CN1250485C - Method for preparing high density nano ceramic - Google Patents
Method for preparing high density nano ceramic Download PDFInfo
- Publication number
- CN1250485C CN1250485C CN 200410083676 CN200410083676A CN1250485C CN 1250485 C CN1250485 C CN 1250485C CN 200410083676 CN200410083676 CN 200410083676 CN 200410083676 A CN200410083676 A CN 200410083676A CN 1250485 C CN1250485 C CN 1250485C
- Authority
- CN
- China
- Prior art keywords
- sample
- pyrophyllite
- pressure
- graphite furnace
- nano
- 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
Landscapes
- Compositions Of Oxide Ceramics (AREA)
Abstract
The present invention discloses a making method for high density nanometer ceramics. The method comprises the following steps: step 1), nanometer powder is pressed into a sheet on a preforming machine through a steel mould under the pressure of 7MPas at a room temperature; step 2), after the isostatic cool pressing of the prepressed sample is carried out on a pressing machine with a six side top, the pressed sample is milled into powder, and then, the nanometer powder is pressed into a sheet on the preforming machine according to step 1); step 3), the pressed sample is put in a boron nitride pipe, the boron nitride pipe is put in a graphite furnace, the graphite furnace is put in a pyrophyllite block, the pyrophyllite block is used as a pressure transmitting medium, and the graphite furnace is used as a heating furnace; the pyrophyllite block with the graphite furnace is put in the pressing machine with a six side top, 5 to 7Gpa of pressure is applied to the pyrophyllite block, and after the pressure is reached, the pyrophyllite block is heated to 900 to 1100 DEG C; then, the heat preservation of the pyrophyllite block is carried out at a high temperature and under high pressure. The method provided by the present invention has the advantages of simple and rational technology, low cost, easy operation, low ceramic sintering temperature and short sintering time.
Description
Technical field
The present invention relates to a kind of preparation method who utilizes high pressure to obtain high density nano ceramic, mainly is to be applied to prepare the nano functional pottery.
Background technology
Function ceramics is the material system that a big class has physicalies such as electricity, magnetic, sound, heat, light, and its main application fields is the electronic devices and components of widespread use in information technology.Development along with mobile communication and satellite communication, especially in the last few years, an important development trend of function ceramics is exactly that device weight constantly alleviates, size is constantly dwindled, miniaturization, integrated, chip type, multiple stratification, multifunction become the main flow of development gradually, particularly entered since 21st century, based on the development of the microelectronics of semi-conductor, characteristic dimension will drop to below the 100nm.Function ceramics must be faced the challenge of nanotechnology, and this is the technical foundation that realizes miniaturization/microminiaturization.Therefore, function ceramics nanometer, nano ceramics, nano-device are the inexorable trends that the information pottery further develops, and are also just becoming a new focus of international research.The nano functional pottery not only has the undersized characteristics with nanostructure, and also has the performance of all special strangenesss, this for design new functional materials provide may, also for tempting prospect is provided in future of function ceramics.
Since nineteen forty-three, barium titanate was found, barium titanate ceramics material is owing to have higher dielectric constant, good ferroelectric, piezoelectricity, withstand voltage and insulating property, become a kind of very important functional material, in multi-layer capacitor, ultrasonic wave and pressure transmitter, electroregulator, optoelectronic device and portable machine and (computer) dynamic RAM, be widely used.
But in the densification process of nano ceramics, should make ceramic densifying, keep original nano-scale again, technology is very difficult, and reason is intensive rubbing effect between the low apparent density of nano powder, low turnover rate, very strong gas and the chemisorption of mixture, relative high surface-area and particle.These reasons are reunited nano powder easily, if do not smash coacervate before sintering, can cause growing up and the discontinuous growth of crystal grain of coacervate so when the sintering nano powder, so that lose the advantage that nano-sized grains had.Suppress grain growing if add additive, doing like this is cost to reduce performance machinery or physics often.Therefore in the sintering of nano ceramics, must take all necessary measure and control growing up of crystal grain.The sintering method of conventional pottery is difficult to obtain highdensity nano ceramics.
