JPS63101519A - Rolling body made of ceramics - Google Patents
Rolling body made of ceramicsInfo
- Publication number
- JPS63101519A JPS63101519A JP61245312A JP24531286A JPS63101519A JP S63101519 A JPS63101519 A JP S63101519A JP 61245312 A JP61245312 A JP 61245312A JP 24531286 A JP24531286 A JP 24531286A JP S63101519 A JPS63101519 A JP S63101519A
- Authority
- JP
- Japan
- Prior art keywords
- pts
- approximate
- silicon nitride
- powder
- rolling 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.)
- Granted
Links
- 239000000919 ceramic Substances 0.000 title claims abstract description 27
- 238000005096 rolling process Methods 0.000 title claims abstract description 22
- 229910052581 Si3N4 Inorganic materials 0.000 claims abstract description 13
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 claims abstract description 13
- 238000005245 sintering Methods 0.000 claims abstract description 12
- 239000000843 powder Substances 0.000 claims abstract description 11
- 239000000463 material Substances 0.000 claims abstract description 6
- 239000002245 particle Substances 0.000 claims description 5
- 239000011148 porous material Substances 0.000 claims description 5
- 239000011261 inert gas Substances 0.000 claims description 2
- 238000000034 method Methods 0.000 abstract description 14
- 239000000203 mixture Substances 0.000 abstract description 3
- 239000011230 binding agent Substances 0.000 abstract description 2
- 239000013078 crystal Substances 0.000 abstract description 2
- SIWVEOZUMHYXCS-UHFFFAOYSA-N oxo(oxoyttriooxy)yttrium Chemical compound O=[Y]O[Y]=O SIWVEOZUMHYXCS-UHFFFAOYSA-N 0.000 abstract description 2
- 239000002904 solvent Substances 0.000 abstract description 2
- PNEYBMLMFCGWSK-UHFFFAOYSA-N Alumina Chemical compound [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 abstract 3
- 229910052782 aluminium Inorganic materials 0.000 abstract 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 abstract 1
- 238000004898 kneading Methods 0.000 abstract 1
- 238000012360 testing method Methods 0.000 description 7
- 238000001272 pressureless sintering Methods 0.000 description 5
- 230000000052 comparative effect Effects 0.000 description 4
- 238000007731 hot pressing Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 238000005238 degreasing Methods 0.000 description 2
- 229910001873 dinitrogen Inorganic materials 0.000 description 2
- 238000009661 fatigue test Methods 0.000 description 2
- 238000005498 polishing Methods 0.000 description 2
- 239000007921 spray Substances 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 1
- PMHQVHHXPFUNSP-UHFFFAOYSA-M copper(1+);methylsulfanylmethane;bromide Chemical compound Br[Cu].CSC PMHQVHHXPFUNSP-UHFFFAOYSA-M 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000007723 die pressing method Methods 0.000 description 1
- 239000010410 layer Substances 0.000 description 1
- 239000011812 mixed powder Substances 0.000 description 1
- 150000004767 nitrides Chemical class 0.000 description 1
- 238000009659 non-destructive testing Methods 0.000 description 1
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
Landscapes
- Rolling Contact Bearings (AREA)
- Ceramic Products (AREA)
Abstract
Description
【発明の詳細な説明】
［発明の目的］
（産業上の利用分野）
本発明は、セラミックス製転動体に係り、さらに詳しく
は耐圧強度に優れ、寿命のバラツキの少ないセラミック
ス製転動体に関する。DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a ceramic rolling element, and more particularly to a ceramic rolling element that has excellent pressure resistance and less variation in life.
（従来の技術）
近年、ベアリングの転動体であるボールやローラーの材
質として、耐熱性や耐摩耗性に優れ、また軽くて剛性の
大きい窒化ケイ素焼結体等のセラミックス部材の使用が
試みられており、特に高温下で使用されるベアリング用
部材として期待されている。(Prior art) In recent years, attempts have been made to use ceramic members such as silicon nitride sintered bodies, which have excellent heat resistance and wear resistance, are lightweight and have high rigidity, as materials for balls and rollers that are the rolling elements of bearings. Therefore, it is expected to be used as a member for bearings, especially those used under high temperatures.
このようなベアリング用のセラミックス部材としては、
通常の常圧焼結によるものでは内部のポアサイズが大き
く耐圧強度が不足するため、ホットプレス法により形成
したものが使用されている。Ceramic members for such bearings include:
Since the normal pressureless sintering method has large internal pores and lacks pressure resistance, those formed by hot pressing are used.
（発明が解決しようとする問題点）
しかしながらホットプレス法によるセラミック８製の転
動体でも、５〜８μｍの内部ボアが点在しており、一般
にセラミックスの破壊強度がボア等の内部欠陥が大きく
なるほど弱くなるといわれている事からも、まだ不十分
であり、さらにホブトプレス法は１軸加圧のなめ得られ
る焼結体が配向性を持ち、このため機械的特性にたいし
て異方性を有するため、ある方向からの荷重に対して脆
いという欠点があり、寿命のバラツキが大きいという問
題があった。(Problem to be Solved by the Invention) However, even in rolling elements made of Ceramic 8 made by the hot pressing method, internal bores of 5 to 8 μm are scattered, and in general, the fracture strength of ceramics increases as internal defects such as bores become larger. It is still insufficient, as it is said that the hobto press method weakens the material.Furthermore, the hobto press method is uniaxially pressurized, and the resulting sintered compact has orientation, and therefore has anisotropy in mechanical properties. It has the disadvantage of being brittle against loads from any direction, and has the problem of large variations in service life.
またホットプレス法により転動体、例えばボールを形成
するには、ポットプレス法による成形体の形状が単純な
形に限定されているので、まず平板状に成形し、これを
棒状に切断し、さらに丸棒に加工した後、各々のボール
の近似形状まで加工してからバレル研磨等により最終形
状に仕上げている。このように、ホットプレス法による
セラミックス焼結体からの転動体の形成は、加工コスト
が大きくなり生産性が悪いという問題もあった。In addition, in order to form rolling elements, such as balls, by the hot press method, the shape of the molded object by the pot press method is limited to a simple shape, so it is first formed into a flat plate shape, then cut into rod shapes, and then After being processed into a round bar, each ball is processed into an approximate shape and then finished into the final shape by barrel polishing. As described above, the formation of rolling elements from ceramic sintered bodies by the hot pressing method has the problem of high processing costs and poor productivity.
そこで、最終形状の近似形状に成形でき加工コストの小
さい常圧焼結法によるセラミックス転動体で、ホットプ
レス法によるものと同等もしくはそれ以上の耐圧強度を
有するものが強く望まれていた。Therefore, there has been a strong desire for a ceramic rolling element produced by pressureless sintering that can be formed into a shape that approximates the final shape, has low processing costs, and has a compressive strength equal to or greater than that produced by hot pressing.
本発明はこのような従来の問題を解決するためになされ
たもので、どのような方向からの荷重に対してもほぼ均
等な耐圧強度を有し、寿命のバラツキが少なく、さらに
加工コストの小さいセラミックス製転動体を提供するこ
とを目的とする。The present invention was made to solve these conventional problems, and has almost uniform pressure resistance against loads from any direction, less variation in life, and lower processing costs. The purpose is to provide a ceramic rolling element.
（問題点を解決するための手段）
本発明のセラミックス製転動体は、内部のポアサイズが
３μｍ以下で、かつ結晶組織が配向性を持たない窒化ゲ
イ素材からなることを特徴としている。(Means for Solving the Problems) The ceramic rolling element of the present invention is characterized by having an internal pore size of 3 μm or less and being made of a gay nitride material whose crystal structure has no orientation.
すなわち本発明のセラミックス製転動体は、セラミック
ス焼結体の製造プロセスのうち、常圧焼結と等方加圧焼
結（ＨＩＰ）の組合わせにおいて、各製造条件をコント
ロールすることにより得られ、例えば以下のようにして
製造することができる。That is, the ceramic rolling element of the present invention is obtained by controlling each manufacturing condition in a combination of pressureless sintering and isostatic pressure sintering (HIP) among the manufacturing processes of ceramic sintered bodies, For example, it can be manufactured as follows.
まず窒化ケイ素粉末に適量の焼結助剤を添加して混合粉
砕した後、例えばスプレードライヤー法により造粒する
。この造粒粉の粒径は５０〜１００μｍの範囲が好まし
く、１００μｍを越えると焼結後の内部の空隙が大きく
なってしまい、また５０μｍより小さくてもそれ以上の
効果は得られない。First, an appropriate amount of sintering aid is added to silicon nitride powder, mixed and pulverized, and then granulated by, for example, a spray dryer method. The particle size of this granulated powder is preferably in the range of 50 to 100 μm; if it exceeds 100 μm, internal voids will become large after sintering, and if it is smaller than 50 μm, no further effect will be obtained.
次いで金型プレス法やラバープレス法等により転動体の
最終形状の近似形状に成形する。この成形体を脱脂後常
圧焼結し、次いで不活性ガス雰囲気、例えば窒素ガス雰
囲気中で等方加圧焼結処理を行い、処理体をバレル研磨
等の加工により最終形状に仕上げる。ここで等方加圧焼
結処理の温度条件としては、高いほど内部の空隙は小さ
くなるがあまり高いと表層部に異質層が生じ耐圧強度が
低下することがあり、またあまり低いとこの効果が不十
分なので、１５００℃〜１８００℃の範囲が好ましい。Next, it is molded into a shape that approximates the final shape of the rolling element by a mold press method, a rubber press method, or the like. After degreasing, this molded body is sintered under normal pressure, and then subjected to isostatic pressure sintering treatment in an inert gas atmosphere, for example, a nitrogen gas atmosphere, and the treated body is finished into a final shape by processing such as barrel polishing. Here, as for the temperature conditions for isotropic pressure sintering treatment, the higher the temperature, the smaller the internal voids will be. However, if the temperature is too high, a heterogeneous layer may be formed on the surface layer, reducing the pressure resistance, and if the temperature is too low, this effect will be reduced. Since this is insufficient, a range of 1500°C to 1800°C is preferred.
また圧力は１０〜２０００ｋＯ／ ｃぜ、好ましくは３
００〜１０００ｋ（１／ｃぜの範囲である。The pressure is 10 to 2000 kO/c, preferably 3
The range is 00 to 1000k (1/cze).
（作用）
本発明のセラミックス製転動体において、内部のポアサ
イズが３μｍ以下なので、耐圧強度に優れており、また
常圧焼結を用いているので得られた焼結体が配向性を持
たず、このため実質的に等方性を有しており、どのよう
な方向に対してもほぼ均等な耐圧強度を示す。(Function) In the ceramic rolling element of the present invention, the internal pore size is 3 μm or less, so it has excellent pressure resistance, and since pressureless sintering is used, the obtained sintered body does not have orientation. Therefore, it has substantially isotropy, and exhibits almost uniform compressive strength in any direction.
なお、ここで言う等方性とは、外圧に対する強度が方向
によって異ならないことである。Note that isotropy here means that the strength against external pressure does not differ depending on the direction.
（実施例） 次に本発明の実施例について説明する。(Example) Next, examples of the present invention will be described.
実施例１
まず窒化ケイ素（Ｓｉ３ Ｎ ４ ）粉末１００重呈部
に対して、焼結助剤として酸化イツトリウム５重量部と
酸化アルミニウム４重量部と窒化アルミニウム３重量部
とを加え、平均粒径が１．０μｍ以下になるようにボー
ルミルで十分に粉砕、混合を行い、この混合粉末に有機
バインダ５重量部と適量の溶剤を加え混練し、スプレー
ドライヤー法により平均造粒粉粒径が約７０μｍとなる
ように造粒した。Example 1 First, 5 parts by weight of yttrium oxide, 4 parts by weight of aluminum oxide, and 3 parts by weight of aluminum nitride as sintering aids were added to 100 parts by weight of silicon nitride (Si3N4) powder, and the average particle size was Thoroughly pulverize and mix with a ball mill so that the particle size is 1.0 μm or less. 5 parts by weight of an organic binder and an appropriate amount of solvent are added and kneaded to this mixed powder, and the average granulated powder particle size is approximately 70 μm using a spray dryer method. It was granulated so that
次いでこの造粒粉を用いてプレス圧１０００ｋｐ／ｃｄ
で金型プレスにより図面（ａ）に示す形状に成形した。Next, using this granulated powder, a press pressure of 1000kp/cd was applied.
It was molded into the shape shown in drawing (a) using a mold press.
この成形体を脱脂した後、窒素ガス雰囲気中で約１８０
０°Ｃ１４時間で常圧焼結を行い、次いで窒素ガス１０
００ｋ（１／ａｊ、約１７００°Ｃ１４０分の条件下で
等方加圧焼結処理を行った。After degreasing this molded body, approximately 180
Normal pressure sintering was performed at 0°C for 14 hours, and then nitrogen gas was sintered for 10 hours.
Isostatic pressure sintering treatment was performed under the conditions of 00k (1/aj), approximately 1700° C., and 140 minutes.
この窒化ケイ素焼結体をバレル研磨により直径１０ｎｍ
のベアリング用ボールを形成した。This silicon nitride sintered body was barrel polished to a diameter of 10 nm.
A ball for a bearing was formed.
実施例２〜４
実施例１と同一の窒化ケイ素粉末を用いて、表に示す製
造条件以外は実施例１と同一条件でセラミックス製ボー
ルをそれぞれ形成した。なお乾式ラバープレスを用いた
場合の成形体の形状を図面（ｂ）に示す。Examples 2 to 4 Using the same silicon nitride powder as in Example 1, ceramic balls were formed under the same conditions as in Example 1 except for the manufacturing conditions shown in the table. Note that the shape of the molded product when using a dry rubber press is shown in drawing (b).
比較例
また本発明との比較のため、従来のホットプレス法を用
いてプレス圧約１０００に！７／ａａ、温度約１８００
℃の条件で平板状の窒化ケイ素焼結体を成形し、これよ
り切出し加工およびバレル研磨加工により実施例と同一
形状のセラミックス製ボールを形成した。Comparative Example Also, for comparison with the present invention, a conventional hot press method was used with a press pressure of about 1000! 7/aa, temperature approximately 1800
A flat silicon nitride sintered body was molded under conditions of 0.degree.
このようにして得た実施例１〜４および比較例のセラミ
ックス製ボールの内部を非破壊検査により調べたところ
実施例１〜４のセラミックス製ボールはいずれも内部に
２〜３μｍのボアが数個存在していただけに対し。て、
比較例のセラミックス製ボールは表層部および内部共に
３〜８μｍのボアが点在していた。When the interiors of the ceramic balls of Examples 1 to 4 and Comparative Examples thus obtained were examined by non-destructive testing, the ceramic balls of Examples 1 to 4 all had several 2-3 μm bores inside. For just existing. hand,
The ceramic ball of the comparative example had bores of 3 to 8 μm scattered both on the surface and inside.
また実施例１〜４および比較例のセラミックス製ボール
を用いて圧砕試験と転がり疲労試験を下記の方法により
行った。各々の試験結果を表に示す。Further, using the ceramic balls of Examples 1 to 4 and Comparative Example, a crushing test and a rolling fatigue test were conducted in the following manner. The results of each test are shown in the table.
（圧砕試験）
ＪＩＳ−８−１５０１に準じ、インストロン万能試験機
によりクロスヘッドスピード５薗／分で圧砕強度を測定
し、最大接触圧力として示す。(Crushing test) According to JIS-8-1501, the crushing strength was measured using an Instron universal testing machine at a crosshead speed of 5 mm/min, and is shown as the maximum contact pressure.
（転がり疲労試験）
スラスト型軸受試験機を用いて５ＩＪＪ板上で３個のセ
ラミックス製ボールを回転させ、試験開始から２００時
間までを１００ ｋｌＪ、２００時間以降を２５０ ｋ
ｇの荷重を加えて試験を行った。(Rolling fatigue test) Three ceramic balls were rotated on a 5IJJ board using a thrust type bearing testing machine, and the test was conducted at 100 klJ for the first 200 hours and at 250 kl for the 200th hour onward.
The test was conducted by applying a load of 100 g.
（以下余白）
［発明の効果コ
以上説明したように本発明によれば、内部のポアサイズ
が３μｍ以下セ、実質”的に等方性の窒化ケイ素焼結体
を使用しているので、全方向に対してほぼ均等な優れた
耐圧強度を有しており、寿命が長くバラツキの少ないセ
ラミックス製転動体が得られる。(Blank below) [Effects of the Invention] As explained above, according to the present invention, a substantially isotropic silicon nitride sintered body with an internal pore size of 3 μm or less is used. Ceramic rolling elements can be obtained that have excellent pressure resistance that is almost equal to that of the ceramics, and have a long life and little variation.
また従来のホットプレス法によるものに比べ、常圧焼結
を使用しているので成形体の形状を最終形状の近似形状
とすることが出来るので加工コストを短縮することも出
来る。Furthermore, compared to the conventional hot press method, since pressureless sintering is used, the shape of the molded body can be approximated to the final shape, so processing costs can be reduced.
図面（ａ）は本発明の一実施例の金型プレスによる成形
体の形状、（ｂ）は乾式ラバープレスによる成形体の形
状である。Drawing (a) shows the shape of a molded body formed by die pressing according to an embodiment of the present invention, and (b) shows the shape of a molded body formed by dry rubber pressing.
Claims (4)
が実質的に等方性の窒化ケイ素材からなることを特徴と
するセラミックス製転動体。(1) A ceramic rolling element characterized by being made of a silicon nitride material with an internal pore size of 3 μm or less and a substantially isotropic grain boundary structure.
