CN112222418B - Method for preparing nano tungsten powder by regulating nucleation and growth processes and application - Google Patents
Method for preparing nano tungsten powder by regulating nucleation and growth processes and application Download PDFInfo
- Publication number
- CN112222418B CN112222418B CN202011413644.5A CN202011413644A CN112222418B CN 112222418 B CN112222418 B CN 112222418B CN 202011413644 A CN202011413644 A CN 202011413644A CN 112222418 B CN112222418 B CN 112222418B
- Authority
- CN
- China
- Prior art keywords
- tungsten
- nano
- powder
- tungsten powder
- nucleation
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 title claims abstract description 119
- 238000000034 method Methods 0.000 title claims abstract description 65
- 230000008569 process Effects 0.000 title claims abstract description 34
- 230000006911 nucleation Effects 0.000 title claims abstract description 30
- 238000010899 nucleation Methods 0.000 title claims abstract description 30
- 230000001105 regulatory effect Effects 0.000 title claims abstract description 19
- ZNOKGRXACCSDPY-UHFFFAOYSA-N tungsten trioxide Chemical compound O=[W](=O)=O ZNOKGRXACCSDPY-UHFFFAOYSA-N 0.000 claims abstract description 80
- 239000011852 carbon nanoparticle Substances 0.000 claims abstract description 67
- 230000009467 reduction Effects 0.000 claims abstract description 42
- 229910052721 tungsten Inorganic materials 0.000 claims abstract description 38
- 239000010937 tungsten Substances 0.000 claims abstract description 38
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims abstract description 36
- 239000001257 hydrogen Substances 0.000 claims abstract description 36
- 229910052739 hydrogen Inorganic materials 0.000 claims abstract description 36
- 239000000203 mixture Substances 0.000 claims abstract description 33
- 239000000843 powder Substances 0.000 claims abstract description 27
- 239000002131 composite material Substances 0.000 claims abstract description 21
- 239000000956 alloy Substances 0.000 claims abstract description 10
- 230000001276 controlling effect Effects 0.000 claims abstract description 9
- 229910045601 alloy Inorganic materials 0.000 claims abstract description 8
- UONOETXJSWQNOL-UHFFFAOYSA-N tungsten carbide Chemical compound [W+]#[C-] UONOETXJSWQNOL-UHFFFAOYSA-N 0.000 claims abstract description 5
- DZKDPOPGYFUOGI-UHFFFAOYSA-N tungsten(iv) oxide Chemical compound O=[W]=O DZKDPOPGYFUOGI-UHFFFAOYSA-N 0.000 claims description 49
- 239000002245 particle Substances 0.000 claims description 36
- 239000000463 material Substances 0.000 claims description 27
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 26
- 239000002270 dispersing agent Substances 0.000 claims description 24
- 239000012298 atmosphere Substances 0.000 claims description 20
- 238000003756 stirring Methods 0.000 claims description 20
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 11
- 229910052799 carbon Inorganic materials 0.000 claims description 11
- 238000000498 ball milling Methods 0.000 claims description 9
- 238000001704 evaporation Methods 0.000 claims description 8
- 238000000227 grinding Methods 0.000 claims description 6
- 238000002604 ultrasonography Methods 0.000 claims 2
- 238000002360 preparation method Methods 0.000 abstract description 12
- 238000002156 mixing Methods 0.000 abstract description 6
- 238000004519 manufacturing process Methods 0.000 abstract description 5
- 238000003763 carbonization Methods 0.000 abstract description 2
- 238000005245 sintering Methods 0.000 abstract description 2
- 239000002667 nucleating agent Substances 0.000 description 13
- 229920001223 polyethylene glycol Polymers 0.000 description 12
- 239000002159 nanocrystal Substances 0.000 description 11
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 6
- 239000003638 chemical reducing agent Substances 0.000 description 6
- 229920002523 polyethylene Glycol 1000 Polymers 0.000 description 6
- 239000002994 raw material Substances 0.000 description 5
- 239000012798 spherical particle Substances 0.000 description 5
- 238000004663 powder metallurgy Methods 0.000 description 4
- 238000001132 ultrasonic dispersion Methods 0.000 description 4
- 238000005054 agglomeration Methods 0.000 description 3
- 230000002776 aggregation Effects 0.000 description 3
- 239000012300 argon atmosphere Substances 0.000 description 3
- 238000011161 development Methods 0.000 description 3
- 239000010419 fine particle Substances 0.000 description 3
- 239000007789 gas Substances 0.000 description 3
- 239000002086 nanomaterial Substances 0.000 description 3
- 238000011946 reduction process Methods 0.000 description 3
- 238000001878 scanning electron micrograph Methods 0.000 description 3
- 229910001080 W alloy Inorganic materials 0.000 description 2
- 230000033228 biological regulation Effects 0.000 description 2
- 238000004581 coalescence Methods 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 241001391944 Commicarpus scandens Species 0.000 description 1
- 229910000881 Cu alloy Inorganic materials 0.000 description 1
- 229910003271 Ni-Fe Inorganic materials 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 238000005229 chemical vapour deposition Methods 0.000 description 1
- 239000000306 component Substances 0.000 description 1
- 239000008358 core component Substances 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000007123 defense Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 238000004880 explosion Methods 0.000 description 1
- 230000004927 fusion Effects 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 238000009776 industrial production Methods 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000005012 migration Effects 0.000 description 1
- 238000013508 migration Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 239000004570 mortar (masonry) Substances 0.000 description 1
- 239000002105 nanoparticle Substances 0.000 description 1
- 239000011858 nanopowder Substances 0.000 description 1
- QGLKJKCYBOYXKC-UHFFFAOYSA-N nonaoxidotritungsten Chemical compound O=[W]1(=O)O[W](=O)(=O)O[W](=O)(=O)O1 QGLKJKCYBOYXKC-UHFFFAOYSA-N 0.000 description 1