Summary of the invention
The objective of the invention is to overcome the shortcoming that conventional ceramic sintering technology is difficult to obtain high density nano ceramic, utilize ultra-high voltage, a kind of preparation method who prepares high density nano ceramic is provided the influence of nano powder agglomerating.The present invention adopts the method for coacervate in the nano powder of crushing before sintering to reach the purpose of preparation nano ceramics.Adopt the nano ceramics grain size distribution of this method preparation even, crystal grain is in nano-scale range.
The object of the present invention is achieved like this:
Ultra-high voltage is to the influence of nano powder agglomerating, and on the one hand, high pressure energy increases fine and close motivating force, and pressure is big more, and the motivating force increase is big more, so can obtain fine and close pottery; On the other hand, high pressure energy reduces diffusivity, so that reduce grain growing speed, suppresses grain growing, so can obtain nano ceramics.
The present invention utilizes superhighpressure technology, and utilization three-step approach sintering prepares high density nano ceramic.Concrete purpose is achieved in that
1) at room temperature, with nano powder unidirectional pressurization tablet forming of pressure with 7MPa on tabletting machine, the dwell time is 3～5 minutes with steel die;
2) sample that will press is in advance wrapped with aluminium foil, that packs into and handled beats in the foraminous pyrophyllite in lumps, the sample two ends are blocked with the pyrophyllite post, on six-plane piercer, use pressure isostatic cool pressing then greater than 500Mpa, pyrophyllite is made transmission medium, dwell time is 5～10 minutes, afterwards the sample that presses is worn into powder, again according to step 1) with nano powder tablet forming on tabletting machine.This step is the key that obtains nano ceramics, and its purpose is the coacervate of eliminating in the nano powder, prevents in high pressure-temperature sintering subsequently the growing up of coacervate.Its required pressure is the required minimal pressure of crushing coacervate, generally should be greater than 500MPa;
3) sample that presses is wrapped with silver foil, to prevent pollution; Put into boron nitride tube then, again boron nitride tube is put into graphite furnace, the boron nitride tube two ends are blocked with the boron nitride post, afterwards graphite furnace is packed into and beat in the foraminous pyrophyllite in lumps, the graphite furnace two ends are put graphite flake and molybdenum sheet successively, last whole pyrophyllite hole is blocked up with the steel loop that has aluminium foil to wrap (filling up with the pyrophyllite fragment in the ring), pyrophyllite is made transmission medium, graphite furnace is made process furnace and is used, the pyrophyllite that installs is put into six-plane piercer and is pressurized to 5～7GPa, reach pressure and begin heating afterwards, being heated to temperature is 900～1100 ℃, 300～360 ℃/minute of temperature rise rates are incubated 5～15 minutes then under this high pressure-temperature condition.After sample was burned, sample was taken out in the cooling back release of quenching, and peels the silver foil on the sample then off, can obtain nano ceramics.(1GP,a=1 ten thousand normal atmosphere)
Method technology provided by the invention is simple, reasonable, and cost is low, easy handling.Ceramic sintering temperature is low, and sintering time is short.The nano ceramics grain size distribution that obtains with this invention is even, and crystal grain does not have growing up of coacervate in nano-scale range; The density of pottery is higher simultaneously, near theoretical density.
Description of drawings
Below in conjunction with drawings and Examples the present invention is described further.
Fig. 1 is the device of isostatic cool pressing specimen holder of the present invention.
Fig. 2 is the device of High Temperature High Pressure specimen holder of the present invention.
Fig. 3 is 10nm BaTiO of the present invention
3Powder is 100,000 times of scanning electron microscope (SEM) photo behind the three-step approach sintering.
Fig. 4 is 10nm BaTiO of the present invention
3Powder is 200,000 times of scanning electron microscope (SEM) photo behind the three-step approach sintering.
Embodiment:
Embodiment: three-step approach sintering high-density BaTiO
3Nano ceramics.
The preparation method of this embodiment may further comprise the steps:
1) at room temperature, with the BaTiO of 10nm
3Nano powder uses the steel die of Ф 6mm to use the unidirectional pressurization of pressure of 7MPa on tabletting machine, and the dwell time is 5 minutes;
2) as shown in Figure 1, the sample 3 usefulness aluminium foils that press are in advance wrapped, the volume of handling that is equipped with Ф 6.5mm hole of packing into is in 28 * 28 * 28 pyrophyllite in lumps 1, the sample two ends are blocked with pyrophyllite post 2, isostatic cool pressing on six-plane piercer then, the about 3GPa of pressure, pyrophyllite is made transmission medium, and the dwell time is 10 minutes; Afterwards the sample 3 that presses is worn into powder, again according to step 1) with nano powder tablet forming on tabletting machine; The sample size that presses is that diameter is 6mm, and thickness is 2mm;
3) as shown in Figure 2, with the BaTiO that presses
3Sample 9 usefulness silver foil are wrapped, to prevent pollution; Put into boron nitride tube 11 then, again boron nitride tube is put into graphite furnace 4, the boron nitride tube two ends are blocked with boron nitride post 10, afterwards graphite furnace is packed into and beat in the foraminous pyrophyllite in lumps 8, the graphite furnace two ends are put graphite flake 5 and molybdenum sheet 6 successively, last whole pyrophyllite hole is blocked up with the steel loop 7 that has aluminium foil to wrap (filling up with the pyrophyllite fragment in the ring), pyrophyllite is made transmission medium, graphite furnace is made process furnace and is used, the pyrophyllite that installs is put into six-plane piercer and is pressurized to 6GPa, reach pressure and begin heating afterwards, being heated to temperature is 1000 ℃, 330 ℃/minute of temperature rise rates are incubated 5 minutes then under the high pressure-temperature condition.After sample was burned, the cooling back release of quenching promptly obtained BaTiO
3The nano ceramics sample.Peel the silver foil on the sample off, sample preparation, and make the electron-microscope scanning of 100,000 times and 200,000 times, and shown in Fig. 3,4, the crystal grain of sample is evenly distributed, and grain-size is 50nm.Through measuring, the relative density of sample is 98%.
Claims (1)
1, a kind of preparation method of high density nano ceramic is characterized in that, comprises the steps:
1) at room temperature, with nano powder unidirectional pressurization tablet forming of pressure with 7MPa on tabletting machine, the dwell time is 3～5 minutes with steel die;
2) sample that will press is in advance wrapped with aluminium foil, that packs into and handled beats in the foraminous pyrophyllite in lumps, the sample two ends are blocked with the pyrophyllite post, on six-plane piercer, use pressure isostatic cool pressing then greater than 500MPa, pyrophyllite is made transmission medium, dwell time is 5～10 minutes, afterwards the sample that presses is worn into powder, again according to step 1) with nano powder tablet forming on tabletting machine;
3) sample that presses is wrapped with silver foil, to prevent pollution; Put into boron nitride tube then, again boron nitride tube is put into graphite furnace, afterwards graphite furnace is packed in the pyrophyllite in lumps, pyrophyllite is made transmission medium, and graphite furnace is made process furnace usefulness, and the pyrophyllite that installs is put into six-plane piercer and is pressurized to 5～7GPa, begin heating after reaching pressure, be heated to 900～1100 ℃, 300～360 ℃/minute of temperature rise rates are incubated 5～15 minutes then under this high pressure-temperature condition; After sample is burned, quenches and lower the temperature the back release and take out sample.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200410083676 CN1250485C (en) | 2004-10-15 | 2004-10-15 | Method for preparing high density nano ceramic |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200410083676 CN1250485C (en) | 2004-10-15 | 2004-10-15 | Method for preparing high density nano ceramic |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1603282A CN1603282A (en) | 2005-04-06 |
| CN1250485C true CN1250485C (en) | 2006-04-12 |
Family
ID=34667009
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200410083676 Expired - Fee Related CN1250485C (en) | 2004-10-15 | 2004-10-15 | Method for preparing high density nano ceramic |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1250485C (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106116567B (en) * | 2016-06-22 | 2018-11-02 | 刘和来 | The preparation method of high density nano barium titanate titanate ceramics |
| CN106083035B (en) * | 2016-06-22 | 2018-11-02 | 刘和来 | A kind of piezoelectric acceleration transducer standby using nano barium phthalate ceramic system |
| CN106092687B (en) * | 2016-06-24 | 2019-03-12 | 中国科学院地球化学研究所 | A kind of preparation method of galena electrode |
| CN105973796B (en) * | 2016-06-24 | 2019-03-08 | 中国科学院地球化学研究所 | A kind of preparation method of chalcopyrite electrode |
| CN107640787B (en) * | 2017-09-04 | 2019-04-02 | 中国科学院地球化学研究所 | A method of preparing mangandolomite at high temperature under high pressure |
-
2004
- 2004-10-15 CN CN 200410083676 patent/CN1250485C/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| CN1603282A (en) | 2005-04-06 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US6048511A (en) | Method for forming high density boron nitride and high density agglomerated boron nitride particles | |
| CN102703742B (en) | Metal-based composite material with substrate of nano laminated structure and preparation method thereof | |
| CN109437920B (en) | Nanometer/submicron structure wBN superhard material, wBN-cBN superhard composite material, preparation method and cutter | |
| CN106363185B (en) | The method for preparing powder metallurgy of nanometer phase/composite metal powder and its block materials | |
| CN1250485C (en) | Method for preparing high density nano ceramic | |
| CN112225186B (en) | Preparation method of spherical boron nitride | |
| EP0939066B1 (en) | Method for forming high density boron nitride and high density agglomerated boron nitride particles | |
| CA3185734A1 (en) | Producing catalyst-free pdc cutters | |
| CN110424053B (en) | Method for preparing nano-structure block material | |
| KR102529034B1 (en) | 3-dimensional graphene-metal composite and manufacturing method of the same | |
| CA3162473A1 (en) | Method for producing uranium carbide/mwcnt disc which is isol target material, and uranium carbide/mwcnt disc produced by same | |
| CN106083035B (en) | A kind of piezoelectric acceleration transducer standby using nano barium phthalate ceramic system | |
| CN1817434A (en) | Method for sintering polycrystal cubic boron nitride by plasma discharge | |
| CN1647877A (en) | Method for preparing nano grade tungsten powder | |
| CN114717441B (en) | Method for preparing diamond/copper composite material with low density and high thermal conductivity at low cost | |
| CN111497367A (en) | High-heat-conductivity body and preparation method thereof | |
| Ponnuchamy et al. | Preparation of nanocrystalline nickel oxide from nickel hydroxide using spark plasma sintering and inverse Hall-Petch related densification | |
| Liu et al. | Strengthening of alumina ceramics under cold compression | |
| Zhang et al. | Preparation of bulk nano-aluminum materials from nanopowder using explosive consolidation | |
| US20090243164A1 (en) | Preparation of a dense, polycrystalline ceramic structure | |
| US9120245B1 (en) | Methods for fabrication of parts from bulk low-cost interface-defined nanolaminated materials | |
| CN113480313A (en) | MXene toughened ultrahigh-temperature ceramic composite material and preparation method thereof | |
| CN112794314A (en) | Preparation method of high-density graphene heat-conducting film regulated and controlled by groups and obtained product | |
| CN106116567B (en) | The preparation method of high density nano barium titanate titanate ceramics | |
| CN112875707B (en) | High-purity low-oxygen silicon powder and preparation method thereof |
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 | ||
| C19 | Lapse of patent right due to non-payment of the annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |