JPS59152271A - Manufacture of high density silicon nitride reaction sintered body - Google Patents

Abstract

(57)【要約】本公報は電子出願前の出願データであるた
め要約のデータは記録されません。(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

【発明の詳細な説明】 本発明は窒化珪素反応焼結体の高密度のものを製造する
方法に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a high density silicon nitride reaction sintered body.

窒化珪素Ｓｉ３Ｎ４の製品のうち、反応焼結体とよばれ
るものは、ふつう、Ｓ１粉末の成形体または（Ｓｉ　＋
Ｓｉ　３Ｎ４）粉末混合物の成形体に窒素ガスを作用さ
せて窒化しつつ焼結することにより製造されている。　
この種の製品は、耐熱衝撃性、硬度、高温での電気絶縁
性および化学的安定性にすぐれているうえ、反応焼結時
の収縮がほとんどなく、寸法積石が高く得られるという
利点があるため、耐火材料、耐摩耗材料、耐食材料、絶
縁材料などの用途に広く使用されている。Among products of silicon nitride Si3N4, those called reaction sintered bodies are usually compacted bodies of S1 powder or (Si +
It is manufactured by sintering a molded body of Si3N4) powder mixture while nitriding it by applying nitrogen gas.
This type of product has excellent thermal shock resistance, hardness, electrical insulation properties at high temperatures, and chemical stability, and has the advantage of having almost no shrinkage during reaction sintering, making it possible to obtain high-dimension stone. Therefore, it is widely used in applications such as fireproof materials, wear-resistant materials, corrosion-resistant materials, and insulation materials.

従来の窒１ヒ珪素反応響結体の欠点は機械的に弱いこと
であって、曲げ強度は２０　Ｋ　（Ｉｆ／　ｍｍ２程度
、高くても３０　Ｋ（ｌ　ｆ　／ｍｍ！止まりであり、
耐熱構造用材料としては不満足なことである。　これは
、珪素を完全に窒化して得た製品でも、２０〜３０％の
気孔率をもつ比較的低密度の焼結体でしかないことが原
因である。　より高密度の反応焼結体を製造できれば、
常温から高温にわたって強度を特徴とする特性を改善で
きるから、高温でも強度が低下しないという特徴を生か
して、耐熱構造用材料としてきわめて有用なものとなる
。The drawback of the conventional nitride-silicon reaction composite is that it is mechanically weak, with a bending strength of about 20 K (If/mm2), and at most 30 K (lf/mm!).
This is unsatisfactory as a heat-resistant structural material. This is because even a product obtained by completely nitriding silicon is a sintered body with a relatively low density and a porosity of 20 to 30%. If we can produce a reaction sintered body with higher density,
Since properties characterized by strength can be improved from room temperature to high temperatures, the property of not decreasing strength even at high temperatures makes it extremely useful as a material for heat-resistant structures.

反応焼結体の密度を向上させるためにこれまでとられた
対策は、Ｓｉ　　（または３ｉ　＋ｓｉ　ｓ　Ｎ４）成
形体の密度を高めることである。　具体的には、まず粉
末成形圧力の増大であるが、実用できる限度で高い圧力
を加えても、窒化後の製品の密度は、せいぜい２．３９
（１１０ｍ３（理論密度の７５％）でしかない。　粉末
の粒度を調節して種々の粒径のものを配合することも試
みられたが、それでも反応焼結体の密度は２．５４０１
０ｍ３が限界とされていた。゛ さらに高密度の反応焼結体を得る目的で、Ｓｉ成形体の
予備焼結、すなわち窒化に先立つ不活性雰囲気中での焼
結を導入して、Ｓ１成形体の高密度の焼結体をつくるこ
とが提案された（特開昭５２−１２１６１３号）。The measures taken so far to improve the density of reaction sintered bodies are to increase the density of Si (or 3i + s s N4) compacts. Specifically, the first step is to increase the powder compaction pressure, but even if a high pressure is applied to the practical limit, the density of the product after nitriding will be 2.39 at most.
(It is only 110 m3 (75% of the theoretical density). Attempts have been made to adjust the particle size of the powder and mix different particle sizes, but the density of the reaction sintered body is still 2.5401.
The limit was 0m3.゛In order to obtain a reaction sintered body with even higher density, we introduced preliminary sintering of the Si compact, that is, sintering in an inert atmosphere prior to nitriding, to obtain a high-density sintered compact of the S1 compact. It was proposed to create one (Japanese Unexamined Patent Publication No. 121613/1982).

しかし、上記開示の方法は、予備焼結による５− ３ｉ成形体の高密度を実効あるものとするために、平均
粒径０．２μ以下というきわめて微細なＳ１粉末を使用
することを必須条件とする。　そのＪ：うな微粉末の製
造が容易でないという問題は別にしても、得られる反応
焼結体の密度は、なお、２、３９（１／Ｃｌ１１３　（
理論密度の９２％）　カ限１１テあった。However, the method disclosed above requires the use of extremely fine S1 powder with an average particle size of 0.2μ or less in order to effectively achieve high density of the 5-3i molded body by preliminary sintering. do. Part J: Apart from the problem that it is not easy to produce eel fine powder, the density of the obtained reaction sintered body is 2.39 (1/Cl113 (
92% of the theoretical density) The limit was 11 te.

本発明者は、予備焼結を利用するＳｉ成形体の高密度化
をさらにおし進めることを意図して協働者とともに研究
を重ね、最高３．０５ａ／ｃｍ３（理論密度の９６％）
に達するきわめて高密度の反応焼結体を得ることに成功
し、すでに開示した（特開昭５７−１８８４６５号およ
び５７−１８８４６６号）。The present inventor has conducted repeated research with collaborators with the intention of further increasing the density of Si molded bodies using pre-sintering, and has achieved a maximum density of 3.05a/cm3 (96% of the theoretical density).
We succeeded in obtaining a reaction sintered body with an extremely high density reaching 100 mL, which has already been disclosed (Japanese Patent Laid-open Nos. 57-188465 and 57-188466).

さきの開示で述べたように、微細なＳｉ粉末を用いて成
形体をつくり、それを予備焼結して窒化する反応焼結体
の製造において到達し得る密度に上記の限界があるのは
、予備焼結体の窒化の速度が遅く、かつその進行がある
程度で飽和してしまい、長時間にわたる加熱を続けても
、かなりの量６− の３ｉが未反応のまま残留するからである。　さぎの発
明では、特定の元素、すなわちＢおよび（または）、ｌ
Ｔｅ、Ｃ０１Ｎｉ　、Ｃｒ、Ｍｏ、Ｍｎ　％　Ｗ、Ｔｉ
　、７ｒ　、Ｔａ　、Ｎｂ　、Ｖ、Ｍ（＋、Ｃａ　、Ｃ
Ｉ＋　、７ｎおよびＳｎからえらんだ１種または２種以
上の元素またはその化合物を一定量加えて、窒化を促進
することによりこの問題を解決した。As mentioned in the previous disclosure, the reason for the above-mentioned limit in the density that can be achieved in the production of reaction sintered bodies by making a compact using fine Si powder, pre-sintering it, and nitriding it is because This is because the rate of nitriding of the preliminary sintered body is slow, and the progress reaches saturation after a certain point, so that even if heating is continued for a long time, a considerable amount of 6-3i remains unreacted. In Sagi's invention, certain elements, namely B and/or, l
Te, C01Ni, Cr, Mo, Mn% W, Ti
,7r,Ta,Nb,V,M(+,Ca,C
This problem was solved by adding a certain amount of one or more elements selected from I+, 7n, and Sn or their compounds to promote nitridation.

上記の方法の実施に当ってさらに実験を重ねたところ、
最良の結果を得るためには、予備焼結のための加熱に際
しての昇温速度が重要であることを見出して本発明に至
った。After further experiments in implementing the above method, we found that
The present invention was developed based on the discovery that the rate of temperature increase during heating for pre-sintering is important in order to obtain the best results.

すなわち、本発明の高密度窒化珪素反応焼結体を製造す
る方法の第一の態様は、ホウ素またはその化合物をＢと
して０．１５〜５．０ｆｉｆｆｉ％含有する珪素粉末を
成形し、成形体を１，１００℃以上であって珪素の融点
よりは低い温度まで１０℃／ｍｉｎ以上の昇温速度で加
熱して予備焼結し、得られた珪素の予備焼結体に、１，
１００〜１，５００℃の温度において窒素を作用させて
窒化することからなる。That is, the first aspect of the method for producing a high-density silicon nitride reaction sintered body of the present invention is to mold silicon powder containing 0.15 to 5.0 fiffi% of boron or its compound as B, and to form a molded body. Pre-sintered by heating to a temperature of 1,100° C. or higher but lower than the melting point of silicon at a temperature increase rate of 10° C./min or higher, and to the obtained silicon pre-sintered body, 1,
It consists of nitriding by applying nitrogen at a temperature of 100 to 1,500°C.

また、本発明の高密度窒化珪素反応焼結体を製造する方
法の第二の態様は、Ｆｅ１Ｃｏ、Ｎｉ。A second aspect of the method for producing a high-density silicon nitride reaction sintered body of the present invention is Fe1Co, Ni.

Ｃｒ　、Ｍｏ　、Ｍｎ　、Ｗ、Ｔｉ　、Ｚｒ　、Ｔａ　
、　Ｎｈ　。Cr, Mo, Mn, W, Ti, Zr, Ta
, Nh.

■、ＭＯ、Ｃａ　、Ｃｕ　、Ｚｎおよび３ｎからえらん
だ１種または２種以上の元素またはその化合物を上記元
素として（２種以上の場合は合計量で）０．０５〜０．
８５重和気含右する珪素粉末を成形し、成形体を１，１
００℃以上であって珪素の融点よりは低い温度まで１０
℃／ｍｉｎ以上の昇温速度で加熱して予備焼結し、得ら
れた珪素の予備焼結体に１．１００〜１．５００℃の温
度において窒素を作用させて窒化することからなる。(2) One or more elements selected from MO, Ca, Cu, Zn, and 3n, or their compounds, as the above elements (in the case of two or more, the total amount) is 0.05 to 0.
Silicon powder containing 85% hydrogen is molded, and the molded product is 1,1
10 to a temperature of 00°C or higher but lower than the melting point of silicon.
The method consists of pre-sintering by heating at a temperature increase rate of .degree. C./min or more, and nitriding the obtained silicon pre-sintered body by applying nitrogen at a temperature of 1.100 to 1.500.degree.

さらに、本発明の高密度窒化珪素反応焼結体を製造する
方法の第三の、そして好ましい態様は、Ｆｅ　１Ｇｏ　
−Ｎ＋　１Ｃｒ　−ＭＯ、Ｍｎ　−ＷｌＴｉ　ＮＺｒ　
、Ｔａ　、Ｎｂ　ＳＶＳＭａ　、Ｃａ　、Ｃｕ　、Ｚｎ
および３ｎからえらんだ１種または２種以上の元素また
はその化合物を上記元素として（２種以上の場合は合計
量で）０．０５〜０．８５重量％、ならびにホウ素また
はその化合物をＢとして０゜１５〜５．０重量％含有す
る珪素粉末を成形し、成形体を１．１００℃以上であ・
つて珪素の融点よりは低い温度まで１０℃／ｍｉｎ以上
の昇温速度で加熱して予備焼結し、得られた珪素の予備
焼結体に１．１００〜１，５００℃の温度において窒素
を作用させて窒化することからなる。Furthermore, a third and preferred embodiment of the method for producing a high-density silicon nitride reaction sintered body of the present invention is
-N+ 1Cr -MO, Mn -WlTi NZr
, Ta, Nb SVSMa, Ca, Cu, Zn
and 0.05 to 0.85% by weight of one or more elements selected from 3n or their compounds (in the case of two or more, the total amount) as the above elements, and 0% of boron or its compounds as B. A silicon powder containing 15 to 5.0% by weight is molded, and the molded body is heated to 1.100°C or higher.
The silicon is then pre-sintered by heating to a temperature lower than the melting point of silicon at a heating rate of 10°C/min or more, and the resulting silicon pre-sintered body is heated with nitrogen at a temperature of 1.100 to 1,500°C. The process consists of nitriding.

予備焼結に至るまでの間の、１０℃／ｍｉｎ以上の昇温
速度は、予備焼結体の密度を高くする上で肝要であって
、この条件がみたされないと、後記する例にみるとおり
、高密度の予備焼結体が得られず、従って高密度の反応
焼結体を製造するという目的も達成できない。A temperature increase rate of 10°C/min or more until pre-sintering is essential for increasing the density of the pre-sintered body, and if this condition is not met, as shown in the example below, , a high-density pre-sintered body cannot be obtained, and therefore the purpose of producing a high-density reactive sintered body cannot be achieved.

珪素粉末の成形体の焼結過程でこのような挙動がみられ
る理由は、本発明者も十分理解するに至っていない。　
一般に金属粉末の焼結においては、加熱時の昇温速度は
低い方が好結果を与えるというのが常識であるから、本
発明者の得た知見は、この常識から推測されるところに
反応している。The inventor of the present invention has not fully understood the reason why such behavior is observed during the sintering process of a molded body of silicon powder.
In general, when sintering metal powder, it is common knowledge that a lower temperature increase rate during heating gives better results. ing.

ゆるやかなｌｔａは、その間に珪素の結晶粒の成長９− をもたらし、微細粒子を使用した意味をなくすのが一因
かとも思われる。　ふつうの金属では焼結中またはその
前の加熱中に粒が成長しても焼結性にはあまり悪影響が
ないのに対し、結合様式の異なる珪素は粒成長の影響が
著しいようである。One reason may be that the gradual lta causes the growth of silicon crystal grains during this period, making the use of fine grains meaningless. For ordinary metals, even if grains grow during sintering or during heating prior to sintering, the sinterability is not significantly affected, whereas silicon, which has a different bonding style, seems to be significantly affected by grain growth.

窒化促進結果をもつ前記諸物質の含有量の限界とその理
由は、さきに開示の発明と同じである。The limits and reasons for the contents of the substances that promote nitriding are the same as those of the previously disclosed invention.

すなわち、ホウ素の効果を期待するためには、少なくと
も０．１５重量％の含有を必要とする。That is, in order to expect the effect of boron, it is necessary to contain at least 0.15% by weight.

しかしホウ素は窒化工程において窒化硼素ＢＮを生成し
、これが多量になると反応焼結を阻害する。However, boron generates boron nitride BN in the nitriding process, and when it becomes large, it inhibits reaction sintering.

そのため、５．０１量％以内に止めなければならない。Therefore, it must be kept within 5.01% by weight.

Ｆｅその伯の物質の含有量は、Ｓｉ粉末に対し０．０５
重半％以上ないと効果が得られない。The content of Fe and other substances is 0.05 to Si powder.
No effect can be obtained unless it is more than half a percent.

この下限未満では予備焼結体の密度が高くなることもあ
って、Ｓｉを高度に窒化するのに要する時間が、実用的
といえないほど長くなる。　一方、０．８５％を超える
含有は、著しい粒成長を招き、予備焼結における高密度
化を妨げるので、避けな１０− ければならない。　好ましい範囲は使用元素により異な
るが、ふつう０．１〜０．６重量％である。If it is less than this lower limit, the density of the pre-sintered body may become high, and the time required to nitridize Si to a high degree becomes impractically long. On the other hand, a content of more than 0.85% must be avoided because it causes significant grain growth and prevents high density during preliminary sintering. The preferred range varies depending on the element used, but is usually 0.1 to 0.6% by weight.

存在形態は、ホウ素の場合、金属ホウ素、非晶質物、ま
たは金属ホウ化物などのいずれであってもよく、Ｆｅそ
の他は、元素状態であっても、また酸化物などの化合物
であってもよく、それら同士の化合物は、もちろん好ま
しいものである。In the case of boron, the existing form may be metal boron, an amorphous substance, or a metal boride, and Fe and others may be in an elemental state or in a compound such as an oxide. , compounds among them are of course preferred.

両者を併用する場合は、ホウ素とこれら元素との化合物
をえらべば、両者を一挙に存在させることができて好ま
しい。When both are used together, it is preferable to select a compound of boron and these elements because both can be present at once.

原料のＳｉ粉末は、予備焼結における高密度化を容易に
するために、平均粒径が１５μ以下のものを使用すべぎ
であって、望ましいのは１μ以下の微粉末である。The raw material Si powder should have an average particle size of 15 μm or less, and preferably a fine powder of 1 μm or less in order to facilitate high density during preliminary sintering.

窒化促進剤の諸物質およびホウ素またはその化合物も、
３ｉ粉末の粒度と同等またはそれ以下の微粒子であるこ
とが望ましい。Nitriding accelerator substances and boron or its compounds,
It is desirable that the particles have a particle size equal to or smaller than that of the 3i powder.

粉末成形おにび予備焼結に関する技術は、さきに開示し
たところと変らない。　すなわち、原料粉末または粉末
混合物の成形は、常用のダイス成形をはじめとして、等
方圧成形、スリップキャスト、射出成形など任意の手段
によることができるのはもちろんである。The technology for powder compaction and pre-sintering is the same as previously disclosed. That is, it goes without saying that the raw material powder or powder mixture can be molded by any means such as conventional die molding, isostatic pressing, slip casting, injection molding, and the like.

予備焼結する成形体の密度は、その取り扱いや加工を容
易にするとともに、予備焼結における焼結性を確保する
ために、０．８２０　／ｃｍ３　（理論密度の３５％）
以上にすべきである。　これより低い密度では、予備焼
結により高密度化できても、均一な組織を有する焼結体
を得ることが困難となる。The density of the compact to be pre-sintered is 0.820/cm3 (35% of the theoretical density) in order to facilitate its handling and processing and to ensure sinterability during pre-sintering.
It should be more than that. If the density is lower than this, it is difficult to obtain a sintered body having a uniform structure even if the density can be increased by preliminary sintering.

予備焼結の方法は、自由焼結のほか、−軸加圧焼結（い
わゆるホットプレス）、熱間等方圧焼結などの通常の方
法をとることができる。In addition to free sintering, the preliminary sintering can be carried out by conventional methods such as -axis pressure sintering (so-called hot press) and hot isostatic pressure sintering.

予備焼結は、１．１００℃以上の温度において行なう。Pre-sintering is performed at a temperature of 1.100°C or higher.

　これより低い温度では、微細な粉末を使用しても高密
度化が期待できない。　上限の温度は、もちろん３ｉの
融点である。　雰囲気はアルゴンのような不活性ガスが
好適であるが、真空であってもよい。At temperatures lower than this, high density cannot be expected even if fine powder is used. The upper temperature limit is of course the melting point of 3i. The atmosphere is preferably an inert gas such as argon, but may also be a vacuum.

予備焼結の段階での高密度化の程度は、焼結に伴う収縮
量であられされる。　これは焼結する成形体の密度によ
っても同じではないが、本発明で実現しようとする高密
度反応焼結製品を与えるには、体積収縮率にして、少な
くとも１０％必要であり、２０％以上あることが好まし
い。The degree of densification at the preliminary sintering stage is determined by the amount of shrinkage caused by sintering. This does not depend on the density of the compact to be sintered, but in order to provide the high-density reaction sintered product that the present invention aims to achieve, the volumetric shrinkage rate must be at least 10%, and 20% or more. It is preferable that there be.

予備焼結体のもつ密度は、原料粉末の粒度、成形条件お
よび焼結条件により大きく異なるが、反応焼結体に得ら
れる密度および窒化の容易さの点からみて、１．３７〜
２．１０ｏ／ｃ誦３の範囲内になるよう予備焼結を行な
うべきである。The density of the preliminary sintered body varies greatly depending on the particle size of the raw material powder, molding conditions, and sintering conditions, but from the viewpoint of the density obtained in the reaction sintered body and the ease of nitriding, it is 1.37 to 1.37.
2. Pre-sintering should be performed to within the range of 10 o/c.

Ｓｉ予備焼結体の窒化は、本発明においても、従来の窒
化珪素反応焼結体の製造に際して行なわれていたところ
と同じようにして実施できる。In the present invention, the Si pre-sintered body can be nitrided in the same manner as in the production of conventional silicon nitride reaction sintered bodies.

すなわち、一般的には大気圧の窒素ガス雰囲気下で、１
．１００〜１．５００℃の温度に加熱する。That is, in general, under a nitrogen gas atmosphere at atmospheric pressure, 1
．． Heat to a temperature of 100-1.500°C.

温度は、１，１００〜１．３５０℃の低温側から段階的
に昇温してゆくこともできる。　反応速度をｌ！節する
ためには、窒素の圧力を減圧（最大１００分の１気圧程
度まで）から加圧（最高２．０００気圧）までの範囲で
選択すればよい。The temperature can also be increased stepwise from a low temperature of 1,100 to 1.350°C. The reaction rate is l! In order to reduce the pressure, the nitrogen pressure may be selected from a reduced pressure (up to about 1/100 atm) to an increased pressure (up to 2,000 atm).

１３− なお、純窒素ガスのほかにも、水素混合窒素ガスやアン
モニアも使用できる。13- In addition to pure nitrogen gas, hydrogen-mixed nitrogen gas and ammonia can also be used.

窒化に要する時間は、予備焼結体の密度、平均粒径、窒
化温度および雰囲気条件により、また許容できる残留３
ｉ吊により大きく異なるが、数時間から２００時間程痕
である。The time required for nitriding depends on the density of the presintered body, average grain size, nitriding temperature, and atmospheric conditions, as well as the allowable residual 3
Although it varies greatly depending on the hanging time, the marks last from several hours to 200 hours.

次に示す実施例にみるとおり、本発明の方法によれば、
未窒化残留Ｓｉｌを実際上好ましい許容限度である０、
５重量％以下におさえて最高３゜０５０／ｃ＋＋＋３（
理論密度の９６％）の高密度をもつ反応焼結体が製造で
きる。As shown in the following examples, according to the method of the present invention,
The unnitrided residual Sil is set to 0, which is a practically preferable allowable limit.
Maximum 3゜050/c+++3(
A reaction sintered body having a high density (96% of the theoretical density) can be produced.

実施例１ 平均粒径０．１８μの３ｉ粉末に、非晶質のホウ素０．
４重量％を添加して、ポリエチレン被覆を施したボール
ミル中で湿式法により十分に混合した。Example 1 3i powder with an average particle size of 0.18μ was added with 0.0% of amorphous boron.
4% by weight was added and thoroughly mixed by wet method in a polyethylene coated ball mill.

この粉末混合物をステンレス製ダイスを用いて、直径１
５ｍｍｘ高さ１０ＩＩＩＩｌの円柱状態に成形した。This powder mixture was diced using a stainless steel die with a diameter of 1 mm.
It was molded into a cylindrical shape measuring 5 mm x 10IIIl in height.

成形体の密度は理論密度の５０％であった。The density of the compact was 50% of the theoretical density.

成形体を１気圧のアルゴン雰囲気下に１，３５０１４− ℃まで２０℃／ｍｉｎの昇温速度で加熱し、この温度に
１時間保持する予備焼結をして、理論密度の７８％の密
度の予備焼結体を得た。　この段階における体積収縮は
、３６％である。The compact is pre-sintered by heating it to 1,350-14-℃ at a heating rate of 20℃/min under an argon atmosphere of 1 atm and holding it at this temperature for 1 hour, resulting in a density of 78% of the theoretical density. A preliminary sintered body was obtained. The volumetric shrinkage at this stage is 36%.

上記の予備焼結体を、１気圧の（Ｎ２＋５％１２　）　
ｉｆ　ス雰囲気下テ、１．３４０℃Ｘ３０時間→１．３
８０℃Ｘ９０時間→１，４５０℃Ｘ２０時間の処理によ
り窒化したところ、理論密度の９６％の密度の反応焼結
体を得た。　その中の残留３ｉ量は０．５重量％以下で
あった。The above pre-sintered body was heated to 1 atm (N2+5%12).
If under steam atmosphere, 1.340℃ x 30 hours → 1.3
When nitriding was performed at 80° C. for 90 hours → 1,450° C. for 20 hours, a reaction sintered body having a density of 96% of the theoretical density was obtained. The amount of residual 3i therein was 0.5% by weight or less.

同じ条件で、直径約５０ｍｍｘ厚さ６１の円板状の反応
焼結体を製造した。　常温におけるその三点曲げ強度を
測定したところ、平均７８Ｋ（１／ｍｍ”という、従来
得られなかった高い値が得られた。A disk-shaped reaction sintered body having a diameter of about 50 mm and a thickness of 61 cm was produced under the same conditions. When the three-point bending strength was measured at room temperature, an average of 78K (1/mm'') was obtained, a high value that had not been previously obtained.

実施例２ 実施例１で得た３ｉ粉末成形体を１．３５５℃×１時間
の条件でアルゴン雰囲気下に予備焼結した。昇温速度は
１０℃／ｍｉｎとした。理論密度の６２％の密度の予備
焼結体を得て、実施例１と同じ条件で窒化させた。Example 2 The 3i powder compact obtained in Example 1 was preliminarily sintered at 1.355° C. for 1 hour in an argon atmosphere. The temperature increase rate was 10°C/min. A pre-sintered body having a density of 62% of the theoretical density was obtained and nitrided under the same conditions as in Example 1.

得られた反応焼結体は、密度が理論密度の７６％、残留
Ｓｉ　ｍｏ、５重量％以下で、強度は３３Ｋａｆ／ＩＩ
ＩＩＩ１２テアツタ。The obtained reaction sintered body has a density of 76% of the theoretical density, residual Si mo of 5% by weight or less, and a strength of 33 Kaf/II.
III12 Tea Tsuta.

比較例１および２ 実施例１において、予備焼結体に至る加熱の際の昇温速
度を、それぞれ８℃／ｗｉｎおよび１℃／１ｎとしたほ
かは、同じ条件で予備焼結を行なって、それぞれ理論密
度の５５％および５３％の密度をもつ予備焼結体を得た
。Comparative Examples 1 and 2 Pre-sintering was performed under the same conditions as in Example 1, except that the temperature increase rate during heating to the pre-sintered body was 8°C/win and 1°C/1n, respectively. Pre-sintered bodies with densities of 55% and 53% of the theoretical density were obtained, respectively.

この予備焼結体を実施例１と同じ条件で窒化して、密度
が理論密度に対してそれぞれ６７％および６５％である
反応焼結体を得た。This preliminary sintered body was nitrided under the same conditions as in Example 1 to obtain reaction sintered bodies whose densities were 67% and 65% of the theoretical density, respectively.

その中の残留３ｉはいずれも０．５％以下であったが、
強度はそれぞれ２５　Ｋ　ｏｆ／　ｍｍ２および２１　
Ｋ（Ｉｆ／＋ａｍ２に止まった。The residual 3i in all of them was less than 0.5%,
Intensities are 25 K of/mm2 and 21 respectively
K(If/+am2).

実施例３ 平均粒径３．０μの８１粉末を用いて、実施例１と同様
にして粉末成形体をつくり、予備焼結を行なった。　昇
温速度は２０℃／１ｎ、予備焼結の温度は１．３７０℃
である。Example 3 A powder compact was made in the same manner as in Example 1 using 81 powder with an average particle size of 3.0 μm, and preliminary sintering was performed. Temperature increase rate is 20℃/1n, pre-sintering temperature is 1.370℃
It is.

理論密度の７５％の密度を有する予備焼結体を得、これ
を同じ＜　（Ｎ２　＋５％Ｈ２）ガス雰囲気下に、１．
３４０℃Ｘ４０時間→１．３８０℃×６０時間→１．４
５０℃Ｘ２０時間の加熱条件で窒化した。A pre-sintered body having a density of 75% of the theoretical density was obtained, and this was heated under the same < (N2 + 5% H2) gas atmosphere in 1.
340℃ x 40 hours → 1.380℃ x 60 hours → 1.4
Nitriding was carried out under heating conditions of 50° C. for 20 hours.

理論密度の９２％の密度をもつ反応焼結体が得られた。A reaction sintered body with a density of 92% of the theoretical density was obtained.

　残留Ｓ１は０．５％以下であった。The residual S1 was 0.5% or less.

比較例３ 実施例３において、予備焼結に至る加熱の昇温速度を１
℃／１ｎとしたほかは、同じ条件で予備焼結を行なった
として、予備焼結体の密度は理論密度の５３％であった
。Comparative Example 3 In Example 3, the temperature increase rate for heating leading to preliminary sintering was reduced to 1.
Assuming that preliminary sintering was performed under the same conditions except that the temperature was changed to °C/1n, the density of the preliminary sintered body was 53% of the theoretical density.

これを実施例３と同じ条件で窒化して得た反応焼結体は
、残留Ｓｉは０．５％以下であったが、密度は理論密度
の６５％に止まった。The reaction sintered body obtained by nitriding this under the same conditions as in Example 3 had residual Si of 0.5% or less, but the density remained at 65% of the theoretical density.

実施例４ 実施例１で用いたものと同じ平均粒径０．１８μの３ｉ
粉末に、Ｆｅ２Ｏ３粉末を１重量％添加して実施例１と
同様の条件で粉末成形および予備焼結した。Example 4 3i with the same average particle size of 0.18 μ as used in Example 1
1% by weight of Fe2O3 powder was added to the powder, and the powder was compacted and presintered under the same conditions as in Example 1.

１７− 理論密度の７５％の密度を有する予備焼結体を得、これ
をＮ２ガス雰囲気下に、１．３４０℃×２０時間→１．
３８０℃Ｘ３０時間→１．４５０’ＣＸ２０時間の加熱
条件で窒化した。　理論密度の９２％の密度をもつ反応
焼結体を得た。17- A preliminary sintered body having a density of 75% of the theoretical density was obtained, and this was heated at 1.340°C for 20 hours in a N2 gas atmosphere → 1.
Nitriding was carried out under heating conditions of 380°C x 30 hours → 1.450'C x 20 hours. A reaction sintered body having a density of 92% of the theoretical density was obtained.

比較例４ 実施例４において、予備焼結に至る加熱の昇温速度を１
℃／１ｎとしたほかは同じ条件で予備焼結を行なったと
ころ、予備焼結体の密度は理論密度の５２％であった。Comparative Example 4 In Example 4, the temperature increase rate of heating leading to preliminary sintering was changed to 1.
Preliminary sintering was carried out under the same conditions except that the temperature was 0.degree. C./1n, and the density of the presintered body was 52% of the theoretical density.

これを実施例４と同じ条件で窒化して得た反応焼結体は
、残留Ｓｉは０．５％以下であったが、密度は理論密度
の６３％に止まった。The reaction sintered body obtained by nitriding this under the same conditions as in Example 4 had residual Si of 0.5% or less, but the density remained at 63% of the theoretical density.

実施例５ 実施例１で用いたものと同じ平径粒ｔ￥！０．１８μの
３ｉ粉末に、非晶質のホウ素を０．４重量％、１”ｅ　
２０３粉末を１．０％添加して、実施例１と同じ条件で
粉末成形および予備焼結をした。Example 5 Same flat-diameter grains as used in Example 1 t￥! Add 0.4% by weight of amorphous boron to 0.18μ 3i powder and 1”e
Powder compaction and preliminary sintering were carried out under the same conditions as in Example 1, with the addition of 1.0% of 203 powder.

理論密度の７９％に及ぶ密度を有する予備焼結体を冑、
これを（Ｎ２＋５％１」２）ガス雰囲気下１８− に、１．３４０℃Ｘ４０時間→１．３８０℃×６０時間
→１．４５０℃×２０時間の加熱条件で窒化した。　理
論密度の９６％に達する密度の反応焼結体ができ、その
残留密度は０．５％以下であり、強度は７９　Ｋ　ｌｌ
ｆ／　ｍｍ２であった。A pre-sintered body having a density of 79% of the theoretical density,
This was nitrided under a (N2 + 5% 1''2) gas atmosphere at 18-degree temperature under heating conditions of 1.340°C x 40 hours -> 1.380°C x 60 hours -> 1.450°C x 20 hours. A reaction sintered body with a density reaching 96% of the theoretical density is produced, the residual density is less than 0.5%, and the strength is 79 Kll.
f/mm2.

比較例５ 実施例５において、予備焼結に至る加熱の昇温速痕を１
℃／１ｎとしたほかは同じ条件で予備焼結を行なったと
して、予備焼結体の密度は理論密度の５３％であった。Comparative Example 5 In Example 5, the temperature increase rate trace of heating leading to preliminary sintering was
Assuming that preliminary sintering was performed under the same conditions except that the temperature was set to .degree. C./1n, the density of the preliminary sintered body was 53% of the theoretical density.

これを実施例５と同じ条件で窒化して得た反応焼結体は
、残留Ｓｉは０．５％以下であったが、京成は理論密度
の６５％に止まり、強度は１９Ｋ　Ｑｆ／　ＩＢＩ’　
テＬ／　ｈ’　すｈ’　ツタ。The reaction sintered body obtained by nitriding this under the same conditions as Example 5 had residual Si of 0.5% or less, but Keisei had a density of only 65% of the theoretical density and a strength of 19K Qf/IBI'
teL/h'suh' ivy.

特許出願人　　大同特殊鋼株式会社 代理人　弁理士　　須　賀　総　夫 １９− ３５６−Patent applicant: Daido Steel Co., Ltd. Agent: Patent Attorney: Souo Suga 19- 356-

Claims (6)

【特許請求の範囲】[Claims] （１）ホウ素またはその化合物を８として０．１５〜５
．０重量％含有する珪素粉末を成形し、成形体をｉ、ｉ
ｏｏ℃以上であって珪素の融点よりは低い温度まで１０
℃／ｓｉｎ以上の昇温速度で加熱して予備焼結し、得ら
れた珪素の予備焼結体に１．１００〜１．５００℃の温
度において窒素を作用させて窒化することからなる高密
度窒化珪素反応焼結体を製造する方法。(1) 0.15 to 5 with boron or its compound as 8
．． A silicon powder containing 0% by weight is molded, and the molded body is
10 to a temperature of oo°C or higher but lower than the melting point of silicon.
A high-density product made by pre-sintering by heating at a temperature increase rate of ℃/sin or more, and nitriding the obtained silicon pre-sintered body by applying nitrogen at a temperature of 1.100 to 1.500℃. A method of manufacturing a silicon nitride reaction sintered body. （２）予備焼結時の体積収縮率が１０％以上となるよう
に焼結する特許請求の範囲第１項の方法。(2) The method according to claim 1, in which sintering is performed so that the volumetric shrinkage rate during preliminary sintering is 10% or more. （３）Ｆｅ、Ｃｏ、Ｎｉ５Ｃｒ、ＭＯ，Ｍｎ、Ｗ。 Ｔｉ　、Ｚｒ　、Ｔａ　％Ｎｂ　、Ｖ、ＭＯ、Ｃａ　。 Ｃｕ　、Ｚｎおよび３ｎからえらんだ１種または２種以
上の元素またはその化合物を上記元素として（２種以上
の場合は合計量で）０．０５〜０．８５重量％含有する
珪素粉末を成形し、成形体を１．１００℃以上であって
珪素の融点よりは低い温度まで１０℃／１ｎ以上の昇温
速度で加熱して予備焼結し、得られた珪素の予備焼結体
に１．１００〜１，５００℃の温度において窒素を作用
させて窒化することからなる高密度窒化珪素反応焼結体
を製造する方法。(3) Fe, Co, Ni5Cr, MO, Mn, W. Ti, Zr, Ta%Nb, V, MO, Ca. A silicon powder containing 0.05 to 0.85% by weight of one or more elements selected from Cu, Zn, and 3N or a compound thereof (in the case of two or more elements, the total amount) is molded. The molded body is heated to a temperature of 1.100° C. or higher and lower than the melting point of silicon at a temperature increase rate of 10° C./1n or higher to pre-sinter it, and the obtained silicon pre-sintered body is subjected to 1. A method for producing a high-density silicon nitride reaction sintered body, which comprises nitriding by applying nitrogen at a temperature of 100 to 1,500°C. （４）予備焼結体の体積収縮率が１０％以上となるよう
に焼結する特許請求の範囲第３項の方法。(4) The method according to claim 3, wherein the preliminary sintered body is sintered so that the volume shrinkage rate is 10% or more. （５）ホウ素またはその化合物を８として０．１５〜５
．０重量％、ならびにＦ　ｅ　Ｎ　Ｃｏ　、Ｎ　ｉ　’
−Ｃｒ　、ＭＯ、Ｍｎ　１Ｗ、Ｔｉ　、Ｚｒ　、Ｔａ、
Ｎｂ、Ｖ、Ｍｇ、Ｃａ　、Ｃｕ　、Ｚｎおよびｓｎから
えらんだ１種または２種以上の元素またはその化合物を
上記元素として（２種以上の場合は合計量で）０．０５
〜０．８５重量％含有する珪素粉末を成形し、成形体を
１．１００℃以上であって珪素の融点よりは低い温度ま
で１０℃／ｍｉｎ以上の昇温速度で加熱して予備焼結し
、得られた珪素の予備焼結体に１．１００〜１゜５００
℃の温度において窒素を作用させて窒化することからな
る高密度窒化珪素反応焼結体を製造する方法。(5) 0.15 to 5 with boron or its compound as 8
．． 0% by weight, as well as F e N Co , N i '
-Cr, MO, Mn 1W, Ti, Zr, Ta,
One or more elements selected from Nb, V, Mg, Ca, Cu, Zn, and sn, or their compounds as the above elements (in the case of two or more, the total amount) is 0.05
A silicon powder containing ~0.85% by weight is molded, and the molded body is heated to a temperature of 1.100°C or higher but lower than the melting point of silicon at a temperature increase rate of 10°C/min or more for pre-sintering. , 1.100 to 1°500 to the obtained silicon pre-sintered body
A method for producing a high-density silicon nitride reaction sintered body, which comprises nitriding under the action of nitrogen at a temperature of °C. （６）予備焼結時の体積収縮率が１０％以上となるよう
に焼結する特許請求の範囲第５項の方法。(6) The method according to claim 5, wherein sintering is performed such that the volumetric shrinkage rate during preliminary sintering is 10% or more.