JPH06144918A - Production of ceramic granulated powder and production of ceramic sintered body - Google Patents
Production of ceramic granulated powder and production of ceramic sintered bodyInfo
- Publication number
- JPH06144918A JPH06144918A JP4301231A JP30123192A JPH06144918A JP H06144918 A JPH06144918 A JP H06144918A JP 4301231 A JP4301231 A JP 4301231A JP 30123192 A JP30123192 A JP 30123192A JP H06144918 A JPH06144918 A JP H06144918A
- Authority
- JP
- Japan
- Prior art keywords
- ceramic
- granulated powder
- powder
- slurry
- sintered body
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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- Glanulating (AREA)
- 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ス造粒粉の製
造方法およびその造粒粉を用いたセラミックス焼結体の
製造方法に係り、特に原料粉中に添加するバインダの変
質や硬化が起らず、欠陥の発生が少ない焼結体を得るこ
とが可能なセラミックス造粒粉およびその造粒粉を使用
したセラミックス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 ceramic granulated powder and a method for producing a ceramic sintered body using the granulated powder, and in particular, deterioration or hardening of a binder added to raw material powder occurs. The present invention relates to a ceramic granulated powder capable of obtaining a sintered body having few defects and a method for manufacturing a ceramic sintered body using the granulated powder.
【０００２】[0002]
【従来の技術】従来の金属原料と比較して耐熱性および
耐摩耗特性等に優れたセラミックス製品が広い分野で普
及している。これらのセラミックス製品は、セラミック
ス原料粉末にバインダーおよび焼結助剤を添加した混合
体を所定形状に成形し、得られた成形体を脱脂焼結して
製造される。2. Description of the Related Art Ceramic products, which are superior in heat resistance and wear resistance to conventional metal raw materials, are widely used in a wide range of fields. These ceramic products are manufactured by molding a mixture obtained by adding a binder and a sintering aid to a ceramic raw material powder into a predetermined shape and degreasing and sintering the obtained molded body.
【０００３】特に冷間静水圧法（ＣＩＰ：Cold Isostat
ic Pressing ）や金型プレス法にて成形操作を行う場合
には、微細なセラミックス原料粉末の飛散を防止し、そ
の取扱性を改善したり、さらに原料の流動性を改善し、
成形用金型内への均一な充填を可能とするため、上記粉
末混合体をある程度の粒径を持つセラミックス造粒粉に
して使用することが有効である。In particular, the cold isostatic method (CIP: Cold Isostat)
ic Pressing) or a die pressing method, it is possible to prevent the scattering of fine ceramic raw material powder, improve its handling, and improve the fluidity of the raw material.
In order to enable uniform filling in the molding die, it is effective to use the above powder mixture as a granulated ceramic powder having a certain particle size.
【０００４】そして従来上記セラミックス造粒粉は、微
細なセラミックス原料粉末に焼結助剤と樹脂等のバイン
ダとを添加混合し、さらに水や溶剤などの分散媒を添加
してスラリー（泥漿）状に調製し、得られたスラリーを
熱風型のスプレー乾燥装置において噴霧乾燥して製造し
ていた。Conventionally, the above-mentioned ceramic granulated powder has a slurry (slurry) state in which a sintering aid and a binder such as a resin are added to and mixed with a fine ceramic raw material powder, and a dispersion medium such as water or a solvent is further added. Was prepared, and the resulting slurry was spray-dried in a hot-air type spray dryer to manufacture.
【０００５】上記スプレー乾燥装置は、例えば図２に示
すように、セラミックス原料のスラリーを高圧流体によ
って分散微細化するアトマイザー１と、分散微細化され
たスラリー粒子２を乾燥して所定粒径のセラミックス造
粒粉３を形成するスプレー乾燥塔４と、スプレー乾燥塔
４に乾燥用熱源としての熱風を供給する熱風発生用ヒー
タ５と、スプレー乾燥塔４から排出される排気中に含ま
れる粗大粒子を分離するサイクロン６と、このサイクロ
ン６からの排気中に含まれる微細粒子を分離するバグフ
ィルタ７と、バグフィルタ７からの排気を系外に排出す
る排風機８とから構成される。The above spray dryer, for example, as shown in FIG. 2, atomizes a ceramic raw material slurry by a high-pressure fluid for atomization, and an atomizer 1 for dispersing and atomizing the slurry to dry ceramics of a predetermined particle size. The spray drying tower 4 for forming the granulated powder 3, the hot air generating heater 5 for supplying hot air as a heat source for drying to the spray drying tower 4, and the coarse particles contained in the exhaust gas discharged from the spray drying tower 4 It is composed of a cyclone 6 to be separated, a bag filter 7 for separating fine particles contained in the exhaust gas from the cyclone 6, and an exhaust fan 8 for discharging the exhaust gas from the bag filter 7 to the outside of the system.
【０００６】セラミックス粉末、焼結助剤および有機バ
インダ等を分散媒中に均一に分散した原料スラリーは、
アトマイザ１のノズルにおいてアトマイズ用高圧流体に
よって噴霧化され、スプレー乾燥塔４内に噴出される。
噴出されたスラリー粒子２は、熱風発生用ヒータ５から
供給された熱風によって乾燥され、所定の粒径を有する
セラミックス造粒粉３となる。生成したセラミックス造
粒粉３は、取出口９から排出され、次の成形工程に搬送
される。一方スプレー乾燥塔４から排出された排気中に
含有される粗大粒子および微細粒子はそれぞれサイクロ
ン６およびバグフィルタ７にて分離される。A raw material slurry in which ceramic powder, a sintering aid, an organic binder and the like are uniformly dispersed in a dispersion medium is
It is atomized by the atomizing high-pressure fluid in the nozzle of the atomizer 1 and is ejected into the spray drying tower 4.
The ejected slurry particles 2 are dried by the hot air supplied from the hot air generating heater 5 and become the ceramic granulated powder 3 having a predetermined particle size. The produced ceramic granulated powder 3 is discharged from the outlet 9 and conveyed to the next molding step. On the other hand, coarse particles and fine particles contained in the exhaust gas discharged from the spray drying tower 4 are separated by the cyclone 6 and the bag filter 7, respectively.
【０００７】[0007]
【発明が解決しようとする課題】しかしながら上記従来
のセラミックス造粒粉の製造方法によると、乾燥効率を
高めるため熱風発生用ヒータから送給される熱風の温度
を１２０〜２００℃と高温に設定する必要があった。そ
のため、原料スラリー中に含有される有機バインダーが
熱風によって変質したり硬化し、セラミックス造粒粉自
体が硬化してしまう欠点があった。そしてそのセラミッ
クス造粒粉を使用して、成形体を形成すると、各セラミ
ックス造粒粉が硬くつぶれにくいために成形体内に残粒
界が残ってしまう。そして残粒界を有する成形体を焼成
すると、残粒界はそのままポアとして焼結体内部に残留
し、欠陥が多いセラミックス焼結体しか得られないとい
う問題点があった。However, according to the above-described conventional method for producing ceramic granulated powder, the temperature of the hot air sent from the hot air generating heater is set to a high temperature of 120 to 200 ° C. in order to improve the drying efficiency. There was a need. Therefore, there is a drawback that the organic binder contained in the raw material slurry is altered or hardened by the hot air, and the ceramic granulated powder itself is hardened. When a molded body is formed using the ceramic granulated powder, each ceramic granulated powder is hard and difficult to be crushed, so that residual grain boundaries remain in the molded body. When the compact having the residual grain boundaries is fired, the residual grain boundaries remain as pores inside the sintered body, and only a ceramic sintered body having many defects is obtained.
【０００８】例えばＳｉＣ（炭化けい素）粉末を混合造
粒する場合で、炭素源となる助剤およびバインダを兼ね
たフェノールレジン系樹脂を原料粉末に添加混合してス
ラリーを調製し、得られたスラリーを熱風による噴霧乾
燥に供して造粒粉を調製していた。しかしフェノールレ
ジン系樹脂は、熱硬化性を有するため１２０〜２００℃
の熱風によって容易に変質硬化し、成形時に高圧力で加
圧しても圧密化が進まないような成形性が悪化したセラ
ミックス造粒粉になってしまい、必然的に得られるセラ
ミックス焼結体の欠陥も増加し、製品歩留りが大幅に低
下してしまう問題点があった。For example, in the case of mixing and granulating SiC (silicon carbide) powder, a slurry was prepared by adding and mixing a phenol resin resin, which also serves as a carbon source auxiliary agent and a binder, to the raw material powder. The slurry was subjected to spray drying with hot air to prepare granulated powder. However, since the phenolic resin is thermosetting, it is 120 to 200 ° C.
Defects of the ceramic sintered body inevitably obtained due to the ceramic granulated powder which is easily deteriorated and hardened by the hot air and does not proceed to compaction even at high pressure during molding, resulting in poor moldability. However, there is a problem that the product yield is significantly reduced.
【０００９】本発明は上記の問題点を解決するためにな
されたものであり、セラミックス原料スラリー中に含有
するバインダの変質硬化を防止し、成形性が優れたセラ
ミックス造粒粉を得ることが可能なセラミックス造粒粉
の製造方法およびその造粒粉を用いて、欠陥が少ない焼
結体を得ることができるセラミックス焼結体の製造方法
を提供することにある。The present invention has been made to solve the above problems, and it is possible to prevent alteration hardening of a binder contained in a ceramic raw material slurry and obtain a ceramic granulated powder having excellent formability. Another object of the present invention is to provide a method for producing a ceramics granulated powder, and a method for producing a ceramics sintered body which can obtain a sintered body with few defects by using the granulated powder.
【００１０】[0010]
【課題を解決するための手段】本願発明者は原料スラリ
ー中に含有される有機バインダの変質硬化を防止できる
処理方法を種々検討した結果、スラリーを加熱せずに減
圧雰囲気ないし真空雰囲気においてもスラリーを充分に
乾燥でき、特にバインダの変質硬化を招くことなく所定
粒径のセラミックス造粒粉を効率的に製造できるという
知見を得た。本発明は上記知見に基づいて完成したもの
である。As a result of various studies on a treatment method capable of preventing alteration hardening of an organic binder contained in a raw material slurry, the present inventor has found that the slurry can be used even in a reduced pressure atmosphere or a vacuum atmosphere without heating the slurry. It was found that the powder can be sufficiently dried and that the ceramic granulated powder having a predetermined particle diameter can be efficiently produced without causing deterioration and hardening of the binder. The present invention has been completed based on the above findings.
【００１１】すなわち本発明に係るセラミックス造粒粉
の製造方法は、セラミックス原料粉末に焼結助剤、バイ
ンダおよび分散剤を添加混合して均一なスラリーを調製
し、得られたスラリーを所定真空度の減圧容器内で噴霧
乾燥することにより、所定の平均粒径を有するセラミッ
クス造粒粉を形成することを特徴とする。That is, in the method for producing a ceramic granulated powder according to the present invention, a sintering aid, a binder and a dispersant are added to and mixed with a ceramic raw material powder to prepare a uniform slurry, and the obtained slurry is subjected to a predetermined vacuum degree. The method is characterized in that a ceramic granulated powder having a predetermined average particle diameter is formed by spray drying in the reduced pressure container.
【００１２】また本発明に係るセラミックス焼結体の製
造方法は、上記製造方法によってセラミックス造粒粉を
製造し、このセラミックス造粒粉を所定形状に成形した
後、不活性ガス雰囲気中で焼結することを特徴とする。In the method for producing a ceramics sintered body according to the present invention, the ceramics granulated powder is produced by the above-described manufacturing method, the ceramics granulated powder is molded into a predetermined shape, and then sintered in an inert gas atmosphere. It is characterized by doing.
【００１３】ここで、前記セラミックス原料粉末として
は、各種無機質の化合物を主体とする粉末であって、そ
のうちでも特に代表的なものを例示すれば、アルミナ、
ジルコニア、チタニア、ムライト、ベリリア、ジルコニ
ア、サイアロン、窒化珪素、炭化珪素、窒化アルミニウ
ム、窒化硼素もしくはフェライトなどの酸化物系ならび
に非酸化物系の汎用セラミックス原料の一種あるいはこ
れらの混合物を主体とする。Here, the ceramic raw material powder is a powder mainly composed of various inorganic compounds, of which a typical one is alumina,
It is mainly composed of one or a mixture of oxide-based and non-oxide-based general-purpose ceramic raw materials such as zirconia, titania, mullite, beryllia, zirconia, sialon, silicon nitride, silicon carbide, aluminum nitride, boron nitride or ferrite.
【００１４】さらに炭酸マグネシウム、炭酸カルシウ
ム、酸化イットリウム、酸化セリウムもしくは珪酸など
のような公知慣用の焼結助剤や、Ｌｉ2 Ｏ、ＢａＯ、Ｔ
ａ2 Ｏ3 、ＰｔもしくはＰｄなどの電気的性質を変化さ
せるような各種の添加剤を加えてもよい。Further, known conventional sintering aids such as magnesium carbonate, calcium carbonate, yttrium oxide, cerium oxide or silicic acid, Li 2 O, BaO, T and the like.
Various additives such as a 2 O 3 , Pt, or Pd that change the electrical properties may be added.
【００１５】他方、前記したバインダーとしては不飽和
ポリエステル樹脂、フェノール樹脂、アミノ系樹脂、エ
ポキシ樹脂、ジアリルフタレート樹脂、熱硬化型ウレタ
ン樹脂または熱硬化型アクリル樹脂などの熱硬化性樹脂
が代表的なものであるが、特に、不飽和ポリエステル樹
脂が好ましい。On the other hand, as the binder, a thermosetting resin such as unsaturated polyester resin, phenol resin, amino resin, epoxy resin, diallyl phthalate resin, thermosetting urethane resin or thermosetting acrylic resin is typical. However, an unsaturated polyester resin is particularly preferable.
【００１６】また分散剤としては純水、またはエタノー
ルなどの有機溶媒が一般的に使用される。上記スラリー
を調製するに際しての混合比は、前記セラミックス原料
粉末１００重量部に対して、焼結助剤１〜７重量部、バ
インダを５〜６０重量部、好ましくは１０〜４０重量
部、配合する。また分散剤は上記セラミックス原料粉末
と焼結助剤と、バインダとの混合物に対して３０〜６０
vol%添加する。As the dispersant, pure water or an organic solvent such as ethanol is generally used. The mixing ratio for preparing the slurry is 1 to 7 parts by weight of a sintering aid and 5 to 60 parts by weight, preferably 10 to 40 parts by weight, based on 100 parts by weight of the ceramic raw material powder. . The dispersant is 30 to 60 with respect to the mixture of the ceramic raw material powder, the sintering aid, and the binder.
Add vol%.
【００１７】上記スラリーを微細に噴霧するアトマイザ
としては、金属焼結体の原料となる金属アトマイズ粉を
溶湯金属法によって製造する際に使用する汎用のアトマ
イザがそのまま使用できる。セラミックス造粒粉の平均
粒径は成形性に大きく影響し、本発明では５０μｍ以下
に設定される。平均粒径が５０μｍを越えると、成形時
の圧密性が低下し、高い成形圧力を加えても、成形体内
部に微小な空隙が残留し易いからである。この造粒粉の
平均粒径は、アトマイザのスラリ噴出口の口径およびア
トマイズ用高圧流体の圧力を変えることによって任意に
設定することができる。As the atomizer for finely spraying the above-mentioned slurry, a general-purpose atomizer used when producing a metal atomized powder as a raw material of a metal sintered body by a molten metal method can be used as it is. The average particle size of the ceramic granulated powder greatly affects the formability, and is set to 50 μm or less in the present invention. When the average particle size exceeds 50 μm, the compaction property at the time of molding is deteriorated, and even if a high molding pressure is applied, minute voids are likely to remain inside the molded body. The average particle size of the granulated powder can be arbitrarily set by changing the diameter of the slurry ejection port of the atomizer and the pressure of the high-pressure atomizing fluid.
【００１８】また減圧容器内の真空度はスラリの乾燥効
率に大きく影響し、本発明では５０Torr以下に設定され
る。真空度が５０Torrを越えるとスラリの乾燥効率が急
激に低下し、造粒粉の生産効率が低下するからである。The degree of vacuum in the decompression container has a great influence on the drying efficiency of the slurry, and is set to 50 Torr or less in the present invention. This is because when the degree of vacuum exceeds 50 Torr, the slurry drying efficiency sharply decreases and the granulated powder production efficiency decreases.
【００１９】こうして調製されたセラミックス造粒粉
は、汎用の金型成形法、冷間静水圧法によって所定形状
に加圧成形され、得られた成形体は、Ｈｅ，Ａｒなどの
不活性ガス雰囲気中で、各セラミックス原料の特性に適
した温度（１２００〜１９００℃）で１〜１０時間焼結
され、セラミックス焼結体とされる。The thus-prepared ceramic granulated powder is pressure-molded into a predetermined shape by a general-purpose die molding method or cold isostatic pressing method, and the obtained molded body is in an inert gas atmosphere such as He or Ar. Inside, a ceramic sintered body is obtained by sintering at a temperature (1200 to 1900 ° C.) suitable for the characteristics of each ceramic raw material for 1 to 10 hours.
【００２０】[0020]
【作用】上記セラミックス造粒粉の製造方法およびセラ
ミックス焼結体の製造方法によれば、セラミックス造粒
粉の製造工程において、バインダーを含有するスラリー
を、熱風を使用せずに常温の減圧雰囲気で噴霧乾燥して
いるため、バインダや焼結助剤の熱による変性硬化が少
ない。従って、得られたセラミックス造粒粉は成形時の
加圧操作によって容易に圧潰され、空隙のない緻密な成
形体が得られる。そのため、この造粒粉を使用して形成
された成形体を焼成することにより、ポアやふくれ等の
欠陥が少ない高品質のセラミックス焼結体を得ることが
できる。According to the above-mentioned ceramic granulated powder manufacturing method and ceramic sintered body manufacturing method, in the ceramic granulated powder manufacturing process, the slurry containing the binder is treated in a reduced pressure atmosphere at room temperature without using hot air. Since it is spray-dried, there is little denaturation and hardening of the binder and sintering aid due to heat. Therefore, the obtained ceramic granulated powder is easily crushed by the pressing operation at the time of molding, and a dense compact without voids can be obtained. Therefore, by firing a molded body formed using this granulated powder, it is possible to obtain a high quality ceramics sintered body with few defects such as pores and blisters.
【００２１】[0021]
【実施例】次に本発明を下記に示す実施例に基づいて、
より具体的に説明する。図１は本発明方法を実施するた
めに用意したスプレー乾燥装置の構成例を示す系統図で
ある。EXAMPLES Next, the present invention will be described based on the following examples.
This will be described more specifically. FIG. 1 is a system diagram showing a configuration example of a spray drying apparatus prepared for carrying out the method of the present invention.
【００２２】この図１に示すスプレー乾燥装置は、図２
に示すスプレー乾燥装置に示す熱風発生用ヒータ５を省
略し、新たにスプレー乾燥塔４内を減圧する真空ポンプ
１０と、真空ポンプ１０からの排気中に含有される油ミ
ストを除去するオイルセパレータ１１とを付設した点を
除き、図２に示す従来のスプレー乾燥装置とほぼ同一の
構成を有する。The spray drying apparatus shown in FIG.
The heater 5 for generating hot air shown in the spray drying apparatus shown in FIG. 2 is omitted, and a vacuum pump 10 for newly depressurizing the inside of the spray drying tower 4 and an oil separator 11 for removing oil mist contained in exhaust gas from the vacuum pump 10 are omitted. It has almost the same configuration as the conventional spray drying apparatus shown in FIG.
【００２３】実施例１ 実施例１のセラミックス原料粉末として平均粒径０．５
μｍのＳｉＣ粉末に対して焼結助剤としてのＢ4 Ｃを１
重量％およびバインダーとしての熱硬化性フェノール樹
脂を６重量％添加した混合体に対して６０vol%の純水を
分散剤として添加し混合粉砕した後に、混合体を６０メ
ッシュの標準篩で通篩し、セラミックス原料粉末等を均
一に分散したスラリーを得た。The average particle size of 0.5 as the ceramic raw material powder of Example 1 Example 1
1 μm of B 4 C as a sintering aid for μm SiC powder
Wt% and 6 wt% of thermosetting phenolic resin as a binder were added to the mixture, 60 vol% of pure water was added as a dispersant, and the mixture was pulverized, and then the mixture was passed through a 60 mesh standard sieve. A slurry in which the ceramic raw material powder and the like were uniformly dispersed was obtained.
【００２４】次に得られたスラリーを図１に示すスプレ
ー乾燥装置のディスク式アトマイザ１に高圧空気ととも
に供給して、噴霧乾燥を実施した。乾燥時におけるスプ
レー乾燥塔４内の真空度は３０Torrであり、温度は３５
℃であった。Next, the obtained slurry was supplied to the disk atomizer 1 of the spray dryer shown in FIG. 1 together with high pressure air to carry out spray drying. The degree of vacuum in the spray drying tower 4 during drying was 30 Torr, and the temperature was 35.
It was ℃.
【００２５】そして得られたＳｉＣ造粒粉を取出口９よ
り排出して、６０メッシュの標準篩で通篩して、平均粒
径が２５０μｍのＳｉＣセラミックス造粒粉３ａを得
た。得られたセラミックス造粒粉３ａの残留水分は０．
６重量％である一方、安息角は２８度であり、ほぼ従来
の熱風乾燥によって製造した後述の比較例１の造粒粉と
ほぼ同一値であった。The obtained SiC granulated powder was discharged from the outlet 9 and passed through a 60 mesh standard sieve to obtain SiC ceramic granulated powder 3a having an average particle size of 250 μm. The residual water content of the obtained ceramic granulated powder 3a was 0.
While it was 6% by weight, the angle of repose was 28 degrees, which was almost the same value as the granulated powder of Comparative Example 1 described later produced by conventional hot air drying.
【００２６】次に上記造粒粉を縦５０mm、横５０mmの金
型に充填して加圧力１ton ／cm2 でプレス成形して５０
個の成形体を調製した。各成形体表面を倍率４００の顕
微鏡で観察した結果、いずれの成形体においても造粒粉
は完全に押し潰されており、隣接する造粒粉間に隙間が
存在するものは観察されなかった。Next, the above-mentioned granulated powder is filled in a mold having a length of 50 mm and a width of 50 mm and press-molded with a pressing force of 1 ton / cm 2 to obtain 50.
Individual molded bodies were prepared. As a result of observing the surface of each compact with a microscope at a magnification of 400, the granulated powder was completely crushed in any of the compacts, and no gap was present between adjacent granulated powders.
【００２７】さらに各成形体をＮ2 ガス雰囲気中で温度
８００℃で２時間脱脂し、各脱脂体表面を同様に顕微鏡
観察した結果、隙間は観察されなかった。Further, as a result of degreasing each molded body in an N 2 gas atmosphere at a temperature of 800 ° C. for 2 hours and observing the surface of each degreased body with a microscope in the same manner, no gap was observed.
【００２８】次に各脱脂体をＡｒ雰囲気中で温度２１５
０℃で５時間加圧焼結してＳｉＣ焼結体を製造した。Next, each degreased body is heated to a temperature of 215 in an Ar atmosphere.
A SiC sintered body was manufactured by pressure sintering at 0 ° C. for 5 hours.
【００２９】得られた各ＳｉＣ焼結体の表面を顕微鏡観
察したが、ポア等の欠陥は観察されなかった。また各Ｓ
ｉＣ焼結体をアルキメデス法により密度測定を行うとと
もに、日本工業規格（ＪＩＳ）Ｒ１６０１に規定する３
点曲げ試験を、常温および１３００℃の温度条件下で実
施し、表１に示す結果を得た。また測定値のばらつきを
示すワイブル係数ｍを算出し併せて表１に示す。焼結体
密度および３点曲げ強度はいずれも５０個の試験体の平
均値を示す。The surface of each obtained SiC sintered body was observed under a microscope, but no defects such as pores were observed. Also each S
The density of the iC sintered body is measured by the Archimedes method, and is specified in Japanese Industrial Standard (JIS) R1601. 3
The point bending test was performed at room temperature and a temperature of 1300 ° C., and the results shown in Table 1 were obtained. In addition, Table 1 also shows the Weibull coefficient m indicating the dispersion of the measured values. The sintered body density and the three-point bending strength are average values of 50 test bodies.
【００３０】比較例１ 比較例１として、実施例１で使用したスラリーを、図２
に示す従来のスプレー乾燥装置を使用して温度１５０℃
で熱風噴霧乾燥処理を行い、実施例１で調製したものと
同一粒径（２５０μｍ）で同一含水率（０．６wt% ）の
ＳｉＣ造粒粉を調製し、以下実施例１と同様に成形、脱
脂、焼結して５０個のＳｉＣ焼結体を製造し、実施例１
と同様に各特性を測定し、表１に示す結果を得た。 Comparative Example 1 As Comparative Example 1, the slurry used in Example 1 was prepared as shown in FIG.
Using the conventional spray dryer shown in Fig.
Hot air spray drying treatment was carried out to prepare a SiC granulated powder having the same particle size (250 μm) and the same water content (0.6 wt%) as that prepared in Example 1, followed by molding in the same manner as in Example 1, Example 1 was carried out by degreasing and sintering to produce 50 SiC sintered bodies.
Each property was measured in the same manner as in, and the results shown in Table 1 were obtained.
【００３１】実施例２ セラミックス原料粉末としての平均粒径２０μｍのＳｉ
3 Ｎ4 粉末に、焼結助剤としてのＹ2 Ｏ3 を２重量％、
バインダーとしてのアクリルエマルジョン熱硬化性樹脂
を６wt% を添加した混合体に、分散剤としてのトリクロ
ロエタンを６０vol%添加した他は実施例１と同一条件で
スラリーを噴霧乾燥して造粒粉を形成し、引き続き成
形、脱脂、焼結して、実施例２の造粒粉、成形体、脱脂
体および焼結体を形成し、実施例１と同様に各特性を測
定評価し、表１に示す結果を得た。 Example 2 Si having an average particle size of 20 μm as a ceramic raw material powder
2% by weight of Y 2 O 3 as a sintering aid to 3 N 4 powder,
A slurry was spray-dried under the same conditions as in Example 1 except that 60 vol% of trichloroethane as a dispersant was added to a mixture containing 6 wt% of an acrylic emulsion thermosetting resin as a binder to form granulated powder. Then, the granulated powder, molded body, degreased body and sintered body of Example 2 were formed by subsequent molding, degreasing and sintering, and each characteristic was measured and evaluated in the same manner as in Example 1, and the results shown in Table 1 were obtained. Got
【００３２】比較例２ 実施例２において調製したスラリーを図２に示す従来の
スプレー乾燥装置を使用して温度１２０℃で熱風乾燥し
た以外は実施例２と同一条件で造粒、成形、脱脂、焼結
して比較例２の造粒粉、成形体、脱脂体、焼結体を形成
し、実施例２と同様な特性評価を行い下記表１に示す結
果を得た。 Comparative Example 2 The slurry prepared in Example 2 was granulated, molded, degreased under the same conditions as in Example 2 except that the conventional spray dryer shown in FIG. The granulated powder, the molded body, the degreased body, and the sintered body of Comparative Example 2 were formed by sintering, and the same characteristic evaluation as in Example 2 was performed, and the results shown in Table 1 below were obtained.
【００３３】[0033]
【表１】 [Table 1]
【００３４】表１に示す結果から明らかなように、実施
例１〜２に係るセラミックス造粒粉は、熱硬化性樹脂を
バインダとして含有するスラリーを、熱風を使用せずに
常温の減圧雰囲気で噴霧乾燥して製造しているため、バ
インダや焼結助剤の熱による変性硬化が少ない。各成形
体表面を顕微鏡観察すると、造粒粉がよく潰れており、
隙間は観察されず、成形性が極めて優れている。その結
果、焼結体の３点曲げ強度も高く、またワイブル係数も
高く、強度のばらつきが少ない高品質の焼結体が得られ
ている。As is clear from the results shown in Table 1, the ceramic granulated powders according to Examples 1 and 2 were prepared by using a slurry containing a thermosetting resin as a binder in a reduced pressure atmosphere at room temperature without using hot air. Since it is manufactured by spray drying, there is little denaturation and hardening of the binder and sintering aid due to heat. When observing the surface of each molded body with a microscope, the granulated powder is well crushed,
No gaps were observed and the moldability was extremely excellent. As a result, the three-point bending strength of the sintered body is high, the Weibull coefficient is also high, and a high-quality sintered body with little variation in strength is obtained.
【００３５】特に、熱硬化性樹脂をバインダー兼焼結助
剤として含有するＳｉＣセラミックススラリーは、熱風
を使用せずに容易に噴霧乾燥造粒することが可能であ
る。また、得られた造粒粉は、品質的に安定性が高く、
かつ硬化しないためプレス成形時に潰れ易いという成形
性に優れたものであった。In particular, a SiC ceramics slurry containing a thermosetting resin as a binder and a sintering aid can be easily spray-dried and granulated without using hot air. Further, the obtained granulated powder has high quality stability,
In addition, since it did not harden, it was easy to be crushed during press molding and had excellent moldability.
【００３６】一方、比較例１〜２においては、熱風乾燥
に起因するセラミックス造粒粉の硬化が顕著であるた
め、成形時の加圧操作においても、充分に潰れず、成形
体、樹脂体のいずれの表面にも空隙が観察された上に、
焼結体にもポアが多く、密度および強度が共に低下して
しまう傾向が確認された。On the other hand, in Comparative Examples 1 and 2, since the ceramic granulated powder is significantly hardened due to the hot air drying, the ceramic granulated powder was not crushed sufficiently even in the pressurizing operation at the time of molding, and the molded body and the resin body were In addition to observing voids on both surfaces,
It was confirmed that the sintered body also had many pores, and both the density and strength tended to decrease.
【００３７】[0037]
【発明の効果】以上の通り、本発明に係るセラミックス
造粒粉の製造方法およびセラミックス焼結体の製造方法
によれば、セラミックス造粒粉の製造工程において、バ
インダーを含有するスラリーを、熱風を使用せずに常温
の減圧雰囲気で噴霧乾燥しているため、バインダや焼結
助剤の熱による変性硬化が少ない。従って、得られたセ
ラミックス造粒粉は成形時の加圧操作によって容易に圧
潰され、空隙のない緻密な成形体が得られる。そのた
め、成形体を焼成することにより、ポアやふくれ等の欠
陥が少ない高品質のセラミックス焼結体を得ることがで
きる。As described above, according to the method for producing a ceramic granulated powder and the method for producing a ceramic sintered body according to the present invention, the slurry containing the binder is heated with hot air in the process for producing the ceramic granulated powder. Since it is not used and spray-dried in a vacuum atmosphere at room temperature, there is little denaturation and hardening of the binder and sintering aid due to heat. Therefore, the obtained ceramic granulated powder is easily crushed by the pressing operation at the time of molding, and a dense compact without voids can be obtained. Therefore, by firing the molded body, it is possible to obtain a high-quality ceramics sintered body with few defects such as pores and blisters.
【図１】本発明方法を実施するためのスプレー乾燥装置
の構成例を示す系統図。FIG. 1 is a system diagram showing a configuration example of a spray drying apparatus for carrying out the method of the present invention.
【図２】従来のスプレー乾燥装置の構成例を示す系統
図。FIG. 2 is a system diagram showing a configuration example of a conventional spray drying device.
【符号の説明】 １ アトマイザー ２ スラリー粒子 ３，３ａ セラミックス造粒粉 ４ スプレー乾燥塔 ５ 熱風発生用ヒータ ６ サイクロン ７ バグフィルタ ８ 排風機 ９ 取出口 １０ 真空ポンプ １１ オイルセパレータ[Explanation of symbols] 1 atomizer 2 slurry particles 3, 3a ceramic granulated powder 4 spray drying tower 5 heater for generating hot air 6 cyclone 7 bag filter 8 exhaust fan 9 outlet 10 vacuum pump 11 oil separator
Claims (4)
ンダおよび分散剤を添加混合して均一なスラリーを調製
し、得られたスラリーを所定真空度の減圧容器内で噴霧
乾燥することにより、所定の平均粒径を有するセラミッ
クス造粒粉を形成することを特徴とするセラミックス造
粒粉の製造方法。1. A ceramic raw material powder to which a sintering aid, a binder and a dispersant are added and mixed to prepare a uniform slurry, and the resulting slurry is spray-dried in a depressurized container having a predetermined vacuum degree to obtain a predetermined slurry. A method for producing a ceramic granulated powder, which comprises forming a ceramic granulated powder having an average particle diameter of 1.
定することを特徴とする請求項１記載のセラミックス造
粒粉の製造方法。2. The method for producing a ceramic granulated powder according to claim 1, wherein the degree of vacuum in the decompression container is set to 50 Torr or less.
ｍ以下に設定することを特徴とする請求項１記載のセラ
ミックス造粒粉の製造方法。3. The average particle size of the ceramic granulated powder is 50 μm.
The method for producing a ceramic granulated powder according to claim 1, wherein the method is set to m or less.
ミックス造粒粉を製造し、このセラミックス造粒粉を所
定形状に成形した後、不活性ガス雰囲気中で焼結するこ
とを特徴とするセラミックス焼結体の製造方法。4. A ceramics characterized by producing a ceramics granulated powder by the manufacturing method according to claim 1, shaping the ceramics granulated powder into a predetermined shape, and sintering the powder in an inert gas atmosphere. Manufacturing method of sintered body.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4301231A JPH06144918A (en) | 1992-11-11 | 1992-11-11 | Production of ceramic granulated powder and production of ceramic sintered body |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4301231A JPH06144918A (en) | 1992-11-11 | 1992-11-11 | Production of ceramic granulated powder and production of ceramic sintered body |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH06144918A true JPH06144918A (en) | 1994-05-24 |
Family
ID=17894358
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4301231A Pending JPH06144918A (en) | 1992-11-11 | 1992-11-11 | Production of ceramic granulated powder and production of ceramic sintered body |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH06144918A (en) |
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| GB2384208A (en) * | 2001-11-13 | 2003-07-23 | Pentax Corp | Making a sintered piece in atmosphere of oxygen |
| US7563608B2 (en) | 2002-08-12 | 2009-07-21 | Hoya Corporation | Method for manufacturing a sintered compact for use as a cell culture base |
| JP2012149353A (en) * | 2007-03-09 | 2012-08-09 | Mitsubishi Materials Corp | Method for producing vapor deposition material |
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-
1992
- 1992-11-11 JP JP4301231A patent/JPH06144918A/en active Pending
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|---|---|---|---|---|
| GB2384208A (en) * | 2001-11-13 | 2003-07-23 | Pentax Corp | Making a sintered piece in atmosphere of oxygen |
| US6815384B2 (en) | 2001-11-13 | 2004-11-09 | Pentax Corporation | Method for manufacturing sintered piece |
| GB2384208B (en) * | 2001-11-13 | 2005-04-06 | Pentax Corp | A method for manufacturing a sintered piece |
| US7563608B2 (en) | 2002-08-12 | 2009-07-21 | Hoya Corporation | Method for manufacturing a sintered compact for use as a cell culture base |
| JP2012149353A (en) * | 2007-03-09 | 2012-08-09 | Mitsubishi Materials Corp | Method for producing vapor deposition material |
| JP2014532030A (en) * | 2011-10-13 | 2014-12-04 | サン−ゴバン セラミック マテリアルズ アクスイェ セルスカプ | Manufacturing method of dense ceramic products based on SiC |
| CN107413280A (en) * | 2016-08-30 | 2017-12-01 | 赣州科盈结构陶瓷有限公司 | A kind of ceramic blank preparation method |
| WO2019193959A1 (en) * | 2018-04-02 | 2019-10-10 | パナソニックＩｐマネジメント株式会社 | Resin powder, sealing material, electronic component, and resin powder manufacturing method |
| JPWO2019193959A1 (en) * | 2018-04-02 | 2021-04-01 | パナソニックＩｐマネジメント株式会社 | Manufacturing method of resin powder, encapsulant, electronic parts, and resin powder |
| EP3816138A4 (en) * | 2018-06-28 | 2022-03-30 | Tokuyama Corporation | Method for producing granules for ceramic production |
| US11884596B2 (en) | 2018-06-28 | 2024-01-30 | Tokuyama Corporation | Method for producing granules for ceramic production |
| WO2023009090A3 (en) * | 2021-07-27 | 2023-04-06 | Decovi̇ta Yapi Ürünleri̇ Sanayi̇ Ve Ti̇caret Anoni̇m Şi̇rketi̇ | Reuse of spray dryer dry cyclone powders in the production process |
| CN116352057A (en) * | 2023-03-27 | 2023-06-30 | 重庆罗曼新材料科技有限公司 | ZTA ceramic particle composite wear-resistant part and preparation method thereof |
| CN117103411A (en) * | 2023-09-11 | 2023-11-24 | 苏州市伊贝高温技术材料有限公司 | Ceramic granulating powder production system, method, device and medium |
| CN117103411B (en) * | 2023-09-11 | 2024-03-01 | 苏州市伊贝高温技术材料有限公司 | Ceramic granulating powder production system, method, device and medium |
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