CN102485645A - Method for rapidly combusting and synthesizing silicon nitride powder by using foaming agent capable of producing nitrogen while decomposing as additive - Google Patents
Method for rapidly combusting and synthesizing silicon nitride powder by using foaming agent capable of producing nitrogen while decomposing as additive Download PDFInfo
- Publication number
- CN102485645A CN102485645A CN2010105702360A CN201010570236A CN102485645A CN 102485645 A CN102485645 A CN 102485645A CN 2010105702360 A CN2010105702360 A CN 2010105702360A CN 201010570236 A CN201010570236 A CN 201010570236A CN 102485645 A CN102485645 A CN 102485645A
- Authority
- CN
- China
- Prior art keywords
- silicon nitride
- whipping agent
- nitride powder
- decomposing
- nitrogen
- 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.)
- Granted
Links
Images
Abstract
The invention discloses a method for rapidly combusting and synthesizing silicon nitride powder by using a foaming agent capable of producing nitrogen while decomposing as an additive, which comprises the following steps: in the rapid combustion and synthesis process of silicon nitride, the foaming agent capable of producing nitrogen while decomposing is taken as an auxiliary agent; the foaming agent possesses the purity greater than 99% and comprises an azo compound, a nitroso compound, a sulfohydrazide compound and the like. The method of the invention has the following beneficial effects: 1) the used foaming agent has the advantages of no toxicity, constant color, no odor, no pollution and insolubility in common solvents; 2) the foaming agent of the invention has the advantages of high gas evolution, small particles and good dispersibility; 3) the foaming agent is selected as nitrogen source, so that production security is increased, and the raw material cost is reduced; and 4) the foaming agent discharges a lot of heat while decomposing, so that the combustion and synthesis reaction can be carried out with a faster reaction rate, the instability problem during the combustion process can be solved.
Description
Technical field
The present invention relates to the method for burning synthetic (claiming that also self propagating high temperature is synthetic) beta-silicon nitride powder, the whipping agent that can produce nitrogen during particularly with decomposition is the method for additive rapid combustion synthesizing silicon nitride powder, belongs to the preparing technical field of beta-silicon nitride powder.
Background technology
Silicon nitride ceramics is typical case's representative of advanced structural ceramic material, can be widely used in fields such as machinery, chemical industry, space flight and aviation owing to it has excellent high-temperature mechanics, thermal property and chemicalstability.Alpha-silicon nitride powders is as the starting material of producing silicon nitride ceramics, and its high price has seriously limited the consumption and the scale of silicon nitride ceramics.Therefore, low-cost alpha-silicon nitride powders preparation technology's research and development seem particularly necessary.
The preparation method of the beta-silicon nitride powder of having researched and developed at present has a lot, and wherein representative comprises: silica flour direct nitridation method, carbothermic method, silicon imide decomposition method, plasma method and combustion synthesis method.The Denka etc. of the Stark of some large-scale manufacturers such as Germany, Japan generally adopts direct nitridation method to prepare beta-silicon nitride powder in the world.Its subject matter is to reach 72 hours the production cycle, needs secondary nitrogenize and energy consumption big.Equally, also there are shortcomings such as production cycle length, complex technical process, production cost height in carbothermic method technology; Foreign matter contents such as carbon, oxygen are also higher in the product in addition.Japan UBE company adopts the silicon imide decomposition method to produce commercialized degree beta-silicon nitride powder preferably; The shortcoming that this method exists has: be easy to generate etching problem in complex process, production cost height, the production process, and the cl content in the product is higher.Plasma method is produced beta-silicon nitride powder and is also had shortcomings such as complex equipments, cost is high, energy consumption is big; And on product price and production scale, do not possess the possibility that forms extensive industry yet.Comparatively speaking; By synthetic (the Combustion Synthesis of the burning of the scientist of FSU invention; CS) technology has advantages such as energy-conservation, that product purity is high, synthesis cycle is short, is typical low-cost technology of preparing, with synthesizing silicon nitride powder; Be expected to reduce cost significantly, thereby the silicon nitride ceramics large-scale application is played technological pushing effect.
