JPH0333088A - Porous sintered silicon carbide body and production thereof - Google Patents
Porous sintered silicon carbide body and production thereofInfo
- Publication number
- JPH0333088A JPH0333088A JP1165269A JP16526989A JPH0333088A JP H0333088 A JPH0333088 A JP H0333088A JP 1165269 A JP1165269 A JP 1165269A JP 16526989 A JP16526989 A JP 16526989A JP H0333088 A JPH0333088 A JP H0333088A
- Authority
- JP
- Japan
- Prior art keywords
- silicon carbide
- porous sintered
- oxide film
- forming material
- carbide 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.)
- Granted
Links
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 title claims abstract description 43
- 229910010271 silicon carbide Inorganic materials 0.000 title claims abstract description 41
- 238000004519 manufacturing process Methods 0.000 title claims description 7
- 239000000463 material Substances 0.000 claims abstract description 38
- 239000011148 porous material Substances 0.000 claims abstract description 26
- BNGXYYYYKUGPPF-UHFFFAOYSA-M (3-methylphenyl)methyl-triphenylphosphanium;chloride Chemical compound [Cl-].CC1=CC=CC(C[P+](C=2C=CC=CC=2)(C=2C=CC=CC=2)C=2C=CC=CC=2)=C1 BNGXYYYYKUGPPF-UHFFFAOYSA-M 0.000 claims abstract description 17
- 238000010304 firing Methods 0.000 claims description 10
- 230000003647 oxidation Effects 0.000 abstract description 14
- 238000007254 oxidation reaction Methods 0.000 abstract description 14
- 239000011248 coating agent Substances 0.000 abstract description 2
- 238000000576 coating method Methods 0.000 abstract description 2
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 abstract 3
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 abstract 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 abstract 2
- 229910052791 calcium Inorganic materials 0.000 abstract 2
- 239000011575 calcium Substances 0.000 abstract 2
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 abstract 1
- 239000002253 acid Substances 0.000 abstract 1
- 238000001354 calcination Methods 0.000 abstract 1
- BVKZGUZCCUSVTD-UHFFFAOYSA-N carbonic acid Chemical compound OC(O)=O BVKZGUZCCUSVTD-UHFFFAOYSA-N 0.000 abstract 1
- 230000006866 deterioration Effects 0.000 abstract 1
- -1 however Substances 0.000 abstract 1
- 229910052749 magnesium Inorganic materials 0.000 abstract 1
- 239000011777 magnesium Substances 0.000 abstract 1
- 150000003839 salts Chemical class 0.000 abstract 1
- 229910052720 vanadium Inorganic materials 0.000 abstract 1
- LEONUFNNVUYDNQ-UHFFFAOYSA-N vanadium atom Chemical compound [V] LEONUFNNVUYDNQ-UHFFFAOYSA-N 0.000 abstract 1
- 238000000034 method Methods 0.000 description 12
- 239000012298 atmosphere Substances 0.000 description 8
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 6
- 230000001590 oxidative effect Effects 0.000 description 6
- 239000000725 suspension Substances 0.000 description 6
- UXVMQQNJUSDDNG-UHFFFAOYSA-L Calcium chloride Chemical compound [Cl-].[Cl-].[Ca+2] UXVMQQNJUSDDNG-UHFFFAOYSA-L 0.000 description 5
- 239000001110 calcium chloride Substances 0.000 description 5
- 229910001628 calcium chloride Inorganic materials 0.000 description 5
- 150000001875 compounds Chemical class 0.000 description 5
- 239000011521 glass Substances 0.000 description 5
- 239000000243 solution Substances 0.000 description 5
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 4
- 239000001301 oxygen Substances 0.000 description 4
- 229910052760 oxygen Inorganic materials 0.000 description 4
- 239000007864 aqueous solution Substances 0.000 description 3
- 239000013078 crystal Substances 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 239000000843 powder Substances 0.000 description 3
- 229910052814 silicon oxide Inorganic materials 0.000 description 3
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 2
- TWRXJAOTZQYOKJ-UHFFFAOYSA-L Magnesium chloride Chemical compound [Mg+2].[Cl-].[Cl-] TWRXJAOTZQYOKJ-UHFFFAOYSA-L 0.000 description 2
- CSNNHWWHGAXBCP-UHFFFAOYSA-L Magnesium sulfate Chemical compound [Mg+2].[O-][S+2]([O-])([O-])[O-] CSNNHWWHGAXBCP-UHFFFAOYSA-L 0.000 description 2
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 description 2
- WNROFYMDJYEPJX-UHFFFAOYSA-K aluminium hydroxide Chemical compound [OH-].[OH-].[OH-].[Al+3] WNROFYMDJYEPJX-UHFFFAOYSA-K 0.000 description 2
- ILRRQNADMUWWFW-UHFFFAOYSA-K aluminium phosphate Chemical compound O1[Al]2OP1(=O)O2 ILRRQNADMUWWFW-UHFFFAOYSA-K 0.000 description 2
- VSGNNIFQASZAOI-UHFFFAOYSA-L calcium acetate Chemical compound [Ca+2].CC([O-])=O.CC([O-])=O VSGNNIFQASZAOI-UHFFFAOYSA-L 0.000 description 2
- 239000001639 calcium acetate Substances 0.000 description 2
- 229960005147 calcium acetate Drugs 0.000 description 2
- 235000011092 calcium acetate Nutrition 0.000 description 2
- 229940043430 calcium compound Drugs 0.000 description 2
- 150000001674 calcium compounds Chemical class 0.000 description 2
- OSGAYBCDTDRGGQ-UHFFFAOYSA-L calcium sulfate Chemical compound [Ca+2].[O-]S([O-])(=O)=O OSGAYBCDTDRGGQ-UHFFFAOYSA-L 0.000 description 2
- 238000005266 casting Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000000499 gel Substances 0.000 description 2
- 230000005484 gravity Effects 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 229910021426 porous silicon Inorganic materials 0.000 description 2
- 229910052710 silicon Inorganic materials 0.000 description 2
- 239000010703 silicon Substances 0.000 description 2
- 239000002002 slurry Substances 0.000 description 2
- 238000009489 vacuum treatment Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 229910021550 Vanadium Chloride Inorganic materials 0.000 description 1
- XHCLAFWTIXFWPH-UHFFFAOYSA-N [O-2].[O-2].[O-2].[O-2].[O-2].[V+5].[V+5] Chemical compound [O-2].[O-2].[O-2].[O-2].[O-2].[V+5].[V+5] XHCLAFWTIXFWPH-UHFFFAOYSA-N 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 239000012300 argon atmosphere Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 229910000019 calcium carbonate Inorganic materials 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000011362 coarse particle Substances 0.000 description 1
- 239000008119 colloidal silica Substances 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 238000011049 filling Methods 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 238000005470 impregnation Methods 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- UEGPKNKPLBYCNK-UHFFFAOYSA-L magnesium acetate Chemical compound [Mg+2].CC([O-])=O.CC([O-])=O UEGPKNKPLBYCNK-UHFFFAOYSA-L 0.000 description 1
- 239000011654 magnesium acetate Substances 0.000 description 1
- 235000011285 magnesium acetate Nutrition 0.000 description 1
- 229940069446 magnesium acetate Drugs 0.000 description 1
- ZLNQQNXFFQJAID-UHFFFAOYSA-L magnesium carbonate Chemical compound [Mg+2].[O-]C([O-])=O ZLNQQNXFFQJAID-UHFFFAOYSA-L 0.000 description 1
- 239000001095 magnesium carbonate Substances 0.000 description 1
- 229910000021 magnesium carbonate Inorganic materials 0.000 description 1
- 229910001629 magnesium chloride Inorganic materials 0.000 description 1
- 239000000395 magnesium oxide Substances 0.000 description 1
- CPLXHLVBOLITMK-UHFFFAOYSA-N magnesium oxide Inorganic materials [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 1
- 229910052943 magnesium sulfate Inorganic materials 0.000 description 1
- 235000019341 magnesium sulphate Nutrition 0.000 description 1
- AXZKOIWUVFPNLO-UHFFFAOYSA-N magnesium;oxygen(2-) Chemical compound [O-2].[Mg+2] AXZKOIWUVFPNLO-UHFFFAOYSA-N 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- RBFRVUKIVGOWND-UHFFFAOYSA-L oxygen(2-);vanadium(4+);sulfate Chemical compound [O-2].[V+4].[O-]S([O-])(=O)=O RBFRVUKIVGOWND-UHFFFAOYSA-L 0.000 description 1
- RPESBQCJGHJMTK-UHFFFAOYSA-I pentachlorovanadium Chemical compound [Cl-].[Cl-].[Cl-].[Cl-].[Cl-].[V+5] RPESBQCJGHJMTK-UHFFFAOYSA-I 0.000 description 1
- 239000011505 plaster Substances 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 230000035939 shock Effects 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- VXYADVIJALMOEQ-UHFFFAOYSA-K tris(lactato)aluminium Chemical compound CC(O)C(=O)O[Al](OC(=O)C(C)O)OC(=O)C(C)O VXYADVIJALMOEQ-UHFFFAOYSA-K 0.000 description 1
- 229910001935 vanadium oxide Inorganic materials 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、耐酸化性に優れた高温用構造部材に適した炭
化珪素多孔質焼結体及びその製造方法に関するもである
。DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a porous sintered body of silicon carbide suitable for high-temperature structural members having excellent oxidation resistance, and a method for producing the same.
（従来の技術及びその問題点〉
現在、純度９５％以上の高純度炭化珪素等の焼結体は高
温での強度、耐熱衝撃性等の特性を利用して、高温用構
造部材としての応用分野に使用されつつある。しかしな
がら、かかる構造部材を高温の酸化雰囲気中で使用する
場合、高純度炭化珪素焼結体中の結晶は酸素と反応し、
ＳｉＣ＋３／２０□→Ｓｉ口２＋ＣＤ
の反応式によって酸化珪素に変化する。この際焼結体内
に容積膨張が発生し、焼結体に強度低下を惹起する。従
って、高純度炭化珪素焼結体においては、耐酸化性を向
上させることが極めて重要なことである。(Prior art and its problems) Currently, sintered bodies such as high-purity silicon carbide with a purity of 95% or more are used in the field of application as structural members for high temperatures, taking advantage of their properties such as strength and thermal shock resistance at high temperatures. However, when such structural members are used in a high-temperature oxidizing atmosphere, the crystals in the high-purity silicon carbide sintered body react with oxygen, and the reaction formula is SiC+3/20□→Si2+CD. It changes to silicon oxide.At this time, volumetric expansion occurs within the sintered body, causing a decrease in the strength of the sintered body.Therefore, it is extremely important to improve the oxidation resistance of high-purity silicon carbide sintered bodies. That's true.
また、再結晶炭化珪素多孔体の開気孔中に金属シリコン
等を含浸させることが知られている（特開昭４８−３７
４０４、同５７−４３５５３号、同５７−４５７０８号
公報〉これは、焼結体の開気孔中に珪素を圧入すること
により、耐酸化性に優れた高強度の緻密な高温用構造部
材を得ようとするものである。しかし、含浸のための設
備、処理費用が高価である。It is also known to impregnate metal silicon etc. into the open pores of a recrystallized silicon carbide porous body (Japanese Patent Laid-Open No. 48-37
404, No. 57-43553, No. 57-45708 This method obtains a high-strength, dense high-temperature structural member with excellent oxidation resistance by press-fitting silicon into the open pores of a sintered body. This is what we are trying to do. However, equipment and processing costs for impregnation are expensive.
また、再結晶炭化珪素多孔体に炭化珪素等の耐酸化材を
コーティングすることが知られている。Furthermore, it is known to coat a recrystallized silicon carbide porous body with an oxidation-resistant material such as silicon carbide.
しかし、この方法では、焼結多孔体からコーテイング材
が剥離する。However, in this method, the coating material peels off from the sintered porous body.
更に、再結晶炭化珪素多孔体の開気孔中に、アルミナ、
シリカ、ジルコニア等の微粉末を充填し、耐酸化性の向
上を図る技術が知られている（特開昭６３−２８６８号
公報）。しかし、製品の肉厚が大きくなると、粉末の充
填を均一に行えず、組織が不均一になる。このため、高
温の酸化雰囲気で使用する場合酸化速度が場所によって
違ってくるので、内部にマイクロクラブクが発生して強
度が低下する。Furthermore, alumina,
A technique is known in which the oxidation resistance is improved by filling fine powder of silica, zirconia, etc. (Japanese Unexamined Patent Publication No. 63-2868). However, when the wall thickness of the product increases, the powder cannot be filled uniformly, resulting in uneven structure. For this reason, when used in a high-temperature oxidizing atmosphere, the oxidation rate varies depending on the location, causing microcracks to occur inside and reducing strength.
（発明が解決しようとする課題〉
本発明の課題は、炭化珪素多孔質焼結体の少なくとも開
気孔の表面に酸化物被膜形成材を均一に付着させ、焼結
体の耐酸化性を高めることができ、酸化雰囲気中、高温
で使用しても強度低下が生じない、炭化珪素多孔質焼結
体及びその製造方法を提供することである。(Problems to be Solved by the Invention) An object of the present invention is to uniformly adhere an oxide film forming material to at least the surface of open pores of a porous sintered silicon carbide body, thereby increasing the oxidation resistance of the sintered body. It is an object of the present invention to provide a porous sintered body of silicon carbide which can be used in an oxidizing atmosphere and at high temperatures without causing a decrease in strength, and a method for manufacturing the same.
（課題を解決するための手段）
本発明は、炭化珪素多孔質焼結体の少なくとも開気孔の
表面が、少なくとも硝酸アルミニウムを含む酸化物被膜
形成材を焼成してなる酸化物被膜により覆われている、
炭化珪素多孔質焼結体に係るものである。(Means for Solving the Problems) The present invention provides that at least the surface of open pores of a porous sintered silicon carbide body is covered with an oxide film formed by firing an oxide film forming material containing at least aluminum nitrate. There is,
This relates to a porous sintered silicon carbide body.
また、本発明は、高純度炭化珪素を焼成して炭化珪素多
孔質焼結体を形成する工程と；この炭化珪素多孔質焼結
体の少なくとも開気孔の表面に、少なくとも硝酸アルミ
ニウムを含む酸化物被膜形成材を付着させる工程と；
しかる後に前記炭化珪素多孔質焼結体を焼成し、少なく
とも前記開気孔の表面に酸化物被膜を形成する工程と
を有する炭化珪素多孔質焼結体の製造方法に係るもであ
る。The present invention also provides a step of firing high-purity silicon carbide to form a silicon carbide porous sintered body; A method for producing a porous sintered silicon carbide body, comprising: attaching a film-forming material; and then firing the porous sintered silicon carbide body to form an oxide film on at least the surface of the open pores. This is related to.
ここで、炭化珪素多孔質焼結体は、鋳込み法、押し出し
法、プレス法等、公知の方法で筒状体、板状体等を姶め
、種々の形状に底形できる。Here, the silicon carbide porous sintered body can be shaped into various bottom shapes, such as a cylindrical body, a plate-shaped body, etc., by a known method such as a casting method, an extrusion method, or a pressing method.
炭化珪素多孔質焼結体の開気孔率は、５〜２０％が好ま
しい。５％未満では、開気孔中に充分な量の酸化物被膜
形成材を付着させることができず、２０％を超えると、
焼結体自体の強度が低下し、構造部材としての使用に耐
えない。The open porosity of the porous sintered silicon carbide body is preferably 5 to 20%. If it is less than 5%, a sufficient amount of oxide film forming material cannot be deposited in the open pores, and if it exceeds 20%,
The strength of the sintered body itself decreases, making it unusable as a structural member.
少なくとも硝酸アルミニウムを含有する酸化物被膜形成
材には、他の化合物をも含有させてよい。The oxide film forming material containing at least aluminum nitrate may also contain other compounds.
こうした化合物としては、カルシウム化合物（塩化カル
シウム、酢酸カルシウム、硫酸カルシウム、炭酸カルシ
ウム〉が好ましい。また、他には、硫酸マグネシウム、
塩化マグネシウム、酢酸マグネシウム、炭酸マグネシウ
ム、酸化マグネシウム、酸化硫酸バナジウム、塩化バナ
ジウム、酸化バナジウム、コロイダルシリカ等を例示で
きる。酸化物被膜は、好ましくはガラス被膜とする。酸
化物被膜形成材の炭化珪素多孔質焼結体に対する付着量
は、焼結体全体に対して酸化物換算で０．１〜０．６重
量％とするのが好ましい。また、硝酸アルミニウムとカ
ルシウム化合物とを併用する場合には、両者の混合比は
重量比で３：２〜２：３とするのが好ましい。形成材の
付着量が０．１重量％未渦の場合には、酸化物被膜が炭
化珪素の開気孔の表面を完全に被膜するには十分とはい
えず、０．６重量％を越える場合には、酸化物被膜の量
が多すぎ、高温での使用時に酸化物被膜形成材が構造部
材の表面に融出するおそれがある。As such compounds, calcium compounds (calcium chloride, calcium acetate, calcium sulfate, calcium carbonate) are preferable.Other examples include magnesium sulfate,
Examples include magnesium chloride, magnesium acetate, magnesium carbonate, magnesium oxide, vanadium oxide sulfate, vanadium chloride, vanadium oxide, and colloidal silica. The oxide film is preferably a glass film. The amount of the oxide film forming material attached to the porous silicon carbide sintered body is preferably 0.1 to 0.6% by weight in terms of oxide based on the entire sintered body. Further, when aluminum nitrate and a calcium compound are used together, the mixing ratio of both is preferably 3:2 to 2:3 by weight. If the amount of the forming material deposited is 0.1% by weight without swirling, it is not sufficient for the oxide film to completely cover the surface of the open pores of silicon carbide, and if it exceeds 0.6% by weight. The amount of the oxide film is too large, and there is a risk that the oxide film forming material may melt onto the surface of the structural member when used at high temperatures.
酸化物被膜形成材を、少なくとも開気孔中に付着させる
には、以下の方法を採りうる。酸化物被膜形成材として
は、上記した種々の化合物を単独または組合せて用いる
が、これらの化合物が水その他の溶媒に可溶性である場
合には溶液として用い、難溶性である場合には懸濁液と
して用いる。The following method can be used to deposit the oxide film forming material at least into the open pores. As the oxide film forming material, the various compounds mentioned above are used alone or in combination. If these compounds are soluble in water or other solvents, they are used as a solution, and if they are poorly soluble, they are used as a suspension. used as
この場合には化合物を１μｍ以下、０．５μｍ前後の超
微粉末として用いることが好ましい。In this case, it is preferable to use the compound as an ultrafine powder of 1 μm or less and around 0.5 μm.
これらの溶液又は懸濁液を、開気孔中に圧太し、乾燥さ
せることが好ましい。圧入子役としては、焼結体および
同形成材の溶液または懸濁液を同一の容器に入れ、この
容器を高度に減圧することにより、溶液または懸濁液は
焼結体の開気孔中に容易に圧入される。また、加圧法に
よっても同様に圧入を行なえる。Preferably, these solutions or suspensions are compressed into open pores and dried. For press-fitting, the solution or suspension of the sintered body and the same forming material are placed in the same container, and by highly reducing the pressure in this container, the solution or suspension is easily poured into the open pores of the sintered body. is press-fitted into the Further, press-fitting can be similarly performed by a pressurizing method.
上記溶液・懸濁液の粘度は、０，５〜３．０ポイズとす
ることが好ましい。これが０．５ポイズ未満の場合には
、圧入後形成材がゲル化するまでに重力による移動が発
生し、形成材の分布に斑を生じ、粘度が３．０ポイズを
越える場合には、形成材の粘度が高く、焼結体の開気孔
中に十分には浸入しない。The viscosity of the solution/suspension is preferably 0.5 to 3.0 poise. If this is less than 0.5 poise, movement due to gravity will occur before the forming material gels after press-fitting, causing uneven distribution of the forming material, and if the viscosity exceeds 3.0 poise, the forming material will move due to gravity until it gels. The material has a high viscosity and does not fully penetrate into the open pores of the sintered body.
こうして開気孔に酸化物被膜形成材を付着させた後、炭
化珪素焼結多孔体の焼成を行う。この焼成は１２００〜
１５００℃の温度、酸素濃度２％以上の酸化雰囲気中で
行うことが好ましい。焼成温度が１２００℃未満の場合
には、酸化物被膜が十分には形成されないおそれがあり
、焼成温度が１５００℃を越えると、焼結体からの酸化
珪素の生成が多くなり、酸化物被膜の融出の原因になる
とともに、寿命を短くする。また、雰囲気中の酸素濃度
に関しては、２％未満の場合には、焼結体からの酸化珪
素の生成がなく、酸化物被膜が形成されにくくなる。After the oxide film forming material is deposited in the open pores in this manner, the sintered porous silicon carbide body is fired. This firing is from 1200~
It is preferable to carry out the process at a temperature of 1500° C. in an oxidizing atmosphere with an oxygen concentration of 2% or more. If the firing temperature is less than 1200°C, there is a risk that the oxide film will not be formed sufficiently, and if the firing temperature exceeds 1500°C, more silicon oxide will be produced from the sintered body, leading to the formation of the oxide film. It causes melting and shortens the lifespan. Regarding the oxygen concentration in the atmosphere, if it is less than 2%, no silicon oxide is produced from the sintered body, and an oxide film is difficult to form.
酸化被膜形成材を乾燥に先立ちゲル化することもできる
。これには、所定の温度で所定時間例えば１０時間静置
するか、形成材のｐＨを所定の値例えばｐＨ６以上に調
整する。The oxide film forming material can also be gelled prior to drying. For this purpose, either the material is allowed to stand at a predetermined temperature for a predetermined period of time, for example, 10 hours, or the pH of the forming material is adjusted to a predetermined value, for example, pH 6 or higher.
（発明の作用効果）
本発明に係る炭化珪素多孔質焼結体によれば、開気孔に
露出する炭化珪素の結晶の表面に酸化物被膜を形成して
いるので、高温の酸化雰囲気中でも上記結晶と酸素とが
遮断され、炭化珪素の酸化が防止される。(Operations and Effects of the Invention) According to the porous sintered body of silicon carbide according to the present invention, since an oxide film is formed on the surface of the silicon carbide crystals exposed to the open pores, the above-mentioned crystals can be used even in a high-temperature oxidizing atmosphere. and oxygen are blocked, and oxidation of silicon carbide is prevented.
しかも、酸化物被膜形成材に硝酸アルミニウムという特
定の物質を含有させたことが重要である。Moreover, it is important that the oxide film forming material contains a specific substance called aluminum nitrate.
発明者は、耐酸化性を高めるべく、実験を積み重ねるこ
とにより、初めて硝酸アルミニウムの特異な作用効果に
到達したのである。即ち、開気孔中に、例えば水酸化ア
ルミニウム、燐酸アルミニウム、乳酸アルミニウム等か
らなる酸化物被膜形成材を付着させても、この付着工程
において、酸化物被膜形成材が開気孔表面に不均一に付
着してしまい、未だ耐酸化性に改善の余地があることが
、本発明者の検討により明らかにされたのである。The inventor first arrived at the unique effects of aluminum nitrate through repeated experiments in order to improve its oxidation resistance. That is, even if an oxide film-forming material made of, for example, aluminum hydroxide, aluminum phosphate, aluminum lactate, etc. is deposited into the open pores, the oxide film-forming material will adhere unevenly to the surface of the open pores during this adhesion process. The inventor's studies have revealed that there is still room for improvement in oxidation resistance.
一方、硝酸アルミニウムはノックス除去の必要があるの
で、本来は好適な材料とは考えにくいものである。とこ
ろが、硝酸アルミニウムを酸化物被膜形成材として使用
すると、開気孔表面に極めて均一に付着し、高温、酸化
雰囲気下で長時間使用しても、マイクロクラブクが抑え
られ、強度低下を防止できたのである。このように、硝
酸アルミニウムが予想外にも最適の材料であることが本
発明者によって発見されたのである。On the other hand, since aluminum nitrate requires removal of nox, it is difficult to think of it as a suitable material. However, when aluminum nitrate was used as an oxide film-forming material, it adhered extremely uniformly to the open pore surface, suppressing microcracks and preventing strength loss even when used for long periods at high temperatures and in an oxidizing atmosphere. It is. Thus, it has been unexpectedly discovered by the inventors that aluminum nitrate is the most suitable material.
多孔質の焼結体であるので、焼成時に収縮せず、寸法精
度を高くでき、大型、複雑な形状の成形品を製作できる
。従って、上記した耐酸化性の向上により、極めて有用
な高温用構造部材として本発明に係る炭化珪素多孔質焼
結体を提供できる。Since it is a porous sintered body, it does not shrink during firing, allowing for high dimensional accuracy and the production of large, complex-shaped molded products. Therefore, due to the above-described improvement in oxidation resistance, the porous sintered body of silicon carbide according to the present invention can be provided as an extremely useful high-temperature structural member.
また、本発明に係る炭化珪素多孔質焼結体の製造方法に
よれば、少なくとも上記開気孔の表面に、少なくとも硝
酸アルミニウムを含む酸化物被膜形成材を付着させ、し
かる後に焼成しているので、本発明に係る焼結体を好適
に製造できる。Further, according to the method for producing a porous sintered silicon carbide body according to the present invention, an oxide film forming material containing at least aluminum nitrate is attached to at least the surface of the open pores, and then fired. The sintered body according to the present invention can be suitably manufactured.
（実施例〉 以下、具体的な実施例について説明する。(Example> Hereinafter, specific examples will be described.
実施例１
炭化珪素の粗粒（平均粒径２１０μｍ〉 と微粒（平均
粒径０．６μｍ）とを１：１の割合で配合し水を１５重
量％添加し、これをポットミルで混合してスラリーを作
製した。このスラリーを石膏型へ鋳込んで作った成形体
をアルゴン雰囲気中、２３００℃の温度で焼成し、平板
状の再結晶炭化珪素多孔質焼結体を得た。Example 1 Coarse particles (average particle size 210 μm) and fine particles (average particle size 0.6 μm) of silicon carbide were blended in a 1:1 ratio, 15% by weight of water was added, and this was mixed in a pot mill to form a slurry. A molded body made by casting this slurry into a plaster mold was fired at a temperature of 2300°C in an argon atmosphere to obtain a flat recrystallized silicon carbide porous sintered body.
また、下記表に示す各種ガラス被膜形成材が下記表に示
す各種濃度で含有されている水溶液を調製した。この水
溶液を、真空処理法によって上記焼結体の開気孔中に圧
入、含浸させた。次いで、これを乾燥し、ガラス被膜形
成材を開気孔の表面に付着させた。同焼結体を空気中１
３００℃の温度で再焼成した。得られた焼結体の特性を
第１表に示す。なお、第１表における％は重量％で、圧
入量は酸化物換算による重量％であり、また耐酸化性値
は試料を大気中１３００℃で１０００〜２０００時間曝
露した時の１時間当たりの重量増加率（ｐｐｍ／ｈ）を
示す。In addition, aqueous solutions containing various glass film forming materials shown in the table below at various concentrations shown in the table below were prepared. This aqueous solution was press-fitted into the open pores of the sintered body and impregnated therein by a vacuum treatment method. Next, this was dried, and a glass film forming material was attached to the surface of the open pores. The same sintered body was placed in the air.
Refired at a temperature of 300°C. Table 1 shows the properties of the obtained sintered body. In addition, % in Table 1 is weight %, the injection amount is weight % in terms of oxide, and the oxidation resistance value is the weight per hour when the sample is exposed to the atmosphere at 1300°C for 1000 to 2000 hours. The increase rate (ppm/h) is shown.
表
Ｂ：硝酸アルミニウム：酢酸カルシウム＝１：１（重量
比〉ａ：水酸化アルミニウム：塩化カルシウム＝１：１
（重量比）ｂ：燐酸アルミニウム：塩化カルシウム＝１
：１（重量比）実施例２
塩化カルシウムと硝酸アルミニウムとの各種配合（重量
〉の５重量％懸濁液（酸化物換算）をガラス被膜形成材
として用いた点を除き、実施例１と同様にして得た再結
晶炭化珪素多孔質焼結体の特性を表２に示す。なお、耐
酸化性の試験も実施例１と同様である。但し、ｒＡ １
２０ｓ／ＣａＯ」は酸化物換算の重量比を示す。Table B: Aluminum nitrate: Calcium acetate = 1:1 (weight ratio> a: Aluminum hydroxide: Calcium chloride = 1:1
(Weight ratio) b: aluminum phosphate: calcium chloride = 1
:1 (weight ratio) Example 2 Same as Example 1 except that a 5% by weight suspension (in terms of oxide) of various combinations (by weight) of calcium chloride and aluminum nitrate was used as the glass film forming material. Table 2 shows the properties of the recrystallized silicon carbide porous sintered body obtained in Example 1.The oxidation resistance test was also the same as in Example 1.However, rA 1
20s/CaO" indicates the weight ratio in terms of oxide.
表２
実施例１で得た未圧入の焼結体の開気孔中に、ガラス被
膜形成材である硝酸アルミニウムと塩化カルシウムとの
１＝１配合の７．５重量％水溶液を真空処理法にて圧入
して乾燥後、各種の条件で再焼成した。得られた高温用
構造部材の実施例１゜２に対応する特性を表３に示す。Table 2 A 7.5% aqueous solution of aluminum nitrate and calcium chloride, which are glass film forming materials, in a 1=1 ratio was added into the open pores of the unpressurized sintered body obtained in Example 1 using a vacuum treatment method. After being press-fitted and dried, it was fired again under various conditions. Table 3 shows the properties of the obtained high-temperature structural member corresponding to Example 1.2.
なお、焼結体への形成材の圧入量は酸化物換算で０．４
重量％である。The amount of material injected into the sintered body is 0.4 in terms of oxide.
Weight%.
表３Table 3
Claims (2)
、少なくとも硝酸アルミニウムを含有する酸化物被膜形
成材を焼成してなる酸化物被膜により覆われている炭化
珪素多孔質焼結体。1. A porous sintered silicon carbide body, wherein at least the surfaces of open pores of the porous sintered body are covered with an oxide film formed by firing an oxide film forming material containing at least aluminum nitrate.
形成する工程と； この炭化珪素多孔質焼結体の少なくとも開 気孔の表面に、少なくとも硝酸アルミニウムを含む酸化
物被膜形成材を付着させる工程と；しかる後に前記炭化
珪素多孔質焼結体を焼 成し、少なくとも前記開気孔の表面に酸化物被膜を形成
する工程と を有する炭化珪素多孔質焼結体の製造方法。2. a step of firing high-purity silicon carbide to form a porous sintered silicon carbide body; attaching an oxide film-forming material containing at least aluminum nitrate to at least the surface of open pores of the porous sintered body of silicon carbide; A method for producing a porous sintered body of silicon carbide, comprising the steps of: thereafter firing the porous sintered body of silicon carbide to form an oxide film on at least the surface of the open pores.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1165269A JP2588276B2 (en) | 1989-06-29 | 1989-06-29 | Silicon carbide porous sintered body and method for producing the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1165269A JP2588276B2 (en) | 1989-06-29 | 1989-06-29 | Silicon carbide porous sintered body and method for producing the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0333088A true JPH0333088A (en) | 1991-02-13 |
| JP2588276B2 JP2588276B2 (en) | 1997-03-05 |
Family
ID=15809124
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1165269A Expired - Fee Related JP2588276B2 (en) | 1989-06-29 | 1989-06-29 | Silicon carbide porous sintered body and method for producing the same |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2588276B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20000006202A (en) * | 1998-06-23 | 2000-01-25 | 시바타 마사하루 | A highly resistive recrystallized silicon carbide, an anti-corrosive member, a method for producing the highly resistive recrystallized silicon carbide, and a method for producing the anti-corrosive member |
| JP2001181047A (en) * | 1999-12-22 | 2001-07-03 | Tokai Konetsu Kogyo Co Ltd | Silicon carbide heating element |
| JP2019014636A (en) * | 2017-07-10 | 2019-01-31 | 三井金属鉱業株式会社 | Silicon carbide sintered substrate and electronic component sintering jig provided with the same |
-
1989
- 1989-06-29 JP JP1165269A patent/JP2588276B2/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20000006202A (en) * | 1998-06-23 | 2000-01-25 | 시바타 마사하루 | A highly resistive recrystallized silicon carbide, an anti-corrosive member, a method for producing the highly resistive recrystallized silicon carbide, and a method for producing the anti-corrosive member |
| JP2001181047A (en) * | 1999-12-22 | 2001-07-03 | Tokai Konetsu Kogyo Co Ltd | Silicon carbide heating element |
| JP2019014636A (en) * | 2017-07-10 | 2019-01-31 | 三井金属鉱業株式会社 | Silicon carbide sintered substrate and electronic component sintering jig provided with the same |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2588276B2 (en) | 1997-03-05 |
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