CN1057515C - Method for deoxidisation and reinforcement of solid organic procursor of silicon nitride material - Google Patents
Method for deoxidisation and reinforcement of solid organic procursor of silicon nitride material Download PDFInfo
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- CN1057515C CN1057515C CN97119087A CN97119087A CN1057515C CN 1057515 C CN1057515 C CN 1057515C CN 97119087 A CN97119087 A CN 97119087A CN 97119087 A CN97119087 A CN 97119087A CN 1057515 C CN1057515 C CN 1057515C
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- silicon nitride
- carbon
- nitride powder
- silicon
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- 229910052581 Si3N4 Inorganic materials 0.000 title claims abstract description 39
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 title claims abstract description 39
- 238000000034 method Methods 0.000 title claims abstract description 17
- 239000000463 material Substances 0.000 title claims abstract description 10
- 230000002787 reinforcement Effects 0.000 title abstract 3
- 239000007787 solid Substances 0.000 title description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 33
- 239000000843 powder Substances 0.000 claims abstract description 31
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 30
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 16
- 239000001301 oxygen Substances 0.000 claims abstract description 16
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 16
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims abstract description 14
- 239000012071 phase Substances 0.000 claims abstract description 14
- 238000005245 sintering Methods 0.000 claims abstract description 14
- 239000002245 particle Substances 0.000 claims abstract description 12
- 239000002243 precursor Substances 0.000 claims abstract description 11
- 239000007790 solid phase Substances 0.000 claims abstract description 10
- 229910010271 silicon carbide Inorganic materials 0.000 claims abstract description 8
- 235000012239 silicon dioxide Nutrition 0.000 claims abstract description 8
- 229910010293 ceramic material Inorganic materials 0.000 claims abstract description 7
- 229920001187 thermosetting polymer Polymers 0.000 claims abstract description 6
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 claims abstract description 5
- 229910002091 carbon monoxide Inorganic materials 0.000 claims abstract description 5
- 239000000377 silicon dioxide Substances 0.000 claims abstract description 5
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 16
- KXGFMDJXCMQABM-UHFFFAOYSA-N 2-methoxy-6-methylphenol Chemical compound [CH]OC1=CC=CC([CH])=C1O KXGFMDJXCMQABM-UHFFFAOYSA-N 0.000 claims description 13
- 239000005011 phenolic resin Substances 0.000 claims description 13
- 229920001568 phenolic resin Polymers 0.000 claims description 13
- VKYKSIONXSXAKP-UHFFFAOYSA-N hexamethylenetetramine Chemical compound C1N(C2)CN3CN1CN2C3 VKYKSIONXSXAKP-UHFFFAOYSA-N 0.000 claims description 12
- 229920001169 thermoplastic Polymers 0.000 claims description 11
- 239000004416 thermosoftening plastic Substances 0.000 claims description 11
- 238000000197 pyrolysis Methods 0.000 claims description 10
- 238000000498 ball milling Methods 0.000 claims description 7
- 238000007731 hot pressing Methods 0.000 claims description 7
- 229910052757 nitrogen Inorganic materials 0.000 claims description 7
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 claims description 7
- 239000011248 coating agent Substances 0.000 claims description 6
- 238000000576 coating method Methods 0.000 claims description 6
- 238000001035 drying Methods 0.000 claims description 6
- 235000010299 hexamethylene tetramine Nutrition 0.000 claims description 6
- 239000004312 hexamethylene tetramine Substances 0.000 claims description 6
- SIWVEOZUMHYXCS-UHFFFAOYSA-N oxo(oxoyttriooxy)yttrium Chemical compound O=[Y]O[Y]=O SIWVEOZUMHYXCS-UHFFFAOYSA-N 0.000 claims description 6
- 238000010438 heat treatment Methods 0.000 claims description 5
- 239000000203 mixture Substances 0.000 claims description 5
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 4
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims description 4
- 238000001816 cooling Methods 0.000 claims description 4
- 239000011363 dried mixture Substances 0.000 claims description 4
- 229910002804 graphite Inorganic materials 0.000 claims description 3
- 239000010439 graphite Substances 0.000 claims description 3
- 238000011065 in-situ storage Methods 0.000 claims description 3
- 239000010453 quartz Substances 0.000 claims description 3
- 238000002156 mixing Methods 0.000 claims description 2
- 239000004531 microgranule Substances 0.000 claims 2
- 239000011259 mixed solution Substances 0.000 claims 1
- 229910052814 silicon oxide Inorganic materials 0.000 claims 1
- 239000011247 coating layer Substances 0.000 abstract description 5
- 239000007789 gas Substances 0.000 abstract description 4
- 239000006185 dispersion Substances 0.000 abstract description 2
- 239000011859 microparticle Substances 0.000 abstract 2
- 229920003986 novolac Polymers 0.000 abstract 1
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 16
- 239000000919 ceramic Substances 0.000 description 5
- 238000004519 manufacturing process Methods 0.000 description 5
- 239000007833 carbon precursor Substances 0.000 description 4
- 229960004011 methenamine Drugs 0.000 description 4
- 229920005989 resin Polymers 0.000 description 4
- 239000011347 resin Substances 0.000 description 4
- 239000002994 raw material Substances 0.000 description 3
- 238000005452 bending Methods 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 230000008021 deposition Effects 0.000 description 2
- 229910001873 dinitrogen Inorganic materials 0.000 description 2
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 238000009827 uniform distribution Methods 0.000 description 2
- 241000124033 Salix Species 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 230000005389 magnetism Effects 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 230000003014 reinforcing effect Effects 0.000 description 1
- 238000007873 sieving Methods 0.000 description 1
- 239000011863 silicon-based powder Substances 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 238000005728 strengthening Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000002912 waste gas Substances 0.000 description 1
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Abstract
The present invention relates to a method for the oxygen removal and the reinforcement of a solid phase organic precursor made of silicon nitride materials, which belongs to the ceramic material field. The method uses a reasonable process for changing novolac resins into a precursor of thermoset solid phase organic carbon to form a coating layer, and the precursor is uniformly coated at the particle surface of silicon nitride powder. The coating layer forms carbon micro particles uniformly dispersed at the coating layer in a pyrogenation course, the carbon micro particles generate dispersion reinforcement phase carborundum in the original position with oxygen containing phase silicon dioxide in silicon nitride powder in a sintering course, and oxygen escapes in the form of carbon monoxide gas. Materials prepared by the present invention have good strength and toughness.
Description
The invention relates to a preparation method of a silicon nitride ceramic material, belonging to the field of ceramic materials.
Silicon nitride ceramic material is an important aspect of high-tech ceramic material, is the most promising high-temperature resistant high-strength material, and can be used at the temperature as high as 1400 ℃ under the oxidizing atmosphere. Meanwhile, the alloy has the unique properties of low density, high hardness, chemical corrosion resistance, wear resistance, no magnetism and the like. Therefore, the ceramic bearing is the preferred material for high-temperature ceramic engines and high-temperature ultrahigh-speed ceramic bearings, and is also widely applied to metal cutting tools, ceramic parts in various corrosive environments and strong magnetic environments, and the like. Research shows that the increase of the oxygen content of the silicon nitride powder increases the crystal boundary glass phase, reduces the crystal boundary bonding strength and rapidly reduces the strength and the toughness of the product. However, the oxygen content of silicon nitride powder is not easily controlled due to manufacturing process. For this reason, in Journal of the Ceramic Society of Japan, page 764-768 of 1993, Liujinghong et al of Japan propose a method of pyrolysis with methane, in which carbon is plated on the surface of silicon nitride powder particles, so that the oxygen-containing phase silicon dioxide is converted into a reinforcing phase silicon carbide during sintering, and oxygen is released as carbon monoxide. Since carbon deposition is achieved by flowing methane gas through the silicon nitride powder sample, carbon deposition occurs not only on the surface of the silicon nitride powder particles, but also on the high temperature tube walls; in addition, the methane which is not pyrolyzed is discharged as waste gas. This results in a substantial reduction in methane utilization. Moreover, since the methane deposits carbon on the silicon nitride surface very slowly (the willow well known macro reports that the weight percentage of carbon deposited per hour is only 0.09%), the method is time-consuming, material-consuming and high in cost. In addition, if the amount of silicon nitride powder is increased (i.e., the volume is increased), it is extremely difficult to uniformly flow methane through the silicon nitride powder and uniformly deposit an equal amount of carbon in each portion of the powder. The above factors make this process difficult to put into practical production.
The invention aims to overcome the defect of using gas methane as a carbon source, and a solid-phase organic precursor converted from thermoplastic phenolic resin is used as the carbon source to remove oxygen in silicon nitride powder. The process is easy to control, the utilization rate of the carbon source is high, the carbon production speed is high, the cost is low, and the method can be put into practical production.
The invention comprises the following contents: the thermoplastic phenolic resin is converted into thermosetting and uniformly coated on the surface of the silicon nitride powder particles to form a solid-phase organic precursor coating layer. Then, under the protection of nitrogen gas making the above-mentioned coating layer implement pyrolysis to obtain uniformly-coated and dispersed carbon granules, and the above-mentioned carbon granules are mixed with nitrogen in the course of hot-pressing sintering processThe oxygen-containing phase silicon dioxide in the silicon powder generates particle reinforced phase silicon carbide in situ, and the oxygen escapes in the form of carbon monoxide gas, and the chemical reaction formula is . Because the uniformly dispersed reinforced phase silicon carbide particles are generated in situ in the silicon nitride matrix in the hot-pressing sintering process, the strength and the toughness of the silicon nitride are improved.
The invention isrealized by the following steps:
1. dissolving thermoplastic phenolic resin and hexamethylenetetramine in alcohol, adding silicon nitride powder into the solution, ball-milling and mixing, and drying;
2. heating the dried mixture to 200 ℃ and curing in the air for 1 hour;
3. placing the mixture cured in the step 2 in a quartz tube, gradually heating to 1000 ℃ in a nitrogen protective atmosphere, and carrying out pyrolysis to decompose carbon out of the resin and uniformly disperse the carbon on the surface of silicon nitride powder particles;
4. taking out the mixture obtained in the step 3 after cooling, adding sintering aids of alumina and yttrium oxide, and drying after ball milling in an alcohol medium;
5. placing the dried mixture in a graphite mold, and carrying out hot-pressing sintering at the temperature of 1600-1700 ℃ and the pressure of 20-30MPa under the protection of nitrogen so as to convert carbon into reinforced dispersed phase silicon carbide; while oxygen escapes as carbon monoxide. And cooling to obtain the high-strength and high-toughness silicon nitride product.
The amount of the thermoplastic phenolic resin added to the silicon nitride powder and then cured at 200 ℃ to form a solid organic carbon precursor depends on the carbon yield after pyrolysis and the oxygen content of the silicon nitride powder. The amount of carbon thermally liberated from the resin should not be too great to avoid the carbon from reacting completely to form free carbon which reduces the strength of the silicon nitride material. The dosage of the curing agent hexamethylene tetramine is 8-10% (weight percentage) of the dosage of the phenolic resin. The addition amounts of the sintering aids yttrium oxide and aluminum oxide are each 3 mol%.
The invention is characterized in that the carbon source adopts a thermosetting solid phase organic precursor converted from thermoplastic phenolic resin, so that the content of uniformly coated and dispersed carbon generated after pyrolysis is conveniently controlled by the addition of thermoplastic organic matters, rather than by the pyrolysis time. The unique process of dispersing and coating the solution and then curing ensures the uniform distribution of the organic precursor as a carbon source in the silicon nitride powder, thereby ensuring the uniform coating dispersion of the pyrolyzed carbon in the silicon nitride powder. This uniformity is not affected by the amount of silicon nitride powder. The thermosetting treatment process ensures that the organic carbon precursor is not melted and settled in the high-temperature pyrolysis process, and ensures that the uniform distribution of the organic carbon precursor in the silicon nitride powder is not changed all the time.
The silicon nitride ceramic material produced by coating the thermosetting solid-phase organic carbon precursor with the thermoplastic phenolic resin has the advantages of high utilization rate of raw materials, simple treatment equipment, easily controlled process and low cost, is easy to realize uniform coating treatment on a large amount of silicon nitride powder, and is easy to put into practical production.
Example (b):
example 1. taking 1.306 g of thermoplastic phenolic resin and 0.112 g of hexamethylenetetramine, dissolving and spraying, adding 70 g (average particle size of 1 μm) of silicon nitride powder with the oxygen content of 3.18% (weight percentage), ball milling for 24 hours, drying, curing the resin in air at 200 ℃ for 1 hour, and then placing the resin in a quartz tube for pyrolysis treatment. And (3) carrying out pyrolysis under the protection of 25 ml/min flowing nitrogen, heating at the speed of 2 ℃/min to 1000 ℃, preserving heat for 5 hours, and then cooling. Taking out, respectively adding 2.58 g and 1.16 g of yttrium oxide and alumina powder, ball-milling in a wine clear medium for 24 hours, taking out, drying, sieving with a 60-mesh sieve, placing in a graphite mold, and introducing nitrogen gas at 1atmProtecting, sintering under 20MPa and 1650 ℃ for 1 hour. The bending strength of the obtained material is 908.9MPa, and the fracture toughness is 8.46MPam1/2。
Example 2. the raw material source and preparation process are the same as example 1, and the raw material formula is as follows: 0.914 g of thermoplastic phenolic resin, 0.079 g of hexamethylenetetramine, 70 g of silicon nitride powder, and 1.16 g of aluminum oxide powder and 2.58 g of yttrium oxide powder respectively. The bending strength of the prepared material is 812.3MPa, and the fracture toughness is 8.72MPam1/2。
Claims (1)
1. A silicon nitride material solid phase organic precursor deoxygenization enhancement method, plate carbon on the surface of the silicon oxide powder particle, make the silicon dioxide of oxygen-containing phase change into the silicon carbide of enhanced phase in the course of sintering, characterized by that to use the solid phase organic precursor carbon source that the thermoplastic phenolic resin changes into thermosetting and cover on the surface of the silicon nitride powder particle evenly, form the organic precursor coating of solid phase, then, make the above-mentioned coating pyrolyze out and cover the scattered carbon microgranule under the protection of nitrogen, the above-mentioned carbon microgranule and silicon dioxide of oxygen-containing phase in the silicon nitride powder produce the silicon carbide of particle enhanced phase in situ in the course of hot-pressing sintering, its process step is as follows:
(1) dissolving thermoplastic phenolic resin and hexamethylenetetramine in alcohol, wherein the using amount of the hexamethylenetetramine is 8-10% (weight percentage) of that of the phenolic resin, adding silicon nitride powder into the mixed solution, performing ball milling and mixing, and drying a mixture after ball milling;
(2) heating the dried mixture to 200 ℃, and curing in the air for 1 hour;
(3) placing the mixture cured in the step (2) in a quartz tube, and gradually heating to 1000 ℃ under the protection of nitrogen for pyrolysis to uniformly disperse carbon decomposed from the phenolic resin on the surface of silicon nitride powder particles;
(4) taking out the mixture obtained in the step (3) after cooling, adding sintering aids of alumina and yttrium oxide, performing ball milling in an alcohol medium, and drying, wherein the molar percentage content of the alumina and the yttrium oxide is 3 percent respectively;
(5) and (4) placing the dried mixture in the step (4) in a graphite die, and carrying out hot-pressing sintering under the protection of nitrogen, wherein the temperature of the hot-pressing sintering is 1600-1700 ℃, the pressure is 20-30MPa, carbon is converted into reinforced dispersed-phase silicon carbide, oxygen escapes in the form of carbon monoxide, and the silicon nitride ceramic material is obtained after the hot-pressing sintering.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN97119087A CN1057515C (en) | 1997-10-24 | 1997-10-24 | Method for deoxidisation and reinforcement of solid organic procursor of silicon nitride material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN97119087A CN1057515C (en) | 1997-10-24 | 1997-10-24 | Method for deoxidisation and reinforcement of solid organic procursor of silicon nitride material |
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| Publication Number | Publication Date |
|---|---|
| CN1215710A CN1215710A (en) | 1999-05-05 |
| CN1057515C true CN1057515C (en) | 2000-10-18 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN97119087A Expired - Fee Related CN1057515C (en) | 1997-10-24 | 1997-10-24 | Method for deoxidisation and reinforcement of solid organic procursor of silicon nitride material |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN112517906B (en) * | 2020-12-17 | 2023-06-20 | 滨州学院 | Aluminum-based composition for additive manufacturing, preparation method and application thereof |
| CN115745625A (en) * | 2022-12-02 | 2023-03-07 | 合肥圣达电子科技实业有限公司 | High-thermal-conductivity silicon nitride substrate and preparation method thereof |
| CN116217242B (en) * | 2022-12-29 | 2024-02-09 | 兴核科学研究(福建)有限责任公司 | Preparation method of silicon nitride ceramic slurry suitable for photo-curing forming process |
| CN117229067B (en) * | 2023-11-14 | 2024-02-23 | 中南大学 | Method for preparing silicon nitride ceramics by low-pressure nitridation-embedding |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0082343A1 (en) * | 1981-11-25 | 1983-06-29 | Kabushiki Kaisha Toshiba | Process for preparing silicon nitride powder |
| EP0133874A1 (en) * | 1983-06-30 | 1985-03-13 | Mtu Motoren- Und Turbinen-Union MàNchen Gmbh | Process for the hot isostatic pressing of shaped ceramic parts |
| CN1052652A (en) * | 1991-02-04 | 1991-07-03 | 冶金工业部钢铁研究总院 | Making method of crystal whisker excess weld metal silicon nitride compound material |
-
1997
- 1997-10-24 CN CN97119087A patent/CN1057515C/en not_active Expired - Fee Related
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0082343A1 (en) * | 1981-11-25 | 1983-06-29 | Kabushiki Kaisha Toshiba | Process for preparing silicon nitride powder |
| EP0133874A1 (en) * | 1983-06-30 | 1985-03-13 | Mtu Motoren- Und Turbinen-Union MàNchen Gmbh | Process for the hot isostatic pressing of shaped ceramic parts |
| CN1052652A (en) * | 1991-02-04 | 1991-07-03 | 冶金工业部钢铁研究总院 | Making method of crystal whisker excess weld metal silicon nitride compound material |
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| CN1215710A (en) | 1999-05-05 |
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