- 238000005240 physical vapour deposition Methods 0.000 description 1
- 239000002243 precursor Substances 0.000 description 1
- 238000004321 preservation Methods 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 239000012495 reaction gas Substances 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 238000013341 scale-up Methods 0.000 description 1
- 238000004544 sputter deposition Methods 0.000 description 1
- 229910001930 tungsten oxide Inorganic materials 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F9/00—Making metallic powder or suspensions thereof
- B22F9/16—Making metallic powder or suspensions thereof using chemical processes
- B22F9/18—Making metallic powder or suspensions thereof using chemical processes with reduction of metal compounds
- B22F9/20—Making metallic powder or suspensions thereof using chemical processes with reduction of metal compounds starting from solid metal compounds
- B22F9/22—Making metallic powder or suspensions thereof using chemical processes with reduction of metal compounds starting from solid metal compounds using gaseous reductors
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
- B22F3/10—Sintering only
- B22F3/1003—Use of special medium during sintering, e.g. sintering aid
- B22F3/1007—Atmosphere
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
- B22F3/10—Sintering only
- B22F3/105—Sintering only by using electric current other than for infrared radiant energy, laser radiation or plasma ; by ultrasonic bonding
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y40/00—Manufacture or treatment of nanostructures
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B32/00—Carbon; Compounds thereof
- C01B32/90—Carbides
- C01B32/914—Carbides of single elements
- C01B32/949—Tungsten or molybdenum carbides
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
- B22F3/10—Sintering only
- B22F3/105—Sintering only by using electric current other than for infrared radiant energy, laser radiation or plasma ; by ultrasonic bonding
- B22F2003/1051—Sintering only by using electric current other than for infrared radiant energy, laser radiation or plasma ; by ultrasonic bonding by electric discharge
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/60—Particles characterised by their size
- C01P2004/64—Nanometer sized, i.e. from 1-100 nanometer
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Organic Chemistry (AREA)
- Mechanical Engineering (AREA)
- Physics & Mathematics (AREA)
- Nanotechnology (AREA)
- Optics & Photonics (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Inorganic Chemistry (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Crystallography & Structural Chemistry (AREA)
- Manufacture Of Metal Powder And Suspensions Thereof (AREA)
Abstract
The invention discloses a method for preparing nano tungsten powder by regulating nucleation and growth processes, which comprises the following steps: firstly, crushing and dispersing nanocrystalline tungsten trioxide, and then uniformly mixing the tungsten trioxide with carbon nano particles to obtain composite powder; secondly, performing primary hydrogen reduction on the composite powder to obtain a mixture; thirdly, performing two-stage reduction on the mixture to obtain nano tungsten powder; the invention also discloses the application of the nano tungsten powder in the preparation of fine-grain/ultra-fine-grain tungsten-based alloy by sintering and the preparation of ultra-fine/nano tungsten carbide powder by carbonization. The method effectively regulates and controls WO by adjusting the mixing degree of the nanocrystalline tungsten trioxide and the carbon nanoparticles and controlling the conditions of first-stage hydrogen reduction and second-stage reduction3The W is reduced to the nucleation and growth process, the nucleation rate of the tungsten is improved, the granularity of the tungsten powder is reduced, the growth of the tungsten powder is promoted, the process is simple, the cost is lower, and the method is suitable for large-scale industrialized production of the nano tungsten powder; the invention has wide application range, effectively improves the density of the tungsten-based alloy and improves the performance of the tungsten-based alloy.
Description
Technical Field
The invention belongs to the technical field of preparation of nano powder materials, and particularly relates to a method for preparing nano tungsten powder by regulating nucleation and growth processes and application.
Background
Metallic tungsten has many very excellent properties, such as: high melting point (3410 ℃), high-temperature strength, elastic modulus, electric conductivity, thermal conductivity and corrosion resistance, small expansion coefficient, vapor pressure and evaporation rate, high sputtering threshold value, low H/He retention and the like. Therefore, tungsten and its alloy materials have very critical applications in many fields such as nuclear industry, aerospace, military industry, electronics and electrical industry, chemical industry and metallurgical industry. For example: tungsten-based materials are considered as the most promising candidate materials for plasma-facing first walls and divertors in future nuclear fusion devices; the W-Cu alloy is applied to electrical contact materials of core components of various high-voltage circuit breakers; heavy tungsten alloys (W-Ni-Fe/Cu) are used for armor piercing weapons and radiation shielding materials. With the rapid development of the application industry, the tungsten material with a common structure is difficult to meet the urgent requirements of civil and military industry and national defense fields on the superior comprehensive performance of the tungsten material. The design and preparation of the ultra-fine grain/nano-structure tungsten material are considered as important ways for obtaining the powder metallurgy tungsten-based material with excellent comprehensive performance, and are an important development trend of the tungsten powder metallurgy material.
