CN112225566B - Silicon nitride powder, preparation method and application thereof, and ceramic material - Google Patents
Silicon nitride powder, preparation method and application thereof, and ceramic material Download PDFInfo
- Publication number
- CN112225566B CN112225566B CN202011115646.6A CN202011115646A CN112225566B CN 112225566 B CN112225566 B CN 112225566B CN 202011115646 A CN202011115646 A CN 202011115646A CN 112225566 B CN112225566 B CN 112225566B
- Authority
- CN
- China
- Prior art keywords
- silicon nitride
- nitride powder
- silicon
- reaction
- carbon
- 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.)
- Active
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/515—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics
- C04B35/58—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on borides, nitrides, i.e. nitrides, oxynitrides, carbonitrides or oxycarbonitrides or silicides
- C04B35/584—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on borides, nitrides, i.e. nitrides, oxynitrides, carbonitrides or oxycarbonitrides or silicides based on silicon nitride
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/626—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B
Abstract
The invention relates to silicon nitride powder, a preparation method and application thereof and a ceramic material. According to the preparation method of the silicon nitride powder, ethyl silicate is used as a silicon source, ethyl silicate, an organic carbon source and water are mixed to obtain a uniform mixed solution, the mixed solution is subjected to hydrothermal reaction to obtain a carbon-silicon mixture, the obtained carbon-silicon mixture is subjected to reduction reaction in a nitrogen atmosphere, and finally, excessive impurity carbon is removed through calcination, so that the high-purity silicon nitride powder is obtained. The silicon nitride powder prepared by the preparation method is loose, high in purity and high in sintering activity.
Description
Technical Field
The invention relates to the technical field of ceramics, in particular to silicon nitride powder, a preparation method and application thereof and a ceramic material.
Background
Silicon nitride is an important ceramic raw material, and the silicon nitride ceramic prepared by sintering the silicon nitride powder has excellent performances such as good thermal stability, oxidation resistance, dimensional stability, electrical insulation, rapid cooling and heating resistance, microwave permeability and the like. The silicon nitride ceramics have wide application fields, can be used for manufacturing bearing balls, rollers, rolling ball seat rings, tools and dies, novel ceramic cutters, pump plungers, sealing glow plugs, radomes of missiles and airplanes, and is also applied to the fields of electronics, military affairs and nuclear industry.
At present, the preparation method of silicon nitride powder mainly comprises a direct nitriding method, a liquid phase reaction method, a self-propagating combustion synthesis method and a carbothermic method; the direct nitriding method adopts high-purity silicon powder to directly synthesize the silicon nitride powder through high-temperature reaction in a nitrogen atmosphere, and the method has a simple process, but has the defects of incomplete reaction, large particle size of a product, low purity and the like. The liquid phase reaction method firstly generates the silicon imine through the reaction of the silicon tetrachloride and the liquid ammonia at a lower temperature, and then the silicon imine is heated and decomposed into the silicon nitride. In the self-propagating combustion synthesis method, silicon powder is placed in high-pressure nitrogen, and is subjected to external heating ignition to quickly react to obtain silicon nitride powder. The carbothermic reduction method is to synthesize silicon nitride powder at high temperature in nitrogen atmosphere by mixing silicon dioxide and carbon powder, has low cost and simple equipment, and is suitable for large-scale production, but the method has the defects of difficult control of side reaction, low purity of the prepared silicon nitride powder and the like.
The purity, particle size and properties of the silicon nitride powder directly affect the properties of the prepared silicon nitride ceramic. Therefore, how to prepare the high-purity silicon nitride powder has important significance.
Disclosure of Invention
Based on the silicon nitride powder, the invention provides the silicon nitride powder with high purity and small particle size, the preparation method and the application thereof, and the ceramic material.
The technical scheme of the invention is as follows.
One aspect of the present invention provides a method for preparing silicon nitride powder, comprising the following steps;
mixing ethyl silicate, an organic carbon source and water to obtain a mixed solution;
carrying out hydrothermal reaction on the mixed solution to obtain a carbon-silicon mixture;
and (3) placing the carbon-silicon mixture in a nitrogen atmosphere for reduction reaction, and then calcining to obtain silicon nitride powder.
In some embodiments, the molar ratio of the silicon element in the ethyl silicate to the carbon element in the organic carbon source is 1 (2-10).
In some of these embodiments, the hydrothermal reaction conditions are: reacting for 6-24 h at the temperature of 120-200 ℃ and under 0.5-3 MPa; and/or
The reduction reaction conditions are as follows: reacting for 6-24 h at 1200-1400 ℃.
In some of the embodiments, the calcining step is carried out in an oxygen-containing atmosphere, the calcining temperature is 600-800 ℃, and the calcining time is 3-6 h.
In some embodiments, the total content of the ethyl silicate and the organic carbon source is 30wt% to 60wt% based on the mass of the mixed solution.
In some of these embodiments, the step of mixing the ethyl silicate, the organic carbon source, and the water employs a ball milling method.
In some of these embodiments, the organic carbon source is selected from at least one of sucrose, glucose, and starch.
Another aspect of the present invention provides a silicon nitride powder, which is prepared by any one of the above preparation methods.
The invention also provides application of the silicon nitride powder in preparation of ceramic materials.
Further, the invention also provides a ceramic material, which comprises the silicon nitride powder.
Advantageous effects
According to the preparation method of the silicon nitride powder, ethyl silicate is used as a silicon source, ethyl silicate, an organic carbon source and water are mixed to obtain a uniform mixed solution, the mixed solution is subjected to hydrothermal reaction to obtain a carbon-silicon mixture, the obtained carbon-silicon mixture is subjected to reduction reaction in a nitrogen atmosphere, and finally, excessive impurity carbon is removed through calcination, so that high-purity silicon nitride is obtained.
The method comprises the following steps of mixing ethyl silicate, an organic carbon source and water to obtain a uniform mixed solution, so that the ethyl silicate and the organic carbon source are uniformly mixed, hydrolyzing the ethyl silicate to generate nano silicon dioxide in a hydrothermal reaction process, meanwhile, carrying out hydrothermal dehydration on the organic carbon source to uniformly generate simple substance carbon, uniformly depositing the generated nano silicon dioxide on the surface of the generated simple substance carbon, and mixing the nano silicon dioxide and the simple substance carbon at a molecular level, so that the condition that the silicon dioxide and the simple substance carbon are not uniformly mixed to cause side reaction in a subsequent reduction reaction is avoided; furthermore, the nano silicon dioxide and the simple substance carbon prepared in the hydrothermal environment have high activity, so that the subsequent Van noise reduction can be smoothly carried out at a lower temperature, the side reaction caused by high temperature is further avoided, the purity of the silicon nitride powder is improved, the silicon nitride powder with high sintering activity can be obtained, and the prepared silicon nitride powder is loose.
The invention further provides the silicon nitride powder prepared by the preparation method of the silicon nitride powder, the silicon nitride powder is loose and has the purity of 99 percent or more, wherein the content of alpha-phase silicon nitride is more than 90 weight percent, the median D50 of the particle diameter is less than 3 microns, and the silicon nitride powder has high sintering activity.
When the silicon nitride powder is applied to preparing ceramic materials, the prepared ceramic materials are high in compactness and excellent in comprehensive performance.
Drawings
FIG. 1 is a photograph of a silicon nitride powder in example 1.
Detailed Description
In order that the invention may be more fully understood, a more particular description of the invention will now be rendered by reference to specific embodiments thereof that are illustrated in the appended drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.
The traditional preparation method of the silicon nitride powder has the defects of low purity of the silicon nitride powder, large particle size, complex preparation process, high cost and the like. However, the purity, particle size and particle size distribution of the silicon nitride powder directly affect whether qualified silicon nitride ceramic products can be produced, so how to provide a method for preparing silicon nitride powder with simple preparation process, low cost, high purity and high sintering activity is a technical problem that technicians in the field of silicon nitride want to overcome.
Based on the research experience of the technicians in the field of silicon nitride for many years, the technicians find that: the ethyl silicate is used as a silicon source, and the ethyl silicate, the organic carbon source and water are mixed so as to uniformly mix the ethyl silicate and the organic carbon source, and simultaneously, the reaction is carried out in a hydrothermal environment. In the hydrothermal reaction process, the ethyl silicate is hydrolyzed to generate the nano silicon dioxide, meanwhile, the organic carbon source is subjected to hydrothermal dehydration to generate the simple substance carbon, the generated nano silicon dioxide is uniformly precipitated on the surface of the generated simple substance carbon, and the condition that the side reaction is generated in the subsequent reduction reaction due to the nonuniform mixing of the silicon dioxide and the simple substance carbon is avoided. And further obtains the technical scheme of the application through a large number of experiments.
An embodiment of the present invention provides a method for preparing silicon nitride powder, including the following steps S10 to S30.
And S10, mixing ethyl silicate, an organic carbon source and water to obtain a mixed solution.
And S20, carrying out hydrothermal reaction on the mixed solution obtained in the step S10 to obtain a carbon-silicon mixture.
The ethyl silicate, the organic carbon source and the water are mixed to obtain a uniform mixed solution, so that the ethyl silicate and the organic carbon source are uniformly mixed and react in a hydrothermal environment. In the hydrothermal reaction process, the ethyl silicate is hydrolyzed to generate nano silicon dioxide, meanwhile, the organic carbon source is subjected to hydrothermal dehydration to generate elemental carbon, the generated nano silicon dioxide is uniformly precipitated on the surface of the generated elemental carbon, and the nano silicon dioxide and the elemental carbon are mixed at a molecular level, so that the condition that a side reaction is generated in a subsequent reduction reaction due to nonuniform mixing of the silicon dioxide and the elemental carbon is avoided; furthermore, the nano silicon dioxide and the simple substance carbon prepared in the hydrothermal environment have high activity, so that the subsequent reduction reaction can be smoothly carried out at a lower temperature, the side reaction caused by high temperature is further avoided, the purity of silicon nitride is improved, and the silicon nitride powder with high sintering activity can be obtained and is loose.
In some embodiments, in step S10, the molar ratio of the silicon element in the ethyl silicate to the carbon element in the organic carbon source is 1 (2-10).
In some embodiments, in step S10, the molar ratio of the silicon element in the ethyl silicate to the carbon element in the organic carbon source is 1 (3-10).
Preferably, in step S10, the molar ratio of the silicon element in the ethyl silicate to the carbon element in the organic carbon source is 1 (3-5).
In some embodiments, the total content of the ethyl silicate and the organic carbon source in step S10 is 30wt% to 60wt% based on the mass of the mixed solution.
The total content of the ethyl silicate and the organic carbon source is controlled to be 30-60 wt%, so that the ethyl silicate and the organic carbon source are mixed more uniformly, the nano silicon dioxide generated in the hydrothermal reaction process is uniformly precipitated on the surface of the generated simple substance carbon, and the ethyl silicate and the organic carbon source are mixed at a molecular level.
In some of these embodiments, in step S10, the organic carbon source is selected from at least one of sucrose, glucose, and starch.
In some embodiments, the step of mixing ethyl silicate, organic carbon source and water in step S10 is ball milling. The ethyl silicate and the organic carbon source can be further uniformly mixed by adopting a ball milling method.
When it is required to be noted that, in the step S10, the step of mixing the ethyl silicate, the organic carbon source and the water may adopt a mode of mixing the ethyl silicate, the organic carbon source and the water together, and the three have no specific adding sequence; or dissolving ethyl silicate and organic carbon source in water to obtain solution, and mixing the two solutions.
Further, in step 20, the hydrothermal reaction conditions are as follows: reacting for 6 to 24 hours at the temperature of between 120 and 200 ℃ and under the pressure of between 0.5 and 3 MPa.
Under the hydrothermal reaction condition, ethyl silicate is hydrolyzed to generate nano silicon dioxide, meanwhile, the organic carbon source is subjected to hydrothermal dehydration to generate homogeneous simple substance carbon, the generated nano silicon dioxide is uniformly precipitated on the surface of the generated simple substance carbon, the nano silicon dioxide and the simple substance carbon are mixed at a molecular level, the prepared nano silicon dioxide and the prepared simple substance carbon have high activity, the follow-up reduction reaction can be smoothly carried out at a lower temperature, the side reaction caused by high temperature is avoided, the purity of silicon nitride is improved, and therefore silicon nitride powder with high sintering activity can be obtained, and the prepared silicon nitride powder is loose.
In some embodiments, in step S20, after the hydrothermal reaction is completed, the method further includes a step of filtering and drying a product after the hydrothermal reaction to obtain a carbon-silicon mixture.
And S30, placing the carbon-silicon mixture obtained in the step S20 in a nitrogen atmosphere for reduction reaction, and then calcining to obtain silicon nitride powder.
In step S30, the carbon-silicon mixture is subjected to a reduction reaction under a nitrogen atmosphere, specifically, the following reaction occurs.
SiO 2 (s)+C(s)→SiO(g)+CO(g)；
3SiO(g)+2N 2 (g)+3CO(g)→Si 3 N 4 (s)+3CO 2 (g) Or;
3SiO(g)+2N 2 (g)+3C(s)→Si 3 N 4 (s)+3CO(g)。
in the carbon-silicon mixture obtained in step S20, the nanoscale silicon dioxide and the elemental carbon are mixed at a molecular level, so that a side reaction generated in the reduction reaction in step S30 due to uneven mixing of the silicon dioxide and the elemental carbon is avoided.
Further, in step S30, the conditions of the reduction reaction are: reacting for 6-24 h at 1200-1400 ℃.
In some embodiments, in step S30, the calcination step is performed in an oxygen-containing atmosphere, the calcination temperature is 600 ℃ to 800 ℃, and the calcination time is 3h to 6h.
Specifically, in step S30, the calcination step is performed in an air atmosphere.
And (3) removing redundant carbon in the product obtained by the reduction reaction through a calcination step, thereby obtaining high-purity silicon nitride powder which is loose.
One embodiment of the present invention provides a silicon nitride powder produced by any one of the above-described production methods.
In the preparation method, the ethyl silicate, the organic carbon source and the water are mixed to obtain a uniform mixed solution, so that the ethyl silicate and the organic carbon source are uniformly mixed and react in a hydrothermal environment. In the hydrothermal reaction process, the ethyl silicate is hydrolyzed to generate nano silicon dioxide, meanwhile, the organic carbon source water is subjected to thermal dehydration and homogeneous phase to generate simple substance carbon, the generated nano silicon dioxide is uniformly precipitated on the surface of the generated simple substance carbon, and the nano silicon dioxide and the simple substance carbon are mixed at a molecular level, so that the condition that a side reaction is generated in a subsequent reduction reaction due to nonuniform mixing of the silicon dioxide and the simple substance carbon is avoided; furthermore, the nano silicon dioxide and the simple substance carbon prepared in the hydrothermal environment have high activity, so that the reduction reaction can be smoothly carried out at a lower temperature, the side reaction caused by high temperature is further avoided, the purity of silicon nitride is improved, and the silicon nitride powder with high sintering activity can be obtained and is loose.
Specifically, the silicon nitride powder prepared by the preparation method is loose and has the purity of 99% or more, wherein the content of alpha-phase silicon nitride is more than 90wt%, and the median D50 of the particle size is less than 3 microns.
The invention also provides application of the silicon nitride powder in preparation of ceramic materials.
The silicon nitride powder prepared by the preparation method is loose and high in purity, has a small median D50 of particle size, and has high sintering activity. When the silicon nitride powder is applied to preparing a ceramic material, the compactness of the ceramic can be improved, and further the mechanical property, the thermal stability, the dielectric property and other properties of the ceramic material are improved, so that the ceramic material with excellent comprehensive properties is obtained.
Further, an embodiment of the present invention further provides a ceramic material, which includes the silicon nitride powder.
The silicon nitride powder is loose, high in purity, small in median D50 of particle size, high in sintering activity, and capable of improving compactness of a ceramic material, further improving mechanical properties, thermal stability, dielectric properties and other properties of the ceramic material, and the ceramic material with excellent comprehensive properties is obtained
DETAILED DESCRIPTION OF EMBODIMENT (S) OF INVENTION
The silicon nitride powder, the preparation method and the application thereof, and the ceramic material according to the present invention are exemplified herein, but the present invention is not limited to the following examples.
Example 1
1) Dissolving sucrose in pure water to prepare a solution, adding ethyl silicate, and uniformly stirring and mixing the solution by adopting a ball milling method to obtain a mixed solution. Wherein, the mol ratio of the silicon element in the ethyl silicate to the carbon element in the sucrose is 1:3.
2) Putting the mixed solution obtained in the step 1) into a high-pressure reaction kettle, and adding a proper amount of pure water into the high-pressure reaction kettle to ensure that the total content of the ethyl silicate and the sucrose in the mixed solution in the high-pressure reaction kettle is 50wt%, and the material filling degree in the reaction kettle is 70%. And then starting the high-pressure reaction kettle, keeping the pressure in the kettle at 1MPa and the temperature at 180 ℃, and carrying out heat preservation reaction for 12 hours. And after the reaction is finished, filtering the reaction product in the high-pressure reaction kettle, and drying a filter cake to obtain the carbon-silicon mixture.
3) Putting the carbon-silicon mixture obtained in the step 2) into a nitrogen reaction furnace, introducing nitrogen, heating, keeping the temperature at 1350 ℃ for 18 hours, and taking out a reaction product.
4) Calcining the reaction product obtained in the step 3) in an air atmosphere at 600-800 ℃ for 5 hours, and cooling to obtain silicon nitride powder.
5) And (3) testing: the purity of the silicon nitride powder obtained in the step 4) is tested, and the test result of the test method by reference to GB/T16555-2017 shows that: the silicon nitride content in the silicon nitride powder obtained in the step 4) is 99.2%, wherein the alpha-phase silicon nitride content is 93%, the particle size D50 is 1.8 microns, and the residual carbon content is 0.2%.
Example 2
1) Dissolving sucrose in pure water to prepare a solution, adding ethyl silicate, and uniformly stirring and mixing the solution by adopting a ball milling method to obtain a mixed solution. Wherein, the mol ratio of the silicon element in the ethyl silicate to the carbon element in the sucrose is 1:5.
2) Putting the mixed solution obtained in the step 1) into a high-pressure reaction kettle, and adding a proper amount of pure water into the high-pressure reaction kettle to ensure that the total content of the ethyl silicate and the sucrose in the mixed solution in the high-pressure reaction kettle is 50wt%, and the material filling degree in the reaction kettle is 70%. Then, the high-pressure reaction kettle is started, the pressure in the kettle is 1.5MPa, the temperature is 180 ℃, and the reaction is carried out for 12 hours under the condition of heat preservation. And after the reaction is finished, filtering the reaction product in the high-pressure reaction kettle, and drying a filter cake to obtain the carbon-silicon mixture.
3) Putting the carbon-silicon mixture obtained in the step 2) into a nitrogen reaction furnace, introducing nitrogen, heating, keeping the temperature at 1350 ℃ for 18 hours, and taking out a reaction product.
4) Calcining the reaction product obtained in the step 3) in an air atmosphere at 600-800 ℃ for 5 hours, and cooling to obtain silicon nitride powder.
5) And (3) testing: same as example 1, step 5), the test results show that: the silicon nitride content in the silicon nitride powder obtained in the step 4) is 99.2%, wherein the alpha-phase silicon nitride content is 93.5%, the particle size D50 is 2.0 microns, and the residual carbon content is 0.3%.
Example 3
1) Dissolving sucrose in pure water to prepare a solution, adding ethyl silicate, and uniformly stirring and mixing the solution by adopting a ball milling method to obtain a mixed solution. Wherein, the mol ratio of the silicon element in the ethyl silicate to the carbon element in the sucrose is 1:7.
2) Putting the mixed solution obtained in the step 1) into a high-pressure reaction kettle, and adding a proper amount of pure water into the high-pressure reaction kettle to ensure that the total content of the ethyl silicate and the sucrose in the mixed solution in the high-pressure reaction kettle is 60wt%, and the material filling degree in the reaction kettle is 70%. Then, the high-pressure reaction kettle is started, the pressure in the kettle is 2.0MPa, the temperature is 180 ℃, and the reaction is carried out for 12 hours under the condition of heat preservation. And after the reaction is finished, filtering the reaction product in the high-pressure reaction kettle, and drying a filter cake to obtain the carbon-silicon mixture.
3) Putting the carbon-silicon mixture obtained in the step 2) into a nitrogen reaction furnace, introducing nitrogen, heating, keeping the temperature at 1250 ℃, reacting for 18 hours, and taking out a reaction product.
4) Calcining the reaction product obtained in the step 3) in an air atmosphere at 600-800 ℃ for 5 hours, and cooling to obtain silicon nitride powder.
5) And (3) testing: same as example 1, step 5), the test results show that: the silicon nitride content in the silicon nitride powder obtained in the step 4) is 99.2%, wherein the alpha-phase silicon nitride content is 94%, the particle size D50 is 2.3 microns, and the residual carbon content is 0.3%.
