CN104671795A - Single-phase alpha-Si3N4 micropowder and preparation method thereof - Google Patents

Single-phase alpha-Si3N4 micropowder and preparation method thereof Download PDF

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CN104671795A
CN104671795A CN201510062292.6A CN201510062292A CN104671795A CN 104671795 A CN104671795 A CN 104671795A CN 201510062292 A CN201510062292 A CN 201510062292A CN 104671795 A CN104671795 A CN 104671795A
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powder
preparation
si3n4
micropowder
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CN104671795B (en
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梁峰
张海军
张少伟
李发亮
鲁礼林
段红娟
刘江昊
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Wuhan University of Science and Engineering WUSE
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Abstract

The invention relates to a single-phase alpha-Si3N4 micropowder and a preparation method thereof. The technical scheme is as follows: the preparation method comprises the following steps: uniformly mixing 5-30 wt% of simple substance silicon powder, 15-45 wt% of solid nitrogen source and 40-80 wt% of halide powder to prepare a mixture; putting the mixture into an electric tube furnace, heating to 1000-1300 DEG C at the heating rate of 2-10 DEG C/minute in a nitrogen atmosphere, and keeping the temperature for 2-6 hours; repeatedly washing the product with deionized water until no white precipitate appears when respectively titrating with AgNO3 and Ca(NO3)2 solutions; and finally, drying at 110 DEG C for 10-24 hours to obtain the single-phase alpha-Si3N4 micropowder. The preparation method has the characteristics of low reaction temperature, low cost, simple synthesis technique, controllable process, high yield and wide industrialization prospects. The particle size of the prepared single-phase alpha-Si3N4 micropowder is 100-500nm; and the single-phase alpha-Si3N4 micropowder has the advantages of no impurity phase, high activity, small particle aggregation and uniform particle size distribution.

Description

A kind of single-phase α-Si 3n 4superfine powder and preparation method thereof
Technical field
The invention belongs to Si 3n 4ultra-fine powder technology field.Be specifically related to a kind of single-phase α-Si 3n 4superfine powder and preparation method thereof.
Background technology
Silicon nitride (Si 3n 4) ceramic composite materials as a kind of functional materials of excellent performance, have a wide range of applications in machinery, electricity/multiple fields such as optics, refractory materials.Si 3n 4common mainly contains two kinds of crystalline structure: α phase all belongs to hexagonal system with β phase, α phase with β phase.The reason forming two kinds of different variants is [Si-N 4] face body structure is piled into two kinds of two-dimensional network crystalline forms in a different manner: α-Si 3n 4stacking sequence be ABCDAB ..., β-Si 3n 4stacking sequence be ABABAB ...α-Si 3n 4for particulate state and β-Si 3n 4for long column shape.α-Si 3n 4be thermodynamically unstable phase, 1300 ~ 1600 DEG C time, α-Si 3n 4tetrahedron rotates 180 ° with c-axis vertical line for axle center, is transformed into high-temperature-phase β-Si 3n 4.Compare and β-Si 3n 4, α-Si 3n 4be conducive to the growth of column crystal in stupalith, be easier to sintering densification and self-enhancement, Si 3n 4the physical strength of stupalith and fracture toughness property can along with α-Si in raw material 3n 4the increase of phase content and improving.Meanwhile, nanometer or submicron order α-Si 3n 4the volume effect that superfine powder has and surface effects can realize the low-temperature sintering of silicon nitride ceramic material, and give the mechanical property of material excellence.Therefore, the particle diameter of beta-silicon nitride powder, α phase content and foreign matter content determine the quality of its quality, and directly affect the quality of ceramic.
Silicon nitride powder weight depends on its preparation method.At present, Si is prepared 3n 4the main method of powder has: silica flour direct nitridation method, carbothermic method and chemical Vapor deposition process etc.
Silica flour direct nitridation method refers to that pure silica flour is at N 2, N 2+ H 2or NH 3reducing atmosphere in react, generate silicon nitride powder, that this method obtains at a lower temperature is α-Si 3n 4with β-Si 3n 4mixture, what obtain under high temperature only has β-Si 3n 4.As " a kind of production method of high content of alpha crystal formation alpha-silicon nitride powders " (CN 102173396 A) patented technology, adopt mechanical activation pre-treatment silicon power raw material 8h, with α-Si 3n 4with nano amorphous Si 3n 4for thinner, pass into nitrogen under normal pressure, Direct-Nitridation at 1350 DEG C, product through vertical lapping machine grinding 7 ~ 10h, prepares submicron, micron order alpha-silicon nitride powders that α phase content is 97.6 again.But the requirement of this preparation method to silica flour particle diameter is higher, and still have part silica flour to remain after reaction, complex process, energy consumption is high.
Carbothermic method refers to SiO 2with the powder N at high temperature of C 2there is nitrogenize and reduction reaction in atmosphere, generate Si 3n 4micro mist.But this method temperature of reaction is high, and α phase content is low, the content of foreign matter content particularly carbon is higher, and powder granule size distribution is uneven; Chemical Vapor deposition process is by the halogenide (SiCl of silicon 4, SiBr 4deng) or the hydrohalogen (SiHCl of silicon 3, SiH 2cl 2deng) at N 2, N 2+ H 2or NH 3reducing atmosphere in directly there is chemical gas phase reaction and generate silicon nitride, the Si that this kind of method is produced 3n 4powder purity is high, granular superfine and evenly, α phase content is high, but reaction process is wayward, expensive raw material price, requires high to production unit.
Therefore, at present for single-phase α-Si 3n 4, all there is certain deficiency in the technology of preparing that superfine powder is carried out.As higher in cost of material, complex technical process, wayward, energy consumption is high or industrialization degree is low; Prepared product purity is lower, powder granule size distribution is uneven or α phase content is low.
Summary of the invention
The present invention is intended to the deficiency overcoming prior art existence, provides the single-phase α-Si that a kind of temperature of reaction is low, cost is low, synthesis technique is simple, process is easy to control, productive rate is high and industrialization prospect is large 3n 4the preparation method of superfine powder; With single-phase α-Si prepared by the method 3n 4superfine powder activity is high, particle agglomeration is little, diameter of particle is evenly distributed and purity is high.
For achieving the above object, the technical solution used in the present invention is: first mixed by the halogenide powder of the simple substance silica flour of 5 ~ 30wt%, the solid-state nitrogenous source of 15 ~ 45wt% and 40 ~ 80wt%, obtained mixture; Again described mixture is inserted in electric tube furnace, rise to 1000 ~ 1300 DEG C with the temperature rise rate of 2 ~ 10 DEG C/min in a nitrogen atmosphere, be incubated 2 ~ 6 hours; Then products therefrom deionized water is cleaned repeatedly, until use AgNO respectively 3with Ca (NO 3) 2till no longer there is white precipitate in solution titration; Last under 110 DEG C of conditions dry 10 ~ 24 hours, obtain single-phase α-Si 3n 4superfine powder.
Si content >=95wt% in described simple substance silica flour, particle diameter≤50 μm.
Described solid-state nitrogenous source is technical pure or for analytical pure, particle diameter all≤200 μm; Described solid-state nitrogenous source is more than one in ammonium chloride, urea and trimeric cyanamide.
Described halogenide powder is technical pure or for analytical pure, particle diameter all≤200 μm; Described halogenide powder is more than one in sodium-chlor, Potassium monofluoride and Sodium Fluoride.
Owing to adopting technique scheme, the present invention compared with prior art has following positively effect and outstanding feature:
1, the mixing of the present invention's realization response thing atomic scale in melting salt, reacted constituent mobility is in the liquid phase strengthened, and rate of diffusion significantly improves; Effectively can control reaction process, reduce temperature of reaction and Reaction time shorten;
2, the present invention more easily can control the shape and size of crystal grain by molten-salt growth method, and powder granularity is 100 ~ 500nm, and each component proportion of synthetic product is accurate, uniform composition, segregation-free;
3, the present invention is in reaction process and cleaning process subsequently, is conducive to the removing of impurity, forms high-purity reactant, without dephasign;
4, raw material sources of the present invention are extensive and cheap, and production cost is low, have very large industrialization prospect;
5, the even particulate dispersion of product prepared of the present invention is in melting salt, avoids and is interconnected, make particle dispersion fine, significantly reduces the generation of dissolving agglomeration after washing.
Therefore, the present invention has the advantages that temperature of reaction is low, cost is low, synthesis technique is simple, process is easy to control, productive rate is high and industrialization prospect is large; Prepared single-phase α-Si 3n 4superfine powder granularity is 100 ~ 500nm, and without dephasign, activity is high, particle agglomeration is little and even particle size distribution.
Accompanying drawing explanation
Fig. 1 is the single-phase α of one-Si prepared by the present invention 3n 4the XRD figure spectrum of powder;
Fig. 2 is the single-phase α-Si shown in Fig. 1 3n 4the SEM figure of powder;
Fig. 3 is the EDS figure of arrow pointed location in Fig. 2.
Embodiment
Below in conjunction with the drawings and specific embodiments, the present invention will be further described, the restriction not to its protection domain.
For avoiding repetition, first by as follows for the raw material Unify legislation involved by this embodiment, repeat no more in embodiment:
Si content >=95wt% in described simple substance silica flour, particle diameter≤50 μm.
Described ammonium chloride, urea and trimeric cyanamide are technical pure or are analytical pure, particle diameter all≤200 μm.
Described sodium-chlor, Potassium monofluoride and Sodium Fluoride are technical pure or are analytical pure, particle diameter all≤200 μm.
Embodiment 1
A kind of single-phase α-Si 3n 4superfine powder and preparation method thereof.First the halogenide powder of the simple substance silica flour of 10 ~ 20wt%, the solid-state nitrogenous source of 15 ~ 30wt% and 60 ~ 75wt% is mixed, obtained mixture; Again described mixture is inserted in electric tube furnace, rise to 1200 ~ 1300 DEG C with the temperature rise rate of 2 ~ 5 DEG C/min in a nitrogen atmosphere, be incubated 2 ~ 4 hours; Then products therefrom deionized water is cleaned repeatedly, until use AgNO respectively 3with Ca (NO 3) 2till no longer there is white precipitate in solution titration; Last under 110 DEG C of conditions dry 10 ~ 24 hours, obtain single-phase α-Si 3n 4superfine powder.
In the present embodiment: described solid-state nitrogenous source is trimeric cyanamide; Described halogenide powder is the mixture of the sodium-chlor of 70 ~ 90wt% and the Sodium Fluoride of 10 ~ 30wt%.
Fig. 1 is the single-phase α of one-Si prepared by embodiment 3n 4the XRD figure spectrum of powder; Fig. 2 is the single-phase α-Si shown in Fig. 1 3n 4the SEM figure of powder; Fig. 3 is the EDS figure of arrow pointed location in Fig. 2.As can be seen from Fig. 1 ~ Fig. 3: the single-phase α-Si prepared by the present embodiment 3n 4superfine powder purity is high, particle soilless sticking, and granularity is 100 ~ 200nm.
Embodiment 2
A kind of single-phase α-Si 3n 4superfine powder and preparation method thereof.First the halogenide powder of the simple substance silica flour of 10 ~ 20wt%, the solid-state nitrogenous source of 15 ~ 30wt% and 60 ~ 75wt% is mixed, obtained mixture; Again described mixture is inserted in electric tube furnace, rise to 1100 ~ 1200 DEG C with the temperature rise rate of 2 ~ 5 DEG C/min in a nitrogen atmosphere, be incubated 2 ~ 4 hours; Then products therefrom deionized water is cleaned repeatedly, until use AgNO respectively 3with Ca (NO 3) 2till no longer there is white precipitate in solution titration; Last under 110 DEG C of conditions dry 10 ~ 24 hours, obtain single-phase α-Si 3n 4superfine powder.
In the present embodiment: described solid-state nitrogenous source is the mixture of the trimeric cyanamide of 50 ~ 70wt% and the ammonium chloride of 30 ~ 50wt%; Described halogenide powder is Sodium Fluoride.
Single-phase α-Si prepared by the present embodiment 3n 4superfine powder body purity is high, particle soilless sticking, and granularity is 150 ~ 250nm.
Embodiment 3
A kind of single-phase α-Si 3n 4superfine powder and preparation method thereof.First the halogenide powder of the simple substance silica flour of 5 ~ 15wt%, the solid-state nitrogenous source of 10 ~ 25wt% and 70 ~ 80wt% is mixed, obtained mixture; Again described mixture is inserted in electric tube furnace, rise to 1000 ~ 1100 DEG C with the temperature rise rate of 5 ~ 10 DEG C/min in a nitrogen atmosphere, be incubated 4 ~ 6 hours; Then products therefrom deionized water is cleaned repeatedly, until use AgNO respectively 3with Ca (NO 3) 2till no longer there is white precipitate in solution titration; Last under 110 DEG C of conditions dry 10 ~ 24 hours, obtain single-phase α-Si 3n 4superfine powder.
In the present embodiment: described solid-state nitrogenous source is urea; Described halogenide powder is Potassium monofluoride.
Single-phase α-Si prepared by the present embodiment 3n 4superfine powder purity is high, particle soilless sticking, and granularity is 300 ~ 400nm.
Embodiment 4
A kind of single-phase α-Si 3n 4superfine powder and preparation method thereof.First the halogenide powder of the simple substance silica flour of 5 ~ 15wt%, the solid-state nitrogenous source of 10 ~ 25wt% and 70 ~ 80wt% is mixed, obtained mixture; Again described mixture is inserted in electric tube furnace, rise to 1100 ~ 1200 DEG C with the temperature rise rate of 5 ~ 10 DEG C/min in a nitrogen atmosphere, be incubated 4 ~ 6 hours; Then products therefrom deionized water is cleaned repeatedly, until use AgNO respectively 3with Ca (NO 3) 2till no longer there is white precipitate in solution titration; Last under 110 DEG C of conditions dry 10 ~ 24 hours, obtain single-phase α-Si 3n 4superfine powder.
In the present embodiment: described solid-state nitrogenous source is the mixture of the urea of 50 ~ 70wt% and the trimeric cyanamide of 30 ~ 50wt%; Described halogenide powder is the mixture of the sodium-chlor of 50 ~ 60wt% and the Potassium monofluoride of 40 ~ 50wt%.
Single-phase α-Si prepared by the present embodiment 3n 4superfine powder purity is high, particle soilless sticking, and granularity is 350 ~ 500nm.
Embodiment 5
A kind of single-phase α-Si 3n 4superfine powder and preparation method thereof.First the halogenide powder of the simple substance silica flour of 15 ~ 30wt%, the solid-state nitrogenous source of 25 ~ 45wt% and 40 ~ 60wt% is mixed, obtained mixture; Again described mixture is inserted in electric tube furnace, rise to 1000 ~ 1100 DEG C with the temperature rise rate of 5 ~ 10 DEG C/min in a nitrogen atmosphere, be incubated 4 ~ 6 hours; Then products therefrom deionized water is cleaned repeatedly, until use AgNO respectively 3with Ca (NO 3) 2till no longer there is white precipitate in solution titration; Last under 110 DEG C of conditions dry 10 ~ 24 hours, obtain single-phase α-Si 3n 4superfine powder.
In the present embodiment: described solid-state nitrogenous source is ammonium chloride; Described halogenide powder is sodium-chlor.
Single-phase α-Si prepared by the present embodiment 3n 4superfine powder purity is high, particle soilless sticking, and granularity is 150 ~ 200nm.
Embodiment 6
A kind of single-phase α-Si 3n 4superfine powder and preparation method thereof.First the halogenide powder of the simple substance silica flour of 15 ~ 30wt%, the solid-state nitrogenous source of 25 ~ 45wt% and 40 ~ 60wt% is mixed, obtained mixture; Again described mixture is inserted in electric tube furnace, rise to 1200 ~ 1300 DEG C with the temperature rise rate of 2 ~ 5 DEG C/min in a nitrogen atmosphere, be incubated 4 ~ 6 hours; Then products therefrom deionized water is cleaned repeatedly, until use AgNO respectively 3with Ca (NO 3) 2till no longer there is white precipitate in solution titration; Last under 110 DEG C of conditions dry 10 ~ 24 hours, obtain single-phase α-Si 3n 4superfine powder.
In the present embodiment: described solid-state nitrogenous source is the mixture of the urea of the trimeric cyanamide of 50 ~ 60wt%, the ammonium chloride of 20 ~ 30wt% and 20 ~ 30wt%; Described halogenide powder be the sodium-chlor of 45 ~ 60wt%, the Sodium Fluoride of 25 ~ 35wt% and 15 ~ 20 the mixture of wt% Potassium monofluoride.
Single-phase α-Si prepared by the present embodiment 3n 4superfine powder purity is high, particle soilless sticking, and granularity is 200 ~ 300nm.
Embodiment 7
A kind of single-phase α-Si 3n 4superfine powder and preparation method thereof.First the halogenide powder of the simple substance silica flour of 15 ~ 30wt%, the solid-state nitrogenous source of 25 ~ 45wt% and 40 ~ 60wt% is mixed, obtained mixture; Again described mixture is inserted in electric tube furnace, rise to 1100 ~ 1200 DEG C with the temperature rise rate of 2 ~ 5 DEG C/min in a nitrogen atmosphere, be incubated 2 ~ 4 hours; Then products therefrom deionized water is cleaned repeatedly, until use AgNO respectively 3with Ca (NO 3) 2till no longer there is white precipitate in solution titration; Last under 110 DEG C of conditions dry 10 ~ 24 hours, obtain single-phase α-Si 3n 4superfine powder.
In the present embodiment: described solid-state nitrogenous source is the mixture of the ammonium chloride of 50 ~ 70wt% and the urea of 30 ~ 50wt%; Described halogenide powder is the mixture of the Sodium Fluoride of 50 ~ 60wt% and the Potassium monofluoride of 40 ~ 50wt%.
Single-phase α-Si prepared by the present embodiment 3n 4superfine powder purity is high, particle soilless sticking, and granularity is 250 ~ 350nm.
This embodiment compared with prior art has following positively effect and outstanding feature:
1, the mixing of this embodiment realization response thing atomic scale in melting salt, reacted constituent mobility is in the liquid phase strengthened, and rate of diffusion significantly improves; Effectively can control reaction process and reduce temperature of reaction;
2, this embodiment more easily can control the shape and size of crystal grain by molten-salt growth method, and powder granularity is 100 ~ 500nm.The each component proportion of synthetic product is accurate, uniform composition, segregation-free;
3, this embodiment is in reaction process and cleaning process subsequently, is conducive to the removing of impurity, forms high-purity reactant, without dephasign;
4, the even particulate dispersion of product prepared of this embodiment is in melting salt, avoids and is interconnected, make particle dispersion fine, significantly reduces the generation of dissolving agglomeration after washing;
5, the raw material sources of this embodiment are extensive and cheap, and production cost is low, have very large industrialization prospect of production.
Therefore, this embodiment has the advantages that temperature of reaction is low, cost is low, synthesis technique is simple, process is easy to control, productive rate is high; Prepared single-phase α-Si 3n 4superfine powder granularity is 100 ~ 500nm, and without dephasign, activity is high, particle agglomeration is little and even particle size distribution.

Claims (1)

1. a single-phase α-Si 3n 4the preparation method of superfine powder, is characterized in that first being mixed by the halogenide powder of the simple substance silica flour of 5 ~ 30wt%, the solid-state nitrogenous source of 15 ~ 45wt% and 40 ~ 80wt%, obtained mixture; Again described mixture is inserted in electric tube furnace, rise to 1000 ~ 1300 DEG C with the temperature rise rate of 2 ~ 10 DEG C/min in a nitrogen atmosphere, be incubated 2 ~ 6 hours; Then products therefrom deionized water is cleaned repeatedly, until use AgNO respectively 3with Ca (NO 3) 2till no longer there is white precipitate in solution titration; Last under 110 DEG C of conditions dry 10 ~ 24 hours, obtain single-phase α-Si 3n 4superfine powder.
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Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105483823A (en) * 2015-12-04 2016-04-13 烟台同立高科新材料股份有限公司 Silicon nitride powder for solar polysilicon ingot casting and preparation method thereof
CN108059133A (en) * 2017-12-11 2018-05-22 宁波爱克创威新材料科技有限公司 Nano-silicon nitride and preparation method thereof
CN108610056A (en) * 2018-07-24 2018-10-02 广东工业大学 A kind of silicon nitride ceramics and preparation method thereof
CN111484334A (en) * 2020-04-24 2020-08-04 武汉科技大学 High α phase silicon nitride powder and preparation method thereof
CN112794332A (en) * 2021-01-12 2021-05-14 北京科技大学 Method for removing boron impurities in metallurgical silicon by nitridation-purification

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CN1562735A (en) * 2004-03-19 2005-01-12 山东大学 Method for preparing powder material of silicon nitride under low temperature
CN101259957A (en) * 2008-03-28 2008-09-10 山东大学 Method for preparing silicon nitride powder material under low temperature

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CN1038250A (en) * 1988-05-24 1989-12-27 苏联科学院结构宏观动力学研究所 Preparation method with ammonification silicon of high content of alpha-phase
CN1562735A (en) * 2004-03-19 2005-01-12 山东大学 Method for preparing powder material of silicon nitride under low temperature
CN101259957A (en) * 2008-03-28 2008-09-10 山东大学 Method for preparing silicon nitride powder material under low temperature

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105483823A (en) * 2015-12-04 2016-04-13 烟台同立高科新材料股份有限公司 Silicon nitride powder for solar polysilicon ingot casting and preparation method thereof
CN108059133A (en) * 2017-12-11 2018-05-22 宁波爱克创威新材料科技有限公司 Nano-silicon nitride and preparation method thereof
CN108610056A (en) * 2018-07-24 2018-10-02 广东工业大学 A kind of silicon nitride ceramics and preparation method thereof
CN108610056B (en) * 2018-07-24 2021-07-06 广东工业大学 Silicon nitride ceramic and preparation method thereof
CN111484334A (en) * 2020-04-24 2020-08-04 武汉科技大学 High α phase silicon nitride powder and preparation method thereof
CN111484334B (en) * 2020-04-24 2022-06-07 武汉科技大学 High alpha-phase silicon nitride powder and preparation method thereof
CN112794332A (en) * 2021-01-12 2021-05-14 北京科技大学 Method for removing boron impurities in metallurgical silicon by nitridation-purification

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