The high-quality nano tungsten powder is a key raw material for preparing ultra-fine grain/nano structure tungsten and alloy materials thereof by powder metallurgy. Due to the excellent characteristics and important application of nano tungsten powder, the preparation of nano tungsten powder has been a hot point of domestic and foreign research in the past decade, and many researchers have developed numerous methods for preparing nano tungsten powder, such as: mechanical ball milling, chemical/physical vapor deposition, thermal plasma hydrogen reduction, wire electrical explosion, low temperature molten salt, nanometer tungsten oxide precursor hydrogen reduction, and the like. Although the methods can prepare the nano tungsten powder, many of the methods are limited by high cost, complex process, low production efficiency, poor powder performance, production safety or difficulty in scale-up production and the like, and are still in experimental exploration and development stages, and difficult to be used for engineering/commercial production of the nano tungsten powder. At present, the low cost, high efficiency and engineered preparation of nano (doped) tungsten powder is still a difficult problem and becomes a bottleneck link of the commercial preparation and application of powder metallurgy ultra-fine grain/nano structure tungsten alloy.
In the process of preparing tungsten powder by industrialized tungsten trioxide through hydrogen reduction, the material layer is thick, so that the gas-phase hydrate WO2(OH)2The prepared tungsten powder has larger granularity, usually micron-sized, and the formed tungsten powder has less nucleation quantity. In the traditional process of reducing tungsten trioxide by carbon, WO is not contained in gas phase hydrate2(OH)2But the reaction temperature is higher and the nucleation quantity is less, resulting in the prepared WO2The particle size also reaches several micrometers, which makes it difficult to prepare nano tungsten powder with uniform particle size.
Disclosure of Invention
The technical problem to be solved by the invention is to provide a method for preparing nano tungsten powder by regulating and controlling nucleation and growth processes aiming at the defects of the prior art. The method comprises the steps of sequentially carrying out primary hydrogen reduction and secondary reduction by taking nanocrystalline tungsten trioxide as a raw material, adjusting the mixing degree of the nanocrystalline tungsten trioxide and carbon nanoparticles, taking the carbon nanoparticles as a nucleating agent and controlling the hydrogen reduction temperature in the primary hydrogen reduction, and taking the carbon nanoparticles as a reducing agent and the nucleating agent and controlling the reduction temperature in the secondary reduction, thereby effectively regulating and controlling WO3And the W is reduced to the nucleation and growth process, so that the nucleation rate of the tungsten is obviously improved, the granularity of the tungsten powder is effectively reduced, and the growth of the nano tungsten powder is promoted.
In order to solve the technical problems, the invention adopts the technical scheme that: a method for preparing nano tungsten powder by regulating nucleation and growth processes is characterized by comprising the following steps:
step one, crushing and dispersing nanocrystalline tungsten trioxide, ultrasonically dispersing the crushed and dispersed nanocrystalline tungsten trioxide and carbon nanoparticles in an ethanol solution with the aid of a dispersing agent, stirring at room temperature, and stirring and evaporating to dryness to obtain composite powder;
the stirring time at room temperature is 0.5-4 h; the temperature for stirring and drying is 60-80 ℃;
step two, laying the composite powder obtained in the step one, reacting for 1-4 h at 550-640 ℃ in a hydrogen atmosphere, and carrying out primary hydrogen reduction to obtain a mixture; the mixture consists of carbon nano-particles and superfine/nano-tungsten dioxide, wherein the average particle size of the superfine/nano-tungsten dioxide is 100 nm-300 nm;
step three, laying the mixture obtained in the step two, and then preserving heat for 1-5 hours at 950-1050 ℃ for second-stage reduction to obtain nano tungsten powder; the average particle size of the nano tungsten powder is 20 nm-100 nm.
According to the invention, the nano-crystal tungsten trioxide which has a relatively high specific surface area and is easy to break and disperse is used as a raw material, and a dispersing agent and an ultrasonic dispersion method are combined, so that the broken and dispersed nano-crystal tungsten trioxide is uniformly mixed with carbon nano-particles to obtain composite powder, the agglomeration of the carbon nano-particles is avoided, and the nano-crystal tungsten trioxide is beneficial to obtaining nano-tungsten powder with uniform particle size and components; then laying the composite powder, and then carrying out primary hydrogen reduction, wherein the reduction temperature is 400-600 ℃ lower than the traditional carbon reduction temperature, so that the tungsten trioxide is reduced into tungsten dioxide, the carbon nanoparticles in the composite powder are used as a nucleating agent in the reduction process, so that higher porosity is provided, the nucleation number of the tungsten dioxide is increased, the granularity of the tungsten dioxide is effectively reduced, better dispersity is obtained, the control on the granularity and the dispersity of the tungsten dioxide is realized, and a mixture consisting of the carbon nanoparticles and the superfine/nano tungsten dioxide is obtained; and continuously laying the mixture, then carrying out secondary reduction, taking the carbon nano particles as a reducing agent and a nucleating agent, and reducing the superfine/nano tungsten dioxide in the mixture into tungsten powder at the reduction temperature of 950-1050 ℃, wherein in the reduction process, the nucleating agent with finer granularity obviously improves the nucleation number, the porosity of the tungsten dioxide with finer granularity and the carbon nano particles is higher, the dispersity and the uniformity are excellent, and the coalescence growth among the tungsten powder particles is effectively prevented, so that the nano tungsten powder is obtained.
The method for preparing the nano tungsten powder by regulating nucleation and growth processes is characterized in that in the step one, the nano-crystalline tungsten trioxide is nano-crystalline yellow tungsten or nano-crystalline blue tungsten, the average grain size of the nano-crystalline tungsten trioxide is 40-150 nm, and the specific surface area is 7g/cm3~14g/cm3(ii) a The average particle size of the carbon nanoparticles in the step one is5nm to 80nm, and the specific surface area is 70g/cm3~500g/cm3The carbon content in the carbon nano particles is more than 99%, and the mass of the carbon nano particles is 9.2-10.5% of the mass of the nano-crystalline tungsten trioxide after crushing and dispersing. The nano-crystalline tungsten trioxide of the preferred kind is easier to break and disperse and easier to mix with carbon nano-particles; and preferably, the carbon nanoparticles have a fine particle size and a large specific surface area, thereby having excellent dispersibility, and are used as WO3Reduction to WO2The nucleating agent in the process obviously improves WO2And reducing WO2The particle size of the particles further obtains the nano tungsten powder, so that the preparation method of the invention is obviously superior to the traditional carbon reduction method.
The method for preparing the nano tungsten powder by regulating the nucleation and growth processes is characterized in that in the step one, the crushing and dispersing mode is one or more of grinding, ball milling and ultrasonic, and the crushing and dispersing time is 0.5-5 h. The raw materials adopted by the invention are various in crushing and dispersing modes, so that the applicability of the invention is improved; the optimal crushing and dispersing time ensures that the nanocrystalline tungsten trioxide is fully and uniformly crushed, improves the preparation efficiency and avoids introducing impurities due to overlong crushing and dispersing time.
The method for preparing the nano tungsten powder by regulating the nucleation and growth processes is characterized in that in the step one, the dispersing agent is one or more than two of PEG, PVP and PVA, and the adding mass of the dispersing agent is 0.2-1.2% of the total mass of the carbon nano particles and the nano-crystal tungsten trioxide after crushing and dispersing. The preferable dispersing agent and the added mass further avoid the agglomeration of the carbon nano-particles and improve the mixing uniformity of the nucleating agent carbon nano-particles and the nano-crystal tungsten trioxide after crushing and dispersing.
The method for preparing the nano tungsten powder by regulating the nucleation and growth processes is characterized in that in the step one, the stirring time at room temperature is 0.5-4 hours; the temperature for stirring and evaporating to dryness is 60-80 ℃.
The method for preparing the nano tungsten powder by regulating the nucleation and growth processes is characterized in that in the second step, the thickness of a material layer laid by the composite powder is 5-30 mm, and the dew point of a hydrogen atmosphere is less than-40 ℃; in the third step, the thickness of the material layer after the mixture is laid is 5 mm-30 mm, and the atmosphere adopted by the second-stage reduction is vacuum or inert atmosphere. The optimal thickness of the laid material layer and the corresponding process parameters ensure that reaction gas and product gas are easy to diffuse into the material layer, the reduction efficiency is improved, and simultaneously the gas phase migration rate of a tungsten source is ensured, so that the nucleation and particle size regulation effects of carbon nanoparticles are exerted, and products with uniform particle sizes and distribution are obtained.
In addition, the invention also provides application of the nano tungsten powder prepared by the method, which is characterized in that the nano tungsten powder is sintered to prepare fine-grain/ultra-fine-grain tungsten-based alloy, or the nano tungsten powder is carbonized to prepare ultra-fine/nano tungsten carbide powder.
Compared with the prior art, the invention has the following advantages:
1. the method takes the nanocrystalline tungsten trioxide as a raw material to carry out primary hydrogen reduction and secondary reduction in sequence, and effectively regulates and controls WO (tungsten trioxide) by adjusting the uniform mixing degree of the nanocrystalline tungsten trioxide and the carbon nanoparticles, taking the carbon nanoparticles as a nucleating agent and controlling the hydrogen reduction temperature in the primary hydrogen reduction and taking the carbon nanoparticles as a reducing agent and the nucleating agent and controlling the reduction temperature in the secondary reduction3And (3) the W is reduced to the nucleation and growth process, so that the nucleation rate of the tungsten is obviously improved, the granularity of the tungsten powder is effectively reduced, the growth of the tungsten powder is promoted, and the nano tungsten powder is finally obtained.
2. According to the invention, the carbon nanoparticles with low cost and excellent dispersibility are respectively used as the nucleating agent and the reducing agent in the two-step reduction process, and the dispersing agent is used for assisting ultrasonic dispersion, so that the problems of agglomeration of the carbon nanoparticles and difficulty in uniform mixing of nanocrystalline tungsten trioxide and the carbon nanoparticles due to size difference are solved, and the nano tungsten powder is favorably obtained.
3. The invention adopts carbon nano-particles with fine particle size and excellent dispersibility as WO3Reduction to WO2The nucleating agent in the process obviously improves WO2And reducing WO2The particle size of the particles is further used for obtaining the nano tungsten powder, so that the preparation method of the invention is obviously superior to the traditional hydrogen reduction and carbon reduction。
4. The invention adopts carbon nano-particles as WO2The reducing agent and the nucleating agent in the process of reducing the tungsten powder are reduced, the nucleating quantity is obviously improved, the porosity between the nucleating agent with fine granularity and the carbon nano-particle reducing agent is higher, and the coalescence growth among tungsten powder particles is effectively prevented, so that the nano tungsten powder is obtained.
5. The invention is realized by combining WO3Reducing to nucleation and growth process of the tungsten powder, preparing the nano tungsten powder with average particle size of 20 nm-100 nm, and having simple process, good particle size regulation effect and lower cost, thus being suitable for large-scale industrial production of the nano tungsten powder.
6. The nano tungsten powder is applied to sintering preparation of fine-grain/ultra-fine-grain tungsten-based alloy and carbonization preparation of ultra-fine/nano tungsten carbide powder, has a wide application range, effectively improves the density of the tungsten-based alloy and improves the performance of the tungsten-based alloy.
The technical solution of the present invention is further described in detail by the accompanying drawings and examples.
Drawings
FIG. 1 is an SEM photograph of a mixture prepared in example 1 of the present invention.
Fig. 2 is an SEM image of the nano tungsten powder prepared in example 1 of the present invention.
Detailed Description
The method for preparing the nano tungsten powder by regulating the nucleation and growth processes is described in detail through the embodiments 1 to 5.
Example 1
The embodiment comprises the following steps:
step one, taking an ethanol solution as a ball milling medium, performing low-energy ball milling for 2 hours at a rotating speed of 200 r/min for crushing and dispersing nano-crystalline tungsten trioxide with a loose structure, performing ultrasonic dispersion on the nano-crystalline tungsten trioxide and carbon nano-particles in the ethanol solution under the assistance of a dispersing agent PVP, stirring for 2 hours at room temperature, and stirring and evaporating at 70 ℃ to dryness to obtain composite powder;
the mass purity of the nanocrystalline tungsten trioxide is 99.9 percent, the average grain size is 95nm, and the specific surface area is 7.5g/cm3；
The carbonThe nanoparticles are approximately spherical particles, the average particle size is 20nm, and the specific surface area is 155g/cm3The carbon content in the carbon nano particles is 99.9 percent, and the mass of the carbon nano particles is 9.8 percent of the mass of the nano-crystalline tungsten trioxide after crushing and dispersing;
the adding mass of the dispersing agent PVP is 0.3 percent of the total mass of the carbon nano-particles and the nano-crystal tungsten trioxide after crushing and dispersing;
step two, laying the composite powder obtained in the step one until the thickness of a material layer is 12mm, and then reacting for 1.5h in a hydrogen atmosphere at 580 ℃ to perform primary hydrogen reduction to obtain a mixture; the dew point of the hydrogen atmosphere is less than-40 ℃, the mixture consists of carbon nano-particles and superfine/nano tungsten dioxide, wherein the average particle size of the superfine/nano tungsten dioxide is 150 nm;
step three, paving the mixture obtained in the step two until the thickness of a material layer is 12mm, and then preserving heat for 2 hours in an argon atmosphere at 1020 ℃ for second-stage reduction to obtain nano tungsten powder; the average particle size of the nano tungsten powder is 30 nm.
Fig. 1 is an SEM image of the mixture prepared in this example, and it can be seen from fig. 1 that the particle size of the mixture is fine and the dispersibility is good.
Fig. 2 is an SEM image of the nano tungsten powder prepared in this example, and it can be seen from fig. 2 that the nano tungsten powder prepared in this example has a fine particle size, and the average particle size is about 30 nm.
The dispersant in this embodiment may be one or two or more of PEG, PVP, and PVA other than PVP.
Example 2
The embodiment comprises the following steps:
step one, preparing nanocrystalline blue tungsten WO with a loose structure2.9Grinding in an agate mortar for 1h, ultrasonically dispersing in an ethanol solution for 2h, then ultrasonically dispersing with carbon nanoparticles in the ethanol solution with the aid of a dispersing agent PEG-1000, stirring at room temperature for 1.5h, and stirring at 80 ℃ until dried to obtain a composite powder;
the mass purity of the nano-crystal blue tungsten is 99.95 percent, the average grain size is 80nm, and the specific surface area is10g/cm3；
The carbon nano-particles are nearly spherical particles, the average particle size is 40nm, and the specific surface area is 95g/cm3The carbon content in the carbon nano-particles is 99.5 percent, and the mass of the carbon nano-particles is 10.2 percent of that of the nano-crystalline blue tungsten after crushing and dispersing;
the added mass of the dispersing agent PEG-1000 is 0.5 percent of the total mass of the carbon nano-particles and the crushed and dispersed nano-crystal blue tungsten;
step two, laying the composite powder obtained in the step one until the thickness of a material layer is 15mm, and then reacting for 2 hours in a hydrogen atmosphere at 570 ℃ to perform primary hydrogen reduction to obtain a mixture; the dew point of the hydrogen atmosphere is less than-40 ℃, the mixture consists of carbon nano-particles and superfine/nano tungsten dioxide, wherein the average particle size of the superfine/nano tungsten dioxide is 206 nm;
step three, paving the mixture obtained in the step two until the thickness of a material layer is 15mm, and then preserving heat for 2 hours under the conditions of vacuum degree of 0.1Pa and temperature of 1000 ℃ to carry out two-stage reduction to obtain nano tungsten powder; the average particle size of the nano tungsten powder is 50 nm.
The dispersant in this embodiment may be one or two or more of PEG, PVP, and PVA other than PEG-1000.
Example 3
The embodiment comprises the following steps:
step one, nanocrystalline yellow tungsten WO with loose structure3Ball-milling for 2h, ultrasonically dispersing for 0.5h in an ethanol solution medium, ultrasonically dispersing the mixture and carbon nanoparticles in the ethanol solution with the aid of a dispersing agent PEG-1000, stirring for 2h at room temperature, and stirring at 80 ℃ until the mixture is dried to obtain composite powder;
the mass purity of the nanocrystalline yellow tungsten is 99.9 percent, the average grain size is 96nm, and the specific surface area is 9.2g/cm3；
The carbon nano-particles are nearly spherical particles, the average particle size is 30nm, and the specific surface area is 127g/cm3The carbon content in the carbon nano particles is 99.5 percent, and the mass of the carbon nano particles is 10.1 percent of that of the nano crystal yellow tungsten after crushing and dispersing;
the added mass of the dispersing agent PEG-1000 is 0.3 percent of the total mass of the carbon nano-particles and the crushed and dispersed nano-crystalline yellow tungsten;
step two, laying the composite powder obtained in the step one until the thickness of a material layer is 18mm, and then reacting for 4 hours in a hydrogen atmosphere at 560 ℃ to perform primary hydrogen reduction to obtain a mixture; the dew point of the hydrogen atmosphere is less than minus 40 ℃, the mixture consists of carbon nano-particles and superfine/nano tungsten dioxide, wherein the average particle size of the superfine/nano tungsten dioxide is 184 nm;
step three, paving the mixture obtained in the step two until the thickness of a material layer is 12mm, and then preserving heat for 2 hours in an argon atmosphere at 1040 ℃ to perform two-stage reduction to obtain nano tungsten powder; the average particle size of the nano tungsten powder is 80 nm.
The dispersant in this embodiment may be one or two or more of PEG, PVP, and PVA other than PEG-1000.
Example 4
The embodiment comprises the following steps:
step one, preparing nanocrystalline blue tungsten WO with a loose structure2.9Grinding for 0.5h by taking an ethanol solution as a grinding medium, then ultrasonically dispersing the ethanol solution and carbon nano-particles in the ethanol solution under the assistance of dispersing agents PVP and PEG, stirring for 4h at room temperature, and stirring and evaporating at 60 ℃ to dryness to obtain composite powder;
the mass purity of the nanocrystalline blue tungsten is 99.9 percent, the average grain size is 40nm, and the specific surface area is 14g/cm3；
The carbon nano-particles are nearly spherical particles, the average particle size is 5nm, and the specific surface area is 500g/cm3The carbon content in the carbon nano-particles is 99.5 percent, and the mass of the carbon nano-particles is 9.2 percent of the mass of the nano-crystalline blue tungsten after crushing and dispersing;
the adding mass of the dispersing agents PVP and PEG is 1.2% of the total mass of the carbon nano-particles and the crushed and dispersed nano-crystal blue tungsten;
step two, laying the composite powder obtained in the step one until the thickness of a material layer is 5mm, and then reacting for 1h in a hydrogen atmosphere at 550 ℃ to perform primary hydrogen reduction to obtain a mixture; the dew point of the hydrogen atmosphere is less than-40 ℃, the mixture consists of carbon nano-particles and superfine/nano tungsten dioxide, wherein the average particle size of the superfine/nano tungsten dioxide is 100 nm;
step three, paving the mixture obtained in the step two until the thickness of a material layer is 5mm, and then preserving heat for 5 hours in an argon atmosphere at 950 ℃ to perform two-stage reduction to obtain nano tungsten powder; the average particle size of the nano tungsten powder is 20 nm.
The dispersant in this embodiment may also be one or two or more of PEG, PVP, and PVA in addition to PVP and PEG combinations.
Example 5
The embodiment comprises the following steps:
step one, taking an ethanol solution as a ball milling medium, performing low-energy ball milling for 5 hours at a rotating speed of 150 revolutions per minute for crushing and dispersing, then performing ultrasonic dispersion on carbon nanoparticles and the ethanol solution with the aid of a dispersing agent PEG, stirring for 0.5 hour at room temperature, and stirring and evaporating at 70 ℃ to dryness to obtain composite powder;
the mass purity of the nano-crystalline tungsten trioxide is 99.98%, the average grain size is 150nm, and the specific surface area is 7g/cm3；
The carbon nano-particles are nearly spherical particles, the average particle size is 80nm, and the specific surface area is 70g/cm3The carbon content in the carbon nano particles is 99.8 percent, and the mass of the carbon nano particles is 10.5 percent of the mass of the nano-crystalline tungsten trioxide after crushing and dispersing;
the adding mass of the dispersing agent PEG is 0.2 percent of the total mass of the carbon nano-particles and the nano-crystal tungsten trioxide after crushing and dispersing;
step two, laying the composite powder obtained in the step one until the thickness of a material layer is 30mm, and then reacting for 2 hours in a hydrogen atmosphere at 640 ℃ to perform primary hydrogen reduction to obtain a mixture; the dew point of the hydrogen atmosphere is less than-40 ℃, the mixture consists of carbon nano-particles and superfine/nano tungsten dioxide, wherein the average particle size of the superfine/nano tungsten dioxide is 300 nm;
step three, paving the mixture obtained in the step two until the thickness of a material layer is 30mm, and then preserving heat for 1h under the conditions that the vacuum degree is 0.01Pa and the temperature is 1050 ℃ to carry out second-stage reduction to obtain nano tungsten powder; the average particle size of the nano tungsten powder is 100 nm.
