JPH059074A - Ceramic composite sintered body, its production and sliding member - Google Patents
Ceramic composite sintered body, its production and sliding memberInfo
- Publication number
- JPH059074A JPH059074A JP3156826A JP15682691A JPH059074A JP H059074 A JPH059074 A JP H059074A JP 3156826 A JP3156826 A JP 3156826A JP 15682691 A JP15682691 A JP 15682691A JP H059074 A JPH059074 A JP H059074A
- Authority
- JP
- Japan
- Prior art keywords
- sintered body
- silicon carbide
- silicon nitride
- porous structure
- free carbon
- 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.)
- Granted
Links
Landscapes
- Sliding-Contact Bearings (AREA)
- Mechanical Sealing (AREA)
- Ceramic Products (AREA)
- Porous Artificial Stone Or Porous Ceramic Products (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、高強度を有するととも
に摺動特性に優れ、メカニカルシールや軸受等の摺動部
材に好適な複合焼結体およびこれを用いた摺動部材に関
する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite sintered body having high strength and excellent sliding characteristics, which is suitable for sliding members such as mechanical seals and bearings, and a sliding member using the same.
【０００２】[0002]
【従来技術】炭化珪素や窒化珪素に代表される非酸化物
系セラミックスは、他のセラミックスや金属に比較し
て、硬度、強度、靱性および化学的安定性等に優れる材
料として注目され、たとえば、メカニカルシール部品、
軸受部品、薬品用バルブ部材として用いられている。2. Description of the Related Art Non-oxide ceramics typified by silicon carbide and silicon nitride are attracting attention as materials superior in hardness, strength, toughness, chemical stability, etc. as compared with other ceramics and metals. Mechanical seal parts,
Used as bearing parts and chemical valve members.
【０００３】しかしながら、窒化珪素および炭化珪素単
体では十分な摺動特性が得られないことから、窒化珪素
粉末や炭化珪素粉末に対して、焼結助剤としてＡｌ2 Ｏ
3 や周期律表第３ａ族元素酸化物、あるいは炭素および
Ｂ4 Ｃ等を添加すると同時にグラファイトやＢＮ等の固
体潤滑材を添加し、これを真空中あるいは不活性雰囲気
中で焼成することにより、窒化珪素や炭化珪素からなる
マトリックス中に前記固体潤滑材を均一分散させ、これ
によりその焼結体表面における摺動特性を高めることが
行われている。However, since silicon nitride and silicon carbide alone do not provide sufficient sliding characteristics, Al 2 O as a sintering aid for silicon nitride powder and silicon carbide powder.
3 and the Periodic Table Group 3a element oxide, or the addition of carbon and B 4 C or the like solid lubricant simultaneously as graphite or BN is added to this by firing in a vacuum or in an inert atmosphere, The solid lubricant is uniformly dispersed in a matrix made of silicon nitride or silicon carbide to improve the sliding property on the surface of the sintered body.
【０００４】[0004]
【発明が解決しようとする問題点】摺動特性を高めるた
めには、焼結体表層部における固体潤滑材の量が多い方
が望ましいが、固体潤滑材を多量に添加すると、焼結体
自体の緻密化が阻害されるとともに、いわゆる骨材とし
てのセラミックス自体の強度が低くなるために摺動部材
として割れや欠け等が生じやすくなるという問題があっ
た。そのために固体潤滑材の添加量にもおのずと制限が
あった。In order to improve the sliding characteristics, it is desirable that the amount of solid lubricant in the surface layer of the sintered body is large. However, if a large amount of solid lubricant is added, the sintered body itself There is a problem in that the densification of the ceramics is hindered and the strength of the ceramics itself, which is a so-called aggregate, is lowered, so that the sliding member is apt to be cracked or chipped. Therefore, the amount of solid lubricant added was naturally limited.
【０００５】また製法上、固体潤滑材自体の分散を均一
に行う必要があり、場合によっては焼結体内部の固体潤
滑材が焼結体の破壊源となり、強度を低下させるという
問題がある。しかも窒化珪素をマトリックスとした固体
潤滑材として分散した焼結体では、その窒化珪素結晶の
粒界に焼結助剤として添加した金属酸化物が存在するた
めに耐薬品性が悪く、その使用範囲が限定されるという
問題もある。In addition, in the manufacturing method, it is necessary to uniformly disperse the solid lubricant itself, and in some cases, the solid lubricant inside the sintered body becomes a source of destruction of the sintered body, resulting in a problem that the strength is reduced. In addition, in a sintered body in which silicon nitride is dispersed as a solid lubricant, the chemical resistance is poor because the metal oxide added as a sintering aid is present in the grain boundaries of the silicon nitride crystal, and its range of use There is also a problem that is limited.
【０００６】[0006]
【問題点を解決するための手段】本発明者等は、上記問
題点に対して検討を重ねた結果、骨材として炭化珪素を
用いた系において、炭化珪素粒子により３次元的な網目
構造よりなる多孔質組織を形成し、その炭化珪素粒子の
空隙部を窒化珪素及び炭素により充たすことにより、優
れた機械的強度と摺動特性が得られ、さらに、組織中に
分散含有させる炭素を内部よりも焼結体表層部に多く存
在させ、内部における固体潤滑材の量を小さくすること
により焼結体自体の強度を低下させることなく、表層部
における摺動性を向上することができ、これにより各種
の摺動部材として信頼性の高い安定した特性を発揮する
ことができることを見出したものである。As a result of repeated studies on the above problems, the present inventors have found that in a system using silicon carbide as an aggregate, a three-dimensional network structure is obtained by using silicon carbide particles. By forming a porous structure consisting of the above and filling the voids of the silicon carbide particles with silicon nitride and carbon, excellent mechanical strength and sliding characteristics can be obtained, and further, the carbon to be dispersed and contained in the structure is Also exists in the surface layer of the sintered body, and by reducing the amount of the solid lubricant inside, the slidability in the surface layer can be improved without lowering the strength of the sintered body itself. The inventors have found that various types of sliding members can exhibit highly reliable and stable characteristics.
【０００７】本発明は、セラミックス焼結体における摺
動特性が、焼結体の表層部の構造および組織に支配され
る特性であり、また焼結体内部は、いわゆる摺動に対す
る支持部材的な作用をなすという考え方から、摺動性を
向上させる成分である炭素等を保持する骨材部を炭化珪
素結晶を主体とする３次元的な網目構造よりなる多孔質
より形成し、その空隙部にて炭素等の固体潤滑材を保持
する構造よりなることを大きな特徴とするものである。
この骨材成分は、炭化珪素、または炭化珪素と窒化珪素
との複合体からなるもので、これらのセラミックスは、
それ自体強度が高く、また摺動特性の点において他のセ
ラミックスに比較して優れた性質を有する。According to the present invention, the sliding characteristics of the ceramic sintered body are controlled by the structure and structure of the surface layer of the sintered body, and the inside of the sintered body functions as a so-called supporting member for sliding. From the idea of acting, the aggregate that holds carbon, which is a component that improves slidability, is formed of a porous material having a three-dimensional network structure mainly composed of silicon carbide crystals, and the voids are formed in the voids. The main feature of the structure is that it holds a solid lubricant such as carbon.
The aggregate component is made of silicon carbide or a composite of silicon carbide and silicon nitride. These ceramics are
It has a high strength per se and is superior in sliding property to other ceramics.
【０００８】また、本発明によれば、摺動特性を大きく
向上させるために添加される固体潤滑材を図１に示すよ
うに、焼結体の表層部から内部にかけての固体潤滑材が
少なくなるようにしたことを特徴とする。特に焼結体内
部は、摺動特性に関与しないという観点から、実質的に
固体潤滑材が含有されていなくてもよく、骨材成分であ
る炭化珪素や窒化珪素からなることがよい。Further, according to the present invention, as shown in FIG. 1, the solid lubricant added for greatly improving the sliding property is reduced in the amount of the solid lubricant from the surface layer portion to the inside of the sintered body. It is characterized by doing so. In particular, the inside of the sintered body may not substantially contain a solid lubricant from the viewpoint that it does not contribute to sliding characteristics, and it is preferable that the inside of the sintered body be made of silicon carbide or silicon nitride that is an aggregate component.
【０００９】しかしながら、焼結体表層部から内部にか
けて、その組成や組織が急変すると、その境界部分に特
性の相違により応力が発生しやすく、割れや欠け等を生
じることがあるために、表層部より内部にかけて図１に
示すように、固体潤滑材の量は徐々に少なくなるように
構成することがよい。However, if the composition or structure of the sintered body changes abruptly from the surface layer to the inside, stress is likely to occur at the boundary portion due to the difference in characteristics, and cracks or chips may occur. As shown in FIG. 1, the amount of the solid lubricant may be gradually reduced toward the inside.
【００１０】本発明のセラミックス複合焼結体を得る方
法について説明すると、従来のように炭化珪素や窒化珪
素等の骨材成分に対して固体潤滑材粉末を混合し焼成す
る方法では、均一組織となり、本発明の構成である表層
部と内部において固体潤滑材の含有量の異なる組織は形
成されない。A method for obtaining the ceramic composite sintered body of the present invention will be described. In the conventional method of mixing solid lubricant powder with an aggregate component such as silicon carbide or silicon nitride and firing, a uniform structure is obtained. A structure having different contents of the solid lubricant is not formed between the surface layer portion and the inside, which is the configuration of the present invention.
【００１１】そこで、本発明によれば、まず原料粉末と
して炭化珪素粉末を準備する。用いる炭化珪素粉末とし
てはα−ＳｉＣ、β−ＳｉＣのいずれか、またはこれら
を混合して使用することもできる。炭化珪素粉末の平均
粒径は０．１〜２μm が適当である。また上記炭化珪素
粉末に対しては焼結助剤を添加する。焼結助剤として
は、硼素およびＢ4 Ｃ等の硼素含有化合物、ＡｌＮ等の
アルミニウム化合物、炭素あるいは焼成により炭素を生
成することのできる有機化合物等など一般に知られてい
る炭化珪素用焼結助剤が使用できる。Therefore, according to the present invention, first, silicon carbide powder is prepared as a raw material powder. The silicon carbide powder to be used may be either α-SiC or β-SiC, or a mixture thereof. The average particle size of the silicon carbide powder is suitably 0.1 to 2 μm. Further, a sintering aid is added to the silicon carbide powder. As the sintering aid, there are commonly known sintering aids for silicon carbide such as boron and boron-containing compounds such as B 4 C, aluminum compounds such as AlN, carbon or organic compounds capable of producing carbon by firing. Agents can be used.
【００１２】上記炭化珪素粉末と、場合により上記焼結
助剤を添加し、充分に混合した後、上記粉末にバインダ
ー等を添加し、周知の成形方法、たとえばプレス成形、
押出成形、鋳込み成形、冷間静水圧成形等により所望の
形状に成形する。成形体は、不活性雰囲気、真空中で仮
焼し、開気孔率の高い多孔質体とする。この多孔質体
は、炭化珪素結晶が３次元的に繋がった網目構造からな
る。The above silicon carbide powder and optionally the above sintering aid are added and mixed sufficiently, then a binder or the like is added to the above powder, and a known molding method such as press molding,
It is molded into a desired shape by extrusion molding, cast molding, cold isostatic molding, or the like. The formed body is calcined in an inert atmosphere and vacuum to obtain a porous body having a high open porosity. This porous body has a network structure in which silicon carbide crystals are three-dimensionally connected.
【００１３】次に、上記のようにして得られた多孔質体
を焼成するが、本発明によれば、この焼成を下記化１Next, the porous body obtained as described above is fired. According to the present invention, this firing is represented by the following chemical formula 1.
【００１４】[0014]
【化１】 ３ＳｉＣ＋２Ｎ2 → Ｓｉ3 Ｎ4 ＋３Ｃ
で示されるように炭化珪素と窒素の反応により窒化珪素
および炭素が生成可能な雰囲気中で焼成する。具体的に
は、１０００℃以上、特に１５００℃以上の温度にて、
雰囲気中に窒素ガスを必須成分として含むとともに該窒
素ガス圧力が５０気圧以上で焼成することにより化１の
反応を進行させることができる。## STR00001 ## As shown by 3SiC + 2N 2 → Si 3 N 4 + 3C, firing is performed in an atmosphere in which silicon nitride and carbon can be produced by the reaction of silicon carbide and nitrogen. Specifically, at a temperature of 1000 ° C or higher, particularly 1500 ° C or higher,
The reaction of Chemical formula 1 can be promoted by including nitrogen gas as an essential component in the atmosphere and firing at a nitrogen gas pressure of 50 atm or higher.
【００１５】かかる製造法において、焼成前の多孔質体
は、その開気孔率が５〜２５％程度が望ましい。これ
は、開気孔率が５％より小さいと窒化珪素および炭素の
生成が少なくなり、摺動特性が充分でなく、また、２５
％より大きいと、骨材としての強度が弱く焼結体の機械
的特性が低下し、また上記式で表される反応による窒化
珪素と炭素の生成によって空隙部が充分に充填されず、
ポアが残存し摺動特性が低下する。In such a manufacturing method, the porous body before firing preferably has an open porosity of about 5 to 25%. This is because when the open porosity is less than 5%, the production of silicon nitride and carbon is reduced, and the sliding characteristics are not sufficient.
%, The strength as an aggregate is weak and the mechanical properties of the sintered body deteriorate, and the voids are not sufficiently filled due to the formation of silicon nitride and carbon by the reaction represented by the above formula,
Pore remains and sliding characteristics deteriorate.
【００１６】この焼成によれば、窒素ガスと接する炭化
珪素表面で上記化１の反応が進み、反応により生成され
る窒化珪素および炭素により多孔質体の空隙部が充たさ
れ、表面の緻密化が進む。According to this calcination, the reaction of the above chemical formula 1 proceeds on the surface of silicon carbide in contact with nitrogen gas, the voids of the porous body are filled with silicon nitride and carbon produced by the reaction, and the surface is densified. Advances.
【００１７】また、焼結体の表層部において特に上記反
応が活発に生じるために、焼結体表層部の上記化１によ
る反応生成物、即ち、炭素と窒化珪素は内部よりも表層
部の方が多くなるという特異的焼結体が形成される。こ
れにより、表層部から内部にかけて骨材である炭化珪素
および窒化珪素の量比が変化することが挙げられ、炭化
珪素／（窒化珪素＋炭化珪素）で表される組成比は表層
部から内部にかけて大きくなる。Further, since the above reaction particularly occurs actively in the surface layer portion of the sintered body, the reaction product of the above chemical formula 1 in the surface layer portion of the sintered body, that is, carbon and silicon nitride, is more in the surface layer portion than in the inside. A peculiar sintered body is formed in which the amount is large. This may change the amount ratio of silicon carbide and silicon nitride, which are aggregates, from the surface layer portion to the inside. The composition ratio represented by silicon carbide / (silicon nitride + silicon carbide) is from the surface layer portion to the inside. growing.
【００１８】この焼結のメカニズムについては定かでは
ないが、高温高圧下の窒素雰囲気中で、炭化珪素粒子の
表面から窒化珪素への反応が進行し、それに伴い体積膨
張が生じ、それによりある程度緻密化が進行し、一旦表
層部に緻密層が生じると焼結体内部への窒素ガスの進入
が抑制されるために、結果として表層部、内部ともに気
孔率５％以下の緻密体となるものの、表層部と内部にお
いてほぼ連続的に異なる組織が形成されると考えられ
る。Although the mechanism of this sintering is not clear, in the nitrogen atmosphere under high temperature and high pressure, the reaction from the surface of the silicon carbide particles to silicon nitride proceeds, and accordingly the volume expansion occurs, which causes a certain degree of denseness. Once the formation of a dense layer in the surface layer portion is suppressed, the penetration of nitrogen gas into the inside of the sintered body is suppressed, resulting in a dense body having a porosity of 5% or less in both the surface layer portion and the inside. It is considered that different structures are formed almost continuously in the surface layer and inside.
【００１９】[0019]
【作用】本発明によれば、炭素などの固体潤滑材を保持
する骨材を炭化珪素からなる３次元的な網目構造より構
成することにより焼結体全体としての強度を高めること
ができる。また、しかも表層部における固体潤滑材であ
る炭素量を焼結体表層部のみに多く存在させることによ
り、焼結体全体としての強度を低下させることがなく、
表層部において比較的多量の炭素が存在しても内部にお
ける強度が高いことから摺動部材としても安定した摺動
特性を発揮することができる。しかも、表層部から内部
にかけての組織的な変化がほぼ連続的に形成されている
ことから、焼結体内での特性の相違により発生する応力
を低減することができる。According to the present invention, the strength of the sintered body as a whole can be increased by constructing the aggregate holding the solid lubricant such as carbon with a three-dimensional mesh structure made of silicon carbide. Further, by making a large amount of carbon, which is the solid lubricant in the surface layer portion, exist only in the surface layer portion of the sintered body, the strength of the entire sintered body is not lowered,
Even if a relatively large amount of carbon is present in the surface layer, the internal strength is high, so that stable sliding characteristics can be exhibited as a sliding member. Moreover, since the structural change from the surface layer portion to the inside is formed almost continuously, it is possible to reduce the stress generated due to the difference in characteristics in the sintered body.
【００２０】また、骨材成分である炭化珪素粒子同士が
結合した組織であるために、焼結体自体の熱伝導率を高
めることができ、これにより摺動時に発生した熱を効率
的に放熱することもできる。さらに炭素を内部において
も適量存在させることにより焼結体全体の電気抵抗を小
さくすることができ、これにより放電加工を行うことが
できる。Further, since the structure is a structure in which silicon carbide particles, which are an aggregate component, are bonded to each other, the thermal conductivity of the sintered body itself can be increased, whereby the heat generated during sliding can be efficiently radiated. You can also do it. Furthermore, the electric resistance of the entire sintered body can be reduced by allowing carbon to exist in an appropriate amount inside, and thus electric discharge machining can be performed.
【００２１】また、焼結体表層部において、化１に示さ
れる反応を進行させ、炭化珪素の骨材からなる多孔質の
空隙部に多量の窒化珪素および炭素を形成させることに
より耐熱衝撃性および靱性に優れた表層部が形成され
る。Further, in the surface portion of the sintered body, the reaction shown in Chemical formula 1 is advanced to form a large amount of silicon nitride and carbon in the porous voids made of the aggregate of silicon carbide, so that thermal shock resistance and A surface layer portion having excellent toughness is formed.
【００２２】また、通常の窒化珪素質焼結体によれば、
窒化珪素結晶粒子間に焼結助剤として用いられた金属酸
化物が粒界相として存在するが、この焼結体の表層部で
は、窒化珪素及び炭化珪素結晶粒子間に金属酸化物が実
質的に存在しないことも大きな特徴であり、耐薬品性を
高めることができ、摺動部材として適用範囲を広げるこ
とができる。According to the ordinary silicon nitride sintered body,
The metal oxide used as a sintering aid is present as a grain boundary phase between the silicon nitride crystal particles, but in the surface layer portion of this sintered body, the metal oxide is substantially present between the silicon nitride and silicon carbide crystal particles. It is also a major feature that it does not exist, and chemical resistance can be enhanced, and the application range as a sliding member can be expanded.
【００２３】[0023]
【実施例】β−ＳｉＣ粉末（平均粒径０．４μm 、酸素
含有量０．１重量％）に対して、成形用バインダーとし
てレゾール型フェノール樹脂２０％溶液を適量添加し、
さらに溶媒としてアセトンを適量添加し、混練乾燥後、
篩を通して成形用顆粒を得た。この顆粒を金型プレスを
用いて成形圧２０００ｋｇ／ｃｍ2 で外径６０ｍｍ、厚
み１０ｍｍの円板状成形体を作成した。EXAMPLE An appropriate amount of 20% resol type phenol resin solution as a molding binder was added to β-SiC powder (average particle size 0.4 μm, oxygen content 0.1% by weight).
Further, by adding an appropriate amount of acetone as a solvent, kneading and drying,
The granules for molding were obtained through a sieve. A disk-shaped molded body having an outer diameter of 60 mm and a thickness of 10 mm was prepared from the granules at a molding pressure of 2000 kg / cm 2 using a die press.
【００２４】次に成形体を所定形状に生加工した後、不
活性雰囲気（Ａｒ気流中) で２０００℃で１時間焼成し
た。この仮焼体を表１に示したＮ2 圧力、焼成温度、焼
成時間に設定し焼成を行った。Next, the green body was green-processed into a predetermined shape and then fired at 2000 ° C. for 1 hour in an inert atmosphere (Ar stream). The calcined body was fired at the N 2 pressure, firing temperature and firing time shown in Table 1.
【００２５】得られた焼結体に対して、アルキメデス法
により密度および焼結体の開気孔率を測定し、また表層
の構成相をＸ線回折測定分析にて行った。さらに焼上げ
面より０．２ｍｍ削りおとした面の摺動性評価を行っ
た。摺動特性評価は、表面をラップ仕上げしたφ５０ｍ
ｍの円板にＳＵＳII鋼球を固定ピンとして接触させ、試
料円板を回転させ、その接触負荷と摩擦力を測定するこ
とによって摩耗係数を求めた。テスト終了後、同試料の
面を用いてビッカース硬度を計測した。また、得られた
焼結体の組織を電子顕微鏡により観察し３次元的な網目
構造の有無を確認した。さらに焼結体の強度をＪＩＳＲ
１６０１により測定した。その結果を表２に示した。With respect to the obtained sintered body, the density and the open porosity of the sintered body were measured by the Archimedes method, and the constituent phase of the surface layer was analyzed by X-ray diffraction analysis. Further, the slidability of the surface scraped by 0.2 mm from the baked surface was evaluated. Sliding property evaluation is φ50m with lapped surface
The SUSII steel ball was brought into contact with a disk of m as a fixed pin, the sample disk was rotated, and the contact load and frictional force were measured to determine the wear coefficient. After the test was completed, the Vickers hardness was measured using the surface of the same sample. Further, the structure of the obtained sintered body was observed with an electron microscope to confirm the presence or absence of a three-dimensional network structure. Furthermore, the strength of the sintered body is determined by JISR.
Measured according to 1601. The results are shown in Table 2.
【００２６】次に、比較例として、β−ＳｉＣ粉末（平
均粒径０．４μm ）１００重量部にＢ4 Ｃ粉末を０．４
重量部添加混合する以外は前記の方法と全く同様にして
成形体を作成し、その後、２０５０℃で真空中で１時間
焼成を行い、緻密な炭化珪素質焼結体を作成し、前記と
同様に各種特性の測定および摺動評価を行った（表中、
試料Ｎo,１）。Next, as a comparative example, 0.4 part of B 4 C powder was added to 100 parts by weight of β-SiC powder (average particle size 0.4 μm).
Except for adding and mixing parts by weight, a molded body is prepared in exactly the same manner as described above, and thereafter, it is fired in vacuum at 2050 ° C. for 1 hour to prepare a dense silicon carbide-based sintered body, which is the same as above. Various characteristics were measured and sliding evaluation was performed (in the table,
Sample No, 1).
【００２７】また、表中、試料Ｎo,３に対して、表面か
ら内部への組成分布を測定し、炭化珪素と窒化珪素との
組成分布ならび硬度分布を図１に、炭素量の変化を図２
に示した。Further, in the table, the composition distribution from the surface to the interior was measured for the sample No. 3, and the composition distribution and hardness distribution of silicon carbide and silicon nitride are shown in FIG. Two
It was shown to.
【００２８】[0028]
【表１】 [Table 1]
【００２９】[0029]
【表２】 [Table 2]
【００３０】表１および表２によれば、従来の炭化珪素
からなる焼結体では、摺動特性として摩擦係数は０．４
〜０．５であるのに対して、本発明品はいずれも摩擦係
数が０．２以下のレベルを達成することができ、いずれ
の焼結体のＪＩＳＲ１６０１による抗折強度を測定した
ところ、４０ｋｇ／ｍｍ2 以上が達成された。According to Tables 1 and 2, the conventional sintered body made of silicon carbide has a friction coefficient of 0.4 as sliding characteristics.
In contrast, the products of the present invention can achieve a coefficient of friction of 0.2 or less, and the bending strength according to JIS R1601 of any of the sintered products was 40 kg. / Mm 2 or more was achieved.
【００３１】また、図１および図２によれば、焼結体表
面部で炭素および窒化珪素が内部よりも多量に存在して
いることがわかる。また、硬度分布によれば、焼結体表
面部は内部よりもわずかに硬度が低く、表面より０．５
ｍｍ付近に硬度の最大となる部位が存在することがわか
る。Further, according to FIGS. 1 and 2, it is understood that carbon and silicon nitride are present in a larger amount on the surface portion of the sintered body than in the inside. Further, according to the hardness distribution, the hardness of the surface of the sintered body is slightly lower than that of the inside,
It can be seen that there is a portion having the maximum hardness near mm.
【００３２】[0032]
【発明の効果】以上詳述した通り、本発明のセラミック
ス複合焼結体は、高強度を有しつつその表面の摩擦係数
が非常に小さいものであり、それにより、メカニカルシ
ールや軸受等の摺動部材への適用において優れた摺動特
性が発揮されるとともに部材の長寿命化を図ることがで
きる。As described in detail above, the ceramic composite sintered body of the present invention has a high strength and a very small coefficient of friction on the surface thereof. When applied to a dynamic member, excellent sliding characteristics are exhibited and the life of the member can be extended.
【図１】本発明のセラミックス複合焼結体の表層部から
の深さに対する炭化珪素および窒化珪素の組成分布およ
び硬度分布を示す図である。FIG. 1 is a diagram showing a composition distribution and a hardness distribution of silicon carbide and silicon nitride with respect to a depth from a surface layer portion of a ceramics composite sintered body of the present invention.
【図２】本発明のセラミックス複合焼結体の表層部から
の深さに対する炭素分布を示す図である。FIG. 2 is a diagram showing carbon distribution with respect to depth from the surface layer portion of the ceramic composite sintered body of the present invention.
Claims (4)
離炭素からなり、前記炭化珪素が３次元的に繋がった多
孔質組織をなし、且つ該多孔質組織の空隙部が窒化珪素
および遊離炭素により占められていることを特徴とする
セラミック複合焼結体。1. A porous structure composed of at least silicon carbide, silicon nitride and free carbon, said silicon carbide forming a three-dimensionally connected structure, and voids of said porous structure are occupied by silicon nitride and free carbon. A ceramic composite sintered body characterized in that
離炭素の量が内部より多い組成からなる請求項１記載の
セラミック複合焼結体。2. The ceramic composite sintered body according to claim 1, wherein the surface layer portion of the sintered body has a composition in which the amounts of silicon nitride and free carbon are larger than those in the interior.
活性雰囲気で焼結し、多孔質組織の炭化珪素質焼結体を
得た後、該焼結体を炭化珪素が窒化する窒素ガス圧力下
で加圧熱処理し、前記多孔質組織の空隙部に窒化珪素お
よび遊離炭素を析出させたことを特徴とするセラミック
複合焼結体の製法。3. A sintered body containing silicon carbide powder as a main component is sintered in an inert atmosphere to obtain a silicon carbide-based sintered body having a porous structure, and thereafter, the nitrogen is used to nitride the sintered body with silicon carbide. A method for producing a ceramic composite sintered body, which comprises subjecting silicon nitride and free carbon to precipitation in a void portion of the porous structure under pressure heat treatment under gas pressure.
硼素及び／又はアルミニウムの炭化物及び／または窒化
物、ならびに遊離炭素を分散含有するとともに、前記炭
化珪素質結晶が３次元的に繋がった多孔質組織をなし、
且つ該多孔質組織の空隙部が窒化珪素および遊離炭素に
より占められたセラミック複合焼結体よりなる摺動部
材。4. Silicon carbide and silicon nitride as main components,
Carbide and / or nitride of boron and / or aluminum, and free carbon are dispersedly contained, and a porous structure in which the silicon carbide crystals are three-dimensionally connected is formed,
A sliding member made of a ceramic composite sintered body in which voids of the porous structure are occupied by silicon nitride and free carbon.
Priority Applications (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3156826A JP2784280B2 (en) | 1991-06-27 | 1991-06-27 | Ceramic composite sintered body, method for producing the same, and sliding member |
| EP19920101552 EP0497345B1 (en) | 1991-01-31 | 1992-01-30 | Composite ceramic sintered material, process for producing the same, and slider member using the same |
| DE69223528T DE69223528T2 (en) | 1991-01-31 | 1992-01-30 | Sintered, ceramic composite material, process for its production and the same slide valve |
| US08/162,796 US5462813A (en) | 1991-01-31 | 1993-12-07 | Composite ceramic sintered material |
| US08/466,930 US5571611A (en) | 1991-01-31 | 1995-06-06 | Composite ceramic sintered material and slider member using the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3156826A JP2784280B2 (en) | 1991-06-27 | 1991-06-27 | Ceramic composite sintered body, method for producing the same, and sliding member |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH059074A true JPH059074A (en) | 1993-01-19 |
| JP2784280B2 JP2784280B2 (en) | 1998-08-06 |
Family
ID=15636197
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3156826A Expired - Fee Related JP2784280B2 (en) | 1991-01-31 | 1991-06-27 | Ceramic composite sintered body, method for producing the same, and sliding member |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2784280B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1059652C (en) * | 1994-12-28 | 2000-12-20 | 住友电气工业株式会社 | Silicon nitride sinter and process for producing the same |
-
1991
- 1991-06-27 JP JP3156826A patent/JP2784280B2/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1059652C (en) * | 1994-12-28 | 2000-12-20 | 住友电气工业株式会社 | Silicon nitride sinter and process for producing the same |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2784280B2 (en) | 1998-08-06 |
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