JPH07330440A - Production of sintered compact - Google Patents
Production of sintered compactInfo
- Publication number
- JPH07330440A JPH07330440A JP6148666A JP14866694A JPH07330440A JP H07330440 A JPH07330440 A JP H07330440A JP 6148666 A JP6148666 A JP 6148666A JP 14866694 A JP14866694 A JP 14866694A JP H07330440 A JPH07330440 A JP H07330440A
- Authority
- JP
- Japan
- Prior art keywords
- raw material
- ceramic raw
- sintered body
- heat treatment
- material powder
- 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
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- Compositions Of Oxide Ceramics (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は，セラミック原料粉末の
焼結体の製造方法であって，特に，不純物に基づく異物
の混入や空孔の発生が無く，強度に優れた焼結体の製造
方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a sintered body of ceramic raw material powder, and in particular, the production of a sintered body excellent in strength without inclusion of foreign matter due to impurities or generation of voids. Regarding the method.
【０００２】[0002]
【従来技術】市販のセラミック原料粉末としては，例え
ば，窒化珪素，炭化珪素，窒化アルミニウム，アルミ
ナ，ジルコニア，酸化珪素等がある。かかるセラミック
原料粉末には，一般に，直径数十μｍの金属粉末が０．
０１〜数％混入している。これらの混入物を分析した結
果，金属粉末の主成分は鉄であった。BACKGROUND OF THE INVENTION Commercially available ceramic raw material powders include, for example, silicon nitride, silicon carbide, aluminum nitride, alumina, zirconia, silicon oxide and the like. Generally, metal powder having a diameter of several tens of μm is included in the ceramic raw material powder.
01 to several% are mixed. As a result of analyzing these contaminants, the main component of the metal powder was iron.
【０００３】金属粉末は，セラミック粉末の原料にもと
もと入っていたか，セラミック原料を粉砕する際の粉砕
機の摩耗粉末であると考えられる。従来，セラミック原
料粉末は，上記不純物の混入については特に問題視する
ことなく，そのまま焼結助剤を添加，混合し，媒液中で
通常１μｍ以下に粉砕し，その後成形，焼結を行ってい
た。It is considered that the metal powder was originally contained in the raw material of the ceramic powder, or is considered to be the abrasion powder of the crusher when crushing the ceramic raw material. Conventionally, the ceramic raw material powder has not been particularly concerned about the mixing of the above-mentioned impurities, and a sintering aid is added and mixed as it is, and the powder is usually pulverized to 1 μm or less in a medium, and then molded and sintered. It was
【０００４】[0004]
【解決しようとする課題】しかしながら，セラミック原
料粉末をそのまま用いる場合には，上記不純物の金属粉
末は，延性材料のため粉砕されない。そのため，焼結工
程において，例えば酸化物セラミックスを製造する場合
には，不純物としての鉄が比較的大きな酸化鉄となり，
焼結体中で斑点状の異物として残存する。However, when the ceramic raw material powder is used as it is, the metal powder of the impurities is not pulverized because it is a ductile material. Therefore, in the sintering process, for example, when producing oxide ceramics, iron as an impurity becomes a relatively large iron oxide,
It remains as spotted foreign matter in the sintered body.
【０００５】また，セラミック原料粉末が窒化珪素や炭
化珪素等の非酸化物の場合には，不純物の鉄が焼結工程
で珪素と反応して，比較的大きなケイ化鉄が生成し，こ
のケイ化鉄が焼結体中に異物として残存する。上記のご
とき異物は，焼結体中において大きな粒子として存在す
るため，焼結体の強度が低下する。そのため，金属粉末
を不純物として含むセラミック原料粉末の焼結体は，強
度が低かった。Further, when the ceramic raw material powder is a non-oxide such as silicon nitride or silicon carbide, iron as an impurity reacts with silicon in the sintering process to generate relatively large iron silicide, and Iron oxide remains as a foreign substance in the sintered body. Since the foreign matters as described above exist as large particles in the sintered body, the strength of the sintered body decreases. Therefore, the strength of the sintered body of the ceramic raw material powder containing the metal powder as an impurity was low.
【０００６】そこで，セラミック原料粉末中の不純物
を，磁石により除去することが考えられる。しかし，磁
石による金属粉末の除去では，除去には限界があり，セ
ラミック原料粉末中に金属粉末よりなる不純物が残る。
そのため，上記のようにそれほど焼結体の強度は向上し
ない。Therefore, it is conceivable to remove impurities in the ceramic raw material powder with a magnet. However, there is a limit to the removal of the metal powder with a magnet, and impurities made of the metal powder remain in the ceramic raw material powder.
Therefore, the strength of the sintered body is not so improved as described above.
【０００７】また，不純物除去の他の方法としては，例
えば，不純物が鉄の場合，塩酸溶液中でセラミック原料
粉末を洗浄して，その中の不純物を溶かす方法がある。
しかし，この場合には，その後に，セラミック原料粉末
を水で洗浄して，塩酸溶液を除去し，更に，乾燥する必
要がある。そのため，不純物の除去工程が煩雑となると
共にコスト高となる。本発明はかかる従来の問題点に鑑
み，強度に優れた焼結体の製造方法を提供しようとする
ものである。As another method of removing impurities, for example, when the impurities are iron, there is a method of washing the ceramic raw material powder in a hydrochloric acid solution to dissolve the impurities therein.
However, in this case, after that, it is necessary to wash the ceramic raw material powder with water to remove the hydrochloric acid solution and further to dry it. Therefore, the process of removing impurities becomes complicated and the cost becomes high. In view of the above conventional problems, the present invention aims to provide a method for manufacturing a sintered body having excellent strength.
【０００８】[0008]
【課題の解決手段】本発明は，金属からなる不純物が混
入するセラミック原料粉末を酸化雰囲気中で熱処理を行
い，不純物である金属を酸化物に変化させ，更に該セラ
ミック原料粉末を微粉砕し，次いで成形し，その後該成
形体を加熱，焼結することを特徴とする焼結体の製造方
法にある。According to the present invention, a ceramic raw material powder mixed with impurities made of a metal is heat-treated in an oxidizing atmosphere to change the metal as an impurity into an oxide, and the ceramic raw material powder is further finely pulverized, Next, there is provided a method for producing a sintered body, which comprises molding and then heating and sintering the molded body.
【０００９】本発明において，上記不純物金属として
は，鉄，マンガン，又はクロムなどがある。上記セラミ
ック原料粉末としては，窒化珪素，炭化珪素，窒化アル
ミニウム等の非酸化物，アルミナ，ジルコニア，酸化珪
素等の酸化物がある。In the present invention, the impurity metals include iron, manganese, and chromium. The ceramic raw material powder includes non-oxides such as silicon nitride, silicon carbide and aluminum nitride, and oxides such as alumina, zirconia and silicon oxide.
【００１０】上記熱処理は，大気，又は酸素存在下等の
酸化雰囲気中で行う。具体的には，熱処理は，例えば，
アルミナ等のセラミックス製容器の中に，セラミック原
料を入れて，これを大気炉，又はロータリーキルンで連
続加熱処理を行う。望ましくは，ロータリーキルン等の
ようにセラミック原料粉末を流動させながら熱処理する
のがよい。この場合，セラミック原料粉末の粒子表面が
削れて内部の鉄等の不純物が酸化されやすい。また，熱
処理雰囲気は，大気でも，また積極的に大気を導入して
もよい。更に，酸素過多の雰囲気或いは酸素圧力を高め
た雰囲気でもよい。The above heat treatment is performed in the atmosphere or an oxidizing atmosphere such as in the presence of oxygen. Specifically, the heat treatment is, for example,
A ceramic raw material is placed in a ceramic container such as alumina, and continuously heated in an atmospheric furnace or a rotary kiln. Desirably, heat treatment is performed while flowing the ceramic raw material powder, such as in a rotary kiln. In this case, the particle surface of the ceramic raw material powder is scraped, and impurities such as iron inside are easily oxidized. The heat treatment atmosphere may be the atmosphere, or the atmosphere may be positively introduced. Further, an atmosphere of excess oxygen or an atmosphere of increased oxygen pressure may be used.
【００１１】上記熱処理は，温度５００〜１０００℃で
行うことが好ましい。５００℃未満の場合には，鉄系金
属が酸化しないおそれがある。一方，１０００℃を越え
る場合，非酸化物のセラミック原料粉末では，酸化し，
強度が低下するおそれがある。また，酸化物のセラミッ
ク原料粉末では，セラミック原料粉末同士が焼結し，粒
径が大きくなるおそれがある。The above heat treatment is preferably performed at a temperature of 500 to 1000.degree. If the temperature is lower than 500 ° C, the iron-based metal may not be oxidized. On the other hand, when the temperature exceeds 1000 ° C, the non-oxide ceramic raw material powder oxidizes,
The strength may decrease. Further, in the oxide ceramic raw material powder, the ceramic raw material powders may sinter each other and the particle size may increase.
【００１２】上記熱処理の時間は，０．５〜２０時間で
あることが好ましい。０．５時間未満の場合には，金属
粉末が酸化しないおそれがある。一方，２０時間を越え
る場合，非酸化物のセラミック原料粉末では，酸化さ
れ，強度が低下するおそれがある。また，酸化物のセラ
ミック原料粉末では，セラミック原料粉末同志が焼結
し，粒径が大きくなるおそれがある。The heat treatment time is preferably 0.5 to 20 hours. If it is less than 0.5 hours, the metal powder may not be oxidized. On the other hand, if it exceeds 20 hours, the non-oxide ceramic raw material powder may be oxidized and its strength may be reduced. Further, in the oxide ceramic raw material powder, there is a possibility that the ceramic raw material powders will sinter each other and the particle size will increase.
【００１３】上記熱処理の前において，磁石により鉄等
の磁性材料よりなる不純物を除去することが好ましい。
これにより，金属系の不純物の多くを除去することがで
きる。すなわち，本発明の熱処理の前にある程度の磁性
材料を除去することができ，さらに焼結体の強度が向上
する。特に，３重量％を越える金属粉末が混入している
場合には，熱処理の前に磁石により鉄等の金属粉末をで
きるだけ除去した後，上記酸化雰囲気中で熱処理を行う
ことが好ましい。Before the heat treatment, it is preferable to remove impurities made of a magnetic material such as iron with a magnet.
As a result, most of the metallic impurities can be removed. That is, the magnetic material can be removed to some extent before the heat treatment of the present invention, and the strength of the sintered body is further improved. Particularly, when the metal powder in excess of 3% by weight is mixed, it is preferable to perform the heat treatment in the oxidizing atmosphere after removing the metal powder such as iron as much as possible by the magnet before the heat treatment.
【００１４】上記セラミック原料粉末には，セラミック
原料粉末の焼結を促進するため，焼結助剤を添加混合す
ることが好ましい。なお，焼結助剤がなくても本発明の
目的を達成することができるが，通常上記目的のため焼
結助剤を添加する。焼結助剤としては，ＭｇＯ，Ａｌ2
Ｏ3 ，Ｙ2 Ｏ3 ，ＭｇＡｌ2 Ｏ4 ，ＳｉＯ2 ，Ｂ4 Ｃ，
Ｃ等がある。A sintering aid is preferably added to and mixed with the ceramic raw material powder in order to promote the sintering of the ceramic raw material powder. The object of the present invention can be achieved without a sintering aid, but a sintering aid is usually added for the above purpose. As a sintering aid, MgO, Al 2
O 3 , Y 2 O 3 , MgAl 2 O 4 , SiO 2 , B 4 C,
There is C etc.
【００１５】この焼結助剤が存在すると，さらに焼結体
の強度が向上する。これは以下の理由によると考えられ
る。本発明の熱処理により不純物の金属は酸化鉄のよう
に金属酸化物となる。この金属酸化物は焼結助剤と反応
してガラスとなり，焼結体の粒界を形成する。このよう
な粒界は粒子状のものとは異なり，焼結体の強度に悪影
響を与えることはない。The presence of this sintering aid further improves the strength of the sintered body. This is considered to be due to the following reasons. By the heat treatment of the present invention, the metal as an impurity becomes a metal oxide like iron oxide. This metal oxide reacts with the sintering aid to form glass, which forms the grain boundaries of the sintered body. Such grain boundaries do not adversely affect the strength of the sintered body, unlike the grain boundaries.
【００１６】所望形状への成形は，例えば，金型又はゴ
ム型を用いて，５０〜３００ＭＰａの圧力で金型プレス
法，ラバープレス法，スリップキスト法，射出成形法に
て行なう。上記加熱，焼結は，セラミック原料粉末の成
形体を炉に入れ加熱する。焼結条件は，セラミック原料
が緻密に焼結するように，温度，時間，雰囲気を適宜設
定する。Molding into a desired shape is performed, for example, by using a mold or a rubber mold at a pressure of 50 to 300 MPa by a mold pressing method, a rubber pressing method, a slipkist method, or an injection molding method. In the above heating and sintering, a ceramic raw material powder compact is placed in a furnace and heated. As for the sintering conditions, temperature, time, and atmosphere are appropriately set so that the ceramic raw material is densely sintered.
【００１７】次に，上記熱処理後の成形前においては，
セラミック原料粉末を微粉砕する。その理由は，例えば
セラミック原料中の鉄は熱処理により砕けやすい酸化鉄
になっているので，粉砕によって酸化鉄が焼結後，強度
に影響しない程度に小さく砕かれるからである。上記微
粉砕は，セラミック原料粉末をサブミクロン粒子の大き
さになるように行う。この粉砕は，一般に，エタノー
ル，水等の媒液中で行う。媒液中で粉砕した後，セラミ
ック原料を乾燥する。乾燥は，例えば，セラミック原料
粉末をスプレードライヤー等で噴霧して行う。Next, before the molding after the heat treatment,
Finely pulverize the ceramic raw material powder. The reason is that, for example, the iron in the ceramic raw material becomes iron oxide that is easily broken by heat treatment, and the iron oxide is crushed into small pieces after sintering by crushing to the extent that strength is not affected. The fine pulverization is performed so that the ceramic raw material powder has a submicron particle size. This crushing is generally carried out in a liquid medium such as ethanol or water. After crushing in a liquid medium, the ceramic raw material is dried. The drying is performed, for example, by spraying the ceramic raw material powder with a spray dryer or the like.
【００１８】また，セラミック原料粉末に繊維屑などの
有機系の不純物が混入している場合には，これら，繊維
屑などの有機物系の不純物は，加熱処理により酸化分解
されて，除去される。そのため，セラミック原料の酸化
処理はこれらの有機物系の不純物の除去にも有効であ
る。すなわち，繊維屑等の加熱除去の後に，セラミック
原料に空孔が形成されたとしても，成形時の加圧によっ
て，空孔は消失する。そのため，空孔が無く，強度の高
い焼結体を製造できる。When the ceramic raw material powder contains organic impurities such as fiber dust, these organic impurities such as fiber dust are removed by being oxidized and decomposed by the heat treatment. Therefore, the oxidation treatment of the ceramic raw material is also effective for removing these organic impurities. That is, even if pores are formed in the ceramic raw material after the removal of fiber wastes by heating, the pores disappear due to the pressure applied during the molding. Therefore, it is possible to manufacture a sintered body having no voids and high strength.
【００１９】[0019]
【作用及び効果】本発明の焼結体の製造方法において
は，上記の不純物を含むセラミック原料粉末を，酸化雰
囲気下で熱処理する。これにより，不純物の金属は金属
酸化物となる。例えば，上記不純物の金属が鉄の場合に
は，この熱処理により鉄が酸化鉄となる。この酸化鉄の
ような金属酸化物は，延性がないため，その後の微粉砕
時に容易に粉砕され，細かな粒子となる。従って，焼結
体中で細かな粒子として存在するため，焼結体の強度に
は何ら悪影響を及ぼさない。そのため，本発明では，強
度の高い焼結体が得られる。In the method for producing a sintered body of the present invention, the ceramic raw material powder containing the above impurities is heat-treated in an oxidizing atmosphere. As a result, the metal as an impurity becomes a metal oxide. For example, when the impurity metal is iron, this heat treatment turns iron into iron oxide. Since this metal oxide such as iron oxide has no ductility, it is easily pulverized during subsequent fine pulverization to form fine particles. Therefore, since they exist as fine particles in the sintered body, there is no adverse effect on the strength of the sintered body. Therefore, in the present invention, a high-strength sintered body can be obtained.
【００２０】本発明の製造方法においては，セラミック
原料粉末に，０．０５〜２重量％，特に０．１〜１重量
％の金属粉末が不純物として混入している場合に，上記
のごとき優れた効果を有効に発揮し，特に強度の高い焼
結体が得られる。本発明によれば，上記不純物に基づく
大きな粒子の存在がないため，強度に優れた焼結体の製
造方法を提供することができる。In the production method of the present invention, when the ceramic raw material powder contains 0.05 to 2% by weight, particularly 0.1 to 1% by weight of metal powder as an impurity, the above-mentioned excellent results are obtained. The effect is effectively exhibited, and a sintered body with particularly high strength can be obtained. According to the present invention, since there are no large particles based on the above impurities, it is possible to provide a method for producing a sintered body having excellent strength.
【００２１】[0021]
実施例１ 本発明の実施例にかかる焼結体の製造方法について説明
する。本例の焼結体の製造方法においては，まず，金属
の不純物を含むセラミック原料粉末を酸化雰囲気中で熱
処理を行い，不純物である金属を酸化物に変化させる。
その後，焼結助剤を加え，粉砕，混合し，これを成形し
て，上記セラミック原料粉末を加熱，焼結する。以下，
これを詳説する。Example 1 A method for manufacturing a sintered body according to an example of the present invention will be described. In the method for manufacturing a sintered body of this example, first, a ceramic raw material powder containing a metal impurity is heat-treated in an oxidizing atmosphere to change the metal as an impurity into an oxide.
Then, a sintering aid is added, crushed and mixed, and this is molded, and the ceramic raw material powder is heated and sintered. Less than,
This will be explained in detail.
【００２２】まず，セラミック原料粉末として，０．２
重量％の鉄系金属粉末が不純物として混入している窒化
珪素粉末５００ｇを準備する。この窒化珪素粉末は，粒
径１．５μｍで，α型７０％のシリコン窒化法により製
造されたものである。First, as a ceramic raw material powder, 0.2
500 g of silicon nitride powder in which iron-based metal powder of weight% is mixed as an impurity is prepared. This silicon nitride powder has a grain size of 1.5 μm and is manufactured by an α-type 70% silicon nitriding method.
【００２３】この窒化珪素粉末５００ｇを，径１５０ｍ
ｍ，高さ７０ｍｍの蓋付きアルミナ質容器に充填し，大
気炉で，温度と時間とを変えて，熱処理した。この熱処
理の条件は，表１に示した。次に，熱処理を施した窒化
珪素粉末９２重量％に，焼結助剤としてのイットリア５
重量％とアルミナ３重量％とを加え，更にエタノールを
加えた。次に，これらをボールミルで７２時間粉砕混合
後，スプレードライヤーで噴霧造粒した。造粒粉末を６
×５０×５５ｍｍの板状試料に２００ＭＰａで成形し
た。この成形体を，１８００℃，０．９ＰＭａの窒素中
で４時間加熱し，焼結した。500 g of this silicon nitride powder is
It was filled in an alumina container with a m and a height of 70 mm and having a lid, and heat-treated in an atmospheric furnace at different temperatures and times. The conditions of this heat treatment are shown in Table 1. Next, 92 wt% of the heat-treated silicon nitride powder was added to yttria 5 as a sintering aid.
Wt% and 3 wt% alumina were added, and then ethanol was added. Next, these were pulverized and mixed in a ball mill for 72 hours, and then spray granulated with a spray dryer. 6 granulated powder
It was molded at 200 MPa into a plate-like sample of × 50 × 55 mm. The compact was heated and sintered in nitrogen at 1800 ° C. and 0.9 PMa for 4 hours.
【００２４】次に，この焼結体を，ＪＩＳＲ１６０１に
準拠して，試験片に加工した後，１０本の焼結体につい
て４点法で曲げ強度を測定した。また，同試験片の強度
のワイブル係数を調べた。これらの強度の平均値とワイ
ブル係数とを表１に示した。同表において，試料６〜１
４は，本発明にかかる焼結体である。上記ワイブル係数
とは，１０本の試験片の強度のバラツキを示すものであ
る。Next, this sintered body was processed into a test piece in accordance with JISR1601, and the bending strength of 10 sintered bodies was measured by the 4-point method. The Weibull coefficient of strength of the test piece was also examined. The average value of these intensities and the Weibull coefficient are shown in Table 1. In the table, samples 6 to 1
4 is a sintered body according to the present invention. The above-mentioned Weibull coefficient indicates variations in strength of 10 test pieces.
【００２５】また，比較のために，熱処理無し（試料Ｃ
１），磁石による処理のみ（試料Ｃ２），真空中での熱
処理（試料Ｃ３），０．１ＭＰａのアルゴン中での熱処
理（試料Ｃ４），０．１ＭＰａの窒素中での熱処理（試
料Ｃ５）を行った。その後，上記と同様の条件で焼結助
剤を添加し，成形し，加熱，焼結して，試験片を作製し
た。試料Ｃ３，Ｃ４，Ｃ５の熱処理は，カーボンヒータ
を用いて７００℃で行った。これら比較例としての試料
Ｃ１〜Ｃ５についても，上記と同様の測定を行ない，そ
の強度の平均値とワイブル係数とを表１に示した。For comparison, no heat treatment (Sample C
1), only magnet treatment (sample C2), heat treatment in vacuum (sample C3), heat treatment in argon of 0.1 MPa (sample C4), heat treatment in nitrogen of 0.1 MPa (sample C5). went. Then, a sintering aid was added under the same conditions as above, molded, heated and sintered to prepare a test piece. The heat treatment of Samples C3, C4 and C5 was performed at 700 ° C. using a carbon heater. The samples C1 to C5 as comparative examples were also measured in the same manner as above, and the average value of the strength and the Weibull coefficient are shown in Table 1.
【００２６】同表より知られるように，大気中で熱処理
をした焼結体は，熱処理なし，真空，アルゴン，窒素雰
囲気中で処理したセラミック原料粉末よりも，強度及び
ワイブル係数が高かった。特に，大気中，７００℃で１
０時間の熱処理を行った焼結体（試料１１）は，優れた
強度を発揮した。As is known from the table, the sintered body heat-treated in the atmosphere had higher strength and Weibull coefficient than those of the ceramic raw material powder which was not heat-treated and treated in a vacuum, argon or nitrogen atmosphere. Especially in the atmosphere at 700 ℃
The sintered body (Sample 11) subjected to the heat treatment for 0 hours exhibited excellent strength.
【００２７】[0027]
【表１】 [Table 1]
【００２８】実施例２ 本例においては，金属粉末の混入量と焼結体の強度との
関係を測定した。測定に際し，実施例１と同様の容器
に，不純物としての金属粉末の混入量が異なる窒化珪素
粉末を入れて，大気炉の酸化雰囲気中で，７００℃で，
１０時間の熱処理を行った。その後，この窒化珪素粉末
を，実施例１と同様に焼結助剤を添加し，成形し，加熱
し，焼結して，焼結体を得た。Example 2 In this example, the relationship between the amount of metal powder mixed and the strength of the sintered body was measured. At the time of measurement, silicon nitride powder having a different mixing amount of metal powder as an impurity was put in the same container as in Example 1, and was placed in an oxidizing atmosphere of an atmospheric furnace at 700 ° C.
Heat treatment was performed for 10 hours. Then, this silicon nitride powder was added with a sintering aid, shaped, heated and sintered in the same manner as in Example 1 to obtain a sintered body.
【００２９】次に，上記焼結体の強度及びワイブル係数
を，実施例１と同様にして求め，表２に示した。また，
比較のために，酸化処理を行うことなく上記と同様にし
て作製した焼結体についても，同様の測定を行い，同表
に示した。Next, the strength and Weibull coefficient of the above-mentioned sintered body were determined in the same manner as in Example 1 and are shown in Table 2. Also,
For comparison, the same measurement was performed on the sintered body produced in the same manner as above without the oxidation treatment, and the results are shown in the same table.
【００３０】同表中，試料１６，１８，１１，２０，２
１，２３，２４，２６，２７，２９，３０は，本発明に
かかる焼結体である。一方，試料Ｃ１５，Ｃ１７，Ｃ
１，Ｃ１９，Ｃ２２，Ｃ２５，Ｃ２８は，比較例にかか
る焼結体である。同表より知られるように，同量の金属
粉末が混入している窒化珪素粉末において，酸化雰囲気
中で熱処理を行った場合には，未処理の場合よりも，強
度及びワイブル係数の高い焼結体が得られた。In the table, Samples 16, 18, 11, 20, 2
1, 23, 24, 26, 27, 29 and 30 are sintered bodies according to the present invention. On the other hand, samples C15, C17, C
1, C19, C22, C25 and C28 are sintered bodies according to comparative examples. As can be seen from the table, when the silicon nitride powder containing the same amount of metal powder is heat-treated in an oxidizing atmosphere, it has a higher strength and a higher Weibull coefficient than the untreated one. I got a body.
【００３１】このことから，大気による酸化雰囲気中で
の熱処理を行うことによっても，高い強度の焼結体が得
られることがわかる。特に，金属粉末量が０．０５重量
％以上の場合には，その効果が顕著であった。From this, it is understood that a high-strength sintered body can also be obtained by performing heat treatment in an oxidizing atmosphere in the air. In particular, the effect was remarkable when the amount of metal powder was 0.05% by weight or more.
【００３２】[0032]
【表２】 [Table 2]
【００３３】実施例３ 本例においては，セラミック原料粉末の種類を種々に変
えて，焼結体を作製し，実施例１と同様の測定を行っ
た。セラミック原料粉末として用いた材料は，炭化珪
素，窒化アルミニウム，アルミナ，ジルコニアである。
各セラミック原料粉末を，７００℃，で１０時間の熱処
理を行った。Example 3 In this example, various kinds of ceramic raw material powders were changed to prepare sintered bodies, and the same measurements as in Example 1 were performed. The materials used as the ceramic raw material powder are silicon carbide, aluminum nitride, alumina, and zirconia.
Each ceramic raw material powder was heat-treated at 700 ° C. for 10 hours.
【００３４】炭化珪素には，炭化ホウ素０．５重量％，
カーボン２重量％，及び水を添加した。窒化アルミニウ
ムには，イットリア５重量％，及びエタノールを添加し
た。アルミナには，酸化マグネシウム０．０５重量％と
酸化珪素２重量％と水とを添加した。ジルコニアには，
イットリア４重量％と水とを添加した。上記炭化ホウ
素，カーボン，イットリアなどは，焼結助剤である。Silicon carbide contains 0.5% by weight of boron carbide,
2% by weight of carbon and water were added. To aluminum nitride, 5% by weight of yttria and ethanol were added. 0.05% by weight of magnesium oxide, 2% by weight of silicon oxide and water were added to the alumina. For zirconia,
Yttria 4% by weight and water were added. The above-mentioned boron carbide, carbon, yttria, etc. are sintering aids.
【００３５】その後，上記各セラミック原料粉末を，実
施例１と同様の方法で成形体を作製し，それぞれの材料
の最適な焼結条件で焼結して，それぞれ本発明に係る焼
結体を得た。そして，上記各焼結体について，強度及び
ワイブル係数を実施例１と同様にして求め表３に示し
た。また，比較のために，各セラミック原料粉末につい
て，酸化雰囲気での熱処理をしないで，焼結体を作製し
た。これらの焼結体についても，同様の測定を行い，そ
の結果を表３に示した。Thereafter, each of the above ceramic raw material powders is formed into a compact by the same method as in Example 1, and is sintered under the optimum sintering conditions of the respective materials to obtain the sintered compacts according to the present invention. Obtained. The strength and Weibull coefficient of each of the above-mentioned sintered bodies were determined in the same manner as in Example 1 and shown in Table 3. For comparison, a sintered body was prepared for each ceramic raw material powder without heat treatment in an oxidizing atmosphere. The same measurement was performed on these sintered bodies, and the results are shown in Table 3.
【００３６】同表において，試料３２，３４，３６，３
８は，本発明にかかる焼結体である。試料Ｃ３１，Ｃ３
３，Ｃ３５，Ｃ３７は，比較例にかかる焼結体である。In the table, samples 32, 34, 36 and 3
8 is a sintered body according to the present invention. Samples C31, C3
3, C35 and C37 are sintered bodies according to comparative examples.
【００３７】同表より知られるように，いずれのセラミ
ック原料粉末についても，酸化処理を行った場合には，
高い強度及びワイブル係数を示した。このことから，上
記種々のセラミック原料粉末は，酸化雰囲気中で熱処理
を行うことによって，高い強度の焼結体となることがわ
かる。As is known from the table, when any of the ceramic raw material powders is oxidized,
It showed high strength and Weibull coefficient. From this, it is understood that the various ceramic raw material powders become a high-strength sintered body by heat treatment in an oxidizing atmosphere.
【００３８】[0038]
【表３】 [Table 3]
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.6 識別記号 庁内整理番号 ＦＩ 技術表示箇所 Ｃ０４Ｂ 35/64 Ｌ ─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. 6 Identification code Internal reference number FI technical display location C04B 35/64 L
Claims (4)
ク原料粉末を酸化雰囲気中で熱処理を行い，不純物であ
る金属を酸化物に変化させ，更に該セラミック原料粉末
を微粉砕し，次いで成形し，その後該成形体を加熱，焼
結することを特徴とする焼結体の製造方法。1. A ceramic raw material powder mixed with impurities made of a metal is heat-treated in an oxidizing atmosphere to convert the metal as an impurity into an oxide, and the ceramic raw material powder is further finely pulverized and then molded. A method for producing a sintered body, which comprises heating and sintering the formed body.
０〜１０００℃で行うことを特徴とする焼結体の製造方
法。2. The heat treatment according to claim 1, wherein the heat treatment is 50
A method for producing a sintered body, which is performed at 0 to 1000 ° C.
は，０．５〜２０時間行うことを特徴とする焼結体の製
造方法。3. The method for manufacturing a sintered body according to claim 1, wherein the heat treatment is performed for 0.5 to 20 hours.
ラミック原料粉末には，焼結助剤を添加混合することを
特徴とする焼結体の製造方法。4. The method for producing a sintered body according to claim 1, 2, or 3, wherein a sintering aid is added to and mixed with the ceramic raw material powder.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6148666A JPH07330440A (en) | 1994-06-06 | 1994-06-06 | Production of sintered compact |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6148666A JPH07330440A (en) | 1994-06-06 | 1994-06-06 | Production of sintered compact |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH07330440A true JPH07330440A (en) | 1995-12-19 |
Family
ID=15457909
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6148666A Pending JPH07330440A (en) | 1994-06-06 | 1994-06-06 | Production of sintered compact |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH07330440A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003095736A (en) * | 2001-09-19 | 2003-04-03 | Kyocera Corp | Dielectric ceramic, production method therefor, and dielectric resonator obtained by using the same |
| JP2013159514A (en) * | 2012-02-03 | 2013-08-19 | Shinagawa Refractories Co Ltd | Method for manufacturing alumina-zirconia refractory raw material, alumina-zirconia refractory raw material, and plate refractory |
-
1994
- 1994-06-06 JP JP6148666A patent/JPH07330440A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003095736A (en) * | 2001-09-19 | 2003-04-03 | Kyocera Corp | Dielectric ceramic, production method therefor, and dielectric resonator obtained by using the same |
| JP2013159514A (en) * | 2012-02-03 | 2013-08-19 | Shinagawa Refractories Co Ltd | Method for manufacturing alumina-zirconia refractory raw material, alumina-zirconia refractory raw material, and plate refractory |
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