A high porosity silicon carbide ceramic material, a preparation method and application thereof
By adjusting the raw material ratio and process parameters through the sol-gel method, high-porosity silicon carbide ceramic materials were prepared, overcoming the limitations of existing technologies in porosity and mechanical strength adjustment. This enabled the low-cost and high-efficiency preparation of porous silicon carbide ceramics, which can be applied to the rapid densification of C/SiC composite materials.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SDIC CERAMIC MATRIX COMPOSITES RES INST (XIAN) CO LTD
- Filing Date
- 2023-12-11
- Publication Date
- 2026-04-10
AI Technical Summary
Existing methods for adjusting the porosity and mechanical strength of porous silicon carbide ceramics have limitations and are costly to produce.
High-porosity silicon carbide ceramic materials were prepared by the sol-gel method. By adjusting the ratio and viscosity of raw materials such as tetraethyl orthosilicate, resorcinol, anhydrous sodium carbonate and deionized water, and combining water bath heat treatment and sintering process, porous silicon carbide ceramics with high porosity and uniform pore size distribution were prepared.
This technology enables low-cost, large-scale production of porous silicon carbide ceramic materials, shortens the preparation cycle, improves the densification efficiency of C/SiC composite materials, and reduces production costs.
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Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of ceramic materials, in particular to a high porosity silicon carbide ceramic material and a preparation method and application thereof. BACKGROUND
[0002] Silicon carbide ceramics are widely used in the fields of energy, electronics, semiconductors, ceramics and coatings due to their excellent high-temperature resistance, corrosion resistance, high elastic modulus and high thermal conductivity. Porous structure has the characteristics of light weight, high porosity and high specific surface area, and has important research and application value in many fields such as filtration separation, heat transfer sensing and sound absorbing materials.
[0003] At present, the most commonly used and mature method for preparing porous silicon carbide ceramics is the pore-forming agent method and the organic foam impregnation method. The pore-forming agent method can effectively control the porosity and pore morphology of the sample by changing the type and amount of the pore-forming agent, but the control of the porosity is limited. The organic foam impregnation method is only suitable for preparing relatively regular-shaped samples, and the porosity adjustment and mechanical strength adjustment of the porous silicon carbide ceramics prepared have certain limitations. SUMMARY
[0004] In order to solve the above technical problems, the purpose of the present application is to provide a high porosity silicon carbide ceramic material and a preparation method and application thereof, so as to solve the problems of limitation of porosity adjustment and mechanical strength adjustment of existing porous silicon carbide ceramics and high preparation cost.
[0005] The technical solution of the present application to solve the above technical problems is as follows:
[0006] A preparation method of a high porosity silicon carbide ceramic material, comprising the following steps:
[0007] (1) mixing tetraethyl orthosilicate with anhydrous ethanol, stirring to obtain solution 1;
[0008] (2) adding resorcinol to an aqueous formaldehyde solution, stirring, then adding anhydrous sodium carbonate, stirring again to obtain solution 2;
[0009] (3) mixing deionized water with anhydrous ethanol, adding glacial acetic acid to adjust the pH to obtain solution 3;
[0010] (4) mixing solution 1 and solution 2, stirring, then adding solution 3 and continuing to stir to obtain solution 4;
[0011] (5) the solution 4 obtained in step (4) is subjected to water bath and heat treatment to obtain a porous silicon carbide precursor, and finally sintered to obtain.
[0012] The present application has the advantages that: the porous silicon carbide ceramic material is prepared by the sol-gel method, the preparation process is simple, the raw material ratio in each solution is adjusted, the viscosity of the solution is changed, the porous structure is effectively adjusted, and the high-porosity silicon carbide ceramic material with high porosity and uniform pore size distribution is obtained.
[0013] Further, the volume ratio of the tetraethyl orthosilicate and the anhydrous ethanol in step (1) is 100-200:40-60, the stirring temperature is 20-30 DEG C, and the time is 10-20 min.
[0014] Preferably, the volume ratio of the tetraethyl orthosilicate and the anhydrous ethanol in step (1) is 150:50, the stirring temperature is 25 DEG C, and the time is 15 min.
[0015] Further, the mass ratio of the m-phenylenediamine, the formaldehyde aqueous solution and the anhydrous sodium carbonate in step (2) is 10-30:50-200:0.1-0.5, the stirring temperature is 20-30 DEG C, the time is 10-20 min, and the re-stirring temperature is 20-30 DEG C, the time is 10-20 min.
[0016] Preferably, the mass ratio of the m-phenylenediamine, the formaldehyde aqueous solution and the anhydrous sodium carbonate in step (2) is 20:120:0.3, the stirring temperature is 25 DEG C, and the time is 15 min.
[0017] Further, the volume ratio of the deionized water and the anhydrous ethanol in step (3) is 20-100:50-80, and the pH is adjusted to 3-4.
[0018] Preferably, the volume ratio of the deionized water and the anhydrous ethanol in step (3) is 60:65, and the pH is adjusted to 3.5.
[0019] Further, the mass volume ratio of the tetraethyl orthosilicate in step (1), the m-phenylenediamine in step (2) and the deionized water in step (3) is 100-200 mL:10-30 g:20-100 mL.
[0020] Preferably, the mass volume ratio of the tetraethyl orthosilicate in step (1), the m-phenylenediamine in step (2) and the deionized water in step (3) is 150 mL:20 g:60 mL.
[0021] Further, the mixing and stirring temperature in step (4) is 20-30 DEG C, the time is 10-20 min, and the continuous stirring temperature is 20-30 DEG C, the time is 50-60 min.
[0022] Preferably, the mixing and stirring temperature in step (4) is 25 DEG C, the time is 15 min, and the continuous stirring temperature is 25 DEG C, the time is 55 min.
[0023] The beneficial effect of the further technical solution is that the preparation process of each solution is simple, the processing efficiency is high, the preparation period of the high porosity silicon carbide ceramic can be effectively shortened, and the production cost is reduced.
[0024] Further, the temperature of the water bath in step (5) is 50-70 DEG C, and the time is 1-2h; the temperature of the heat treatment is 90-110 DEG C, and the time is 1.5-2.5h; the sintering condition is that sintering is carried out at 1100-1300 DEG C for 1-2h under vacuum, nitrogen or inert gas protection atmosphere.
[0025] Preferably, the temperature of the water bath in step (5) is 60 DEG C, and the time is 1.5h; the temperature of the heat treatment is 100 DEG C, and the time is 2h; the sintering condition is that sintering is carried out at 1300 DEG C for 2h under nitrogen atmosphere.
[0026] The beneficial effect of the further technical solution is that the high porosity silicon carbide ceramic material is prepared by the sol-gel method, the sintering temperature in the processing process is low, and the time is short, which can save energy on the one hand and effectively reduce the production cost of the high porosity silicon carbide ceramic material on the other hand.
[0027] A high porosity silicon carbide ceramic material is prepared by the preparation method.
[0028] The high porosity silicon carbide ceramic material is applied to the preparation of a ceramic matrix composite material.
[0029] The beneficial effect of the present application is that the prepared high porosity silicon carbide ceramic material is applied to the preparation of C / SiC composite material, which can realize the rapid densification of C / SiC composite material, shorten the preparation period of C / SiC composite material, and reduce the production cost of C / SiC composite material.
[0030] The present application has the following beneficial effects:
[0031] (1) The preparation process is simple, the porosity of the high porosity silicon carbide ceramic material can be effectively adjusted by adjusting the ratio of raw materials and the viscosity of the solution, the raw material cost is low, the requirement for processing conditions is low, the preparation period of the porous silicon carbide ceramic material can be shortened, and large-scale production of the porous silicon carbide ceramic is realized at low cost.
[0032] (2) The prepared high porosity silicon carbide ceramic material can be applied to the preparation of C / SiC composite material, which realizes the rapid densification of C / SiC composite material, shortens the preparation period of C / SiC composite material, and reduces the production cost of C / SiC composite material. BRIEF DESCRIPTION OF DRAWINGS
[0033] Figure 1 XRD pattern of the high porosity silicon carbide ceramic material prepared in Example 1;
[0034] Figure 2 SEM morphology of the high porosity silicon carbide ceramic material prepared in Example 1, wherein, (a) is the SEM morphology with a scale of 50 μm, and (b) is the SEM morphology with a scale of 20 μm;
[0035] Figure 3 SEM morphology of the silicon carbide material prepared in Comparative Example 1;
[0036] Figure 4 SEM morphology of the C / SiC ceramic matrix composite material into which the high porosity silicon carbide ceramic material prepared in Example 1 is introduced, wherein, (a) is the SEM morphology with a scale of 50 μm, and (b) is the SEM morphology with a scale of 20 μm. DETAILED DESCRIPTION
[0037] The principles and features of the present application are described below in conjunction with the accompanying drawings, and the examples are only used to explain the present application and are not intended to limit the scope of the present application. The specific conditions not mentioned in the examples are carried out according to the conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments not mentioned by the manufacturer are all conventional products that can be purchased on the market.
[0038] Example 1:
[0039] A method for preparing a high porosity silicon carbide ceramic material, comprising the following steps:
[0040] (1) Preparation of solution 1
[0041] 150 mL of tetraethyl orthosilicate was mixed with 50 mL of anhydrous ethanol, mechanically stirred at room temperature for 15 min, and solution 1 was prepared.
[0042] (2) Preparation of solution 2
[0043] 20 g of resorcinol was weighed into 120 g of aqueous formaldehyde solution (formaldehyde mass fraction of 37%), stirred at room temperature for 15 min, then 0.3 g of anhydrous sodium carbonate was added, and stirred at room temperature for another 15 min to prepare solution 2.
[0044] (3) Preparation of solution 3
[0045] 60 mL of deionized water was mixed with 65 mL of anhydrous ethanol, then glacial acetic acid was added to adjust the pH of the solution to 3.5, and solution 3 was prepared.
[0046] (4) Mix solution 1 with solution 2, stir for 15 min at room temperature, then add solution 3 to the mixed solution, continue to stir for 55 min at room temperature, and prepare solution 4, which is a porous silicon carbide precursor solution.
[0047] (5) Heat solution 4 to 60℃ in a water bath, and keep for 1.5 h, then stand for 1 h, and then place the standing product in a reaction kettle and keep at 100℃ for 2 h, and prepare a porous silicon carbide precursor.
[0048] (6) Place the porous silicon carbide precursor prepared in step (5) in a high-temperature furnace under a nitrogen protective atmosphere, and sinter at 1200℃ for 2 h, and prepare a high-porosity silicon carbide ceramic material.
[0049] Example 2:
[0050] A method for preparing a high-porosity silicon carbide ceramic material, comprising the following steps:
[0051] (1) Prepare solution 1
[0052] Mix 100 mL of tetraethyl orthosilicate with 40 mL of anhydrous ethanol, mechanically stir for 10 min at room temperature, and prepare solution 1.
[0053] (2) Prepare solution 2
[0054] Weigh 10 g of resorcinol into 50 g of aqueous formaldehyde solution (formaldehyde mass fraction is 37%), stir for 15 min at room temperature, then add 0.1 g of anhydrous sodium carbonate, and continue to stir for 10 min at room temperature, and prepare solution 2.
[0055] (3) Prepare solution 3
[0056] Mix 20 mL of deionized water with 50 mL of anhydrous ethanol, then add glacial acetic acid to adjust the pH of the solution to 3, and prepare solution 3.
[0057] (4) Mix solution 1 with solution 2, stir for 10 min at room temperature, then add solution 3 to the mixed solution, and continue to stir for 50 min at room temperature, and prepare solution 4, which is a porous silicon carbide precursor solution.
[0058] (5) Heat solution 4 to 50℃ in a water bath, and keep for 1 h, then stand for 1 h, and then place the standing product in a reaction kettle and keep at 90℃ for 2.5 h, and prepare a porous silicon carbide precursor.
[0059] (6) Place the porous silicon carbide precursor prepared in step (5) in a high-temperature furnace under a nitrogen protective atmosphere, and sinter at 1200℃ for 2 h, and prepare a high-porosity silicon carbide ceramic material.
[0060] Example 3:
[0061] A method for preparing a high porosity silicon carbide ceramic material, comprising the following steps:
[0062] (1) Preparation of solution 1
[0063] Mix 200 mL of tetraethyl orthosilicate with 60 mL of anhydrous ethanol, mechanically stir at room temperature for 20 min, and prepare solution 1.
[0064] (2) Preparation of solution 2
[0065] Weigh 30 g of resorcinol and add it to 200 g of aqueous formaldehyde solution (formaldehyde mass fraction is 37%), stir at room temperature for 20 min, then add 0.5 g of anhydrous sodium carbonate, continue to stir at room temperature for 20 min, and prepare solution 2.
[0066] (3) Preparation of solution 3
[0067] Mix 100 mL of deionized water with 80 mL of anhydrous ethanol, then add glacial acetic acid to adjust the pH of the solution to 4, and prepare solution 3.
[0068] (4) Mix solution 1 and solution 2, stir at room temperature for 20 min, then add solution 3 to the mixed solution, and continue to stir at room temperature for 60 min to prepare solution 4, which is a porous silicon carbide precursor solution.
[0069] (5) Heat solution 4 to 70°C in a water bath for 2 h, then let it stand for 1 h, and then place the product after standing in a reaction kettle at 110°C for 1.5 h to prepare a porous silicon carbide precursor.
[0070] (6) Place the porous silicon carbide precursor prepared in step (5) in a high-temperature furnace under a nitrogen protective atmosphere and sinter at 1300°C for 2 h to prepare a high-porosity silicon carbide ceramic material.
[0071] Comparative Example 1:
[0072] A method for preparing a silicon carbide ceramic material, comprising the following steps:
[0073] (1) Preparation of solution 1
[0074] Mix 150 mL of tetraethyl orthosilicate with 100 mL of anhydrous ethanol, mechanically stir at room temperature for 15 min, and prepare solution 1.
[0075] (2) Preparation of solution 2
[0076] Weigh 40 g of resorcinol and add it to 120 g of aqueous formaldehyde solution (formaldehyde mass fraction is 37%), stir at room temperature for 15 min, then add 1 g of anhydrous sodium carbonate, continue to stir at room temperature for 15 min, and prepare solution 2.
[0077] (3) Preparation of solution 3
[0078] After mixing 60 mL of deionized water with 100 mL of anhydrous ethanol, add glacial acetic acid to adjust the pH of the solution to 3.5 to prepare solution 3.
[0079] (4) Mix solution 1 with solution 2, stir at room temperature for 15 min, then add solution 3 to the mixed solution and continue to stir at room temperature for 55 min to prepare solution 4, which is a porous silicon carbide precursor solution.
[0080] (5) Heat solution 4 to 60℃ in a water bath for 1.5 h, then stand for 1 h, and then place the standing product in a reaction kettle and heat at 100℃ for 2 h to prepare a porous silicon carbide precursor.
[0081] (6) Sinter the porous silicon carbide precursor prepared in step (5) in a high-temperature furnace under a nitrogen protective atmosphere at 1200℃ for 2 h to prepare a silicon carbide ceramic material.
[0082] Test Example:
[0083] Take the high-porosity silicon carbide ceramic material prepared in Example 1 to perform X-ray diffraction experiments and surface SEM morphology observation.
[0084] (1) X-ray diffraction experiment
[0085] The XRD pattern of the high-porosity silicon carbide ceramic material prepared in Example 1 is shown in Figure 1 As can be seen from the figure, all the peaks of the high-porosity silicon carbide ceramic material are consistent with the peak shape of SiC (PDF #72-1625), indicating that the silicon carbide material is successfully synthesized.
[0086] (2) Surface SEM morphology observation
[0087] The surface SEM morphology of the high-porosity silicon carbide ceramic material prepared in Example 1 is shown in Figure 2 As can be seen from the figure, the silicon carbide material with a porous structure is successfully prepared. The material has a three-dimensional interconnected porous structure, the pore wall thickness is relatively uniform, and has a clear grainy feeling. The pores are large and uniformly distributed, with a pore size of about 15 μm. The high-porosity silicon carbide ceramic material prepared in the present application can finely divide the internal pore structure of the ceramic matrix composite, improve the subsequent liquid phase wetting dynamics of C / SiC, and make the matrix of the ceramic matrix composite more uniform and have better mechanical properties.
[0088] The surface SEM morphology of the silicon carbide ceramic material prepared in Comparative Example 1 is shown in Figure 3As shown in the figure, the silicon carbide ceramic surface of the comparative example 1 prepared outside the range of the raw material ratio described in the application does not have a pore structure, does not have a three-dimensional interconnected porous structure and a clear grain feeling, and presents a broken block structure, which is not conducive to the introduction into the ceramic matrix composite to finely divide the internal pore structure of the ceramic matrix composite, to make the matrix of the ceramic matrix composite more uniform and to improve the mechanical properties, etc.
[0089] The high-porosity silicon carbide ceramic material prepared in Example 1 is introduced into the carbon fiber preform by a precursor impregnation and pyrolysis (PIP) process to prepare a C / SiC ceramic matrix composite material. The specific preparation process is as follows: the carbon fiber preform is immersed in the porous silicon carbide precursor solution prepared in Example 1, pressure impregnated for 2h at a pressure of 8kPa, then taken out and solidified at 120℃ for 2h, and finally pyrolyzed at 1200℃ for 2h in a nitrogen atmosphere to prepare a C / SiC ceramic matrix composite material.
[0090] The surface morphology of the C / SiC ceramic matrix composite material is shown in Figure 4 .
[0091] As shown in the figure, the high-porosity silicon carbide ceramic material introduced in the C / SiC ceramic matrix composite material can effectively divide the internal macropore structure thereof, making the pore size distribution in the internal thereof more uniform; as shown in Figure 4 (b) of the figure, the internal of the high-porosity silicon carbide ceramic material introduced also presents a porous structure, and the pore size distribution is relatively uniform. The matrix of the C / SiC ceramic matrix composite material is SiC, and the traditional method for preparing SiC is chemical vapor infiltration (CVI), which has a long preparation period. By introducing the high-porosity silicon carbide ceramic material into the C / SiC ceramic matrix composite material through the PIP process, the preparation period is shortened by one third compared with the traditional CVI method, and the porous silicon carbide can effectively divide the pore structure of the C / SiC ceramic matrix composite material, improve the wetting dynamics of the subsequent liquid phase infiltration into the C / SiC, and is beneficial to the improvement of the performance of the ceramic matrix composite material.
[0092] The above only describes the preferred embodiments of the application, and is not intended to limit the application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the application shall be included in the protection scope of the application.
Claims
1. A method for preparing a high-porosity silicon carbide ceramic material, characterized in that, Includes the following steps: (1) Mix tetraethyl orthosilicate with anhydrous ethanol and stir to obtain solution 1; (2) Add resorcinol to formaldehyde aqueous solution, stir for the first time, then add anhydrous sodium carbonate, stir for the second time to obtain solution 2; (3) Mix deionized water and anhydrous ethanol, add glacial acetic acid to adjust the pH to 3-4, and obtain solution 3; (4) Mix solution 1 and solution 2 and stir, then add solution 3 and continue stirring to obtain solution 4; (5) The solution 4 obtained in step (4) is subjected to water bath and heat treatment to obtain a porous silicon carbide precursor, which is then sintered to obtain the final product. The sintering conditions in step (5) are: sintering at 1100-1300 °C for 1-2 h under a vacuum, nitrogen or inert gas protective atmosphere; In step (1), the volume ratio of tetraethyl orthosilicate to anhydrous ethanol is 100-200:40-60; In step (2), the mass ratio of hydroquinone, formaldehyde aqueous solution, and anhydrous sodium carbonate is 10-30:50-200:0.1-0.
5. In step (3), the volume ratio of deionized water to anhydrous ethanol is 20-100:50-80; The mass-to-volume ratio of tetraethyl orthosilicate in step (1), resorcinol in step (2), and deionized water in step (3) is 100-200 mL: 10-30 g: 20-100 mL.
2. The method for preparing high-porosity silicon carbide ceramic material according to claim 1, characterized in that, The stirring temperature in step (1) is 20-30 ℃ and the time is 10-20 min.
3. The method for preparing high-porosity silicon carbide ceramic material according to claim 1, characterized in that, In step (2), the temperature of the first stirring is 20-30 ℃ and the time is 10-20 min; the temperature of the second stirring is 20-30 ℃ and the time is 10-20 min.
4. The method for preparing high-porosity silicon carbide ceramic material according to claim 1, characterized in that, In step (4), the mixing temperature is 20-30 ℃ and the time is 10-20 min; the mixing temperature is 20-30 ℃ and the time is 50-60 min.
5. The method for preparing high-porosity silicon carbide ceramic material according to claim 1, characterized in that, In step (5), the water bath temperature is 50-70 ℃ and the time is 1-2 h; the heat treatment temperature is 90-110 ℃ and the time is 1.5-2.5 h.
6. A high-porosity silicon carbide ceramic material, characterized in that, It is prepared by the preparation method according to any one of claims 1-5.
7. The application of the high-porosity silicon carbide ceramic material according to claim 6 in the preparation of ceramic matrix composites.
Citation Information
Patent Citations
Preparation method for mesoporous silicon carbide material
CN102674354A