The dispersant in this embodiment may be one or two or more of PEG, PVP, and PVA other than PEG.
The application of the nano tungsten powder of the present invention is described in detail in examples 6 to 8.
Example 6
The specific process of this embodiment is as follows: the nano tungsten powder prepared in the example 1 is sintered for 10min at 1400 ℃ and 40MPa by adopting a spark plasma method, namely an SPS method, and the ultra-fine crystal tungsten with the theoretical density of 95% is prepared.
Example 7
The specific process of this embodiment is as follows: the nano tungsten powder prepared in the embodiment 4 is pressed and molded under the pressure of 200MPa, and then is sintered for 2 hours at the temperature of 1500 ℃ under the hydrogen atmosphere, so that the fine crystal tungsten with the theoretical density of 97% is prepared.
Example 8
The specific process of this embodiment is as follows: the nano tungsten powder prepared in the example 1 and carbon nano particles accounting for 6.13% of the mass fraction of the nano tungsten powder are mixed and then are subjected to heat preservation for 3 hours at 1100 ℃ in a hydrogen atmosphere, so that the nano tungsten carbide powder is prepared.
The above description is only for the preferred embodiment of the present invention, and is not intended to limit the present invention in any way. Any simple modification, change and equivalent changes of the above embodiments according to the technical essence of the invention are still within the protection scope of the technical solution of the invention.
Claims (7)
1. A method for preparing nano tungsten powder by regulating nucleation and growth processes is characterized by comprising the following steps:
step one, crushing and dispersing nanocrystalline tungsten trioxide, ultrasonically dispersing the crushed and dispersed nanocrystalline tungsten trioxide and carbon nanoparticles in an ethanol solution with the aid of a dispersing agent, stirring at room temperature, and stirring and evaporating to dryness to obtain composite powder;
step two, laying the composite powder obtained in the step one, reacting for 1-4 h at 550-640 ℃ in a hydrogen atmosphere, and carrying out primary hydrogen reduction to obtain a mixture; the mixture consists of carbon nano-particles and superfine tungsten dioxide, wherein the average particle size of the superfine tungsten dioxide is 100-300 nm;
step three, laying the mixture obtained in the step two, and then preserving heat for 1-5 hours at 950-1050 ℃ for second-stage reduction to obtain nano tungsten powder; the average particle size of the nano tungsten powder is 20 nm-100 nm.
2. The method for preparing nano tungsten powder by regulating nucleation and growth processes according to claim 1, wherein the nano-crystalline tungsten trioxide in the step one is nano-crystalline yellow tungsten or nano-crystalline blue tungsten, the average grain size of the nano-crystalline tungsten trioxide is 40nm to 150nm, and the specific surface area is 7g/cm3~14g/cm3(ii) a In the step one, the average particle size of the carbon nano-particles is 5 nm-80 nm, and the specific surface area is 70g/cm3~500g/cm3The carbon content in the carbon nano particles is more than 99%, and the mass of the carbon nano particles is 9.2-10.5% of the mass of the nano-crystalline tungsten trioxide after crushing and dispersing.
3. The method for preparing nano tungsten powder by regulating nucleation and growth processes according to claim 1, wherein the crushing and dispersing mode in the step one is grinding or ball milling, or combination of ball milling and ultrasound, or combination of grinding and ultrasound, and the crushing and dispersing time is 0.5-5 h.
4. The method for preparing nano tungsten powder by regulating nucleation and growth processes according to claim 1, wherein the dispersant is one or more of PEG, PVP and PVA in the first step, and the adding mass of the dispersant is 0.2-1.2% of the total mass of the carbon nano particles and the nano-crystalline tungsten trioxide after crushing and dispersing.
5. The method for preparing the nano tungsten powder by regulating and controlling the nucleation and growth processes according to claim 1, wherein in the step one, the stirring time at room temperature is 0.5-4 h; the temperature for stirring and evaporating to dryness is 60-80 ℃.
6. The method for preparing the nano tungsten powder by regulating and controlling the nucleation and growth processes according to claim 1, wherein the thickness of a material layer after the composite powder is laid in the second step is 5 mm-30 mm, and the dew point of a hydrogen atmosphere is less than-40 ℃; in the third step, the thickness of the material layer after the mixture is laid is 5 mm-30 mm, and the atmosphere adopted by the second-stage reduction is vacuum or inert atmosphere.
7. Use of the nano tungsten powder prepared by the method according to any one of claims 1 to 6, wherein the nano tungsten powder is sintered to prepare a fine grain/ultra fine grain tungsten-based alloy, or the nano tungsten powder is carbonized to prepare an ultra fine tungsten carbide powder.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011413644.5A CN112222418B (en) | 2020-12-07 | 2020-12-07 | Method for preparing nano tungsten powder by regulating nucleation and growth processes and application |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011413644.5A CN112222418B (en) | 2020-12-07 | 2020-12-07 | Method for preparing nano tungsten powder by regulating nucleation and growth processes and application |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112222418A CN112222418A (en) | 2021-01-15 |
| CN112222418B true CN112222418B (en) | 2021-03-16 |
Family
ID=74124771
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011413644.5A Active CN112222418B (en) | 2020-12-07 | 2020-12-07 | Method for preparing nano tungsten powder by regulating nucleation and growth processes and application |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112222418B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115229199B (en) * | 2022-09-23 | 2022-12-27 | 西安稀有金属材料研究院有限公司 | Method for preparing high-dispersion high-porosity superfine molybdenum dioxide and molybdenum powder by induced nucleation |
| CN115229201B (en) * | 2022-09-23 | 2022-12-09 | 西安稀有金属材料研究院有限公司 | Preparation method of high-dispersion nano tungsten powder |
| CN116606072B (en) * | 2023-07-20 | 2023-10-27 | 内蒙古兴固科技有限公司 | Preparation method of ultrathin ultra-wide nano microcrystalline plate |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5236550A (en) * | 1975-09-18 | 1977-03-19 | Mitsubishi Metal Corp | Method to manufacture nickel base alloy powder |
| US4131450A (en) * | 1977-02-04 | 1978-12-26 | Mitsubishi Kinzoku Kabushiki Kaisha | Process for manufacturing cobalt-base reduced powder |
| CN1234489C (en) * | 2003-09-10 | 2006-01-04 | 厦门金鹭特种合金有限公司 | Preparation method of high performance nanometer sized and superfine tungsten powder |
| KR100769348B1 (en) * | 2006-03-17 | 2007-11-27 | 주식회사 나노테크 | Manufacturing method for ultra fine composite powder of tungsten carbide and cobalt |
| CN103100720A (en) * | 2013-02-28 | 2013-05-15 | 齐国超 | Preparation method for high-purity low-gas chromium powder |
| CN103862038A (en) * | 2014-03-14 | 2014-06-18 | 中南大学 | Extra-coarse hard alloy parcel powder and preparation method thereof |
| CN104874806B (en) * | 2014-12-22 | 2017-05-03 | 南京大学 | Preparation method for superfine low-oxygen-content spherical copper powder |
| CN108080649B (en) * | 2017-12-14 | 2021-08-03 | 钢研晟华科技股份有限公司 | Method for preparing superfine iron powder by low-temperature hydrocarbon duplex reduction |
| CN108500283B (en) * | 2018-04-23 | 2019-12-31 | 北京科技大学 | Method for preparing nano tungsten powder by low-cost two-stage reduction |
-
2020
- 2020-12-07 CN CN202011413644.5A patent/CN112222418B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN112222418A (en) | 2021-01-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN112222418B (en) | Method for preparing nano tungsten powder by regulating nucleation and growth processes and application | |
| CN112222419B (en) | Method for preparing nano molybdenum powder by regulating nucleation and growth processes and application | |
| CN106077695B (en) | A kind of preparation method of high-copper tungsten copper nano composite powder | |
| Dong et al. | The simultaneous improvements of strength and ductility in W–Y2O3 alloy obtained via an alkaline hydrothermal method and subsequent low temperature sintering | |
| Hu et al. | Microstructure refinement and mechanical properties improvement in the W-Y2O3 alloys via optimized freeze-drying | |
| CN111408714B (en) | Preparation method of graphene reinforced copper-based composite material with dual-scale structure and in-situ growth | |
| CN112222421B (en) | Preparation method and application of nano tungsten trioxide and nano tungsten powder | |
| JP4063151B2 (en) | Porous spherical nickel powder and method for producing the same | |
| Liu et al. | Eliminating bimodal structures of W-Y2O3 composite nanopowders synthesized by wet chemical method via controlling reaction conditions | |
| CN113106281B (en) | Preparation method of yttrium oxide doped tungsten-based nano composite powder and alloy thereof | |
| CN108788173B (en) | Hydrothermal preparation method of superfine yttrium oxide doped tungsten composite powder | |
| CN106216705A (en) | A kind of preparation method of 3D printing fine grained simple substance globular metallic powder | |
| CN112831733B (en) | Amorphous coated Y2O3Composite material and powder preparation method thereof | |
| Huang et al. | Uniformly dispersed Y2O3 nanoparticles in nanocrystalline copper matrix via multi-step ball milling and reduction process | |
| Wan et al. | Synthesis and characterization of W–Cu nanopowders by a wet-chemical method | |
| CN109848428A (en) | The preparation method and metal soft magnetic composite material of metal soft magnetic composite material | |
| Cheng et al. | Comparative study of the microstructure and phase evolution of FeCoCrNiAl high-entropy alloy-matrix WC nanocomposite powders prepared by mechanical alloying | |
| EP1151817A2 (en) | Method for preparing metal powder by thermal decomposition | |
| Wang et al. | Study on influencing factors and mechanism of high-quality tungsten carbide nanopowders synthesized via carbothermal reduction | |
| Songping et al. | Preparation of ultra fine copper–nickel bimetallic powders for conductive thick film | |
| CN111041318A (en) | Tungsten-copper alloy and preparation method thereof | |
| Biyik | Effect of Y2O3 addition and milling time on the synthesis of nanocrystalline Ag–ZnO composite powder via mechanical alloying | |
| CN109128143B (en) | Preparation method of nano tungsten-copper powder with core-shell structure | |
| CN115229202B (en) | Preparation method of molybdenum-copper nano composite powder | |
| Zhang et al. | Effects of various rare earth oxides on morphology and size of oxide dispersion strengthening (ODS)-W and ODS-Mo alloy powders |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |