CN102173396B - Production method of high-content alpha-crystal form silicon nitride powders - Google Patents
Production method of high-content alpha-crystal form silicon nitride powders Download PDFInfo
- Publication number
- CN102173396B CN102173396B CN201110025965A CN201110025965A CN102173396B CN 102173396 B CN102173396 B CN 102173396B CN 201110025965 A CN201110025965 A CN 201110025965A CN 201110025965 A CN201110025965 A CN 201110025965A CN 102173396 B CN102173396 B CN 102173396B
- Authority
- CN
- China
- Prior art keywords
- silicon nitride
- silica flour
- alpha
- weight
- powder
- 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.)
- Expired - Fee Related
Links
Images
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/10—Process efficiency
Abstract
The invention discloses a production method of silicon nitride powders, in particular relates to a novel production method of silicon nitride powders with high content of alpha-Si3N4, and belongs to the technical field of inorganic chemistry. The method comprises the following steps: firstly pre-treating powdery raw materials by mechanical activation, and feeding a mixed diluting agent of alpha-Si3N4 and non-crystalline Si3N4 during the direct nitridation of silicon powders at a high temperature under normal pressure. By controlling the addition ratio of the diluting agent and the nitridation time and temperature, the silicon nitride powders with high content of alpha-Si3N4 are synthesized. The process improves the activity of solid-phase reactants, promotes the reaction between Si and N2, does not need high-temperature and high-pressure conditions, is easy to operate, adopts easily-available raw materials, increases the purity of products, has a low coat and a high efficiency, and is environment-friendly and energy-saving. The process is economical and highly-efficient and suitable for large-scale production.
Description
Technical field
The present invention relates to a kind of working method of alpha-silicon nitride powders, relate in particular to a kind of α-Si
3N
4The new process for producing that content is higher belongs to technical field of inorganic.
Background technology
Silicon nitride (Si
3N
4) be a kind of important structured material, have the title of " all-round champion " in the stupalith.It is a kind of superhard material, is the excellent high-temperature structured material, is again new-type functional material.Itself has oilness, and wear-resistant, except that hydrofluoric acid, it not with other inorganic acid reaction; Resistance to corrosion is strong, and is anti-oxidant during high temperature, and it can also resist thermal shock; In air, be heated to more than 1000 ℃, sharply cooling sharply heating can be not cracked more yet.Specific to the physicals aspect, silicon nitride material have the hardness height, wear-resistant, Young's modulus is big, intensity is high, high temperature resistant, characteristics such as thermal expansivity is little, thermal conductivity is big, good thermal shock, density is low, skin friction coefficient is little, electrical insulation capability is good.Silicon nitride ceramics is suitable for the structured material as various special purposes; Application Areas relates to industries such as machinery, chemical industry, electronics, military project; Had very wide application prospect in fields such as automobile, machinery, metallurgy and chemical engineerings, and be penetrated into space technology gradually, a plurality of stratospheres such as ocean exploitation, electronic technology, health care, nondestructive testing, control automatically, broadcast television.21 century, silicon nitride ceramics continued as same metal, organic polymer material the bigger effect of progress, development of science and technology performance of human society.
Nano-silicon nitride has two kinds of crystal formations: metastable low temperature is six side α-Si mutually
3N
4With stable high temperature six side β-Si mutually
3N
4, α-Si
3N
4Hardness is greater than β-Si
3N
4, and β-Si
3N
4Toughness is greater than α-Si
3N
4The particle diameter of beta-silicon nitride powder, α, β phase content and foreign matter content have determined the quality of its quality; And directly influence the quality of ceramic; If to such an extent as to the particle of beta-silicon nitride powder very carefully reaches nano level or submicron order; Or the reinforcement item that wherein adds is nano level or submicron order, and the toughness of pottery will increase considerably so, thereby adapts to the needs of various occasions.Preparation high-performance ceramic goods are very high to the requirement of beta-silicon nitride powder.And the beta-silicon nitride powder quality depends on its preparation method; Preparing method commonly used at present has: silica flour direct nitridation method, carbothermic method, silicon halide ammonolysis process, preparation precursor process, chemical double decomposition, in-situ synthesis, silicon alloy ammonolysis process etc.; Ubiquity is not enough as follows: by macrobead silicon nitride, the preparation of heterogeneous powder sintering; Fragility is big, lack of homogeneity, safety are low, toughness and intensity difference, makes its application receive bigger restriction.And the silica flour direct nitridation method prepares enough height of beta-silicon nitride powder requirement nitrogen pressure, to realize Si and N
2Abundant contact.The synthetic Si of general burning
3N
4The nitrogen pressure lower bound be 3MPa, but sometimes up to more than the 100MPa.Adopt the high pressure synthesis technique not only high but also increased production cost, also brought potential safety hazard simultaneously to production because of facility investment.Really it seems the Si of domestic the most representative enterprise production from the index test of domestic and international beta-silicon nitride powder and examination sintering
3N
4Average grain is about 3 microns, and metals content impurity is higher, be difficult to reach the specification product requirement, and the powder of import is below 0.7 micron.Therefore, for meeting the need of market, suitability for industrialized production ultra micro, high-quality alpha-silicon nitride powders are the problem that needs to be resolved hurrily in the domestic silicon nitride industry development, and be very urgent.Key is its synthesis technique is improved.
Summary of the invention
To the prior art situation, the object of the invention is existing technology is improved, and provides that a kind of alpha crystalline form content is high, impurity is few, the working method of ultramicrofine alpha-silicon nitride powders, satisfies the silicon nitride practical application request.
The present invention adopts the silica flour direct nitridation method, and promptly purified silica flour generates silicon nitride through nitrogen to the silica flour internal divergence under the high temperature in nitrogen atmosphere.But in nitrogenizing reaction, also be accompanied by the sintering process of silica flour; Hindered the further nitrogenize of silica flour, the present invention improves its synthesis technique, in the silica flour biscuit, introduces silicon nitride and makees thinner; Improve the nitrogenize efficient of silica flour; Silicon amount residual in the product is reduced, and to the nitriding temperature that influence the silicon nitride transformation efficiency, nitriding velocity, and technological factor such as silicon particle size inquire into, with realization the object of the invention.
Technical scheme is following:
(1) at first through mechanical activation mode pre-treatment silica flour, makes raw material silica flour refinement and decrystallized, thereby improve solid state reaction agent activity, strengthen Si-N
2Between the reaction of gas-solid phase interface, improve Si-N under low nitrogen temperature and the low pressure
2The heat release combustion velocity.During grinding, the silicon nitride ball milling of 3 times of polymethyl acrylic acid and silica flour weight that adds water, the silica flour weight 0.2% of silica flour weight 90% is situated between, and prepares abrasive material.
(2) add α-Si
3N
4With nano amorphous Si
3N
4Mixing prevents silica flour from sintering as thinner, and the while is as the nucleus of resultant; Silica flour and mixing diluents is even.Composite thinning agent α-Si
3N
4With nano amorphous Si
3N
4Weight ratio is 1: 1; The composite thinning agent addition is 20% of a silica flour weight.
(3) dry silica flour and thinner under the nitrogen protection atmosphere under the normal pressure, feed nitrogen with certain flow, displace furnace air; Be heated to 1350 ℃ then, slowly rotate burner, prevent that on the one hand the silica flour bonding wall and the nitrogenize product that melt from luming, can material be disperseed on the other hand, the reinforcement silica flour contacts with nitrogen, and silica flour and nitrogen are fully reacted.
(4) be cooled to room temperature after, put into and be embedded with teflon-lined ball grinder or nylon jar and grind synthetic Si
3N
4Powder: add Si
3N
4The water of weight 90%, Si
3N
4The polymethyl acrylic acid of weight 0.2% and Si
3N
4The silicon nitride ball milling that weight is 3 times is situated between, and grinds synthetic Si
3N
4Powder.After grinding 5-15h, the size range of powder is at 0.696 μ m-0.515 μ m.Sieve filtering mill of slurry is situated between, grinds lumps after the oven dry after sieve.
In actual production, can adopt gradient temperature programming type of heating through microcomputerized control, segmentation is incubated, heats up at a slow speed, improves the effect of silicon powder nitride.
Principle and advantage are: the present invention at first adopts mechanical activation silicon grain, reduces powder particles, and crystal grain thinning increases crystal grain inner microstrain and defective, increases Si-N
2Reaction interface plays and strengthens Si-N
2The effect of reaction, thus it is active to improve reagent, and temperature of reaction is reduced significantly.This technological process does not need high temperature and high pressure environment, and is simple to operate, and raw material is easy to get, and the high and low cost of product purity, efficient, Environmental Safety, energy-conservation are an economy, the efficient and technology circuit that can carry out scale operation.
High-content micron α-Si that the present invention makes
3N
4Technical indicator meets or exceeds Q/GYHT001-2010, and its minimum particle diameter, very big specific surface area and higher chemical property can significantly improve the sintering densification degree of silicon nitride, reduce sintering temperature, save energy.Because the particle size of ceramic powder has determined the microtexture and the macro property of stupalith; If the particle packing of silicon nitride powder is even; Fire and shrink unanimity and uniform crystal particles is grown up, the microdefect that particle hour is produced more is more little, and the intensity of prepared material is just corresponding high more; So just fragility be can overcome effectively, snappiness and processability improved.Its performance of the silicon nitride of different α, β phase content is different, high-content micron α-Si that the present invention is made
3N
4Be applied in the stupalith; Microstructure shows, crystal grain, crystal boundary and the combination size between them all are in nanometer level (1nm～100nm), and the intensity of stupalith is increased substantially; Many deficiencies of engineering ceramics have been overcome, for frontier has been opened up in the application that substitutes engineering ceramics.
Description of drawings
Fig. 1 process route chart of the present invention;
The composite thinning agent adding proportion is to the influence of nitridation process during the following nitrogenize 10min of 350 ℃ of Figure 21;
The silicon nitride XRD spectrum of Fig. 3 after the different mechanical activation time handles;
Fig. 4 composite thinning agent add 20% and nitridation time when being 10min nitriding temperature to the influence of nitridation process;
350 ℃ of following composite thinning agents of Figure 51 add the influence to nitridation process of 20% o'clock nitridation time;
Make the XRD spectrum of silicon nitride under Fig. 6 experiment condition of the present invention;
Make the silicon nitride particle size distribution figure under Fig. 7 experiment condition of the present invention.
Crystal formation is analyzed with Bruker D8 FOCUS type X-ray diffraction
Embodiment
For the present invention is better explained, it is following to lift embodiment in conjunction with process of the test:
1, main raw material(s): silica flour, technical grade, purity>=99.7%; α-Si
3N
4, micron amorphous Si
3N
4With nano amorphous Si
3N
4High pure nitrogen, purity 99.99% is commercially available article.
2, experimental technique
At first grind concrete grammar: the silicon nitride ball milling of 3 times of polymethyl acrylic acid and silica flour weight that adds water, the silica flour weight 0.2% of silica flour weight 90% is situated between, and prepares abrasive material.Put into and be embedded with teflon-lined ball grinder or nylon jar, in agitated ball mill and two big or small planetary ball mills, grind respectively.Milling time is respectively 5,10,15,20,25 ..., 50,100h, the granularity Detection analysis is carried out in sampling respectively.After grinding reaches needed granularity, stop to grind.Sieve filtering mill of slurry is situated between, grinds lumps after the oven dry after sieve.
Then with the silica flour after the activation and α-Si
3N
4Or micron amorphous Si
3N
4Or nano amorphous Si
3N
4Thinner is packed in the roasting kiln furnace chamber.Before beginning heating, the nitrogen flow feeding roasting kiln furnace chamber with 2.0L/min continues 30min, air in the displacement furnace chamber.Feed with the 1.0L/min nitrogen flow then, slowly rotate roasting kiln, can prevent that on the one hand the silica flour bonding wall and the nitrogenize product that melt from luming, can material be disperseed on the other hand, the reinforcement silica flour contacts with nitrogen.After experiment is accomplished, treat that sample hose is cooled to room temperature after, pour out and collect product, add Si
3N
4The water of weight 90%, Si
3N
4The polymethyl acrylic acid of weight 0.2% and Si
3N
4The silicon nitride ball milling that weight is 3 times is situated between, and grinds synthetic Si
3N
4Powder is analyzed sample.
3, result and discussion
3.1 the thinner kind is to the influence of nitridation process
Silica flour is the synthetic Si of direct nitrogenize under very high temperature
3N
4The time, fusing appears in silica flour, forms pelletizing easily, and is obvious from sintering phenomenon, causes the pore between the powder to block sealing, hindered the further nitrogenize of silica flour.Therefore, in silica flour, add an amount of Si
3N
4As thinner, be the effective way of avoiding occurring above-mentioned phenomenon.When the adding proportion of three kinds of thinners is respectively 50%, nitriding temperature is 1350 ℃, and nitridation time is 10min, and the silicon nitride of production is as shown in table 1.
Silicon nitride was formed when table 1 added the different sorts thinner
Can find out, under the same conditions, add α-Si
3N
4As thinner, the transformation efficiency of silicon is the highest, reaches 99.4%, and adds micron amorphous Si
3N
4As thinner, the transformation efficiency of silicon is lower, has only 77.6%, therefore, uses α-Si
3N
4As thinner, more help promoting silicon to Si
3N
4Conversion, but the β phase content is higher in the nitrogenize product, because α-Si
3N
4At high temperature will change mutually to β.With micron amorphous Si
3N
4Compare, select nano amorphous Si for use
3N
4During as thinner, the transformation efficiency of silicon is higher, β-Si in the nitrogenize product
3N
4Content is lower.With regard to the transformation efficiency that promotes silicon, α-Si
3N
4Best results, secondly be nano amorphous Si
3N
4, micron amorphous Si
3N
4Effect relatively poor, and with nano amorphous Si
3N
4During for thinner, β-Si in the nitrogenize product
3N
4Content is lower.Therefore,, make in the nitrogenize product β phase content keep lower simultaneously, select α-Si for use in order to obtain the transformation efficiency of higher silicon
3N
4With nano amorphous Si
3N
4Mixing is preferable selection as thinner.
Under these conditions, with α-Si
3N
4With nano amorphous Si
3N
4Mixing is as thinner, and silicon nitride is formed like table 2:
Table 2
So select α-Si for use in the subsequent experimental
3N
4With nano amorphous Si
3N
4Composite thinning agent, both part by weight are 1: 1.
3.2 the thinner adding proportion is to the influence of nitridation process
When nitriding temperature be 1450 ℃, when nitridation time is 10min, the composite thinning agent adding proportion to the influence of nitridation process shown in accompanying drawing 2.
In silica flour, do not add Si
3N
4The time, residual a large amount of free silica in the product, and the thicker metal pelletizing of a large amount of diameters appears, this is that because at high temperature pelletizing is formed in the silica flour fusing, nitrogenizing reaction only carries out on the pelletizing surface.When in silica flour, adding an amount of composite thinning agent, after the silicon of silicon powder surface is fused into liquid phase,, stoped liquid-state silicon to form pelletizing because thinner is dispersed in around the silica flour, promoted the carrying out of nitrogenizing reaction, the nitrogenize product is the shot shape.Can know that by accompanying drawing 2 along with the increase of thinner adding proportion in the experiment material, the transformation efficiency of silicon obviously increases, but when the thinner adding proportion surpassed 10%, the transformation efficiency of silicon changed not obvious.Simultaneously, along with the increase of thinner adding proportion, β-Si in the nitrogenize product
3N
4Content but reducing, its reason is that the thinner adding proportion is many more, the silicon liquid of fusing is dispersed in the thinner surface more easily, evaporation more easily cause liquid phase to reduce, thereby β reduces mutually.Therefore, after taking all factors into consideration, adding proportion is 20% o'clock, and nitriding result is best.
3.3 the influence of silica flour mechanical activation
With granularity is 44 μ m, and purity is composite thinning agent α-Si of 5 μ m greater than the silica flour and the mean particle size of 98% (massfraction)
3N
4Powder mixes, and the powder that mixes is put into the high energy vibration ball mill mix and activation treatment, and both mass ratioes are 10: 2, and vibrational frequency is 23.2Hz.With X-ray diffraction (x-ray diffraction, XRD) appearance (Cu K
a) respectively to grinding 8h, the composition of the pre-treatment powder of 12h is analyzed.
Can be found out by accompanying drawing 3: along with the prolongation of milling time, the diffraction peak intensity of Si obviously descends, and it is generally acknowledged that mechanical mill can cause the abundant refinement of silica flour; Simultaneously, the long-range order degree of the inner atomic arrangement of powder particle descends, and the non-crystallization degree of powder obviously improves.Under the effect of mechanical force, initial period mainly is the minimizing of powder granule size and the increase of surface-area in the process of lapping, but after acquiring a certain degree; Owing to balance appears in short grained gathering; The size that is powder no longer changes with the prolongation of milling time, but this balance and do not mean that the constant of powder property, if continue to apply mechanical force; Energy just can store in a variety of forms, causes that powder section is decrystallized.This mechanical activation causes that amorphous and nanocrystalline coexistence improve reactive behavior in the reagent, helps silica flour under lower nitrogen temperature and pressure, directly to generate Si with the synthetic mode of burning
3N
4Powder.In sum, adopt mechanical activation 8h.
3.4 nitriding temperature is to the influence of nitridation process
When the thinner adding proportion be 20%, when nitridation time is 10min, nitriding temperature to the influence of nitridation process shown in accompanying drawing 4.In 1050 ℃～1550 ℃ TRs, along with nitriding temperature increases, the transformation efficiency of silicon constantly increases, and free silicone content constantly reduces in the nitrogenize product, also showed increased of β phase content in the nitrogenize product.When nitriding temperature be 1350 ℃, when nitridation time is 10min, the transformation efficiency of silicon reaches 98.6%, silica flour is nitrogenize fully basically, α-Si
3N
4Content reaches more than 95%.When nitriding temperature is higher than 1350 ℃, continue the rising nitriding temperature, the transformation efficiency of silicon is constant basically, but the β phase content continues to increase.Therefore, for obtaining high content of alpha-Si
3N
4, selecting nitriding temperature is 1350 ℃.
3.5 nitridation time is to the influence of nitridation process
When the thinner adding proportion be 20%, when nitriding temperature is 1350 ℃, nitridation time to the influence of nitridation process shown in accompanying drawing 5.Along with the prolongation of nitridation time, free silicone content reduces gradually in the nitrogenize product, and the transformation efficiency of silicon increases gradually.Under 1350 ℃, behind the nitrogenize 10min, free silica is merely 0.7% in the nitrogenize product, and the transformation efficiency of silicon has arrived 98.6%, α-Si
3N
4Content reaches 95%.Therefore, prolong nitridation time, can obviously improve nitrogenization speed, help the carrying out of nitrogenizing reaction, but along with the prolongation of nitridation time, the β phase content also increases gradually in the nitrogenize product, therefore, for obtaining high content of alpha-Si
3N
4, select 10min proper.
3.6 the XRD analysis of silicon nitride
Gained silicon nitride product of the present invention is carried out XRD analysis, and visible from the XRD spectrum of accompanying drawing 6: contain small-amount free Si the sample, quantitatively the XRD analysis result shows α-Si in the product
3N
4Content greater than 95%.The combustion processes of silica flour in nitrogen belongs to the gas-permeable combustion mode, and so-called infiltration burning is meant that the gas-phase reaction agent is present in the hole of silica flour base, reaction beginning, the N in the hole
2After being consumed, insufficient N
2Must be transferred to reaction front from the space outside the silica flour base.The prerequisite that the infiltration burning is able to carry out is to avoid silica flour fusing, reunion.If the fusing of a large amount of silica flours, N
2Just can not in time be penetrated into Si-N
2Reaction front, thus cause reaction not exclusively.In fact, the method that adopt to add thinner both can reduce temperature of reaction, can guarantee that again silica flour in the reaction process is unlikely fusing and reunites and be the molten bath, thereby guarantee at lower N
2The combusting under pressure building-up reactions is able to fully carry out.
3.7 ball milling change of granularity
Grind the change of granularity of different time powder and see table 3.Can find out that from table 3 when vertical ball mill ground 5h, the granularity of powder had been reduced to the magnitude of about 0.7 μ m (0.696 μ m), the magnitude that causes 0.7 μ m just falls in later and 35h and small planet ball mill and major planets ball mill are respectively at 15h.Powder refine to 0.5 μ m submicron order, and vertical grinder need grind 15h, and small planet grinding machine and major planets grinding machine need grind the time about 30h and 50h respectively.The efficient of efficiency ratio vertical ball mill that planetary mills is described is much lower.With the increase of milling time, the fine size of powder is difficult to refinement again, even increases on the contrary along with milling time increases granularity during to (d50=0.5 μ m) left and right sides to a certain degree.This be since powder carefully to a certain degree taking place due to the agglomeration.
Table 3 grinds the granularity of different time powder
| 20 | 0.804 | ||
| 25 | 0.593 | ||
| 30 | 0.727 | ||
| 35 | 0.465 | 0.696 | |
| 40 | 0.731 | ||
| 50 | 0.763 | 0.468 | |
| 100 | 0.888 |
Repeatedly investigate conditions such as different steps temperature, nitrogen flow and furnace pressure to silicon nitride α in the sample mutually, β mutually and the influence of remaining silicone content, the result is as shown in table 4 below:
Product under table 4 different technology conditions is formed
| Sequence number | α-Dan Huagui (%) | Beta-silicon nitride (%) | Silicon (%) |
| 1 | ?74 | 25 | 1 |
| 2 | ?83 | 14 | 3 |
| 3 | ?77 | 22 | 2 |
| 4 | ?84 | 14 | 2 |
| 5 | ?79 | 20 | 1 |
| 6 | ?89.4 | 9.1 | 0.5 |
| 7 | ?94.4 | 5.1 | 0.4 |
| 8 | ?97.6 | 2.1 | 0.3 |
| 9 | ?95.2 | 4.6 | 0.4 |
| 10 | ?96.4 | 3.2 | 0.4 |
Confirm relatively that processing condition of the present invention are: (1) at first through mechanical activation mode pre-treatment silica flour, makes raw material silica flour refinement and decrystallized, thereby improves solid state reaction agent activity, strengthens Si-N
2Between the reaction of gas-solid phase interface, improve Si-N under low nitrogen temperature and the low pressure
2The heat release combustion velocity.During grinding, the silicon nitride ball milling of 3 times of polymethyl acrylic acid and silica flour weight that adds water, the silica flour weight 0.2% of silica flour weight 90% is situated between, and prepares abrasive material.
(2) add α-Si
3N
4With nano amorphous Si
3N
4Mixing prevents silica flour from sintering as thinner, and the while is as the nucleus of resultant; Silica flour and mixing diluents is even.Composite thinning agent α-Si
3N
4With nano amorphous Si
3N
4Weight ratio is 1: 1; The composite thinning agent addition is 20% of a silica flour weight.
(3) dry silica flour and thinner under the nitrogen protection atmosphere under the normal pressure, feed nitrogen with certain flow, displace furnace air; Be heated to 1350 ℃ then, slowly rotate burner, prevent that on the one hand the silica flour bonding wall and the nitrogenize product that melt from luming, can material be disperseed on the other hand, the reinforcement silica flour contacts with nitrogen, and silica flour and nitrogen are fully reacted.
(4) be cooled to room temperature after, put into and be embedded with teflon-lined ball grinder or nylon jar and grind synthetic Si
3N
4Powder: add Si
3N
4The water of weight 90%, Si
3N
4The polymethyl acrylic acid of weight 0.2% and Si
3N
4The silicon nitride ball milling that weight is 3 times is situated between, and grinds synthetic Si
3N
4Powder.After grinding 5-15h, the size range of powder is at 0.696 μ m-0.515 μ m.Sieve filtering mill of slurry is situated between, grinds lumps after the oven dry after sieve.
Under above-mentioned optimum process condition, carry out multiple batches of middle experiment altogether.Pilot product is carried out to branch relatively with external expensive goods product, and data are as shown in table 5:
Table 5 representative sample both at home and abroad compares
| Sample | α-Dan Huagui (%) | Beta-silicon nitride (%) | Silicon (%) |
| Product of the present invention | ?97.6 | ?2.1 | 0.3 |
| Japan | ?97.1 | ?2.9 | 0 |
The silicon nitride product that adopts technology of the present invention to make is suitable with external like product quality.Therefrom select a batch products and carried out sreen analysis: granularity is with MICROTRACX100 particle size analyzer (U.S.) check and analysis appearance, and the result sees accompanying drawing 7.
Can know that from the sreen analysis report its volume average particle size D (4,3) is 1.591 microns, surface-area median size D (3,2) is 0.128 micron, and its main distributed areas are between 0.04 to 0.3 micron.
To product characterize comprehensively the result; The submicron that the present invention produces, micron silicon nitride have good purity and crystallinity; Characteristics such as density is big and thermal expansivity is little, hardness is big, Young's modulus is high and thermostability, chemicalstability and electrical insulating property be good; Can the body pottery or two kinds of forms of ceramic matric composite be widely used in industries such as metallurgy, space flight, aviation, petrochemical complex, machinery, electronics, can substitute external product fully.The submicron that the present invention produces, micron silicon nitride are applied to ceramic field and have intensity height, good, the strong characteristics of workability of snappiness, good market prospects.
Claims (4)
1. the working method of a high content of alpha crystalline form alpha-silicon nitride powders is characterized in that, realizes through following steps:
(1) at first through mechanical activation mode pre-treatment silica flour; The silicon nitride ball milling of 3 times of polymethyl acrylic acid and silica flour weight that adds water, the silica flour weight 0.2% of silica flour weight 90% during grinding is situated between, and prepares abrasive material;
(2) add α-Si
3N
4With nano amorphous Si
3N
4Composite thinning agent is with silica flour and thinner α-Si
3N
4Mix; The composite thinning agent addition is 20% of a silica flour weight;
(3) dry silica flour and composite thinning agent under the nitrogen protection under the normal pressure, feed nitrogen with certain flow, displace furnace air; Be heated to 1350 ℃ then, slowly rotate burner, silica flour and nitrogen are fully reacted, nitridation time is 15min;
(4) be cooled to room temperature after, put into and be embedded with teflon-lined ball grinder or nylon jar and grind synthetic Si
3N
4Powder: add Si
3N
4The water of weight 90%, Si
3N
4The polymethyl acrylic acid of weight 0.2% and Si
3N
4The silicon nitride ball milling that weight is 3 times is situated between, and grinds synthetic Si
3N
4Powder; The filtering of then sieving mill is situated between, and grinds lumps after the oven dry after sieve.
2. the working method of alpha-silicon nitride powders as claimed in claim 1 is characterized in that, composite thinning agent α-Si
3N
4With nano amorphous Si
3N
4Weight ratio is 1: 1.
3. according to claim 1 or claim 2 the working method of alpha-silicon nitride powders is characterized in that, adopts vertical lapping machine mechanical activation silica flour 8h; Adopt vertical lapping machine to grind Si
3N
4Powder 7-10h.
4. according to claim 1 or claim 2 the working method of alpha-silicon nitride powders is characterized in that used type of heating adopts the gradient temperature-programmed mode to carry out through microcomputerized control.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201110025965A CN102173396B (en) | 2011-01-25 | 2011-01-25 | Production method of high-content alpha-crystal form silicon nitride powders |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201110025965A CN102173396B (en) | 2011-01-25 | 2011-01-25 | Production method of high-content alpha-crystal form silicon nitride powders |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102173396A CN102173396A (en) | 2011-09-07 |
| CN102173396B true CN102173396B (en) | 2012-10-24 |
Family
ID=44516704
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201110025965A Expired - Fee Related CN102173396B (en) | 2011-01-25 | 2011-01-25 | Production method of high-content alpha-crystal form silicon nitride powders |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102173396B (en) |
Families Citing this family (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102807196B (en) * | 2012-08-26 | 2013-12-25 | 西安科技大学 | Method for preparing silicon nitride nano material |
| CN104495765B (en) * | 2014-12-09 | 2016-11-30 | 浙江大学 | A kind of method utilizing porous silicon to prepare alpha-phase silicon nitride |
| CN104528672A (en) * | 2014-12-17 | 2015-04-22 | 青岛桥海陶瓷新材料科技有限公司 | Preparation method of alpha-silicon nitride |
| CN105480957A (en) * | 2016-01-18 | 2016-04-13 | 沈阳工业大学 | Method for preparing non-grinding high-purity fully granulated silicon nitride powder by adopting direct nitriding method |
| CN105884374B (en) * | 2016-06-15 | 2018-10-30 | 杭州硅诺科技有限公司 | A method of preparing super alpha-phase silicon nitride using nano-tube |
| CN107698264A (en) * | 2016-08-09 | 2018-02-16 | 河北高富氮化硅材料有限公司 | A kind of preparation method of modified alpha-phase silicon nitride powder |
| CN107285288A (en) * | 2017-07-12 | 2017-10-24 | 深圳市东川技术研究有限公司 | The preparation method of nano silicon nitride powders |
| CN110357050B (en) * | 2019-07-03 | 2023-03-24 | 南昌大学 | Preparation method of equiaxed beta-phase silicon nitride powder |
| CN115432676B (en) * | 2021-06-04 | 2024-03-26 | 中国科学院过程工程研究所 | System and method for preparing high-quality silicon nitride powder by multistage fluidized bed |
| CN113563088B (en) * | 2021-07-30 | 2023-06-13 | 淄博国创中心先进车用材料技术创新中心 | Porous silicon nitride ceramic part and manufacturing method thereof |
| CN114790107B (en) * | 2022-04-29 | 2023-05-09 | 江苏大学 | SiO preparation at low temperature by using polycrystalline silicon cutting waste 2 -Si 3 N 4 Method for compounding ceramic |
| CN116216662B (en) * | 2023-02-01 | 2023-10-27 | 江苏富乐华功率半导体研究院有限公司 | Synthesis method of silicon nitride powder |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4604273A (en) * | 1985-04-19 | 1986-08-05 | Gte Products Corporation | Process for the growth of alpha silicon nitride whiskers |
| CN1362358A (en) * | 2002-01-22 | 2002-08-07 | 清华大学 | Low pressure combustion process of synthesizing alpha-phase silicon nitride powder |
| CN1424249A (en) * | 2002-12-26 | 2003-06-18 | 北京科技大学 | Method and apparatus for producing silicon nitride or ferro silicon nitride by low pressure combustion |
| CN1696076A (en) * | 2004-05-11 | 2005-11-16 | 中国科学院理化技术研究所 | Temperature controlled combustion method for synthesizing powder of silicon nitride in alpha phase |
-
2011
- 2011-01-25 CN CN201110025965A patent/CN102173396B/en not_active Expired - Fee Related
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4604273A (en) * | 1985-04-19 | 1986-08-05 | Gte Products Corporation | Process for the growth of alpha silicon nitride whiskers |
| CN1362358A (en) * | 2002-01-22 | 2002-08-07 | 清华大学 | Low pressure combustion process of synthesizing alpha-phase silicon nitride powder |
| CN1424249A (en) * | 2002-12-26 | 2003-06-18 | 北京科技大学 | Method and apparatus for producing silicon nitride or ferro silicon nitride by low pressure combustion |
| CN1696076A (en) * | 2004-05-11 | 2005-11-16 | 中国科学院理化技术研究所 | Temperature controlled combustion method for synthesizing powder of silicon nitride in alpha phase |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102173396A (en) | 2011-09-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102173396B (en) | Production method of high-content alpha-crystal form silicon nitride powders | |
| CN102173397B (en) | Production method of high-content silicon nitride (Si3N4) powder | |
| CN105777124B (en) | A kind of preparation method of graphene growth in situ silicon carbide nano material | |
| CN100497762C (en) | Method for preparing mullite crystal whisker from coal refuse and aluminum oxide | |
| CN101798223B (en) | Preparation method of compact silicon carbide ceramic | |
| CN100493691C (en) | Dissolvent hot liquid state phase-change method for synthesizing superhard micro nano material | |
| CN101580236B (en) | Method for preparing boron nitride nanotubes by annealing of inorganic boracic precursor | |
| CN102432296A (en) | Comprehensive treatment technology of waste mortar in processing of photovoltaic crystalline silicon | |
| CN105272269A (en) | Preparation method of Si3N4/h-BN nano-composite ceramics | |
| CN103979507A (en) | Method for preparing spherical aluminum nitride powder under assistance of high atmospheric pressure and fluoride additive | |
| CN1362358A (en) | Low pressure combustion process of synthesizing alpha-phase silicon nitride powder | |
| CN103641484A (en) | Method for preparing Si3N4/SiC composite ceramic powder from biomass power plant ash | |
| CN102807370A (en) | Method for rapidly preparing AlON ceramic powder by means of carbon thermal reduction | |
| CN101428771A (en) | Method for producing A1Npowder with microwave carbon thermoreduction cooling-down catalysis calcination | |
| CN104671795B (en) | A kind of single-phase α-Si3n4superfine powder and preparation method thereof | |
| CN111115592B (en) | Preparation method of nano silicon nitride powder | |
| CN103159190B (en) | A kind of superpure nitrogen compound raw powder's production technology | |
| CN101863663A (en) | Combustion method for preparing submicron grade titanium carbide polycrystal powder | |
| CN101786884A (en) | Preparation method of boron nitride nano-tube | |
| JP2005194154A (en) | Sialon sintered compact | |
| CN101376494B (en) | Method for preparing aluminum nitride powder by room temperature mechanical ball milling induction solid state reaction | |
| CN112694336B (en) | Preparation method of high-purity alpha-phase silicon nitride fibrofelt | |
| CN101224878A (en) | Ball-milling preparation method of cubic-phase nano zirconium nitride | |
| TW201925082A (en) | A method for producing spherical silicon nitride powder using carbothermal reduction nitridation reaction to reduce an occurrence of excessive carbon residues | |
| Ishihara et al. | Synthesis of silicon carbide powders from fumed silica powder and phenolic resin |
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 | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20121024 Termination date: 20130125 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |