CN102537510B - Pressureless sintering silicon carbide ceramic valve core and preparation process thereof - Google Patents
Pressureless sintering silicon carbide ceramic valve core and preparation process thereof Download PDFInfo
- Publication number
- CN102537510B CN102537510B CN201010618710.2A CN201010618710A CN102537510B CN 102537510 B CN102537510 B CN 102537510B CN 201010618710 A CN201010618710 A CN 201010618710A CN 102537510 B CN102537510 B CN 102537510B
- Authority
- CN
- China
- Prior art keywords
- valve core
- silicon carbide
- sintering
- preparation process
- mentioned
- 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
Abstract
The invention relates to a preparation process of a ceramic valve core, in particular to a pressureless sintering silicon carbide ceramic valve core and a preparation process of the silicon carbide ceramic valve core. The preparation process comprises the following steps of raw material preparation, spray granulation, die filling, pressure forming, baking, coarse processing, high-temperature sintering, fine processing to the dimension, and obtaining of finished products of the valve core and a valve seat. The silicon carbide ceramic valve core prepared by the process has the density higher than 3.13g/cm<3>, the bending strength higher than or equal to 400Mpa, the hardness being 2000HV, the elastic modulus higher than 410Gpa and the fracture toughness higher than or equal to 4MPa*M<1/2>. The technical scheme provided by the invention has the advantages that the mold design and processing difficulty and the mold number can be greatly reduced, the processing quantity after the high-temperature sintering can be effectively reduced, the processing cost can be effectively lowered, and the density and the uniformity of the valve core and the valve seat can be effectively ensured. The valve core and the valve seat prepared by the process have all good performance of silicon carbide ceramic materials, and the preparation process is particularly suitable for preparing the valve core and the valve seat of ceramic materials in various appearances.
Description
Technical field
Patent of the present invention relates to the preparation process of ceramic valve core, particularly a kind of silicon carbide ceramic valve core and preparation process thereof who utilizes pressureless sintering.
Background technique
technology
Valve is by the relative position of spool in valve, regulate flow, pressure and the liquid level of medium, usually said spool to comprise valve seat and form with the spool that valve seat matches.Corrosion is the difficult problem that in chemical industry, valve series products is faced with washing away.Logistics in pipeline is high temperature, high pressure, at a high speed not only, and be mingled with hard particles, very serious to the erosive wear of spool, valve seat, caused close dead, do not open, leak large, the use problem such as sealing reliability is poor, working life is short, be domestic and international producer problem in the urgent need to address.The valve seat, the spool that at present a lot of valves, match all adopt ceramic material, but it is processed after making and all adopting high temperature sintering, due to features such as the hardness of stupalith is large, poor toughness, make the difficulty of processing itself just very large, although be to adopt precision press-molding manufacture before sintering, but the machining allowance after its sintering is large, cause the cost of production of product high, the problem such as the up-to-standard rate of product is low.
Summary of the invention
The object of this invention is to provide that a kind of machining allowance is little, cost of production is low, the good pressureless sintering silicon carbide ceramic valve core of various technical orders and the preparation process thereof of final products.
For realizing object of the present invention, the technological scheme adopting is: a kind of preparation process of pressureless sintering silicon carbide ceramic valve core, and this preparation process's step is:
1) configuration of raw material: be 80～100 parts of silicon carbide, 0.1～1 part of boron carbide powder, 0.5～3 part of polyvinyl alcohol, appropriate dispersing agent, 0.1～1 part of water-soluble polyoxyethylene resin by weight percentage, put into 100～150 parts of deionized waters, mix and form water base compound slip;
2) mist projection granulating, dress mould, pressure forming: by after above-mentioned water base compound slip mist projection granulating, cross after 200 mesh sieves, the particle after sieving is packed in mould, compressing under the pressure of 140～200MPa, obtain spool and valve body base substrate;
3) oven dry, roughing: above-mentioned base substrate is dried 1-3 hours under the condition of≤300 ℃, cool to room temperature with the furnace, obtain setting up the biscuit of initial strength, biscuit is carried out to roughing by the shape of spool and valve body, size;
4) high temperature sintering: the spool after above-mentioned roughing and valve body are put into sintering furnace, be heated to 2000 ℃～2100 ℃ sinter moldings;
5) spool after above-mentioned high temperature sintering moulding and valve body are refined to figure paper size, obtain spool, the valve seat of finished product.
The index of above-mentioned silicon carbide is: granularity D
50≤ 0.6 μ m, specific surface area > 13m
2/ g, purity>=98%.
The granularity of above-mentioned boron carbide powder is less than 200 orders.
Above-mentioned dispersing agent is polyethyleneglycol or ammoniacal liquor or amino alcohol.
The pH value of above-mentioned water base compound slip is 9-10, and pH value is to adjust by above-mentioned dispersing agent.
In above-mentioned high temperature sintering, spool and valve body are put into after sintering furnace, vacuumize the degree of vacuum < 10 making in sintering furnace
-2after mbar, be filled with argon gas, carry out sintering under argon shield, warming velocity during sintering is 0.5～8 ℃/min, is warming up to 2000 ℃～2100 ℃, after being incubated 1 hour～1.5 hours, cools to room temperature with the furnace, then is refined to figure paper size.
Pressureless sintering silicon carbide ceramic valve core, is characterized in that its density > 3.13g/cm
3, resistance to flexure>=400Mpa, hardness 2000 HV, elastic modulus G reatT.GreaT.GT 410Gpa, fracture toughness>=4MPaM
1/2.
The feature of technological scheme of the present invention is as follows:
1) adopt the raw material configuring is compressing after, low-temperature bake, carries out roughing by the biscuit of setting up initial strength, the surplus after roughing is to guarantee the contour projector of rear step high temperature sintering.Because the work hardness of product before high temperature sintering is lower, roughing is very easy to, can effectively reduce the amount of finish after high temperature sintering simultaneously and reduce processing charges.
2) because this technique is that the biscuit after drying before high temperature sintering has been carried out to roughing, after high temperature sintering, can effectively guarantee density and the uniformity of final products-spool and valve body like this.
3) spool of preparing by this technique and valve body have possessed all premium properties of thyrite, operating temperature can reach 1200 ℃, be up to 1600 ℃, resistance to various strong acid, alkali corrosion, the high decades of times of resistance to erosion energy force rate metal, is particularly suitable for the spool of thyrite and the preparation of valve seat of various shapes.
Accompanying drawing explanation
Accompanying drawing 1 is process flow diagram of the present invention.
Embodiment
Fig. 1 is process flow diagram of the present invention, according to the embodiment of technological process, sees following specific embodiment.
Embodiment 1:
Take 80 ㎏ granularity D
50=0.6 μ m, specific surface area: 14m
2/ g left and right, the carborundum powder of purity=98%, 0.1 ㎏ granularity is less than 200 object boron carbide powders, 0.5 ㎏ polyvinyl alcohol and 0.1 ㎏ water-soluble polyoxyethylene resin, add 100 ㎏ deionized waters, in pebble mill, mix, the pH value of adjusting above-mentioned water base compound slip with macrogol is 9 left and right, after mixing and all using, by water base compound slip mist projection granulating, cross after 200 mesh sieves, pack in mould, compressing under the pressure of 140MPa, obtain spool and valve body base substrate.Base substrate is put into baking oven and dry, control bake out temperature 280 ℃ of left and right, drying time 1 hour, carries out roughing by drawing after cooling to room temperature with the furnace.Rough machined workpiece is put into sintering furnace, be heated to 2000 ℃ of left and right high temperature sintering moulding; The design parameter of above-mentioned high temperature sintering moulding is: vacuumize the degree of vacuum < 10 making in sintering furnace
-2after mbar, be filled with argon gas, carry out sintering under argon shield, warming velocity during sintering is 0.5/min, is warming up to 2000 ℃, is incubated after 1.5 hours, cools to room temperature with the furnace, then is refined to figure paper size, is core and the valve body of finished product.
By detecting, the density of core and valve body and uniformity are very unified.Its density: 3.13-3.15g/cm
3, resistance to flexure: 410Mpa, hardness: 2000 HV, Young's modulus: 410Gpa, fracture toughness: 4.1MPaM
1/2
Embodiment 2-4:
On the basis of above-described embodiment 1, feed change proportioning and process parameter, concrete raw material proportioning sees the following form 1, and process parameter sees the following form 2:
Table 1
Table 2
| Embodiment | The pressure of moulding | Bake out temperature | High temperature sintering temperature | Warming velocity | Holding time |
| Embodiment 2 | 200MPa | 3 hours | 2100℃ | 8℃/min | 1 hour |
| Embodiment 3 | 160MPa | 2 hours | 2050℃ | 4℃/min | 1.2 hour |
In above-described embodiment 2,3, the pH value that adopts the pure ammoniacal liquor of analysis and amino alcohol to adjust above-mentioned water base compound slip is respectively 9 and 10 left and right.
By detecting, the density of core and valve body and uniformity are very unified.Its density is respectively 3.13 g/cm
3and 3.14g/cm
3, resistance to flexure: 410Mpa, hardness: 2010 HV, Young's modulus: 400Gpa, fracture toughness: 4.1MPaM
1/2.
Claims (4)
1. a preparation process for pressureless sintering silicon carbide ceramic valve core, this preparation process's step is:
1) configuration of raw material: by weight percentage be 80～100 parts, granularity D
50≤ 0.6 μ m, specific surface area > 13m
2the silicon carbide of/g, purity>=98%, 0.1～1 part, granularity is less than 200 object boron carbide powders, 0.5～3 part of polyvinyl alcohol, appropriate dispersing agent, and 0.1～1 part of water-soluble polyoxyethylene resin, put into 100～150 parts of deionized waters, mix and form water base compound slip;
2) mist projection granulating, dress mould, pressure forming: by above-mentioned water base compound slip mist projection granulating, cross after 200 mesh sieves, pack in mould, compressing under the pressure of 140～200MPa, obtain spool and valve body base substrate;
3) oven dry, roughing: above-mentioned base substrate is dried 1～3 hour under the condition of 280 ℃～300 ℃, cool to room temperature with the furnace, obtain setting up the biscuit of initial strength, biscuit is carried out to roughing by the shape of spool and valve body, size;
4) high temperature sintering: the spool after above-mentioned roughing and valve body are put into sintering furnace, be heated to 2000 ℃～2100 ℃, sinter molding under argon shield; The concrete technology of above-mentioned sinter molding is: in high temperature sintering, the spool after above-mentioned roughing and valve body are put into after sintering furnace, vacuumized the degree of vacuum < 10 making in sintering furnace
-2after mbar, be filled with argon gas, carry out sintering under argon shield, warming velocity during sintering is 0.5 ℃/min, is warming up to 2000 ℃～2100 ℃, after being incubated 1 hour～1.5 hours, cools to room temperature with the furnace;
5) spool after above-mentioned high temperature sintering moulding and valve body are refined to figure paper size, obtain spool, the valve body of finished product.
2. the preparation process of pressureless sintering silicon carbide ceramic valve core according to claim 1, is characterized in that above-mentioned dispersing agent is polyethyleneglycol or ammoniacal liquor or amino alcohol.
3. the preparation process of pressureless sintering silicon carbide ceramic valve core according to claim 2, the pH value that it is characterized in that above-mentioned water base compound slip is 9-10, pH value is to adjust by above-mentioned dispersing agent.
4. according to the prepared pressureless sintering silicon carbide ceramic valve core of the preparation process of above-mentioned arbitrary claim, it is characterized in that: its density is 3.13-3.15g/cm
3, resistance to flexure>=400Mpa, hardness 2000 HV, elastic modulus G reatT.GreaT.GT 410Gpa, fracture toughness>=4MPaM
1/2, operating temperature can reach 1200 ℃～1600 ℃.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201010618710.2A CN102537510B (en) | 2010-12-31 | 2010-12-31 | Pressureless sintering silicon carbide ceramic valve core and preparation process thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201010618710.2A CN102537510B (en) | 2010-12-31 | 2010-12-31 | Pressureless sintering silicon carbide ceramic valve core and preparation process thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102537510A CN102537510A (en) | 2012-07-04 |
| CN102537510B true CN102537510B (en) | 2014-03-19 |
Family
ID=46345134
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201010618710.2A Active CN102537510B (en) | 2010-12-31 | 2010-12-31 | Pressureless sintering silicon carbide ceramic valve core and preparation process thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102537510B (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103433478A (en) * | 2013-08-22 | 2013-12-11 | 青岛云路新能源科技有限公司 | Nozzle for producing amorphous alloy strip and manufacturing method thereof |
| CN105000906A (en) * | 2015-06-24 | 2015-10-28 | 左然 | Pressurelessly-sintered silicon carbide foamed ceramic and preparation method thereof |
| CN106838407A (en) * | 2016-12-29 | 2017-06-13 | 无锡刚正精密吸铸有限公司 | A kind of valve of high temperature resistant, high reliability |
| CN108083809A (en) * | 2017-12-12 | 2018-05-29 | 沈阳化工大学 | A kind of preparation method of metallurgy valve spool of valve and liner |
| CN108329035A (en) * | 2018-02-06 | 2018-07-27 | 中国科学院上海硅酸盐研究所 | Silicon carbide ceramic valve core and preparation method thereof |
| CN109095927A (en) * | 2018-08-07 | 2018-12-28 | 山东金德新材料有限公司 | A kind of pressureless sintering silicon carbide microchannel reactor chip and preparation method thereof |
| CN111848174A (en) * | 2020-07-30 | 2020-10-30 | 山东中鹏特种陶瓷有限公司 | Method for producing wear-resistant silicon carbide ceramic block based on press machine |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101077838A (en) * | 2006-05-23 | 2007-11-28 | 宁波大学 | Technique for preparing liquid phase sintering silicon carbide ceramic |
| CN101081740A (en) * | 2007-04-24 | 2007-12-05 | 山东金鸿集团有限公司 | Process for production of reaction-sintered silicon carbide |
| CN101555143A (en) * | 2009-05-12 | 2009-10-14 | 宁波欧翔精细陶瓷技术有限公司 | Preparation method of normal pressure-sintered silicon carbide ceramics |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2007056895A1 (en) * | 2005-11-18 | 2007-05-24 | Institute Of Metal Research Chinese Academy Of Sciences | Compact foamed thyrite with high intensity and preparation method of the same |
-
2010
- 2010-12-31 CN CN201010618710.2A patent/CN102537510B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101077838A (en) * | 2006-05-23 | 2007-11-28 | 宁波大学 | Technique for preparing liquid phase sintering silicon carbide ceramic |
| CN101081740A (en) * | 2007-04-24 | 2007-12-05 | 山东金鸿集团有限公司 | Process for production of reaction-sintered silicon carbide |
| CN101555143A (en) * | 2009-05-12 | 2009-10-14 | 宁波欧翔精细陶瓷技术有限公司 | Preparation method of normal pressure-sintered silicon carbide ceramics |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102537510A (en) | 2012-07-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102537510B (en) | Pressureless sintering silicon carbide ceramic valve core and preparation process thereof | |
| CN106747457B (en) | A kind of preparation method and its accurate SiC ceramic of the accurate SiC ceramic based on silica gel mould gel casting forming | |
| CN105478776B (en) | A kind of method that low-temperature sintering prepares high-compactness pure tungsten product | |
| CN109877329B (en) | Preparation of titanium and titanium alloy powder for 3D printing based on fluidized bed jet mill technology | |
| CN101214546A (en) | Method for preparing powder metallurgy of titanium-aluminium alloy target material | |
| CN103643067B (en) | A kind of nanometer silicon carbide strengthens metal-base composites and preparation method thereof | |
| CN109482813B (en) | WCp/EPS lost foam pattern and WCp/Fe composite material preparation | |
| CN109467436B (en) | Boron carbide ceramic ball and preparation method thereof | |
| CN110330345B (en) | Silicon nitride ceramic material, preparation method thereof and ceramic mold | |
| CN107398559A (en) | A kind of powder injection-molded method of large parts for support of arranging in pairs or groups | |
| CN107498056A (en) | A kind of Kato production technology | |
| WO2022134402A1 (en) | Ceramic cutting tool having chip breaking groove and preparation method therefor | |
| CN100506486C (en) | Shaft grinding abrasive wheel | |
| CN112427641A (en) | Preparation method of mobile phone middle plate jig | |
| CN110483056B (en) | Preparation method of silicon carbide ceramic ball | |
| CN105437089A (en) | Sapphire thinning diamond resin grinding wheel and preparation method | |
| CN106518088A (en) | Manufacturing method of high-performance silicon nitride sealing ring | |
| WO2020038414A1 (en) | Cemented carbide indexable cutting insert of layered structure and manufacturing method therefor | |
| CN107986787B (en) | Formula and preparation method of low-temperature sintered ceramic diamond grinding head | |
| CN104211407A (en) | Process for forming large-size complex-shaped silicon carbide ceramic biscuit | |
| CN111778436B (en) | Method for preparing WC-Y2O3 binderless hard alloy by cold pressing-hot pressing sintering | |
| CN103056369A (en) | Process for producing part by powder metallurgy | |
| CN1061580C (en) | Method for making sintered alloy balls | |
| CN106078486A (en) | A kind of honing stone for machining steel thin wall chromate treatment cylinder sleeve | |
| CN103045167A (en) | Magnetic grinding material 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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| ASS | Succession or assignment of patent right |
Owner name: NINGXIA MACHINERY RESEARCH INSTITUTE CO., LTD. Free format text: FORMER OWNER: ZHANG GUANGRONG Effective date: 20150429 |
|
| C41 | Transfer of patent application or patent right or utility model | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20150429 Address after: 750002 Machinery Research Institute, No. 17 Road, hi tech Development Zone, Jinfeng District, the Ningxia Hui Autonomous Region, Yinchuan Patentee after: NINGXIA MACHINERY RESEARCH INSTITUTE CO., LTD. Address before: 750002 Machinery Research Institute, No. 17 Road, hi tech Development Zone, Jinfeng District, the Ningxia Hui Autonomous Region, Yinchuan Patentee before: Zhang Guangrong |