After the eighties in 20th century, investigation of materials person has carried out a large amount of reports to adopting combustion synthesis technology to prepare beta-silicon nitride powder both at home and abroad.Rate firsts to file such as Russian scientist Merzhanov name be called the patent of " preparation method " (U.S. Patent number US5032370) with high α phase content silicon nitride; But the combustion synthesis reaction gaseous tension that uses in this patent is up to 30 MPa, causes production security relatively poor; In addition, the ammonium salt amount of adding in the reaction raw materials be up to add 60 wt% of silica flour content, make clean productive rate not high; Moreover the Si powder raw material also need pass through special methods such as hydrofluoric acid and carry out pre-treatment, has used the amorphous Si or the silicon imide of different content, has caused the raw materials cost increase.The name of inventions such as Holt J. Birch is called " burning synthetic thin brilliant α phase silicon nitride " (U.S. Patent number US4944930), has adopted 50% the high malicious explosive material NaN that accounts for reactant
3Deng being nitrogenous source, not only can introduce impurity, also be not suitable for safety in production simultaneously.One Chinese patent application number is 01126400.4 to disclose " the synthetic method that prepare the beta-silicon nitride whisker of self propagating high temperature ", and this method adopts oxide compound to make the auxiliary agent of growing.One Chinese patent application number is 200410017913.0 to disclose name and be called " it is brilliant to be equipped with the beta-silicon nitride rod with silicon nitride magnesium as growth auxiliary agent burning synthesis for preparing ", and this method adopts silicon nitride magnesium to make auxiliary agent.Aforementioned two one Chinese patent application are all inevitably introduced oxygen or metallic impurity in product.In a word: prepare beta-silicon nitride powder with traditional combustion synthesis process and have following defective: 1) clean productive rate is low; 2) synthetic cost is high; 3) technological process is unstable; 4) be prone to introduce impurity in the product.This makes and currently still is difficult to adopt combustion synthesis process to come the mass preparation beta-silicon nitride powder.
Summary of the invention
It is the method for additive rapid combustion synthesizing silicon nitride powder that the technical problem that the present invention will solve provides a kind of whipping agent that can produce nitrogen when decomposing; High, the synthetic cost of the clean productive rate of this method is low, stable technical process and can not introduce impurity.
For solving the problems of the technologies described above, the present invention adopts following technical scheme:
A kind of whipping agent that can produce nitrogen when decomposing is the method for additive rapid combustion synthesizing silicon nitride powder; Comprise the steps: that in rapid combustion synthesizing silicon nitride powder process the whipping agent that can produce nitrogen during with decomposition is as the additive in the reaction process.
The whipping agent that further, can produce nitrogen during described decompose comprises one or more the mixture in azo cpd, nitroso compound or the sulfonyl hydrazines compound.
Further; The whipping agent that can produce nitrogen during described decompose be Cellmic C 121 (be called for short: the AC whipping agent) or Diisopropyl azodicarboxylate (be called for short: the AIBN whipping agent) or ABVN the ABVN whipping agent) or N (be called for short:; N'-dinitroso five methyne tetramines (be called for short: the DPT whipping agent) or p-toluene sulfonyl hydrazide (be called for short: the TSH whipping agent) or benzol sulfohydrazide the OBSH whipping agent) etc. the BSH whipping agent) or 4 (be called for short:, the 4'-OBSH (is called for short: the mixture of one or more in.
Further, can produce purity＞99% of the whipping agent of nitrogen during described decompose.
Further, a kind of whipping agent that can produce nitrogen when decomposing is the method for additive rapid combustion synthesizing silicon nitride powder, comprises the steps:
1) preparation of reagent
In silica flour: alpha-silicon nitride powders: the weight part ratio that can produce the whipping agent of nitrogen during decomposition is that 35 ~ 90:0 ~ 50:1 ~ 40 take by weighing raw material and thorough mixing, the preparation reagent;
2) pre-treatment of reagent
The mixed material of step 1) placed on the grinding plant grind, the mixture after the grinding sieves, and is loaded in the container;
3) combustion synthesis reaction
With step 2) in the high pressure reaction assembly put into of container, vacuumize; In high pressure reaction assembly, charge into nitrogen, cause combustion synthesis reaction through local electricignition type of heating again;
4) aftertreatment
After treating that the step 3) reaction finishes, the synthetic product that obtains of furnace cooling burning drops to the pressure in the reactor drum normal atmosphere and unloads sintetics; The clean surface layer is removed the not part of complete reaction; The silicon nitride product of preparation is carried out fragmentation and stage treatment, promptly obtain the beta-silicon nitride powder of homogeneous.
Further, the specific density after mixture sieves said step 2) is 25～70%; On the one hand, make between the powder granule distance be unlikely to far away, combustion reactions is difficult to keep; On the other hand, make between the powder granule distance be unlikely near, nitrogen is difficult to infiltration.
Further, said step 3) mesohigh reaction unit has cooling water jecket, and its role is the cooling reaction device, and silicon powder nitride combustion reactions liberated heat can in time be derived, and the envrionment temperature in the reaction unit is effectively controlled.
Further, the original pressure that charges in the said step 3) behind the nitrogen is 0.5 ~ 5 MPa, and the silicon powder nitride combustion reactions can be kept.
The present invention has following beneficial effect:
1) that the whipping agent that can produce nitrogen when decomposing that adopts among the present invention has is nontoxic, nondiscoloration, no stink, do not pollute, and is insoluble to the advantage of common solvent;
2) it is high to produce the whipping agent gas forming amount of nitrogen when decomposing, and particle is little, good dispersivity, and be main to discharge nitrogen, be difficult for from foam, overflowing;
3) adopt the whipping agent that can produce nitrogen when decomposing to make nitrogenous source, be silicon powder nitride burning synthetic additive, can reduce the required nitrogen pressure of combustion synthesis reaction on the one hand, thereby help increasing production security; On the other hand, can reduce nitrogen use level, thereby help reducing raw materials cost;
The whipping agent that 4) can produce nitrogen when decomposing can be emitted a large amount of heats when decomposing, combustion synthesis reaction is carried out with speed of reaction faster, helps solving the instability problem of combustion processes;
In sum: method provided by the invention helps reducing the production cost of beta-silicon nitride powder, the stability and the production security of increase combustion synthesis process, and can further enhance productivity.
Description of drawings
Fig. 1 is the X ray diffracting spectrum of combustion synthesized product in the embodiment of the invention 1 ~ 5.
Embodiment
Embodiment 1
A kind of whipping agent that can produce nitrogen when decomposing is the method for additive rapid combustion synthesizing silicon nitride powder, comprises the steps:
1) in silica flour: alpha-silicon nitride powders: the weight part ratio of the AC whipping agent of purity＞99% is to take by weighing raw material at 49.5: 49.5: 1;
2) raw material for preparing is placed on the oscillating mill mixed grinding 1 hour, grinds the back powder through sieving,, control making powder blank specific density is 40%, in the container of packing into then;
3) container is put into the combustion synthesis reaction device that has cooling water jecket, lay helical tungsten filamen and titanium valve is done ignition source at an end of powder base; After vacuumizing, in the combustion synthesis reaction device, charge into nitrogen, reach 2 MPa up to pressure; Energising adds the thermal ignition titanium valve to tungsten filament, brings out powder systems generation combustion synthesis reaction;
4) question response finishes the synthetic product that obtains of back furnace cooling burning, and the pressure in the reactor drum is dropped to normal atmosphere and unloads sintetics; The clean surface layer is removed imperfect combustion part; The silicon nitride product of preparation is carried out fragmentation and stage treatment, obtain homogeneous purity 99% beta-silicon nitride powder.
The X ray diffracting spectrum of product is shown among Fig. 11, and the powder of gained is principal phase with the beta phase silicon nitride, and contents of free si is 0.07%.
A kind of whipping agent that can produce nitrogen when decomposing is the method for additive rapid combustion synthesizing silicon nitride powder, comprises the steps:
1) in silica flour: the weight part ratio of the AC whipping agent of purity＞99% is that 90:10 takes by weighing raw material;
2) raw material for preparing was placed on the oscillating mill mixed grinding 1.5 hours, grind the back powder and handle through screening, control making powder blank specific density is 40%, in the container of packing into then;
3) container is put into the combustion synthesis reaction device that has cooling water jecket, lay helical tungsten filamen and titanium valve is done ignition source at an end of powder base; After vacuumizing, in the combustion synthesis reaction device, charge into nitrogen, reach 4.0 MPa up to pressure; Energising adds the thermal ignition titanium valve to tungsten filament, brings out powder systems generation combustion synthesis reaction;
4) question response finishes the synthetic product that obtains of back furnace cooling burning, and the pressure in the reactor drum is dropped to normal atmosphere and unloads sintetics; The clean surface layer is removed imperfect combustion part; The silicon nitride of preparation is carried out fragmentation and stage treatment, obtain homogeneous purity 99% beta-silicon nitride powder.
The X ray diffracting spectrum of product is shown among Fig. 12, and the beta-silicon nitride powder of gained is a principal phase with β mutually, and contents of free si is 0. 15%.
A kind of whipping agent that can produce nitrogen when decomposing is the method for additive rapid combustion synthesizing silicon nitride powder, comprises the steps:
1) in silica flour: alpha-silicon nitride powders: the AC whipping agent of purity＞99%: the weight part ratio of the DPT whipping agent of purity＞99% is that 47:47:3:3 takes by weighing raw material;
2) raw material for preparing was placed on the oscillating mill mixed grinding 1.5 hours, grind the back powder and handle through screening, control making powder blank specific density is 50%, in the container of packing into then;
3) container is put into the combustion synthesis reaction device that has cooling water jecket, lay helical tungsten filamen and titanium valve is done ignition source at an end of powder base; After vacuumizing, in the combustion synthesis reaction device, charge into nitrogen, reach 3 MPa up to pressure; Energising adds the thermal ignition titanium valve to tungsten filament, brings out powder systems generation combustion synthesis reaction;
4) question response finishes the synthetic product that obtains of back furnace cooling burning, and the pressure in the reactor drum is dropped to normal atmosphere and unloads sintetics; The clean surface layer is removed imperfect combustion part; The silicon nitride of preparation is carried out fragmentation and stage treatment, obtain homogeneous purity 99% beta-silicon nitride powder.
The X ray diffracting spectrum of product is shown among Fig. 13, and the beta-silicon nitride powder of gained is a principal phase with α mutually, and contents of free si is 0.05%.
Embodiment 4
A kind of whipping agent that can produce nitrogen when decomposing is the method for additive rapid combustion synthesizing silicon nitride powder, comprises the steps:
1) in silica flour: alpha-silicon nitride powders: the weight part ratio of the DPT whipping agent of purity＞99% is that 40:50:10 takes by weighing raw material;
2) raw material for preparing was placed on the oscillating mill mixed grinding 1.5 hours, grind the back powder and handle through screening, control making powder blank specific density is 35%, in the container of packing into then;
3) container is put into the combustion synthesis reaction device that has cooling water jecket, lay helical tungsten filamen and titanium valve is done ignition source at an end of powder base; After vacuumizing, in the combustion synthesis reaction device, charge into nitrogen, reach 3.5 MPa up to pressure; Energising adds the thermal ignition titanium valve to tungsten filament, brings out powder systems generation combustion synthesis reaction;
4) question response finishes the synthetic product that obtains of back furnace cooling burning, and the pressure in the reactor drum is dropped to normal atmosphere and unloads sintetics; The clean surface layer is removed imperfect combustion part; The silicon nitride of preparation is carried out fragmentation and stage treatment, obtain homogeneous purity 98% beta-silicon nitride powder.
The X ray diffracting spectrum of product is shown among Fig. 14, and the beta-silicon nitride powder of gained is a principal phase with α mutually, has a spot of silit or silicon oxynitride to exist mutually in the powder.
A kind of whipping agent that can produce nitrogen when decomposing is the method for additive rapid combustion synthesizing silicon nitride powder, comprises the steps:
1) in silica flour: the AC whipping agent of purity＞99%: the DPT whipping agent of purity＞99%: the weight part ratio of the p-toluene sulfonyl hydrazide whipping agent of purity＞99% is that 60:20:10:10 takes by weighing raw material;
2) raw material for preparing was placed on the oscillating mill mixed grinding 1.5 hours, grind the back powder and handle through screening, control making powder blank specific density is 40%, in the container of packing into then;
3) container is put into the combustion synthesis reaction device that has cooling water jecket, lay helical tungsten filamen and titanium valve is done ignition source at an end of powder base; After vacuumizing, in the combustion synthesis reaction device, charge into nitrogen, reach 0.5 MPa up to pressure; Energising adds the thermal ignition titanium valve to tungsten filament, brings out powder systems generation combustion synthesis reaction;
4) question response finishes the synthetic product that obtains of back furnace cooling burning, and the pressure in the reactor drum is dropped to normal atmosphere and unloads sintetics; The clean surface layer is removed imperfect combustion part; The silicon nitride of preparation is carried out fragmentation and stage treatment, obtain homogeneous purity 99% beta-silicon nitride powder.
The X ray diffracting spectrum of product is shown among Fig. 15, and the beta-silicon nitride powder of gained is a principal phase with α mutually, has a spot of silit or silicon oxynitride to exist mutually in the powder.
Embodiment 6
Obviously, the above embodiment of the present invention only be for clearly the present invention is described and is done for example, and be not to be qualification to embodiment of the present invention.For the those of ordinary skill in affiliated field, on the basis of above-mentioned explanation, can also make other multi-form variation or change.Here can't give exhaustive to all embodiments.Everyly belong to the row that conspicuous variation that technical scheme of the present invention extends out or change still are in protection scope of the present invention.
Claims (8)
1. the whipping agent that can produce nitrogen when decomposing is the method for additive rapid combustion synthesizing silicon nitride powder; It is characterized in that; Comprise the steps: that in rapid combustion synthesizing silicon nitride powder process the whipping agent that can produce nitrogen during with decomposition is as the additive in the reaction process.
2. the whipping agent that can produce nitrogen when decomposing according to claim 1 is the method for additive rapid combustion synthesizing silicon nitride powder, it is characterized in that: the whipping agent that can produce nitrogen during described the decomposition comprises one or more the mixture in azo cpd, nitroso compound, the sulfonyl hydrazines compound.
3. the whipping agent that can produce nitrogen when decomposing according to claim 1 is the method for additive rapid combustion synthesizing silicon nitride powder; It is characterized in that: the whipping agent that can produce nitrogen during described the decomposition is Cellmic C 121, Diisopropyl azodicarboxylate, ABVN, N; N'-dinitroso five methyne tetramines, p-toluene sulfonyl hydrazide, benzol sulfohydrazide, 4, the mixture of one or more in the 4'-OBSH.
4. be the method for additive rapid combustion synthesizing silicon nitride powder according to claim 2 or the 3 described whipping agents that can produce nitrogen when decomposing, it is characterized in that: purity＞99% that can produce the whipping agent of nitrogen during described the decomposition.
5. the whipping agent that can produce nitrogen when decomposing according to claim 1 is the method for additive rapid combustion synthesizing silicon nitride powder, it is characterized in that, comprises the steps:
1) preparation of reagent
In silica flour: alpha-silicon nitride powders: the weight part ratio that can produce the whipping agent of nitrogen during decomposition is that 35 ~ 90:0 ~ 50:1 ~ 40 take by weighing raw material and thorough mixing, the preparation reagent;
2) pre-treatment of reagent
The mixed material of step 1) placed on the grinding plant grind, the mixture after the grinding sieves, and is loaded in the container;
3) combustion synthesis reaction
With step 2) in the high pressure reaction assembly put into of container, vacuumize; In high pressure reaction assembly, charge into nitrogen, cause combustion synthesis reaction through local electricignition type of heating again;
4) aftertreatment
After treating that the step 3) reaction finishes, the synthetic product that obtains of furnace cooling burning drops to the pressure in the reactor drum normal atmosphere and unloads sintetics; The clean surface layer is removed the not part of complete reaction; The silicon nitride product of preparation is carried out fragmentation and stage treatment, promptly obtain the beta-silicon nitride powder of homogeneous.
6. the whipping agent that can produce nitrogen when decomposing according to claim 5 is the method for additive rapid combustion synthesizing silicon nitride powder, and it is characterized in that: the specific density after mixture sieves said step 2) is 25～70%.
7. the whipping agent that can produce nitrogen when decomposing according to claim 5 is the method for additive rapid combustion synthesizing silicon nitride powder, and it is characterized in that: said step 3) mesohigh reaction unit has cooling water jecket.
8. the whipping agent that can produce nitrogen when decomposing according to claim 5 is the method for additive rapid combustion synthesizing silicon nitride powder, it is characterized in that: the original pressure that charges in the said step 3) behind the nitrogen is 0.5 ~ 5 MPa.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201010570236 CN102485645B (en) | 2010-12-02 | 2010-12-02 | Method for rapidly combusting and synthesizing silicon nitride powder by using foaming agent capable of producing nitrogen while decomposing as additive |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201010570236 CN102485645B (en) | 2010-12-02 | 2010-12-02 | Method for rapidly combusting and synthesizing silicon nitride powder by using foaming agent capable of producing nitrogen while decomposing as additive |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102485645A true CN102485645A (en) | 2012-06-06 |
| CN102485645B CN102485645B (en) | 2013-06-05 |
Family
ID=46151222
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201010570236 Active CN102485645B (en) | 2010-12-02 | 2010-12-02 | Method for rapidly combusting and synthesizing silicon nitride powder by using foaming agent capable of producing nitrogen while decomposing as additive |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102485645B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114716252A (en) * | 2022-04-27 | 2022-07-08 | 中国科学院上海硅酸盐研究所 | Preparation method of easy-to-sinter high-purity silicon nitride powder |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4944930A (en) * | 1986-11-21 | 1990-07-31 | Regents Of The University Of California | Synthesis of fine-grained α-silicon nitride by a combustion process |
| CN1362358A (en) * | 2002-01-22 | 2002-08-07 | 清华大学 | Low pressure combustion process of synthesizing alpha-phase silicon nitride powder |
| CN1433959A (en) * | 2002-01-22 | 2003-08-06 | 北京科技大学 | Process for combustion synthesizing high alpha phase superfine silicon carbide powder and silicon nitride whisker |
| CN101353160A (en) * | 2008-09-09 | 2009-01-28 | 辽宁工业大学 | Synthetic method of silicon nitride nanopowder |
-
2010
- 2010-12-02 CN CN 201010570236 patent/CN102485645B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4944930A (en) * | 1986-11-21 | 1990-07-31 | Regents Of The University Of California | Synthesis of fine-grained α-silicon nitride by a combustion process |
| CN1362358A (en) * | 2002-01-22 | 2002-08-07 | 清华大学 | Low pressure combustion process of synthesizing alpha-phase silicon nitride powder |
| CN1433959A (en) * | 2002-01-22 | 2003-08-06 | 北京科技大学 | Process for combustion synthesizing high alpha phase superfine silicon carbide powder and silicon nitride whisker |
| CN101353160A (en) * | 2008-09-09 | 2009-01-28 | 辽宁工业大学 | Synthetic method of silicon nitride nanopowder |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114716252A (en) * | 2022-04-27 | 2022-07-08 | 中国科学院上海硅酸盐研究所 | Preparation method of easy-to-sinter high-purity silicon nitride powder |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102485645B (en) | 2013-06-05 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101214934A (en) | Self-combustion non-pollution fast preparation method for alpha-phase silicon nitride powder | |
| CN101445223A (en) | Method for preparing low-oxygen high-alpha phase silicon nitride powder by auto-igniting synthesis | |
| CN106744967B (en) | A kind of preparation method of silicon carbide powder | |
| CN100453508C (en) | Chemically excited combustion process for synthesizing Si3N4/SiC composite powder | |
| CN101353160A (en) | Synthetic method of silicon nitride nanopowder | |
| CN108529576B (en) | Silicon nitride and preparation method thereof | |
| CN102583276A (en) | Method for producing regularly shaped alpha-phase silicon nitride powder | |
| CN1286713C (en) | Method for synthesizing silicon nitride powder by atmospheric pressure combustion | |
| CN102199039A (en) | Polymer network preparation method for hexagonal boron nitride ceramic powder with high specific surface area | |
| CN101445224A (en) | Method for preparing low-oxygen aluminum nitride powder by auto-igniting synthesis | |
| CN100443443C (en) | Combustion synthesis method of sub-micron titanium carbide nitride powder | |
| CN1307089C (en) | Temperature-controlling activated self-spreading combustion process of synthesizing alpha-phase SiN powder | |
| CN1264781C (en) | Temperature controlled combustion method for synthesizing powder of silicon nitride in alpha phase | |
| CN104499053A (en) | Method for preparing silicon nitride crystal whisker | |
| CN101774809A (en) | Method for preparing silicon nitride and silicon carbide compounded powder through self-propagating combustion | |
| CN102485645B (en) | Method for rapidly combusting and synthesizing silicon nitride powder by using foaming agent capable of producing nitrogen while decomposing as additive | |
| CN101734632B (en) | Production method of nano silicon nitride powders | |
| CN101531367A (en) | Process for producing silicane | |
| CN112441604B (en) | Method for preparing high-purity fluoride | |
| CN106232523A (en) | Mayenite compound containing imino group anion and preparation method thereof | |
| CN104876196A (en) | Preparation method for producing high purity beta-phase silicon nitride by combustion synthesis method | |
| CN102417168B (en) | Method for producing calcium nitride powder | |
| CN101229916B (en) | Method for combustion synthesis of silicon nitride powder by using polytetrafluoroethylene as additive | |
| CN104528672A (en) | Preparation method of alpha-silicon nitride | |
| RU2327639C2 (en) | Method of producing high purity silicon |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |