CN115140714A - Si 3 N 4 Aerogel and preparation method thereof - Google Patents
Si 3 N 4 Aerogel and preparation method thereof Download PDFInfo
- Publication number
- CN115140714A CN115140714A CN202210636071.5A CN202210636071A CN115140714A CN 115140714 A CN115140714 A CN 115140714A CN 202210636071 A CN202210636071 A CN 202210636071A CN 115140714 A CN115140714 A CN 115140714A
- Authority
- CN
- China
- Prior art keywords
- aerogel
- drying
- reaction kettle
- preparation
- precursor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B21/00—Nitrogen; Compounds thereof
- C01B21/06—Binary compounds of nitrogen with metals, with silicon, or with boron, or with carbon, i.e. nitrides; Compounds of nitrogen with more than one metal, silicon or boron
- C01B21/068—Binary compounds of nitrogen with metals, with silicon, or with boron, or with carbon, i.e. nitrides; Compounds of nitrogen with more than one metal, silicon or boron with silicon
Abstract
The invention provides Si 3 N 4 An aerogel and a preparation method thereof, relating to the technical field of aerogel materials, wherein the Si is 3 N 4 The preparation method of the aerogel comprises the following steps: placing n-butyl ether solution containing perhydropolysilazane in an inert atmosphere in a high-pressure reaction kettle, and carrying out constant-temperature heat treatment on the high-pressure reaction kettle to obtain precursor wet gel; after the temperature of the high-pressure reaction kettle is reduced to room temperature, opening the high-pressure reaction kettle under the protection of the inert atmosphere, and drying the precursor wet gel to obtain a precursor dry gel; cracking the precursor xerogel to obtain Si 3 N 4 An aerogel. Compared with the prior art, the Si of the invention 3 N 4 The aerogel has the advantages of simple preparation process, high porosity, uniform pore channels, high specific surface area, excellent heat insulation performance, excellent high-temperature oxidation resistance and the like, and can be applied to antenna housing materials.
Description
Technical Field
The invention relates to the technical field of aerogel materials, in particular to Si 3 N 4 A preparation method of aerogel.
Background
With the rapid development of aerospace technologies, particularly with the continuous updating of hypersonic aircrafts, the mach number of the aircrafts is increasingly larger, and the radome can generate aerodynamic heat under the severe compression and friction of air, so that the radome needs to bear stronger heat flow impact and higher temperature. Porous silicon nitride ceramics are widely applied to antenna housing materials at present, but the pore diameter of the pores of the ceramics is mostly in the micron level and is far larger than the mean free path of air, so that the heat flow transmission is difficult to block, and the thermal conductivity of the ceramics is higher. Therefore, the key to solving the heat insulation problem of the antenna housing is to impregnate aerogel into the porous silicon nitride ceramic.
In the prior art, siO 2 The high temperature induced crystallization characteristics of aerogel materials themselves, as the earliest invented aerogel materials, limited their application in high temperature applications. ZrO (zirconium oxide) 2 ，Al2O 3 ，TiO 2 The metal oxide aerogel still has the problems of inevitable sintering and collapse of a pore structure in a high-temperature environment, and meanwhile, the metal oxides have high dielectric constants and do not have a wave-transmitting function. The low-oxide or non-oxide aerogel with better temperature resistance, such as SiC, siOC, siCN and the like, has higher dielectric loss, and is difficult to be applied to the antenna housing material. Si 3 N 4 The aerogel is synthesized by adopting urea-assisted sol-gel technology, and carbon is introduced in the process through multiple processes such as supercritical drying, carbonization, carbon thermal reduction, carbon combustion and the like, has large influence on the dielectric property of the material, and is also not suitable for being applied to antenna housing materials.
Disclosure of Invention
The invention solves the problems that the existing aerogel material or the aerogel material prepared by the existing method can not give consideration to both heat insulation and wave transmission performance and can not be applied to the antenna housing.
In order to solve the above problems, the present invention provides Si 3 N 4 The preparation method of the aerogel comprises the following steps:
step S1, placing an n-butyl ether solution containing perhydropolysilazane in a high-pressure reaction kettle under an inert atmosphere, and carrying out constant-temperature heat treatment on the high-pressure reaction kettle to obtain precursor wet gel;
s2, after the temperature of the high-pressure reaction kettle is reduced to room temperature, opening the high-pressure reaction kettle under the protection of the inert atmosphere, and drying the precursor wet gel to obtain a precursor dry gel;
s3, cracking the precursor xerogel to obtain Si 3 N 4 An aerogel.
Optionally, in step S1 or step S2, the inert atmosphere comprises one of a nitrogen, argon and carbon dioxide atmosphere.
Optionally, in step S1, the performing constant-temperature heat treatment on the autoclave includes: and (3) placing the high-pressure reaction kettle in a constant-temperature drying box at 160-230 ℃ and preserving heat for 2-8h.
Optionally, in step S1, in the n-butyl ether solution containing perhydropolysilazane, the perhydropolysilazane accounts for 10-20% of the mass fraction of the n-butyl ether solution.
Optionally, in step S2, the drying manner includes: drying under normal pressure, freeze drying or supercritical drying.
Optionally, the method of drying at atmospheric pressure comprises: and drying the precursor wet gel for 5-7d under the inert atmosphere at normal temperature.
Optionally, the method of freeze-drying comprises: and taking out the precursor wet gel from the high-pressure reaction kettle, replacing the precursor wet gel in cyclohexane for 3-5 days, taking out again, and freeze-drying at the temperature of-40 to-50 ℃.
Optionally, the supercritical drying method comprises: and taking out the precursor wet gel from the high-pressure reaction kettle, replacing the precursor wet gel in absolute ethyl alcohol for 3-5 days, then taking out again, and drying in a carbon dioxide supercritical medium at 8-10MPa and 45-52 ℃.
Optionally, in step S3, the cracking manner includes: nitrogen is used as cracking atmosphere, the temperature is raised to 900-1100 ℃ at the temperature raising rate of 1-5 ℃/min, and then the temperature is maintained for 2-4 hours.
Si according to the invention 3 N 4 Compared with the prior art, the preparation method of the aerogel has the advantages that the n-butyl ether solution of perhydropolysilazane is directly utilized to carry out high-temperature gelation in a high-pressure reaction kettle, a general drying method for preparing the aerogel is adopted, the aerogel material is prepared after high-temperature cracking, no carbon is involved in the whole preparation process, the dielectric loss is reduced to the maximum extent, and the aerogel has the advantages of simple preparation process, high porosity, uniform pore channel, high specific surface area, excellent heat-insulating property, excellent high-temperature oxidation resistance and the like, and can be applied to an antenna housing material.
In order to solve the technical problems, the invention also provides Si 3 N 4 Aerogel of Si according to 3 N 4 Preparation method of aerogel, and Si 3 N 4 The aerogel is used for preparing the antenna housing material.
Si according to the invention 3 N 4 Aerogel and said Si 3 N 4 The advantages of the aerogel preparation method over the prior art are the same and are not described herein again.
Drawings
FIG. 1 shows Si in an example of the present invention 3 N 4 A flow diagram of a method of making an aerogel;
FIG. 2 shows Si in example of the present invention 3 N 4 Nitrogen adsorption curve after high-temperature cracking of aerogel;
FIG. 3 shows Si in an example of the present invention 3 N 4 Pore size distribution curve after pyrolysis of aerogel;
FIG. 4 shows Si in an example of the present invention 3 N 4 Nitrogen adsorption curve of the aerogel calcined in the air;
FIG. 5 shows Si in an example of the present invention 3 N 4 Pore size distribution curve of aerogel calcined in air.
Detailed Description
The technical solutions in the embodiments of the present application will be described in detail and clearly with reference to the accompanying drawings.
The description of the term "some embodiments" means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. Throughout this specification, the schematic representations of the terms used above do not necessarily refer to the same implementation or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
As shown in FIG. 1, an embodiment of the present invention provides Si 3 N 4 The preparation method of the aerogel comprises the following steps:
step S1, placing an n-butyl ether solution containing perhydropolysilazane in a high-pressure reaction kettle under an inert atmosphere, and carrying out constant-temperature heat treatment on the high-pressure reaction kettle to obtain precursor wet gel;
s2, after the temperature of the high-pressure reaction kettle is reduced to room temperature, opening the reaction kettle under the protection of the inert atmosphere, and drying the precursor wet gel to obtain a precursor dry gel;
s3, cracking the precursor xerogel to obtain Si 3 N 4 An aerogel.
It should be noted that, in the high-pressure reaction kettle in this embodiment, the lining is made of polyparaphenylene, which has good high temperature resistance and corrosion resistance. In addition, in the embodiment, the n-butyl ether solution with low surface tension and no active group is selected as the solvent of the precursor sol, so that the subsequent drying process is facilitated, the drying shrinkage is reduced, and the specific surface area is increased.
Preferably, in step S1 or step S2, the inert atmosphere comprises one of a nitrogen, argon or carbon dioxide atmosphere. The inert atmosphere is involved to avoid oxidation of the aerogel.
In some embodiments, in step S1, the isothermal heat treatment of the autoclave includes: and (3) placing the high-pressure reaction kettle in a constant-temperature drying box at 160-230 ℃ for heat preservation for 2-8h. Therefore, the reaction is complete, and the sol-gel effect is good.
Preferably, in step S1, the perhydropolysilazane-containing n-butyl ether solution isThe perhydropolysilazane accounts for 10-20% of the mass fraction of the n-butyl ether solution. Thus, after the solvent in the gel is volatilized, si can be ensured 3 N 4 The aerogel possesses sufficient porosity.
In some embodiments, in step S2, the drying manner includes: drying under normal pressure, freeze drying or supercritical drying.
Specifically, the method for drying under normal pressure comprises the following steps: and drying the precursor wet gel for 5-7d under the inert atmosphere at normal temperature. The method is simple.
Specifically, the freeze-drying method comprises the following steps: and taking out the precursor wet gel from the high-pressure reaction kettle, replacing the precursor wet gel in cyclohexane for 3-5 days, then taking out the precursor wet gel again, and carrying out freeze drying at the temperature of-40 to-50 ℃.
It should be noted that in this embodiment, in the replacement process of cyclohexane, cyclohexane needs to be replaced every 12 hours, and the replacement effect is better because the freezing point of cyclohexane is higher and the surface tension is lower.
Specifically, the supercritical drying method comprises the following steps: and taking out the precursor wet gel from the high-pressure reaction kettle, replacing the precursor wet gel in absolute ethyl alcohol for 3-5 days, then taking out again, and drying in a carbon dioxide supercritical medium at 8-10MPa and 45-52 ℃.
It should be noted that, in the present embodiment, in the replacement process of anhydrous ethanol, the anhydrous ethanol needs to be replaced every 12 hours, so that the replacement effect is better, and the cost of the anhydrous ethanol is low.
In some preferred embodiments, in step S3, the cleavage comprises: nitrogen is used as cracking atmosphere, the temperature is raised to 900-1100 ℃ at the temperature raising rate of 1-5 ℃/min, and then the temperature is maintained for 2-4 hours.
In the embodiment, the cracking is carried out in a tubular furnace, and the furnace type has a simple structure, is easy to operate and is convenient to control.
Si prepared in this example, as shown in FIGS. 2 to 5 3 N 4 The aerogel has porosity of 85-95%, thermal conductivity less than 0.1W/(m.K), dielectric constant of 1.2-1.6, and dielectric loss tangent of 1.2 × 10 -3 -6.4×10 -3 The xerogel has a specific surface area as high as 404.28m 2 The specific surface area of the material is as high as 278.61m respectively after the material is subjected to pyrolysis at 600 ℃ and 1000 ℃ in nitrogen atmosphere 2 /g and 201.09m 2 The cracked aerogel is calcined in the air atmosphere of 600 ℃ and 1000 ℃ for oxidation resistance test, and the specific surface area is still as high as 197.99m respectively 2 G and 106.73m 2 (ii) in terms of/g. The preparation method has the advantages of simple preparation process, high porosity, uniform pore channels, high specific surface area, excellent heat insulation performance, excellent high-temperature oxidation resistance and the like, and can be applied to antenna housing materials.
Another embodiment of the present invention provides Si 3 N 4 Aerogel of and Si 3 N 4 The aerogel is used for preparing the antenna housing material.
Si described in the present example 3 N 4 Aerogel and said Si 3 N 4 The advantages of the aerogel preparation method over the prior art are the same and are not described herein again.
Example 1
This example provides Si 3 N 4 The preparation method of the aerogel comprises the following steps:
the method comprises the following steps: firstly, placing an n-butyl ether solution of perhydropolysilazane with the mass fraction of 20% in a high-pressure reaction kettle with a p-polyphenyl lining under the inert atmosphere, putting the reaction kettle into a thermostat with the temperature of 200 ℃ and preserving the heat for 2 hours to obtain precursor wet gel, and opening the high-pressure reaction kettle under the protection of the inert atmosphere when the temperature is reduced to the normal temperature;
step two: drying the precursor wet gel at normal pressure to obtain a precursor dry gel;
step three: cracking the precursor xerogel in a tube furnace to obtain Si 3 N 4 An aerogel material.
In this example, the inert atmosphere refers to nitrogen.
In this example, the drying of the precursor wet gel under normal pressure is directly performed for 6 days under an inert atmosphere at normal temperature.
In the embodiment, the cracking atmosphere is nitrogen, the temperature is 1000 ℃, the heating rate is 2 ℃/min, the heat preservation time is 2 hours, and the product is cooled along with the furnace.
Example 2
The present embodiment provides Si 3 N 4 The preparation method of the aerogel comprises the following steps:
the method comprises the following steps: firstly, placing a 10% n-butyl ether solution of perhydropolysilazane in an autoclave with a lining of polyparaphenylene under inert atmosphere, putting the autoclave in a thermostat at 220 ℃ and preserving heat for 3 hours to obtain precursor wet gel, cooling to normal temperature, and opening the autoclave under the protection of inert atmosphere;
step two: freeze-drying the precursor wet gel to obtain a precursor dry gel;
step three: cracking the precursor xerogel in a tube furnace to obtain Si 3 N 4 An aerogel material.
In this example, the inert gas atmosphere refers to argon.
In this example, the precursor wet gel was freeze-dried by taking it out, replacing it with cyclohexane for 4d, replacing cyclohexane every 12 hours, taking it out, and freeze-drying it at-40 ℃.
In the embodiment, the cracking atmosphere is nitrogen, the temperature is 1000 ℃, the heating rate is 3 ℃/min, the heat preservation time is 2 hours, and the product is cooled along with the furnace.
Example 3
The present embodiment provides Si 3 N 4 The preparation method of the aerogel comprises the following steps:
the method comprises the following steps: firstly, placing a 15% n-butyl ether solution of perhydropolysilazane in an autoclave with a p-polyphenyl lining under inert atmosphere, putting the autoclave in a thermostat at 200 ℃ and preserving heat for 3 hours to obtain precursor wet gel, cooling to normal temperature, and opening the autoclave under the protection of inert atmosphere;
step two: performing supercritical drying on the precursor wet gel to obtain a precursor xerogel;
step three: cracking the precursor xerogel in a tube furnace to obtain Si 3 N 4 An aerogel material.
In this embodiment, the inert atmosphere refers to a carbon dioxide atmosphere.
In this example, the precursor wet gel was subjected to supercritical drying by taking it out, replacing it with absolute ethanol for 4d, replacing ethanol every 12 hours, taking it out, and drying it in a carbon dioxide supercritical medium of 9MPa and 48 ℃.
In the embodiment, the cracking atmosphere is nitrogen, the temperature is 1000 ℃, the heating rate is 1 ℃/min, the heat preservation time is 3 hours, and the product is cooled along with the furnace.
Although the present disclosure has been described above, the scope of the present disclosure is not limited thereto. Various changes and modifications may be effected therein by one of ordinary skill in the pertinent art without departing from the spirit and scope of the present disclosure, and these changes and modifications are intended to be within the scope of the present disclosure.
Claims (10)
1. Si 3 N 4 The preparation method of the aerogel is characterized by comprising the following steps:
step S1, placing an n-butyl ether solution containing perhydropolysilazane in a high-pressure reaction kettle under an inert atmosphere, and carrying out constant-temperature heat treatment on the high-pressure reaction kettle to obtain precursor wet gel;
s2, after the temperature of the high-pressure reaction kettle is reduced to room temperature, opening the high-pressure reaction kettle under the protection of the inert atmosphere, and drying the precursor wet gel to obtain a precursor dry gel;
s3, cracking the precursor xerogel to obtain Si 3 N 4 An aerogel.
2. Si according to claim 1 3 N 4 The preparation method of the aerogel is characterized in that in the step S1 or the step S2, the inert atmosphere comprises one of nitrogen, argon and carbon dioxide.
3. Si according to claim 1 3 N 4 The preparation method of the aerogel is characterized in that in the step S1, the high-pressure reaction kettle is subjected to constant-temperature heat treatmentThe method comprises the following steps: and (3) placing the high-pressure reaction kettle in a constant-temperature drying box at 160-230 ℃ for heat preservation for 2-8h.
4. Si according to claim 1 3 N 4 The preparation method of the aerogel is characterized in that in the step S1, in the n-butyl ether solution containing perhydropolysilazane, the perhydropolysilazane accounts for 10-20% of the mass fraction of the n-butyl ether solution.
5. Si according to claim 1 3 N 4 The preparation method of the aerogel is characterized in that in the step S2, the drying mode comprises the following steps: drying under normal pressure, freeze drying or supercritical drying.
6. Si according to claim 5 3 N 4 The preparation method of the aerogel is characterized in that the normal pressure drying method comprises the following steps: and drying the precursor wet gel for 5-7d under the inert atmosphere at normal temperature.
7. Si according to claim 5 3 N 4 A method for the preparation of aerogels, characterized in that said freeze-drying method comprises: and taking out the precursor wet gel from the high-pressure reaction kettle, replacing the precursor wet gel in cyclohexane for 3-5 days, then taking out the precursor wet gel again, and carrying out freeze drying at the temperature of-40 to-50 ℃.
8. Si according to claim 5 3 N 4 A method for preparing an aerogel, characterized in that said supercritical drying method comprises: and taking out the precursor wet gel from the high-pressure reaction kettle, replacing the precursor wet gel in absolute ethyl alcohol for 3-5 days, then taking out again, and drying in a carbon dioxide supercritical medium at 8-10MPa and 45-52 ℃.
9. The Si according to claim 1 3 N 4 The preparation method of the aerogel is characterized in that in the step S3, the cracking mode comprises the following steps: nitrogen is used as cracking atmosphere and 1-5 deg.CHeating to 900-1100 deg.c at the heating rate of/min, and maintaining for 2-4 hr.
10. Si 3 N 4 Aerogel, characterized by Si according to any of claims 1 to 9 3 N 4 Preparation method of aerogel, and Si 3 N 4 The aerogel is used for preparing the antenna housing material.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210636071.5A CN115140714A (en) | 2022-06-07 | 2022-06-07 | Si 3 N 4 Aerogel and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210636071.5A CN115140714A (en) | 2022-06-07 | 2022-06-07 | Si 3 N 4 Aerogel and preparation method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115140714A true CN115140714A (en) | 2022-10-04 |
Family
ID=83406978
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210636071.5A Pending CN115140714A (en) | 2022-06-07 | 2022-06-07 | Si 3 N 4 Aerogel and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115140714A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116161968A (en) * | 2023-03-10 | 2023-05-26 | 西安理工大学 | Preparation method and application of wave-transparent material with switchable intelligent switch |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4818611A (en) * | 1985-11-19 | 1989-04-04 | Tao Nenryo Kogyo K.K. | High-purity silicon nitride fibers |
| JPH0586200A (en) * | 1991-06-20 | 1993-04-06 | Tonen Corp | Thermosetting copolymer and its production |
| JPH05319959A (en) * | 1991-10-21 | 1993-12-03 | Tonen Corp | Production of high-density ceramic |
| US5494867A (en) * | 1991-09-24 | 1996-02-27 | Southwest Research Institute | Method for making fiber-reinforced silicon nitride composites |
| US20210087406A1 (en) * | 2018-02-21 | 2021-03-25 | Antonio Sanchez | Perhydropolysilazane compositions and methods for forming oxide films using same |
-
2022
- 2022-06-07 CN CN202210636071.5A patent/CN115140714A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4818611A (en) * | 1985-11-19 | 1989-04-04 | Tao Nenryo Kogyo K.K. | High-purity silicon nitride fibers |
| JPH0586200A (en) * | 1991-06-20 | 1993-04-06 | Tonen Corp | Thermosetting copolymer and its production |
| US5494867A (en) * | 1991-09-24 | 1996-02-27 | Southwest Research Institute | Method for making fiber-reinforced silicon nitride composites |
| JPH05319959A (en) * | 1991-10-21 | 1993-12-03 | Tonen Corp | Production of high-density ceramic |
| US20210087406A1 (en) * | 2018-02-21 | 2021-03-25 | Antonio Sanchez | Perhydropolysilazane compositions and methods for forming oxide films using same |
Non-Patent Citations (1)
| Title |
|---|
| ANDREA ZAMBOTTI等: "Synthesis and thermal evolution of polysilazane-derived SiCN(O) aerogels with variable C content stable at 1600◦C", 《CERAMICS INTERNATIONAL》, vol. 47, no. 6, pages 8035 - 8043, XP086498104, DOI: 10.1016/j.ceramint.2020.11.157 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116161968A (en) * | 2023-03-10 | 2023-05-26 | 西安理工大学 | Preparation method and application of wave-transparent material with switchable intelligent switch |
| CN116161968B (en) * | 2023-03-10 | 2024-02-20 | 西安理工大学 | Preparation method and application of wave-transparent material with switchable intelligent switch |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102503581B (en) | Long-term high-temperature oxidation-resistant multi-element composite ceramic coating for carbon/carbon composite material and preparation and application methods thereof | |
| CN109553395B (en) | Low-cost preparation method of ceramic aerogel | |
| CN115140714A (en) | Si 3 N 4 Aerogel and preparation method thereof | |
| CN110653136B (en) | Surface oxidation-resistant high-emissivity coating of porous fibrous carbon-based heat-insulating material and preparation method thereof | |
| CN113831103A (en) | Preparation method of high-temperature-resistant alumina-silica aerogel composite material | |
| CN110510617B (en) | Normal-pressure drying preparation method of large-size alumina-silica aerogel | |
| CN104193384A (en) | Zirconium oxide-based porous composite material and preparation method thereof | |
| CN114715896B (en) | Preparation method of silicon carbide nanotube aerogel | |
| CN111099907A (en) | High-performance ceramic with surface modified zirconia fiber compounded with rare earth lanthanum zirconate and preparation method thereof | |
| CN113321524B (en) | Preparation method of ultrahigh-temperature ceramic aerogel based on multi-cavity structural fibers | |
| CN113860875B (en) | Preparation method of in-situ synthesized silicon carbide nanowire network modified carbon/carbon composite material | |
| CN111099909B (en) | High-performance ceramic with surface modified polycrystalline mullite fiber compounded with rare earth lanthanum zirconate and preparation method thereof | |
| CN106242610A (en) | A kind of preparation method of SiOC ceramic aerogel | |
| CN111116209B (en) | Directional porous silicon nitride honeycomb ceramic and rapid preparation method thereof | |
| CN115611632B (en) | Preparation method of flexible high-temperature-resistant silicon carbide aerogel composite heat insulation material | |
| CN111099908B (en) | High-performance ceramic of carbon fiber composite rare earth lanthanum zirconate with surface coated with silicon oxide and preparation method thereof | |
| CN114874026B (en) | Preparation method of high-strength fiber composite zirconia foam ceramic | |
| CN114380612A (en) | Preparation method of low-loss high-oxidation-resistance silicon carbide fiber reinforced zirconia-zirconium tungstate ceramic composite material | |
| CN113860847A (en) | Al (aluminum)2O3-SiO2Preparation method of aerogel composite material | |
| CN112409012A (en) | Blocky titanium carbide-silicon carbide composite aerogel material and preparation method thereof | |
| Xing-Xiang et al. | Sintering characteristics of microfine zirconia powder | |
| CN115010510B (en) | Low-thermal-conductivity zirconium carbide coated zirconia ceramic foam material and preparation method thereof | |
| CN115806430B (en) | Low-dielectric-constant microwave ceramic and preparation method thereof | |
| CN113735615B (en) | Micro-nanofiber composite gadolinium zirconate porous ceramic and preparation method and application thereof | |
| CN108752008B (en) | Porous Si2N2O high-temperature-resistant wave-transparent ceramic and preparation method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |