The heat-treated specimen is as Figure 5 shown, and its microstructural photo is as Figure 6As shown, the matrix wraps the fibers to form a dense matrix layer, and the measured flexural mechanical properties are as Figure 7 shown. The porosity is 33%, the flexural strength can reach 225.75 Mpa, and the flexural modulus reaches 104.72 GPa.

[0067] Example 3

[0068] This example provides a method for preparing an alumina fiber reinforced oxide matrix composite. The specific process is as follows:

[0069] (1) Take 40 g of TiO2 nano powder, 7 g of Nb2O5 nano powder, add 0.05 g of MgO, add alumina sol until the powder volume fraction is 50 vol%, and add 0.1% of ammonium polyacrylate as a dispersant to the prepared solution;

[0070] (2) Put the prepared slurry into a ball mill, the ball mill speed is 300 rpm, and ball mill for 2 h to make the slurry fully stirred and uniform;

[0071] (3) Lay the degummed Al2O3 fiber cloth flat, evenly apply the prepared slurry on both sides of the degummed fiber cloth and stack them. Evenly apply silicone grease on the inner side of the PTFE film close to the fiber cloth, wrap the stacked fiber cloth, place a glass with a fixed shape on the PTFE film, place a layer of breathable felt on the upper glass, place a vacuum chuck and a suction nozzle on the breathable felt. After placing, wrap the above structure with a vacuum bag and seal it with a sealing machine. The vacuum suction nozzle is connected to a vacuum pump;

[0072] (4) Start the vacuum pump, put the vacuum bag into the oven, and cure at 160 °C for 2 h;

[0073] (5) Heat-treat the cured laminated specimen, heat-treat at 1200 °C for 2 h in an argon atmosphere. The heat-treated specimen is as Figure 8 shown, and its microstructure photograph is as Figure 9 shown. The ceramic matrix densely covers the fiber surface, and the measured dielectric properties are as Figure 10 shown. In the range of 12 - 18 GHz, the tangent value of the dielectric loss angle fluctuates between 0.1 - 0.45, and the maximum can reach 0.45.

[0074] Example 4

[0075] This example provides a method for preparing an alumina fiber reinforced oxide matrix composite. The specific process is as follows:

[0076] (1) Take 30 g of Al2O3 nano powder, 15 g of ZrO2-8Y nano powder, add 0.2 g of MgO, add alumina sol until the powder volume fraction is 55 vol%, and add 1% of ammonium polyacrylate as a dispersant to the prepared solution;

[0077] (2) Put the prepared slurry into a ball mill, set the rotation speed of the ball mill at 400 rpm, and mill for 2 h to fully stir and homogenize the slurry.

[0078] (3) Lay the degummed Al2O3 fiber cloth flat, evenly apply the prepared slurry on both sides of the degummed fiber cloth and stack them. Evenly apply silicone grease on the inner side of the PTFE film close to the fiber cloth, wrap the stacked fiber cloth, place a glass with a fixed shape on the PTFE film, place a layer of breathable felt on the upper glass, place a vacuum chuck and a suction nozzle on the breathable felt. After placement, wrap the above structure with a vacuum bag and seal it with a sealing machine. Connect the vacuum suction nozzle to a vacuum pump.

[0079] (4) Start the vacuum pump, put the vacuum bag into an oven, and cure at 160 °C for 2 h.

[0080] (5) Heat-treat the cured laminated specimen, and heat-treat at 1200 °C for 2 h in an argon atmosphere.

[0081] Example 5

[0082] This example provides a method for preparing an alumina fiber-reinforced oxide matrix composite material. The specific process is as follows:

[0083] (1) Take 30 g of Al2O3 nano-powder, 15 g of ZrO2-8Y nano-powder, add 0.2 g of MgO, add alumina sol until the powder volume fraction is 55 vol%, and add 1% of ammonium polyacrylate as a dispersant to the prepared solution.

[0084] (2) Put the prepared slurry into a ball mill, set the rotation speed of the ball mill at 300 rpm, and mill for 2 h to fully stir and homogenize the slurry.

[0085] (3) Lay the degummed Al2O3 fiber cloth flat, evenly apply the prepared slurry on both sides of the degummed fiber cloth and stack them. Evenly apply silicone grease on the inner side of the PTFE film close to the fiber cloth, wrap the stacked fiber cloth, place a glass with a fixed shape on the PTFE film, place a layer of breathable felt on the upper glass, place a vacuum chuck and a suction nozzle on the breathable felt. After placement, wrap the above structure with a vacuum bag and seal it with a sealing machine. Connect the vacuum suction nozzle to a vacuum pump.

[0086] (4) Start the vacuum pump, put the vacuum bag into an oven, and cure at 160 °C for 2 h.

[0087] (5) Heat-treat the cured laminated specimen, and heat-treat at 1200 °C for 2 h in an argon atmosphere.

[0088] Example 6

[0089] This embodiment provides a method for preparing an alumina fiber-reinforced oxide matrix composite material. The specific process is as follows:

[0090] (1) Take 30 g of Al2O3 nano-powder, 20 g of ZrO2-8Y nano-powder, add 0.05 g of MgO, add alumina sol until the powder volume fraction is 55 vol%, and add 1% of ammonium polyacrylate as a dispersant to the prepared solution;

[0091] (2) Put the prepared slurry into a ball mill, the rotation speed of the ball mill is 500 rpm, and ball mill for 4 h to fully stir the slurry evenly;

[0092] (3) Lay the degummed Al2O3 fiber cloth flat, evenly apply the prepared slurry on both sides of the degummed fiber cloth and stack them. Evenly apply silicone grease on the inner side of the PTFE film close to the fiber cloth, wrap the stacked fiber cloth, place a glass with a fixed shape on the PTFE film, place a layer of breathable felt on the upper glass, place a vacuum chuck and a suction nozzle on the breathable felt. After placing, wrap the above structure with a vacuum bag and seal it with a sealer. Connect the vacuum suction nozzle to a vacuum pump;

[0093] (4) Start the vacuum pump, put the vacuum bag into an oven, and cure at 160 °C for 2 h;

[0094] (5) Heat-treat the cured laminated specimen, and heat-treat at 1200 °C for 2 h in an argon atmosphere.

[0095] Example 7

[0096] This embodiment provides a method for preparing an alumina fiber-reinforced oxide matrix composite material. The specific process is as follows:

[0097] (1) Take 42 g of TiO2 nano-powder, 7 g of Nb2O5 nano-powder, add 0.049 g of MgO, add alumina sol until the powder volume fraction is 50 vol%, and add 0.1% of ammonium polyacrylate as a dispersant to the prepared solution;

[0098] (2) Put the prepared slurry into a ball mill, the rotation speed of the ball mill is 300 rpm, and ball mill for 2 h to fully stir the slurry evenly;

[0099] (3) Lay the degummed Al2O3 fiber cloth flat, evenly apply the prepared slurry on both sides of the degummed fiber cloth and stack them. Evenly apply silicone grease on the inner side of the PTFE film close to the fiber cloth, wrap the stacked fiber cloth, place a glass with a fixed shape on the PTFE film, place a layer of breathable felt on the upper glass, place a vacuum chuck and a suction nozzle on the breathable felt. After placing, wrap the above structure with a vacuum bag and seal it with a sealer. Connect the vacuum suction nozzle to a vacuum pump;

[0100] (4) Start the vacuum pump, put the vacuum bag into the oven, and cure it at 160 °C for 2 h;

[0101] (5) Heat-treat the cured laminated specimen, and heat-treat it at 1200 °C for 2 h under an argon atmosphere.

[0102] Example 8

[0103] This example provides a method for preparing an alumina fiber-reinforced oxide matrix composite material. The specific process is as follows:

[0104] (1) Take 40 g of TiO2 nano-powder and 7.3 g of Nb2O5 nano-powder, add 0.05 g of MgO, add alumina sol until the powder volume fraction is 565 vol%, and add 1% ammonium polyacrylate as a dispersant to the prepared solution;

[0105] (2) Put the prepared slurry into a ball mill, the rotation speed of the ball mill is 300 rpm, and ball mill for 2 h to make the slurry fully stirred and uniform;

[0106] (3) Lay the degummed Al2O3 fiber cloth flat, evenly apply the prepared slurry on both sides of the degummed fiber cloth and stack them. Evenly apply silicone grease on the inner side of the PTFE film close to the fiber cloth, wrap the stacked fiber cloth, place a glass with a fixed shape on the PTFE film, place a layer of breathable felt on the upper glass, place a vacuum suction cup and a suction nozzle on the breathable felt. After placing, wrap the above structure with a vacuum bag and seal it with a sealing machine. Connect the vacuum suction nozzle to the vacuum pump;

[0107] (4) Start the vacuum pump, put the vacuum bag into the oven, and cure it at 160 °C for 2 h;

[0108] (5) Heat-treat the cured laminated specimen, and heat-treat it at 1200 °C for 2 h under an argon atmosphere.

[0109] The above content is only to illustrate the technical idea of the present invention, and the protection scope of the present invention cannot be limited thereby. Any modification made on the basis of the technical solution according to the technical idea proposed by the present invention falls within the protection scope of the claims of the present invention.

Claims

1. A preparation method of an alumina fiber reinforced oxide matrix composite material, characterized in that It includes the following steps: Add MgO powder as a sintering aid to the oxide nano-powder, then add alumina sol to obtain a solution, add ammonium polyacrylate as a dispersant to the solution, obtain a slurry and stir it evenly; Lay the degummed Al2O3 fiber cloth flat, evenly apply the slurry on both sides of the degummed Al2O3 fiber cloth and stack several layers of degummed Al2O3 fiber cloth to obtain a fiber cloth stack; Wrap a release cloth outside the fiber cloth stack, apply silicone grease on the side of the release cloth close to the fiber cloth stack, place glass on the upper and lower parts of the release cloth respectively, place a breathable felt on the upper glass, and then place the whole in a vacuum bag. After sealing the vacuum bag, evacuate and cure, and then perform heat treatment to obtain an alumina fiber reinforced oxide matrix composite material.

2. The preparation method of the alumina fiber reinforced oxide matrix composite material according to claim 1, characterized in that, The oxide nano-powder is Al2O3 nano-powder and ZrO2-8Y nano-powder with a mass ratio of 1.5-2:1, pure Al2O3 nano-powder, or TiO2 nano-powder and Nb2O5 nano-powder with a mass ratio of 5.5-6:

1.

3. The preparation method of the alumina fiber reinforced oxide matrix composite material according to claim 1, characterized in that, The particle size of the oxide nano-powder is not greater than 500 nm.

4. The preparation method of the alumina fiber reinforced oxide matrix composite material according to claim 1, characterized in that, The MgO powder is 0.1%-0.5% of the mass of the oxide nano-powder.

5. The preparation method of the alumina fiber reinforced oxide matrix composite material according to claim 1, wherein, The volume fraction of the oxide nano-powder and MgO powder in the solution is 50-55 vol%.

6. The preparation method of the alumina fiber reinforced oxide matrix composite material according to claim 1, characterized in that, The solid content of the alumina sol is not less than 20%, the average particle size is not greater than 20 nm, the viscosity is not greater than 50 mPa·s, and the pH value is 3.5-4.

0.

7. The preparation method of the alumina fiber reinforced oxide matrix composite material according to claim 1, wherein, The mass of the ammonium polyacrylate is 0.1-1% of the total mass of the oxide nano-powder and MgO powder.

8. The preparation method of the alumina fiber reinforced oxide matrix composite material according to claim 1, characterized in that, The release cloth is a polytetrafluoroethylene dispersion resin film.

9. The preparation method of the alumina fiber reinforced oxide matrix composite material according to claim 1, wherein, The curing is carried out in an oven, the curing temperature is 160 °C, and the curing time is 2 h; The heat treatment is carried out in an air or argon gas atmosphere, the heat treatment temperature is 1000-1200 °C, and the heat treatment time is 2 h.

10. An alumina fiber reinforced oxide matrix composite material prepared by the preparation method of the alumina fiber reinforced oxide matrix composite material according to any one of claims 1 to 9.

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