JPH07215774A - Method for reinforcing ceramic compact - Google Patents

Method for reinforcing ceramic compact

Info

Publication number
JPH07215774A
JPH07215774A JP6026142A JP2614294A JPH07215774A JP H07215774 A JPH07215774 A JP H07215774A JP 6026142 A JP6026142 A JP 6026142A JP 2614294 A JP2614294 A JP 2614294A JP H07215774 A JPH07215774 A JP H07215774A
Authority
JP
Japan
Prior art keywords
ceramic
component
fiber
content
ratio
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
Application number
JP6026142A
Other languages
Japanese (ja)
Inventor
Yoshikatsu Higuchi
義勝 樋口
Masanori Okabe
昌規 岡部
Yasunobu Kawakami
泰伸 川上
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Honda Motor Co Ltd
Original Assignee
Honda Motor Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Honda Motor Co Ltd filed Critical Honda Motor Co Ltd
Priority to JP6026142A priority Critical patent/JPH07215774A/en
Priority to DE1995102385 priority patent/DE19502385C2/en
Publication of JPH07215774A publication Critical patent/JPH07215774A/en
Priority to US08/877,953 priority patent/US5856253A/en
Pending legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/62227—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products obtaining fibres
    • C04B35/62272—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products obtaining fibres based on non-oxide ceramics
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/515—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics
    • C04B35/58—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on borides, nitrides, i.e. nitrides, oxynitrides, carbonitrides or oxycarbonitrides or silicides
    • C04B35/584—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on borides, nitrides, i.e. nitrides, oxynitrides, carbonitrides or oxycarbonitrides or silicides based on silicon nitride
    • C04B35/593—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on borides, nitrides, i.e. nitrides, oxynitrides, carbonitrides or oxycarbonitrides or silicides based on silicon nitride obtained by pressure sintering
    • C04B35/5935—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on borides, nitrides, i.e. nitrides, oxynitrides, carbonitrides or oxycarbonitrides or silicides based on silicon nitride obtained by pressure sintering obtained by gas pressure sintering
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/71—Ceramic products containing macroscopic reinforcing agents
    • C04B35/78—Ceramic products containing macroscopic reinforcing agents containing non-metallic materials
    • C04B35/80—Fibres, filaments, whiskers, platelets, or the like

Abstract

PURPOSE:To improve mechanical strength and cracking resistance by adding a ceramic component having a specified fiber form to a ceramic component acting as a matrix. CONSTITUTION:Melt-spun polysilazane is fired to obtain amorphous or crystalline ceramic fibers (A) contg. Si and N as essential components and having <=10wt.% C+O content, a ratio of 0.8-2 as the ratio of C to O, <=20mum average diameter and 10-600mum fiber length. The component A is dispersed in an aq. ammonia soln. or an org. solvent to prepare a slurry and 40-60vol.% of this slurry is mixed with a ceramic component (B) having 3-0.01mum average particle diameter and acting as a matrix so as to regulate the ratio of the O content of the component A to that of the component B to <=6, the ratio of the Si content of the component A to that of the component B to >=0.8 and the ratio of the N content of the component A to that of the component B to >=0.6. Additives (C) including 3-8wt.% sintering aid such as oxide of a group IIIA element may further be added if necessary. The resulting mixture is dried and compacted.

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【産業上の利用分野】本発明は、セラミックファイバー
を添加することによるセラミック成形体の強化方法に関
し、特に、セラミック成形体の焼成特性に悪影響を与え
ないセラミックファイバーを添加することによるセラミ
ック成形体の強化方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for strengthening a ceramic molded body by adding a ceramic fiber, and more particularly, to a ceramic molded body produced by adding a ceramic fiber which does not adversely affect the firing characteristics of the ceramic molded body. Regarding strengthening method.

【０００２】[0002]

【従来の技術】セラミック焼結体は一般にセラミック粉
末を一定の形に成形して成形体（グリーン）とした後、
焼結させることにより得られる。セラミックスは一旦焼
結すると加工が困難であるので、焼結前に所望の形状に
成形する。このようなセラミック成形体の製造方法とし
ては、金型を用いてプレスする方法、射出成形法、セラ
ミックの泥漿を石膏型に鋳込むことによるスリップキャ
スト法、ラバープレスによる冷間静水圧プレス法等があ
るが、薄肉のものや複雑な形状の成形体を得るには、セ
ラミックの泥漿（又は樹脂等の混練物）を所定の形状の
型に注入することにより成形するスリップキャスト法、
射出成形法、ドクターブレードによる成形法等が好まし
い。2. Description of the Related Art Generally, a ceramic sintered body is obtained by molding a ceramic powder into a predetermined shape to obtain a green body.
It is obtained by sintering. Since it is difficult to process ceramics once sintered, they are formed into a desired shape before sintering. As a method for manufacturing such a ceramic molded body, a method of pressing using a mold, an injection molding method, a slip casting method of casting ceramic slurry into a gypsum mold, a cold isostatic pressing method of a rubber press, etc. However, in order to obtain a thin-walled product or a molded product having a complicated shape, a slip casting method in which a ceramic slurry (or a kneaded material such as a resin) is poured into a mold having a predetermined shape,
Injection molding, doctor blade molding and the like are preferable.

【０００３】スリップキャスト法においては、セラミッ
ク原料を粉末状にして水に分散させ、得られた泥漿を石
膏型に入れ、水分を吸収透過させる。これによりセラミ
ック粉末が固まった状態の成形体（グリーン）が得られ
る。In the slip casting method, a ceramic raw material is made into a powder form and dispersed in water, and the obtained slurry is put into a gypsum mold to absorb and permeate water. As a result, a compact (green) in which the ceramic powder is solidified is obtained.

【０００４】ところで、窒化珪素系セラミックスは耐熱
性に優れ、高強度、高硬度であり、また比較的軽量でも
あるので、金属材料に代わる材料としてクローズアップ
されてきた。この窒化珪素系セラミックスは一般に難焼
結性であるために、窒化珪素粉末にＹ2 Ｏ3 やAl2 Ｏ3
等の焼結助剤やその他の添加剤の粉末を加えて上述のス
リップキャスト法等により成形体をまず製造し、これを
焼結していた。By the way, since silicon nitride ceramics are excellent in heat resistance, have high strength and hardness, and are also relatively lightweight, they have been highlighted as alternatives to metal materials. Since this silicon nitride ceramics is generally difficult to sinter, Y 2 O 3 or Al 2 O 3 is added to the silicon nitride powder.
Powders of sintering aids such as the above and other additives were added, and a molded body was first manufactured by the above-described slip casting method and the like, and this was sintered.

【０００５】しかしながら、上述のスリップキャスト法
等でセラミック成形体を作った場合、セラミック粉末に
バインダー等を配合してあるとしてもセラミック粉末粒
子間の結合力は必ずしも大きくないので、機械的強度が
大きくなく、破損するおそれが大きい。また石膏型中で
の脱水乾燥によりセラミック成形体は収縮し、亀裂が生
じやすい。このため薄肉成形体や複雑形状の成形体を破
損や亀裂のおそれなく製造することは困難であった。However, when a ceramic molded body is produced by the above-mentioned slip casting method or the like, the bonding strength between the ceramic powder particles is not necessarily large even if the binder is mixed with the ceramic powder, so that the mechanical strength is large. There is a high risk of damage. Moreover, the ceramic molded body shrinks due to dehydration and drying in the gypsum mold, and cracks easily occur. Therefore, it is difficult to manufacture a thin-walled molded product or a molded product having a complicated shape without fear of damage or cracks.

【０００６】[0006]

【発明が解決しようとする課題】そこで、本発明者ら
は、Ｓｉ、Ｎ、Ｃ及びＯ成分からなるファイバーをポリ
シラザンの熱分解により作成し、これをセラミック原料
に加え、成形体の強度を上げることを提案した（特開平
４−２３８８７４号）。しかしながら、わずかなファイ
バーの組成の違いによりセラミックスの焼成中にファイ
バーの一部が消失して、その痕が空隙になる場合のある
ことが分かってきた。特にファイバーを大量に添加した
場合、これらの空隙が多くなり、焼成体の機械的強度を
低下させる問題が出てきた。Therefore, the inventors of the present invention prepared a fiber composed of Si, N, C and O components by thermal decomposition of polysilazane, and added this to a ceramic raw material to increase the strength of a molded body. It has been proposed (JP-A-4-238874). However, it has been found that a part of the fiber may disappear during firing of the ceramic due to a slight difference in the composition of the fiber, and the trace may become a void. In particular, when a large amount of fibers are added, these voids increase, and there has been a problem that the mechanical strength of the fired product is lowered.

【０００７】従って、本発明の目的は、かかる問題点を
解消し、セラミック成形体に十分な機械的強度と耐亀裂
性を与えてその破損や亀裂を防止するとともに、焼成し
て得られるセラミックスの機械的強度を向上することが
できるセラミック成形体の強化方法を提供することであ
る。Therefore, an object of the present invention is to solve the above problems, to provide a ceramic molded body with sufficient mechanical strength and crack resistance to prevent the damage or crack, and to obtain a ceramic obtained by firing. It is an object of the present invention to provide a method for strengthening a ceramic molded body capable of improving mechanical strength.

【０００８】[0008]

【課題を解決するための手段】本発明者らは、上記目的
を達成すべく鋭意研究の結果、焼成に伴うセラミックフ
ァイバーの消失はファイバー中の酸素が炭素、珪素と反
応し、一酸化炭素、一酸化珪素を生成して離脱すること
によるものであり、セラミック成形体を成形する際に、
消失する元素Ｏ及びＣの含有量を低く抑えた特定の組成
のセラミックファイバーをセラミック原料に加えれば、
得られる成形体の強度が向上するとともに、焼結して得
られるセラミックスの機械強度が向上することを発見
し、本発明に想到した。DISCLOSURE OF THE INVENTION As a result of intensive studies to achieve the above object, the inventors of the present invention have found that the disappearance of a ceramic fiber due to firing causes oxygen in the fiber to react with carbon and silicon, carbon monoxide, This is due to the fact that silicon monoxide is generated and released, and when molding a ceramic molded body,
If a ceramic fiber having a specific composition in which the contents of the disappearing elements O and C are suppressed to a low level is added to the ceramic raw material,
The present invention was discovered by discovering that the strength of the obtained molded body is improved and the mechanical strength of the ceramic obtained by sintering is improved.

【０００９】すなわち、マトリックスとなるセラミック
成分にファイバー形態のセラミック成分を添加してセラ
ミック成形体を強化する本発明の方法は、前記ファイバ
ーの必須成分をＳｉ及びＮとし、元素Ｏ及びＣの合計含
有量を１０重量％以下にし、かつ元素Ｃの含有量と元素
Ｏの含有量との比を０．０８〜２にすることを特徴とす
る。That is, the method of the present invention in which a ceramic component in the form of fibers is added to the ceramic component serving as a matrix to reinforce the ceramic compact, the essential components of the fiber are Si and N, and the total content of the elements O and C is contained. The amount is 10% by weight or less, and the ratio of the content of the element C to the content of the element O is 0.08 to 2.

【００１０】本発明を以下に詳細に説明する。本発明は
あらゆるセラミック成形体に適用可能であるが、ここで
は窒化珪素系セラミック成形体を例にとり具体的に説明
する。The present invention is described in detail below. The present invention is applicable to any ceramic molded body, but here, a silicon nitride ceramic molded body will be specifically described as an example.

【００１１】〔１〕セラミック成形体の原料 窒化珪素を主体とするセラミックスを製造する場合、用
いる窒化珪素粉末としてはα型及びβ型のいずれも使用
することができ、またその製造法としてはSiの直接窒化
法、シリカの還元・窒化法、シリコンジイミドの熱分解
法、SiＨ4 ＋NH3 ＋Ｎ2 の気相反応法等がある。窒化珪
素粉末は平均粒径が３〜0.01μｍのものが好ましく、よ
り好ましくは1.5 〜0.1 μｍである。[1] Raw Material for Ceramic Molded Body When a ceramic mainly composed of silicon nitride is manufactured, either α type or β type can be used as the silicon nitride powder to be used, and the manufacturing method thereof is Si. Direct nitriding method, silica reduction / nitridation method, thermal decomposition method of silicon diimide, and gas phase reaction method of SiH 4 + NH 3 + N 2 . The silicon nitride powder preferably has an average particle size of 3 to 0.01 μm, more preferably 1.5 to 0.1 μm.

【００１２】なお、この窒化珪素に加えることのできる
セラミック添加剤としては、ＩＩＩＡ族、ＩＩＩＢ族、
ＩＶＢ族元素の酸化物や窒化物、炭化物が挙げられる。
一般に、アルミナ、イットリア、酸化ハフニウム、マグ
ネシア等の添加剤は窒化珪素系セラミックスにおいては
焼結助剤として作用するものである。The ceramic additives that can be added to the silicon nitride are IIIA group, IIIB group,
Examples thereof include oxides, nitrides, and carbides of group IVB elements.
In general, additives such as alumina, yttria, hafnium oxide and magnesia act as a sintering aid in silicon nitride ceramics.

【００１３】先に出願人は焼結助剤成分を繊維状として
添加しグリーン強度を上げる出願を行っているが（特開
平４−２３８８７４）、その方法では添加する助剤成分
が限定され、得られる焼結体の特性も制約される等の問
題があった。本発明では、助剤成分を繊維状として添加
し、グリーン強度を上げるのではなく、以下に詳述する
セラミックファイバーを添加してグリーン強度を向上さ
せる。The applicant has previously filed an application to increase the green strength by adding a sintering aid component in a fibrous form (Japanese Patent Laid-Open No. 238874), but in that method, the additive component added is limited and There is a problem that the characteristics of the sintered body are restricted. In the present invention, the green strength is not improved by adding the auxiliary component as a fibrous form, but by adding the ceramic fiber described in detail below to improve the green strength.

【００１４】まずセラミックファイバーとしては、不純
物としてＯ及びＣを含み、必須成分としてSi及びＮから
なる組成のアモルファス又は結晶質のセラミックファイ
バーを用いる。このセラミックファイバーにおいて、元
素Ｃと元素Ｏの合計含有量は１０重量％以下であり、元
素Ｃの含有量と元素Ｏの含有量との比が０．０８〜２、
好ましくは０．１〜１．５、より好ましくは０．２〜
１．０である。このような組成とすることで、焼結後の
セラミックスの機械的強度及び高温強度を高いものに維
持することができる。一方、この組成を外れるセラミッ
クファイバーを用いると、セラミックスの機械的強度及
び高温強度が低下する。このようなセラミックファイバ
ーとしては、ポリシラザンを溶融紡糸後、熱分解したも
のを好適に使用することができる。First, as the ceramic fiber, an amorphous or crystalline ceramic fiber containing O and C as impurities and having Si and N as essential components is used. In this ceramic fiber, the total content of the element C and the element O is 10% by weight or less, and the ratio of the content of the element C and the content of the element O is 0.08 to 2,
Preferably 0.1-1.5, more preferably 0.2-
It is 1.0. With such a composition, the mechanical strength and high temperature strength of the ceramics after sintering can be maintained high. On the other hand, if a ceramic fiber having a composition out of this range is used, the mechanical strength and high temperature strength of the ceramic will decrease. As such a ceramic fiber, one obtained by melt-spinning polysilazane and then thermally decomposing it can be preferably used.

【００１５】〔２〕ポリシラザンの製造 ここで、まずこのセラミックファイバーの製造方法につ
いて説明する。本発明に用いるセラミックファイバー
は、上述の通りポリシラザンから製造されるが、このポ
リシラザンは例えば（Ｒ2 SiＮＲ）3 等（ここでＲはＨ
又はアルキル基を示す）のシクロシラザンとクロロシラ
ン（Ｒn SiCl4-n 、ただしｎ＝０，１，２，３、ＲはＨ
又はアルキル基）とから合成することができる。以下こ
の方法を例にとり説明するが、本発明はこの方法に限定
されるものではなく、種々の方法で合成が可能である。[2] Production of Polysilazane Here, a method of producing the ceramic fiber will be described first. The ceramic fiber used in the present invention is produced from polysilazane as described above, and this polysilazane is, for example, (R 2 SiNR) 3 (where R is H
Or an alkyl group) and chlorosilane (R n SiCl 4-n , where n = 0, 1, 2, 3 and R is H
Or an alkyl group). This method will be described below as an example, but the present invention is not limited to this method and can be synthesized by various methods.

【００１６】まず、シクロシラザンとしてヘキサメチル
シクロトリシラザン（Me2 SiNH）3を用い、これにクロ
ロシランとしてトリクロロメチルシランを混合する。混
合比は、モル比でヘキサメチルシクロトリシラザン対ト
リクロロメチルシランが１：１〜１：５、好ましくは
１：３程度とする。First, hexamethylcyclotrisilazane (Me 2 SiNH) 3 is used as cyclosilazane, and trichloromethylsilane is mixed as chlorosilane. The mixing ratio of hexamethylcyclotrisilazane to trichloromethylsilane is 1: 1 to 1: 5, preferably about 1: 3, in terms of molar ratio.

【００１７】上述のヘキサメチルシクロトリシラザンと
トリクロロメチルシランとの混合物を190 〜195 ℃で加
熱還流する。これによってヘキサメチルシクロトリシラ
ザンが開環し、クロロシラザンオリゴマーが生成され
る。なお、ヘキサメチルシクロトリシラザンとトリクロ
ロメチルシランとからクロロシラザンオリゴマーを製造
する工程は12時間程度で完了する。The above-mentioned mixture of hexamethylcyclotrisilazane and trichloromethylsilane is heated to reflux at 190 to 195 ° C. As a result, hexamethylcyclotrisilazane is ring-opened to produce a chlorosilazane oligomer. The process of producing a chlorosilazane oligomer from hexamethylcyclotrisilazane and trichloromethylsilane is completed in about 12 hours.

【００１８】さらに、この溶液に対してアンモニアガス
を吹き込みアンモノリシスを行う。吹き込むアンモニア
ガスの量は１０〜９０リットル／時間、好ましくは３０
〜６０リットル／時間である。このアンモノリシスによ
り、クロロシラザンオリゴマーはアミノシラザンオリゴ
マーとなる。アンモノリシスにより副生する塩化アンモ
ニウムの結晶は吸引ろ過により分離除去する。Further, ammonia gas is blown into this solution for ammonolysis. The amount of ammonia gas blown is 10 to 90 liters / hour, preferably 30
~ 60 liters / hour. By this ammonolysis, the chlorosilazane oligomer becomes an aminosilazane oligomer. Crystals of ammonium chloride by-produced by ammonolysis are separated and removed by suction filtration.

【００１９】次に、このアミノシラザンオリゴマーを窒
素ガス等の不活性ガス中で、250 〜400 ℃程度に加熱し
ながら脱アンモニア工程を行い、熱可塑性を示す固体状
のポリシラザンを調製する。ポリシラザンの軟化点は加
熱の条件により調整可能であるが、50〜200 ℃程度が好
ましい。Next, a deammonification step is carried out while heating the aminosilazane oligomer in an inert gas such as nitrogen gas at about 250 to 400 ° C. to prepare a solid polysilazane having thermoplasticity. The softening point of polysilazane can be adjusted by heating conditions, but is preferably about 50 to 200 ° C.

【００２０】〔３〕セラミックファイバーの製造 得られたポリシラザンを軟化点以上の温度に保ってこれ
を溶融し、２５〜４００ｍ／分程度の巻き取り速度で紡
糸する。これによって５〜30μｍ径のファイバーが得ら
れる。[3] Production of Ceramic Fiber The obtained polysilazane is melted while being kept at a temperature equal to or higher than the softening point, and spun at a winding speed of about 25 to 400 m / min. This gives fibers with a diameter of 5 to 30 μm.

【００２１】得られたファイバーを窒素ガスでバブリン
グしたクロロシラン、例えばトリクロロメチルシランを
流してファイバーに付加する。付加するクロロシランの
流量はバブリングする窒素ガスの流量として１０〜５０
０ｍｌ／分とするのが好ましい。処理時間については処
理するファイバーの量により適宜調整するが、通常１〜
４８時間で終了する。また処理温度はファイバーの軟化
温度以下とする。このクロロシランの付加により、ファ
イバー表面にクロロシランとポリシラザンの架橋反応が
起こる。The obtained fiber is added to the fiber by flowing a chlorosilane bubbled with nitrogen gas, for example, trichloromethylsilane. The flow rate of the added chlorosilane is 10 to 50 as the flow rate of the nitrogen gas to be bubbled.
It is preferably 0 ml / min. The treatment time is appropriately adjusted depending on the amount of fibers to be treated, but usually 1 to
It ends in 48 hours. Further, the treatment temperature is set to the softening temperature of the fiber or lower. The addition of this chlorosilane causes a crosslinking reaction between chlorosilane and polysilazane on the fiber surface.

【００２２】次に、アンモニアガスを流しながら不融化
処理を行う。不融化処理温度は５０℃〜ファイバーの軟
化温度とするのが好ましい。また処理時間は、この場合
も処理するファイバー量によって適宜調整する。アンモ
ニアの存在下で不融化処理を行うことにより、ファイバ
ー表面の塩素基及び炭化水素基がアンモニアによって置
換され、ファイバー表面の架橋反応が更に進むため、不
融化が達成される。Next, the infusibilizing treatment is carried out while flowing the ammonia gas. The infusibilizing treatment temperature is preferably 50 ° C. to the softening temperature of the fiber. In addition, the treatment time is adjusted as appropriate depending on the amount of fibers to be treated. By performing the infusibilization treatment in the presence of ammonia, chlorine groups and hydrocarbon groups on the fiber surface are replaced by ammonia, and the crosslinking reaction on the fiber surface further proceeds, so that infusibilization is achieved.

【００２３】最後に、ファイバーをアンモニア又は水素
及びこれらと窒素との混合ガス中で、800 〜1400℃で
０．５〜４時間程度焼成することにより、ファイバー中
のＣ、Ｏ含有量を減少させ、上述の組成（SiとＮとＣ、
さらに不純物としてＯを含む）のセラミックファイバー
を得る。最終的に得られたセラミックファイバーの径は
１〜20μｍ程度となる。Finally, the C and O contents in the fiber are reduced by firing the fiber in ammonia or hydrogen and a mixed gas of these and nitrogen at 800 to 1400 ° C. for 0.5 to 4 hours. , The above composition (Si, N and C,
Further, O is contained as an impurity) to obtain a ceramic fiber. The diameter of the finally obtained ceramic fiber is about 1 to 20 μm.

【００２４】なお、セラミック成形体に用いるセラミッ
クファイバーは平均直径が２０μｍ以下、特に３〜10μ
ｍ、繊維長は10〜 500μｍ、特に 100〜 300μｍに調整
することが望ましい。平均直径及びファイバー長が大き
くなりすぎると分散性が低下し、焼結後の成形品に欠陥
が生じるおそれが大きく、また焼結密度が低下する。一
方、平均直径やファイバー長が小さすぎると、セラミッ
クファイバーの添加による補強効果が十分に得られな
い。The ceramic fiber used for the ceramic molded body has an average diameter of 20 μm or less, particularly 3 to 10 μm.
m, and the fiber length is preferably adjusted to 10 to 500 μm, particularly 100 to 300 μm. If the average diameter and the fiber length are too large, the dispersibility decreases, the molded product after sintering is likely to have defects, and the sintered density decreases. On the other hand, if the average diameter or the fiber length is too small, the reinforcing effect due to the addition of the ceramic fiber cannot be sufficiently obtained.

【００２５】〔４〕セラミック成形体の製造 上述のセラミックファイバーを、焼結助剤成分と主成分
の窒化珪素とからなるマトリックス成分に添加してセラ
ミック成形体を製造するが、本発明によるセラミック成
形体の強化方法においては、ファイバー中の元素Ｏの含
有量と前記マトリックス中の元素Ｏの含有量との比が６
以下、前記ファイバー中の元素Ｓｉの含有量と前記マト
リックス中の元素Ｓｉの含有量との比が０．８以上、前
記ファイバー中の元素Ｎの含有量と前記マトリックス中
の元素Ｎの含有量との比が０．６以上となるように配合
するのが好ましい。このように配合することによって、
セラミック成形体中の分解に関与する酸素含有量を抑え
ることができ、焼成時に消失する炭素、珪素の酸化物の
量を低く抑えることができる。[4] Manufacture of Ceramic Molded Body The above-mentioned ceramic fiber is added to a matrix component composed of a sintering aid component and silicon nitride as a main component to manufacture a ceramic molded body. In the body strengthening method, the ratio of the content of the element O in the fiber to the content of the element O in the matrix is 6
Hereinafter, the ratio of the content of element Si in the fiber and the content of element Si in the matrix is 0.8 or more, the content of element N in the fiber and the content of element N in the matrix. It is preferable that the ratio is 0.6 or more. By blending in this way,
The oxygen content involved in decomposition in the ceramic molded body can be suppressed, and the amount of carbon and silicon oxides that disappear during firing can be suppressed to a low level.

【００２６】なお、窒化珪素粉末は７２重量％以上、上
述したポリシラザンから製造されるセラミックファイバ
ーは１〜２０重量％の割合とするのがよい。またAl2 Ｏ
3 、Ｙ2 Ｏ3 、ＨｆＯ2 等の焼結助剤の配合量は３〜８
重量％とするのがよい。セラミックファイバーの配合量
が上記下限値より少ないと補強作用が十分でなく、セラ
ミック成形体に破損や亀裂が起こりやすくなる。The silicon nitride powder is preferably 72% by weight or more, and the ceramic fiber produced from the polysilazane is preferably 1 to 20% by weight. Also Al 2 O
The compounding amount of the sintering aid such as 3 , Y 2 O 3 and HfO 2 is 3 to 8
It is good to set it as the weight%. If the compounding amount of the ceramic fiber is less than the above lower limit value, the reinforcing effect is insufficient and the ceramic molded body is likely to be damaged or cracked.

【００２７】本発明のセラミック成形体は上記成分の他
に、少量のワックスもしくは樹脂等の有機バインダーや
有機物又は金属繊維等を、所望により含有してもよい。In addition to the above-mentioned components, the ceramic molded body of the present invention may optionally contain a small amount of an organic binder such as wax or resin, an organic substance or metal fiber.

【００２８】次に本発明のセラミック成形体を製造する
方法について説明する。まず主成分となる窒化珪素粉
末、Al2 Ｏ3 、Ｙ2 Ｏ3 、ＨｆＯ2 等の焼結助剤、及び
ポリシラザンから製造されたセラミックファイバーを水
又は有機溶媒からなる分散媒に均一に分散させ、泥漿と
する。この際全てのセラミック原料を同時に配合しても
よいが、まず分散性のよいSi3 Ｎ4 粉末と焼結助剤粉末
を配合した後で、ポリシラザンから製造されたセラミッ
クファイバーを配合するのが好ましい。Next, a method for producing the ceramic molded body of the present invention will be described. First, silicon nitride powder, which is the main component, sintering aids such as Al 2 O 3 , Y 2 O 3 and HfO 2 , and ceramic fibers produced from polysilazane are uniformly dispersed in a dispersion medium composed of water or an organic solvent. , Let it be a slurry. At this time, all the ceramic raw materials may be blended at the same time, but it is preferable that the Si 3 N 4 powder having a good dispersibility and the sintering aid powder are blended first, and then the ceramic fiber produced from polysilazane is blended. .

【００２９】分散媒として水を使用する場合、アンモニ
ア水を加えるのが好ましい。NH4 OHは分散性が良いた
め、高濃度、低粘度のセラミックスラリーを調製するこ
とができ、乾燥後、高密度の成形体を得ることができ
る。また、焼結後の成形品にナトリウム、カルシウム等
の不純物が残らず、高純度の焼結体を得ることができ、
更には粒界のガラス相を減少でき、焼結体の高温強度を
高く保持することができる（粒界のガラス相が増加する
と、焼結体の高温での強度が低下する。）。また分散媒
として、ホルムアミドのような極性の高い有機溶媒を使
用するのも、窒化珪素の酸化を防止し、焼結体の高温強
度を高く保つうえで好適である。本発明において特に制
限はないが、成形性の観点から泥漿の濃度は40〜60体積
％とするのが好ましい。When water is used as the dispersion medium, it is preferable to add aqueous ammonia. Since NH 4 OH has good dispersibility, it is possible to prepare a high-concentration, low-viscosity ceramic slurry, and it is possible to obtain a high-density molded body after drying. Further, impurities such as sodium and calcium do not remain in the molded product after sintering, and a high-purity sintered body can be obtained,
Furthermore, the glass phase at the grain boundaries can be reduced, and the high temperature strength of the sintered body can be kept high (when the glass phase at the grain boundaries increases, the strength of the sintered body at high temperatures decreases). It is also suitable to use a highly polar organic solvent such as formamide as the dispersion medium in order to prevent the oxidation of silicon nitride and keep the high temperature strength of the sintered body high. Although there is no particular limitation in the present invention, it is preferable that the concentration of the slurry is 40 to 60% by volume from the viewpoint of moldability.

【００３０】本発明において、成形体を成形するには、
射出成形、スリップキャスト成形、ドクターブレードに
よる成形等が適用されるが、特にスリップキャスト成形
の場合に良好な結果が得られる。In the present invention, in order to mold a molded body,
Injection molding, slip cast molding, molding with a doctor blade, etc. are applied, but good results are obtained especially in the case of slip cast molding.

【００３１】最後に得られた窒化珪素系セラミック成形
体を焼結する。この焼結工程において、成形体中のセラ
ミックファイバーはα及びβ−Ｓｉ3 Ｎ4 へ変化し、も
って均一なセラミックスが形成される。これにより機械
的特性及び耐熱性に良好な焼結体が得られる。The finally obtained silicon nitride ceramic molded body is sintered. In this sintering step, the ceramic fibers in the compact are changed to α and β-Si 3 N 4 , and uniform ceramics are formed. Thereby, a sintered body having good mechanical properties and heat resistance can be obtained.

【００３２】[0032]

【作用】本発明の方法によれば、セラミック粉末を固め
てなる非常に破損し易い成形体を、セラミックファイバ
ーを補強材として使用することにより補強し、セラミッ
ク成形体の機械的強度、伸び、耐歪性等を大幅に向上さ
せることができる。その上特定組成のセラミックファイ
バーを添加することにより、焼成時におけるセラミック
ファイバーの消失を低減させることができ、焼結体の機
械的強度を向上させることができる。According to the method of the present invention, a very fragile compact formed by solidifying ceramic powder is reinforced by using a ceramic fiber as a reinforcing material, and the mechanical strength, elongation and resistance of the ceramic compact are improved. It is possible to significantly improve distortion and the like. Furthermore, by adding the ceramic fiber having a specific composition, it is possible to reduce the disappearance of the ceramic fiber during firing, and it is possible to improve the mechanical strength of the sintered body.

【００３３】[0033]

【実施例】本発明を以下の実施例により更に詳細に説明
する。実施例１ 〔１〕ポリシラザンの合成 冷却塔及びコンデンサを備え、窒素ガスで十分置換した
500mlの三つ口フラスコに、ヘキサメチルシクロトリシ
ラザン５４．８ｇ、トリクロロメチルシラン１１１ｇ
（ヘキサメチルシクロトリシラザン：トリクロロメチル
シランのモル比は１：３である。）を入れ、マントルヒ
ーターにより加熱して１９０〜１９５℃に保った状態で
１２時間加熱還流した。室温に冷却した後、副生された
塩化アンモニウムを濾過し、クロロシラザンオリゴマー
１３６ｇを得た。The present invention will be described in more detail by the following examples. Example 1 [1] Synthesis of polysilazane A cooling tower and a condenser were provided, and nitrogen gas was sufficiently replaced.
Hexamethylcyclotrisilazane 54.8 g, trichloromethylsilane 111 g, in a 500 ml three-necked flask.
(The molar ratio of hexamethylcyclotrisilazane: trichloromethylsilane is 1: 3) was added, and the mixture was heated by a mantle heater and heated under reflux for 12 hours while being maintained at 190 to 195 ° C. After cooling to room temperature, ammonium chloride produced as a by-product was filtered to obtain 136 g of a chlorosilazane oligomer.

【００３４】メカニカルスターラー、冷却管及び吹き込
み管を備え、窒素で十分置換した２リットルの三口フラ
スコに得られたクロロシラザンオリゴマー１００ｇを入
れ、約１リットルのシクロヘキサンを溶媒として加え、
氷冷し、攪拌しながらアンモニアガスを約６０リットル
／時間の割合で４時間吹き込んでアンモノリシスを行っ
た。その後、副生された塩化アンモニウムを吸引濾過
し、さらに溶媒を除いて無色の粘性液体（アミノシラザ
ンオリゴマー）７６ｇを得た。100 g of the obtained chlorosilazane oligomer was placed in a 2 liter three-necked flask equipped with a mechanical stirrer, a cooling tube and a blowing tube, and the atmosphere was sufficiently replaced with nitrogen, and about 1 liter of cyclohexane was added as a solvent.
Ammonolysis was performed by cooling with ice and blowing ammonia gas at a rate of about 60 liters / hour for 4 hours while stirring. Thereafter, ammonium chloride produced as a by-product was suction filtered, and the solvent was further removed to obtain 76 g of a colorless viscous liquid (aminosilazane oligomer).

【００３５】得られたアミノシラザンオリゴマー５０ｇ
を反応容器に入れ、窒素気流中、３５０℃の温度で３０
分間熱処理を行い、熱可塑性を示す固体ポリシラザン３
２ｇを得た。ポリシラザンの分子量をゲルパーミエーシ
ョンクロマトグラフィ（ＧＰＣ）法により求めた結果、
ポリシラザンの数平均分子量は１５００であった。ま
た、軟化点を荷重１ｇのペネトレーション法により測定
した結果、軟化点は８６℃であった。50 g of the obtained aminosilazane oligomer
Was placed in a reaction vessel, and the temperature was set to 350 ° C. in a nitrogen stream for 30 hours.
Solid polysilazane 3 showing thermoplasticity after heat treatment for 3 minutes
2 g was obtained. As a result of obtaining the molecular weight of polysilazane by the gel permeation chromatography (GPC) method,
The number average molecular weight of polysilazane was 1500. The softening point was measured by a penetration method with a load of 1 g, and the softening point was 86 ° C.

【００３６】〔２〕セラミックファイバーの製造 このポリシラザンを銅製の紡糸ノズルに入れ、１８０℃
に３０分間保持して脱気処理を行った後、温度を１３０
℃まで下げて１０分間保持し、圧力０．２ｋｇ／ｃｍ2
の窒素ガスで溶融したポリシラザンをノズルより押し出
し、直径１２０ｍｍのボビンに７０ｍ／分の速度で巻き
取って紡糸した。得られたゲル状ファイバーの平均直径
は１０〜２０μｍであった。[2] Manufacture of Ceramic Fiber This polysilazane was put into a spinning nozzle made of copper and heated at 180 ° C.
After degassing by holding at room temperature for 30 minutes,
Reduce to ℃ and hold for 10 minutes, pressure 0.2 kg / cm 2
Polysilazane melted with nitrogen gas was extruded from a nozzle, wound on a bobbin having a diameter of 120 mm at a speed of 70 m / min, and spun. The average diameter of the obtained gel-like fiber was 10 to 20 μm.

【００３７】約１００ｍｍにチョッピングしたファイバ
ー５０ｇをガス導入管を備えたアルミナ質管状炉に入
れ、窒素ガスにより置換した後、管内に窒素ガスでバブ
リングしたトリクロロメチルシランを３００ｍｌ／分の
流量で１０時間流した。50 g of fibers chopped to about 100 mm were placed in an alumina tubular furnace equipped with a gas introduction tube, and after substituting with nitrogen gas, trichloromethylsilane bubbled with nitrogen gas was introduced into the tube for 10 hours at a flow rate of 300 ml / min. Shed

【００３８】炉内温度を５℃／分の速度で８０℃まで上
昇し、アンモニアガスを５００ｍｌ／分の流量で４時間
流し、不融化処理を行った。続いて、アンモニアガスの
流量を１００ｍｌ／分とし、昇温速度を１０℃／分で１
２００℃まで昇温し、３０分間保持して熱分解処理を行
い、無機セラミックファイバー２３ｇを得た。The temperature inside the furnace was raised to 80 ° C. at a rate of 5 ° C./min, and ammonia gas was flowed at a flow rate of 500 ml / min for 4 hours to carry out the infusibilizing treatment. Subsequently, the flow rate of the ammonia gas was set to 100 ml / min, and the temperature rising rate was set to 1 ° C./min.
The temperature was raised to 200 ° C., and held for 30 minutes for thermal decomposition treatment to obtain 23 g of an inorganic ceramic fiber.

【００３９】得られたセラミックファイバーは、直径８
〜１５μｍの白色ファイバーであり、成形体の補強に必
要な引張強度のレベル（30kg／mm2 以上）に達してい
た。このセラミックファイバーの元素分析を行い、元素
Ｓｉ、Ｎ、Ｃ及びＯの含有率を表１に示す。The obtained ceramic fiber has a diameter of 8
It was a white fiber of -15 μm and reached the level of tensile strength (30 kg / mm 2 or more) necessary for reinforcing the molded body. Elemental analysis of this ceramic fiber was performed, and the content rates of the elements Si, N, C and O are shown in Table 1.

【００４０】〔３〕セラミック成形体の製造 ミキサーにて粉砕したセラミックファイバーのうち、＃
６００μｍのフィルターを通過し、＃３５０μｍのフィ
ルターを通過しないものを用いた。これらのファイバー
の長さは４００〜６００μｍである。[3] Manufacture of Ceramic Molded Body Among ceramic fibers crushed by a mixer, #
A filter that passed a 600 μm filter and did not pass a # 350 μm filter was used. The length of these fibers is 400-600 μm.

【００４１】窒化珪素粉末（平均粒径0.5 μｍ）９５．
３８重量％と、イットリア粉末（平均粒径0.8 μｍ）
１．５重量％と、酸化ハフニウム粉末（平均粒径１μ
ｍ）２．５重量％とを混合したスラリーに、上記ファイ
バー０．６２重量％を添加し、均一に混合した後、幅３
０ｍｍ、高さ６ｍｍ、長さ５０ｍｍの成形体をスリップ
キャスト法により作製した。Silicon nitride powder (average particle size 0.5 μm) 95.
38% by weight, yttria powder (average particle size 0.8 μm)
1.5% by weight and hafnium oxide powder (average particle size 1μ
m) To the slurry mixed with 2.5% by weight, 0.62% by weight of the above fiber was added and uniformly mixed, and then a width of 3
A molded body having a length of 0 mm, a height of 6 mm and a length of 50 mm was produced by the slip casting method.

【００４２】なお、この成形体は取り扱い中に破損した
り、ヒビが入ったりするようなことがなく、また乾燥後
の収縮も小さかった。The molded body did not break or crack during handling, and the shrinkage after drying was small.

【００４３】〔４〕セラミック焼結体の製造 次いで、この成形体を窒素ガス中（圧力９ａｔｍ）で１
９００℃の温度にて４時間焼結した。得られた窒化珪素
焼結体から幅４ｍｍ、高さ３ｍｍ、長さ４０ｍｍの角柱
を切り出して、室温及び１４００℃での曲げ強度をＪＩ
Ｓ Ｒ１６０１（１９８１) に準拠して測定した。結果
を表２に示す。また、焼成したセラミックスマトリック
ス中のファイバーの電子顕微鏡写真を図１に示す。[4] Manufacture of Ceramic Sintered Body Next, this molded body was subjected to 1 in nitrogen gas (pressure: 9 atm).
It was sintered at a temperature of 900 ° C. for 4 hours. A rectangular column having a width of 4 mm, a height of 3 mm and a length of 40 mm was cut out from the obtained silicon nitride sintered body, and the bending strength at room temperature and 1400 ° C. was measured by JI.
It was measured according to S R1601 (1981). The results are shown in Table 2. An electron micrograph of the fibers in the fired ceramic matrix is shown in FIG.

【００４４】比較例１ 不融化処理の条件と熱分解処理の雰囲気ガス以外は実施
例１と同じ方法で行った。不融化処理は、炉内温度４０
℃、湿度９０％の雰囲気で６４時間行い、熱分解処理は
窒素ガス雰囲気（圧力１ａｔｍ）下で行った。得られた
セラミックファイバーの元素分析を行い、元素Ｓｉ、
Ｎ、Ｃ及びＯの含有率を表１に示す。得られた窒化珪素
焼結体も実施例１と同様に室温及び１４００℃での曲げ
強度を測定し、結果を表２に示す。また、焼成したセラ
ミックスマトリックス中のファイバーの電子顕微鏡写真
を図２に示す。 Comparative Example 1 The same method as in Example 1 was carried out except for the condition of the infusibilizing treatment and the atmosphere gas of the thermal decomposition treatment. The infusibilizing process is performed at a furnace temperature of 40
It was performed for 64 hours in an atmosphere of 90 ° C. and humidity of 90%, and the thermal decomposition treatment was performed in a nitrogen gas atmosphere (pressure of 1 atm). Elemental analysis of the obtained ceramic fiber
The contents of N, C and O are shown in Table 1. The bending strength of the obtained silicon nitride sintered body was measured at room temperature and 1400 ° C. in the same manner as in Example 1, and the results are shown in Table 2. An electron micrograph of the fibers in the fired ceramic matrix is shown in FIG.

【００４５】比較例２ 不融化処理の条件と熱分解処理の雰囲気ガス以外は実施
例１と同じ方法で行った。不融化処理は、炉内温度４０
℃、湿度９０％の雰囲気で４８時間行い、熱分解処理は
窒素ガス雰囲気（圧力１ａｔｍ）下で行った。得られた
セラミックファイバーの元素分析を行い、元素Ｓｉ、
Ｎ、Ｃ及びＯの含有率を表１に示す。得られた窒化珪素
焼結体も実施例１と同様に室温及び１４００℃での曲げ
強度を測定し、結果を表２に示す。 Comparative Example 2 The same method as in Example 1 was carried out except for the condition of the infusibilizing treatment and the atmosphere gas of the thermal decomposition treatment. The infusibilizing process is performed at a furnace temperature of 40
It was carried out for 48 hours in an atmosphere of ° C and humidity of 90%, and the thermal decomposition treatment was carried out in a nitrogen gas atmosphere (pressure of 1 atm). Elemental analysis of the obtained ceramic fiber
The contents of N, C and O are shown in Table 1. The bending strength of the obtained silicon nitride sintered body was measured at room temperature and 1400 ° C. in the same manner as in Example 1, and the results are shown in Table 2.

【００４６】比較例３ 不融化処理の条件と熱分解処理の雰囲気ガス以外は実施
例１と同じ方法で行った。不融化処理は、炉内温度４０
℃、湿度９０％の雰囲気で６４時間行い、熱分解処理は
水素ガス雰囲気（圧力１ａｔｍ）下で行った。得られた
セラミックファイバーの元素分析を行い、元素Ｓｉ、
Ｎ、Ｃ及びＯの含有率を表１に示す。得られた窒化珪素
焼結体も実施例１と同様に室温及び１４００℃での曲げ
強度を測定し、結果を表２に示す。 Comparative Example 3 The same method as in Example 1 was carried out except for the condition of the infusibilizing treatment and the atmosphere gas of the thermal decomposition treatment. The infusibilizing process is performed at a furnace temperature of 40
It was carried out in an atmosphere of 90 ° C and humidity of 90% for 64 hours, and the thermal decomposition treatment was carried out in a hydrogen gas atmosphere (pressure 1 atm). Elemental analysis of the obtained ceramic fiber
The contents of N, C and O are shown in Table 1. The bending strength of the obtained silicon nitride sintered body was measured at room temperature and 1400 ° C. in the same manner as in Example 1, and the results are shown in Table 2.

【００４７】比較例４ 不融化処理の条件と熱分解処理の雰囲気ガス以外は実施
例１と同じ方法で行った。不融化処理は、炉内温度４０
℃、湿度９０％の雰囲気で６４時間行い、熱分解処理は
水素ガス雰囲気（圧力１０ａｔｍ）下で行った。得られ
たセラミックファイバーの元素分析を行い、元素Ｓｉ、
Ｎ、Ｃ及びＯの含有率を表１に示す。得られた窒化珪素
焼結体も実施例１と同様に室温及び１４００℃での曲げ
強度を測定し、結果を表２に示す。 Comparative Example 4 The same method as in Example 1 was carried out except for the condition of the infusibilizing treatment and the atmosphere gas of the thermal decomposition treatment. The infusibilizing process is performed at a furnace temperature of 40
It was performed for 64 hours in an atmosphere of 90 ° C. and a humidity of 90%, and the thermal decomposition treatment was performed in a hydrogen gas atmosphere (pressure of 10 atm). Elemental analysis of the obtained ceramic fiber
The contents of N, C and O are shown in Table 1. The bending strength of the obtained silicon nitride sintered body was measured at room temperature and 1400 ° C. in the same manner as in Example 1, and the results are shown in Table 2.

【００４８】比較例５ 不融化処理の条件以外は実施例１と同じ方法で行った。
不融化処理は、炉内温度４０℃、湿度９０％の雰囲気で
６４時間行った。得られたセラミックファイバーの元素
分析を行い、元素Ｓｉ、Ｎ、Ｃ及びＯの含有率を表１に
示す。得られた窒化珪素焼結体も実施例１と同様に室温
及び１４００℃での曲げ強度を測定し、結果を表２に示
す。また、焼成したセラミックスマトリックス中のファ
イバーの電子顕微鏡写真を図３に示す。 Comparative Example 5 The same method as in Example 1 was carried out except for the condition of infusibilizing treatment.
The infusibilizing treatment was carried out for 64 hours in an atmosphere having a furnace temperature of 40 ° C. and a humidity of 90%. The elemental analysis of the obtained ceramic fiber was performed, and the content rates of the elements Si, N, C and O are shown in Table 1. The bending strength of the obtained silicon nitride sintered body was measured at room temperature and 1400 ° C. in the same manner as in Example 1, and the results are shown in Table 2. An electron micrograph of the fibers in the fired ceramic matrix is shown in FIG.

【００４９】比較例６ 熱分解処理の雰囲気ガス以外は実施例１と同じ方法で行
った。熱分解処理は水素ガス雰囲気（圧力１ａｔｍ）下
で行った。得られたセラミックファイバーの元素分析を
行い、元素Ｓｉ、Ｎ、Ｃ及びＯの含有率を表１に示す。
得られた窒化珪素焼結体も実施例１と同様に室温及び１
４００℃での曲げ強度を測定し、結果を表２に示す。 Comparative Example 6 The same method as in Example 1 was carried out except for the atmosphere gas for the thermal decomposition treatment. The thermal decomposition treatment was performed under a hydrogen gas atmosphere (pressure 1 atm). The elemental analysis of the obtained ceramic fiber was performed, and the content rates of the elements Si, N, C and O are shown in Table 1.
The obtained silicon nitride sintered body was also subjected to room temperature and 1 as in Example 1.
The bending strength at 400 ° C. was measured, and the results are shown in Table 2.

【００５０】表１ セラミックファイバーの元素分析 元素含有率（重量％）Ｎｏ． Si O N C 実施例１ 58.6 2.8 39.2 0.8 比較例１ 50.6 17 17 16 比較例２ 51.2 11 20 16 比較例３ 56 16 22 7.6 比較例４ 54.7 22 16 4.6 比較例５ 44.7 29 22 0.3 比較例６ 57.3 29.8 2.6 9.8 Table 1 Elemental analysis of ceramic fiber Element content (% by weight) No. Si ONC Example 1 58.6 2.8 39.2 0.8 Comparative Example 1 50.6 17 17 16 Comparative Example 2 51.2 11 20 16 Comparative Example 3 56 16 22 7.6 Comparative Example 4 54.7 22 16 4.6 Comparative Example 5 44.7 29 22 0.3 Comparative Example 6 57.3 29.8 2.6 9.8

【００５１】表２ セラミック焼結体の曲げ強度 曲げ強度（ＭＰａ）Ｎｏ． 室温 １４００℃ 実施例１ 508 553 比較例１ 420 425 比較例２ 432 430 比較例３ 438 440 比較例４ 427 432 比較例５ 220 380比較例６ 481 479 Table 2 Bending Strength of Ceramic Sintered Body Bending Strength (MPa) No. Room temperature 1400 ° C. Example 1 508 553 Comparative Example 1 420 425 Comparative Example 2 432 430 Comparative Example 3 438 440 Comparative Example 4 427 432 Comparative Example 5 220 380 Comparative Example 6 481 479

【００５２】表１から分かるように、実施例１で得られ
たセラミックファイバーの元素ＣとＯの合計含有量は１
０重量％以下であり、元素Ｃと元素Ｏの含有量の比が
０．２９であった。それに対して、比較例１〜６で得ら
れたセラミックファイバーの元素ＣとＯの合計含有量は
いずれも１０重量％以上であった。その結果、表２から
明らかなように、実施例１の焼結体の曲げ強度が比較例
１〜６のどれよりも優れている。As can be seen from Table 1, the total content of the elements C and O of the ceramic fiber obtained in Example 1 is 1
It was 0% by weight or less, and the ratio of the contents of the element C and the element O was 0.29. On the other hand, the total content of elements C and O in the ceramic fibers obtained in Comparative Examples 1 to 6 was 10% by weight or more. As a result, as is clear from Table 2, the bending strength of the sintered body of Example 1 is superior to any of Comparative Examples 1 to 6.

【００５３】また、図１から分かるように、実施例１の
焼結体では、マトリックスとファイバーの間に空隙がな
く、均一な組織になっているため、機械的強度が低下し
ない。しかし、比較例１の焼結体では、図２に示すよう
にファイバーが消失して欠陥となり、また比較例５の焼
結体では図３に示すようにファイバーの残留物とマトリ
ックスとの間に空隙が存在し、焼結体の強度を低減させ
る原因となる。Further, as can be seen from FIG. 1, the sintered body of Example 1 has no void between the matrix and the fiber and has a uniform structure, so that the mechanical strength does not decrease. However, in the sintered body of Comparative Example 1, the fibers disappeared as shown in FIG. 2 and became defective, and in the sintered body of Comparative Example 5, as shown in FIG. 3, between the fiber residue and the matrix. The presence of voids causes the strength of the sintered body to be reduced.

【００５４】[0054]

【発明の効果】上記の通り、本発明のセラミック成形体
の強化方法によれば、酸素と炭素の含有量を抑えたセラ
ミックファイバーを添加することにより、セラミック成
形体を強化するとともに、焼結に伴うセラミックスの機
械的強度の低減をなくし、高い機械的強度を有する焼結
体を得ることができる。As described above, according to the method for strengthening a ceramic molded body of the present invention, it is possible to strengthen the ceramic molded body and to sinter the ceramic molded body by adding a ceramic fiber having a reduced oxygen and carbon content. It is possible to eliminate the accompanying reduction in mechanical strength of ceramics and obtain a sintered body having high mechanical strength.

【００５５】本発明の方法から得られた焼結体は、良好
な機械的強度及び耐熱性を有し、ターボチャージャのロ
ータブレードのような自動車部品等に使用するのに適す
る。The sintered body obtained by the method of the present invention has good mechanical strength and heat resistance and is suitable for use in automobile parts such as rotor blades of turbochargers.

【図面の簡単な説明】[Brief description of drawings]

【図１】実施例１において得られたセラミック焼結体の
電子顕微鏡写真である。FIG. 1 is an electron micrograph of a ceramic sintered body obtained in Example 1.

【図２】比較例１において得られたセラミック焼結体の
電子顕微鏡写真である（倍率２０００）。FIG. 2 is an electron micrograph of a ceramic sintered body obtained in Comparative Example 1 (magnification: 2000).

【図３】比較例５において得られたセラミック焼結体の
電子顕微鏡写真である（倍率２０００）。FIG. 3 is an electron micrograph of a ceramic sintered body obtained in Comparative Example 5 (magnification: 2000).

─────────────────────────────────────────────────────
─────────────────────────────────────────────────── ───

【手続補正書】[Procedure amendment]

【提出日】平成７年２月２３日[Submission date] February 23, 1995

【手続補正１】[Procedure Amendment 1]

【補正対象書類名】明細書[Document name to be amended] Statement

【補正対象項目名】００２４[Name of item to be corrected] 0024

【補正方法】変更[Correction method] Change

【補正内容】[Correction content]

【００２４】なお、セラミック成形体に用いるセラミッ
クファイバーは平均直径が２０μｍ以下、特に３〜１０
μｍ、繊維長は１０〜６００μｍ、特に１００〜３００
μｍに調整することが望ましい。平均直径及びファイバ
ー長が大きくなりすぎると分散性が低下し、焼結後の成
形品に欠陥が生じるおそれが大きく、また焼結密度が低
下する。一方、平均直径やファイバー長が小さすぎる
と、セラミックファイバーの添加による補強効果が十分
に得られない。The ceramic fiber used for the ceramic molded body has an average diameter of 20 μm or less, particularly 3 to 10
[mu] m, fiber length. 10 to 600 [mu] m, in particular 100 to 300
It is desirable to adjust to μm. If the average diameter and the fiber length are too large, the dispersibility decreases, the molded product after sintering is likely to have defects, and the sintered density decreases. On the other hand, if the average diameter or the fiber length is too small, the reinforcing effect due to the addition of the ceramic fiber cannot be sufficiently obtained.

Claims (3)

【特許請求の範囲】[Claims] 【請求項１】 マトリックスとなるセラミック成分にフ
ァイバー形態のセラミック成分を添加してセラミック成
形体を強化する方法において、前記ファイバーの必須成
分をＳｉ及びＮとし、元素Ｏ及びＣの合計含有量を１０
重量％以下にし、かつ元素Ｃの含有量と元素Ｏの含有量
との比を０．０８〜２にすることを特徴とするセラミッ
ク成形体の強化方法。1. A method of strengthening a ceramic molded body by adding a fiber-form ceramic component to a matrix ceramic component, wherein Si and N are essential components of the fiber, and a total content of elements O and C is 10.
A method for strengthening a ceramic molded body, characterized in that the content of the element C and the content of the element O are set to 0.08 to 2 by weight or less. 【請求項２】 請求項１に記載のセラミック成形体の強
化方法において、前記ファイバー中の元素Ｏの含有量と
前記マトリックス中の元素Ｏの含有量との比を６以下に
することを特徴とするセラミック成形体の強化方法。2. The method for strengthening a ceramic molded body according to claim 1, wherein the ratio of the content of the element O in the fiber to the content of the element O in the matrix is 6 or less. A method for strengthening a ceramic molded body. 【請求項３】 請求項１又は２に記載のセラミック成形
体の強化方法において、前記ファイバー中の元素Ｓｉの
含有量と前記マトリックス中の元素Ｓｉの含有量との比
を０．８以上、前記ファイバー中の元素Ｎの含有量と前
記マトリックス中の元素Ｎの含有量との比を０．６以上
にすることを特徴とするセラミック成形体の強化方法。3. The method for strengthening a ceramic molded body according to claim 1, wherein the ratio of the content of elemental Si in the fiber to the content of elemental Si in the matrix is 0.8 or more, A method for strengthening a ceramic molded body, wherein the ratio of the content of the element N in the fiber to the content of the element N in the matrix is set to 0.6 or more.
JP6026142A 1994-01-28 1994-01-28 Method for reinforcing ceramic compact Pending JPH07215774A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
JP6026142A JPH07215774A (en) 1994-01-28 1994-01-28 Method for reinforcing ceramic compact
DE1995102385 DE19502385C2 (en) 1994-01-28 1995-01-26 Process for reinforcing ceramic shaped bodies and reinforced ceramic shaped bodies
US08/877,953 US5856253A (en) 1994-01-28 1997-06-17 Method of reinforcing molded body of ceramic and reinforced mold body of ceramic

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP6026142A JPH07215774A (en) 1994-01-28 1994-01-28 Method for reinforcing ceramic compact

Publications (1)

Publication Number Publication Date
JPH07215774A true JPH07215774A (en) 1995-08-15

Family

ID=12185301

Family Applications (1)

Application Number Title Priority Date Filing Date
JP6026142A Pending JPH07215774A (en) 1994-01-28 1994-01-28 Method for reinforcing ceramic compact

Country Status (2)

Country Link
JP (1) JPH07215774A (en)
DE (1) DE19502385C2 (en)

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* Cited by examiner, † Cited by third party
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CN110894155A (en) * 2018-09-12 2020-03-20 揖斐电株式会社 Method for manufacturing honeycomb structure
CN115893985A (en) * 2022-12-19 2023-04-04 齐鲁工业大学 Light high-temperature-resistant ceramic material suitable for ceramic painting based on yellow river mud and preparation method thereof

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008222469A (en) * 2007-03-09 2008-09-25 Ngk Insulators Ltd Silicon nitride sintered compact and its manufacturing method

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5151390A (en) * 1986-06-13 1992-09-29 Toa Nenryo Kogyo Kabushiki Kaisha Silicon nitride-based fibers and composite material reinforced with fibers

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110894155A (en) * 2018-09-12 2020-03-20 揖斐电株式会社 Method for manufacturing honeycomb structure
US11511458B2 (en) 2018-09-12 2022-11-29 Ibiden Co., Ltd. Method of producing honeycomb structured body
CN115893985A (en) * 2022-12-19 2023-04-04 齐鲁工业大学 Light high-temperature-resistant ceramic material suitable for ceramic painting based on yellow river mud and preparation method thereof
CN115893985B (en) * 2022-12-19 2024-01-23 齐鲁工业大学 Light high-temperature-resistant ceramic material suitable for ceramic painting based on yellow river mud and preparation method thereof

Also Published As

Publication number Publication date
DE19502385A1 (en) 1995-08-03
DE19502385C2 (en) 1997-05-22

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