Example 4
1) Dissolving sucrose in pure water to prepare a solution, adding ethyl silicate, and uniformly stirring and mixing the solution by adopting a ball milling method to obtain a mixed solution. Wherein, the mol ratio of silicon element in the ethyl silicate to carbon element in the sucrose is 1.
2) Putting the mixed solution obtained in the step 1) into a high-pressure reaction kettle, and adding a proper amount of pure water into the high-pressure reaction kettle to ensure that the total content of the ethyl silicate and the sucrose in the mixed solution in the high-pressure reaction kettle is 30wt%, and the material filling degree in the reaction kettle is 70%. Then, the high-pressure reaction kettle is started, the pressure in the kettle is 2.5MPa, the temperature is 180 ℃, and the reaction is carried out for 12 hours under the condition of heat preservation. And after the reaction is finished, filtering the reaction product in the high-pressure reaction kettle, and drying a filter cake to obtain the carbon-silicon mixture.
3) Putting the carbon-silicon mixture obtained in the step 2) into a nitrogen reaction furnace, introducing nitrogen, heating, keeping the temperature at 1350 ℃ for 18 hours, and taking out a reaction product.
4) Calcining the reaction product obtained in the step 3) in an air atmosphere at 600-800 ℃ for 5 hours, and cooling to obtain silicon nitride powder.
5) And (3) testing: same as example 1, step 5), the test results show that: the content of silicon nitride in the silicon nitride powder obtained in the step 4) is 99.0%, wherein the content of alpha-phase silicon nitride is 94.5%, the particle size D50 is 2.5 microns, and the residual carbon content is 0.3%.
Example 5
1) Dissolving sucrose in pure water to prepare a solution, adding ethyl silicate, and uniformly stirring and mixing the solution by adopting a ball milling method to obtain a mixed solution. Wherein, the mol ratio of silicon element in the ethyl silicate to carbon element in the sucrose is 1:2.
2) Putting the mixed solution obtained in the step 1) into a high-pressure reaction kettle, and adding a proper amount of pure water into the high-pressure reaction kettle to ensure that the total content of the ethyl silicate and the sucrose in the mixed solution in the high-pressure reaction kettle is 50wt%, and the material filling degree in the reaction kettle is 70%. And then starting the high-pressure reaction kettle, enabling the pressure in the kettle to be 3MPa and the temperature to be 180 ℃, and carrying out heat preservation reaction for 12 hours. And after the reaction is finished, filtering the reaction product in the high-pressure reaction kettle, and drying a filter cake to obtain the carbon-silicon mixture.
3) Putting the carbon-silicon mixture obtained in the step 2) into a nitrogen reaction furnace, introducing nitrogen, heating, keeping the temperature at 1350 ℃ for 18 hours, and taking out a reaction product.
4) Calcining the reaction product obtained in the step 3) in an air atmosphere at 600-800 ℃ for 5 hours, and cooling to obtain silicon nitride powder.
5) And (3) testing: same as example 1, step 5), the test results show that: the silicon nitride content in the silicon nitride powder obtained in the step 4) is 99.0%, wherein the alpha-phase silicon nitride content is 92%, the particle size D50 is 1.7 microns, and the residual carbon content is 0.2%.
Example 6
1) Dissolving sucrose in pure water to prepare a solution, adding ethyl silicate, and uniformly stirring and mixing the solution by adopting a ball milling method to obtain a mixed solution. Wherein, the mol ratio of the silicon element in the ethyl silicate to the carbon element in the sucrose is 1:3.
2) Putting the mixed solution obtained in the step 1) into a high-pressure reaction kettle, and adding a proper amount of pure water into the high-pressure reaction kettle to ensure that the total content of the ethyl silicate and the sucrose in the mixed solution in the high-pressure reaction kettle is 70wt%, and the material filling degree in the reaction kettle is 70%. And then starting the high-pressure reaction kettle, keeping the pressure in the kettle at 1MPa and the temperature at 180 ℃, and carrying out heat preservation reaction for 12 hours. And after the reaction is finished, filtering the reaction product in the high-pressure reaction kettle, and drying a filter cake to obtain the carbon-silicon mixture.
3) Putting the carbon-silicon mixture obtained in the step 2) into a nitrogen reaction furnace, introducing nitrogen, heating, keeping the temperature at 1350 ℃ for 18 hours, and taking out a reaction product.
4) Calcining the reaction product obtained in the step 3) in an air atmosphere at 600-800 ℃ for 5 hours, and cooling to obtain silicon nitride powder.
5) And (3) testing: same as example 1, step 5), the test results show that: the silicon nitride content in the silicon nitride powder obtained in the step 4) is 97.8%, wherein the alpha-phase silicon nitride content is 89%, the particle size D50 is 2.0 microns, and the residual carbon content is 0.8%.
Comparative example 1
1) And (3) carrying out carbonization reaction on the sucrose under an inert condition to obtain the carbon powder. Dissolving carbon powder in water, adding ethyl silicate, and uniformly stirring and mixing the solution by adopting a ball milling method to obtain a mixed solution. Wherein, the molar ratio of the silicon element in the ethyl silicate to the carbon element in the carbon powder is 1:3.
2) Putting the mixed solution obtained in the step 1) into a high-pressure reaction kettle, and adding a proper amount of pure water into the high-pressure reaction kettle to ensure that the total content of the ethyl silicate and the sucrose in the mixed solution in the high-pressure reaction kettle is 50wt%, and the material filling degree in the reaction kettle is 70%. And then starting the high-pressure reaction kettle, keeping the pressure in the kettle at 1MPa and the temperature at 180 ℃, and carrying out heat preservation reaction for 12 hours. And after the reaction is finished, filtering the reaction product in the high-pressure reaction kettle, and drying a filter cake to obtain the carbon-silicon mixture.
3) Putting the carbon-silicon mixture obtained in the step 2) into a nitrogen reaction furnace, introducing nitrogen, heating, keeping the temperature at 1350 ℃ for reacting for 18 hours, and taking out a reaction product.
4) Calcining the reaction product obtained in the step 3) in an air atmosphere at 600-800 ℃ for 5 hours, and cooling to obtain silicon nitride powder.
5) And (3) testing: same as example 1, step 5), the test results show that: the silicon nitride powder obtained in the step 4) contains 95% of silicon nitride, wherein the content of alpha-phase silicon nitride is 80%, the particle size D50 is 5.0 microns, and the residual carbon content is 3.8%.
The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above examples only show several embodiments of the present invention, and the description thereof is specific and detailed, but not to be construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.
Claims (10)
1. A preparation method of silicon nitride powder is characterized by comprising the following steps;
mixing ethyl silicate, an organic carbon source and water to obtain a mixed solution; wherein the organic carbon source is selected from at least one of sucrose, glucose and starch;
carrying out hydrothermal reaction on the mixed solution to obtain a carbon-silicon mixture; the conditions of the hydrothermal reaction are as follows: reacting for 6 to 24 hours at the temperature of between 120 and 200 ℃ and under the pressure of between 0.5 and 3 MPa;
and (3) placing the carbon-silicon mixture in a nitrogen atmosphere for reduction reaction, and then calcining to obtain silicon nitride powder.
2. The method according to claim 1, wherein the molar ratio of the silicon element in the ethyl silicate to the carbon element in the organic carbon source is 1 (2-10).
3. The method of claim 1, wherein the reduction reaction is carried out under conditions of: reacting for 6-24 h at 1200-1400 ℃.
4. The method according to claim 1, wherein the calcination step is carried out in an oxygen-containing atmosphere, the calcination temperature is 600 ℃ to 800 ℃, and the calcination time is 3h to 6h.
5. The method according to any one of claims 1 to 4, wherein the total content of the ethyl silicate and the organic carbon source is 30 to 60wt% based on the mass of the mixed solution.
6. The method according to any one of claims 1 to 4, wherein the step of mixing the ethyl silicate, the organic carbon source and the water employs a ball milling method.
7. The method according to any one of claims 1 to 4, wherein after the hydrothermal reaction is completed, the method further comprises the step of filtering and drying the product after the hydrothermal reaction to obtain a carbon-silicon mixture.
8. Silicon nitride powder, characterized in that it is produced by the method of any one of claims 1 to 7.
9. Use of silicon nitride powder according to claim 8 for the preparation of a ceramic material.
10. A ceramic material comprising the silicon nitride powder according to claim 8.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011115646.6A CN112225566B (en) | 2020-10-19 | 2020-10-19 | Silicon nitride powder, preparation method and application thereof, and ceramic material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011115646.6A CN112225566B (en) | 2020-10-19 | 2020-10-19 | Silicon nitride powder, preparation method and application thereof, and ceramic material |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112225566A CN112225566A (en) | 2021-01-15 |
| CN112225566B true CN112225566B (en) | 2023-01-31 |
Family
ID=74117967
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011115646.6A Active CN112225566B (en) | 2020-10-19 | 2020-10-19 | Silicon nitride powder, preparation method and application thereof, and ceramic material |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112225566B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113417069A (en) * | 2021-06-03 | 2021-09-21 | 南昌大学 | Method for preparing silicon cathode material based on electrostatic spinning technology and application thereof |
| CN114716252B (en) * | 2022-04-27 | 2023-05-09 | 中国科学院上海硅酸盐研究所 | Preparation method of easy-sintering high-purity silicon nitride powder |
| CN116902929A (en) * | 2023-08-16 | 2023-10-20 | 衡阳凯新特种材料科技有限公司 | Preparation method of high-purity silicon nitride powder |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101353160A (en) * | 2008-09-09 | 2009-01-28 | 辽宁工业大学 | Synthetic method of silicon nitride nanopowder |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111115592B (en) * | 2020-01-09 | 2021-08-20 | 北京科技大学 | Preparation method of nano silicon nitride powder |
-
2020
- 2020-10-19 CN CN202011115646.6A patent/CN112225566B/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101353160A (en) * | 2008-09-09 | 2009-01-28 | 辽宁工业大学 | Synthetic method of silicon nitride nanopowder |
Non-Patent Citations (3)
| Title |
|---|
| Sol–gel synthesis of Si3N4 nanowires and nanotubes;FengWang等;《Materials Letters》;20050913;第330-333页 * |
| 溶胶-凝胶碳热法制备超细Si3N4粉的研究;盛连根;《无机材料学报》;19931231;第483-487页 * |
| 纳米Si3N4粉末制备技术及研究;陈宏;《中国硕士学位论文全文数据库工程科技I辑》;20070815;第B020-83页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112225566A (en) | 2021-01-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN112225566B (en) | Silicon nitride powder, preparation method and application thereof, and ceramic material | |
| CN106810267B (en) | Preparation method of high-purity silicon nitride powder | |
| CN100453508C (en) | Chemically excited combustion process for synthesizing Si3N4/SiC composite powder | |
| CN108383530A (en) | A kind of ZrB2The presoma conversion method preparation process of SiC ceramic composite granule | |
| CN108793101A (en) | A kind of method that alumina carbon tropical resources reduction prepares aluminium nitride under vacuum | |
| JPS61151006A (en) | Production of aluminum nitride powder | |
| CN111115592B (en) | Preparation method of nano silicon nitride powder | |
| TW201213508A (en) | A method for producing β -SiAlON | |
| JP7027196B2 (en) | Manufacturing method of aluminum nitride powder | |
| JP6560796B2 (en) | Method for producing spherical silicon nitride powder | |
| CN108996483B (en) | Method for synthesizing silicon nitride powder by combustion | |
| CN110240132B (en) | Silicon-magnesium nitride powder based on molten salt method and preparation method thereof | |
| JPH0323206A (en) | Aluminum nitride powder and its production | |
| US10384941B2 (en) | Method for producing spherical silicon nitride powder | |
| CN103570359A (en) | Production process for submicron silicon nitride (Si3N4) ceramic powder | |
| US5585084A (en) | Silicon nitride powder | |
| CN114716252B (en) | Preparation method of easy-sintering high-purity silicon nitride powder | |
| JPS6355108A (en) | Aluminum nitride powder and production thereof | |
| CN100457684C (en) | Synthetic preparation method of A1N ceramic powder | |
| CN110981490A (en) | CNT toughening of B4C-SiC laminated composite ceramic and preparation method thereof | |
| CN113443611B (en) | Preparation method of nitride powder | |
| CN114409414B (en) | Method for preparing high-purity silicon nitride powder by taking high-oxygen-content silicon powder as raw material | |
| JPS60186473A (en) | Silicon nitride sintered body and manufacture | |
| CN110655048A (en) | Preparation method of silicon nitride nanosheet | |
| Dinga et al. | Synthesis of AlON powders through a polymerization template approach by spark plasma sintering |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |