JPH0283260A - Production of sintered silicon carbide - Google Patents
Production of sintered silicon carbideInfo
- Publication number
- JPH0283260A JPH0283260A JP63232263A JP23226388A JPH0283260A JP H0283260 A JPH0283260 A JP H0283260A JP 63232263 A JP63232263 A JP 63232263A JP 23226388 A JP23226388 A JP 23226388A JP H0283260 A JPH0283260 A JP H0283260A
- Authority
- JP
- Japan
- Prior art keywords
- silicon carbide
- atmosphere
- oxidizing atmosphere
- sintered
- sintered body
- 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.)
- Pending
Links
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 title claims abstract description 28
- 229910010271 silicon carbide Inorganic materials 0.000 title claims abstract description 26
- 238000004519 manufacturing process Methods 0.000 title claims description 6
- 239000012298 atmosphere Substances 0.000 claims abstract description 20
- 230000001590 oxidative effect Effects 0.000 claims abstract description 13
- 239000002994 raw material Substances 0.000 claims abstract description 4
- 238000000465 moulding Methods 0.000 claims abstract 2
- 238000000034 method Methods 0.000 claims description 4
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 abstract description 19
- 230000003647 oxidation Effects 0.000 abstract description 15
- 238000007254 oxidation reaction Methods 0.000 abstract description 15
- 235000012239 silicon dioxide Nutrition 0.000 abstract description 8
- 239000000377 silicon dioxide Substances 0.000 abstract description 8
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 abstract description 7
- 238000010438 heat treatment Methods 0.000 abstract description 7
- 239000001301 oxygen Substances 0.000 abstract description 7
- 229910052760 oxygen Inorganic materials 0.000 abstract description 7
- 239000011148 porous material Substances 0.000 abstract description 6
- 239000011248 coating agent Substances 0.000 abstract description 3
- 238000000576 coating method Methods 0.000 abstract description 3
- 239000000463 material Substances 0.000 abstract 4
- 238000001354 calcination Methods 0.000 abstract 1
- 238000010304 firing Methods 0.000 description 5
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 4
- 229910052710 silicon Inorganic materials 0.000 description 4
- 239000010703 silicon Substances 0.000 description 4
- 229910052814 silicon oxide Inorganic materials 0.000 description 3
- 238000005266 casting Methods 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 239000002002 slurry Substances 0.000 description 2
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 239000012300 argon atmosphere Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 229910052796 boron Inorganic materials 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 238000003763 carbonization Methods 0.000 description 1
- 239000011362 coarse particle Substances 0.000 description 1
- 229910052681 coesite Inorganic materials 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 229910052906 cristobalite Inorganic materials 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 239000011505 plaster Substances 0.000 description 1
- 238000013001 point bending Methods 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000035939 shock Effects 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 229910052682 stishovite Inorganic materials 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 229910052905 tridymite Inorganic materials 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Ceramic Products (AREA)
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は、高温用構造部材として好適に使用可能な耐酸
化性に優れた炭化珪素焼結体の製造法に関するものであ
る。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for producing a silicon carbide sintered body having excellent oxidation resistance and suitable for use as a high-temperature structural member.
（従来の技術）
高純度炭化珪素の焼結体は、高温での強度が高く、熱伝
導性、耐熱衝撃性等の特性が優れているので、高温用構
造部材として使用されている。しかし、高純度炭化珪素
焼結体を高温の酸化雰囲気中で使用する場合、炭化珪素
と酸素とが反応して酸化珪素を生成し、使用中に強度低
下を示す問題があった。(Prior Art) Sintered bodies of high-purity silicon carbide have high strength at high temperatures and excellent properties such as thermal conductivity and thermal shock resistance, so they are used as structural members for high temperatures. However, when a high-purity silicon carbide sintered body is used in a high-temperature oxidizing atmosphere, there is a problem in that silicon carbide and oxygen react to form silicon oxide, resulting in a decrease in strength during use.
そのため従来は、高純度の炭化珪素粉末にホウ素、炭素
源の焼結助剤を添加してち密化する方法、または炭化珪
素の微粉と粗粉とを成形焼成し再結晶させた焼結体を製
造し、この焼結体に形成させた開気孔に珪素を含浸させ
てち密化する方法により、耐酸化性を増加させ酸化珪素
の生成を防止していた。Therefore, conventional methods have been used to densify high-purity silicon carbide powder by adding sintering aids such as boron and carbon sources, or to form and sinter fine silicon carbide powder and coarse powder to recrystallize the sintered body. By impregnating the open pores formed in this sintered body with silicon to densify it, the oxidation resistance was increased and the formation of silicon oxide was prevented.
（発明が解決しようとする課題）
しかしながら、前者の方法では、高温の真空又は不活性
雰囲気で焼成し、高密度、高強度で耐酸化性に優れたも
のを得ることができるが、焼成中に大きな収縮が生じる
ため、大型で複雑な形状の焼結体を得ることができない
問題があった。(Problem to be solved by the invention) However, in the former method, it is possible to obtain a product with high density, high strength, and excellent oxidation resistance by firing in a high-temperature vacuum or inert atmosphere, but during firing, Since large shrinkage occurs, there is a problem in that it is not possible to obtain a sintered body with a large size and a complicated shape.
また、後者の方法においては、焼結体の開気孔中に高温
温度下で熔融珪素又は、蒸気状態の珪素を含浸すること
により、高強度でち密な焼結体を得ることができるが、
処理費用や設備が大規模となり、コストの面で問題があ
った。In the latter method, a high-strength and dense sintered body can be obtained by impregnating molten silicon or vaporized silicon into the open pores of the sintered body at high temperatures.
There were problems in terms of cost, as processing costs and equipment were large-scale.
本発明の目的は上述した課題を解消し、簡単かつ安価に
大型で複雑な形状の高温用構造部材を得ることができる
耐酸化性に優れた炭化珪素焼結体の製造法を提供し７よ
うとするものである。An object of the present invention is to solve the above-mentioned problems and provide a method for manufacturing a silicon carbide sintered body with excellent oxidation resistance, which can easily and inexpensively produce large-sized, complex-shaped high-temperature structural members. That is.
（課題を解決するための手段）
本発明の炭化珪素焼結体の製造法は、炭化珪素含有率９
５％以上の炭化珪素原料を鋳込み成形または押し出し成
形して得た成形体を、２０００℃以上の非酸化雰囲気で
焼成した後、１０００’Ｃ以上１５００’Ｃ以下の酸化
雰囲気で熱処理することを特徴とするものである。(Means for Solving the Problems) The method for producing a silicon carbide sintered body of the present invention has a silicon carbide content of 9
A molded body obtained by casting or extrusion molding of 5% or more silicon carbide raw material is fired in a non-oxidizing atmosphere at 2000°C or higher, and then heat-treated in an oxidizing atmosphere at 1000°C or higher and 1500°C or lower. That is.
（作 用）
上述した構成において、−旦非酸化性雰囲気中で本焼成
を行なって焼結体を得た後、この焼結体に対して所定温
度かつ所定雰囲気の熱処理を行なうことにより、炭化珪
素焼結体の開気孔の内面に均一な二酸化珪素の被膜が形
成されるので、この焼結体を高温の酸化雰囲気中で使用
する場合でも雰囲気中の酸素が遮断されて、焼結体内部
の炭化珪素の酸化を防止することができる。(Function) In the above-mentioned configuration, after first performing main firing in a non-oxidizing atmosphere to obtain a sintered body, this sintered body is heat-treated at a predetermined temperature and in a predetermined atmosphere to cause carbonization. A uniform silicon dioxide coating is formed on the inner surface of the open pores of the silicon sintered body, so even when this sintered body is used in a high-temperature oxidizing atmosphere, oxygen in the atmosphere is blocked and the inside of the sintered body is The oxidation of silicon carbide can be prevented.
すなわち、酸化雰囲気での熱処理は、再結晶炭化珪素に
形成される開気孔の内面を以下の式で示される反応によ
り生成する二酸化珪素被覆で覆うようにして、耐酸化性
の向上した焼結体を得ている。In other words, heat treatment in an oxidizing atmosphere covers the inner surfaces of open pores formed in recrystallized silicon carbide with a silicon dioxide coating produced by the reaction shown by the following formula, resulting in a sintered body with improved oxidation resistance. I am getting .
ＳｉＣ＋２０□ →ＳｉＯ２＋ ＣＯ□熱処理温度は１
０００℃〜１５００℃であるが、望ましくは１２００’
Ｃ〜１４００℃の範囲内であると好適である。SiC+20□ →SiO2+ CO□Heat treatment temperature is 1
000°C to 1500°C, preferably 1200'
It is suitable that it is within the range of C to 1400C.
１０００’Ｃ未満の温度では酸化珪素の生成が少なく、
また二酸化珪素もガラス化せず開気孔の内面を覆う均一
な被膜が形成されないため効果が少ないとともに、１５
００℃を越える温度では生成した二酸化珪素が変態して
体積変化を生じ生成した被膜にクラックが生じるため、
活発な酸化を起して強度低下を起すので、熱処理温度を
１０００℃〜１５００℃と限定した。At temperatures below 1000'C, less silicon oxide is produced,
Silicon dioxide also has little effect because it does not vitrify and does not form a uniform film covering the inner surface of open pores.
At temperatures exceeding 00°C, the produced silicon dioxide transforms and changes in volume, causing cracks in the produced film.
Since active oxidation occurs and strength decreases, the heat treatment temperature was limited to 1000°C to 1500°C.
また、酸化雰囲気の酸素濃度は１〜２０％の範囲が好ま
しい。酸素濃度が１％未満の場合は二酸化珪素の被膜形
成の反応が遅く、また、焼結体の厚さ方向中心部で二酸
化珪素の被膜が形成されない場合が生じるなど充分均一
な被膜の１７さを得られない場合があるとともに、２０
％を越えると活発な酸化が起り生成した被膜にクラック
が生じる場合があるためである。Further, the oxygen concentration of the oxidizing atmosphere is preferably in the range of 1 to 20%. If the oxygen concentration is less than 1%, the reaction to form a silicon dioxide film is slow, and the silicon dioxide film may not be formed in the center of the thickness of the sintered body, making it difficult to form a sufficiently uniform film. In some cases, it may not be possible to obtain 20
%, active oxidation may occur and cracks may occur in the resulting film.
（実施例） 以下、実際の例について説明する。(Example) An actual example will be explained below.
第１表に示す炭化珪素含有率の炭化珪素の粗粒（平均粒
径１５０μｍ）と微粒（平均粒径３．５μｍ）とを、１
：１の９１合で配合して水を１５重量％添加し、これを
ポットミルで混合して泥漿を作製した。この泥漿を石膏
型へ鋳込んで得た成形体を、アルゴン雰囲気中、２３０
０℃の温度で焼成して炭化珪素焼結体を得た。Coarse particles (average particle size 150 μm) and fine particles (average particle size 3.5 μm) of silicon carbide having the silicon carbide content shown in Table 1 were
A slurry was prepared by adding 15% by weight of water and mixing in a pot mill. The molded body obtained by casting this slurry into a plaster mold was heated at 230 °C in an argon atmosphere.
A silicon carbide sintered body was obtained by firing at a temperature of 0°C.
得られた焼結体に対して、第１表に示す酸素濃度および
熱処理温度で熱処理を実施した。熱処理後の焼結体に対
してＪＩＳ Ｒ１６０１に基く４点曲げ試験を実施する
とともに、耐酸化性を評価した。結果を第１表に示す。The obtained sintered bodies were heat treated at the oxygen concentrations and heat treatment temperatures shown in Table 1. The sintered body after the heat treatment was subjected to a four-point bending test based on JIS R1601, and its oxidation resistance was evaluated. The results are shown in Table 1.
第１表において、耐酸化性の評価は、焼結体を大気中１
３００℃で１０００時間保持したときの１時間当たりの
重量増加率（１０弓％）により実施した。In Table 1, the evaluation of oxidation resistance is as follows:
The weight increase rate (10 bow%) per hour was determined when the temperature was maintained at 300° C. for 1000 hours.
男Ｉ表
第１表の結果から、本発明の条件をすべて満たす実施倒
動、１〜６は、いずれかの条件を満たしていない比較例
Ｎｏ、 １〜６と比べて、強度が強いとともに、重量増
加率は少な（耐酸化性が良好であることがわかる。From the results in Table 1 of Table 1, it can be seen that Examples 1 to 6, which meet all the conditions of the present invention, have stronger strength than Comparative Examples Nos. 1 to 6, which do not meet any of the conditions. The weight increase rate is small (it can be seen that the oxidation resistance is good).
（発明の効果）
以上の説明から明らかなように、本発明の耐酸化性に優
れた炭化珪素焼結体の製造法によれば、−見本焼成を行
なって焼結体を得た後、この焼結体に対して所定温度か
つ所定雰囲気の熱処理を行なうことにより、簡単な方法
で耐酸化性に優れた炭化珪素焼結体を得ることができる
。(Effects of the Invention) As is clear from the above explanation, according to the method for producing a silicon carbide sintered body with excellent oxidation resistance of the present invention, - After performing sample firing to obtain a sintered body, By subjecting the sintered body to heat treatment at a predetermined temperature and in a predetermined atmosphere, a silicon carbide sintered body having excellent oxidation resistance can be obtained in a simple manner.
特 許 出 願 人 日本碍子株式会社Special permission Out wish Man Nippon Insulator Co., Ltd.
Claims (1)
て得た成形体を、２０００℃以上の非酸化雰囲気で焼成
した後、１０００℃以上１５００℃以下の酸化雰囲気で
熱処理することを特徴とする炭化珪素焼結体の製造法。1. A molded body obtained by molding a silicon carbide raw material having a silicon carbide content of 95% or more is fired in a non-oxidizing atmosphere at 2000°C or higher, and then heat-treated in an oxidizing atmosphere at 1000°C or higher and 1500°C or lower. Method for manufacturing silicon carbide sintered body.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63232263A JPH0283260A (en) | 1988-09-19 | 1988-09-19 | Production of sintered silicon carbide |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63232263A JPH0283260A (en) | 1988-09-19 | 1988-09-19 | Production of sintered silicon carbide |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0283260A true JPH0283260A (en) | 1990-03-23 |
Family
ID=16936513
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63232263A Pending JPH0283260A (en) | 1988-09-19 | 1988-09-19 | Production of sintered silicon carbide |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0283260A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2015171985A (en) * | 2014-02-19 | 2015-10-01 | 日本碍子株式会社 | Composite refractory and production method thereof |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6278177A (en) * | 1985-09-30 | 1987-04-10 | イビデン株式会社 | Strength recovery for silicon carbide sintered body processed article |
| JPS62148371A (en) * | 1985-12-23 | 1987-07-02 | 工業技術院長 | Manufacture of high strength silicon nitride-silicon carbidebase composite sintered body |
| JPS6360161A (en) * | 1986-09-01 | 1988-03-16 | イビデン株式会社 | Manufacture of high strength cubic silicon carbide sintered body |
-
1988
- 1988-09-19 JP JP63232263A patent/JPH0283260A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6278177A (en) * | 1985-09-30 | 1987-04-10 | イビデン株式会社 | Strength recovery for silicon carbide sintered body processed article |
| JPS62148371A (en) * | 1985-12-23 | 1987-07-02 | 工業技術院長 | Manufacture of high strength silicon nitride-silicon carbidebase composite sintered body |
| JPS6360161A (en) * | 1986-09-01 | 1988-03-16 | イビデン株式会社 | Manufacture of high strength cubic silicon carbide sintered body |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2015171985A (en) * | 2014-02-19 | 2015-10-01 | 日本碍子株式会社 | Composite refractory and production method thereof |
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