CN114315372A - Preparation process of high-strength h-BN ceramic - Google Patents
Preparation process of high-strength h-BN ceramic Download PDFInfo
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- CN114315372A CN114315372A CN202011054362.0A CN202011054362A CN114315372A CN 114315372 A CN114315372 A CN 114315372A CN 202011054362 A CN202011054362 A CN 202011054362A CN 114315372 A CN114315372 A CN 114315372A
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- 239000000919 ceramic Substances 0.000 title claims abstract description 31
- 238000002360 preparation method Methods 0.000 title claims abstract description 23
- 238000000034 method Methods 0.000 claims abstract description 14
- 229910052582 BN Inorganic materials 0.000 claims abstract description 11
- PZNSFCLAULLKQX-UHFFFAOYSA-N Boron nitride Chemical compound N#B PZNSFCLAULLKQX-UHFFFAOYSA-N 0.000 claims abstract description 11
- 238000010438 heat treatment Methods 0.000 claims description 27
- 239000002994 raw material Substances 0.000 claims description 25
- 239000000843 powder Substances 0.000 claims description 23
- 238000002156 mixing Methods 0.000 claims description 18
- 238000001816 cooling Methods 0.000 claims description 15
- 229910010293 ceramic material Inorganic materials 0.000 claims description 11
- 238000000498 ball milling Methods 0.000 claims description 10
- 239000011812 mixed powder Substances 0.000 claims description 9
- 229910052580 B4C Inorganic materials 0.000 claims description 8
- 229910052581 Si3N4 Inorganic materials 0.000 claims description 8
- 229910026551 ZrC Inorganic materials 0.000 claims description 8
- OTCHGXYCWNXDOA-UHFFFAOYSA-N [C].[Zr] Chemical compound [C].[Zr] OTCHGXYCWNXDOA-UHFFFAOYSA-N 0.000 claims description 8
- INAHAJYZKVIDIZ-UHFFFAOYSA-N boron carbide Chemical compound B12B3B4C32B41 INAHAJYZKVIDIZ-UHFFFAOYSA-N 0.000 claims description 8
- 239000002245 particle Substances 0.000 claims description 8
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 claims description 8
- 238000001035 drying Methods 0.000 claims description 6
- 238000007580 dry-mixing Methods 0.000 claims description 5
- VLKZOEOYAKHREP-UHFFFAOYSA-N n-Hexane Chemical compound CCCCCC VLKZOEOYAKHREP-UHFFFAOYSA-N 0.000 claims description 4
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 claims description 3
- 229910010271 silicon carbide Inorganic materials 0.000 claims description 3
- 238000003746 solid phase reaction Methods 0.000 abstract description 6
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical group [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 abstract description 5
- 239000000463 material Substances 0.000 abstract description 5
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 abstract description 4
- 229910002804 graphite Inorganic materials 0.000 abstract description 4
- 239000010439 graphite Substances 0.000 abstract description 4
- 238000009776 industrial production Methods 0.000 abstract description 3
- 230000005540 biological transmission Effects 0.000 abstract description 2
- 238000002474 experimental method Methods 0.000 abstract description 2
- 239000012212 insulator Substances 0.000 abstract description 2
- 238000002844 melting Methods 0.000 abstract description 2
- 230000008018 melting Effects 0.000 abstract description 2
- 229910052751 metal Inorganic materials 0.000 abstract description 2
- 239000002184 metal Substances 0.000 abstract description 2
- 125000004433 nitrogen atom Chemical group N* 0.000 abstract description 2
- 230000035939 shock Effects 0.000 abstract description 2
- 239000000126 substance Substances 0.000 abstract description 2
- 229910052593 corundum Inorganic materials 0.000 description 6
- 239000010431 corundum Substances 0.000 description 6
- 238000001878 scanning electron micrograph Methods 0.000 description 4
- 238000005245 sintering Methods 0.000 description 4
- 238000001354 calcination Methods 0.000 description 3
- 230000002194 synthesizing effect Effects 0.000 description 3
- 238000004321 preservation Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 229910052796 boron Inorganic materials 0.000 description 1
- 238000009694 cold isostatic pressing Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- JDSHMPZPIAZGSV-UHFFFAOYSA-N melamine powder Natural products NC1=NC(N)=NC(N)=N1 JDSHMPZPIAZGSV-UHFFFAOYSA-N 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 239000007790 solid phase Substances 0.000 description 1
- ZVWKZXLXHLZXLS-UHFFFAOYSA-N zirconium nitride Chemical compound [Zr]#N ZVWKZXLXHLZXLS-UHFFFAOYSA-N 0.000 description 1
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Abstract
The invention relates to a preparation process of high-strength h-BN ceramic, belonging to the technical field of high-temperature structure function integrated ceramic. The material can be applied to radar transmission windows, antenna housing materials, high-temperature metal melting crucibles, thermocouple protection tubes, radiating fins, structural materials of nuclear reactors and the like. Hexagonal boron nitride (h-BN) is formed by covalently bonding boron atoms and nitrogen atoms, has a layered structure similar to graphite, and is called white graphite. BN is a good insulator, has the advantages of small thermal expansion coefficient and high shock resistance, and also has high chemical stability and excellent thermal stability. The invention relates to a high-strength h-BN ceramic prepared by high-temperature solid-phase reaction. The preparation method is simple, the requirement on the preparation environment is low, and large-scale industrial production can be realized. The performance of the BN ceramic prepared by the experiment is superior to that of the BN ceramic prepared by the traditional process, the strict requirements of the high and new technical field can be met, and the BN ceramic has wider application.
Description
Technical Field
The invention relates to a preparation process of high-strength h-BN ceramic, belongs to the technical field of high-temperature structural function integrated ceramic, and is applicable to radar transmission windows, antenna housing materials, high-temperature metal melting crucibles, thermocouple protection tubes, radiating fins, structural materials of nuclear reactors and the like.
Background
Hexagonal boron nitride (h-BN) is formed by covalently bonding boron atoms and nitrogen atoms, has a layered structure similar to graphite, and is called white graphite. BN is a good insulator, has the advantages of small thermal expansion coefficient and high shock resistance, and also has high chemical stability and excellent thermal stability.
The preparation method of the h-BN ceramic mainly adopts h-BN powder to form the h-BN ceramic through high-temperature sintering. Because h-BN is a compound with strong covalent bonds, the solid phase diffusion coefficient is low, and the unique lamellar structure is easy to form a card house type structure in the sintering process, the sintering performance is poor, and the ceramic with high density is difficult to obtain.
The high-strength h-BN ceramic is prepared through high-temperature solid-phase reaction. The preparation method is simple, the requirement on the preparation environment is low, and large-scale industrial production can be realized. The performance of the BN ceramic prepared by the experiment is superior to that of the BN ceramic prepared by the traditional process, the strict requirements of the high and new technical field can be met, and the BN ceramic has wider application.
Disclosure of Invention
The invention aims to solve the problems that the h-BN ceramic material has poor sintering performance and is difficult to obtain h-BN ceramic with high density and high strength. The invention provides a high-efficiency and simple method for preparing high-strength BN ceramic through high-temperature solid-phase reaction. The method has simple requirements on raw materials, low risk and large-scale preparation. The method takes zirconium carbide, boron carbide, silicon nitride and boron nitride as raw materials, and generates nano h-BN grains through high-temperature solid-phase reaction to prepare the high-strength boron carbonitride ceramic material.
The technical scheme adopted by the invention is as follows: a preparation process of high-strength h-BN ceramic comprises the following steps:
1) uniformly mixing 10-70% of zirconium carbide powder, 0-50% of boron carbide powder, 0-60% of silicon nitride powder and 0-50% of boron nitride powder according to mass fraction to obtain a raw material;
2) placing the raw materials in a ball mill for ball milling, and drying after the raw materials are uniformly mixed to obtain mixed powder with the particle size of less than 20 microns, wherein the mixing mode can be divided into dry mixing and wet mixing;
3) placing the uniformly mixed powder in a mold and a heating furnace with a vacuum degree of about 1.0 × 101Pa, heating to 1300-2500 ℃ at the speed of 3-15 ℃/min, pressurizing to 20-50MPa, keeping the temperature and pressure for 1-6h, cooling at the cooling speed of 5 ℃/min to 1000-1500 ℃, and releasing the pressure;
4) taking out the mould, and taking out the sintered sample to obtain the ceramic material containing the superfine silicon carbide;
furthermore, the particle diameters of the zirconium carbide powder, the boron carbide powder, the silicon nitride powder and the boron nitride powder are all less than 20 micrometers;
further, the ball milling mode in the raw material mixing process in the step 2) is divided into a dry mixing mode and a wet mixing mode, wherein the ball milling medium for wet mixing is n-hexane;
further, the temperature rise process in the step 3) is divided into three steps, wherein in the first step, the temperature is raised from room temperature to 1200-1400 ℃ at the speed of 10-15 ℃/min, in the second step, the temperature is raised to 1500-1700 ℃ at the speed of 6-10 ℃/min, and in the third step, the temperature is raised to 1800-2500 ℃ at the speed of 3-8 ℃/min;
further, the temperature in the step 3) is increased to 1400-2500 ℃, and the heat preservation time is 1-6 h;
further, the pressurizing pressure in the step 3) is 20-50MPa, and the temperature and pressure are kept;
further, the temperature in the step 4) is increased to 1400-2500 ℃, and the heat preservation time is 1-6 h;
further, the temperature reduction and cooling in the step 4) are 5 ℃/min. Cooling to 1000-;
the invention has the beneficial effects that: zirconium carbide, boron carbide and silicon nitride are used as raw materials, and the high-strength h-BN ceramic with smaller grain size is generated through cold pressing and high-temperature solid phase reaction. Compared with the existing h-BN ceramic, the h-BN ceramic prepared by the solid-phase reaction has smaller grain size, higher density and higher strength. The preparation process provided by the invention is simple, the raw material cost is reduced, the safety is high, the control is easy, and the preparation method can be used for industrial production.
Drawings
FIG. 1: a schematic diagram of the h-BN crystal structure;
FIG. 2: example one SEM image of an h-BN ceramic;
FIG. 3: example one SEM image of an h-BN ceramic;
FIG. 4: SEM image of example II h-BN ceramic;
FIG. 5: SEM image of example II h-BN ceramic;
FIG. 6: example one h-BN ceramic data.
Detailed Description
The method for preparing the h-BN ceramic according to the invention is described in detail below with reference to the examples.
Example one
A preparation method for synthesizing a high-strength h-BN ceramic material comprises the following steps:
1) uniformly mixing 8.5g of zirconium carbide, 5.6g of boron carbide, 8.5g of silicon nitride and 41g of boron nitride powder according to volume fraction to obtain a raw material;
2) putting the raw materials into a ball mill, adding corundum balls according to the mass ratio of 1:3 of the raw materials to the corundum balls, and drying after carrying out wet ball milling for 2 hours to obtain mixed powder with the particle size of less than 20 microns;
3) putting the raw materials into a mould and placing the mould into a heating furnace, wherein the calcination system is as follows: heating from room temperature to 500 ℃ at a heating rate of 10 ℃/min; then heating to 1400 ℃ at the heating rate of 7 ℃/min; then heating to 2000 ℃ at the heating rate of 5 ℃/min; pressurizing at 30MPa, and keeping the temperature and pressure for 60 min; cooling along with the furnace; thus obtaining the h-BN ceramic material.
Example two
A preparation method for synthesizing h-BN ceramic material comprises the following steps:
1) according to the mass ratio, the mass ratio of zirconium nitride, boron powder and boron nitride is 3: 2: 1, uniformly mixing the powder to obtain a raw material;
2) putting the raw materials into a ball mill, adding corundum balls according to the mass ratio of 1:3 of the raw materials to the corundum balls, performing wet ball milling for 2.5 hours, and drying to obtain mixed powder with the particle size of less than 20 microns;
3) placing the sample into a mold, placing the mold into a vacuum heating furnace, and calcining according to the following steps: heating from room temperature to 500 ℃ at a heating rate of 10 ℃/min; then heating to 1400 ℃ at the heating rate of 7 ℃/min; then heating to 1900 ℃ at the heating rate of 5 ℃/min; keeping the temperature and the pressure for 30min under the pressure of 30 MPa; cooling along with the furnace; thus obtaining the h-BN ceramic material.
EXAMPLE III
A preparation method for synthesizing a high-strength h-BN ceramic material comprises the following steps:
1) uniformly mixing boron powder and melamine powder according to the mass ratio of 3:2 to obtain a raw material;
2) putting the raw materials into a ball mill, adding corundum balls according to the mass ratio of 1:3 of the raw materials to the corundum balls, performing wet ball milling for 2.5 hours, and drying to obtain mixed powder with the particle size of less than 20 microns;
3) placing the sample into a rubber mold, forming under 50MPa cold isostatic pressing, and demolding to obtain a blank;
4) placing the blank in a vacuum heating furnace, wherein the calcination system is as follows: heating from room temperature to 500 ℃ at a heating rate of 10 ℃/min; then heating to 1400 ℃ at the heating rate of 7 ℃/min; then heating to 1800 ℃ at the heating rate of 5 ℃/min; preserving the temperature for 180 min; cooling along with the furnace; thus obtaining the h-BN-containing ceramic material.
In summary, the invention discloses a method for preparing high-strength h-BN ceramic, which comprises the following steps: 1) uniformly mixing 10-70% of zirconium carbide powder, 0-50% of boron carbide powder, 0-60% of silicon nitride powder and 0-50% of boron nitride powder according to mass fraction to obtain a raw material; 2) Placing the raw materials in a ball mill for ball milling, and drying after the raw materials are uniformly mixed to obtain mixed powder with the particle size of less than 20 microns, wherein the mixing mode can be divided into dry mixing and wet mixing; 3) placing the uniformly mixed powder in a mold and a heating furnace with a vacuum degree of about 1.0 × 101Pa, heating to 1300-2500 ℃ at the speed of 3-15 ℃/min, pressurizing to 20-50MPa, keeping the temperature and pressure for 1-6h, cooling at the cooling speed of 5 ℃/min, cooling to 1000-1500 ℃ and releasing the pressure. 4) And taking out the mold, and taking out the sintered sample to obtain the ceramic material containing the superfine silicon carbide. The preparation method is simple and can be used for large-scale preparation. Although the preferred embodiments of the present invention have been described, the present invention is not limited to the above-mentioned embodiments, which are only illustrative and not restrictive, and those skilled in the art can make many modifications without departing from the spirit and scope of the present invention as claimed in the appended claims.
Claims (7)
1. A preparation process of high-strength boron nitride ceramic is characterized by comprising the following experimental steps: 1) uniformly mixing 10-70% of zirconium carbide powder, 0-50% of boron carbide powder, 0-60% of silicon nitride powder and 0-50% of boron nitride powder according to mass fraction to obtain a raw material; 2) Placing the raw materials in a ball mill for ball milling, and drying after the raw materials are uniformly mixed to obtain mixed powder with the particle size of less than 20 microns, wherein the mixing mode can be divided into dry mixing and wet mixing; 3) placing the uniformly mixed powder in a mold and a heating furnace with a vacuum degree of about 1.0 × 101Pa, heating to 1300 ℃ and 2500 ℃ at the speed of 3-15 ℃/min, pressurizing to 20-50MPa, keeping the temperature and pressure for 1-6h, cooling at the cooling speed of 5 ℃/min, cooling to 1000 ℃ and 1500 ℃, and then releasing the pressure, 4) taking out the mold, and taking out the sintered sample to obtain the ceramic material containing the superfine silicon carbide.
2. The method according to claim 1, wherein the zirconium carbide powder, the boron carbide powder, the silicon nitride powder and the boron nitride powder of step 1) each have a particle size of less than 20 μm.
3. The preparation method of claim 1, wherein the ball milling manner in the mixing process of the raw materials in the step 2) is divided into a dry mixing manner and a wet mixing manner, wherein the ball milling medium for wet mixing is n-hexane.
4. The preparation method according to claim 1, wherein the temperature rise process in step 3) is divided into three steps, the temperature rise from room temperature to 1200-1400 ℃ at a rate of 10-15 ℃/min in the first step, the temperature rise from 6-10 ℃/min to 1500-1700 ℃ in the second step, and the temperature rise from 3-8 ℃/min to 1800-2500 ℃ in the third step.
5. The preparation method according to claim 1, wherein the temperature in the step 3) is raised to 1400-2500 ℃ and the holding time is 1-6 h.
6. The method according to claim 1, wherein the pressurizing pressure in step 3) is 20 to 50MPa, and the temperature and pressure are maintained.
7. The preparation method according to claim 1, wherein the temperature reduction and cooling in step 4) is 5 ℃/min,
cooling to 1000-1500 ℃, and then releasing pressure.
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Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4885264A (en) * | 1988-07-21 | 1989-12-05 | Elektroschmelzwerk Kempten Gmbh | Pressure-sintered polycpystalline mixed materials with a base of hexagonal boron nitride, oxides and carbides |
| JPH0912371A (en) * | 1995-06-29 | 1997-01-14 | Nkk Corp | Boron nitride-containing material and its production |
| CN1161947A (en) * | 1997-02-03 | 1997-10-15 | 汪宁 | Composite porcelain containing hexagonal boron nitride and preparation method thereof |
| CN101318636A (en) * | 2008-05-12 | 2008-12-10 | 中国科学院上海硅酸盐研究所 | Method for preparing hexagonal boron nitride containing composite material with nitridation in situ |
| CN105198443A (en) * | 2015-10-21 | 2015-12-30 | 哈尔滨工业大学 | Transition phase assisted low-temperature sintering method of boron nitride multi-phase ceramic |
| CN105399426A (en) * | 2015-11-16 | 2016-03-16 | 长兴鑫宇耐火材料有限公司 | Preparation method of boron nitride ceramic |
| CN105753485A (en) * | 2015-12-11 | 2016-07-13 | 天津城建大学 | Boron nitride composite ceramic material and pressureless sintering process thereof |
| CN109485421A (en) * | 2018-12-25 | 2019-03-19 | 清华大学深圳研究生院 | Structural ceramics and preparation method thereof based on carbonitride nanometer two-dimensional material toughening |
-
2020
- 2020-09-30 CN CN202011054362.0A patent/CN114315372A/en active Pending
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4885264A (en) * | 1988-07-21 | 1989-12-05 | Elektroschmelzwerk Kempten Gmbh | Pressure-sintered polycpystalline mixed materials with a base of hexagonal boron nitride, oxides and carbides |
| JPH0912371A (en) * | 1995-06-29 | 1997-01-14 | Nkk Corp | Boron nitride-containing material and its production |
| CN1161947A (en) * | 1997-02-03 | 1997-10-15 | 汪宁 | Composite porcelain containing hexagonal boron nitride and preparation method thereof |
| CN101318636A (en) * | 2008-05-12 | 2008-12-10 | 中国科学院上海硅酸盐研究所 | Method for preparing hexagonal boron nitride containing composite material with nitridation in situ |
| CN105198443A (en) * | 2015-10-21 | 2015-12-30 | 哈尔滨工业大学 | Transition phase assisted low-temperature sintering method of boron nitride multi-phase ceramic |
| CN105399426A (en) * | 2015-11-16 | 2016-03-16 | 长兴鑫宇耐火材料有限公司 | Preparation method of boron nitride ceramic |
| CN105753485A (en) * | 2015-12-11 | 2016-07-13 | 天津城建大学 | Boron nitride composite ceramic material and pressureless sintering process thereof |
| CN109485421A (en) * | 2018-12-25 | 2019-03-19 | 清华大学深圳研究生院 | Structural ceramics and preparation method thereof based on carbonitride nanometer two-dimensional material toughening |
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