JP2543408B2 - Ceramic heat insulating member and manufacturing method thereof - Google Patents
Ceramic heat insulating member and manufacturing method thereofInfo
- Publication number
- JP2543408B2 JP2543408B2 JP1151236A JP15123689A JP2543408B2 JP 2543408 B2 JP2543408 B2 JP 2543408B2 JP 1151236 A JP1151236 A JP 1151236A JP 15123689 A JP15123689 A JP 15123689A JP 2543408 B2 JP2543408 B2 JP 2543408B2
- Authority
- JP
- Japan
- Prior art keywords
- zirconia
- heat insulating
- insulating member
- substrate
- temperature
- 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.)
- Expired - Lifetime
Links
- 239000000919 ceramic Substances 0.000 title claims description 17
- 238000004519 manufacturing process Methods 0.000 title claims description 7
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 claims description 40
- 239000000758 substrate Substances 0.000 claims description 17
- CPLXHLVBOLITMK-UHFFFAOYSA-N Magnesium oxide Chemical compound [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 claims description 16
- 239000000843 powder Substances 0.000 claims description 10
- 229910052582 BN Inorganic materials 0.000 claims description 9
- PZNSFCLAULLKQX-UHFFFAOYSA-N Boron nitride Chemical compound N#B PZNSFCLAULLKQX-UHFFFAOYSA-N 0.000 claims description 9
- 229910052581 Si3N4 Inorganic materials 0.000 claims description 9
- 239000000395 magnesium oxide Substances 0.000 claims description 8
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical group N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 claims description 7
- 238000005245 sintering Methods 0.000 claims description 7
- 238000007789 sealing Methods 0.000 claims description 6
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 claims description 6
- 229910010271 silicon carbide Inorganic materials 0.000 claims description 6
- RKTYLMNFRDHKIL-UHFFFAOYSA-N copper;5,10,15,20-tetraphenylporphyrin-22,24-diide Chemical compound [Cu+2].C1=CC(C(=C2C=CC([N-]2)=C(C=2C=CC=CC=2)C=2C=CC(N=2)=C(C=2C=CC=CC=2)C2=CC=C3[N-]2)C=2C=CC=CC=2)=NC1=C3C1=CC=CC=C1 RKTYLMNFRDHKIL-UHFFFAOYSA-N 0.000 claims description 5
- 230000007704 transition Effects 0.000 claims description 5
- 238000000034 method Methods 0.000 claims description 4
- 239000000203 mixture Substances 0.000 claims description 4
- 239000013078 crystal Substances 0.000 claims description 3
- 238000000151 deposition Methods 0.000 claims description 3
- 238000001816 cooling Methods 0.000 claims description 2
- 238000010438 heat treatment Methods 0.000 claims description 2
- 239000003795 chemical substances by application Substances 0.000 claims 2
- 229910002077 partially stabilized zirconia Inorganic materials 0.000 claims 2
- 239000010987 cubic zirconia Substances 0.000 claims 1
- 239000002244 precipitate Substances 0.000 claims 1
- 230000000087 stabilizing effect Effects 0.000 claims 1
- 230000035882 stress Effects 0.000 description 6
- 239000011148 porous material Substances 0.000 description 5
- 230000000052 comparative effect Effects 0.000 description 4
- 239000011810 insulating material Substances 0.000 description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- 238000005452 bending Methods 0.000 description 2
- 238000009413 insulation Methods 0.000 description 2
- 238000007733 ion plating Methods 0.000 description 2
- VXEGSRKPIUDPQT-UHFFFAOYSA-N 4-[4-(4-methoxyphenyl)piperazin-1-yl]aniline Chemical compound C1=CC(OC)=CC=C1N1CCN(C=2C=CC(N)=CC=2)CC1 VXEGSRKPIUDPQT-UHFFFAOYSA-N 0.000 description 1
- 239000004372 Polyvinyl alcohol Substances 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 238000001354 calcination Methods 0.000 description 1
- 239000011247 coating layer Substances 0.000 description 1
- 230000006378 damage Effects 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000006355 external stress Effects 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 238000010304 firing Methods 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 239000010410 layer Substances 0.000 description 1
- 229920002451 polyvinyl alcohol Polymers 0.000 description 1
- 239000005049 silicon tetrachloride Substances 0.000 description 1
- 238000007582 slurry-cast process Methods 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
Description
【発明の詳細な説明】 （産業上の利用分野） 本発明は、セラミックスエンジン等の構造部材として
好適な高強度低熱伝導率のセラミックス製断熱部材及び
その製造方法に関する。Description: TECHNICAL FIELD The present invention relates to a high-strength and low-heat-conductivity ceramic heat insulating member suitable as a structural member for a ceramic engine and the like, and a method for manufacturing the same.
（従来の技術） 従来の構造部材として使用されるセラミックス製断熱
部材としてはジルコニアの焼結体が用いられている。ジ
ルコニアは熱伝導率が0.007cal/cm・sec・℃であるため
断熱性を有しており、また機械的強度にも優れている。(Prior Art) As a ceramic heat insulating member used as a conventional structural member, a zirconia sintered body is used. Since zirconia has a thermal conductivity of 0.007 cal / cm · sec · ° C, it has heat insulating properties and also has excellent mechanical strength.
一方、断熱材を多孔質状に形成し内部に気孔を多数含
有させることにより、該断熱材の熱伝導率が減少するこ
とが知られている。On the other hand, it is known that the thermal conductivity of the heat insulating material is reduced by forming the heat insulating material in a porous form and containing a large number of pores inside.
（発明が解決しようとする課題） このような従来のジルコニアからなる断熱部材を多孔
質化すると熱伝導率は減少するものの、機械的強度が低
下し構造部材として使用できなくなるという問題があ
る。また、多孔質化により部材の気密性が損なわれ、例
えばエンジンのシリンダのように気密性が要求される場
所には使用できないという問題がある。(Problems to be Solved by the Invention) If such a conventional heat insulating member made of zirconia is made porous, the thermal conductivity is reduced, but the mechanical strength is lowered and it cannot be used as a structural member. Further, there is a problem that the airtightness of the member is impaired due to the porosity, and the member cannot be used in a place where airtightness is required such as an engine cylinder.
本発明は、上記の点に鑑みてなされたもので、多孔質
状でありながら機械的強度が低下せず、かつ気密性に優
れたセラミックス製断熱部材及びその製造方法を提供し
ようとするものである。The present invention has been made in view of the above points, and is intended to provide a ceramic heat insulating member excellent in airtightness and a method of manufacturing the same, which is porous but does not deteriorate in mechanical strength. is there.
（課題を解決するための手段） ジルコニアにマグネシアと窒化硼素とを添加し焼結し
て断熱部材の基体を作成する。マグネシアを添加するこ
とによりジルコニアを部分安定化し、部材内部に正方晶
ジルコニアの微細結晶を分散させ基体の機械的強度、特
に破壊靭性を向上させる。また、窒化硼素を添加し焼結
時に基体内部に形成される気孔を微細化し均一に分散さ
せることにより強度の偏りを防止し応力の集中を解消し
て機械的強度を向上させる。更に部材表面の孔部をCVD
法あるいはイオンプレーティング法により形成される高
強度で高温安定性に優れたセラミックスである窒化珪素
あるいは炭化珪素により密封することにより部材の気密
性を向上させる。(Means for Solving the Problem) Magnesia and boron nitride are added to zirconia and sintered to form a substrate of a heat insulating member. By adding magnesia, zirconia is partially stabilized, and fine crystals of tetragonal zirconia are dispersed inside the member to improve the mechanical strength of the substrate, especially the fracture toughness. Further, by adding boron nitride and making the pores formed inside the substrate during sintering finer and uniformly dispersed, bias of strength is prevented, concentration of stress is eliminated, and mechanical strength is improved. Furthermore, the holes on the surface of the member are CVD
The airtightness of the member is improved by sealing with silicon nitride or silicon carbide, which is a ceramic having high strength and excellent in high-temperature stability formed by the method or the ion plating method.
（作用） 本発明のセラミックス製断熱部材及びその製造方法で
は、基体を構成するジルコニアがマグネシアにより部分
安定化されているので、外部からの応力が作用すると基
体内部に分散している正方晶ジルコニアが応力誘起変態
により単斜晶ジルコニアに相転移し、該相転移の際に外
部からの応力エネルギを吸収するため破壊靭性が向上す
る。また、該相転移は体積膨張を伴なうため基体内部に
圧縮応力を発生させ、破壊の原因となるクラックの成長
を有効に抑制する。一方、窒化硼素の添加により基体内
部の気孔が微細化し均一に分散するので応力の集中に偏
りが無く、よって機械的強度が向上する。更に、該基体
表面の孔部を高強度で高温安定性に優れたセラミックス
である窒化珪素あるいは炭化珪素により密封するので気
密性が向上する。(Operation) In the ceramic heat insulating member and the method for producing the same of the present invention, since the zirconia constituting the base is partially stabilized by magnesia, the tetragonal zirconia dispersed inside the base when external stress acts. The stress-induced transformation causes a phase transition to monoclinic zirconia, and during the phase transition, stress energy from the outside is absorbed, so that fracture toughness is improved. Further, since the phase transition accompanies volume expansion, compressive stress is generated inside the substrate, and the growth of cracks that cause destruction is effectively suppressed. On the other hand, the addition of boron nitride makes the pores inside the substrate finer and evenly dispersed, so that the stress concentration is not biased, and the mechanical strength is improved. Further, since the pores on the surface of the substrate are sealed with silicon nitride or silicon carbide, which is a ceramic having high strength and excellent stability at high temperature, airtightness is improved.
（実施例） 以下、本発明の実施例を詳細に説明する。(Example) Hereinafter, the Example of this invention is described in detail.
ジルコニア粉末とマグネシア粉末3wt％との混合粉末
をボールミルで粉砕混合分散後、焼結炉内にて加熱し12
00℃の状態で１時間保持し仮焼成を行なう。該仮焼成後
にボールミルにて粉砕し再び粉末状にする。そして、該
粉末に窒化硼素粉末10wt％を添加し再びボールミルにて
混合分散する。該分散後に、バインダとしてポリビニル
アルコール1wt％を加え混練した後、泥漿鋳込みを行な
い乾燥させ仮成型体を作製する。次に、該仮成型体を焼
結炉内に配置し、1700℃で２時間焼成した後、毎分10℃
の速度で1400℃まで冷却し、続いて毎分３℃の速度で11
00℃まで冷却する。そして、一旦室温まで炉冷した後、
再び加熱し1080℃の状態を８時間保持した後炉冷して多
孔質状の基体を作成する。Mix powder of zirconia powder and magnesia powder 3wt% with a ball mill, mix and disperse, and heat in a sintering furnace.
Temporary baking is performed by holding at 00 ° C for 1 hour. After the calcination, it is crushed by a ball mill and made into powder again. Then, 10 wt% of boron nitride powder is added to the powder, and the mixture is dispersed again in a ball mill. After the dispersion, 1 wt% of polyvinyl alcohol is added as a binder and kneaded, and then slurry casting is carried out and dried to prepare a temporary molded body. Next, after placing the temporary molded body in a sintering furnace and firing at 1700 ° C. for 2 hours, 10 ° C./min.
At a rate of 1400 ° C, and then at a rate of 3 ° C per minute 11
Cool to 00 ° C. And after furnace cooling to room temperature once,
After heating again and maintaining the temperature of 1080 ° C. for 8 hours, it is cooled in a furnace to form a porous substrate.
該基体をCVD反応炉内に配置し1050℃に加熱して四塩
化珪素とアンモニアのガスを3:4のモル比で該CVD反応炉
内に導入し10分間保持して基体表面に層厚10μｍの窒化
珪素からなるコーティング層を被着させることにより断
熱部材Ａを作成する。The substrate is placed in a CVD reaction furnace, heated to 1050 ° C., and a gas of silicon tetrachloride and ammonia is introduced into the CVD reaction furnace at a molar ratio of 3: 4 and held for 10 minutes to form a layer thickness of 10 μm on the surface of the substrate. The heat insulating member A is prepared by depositing the coating layer made of silicon nitride.
該断熱部材Ａとの比較のためジルコニア粉末のみを圧
縮整形した後焼結し、緻密な組織の比較部材Ｂを作成す
る。断熱部材Ａと比較部材Ｂとの熱伝導率及び曲げ強度
の比較結果を表１に示す。For comparison with the heat insulating member A, only zirconia powder is compression-shaped and then sintered to prepare a comparative member B having a dense structure. Table 1 shows the comparison results of the thermal conductivity and the bending strength of the heat insulating member A and the comparative member B.
表１に示すごとく、本願発明による断熱部材Ａの熱伝
導率は比較部材Ｂの熱伝導率に対して極めて小であり、
断熱性に優れている。また、曲げ強度は比較部材Ｂより
若干劣るものの600MPaであり構造部材として充分の強度
を有している。 As shown in Table 1, the heat conductivity of the heat insulating member A according to the present invention is extremely smaller than that of the comparative member B,
Has excellent heat insulation. The bending strength is 600 MPa, which is slightly inferior to that of the comparative member B, and is sufficient as a structural member.
そして、表面に被着したCVD−窒化珪素は緻密な組織
となっており気密性も充分に有している。The CVD-silicon nitride deposited on the surface has a dense structure and has sufficient airtightness.
尚、断熱部材ＡのCVD−窒化珪素被着前の表面を電子
顕微鏡で観察した結果、孔径平均0.5μｍの均一に分散
した微孔が観察され、断熱部材Ａ内に強度の偏りが発生
しないことが確認された。In addition, as a result of observing the surface of the heat insulating member A before the deposition of CVD-silicon nitride with an electron microscope, uniformly dispersed micropores having an average hole diameter of 0.5 μm are observed, and the unevenness of strength does not occur in the heat insulating member A. Was confirmed.
上記実施例においては窒化硼素の添加量を10％とした
が、断熱材の使用目的により要求される断熱性及び強度
に応じて変化させることは可能である。また、断熱部材
Ａの表面に窒化珪素を被着した実施例を示したが炭化珪
素を被着してもよい。In the above examples, the amount of boron nitride added was set to 10%, but it can be changed depending on the heat insulating property and strength required depending on the purpose of use of the heat insulating material. Further, although an example in which silicon nitride is deposited on the surface of the heat insulating member A has been shown, silicon carbide may be deposited.
以上、本願のセラミックス製断熱部材及びその製造方
法について詳細に説明したが、本発明の精神から逸れな
いかぎりで、種々の異なる実施例は容易に構成できるか
ら、本発明は前記特許請求の範囲において記載した限定
以外、特定の実施例に制約されるものではない。The ceramic heat insulating member of the present application and the method for manufacturing the same have been described above in detail, but various different embodiments can be easily configured without departing from the spirit of the present invention. Other than the stated limitations, there is no limitation to any particular embodiment.
（発明の効果） 以上説明したように、本発明によれば、ジルコニアに
マグネシアと窒化硼素とを添加し焼結して断熱部材の基
体を作成したので、マグネシアの添加よりジルコニアを
部分安定化し、部材内部に正方晶ジルコニアの微細結晶
を分散させ基体の機械的強度、特に破壊靭性を向上さ
せ、また、窒化硼素を添加したので、焼結時に基体内部
に形成される気孔を微細化し均一に分散させることがで
き、強度の偏りを防止し応力の集中を解消して機械的強
度を向上させることができ、更に部材表面の孔部をCVD
法あるいはイオンプレーティング法により形成される高
強度で高温安定性に優れたセラミックスである窒化珪素
あるいは炭化珪素により密封することにより部材の気密
性を向上させることができるセラミックス製断熱部材及
びその製造方法を提供できる。(Effect of the invention) As described above, according to the present invention, since magnesia and boron nitride were added to zirconia and sintered to form a substrate for the heat insulating member, zirconia was partially stabilized by addition of magnesia, Fine particles of tetragonal zirconia are dispersed inside the member to improve the mechanical strength of the substrate, especially fracture toughness.Because boron nitride is added, the pores formed inside the substrate during sintering are finely dispersed evenly. It is possible to prevent unevenness in strength, eliminate stress concentration, and improve mechanical strength.
Insulation member made by ceramics or ion plating method, which can improve the airtightness of the member by sealing with silicon nitride or silicon carbide which is high strength and excellent in stability at high temperature, and its manufacturing method Can be provided.
Claims (4)
基体と、該基体表面上に1100℃以下の状態で被着される
高強度で高温安定性に優れたセラミックスからなる前記
該基体表面の孔部を密封する密封層とからなるセラミッ
クス製断熱部材において、 前記部分安定化ジルコニアは、マグネシアにて部分安定
化され、かつ微孔形成剤として窒化硼素を含有すること
を特徴とするセラミックス製断熱部材。1. A substrate made of porous partially stabilized zirconia, and a substrate made of high-strength and excellent high-temperature stability ceramics deposited on the substrate surface at a temperature of 1100 ° C. or less. A ceramic heat insulating member comprising a sealing layer for sealing holes, wherein the partially stabilized zirconia is partially stabilized by magnesia and contains boron nitride as a micropore forming agent. Element.
珪素もしくは炭化珪素であることを特徴とする請求項
（１）記載のセラミックス製断熱部材。2. The ceramic heat insulating member according to claim 1, wherein the ceramic constituting the sealing layer is silicon nitride or silicon carbide.
孔形成剤として窒化硼素粉末の混合物からなる仮成型体
を作成するステップと、該仮成型体を焼結炉内にて加熱
しジルコニアが立方晶ジルコニアに相転移する温度以上
で仮成型体を焼結し基体を作成するステップと、該焼結
後に基体を冷却し基体内部に正方晶ジルコニアの微細結
晶を分散析出させ基体に含有されるジルコニアを部分安
定化するステップと、該部分安定化された基体表面に基
体内部の正方晶ジルコニアが立方晶ジルコニアへ相転移
する温度より低温度の状態で高強度で高温安定性に優れ
たセラミックスを被着させ基体表面の孔部を密封するス
テップとを有することを特徴とするセラミックス製断熱
部材の製造方法。3. A step of forming a temporary molded body made of a mixture of zirconia powder, magnesia powder and boron nitride powder as a micropore forming agent, and heating the temporary molded body in a sintering furnace to form cubic crystals of zirconia. A step of forming a base body by sintering the preformed body at a temperature not lower than the phase transition to zirconia, and cooling the base body after the sintering to disperse and precipitate fine crystals of tetragonal zirconia inside the base body to form zirconia Partially stabilizing step and depositing ceramics with high strength and high temperature stability on the surface of the partially stabilized substrate at a temperature lower than the temperature at which the tetragonal zirconia inside the substrate undergoes phase transition to cubic zirconia. And a step of sealing the holes on the surface of the base body.
珪素であることを特徴とする請求項（３）記載のセラミ
ックス製断熱部材の製造方法。4. The method for manufacturing a ceramic heat insulating member according to claim 3, wherein the ceramic is silicon nitride or silicon carbide.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1151236A JP2543408B2 (en) | 1989-06-14 | 1989-06-14 | Ceramic heat insulating member and manufacturing method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1151236A JP2543408B2 (en) | 1989-06-14 | 1989-06-14 | Ceramic heat insulating member and manufacturing method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0316983A JPH0316983A (en) | 1991-01-24 |
| JP2543408B2 true JP2543408B2 (en) | 1996-10-16 |
Family
ID=15514227
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1151236A Expired - Lifetime JP2543408B2 (en) | 1989-06-14 | 1989-06-14 | Ceramic heat insulating member and manufacturing method thereof |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2543408B2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04364882A (en) * | 1991-06-12 | 1992-12-17 | Matsushita Electric Works Ltd | Method for manufacturing hair cutter blade |
| WO2015080065A1 (en) * | 2013-11-26 | 2015-06-04 | 日本碍子株式会社 | Porous material and heat insulating film |
| CN109265130A (en) * | 2018-11-06 | 2019-01-25 | 中集绿建环保科技有限公司 | A kind of granite slab and method using the preparation of granite tailing |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS59141472A (en) * | 1983-01-31 | 1984-08-14 | 三井造船株式会社 | Porous ceramic member surface minutening method |
| JPS61158883A (en) * | 1984-12-28 | 1986-07-18 | 日本特殊陶業株式会社 | Coated zirconia base sintered body |
| JPS61222975A (en) * | 1985-03-28 | 1986-10-03 | 三井造船株式会社 | Surface fining method for porous body |
-
1989
- 1989-06-14 JP JP1151236A patent/JP2543408B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0316983A (en) | 1991-01-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP3581879B2 (en) | Alumina porous body and method for producing the same | |
| JPH07277814A (en) | Alumina-based ceramic sintered compact | |
| JP6651628B2 (en) | High thermal conductivity silicon nitride sintered body and method for producing the same | |
| WO2022222778A1 (en) | Fine ceramic material formed by means of ceramic precursor framework and preparation method therefor and use thereof | |
| KR960016070B1 (en) | Sintered aluminium nitride and its production | |
| JP2882575B2 (en) | High thermal conductive silicon nitride ceramics and method for producing the same | |
| KR100500495B1 (en) | Aluminium nitride ceramics, members for use in a system for producing semiconductors, and corrosion resistant members | |
| JP2543408B2 (en) | Ceramic heat insulating member and manufacturing method thereof | |
| JPH02296771A (en) | Composite ceramic and its production | |
| WO2015025951A1 (en) | Porous ceramic and method for producing same | |
| JP2744938B2 (en) | Porous high-strength low thermal conductive silicon nitride ceramics and method for producing the same | |
| JPH0212893B2 (en) | ||
| JP2002128563A (en) | Ceramic member for thermal treatment which has good thermal shock resistance | |
| CN109694254A (en) | A method of compact silicon nitride ceramics are prepared using single sintering aid is normal pressure-sintered | |
| KR20170109515A (en) | Porous silicon nitride sintered body and method for manufacturing the same | |
| Hirata et al. | Processing of high performance silicon carbide | |
| EP0885858B1 (en) | Recrystallized silicon carbide sintered material and manufacturing method thereof | |
| Xu et al. | α‐SiAlON Ceramics Obtained by Slip Casting and Pressureless Sintering | |
| JPH0224789B2 (en) | ||
| JP2001354479A (en) | Aluminum nitride sintered compact and its manufacturing method | |
| KR102216429B1 (en) | Cordierite based ceramic composition for use of ceramic heater | |
| JPH01145380A (en) | Production of silicon nitride sintered form | |
| JPS63252967A (en) | Manufacture of silicon nitride base sintered body | |
| JPH02167857A (en) | Highly tough mullite-based calcined body and production thereof | |
| JP2024053480A (en) | Method for producing sintered silicon nitride |