してなる特許請求の範囲第１項記載のセラミックス製転
動体。(2) The ceramic rolling element according to claim 1, wherein the silicon nitride material is obtained by isostatically sintering a pressureless sintered body.
ケイ素造粒粉を使用してなる特許請求の範囲第２項記載
のセラミックス製転動体。(3) The ceramic rolling element according to claim 2, wherein the pressureless sintered body is formed using silicon nitride granulated powder having an average particle size of 50 to 100 μm.
０〜１８００℃および１０〜２０００ｋｇ／ｃｍ＾２で
施されている特許請求の範囲第２項記載のセラミックス
製転動体。(4) Isostatic pressure sintering in an inert gas atmosphere at 150
The ceramic rolling element according to claim 2, which is coated at 0 to 1800°C and 10 to 2000 kg/cm^2.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61245312A JP2549636B2 (en) | 1986-10-17 | 1986-10-17 | Ceramics rolling elements |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61245312A JP2549636B2 (en) | 1986-10-17 | 1986-10-17 | Ceramics rolling elements |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63101519A true JPS63101519A (en) | 1988-05-06 |
| JP2549636B2 JP2549636B2 (en) | 1996-10-30 |
Family
ID=17131799
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61245312A Expired - Lifetime JP2549636B2 (en) | 1986-10-17 | 1986-10-17 | Ceramics rolling elements |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2549636B2 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02124771A (en) * | 1988-07-27 | 1990-05-14 | Ngk Spark Plug Co Ltd | Silicon nitride-base sintered body for rolling bearing material and its production |
| US5002907A (en) * | 1987-11-26 | 1991-03-26 | Ngk Insulators, Ltd. | Homogenous silicon nitride sintered body |
| JP2008279604A (en) * | 2007-05-08 | 2008-11-20 | Universal Trim Supply Co | Date code imprinting system |
| JP2011093789A (en) * | 2009-09-30 | 2011-05-12 | Hitachi Metals Ltd | Ceramic ball stock sphere, mold for forming ceramic ball stock sphere and method for manufacturing ceramic ball stock sphere |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS4952205A (en) * | 1972-06-16 | 1974-05-21 | ||
| JPS54107914A (en) * | 1978-02-10 | 1979-08-24 | Tokyo Shibaura Electric Co | Production of high density silicon nitride base sintered body |
| JPS5771872A (en) * | 1980-10-20 | 1982-05-04 | Kobe Steel Ltd | Manufacture of high density silicon nitride sintered body |
| JPS6018620A (en) * | 1984-04-27 | 1985-01-30 | Toray Ind Inc | Ball for bearing use |
-
1986
- 1986-10-17 JP JP61245312A patent/JP2549636B2/en not_active Expired - Lifetime
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS4952205A (en) * | 1972-06-16 | 1974-05-21 | ||
| JPS54107914A (en) * | 1978-02-10 | 1979-08-24 | Tokyo Shibaura Electric Co | Production of high density silicon nitride base sintered body |
| JPS5771872A (en) * | 1980-10-20 | 1982-05-04 | Kobe Steel Ltd | Manufacture of high density silicon nitride sintered body |
| JPS6018620A (en) * | 1984-04-27 | 1985-01-30 | Toray Ind Inc | Ball for bearing use |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5002907A (en) * | 1987-11-26 | 1991-03-26 | Ngk Insulators, Ltd. | Homogenous silicon nitride sintered body |
| JPH02124771A (en) * | 1988-07-27 | 1990-05-14 | Ngk Spark Plug Co Ltd | Silicon nitride-base sintered body for rolling bearing material and its production |
| JP2008279604A (en) * | 2007-05-08 | 2008-11-20 | Universal Trim Supply Co | Date code imprinting system |
| JP2011093789A (en) * | 2009-09-30 | 2011-05-12 | Hitachi Metals Ltd | Ceramic ball stock sphere, mold for forming ceramic ball stock sphere and method for manufacturing ceramic ball stock sphere |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2549636B2 (en) | 1996-10-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JPH0147428B2 (en) | ||
| JPH0774103B2 (en) | High hardness silicon nitride sintered body | |
| RU2402507C2 (en) | Ceramic material and preparation method thereof | |
| US5472919A (en) | β-silicon nitride sintered body | |
| JPS63101519A (en) | Rolling body made of ceramics | |
| JPH02141466A (en) | Ceramic composite material and production thereof | |
| JP3538524B2 (en) | Ceramic rolling element and method of manufacturing the same | |
| JP2736387B2 (en) | Silicon nitride-based sintered body for rolling bearing material and method for producing the same | |
| US6136738A (en) | Silicon nitride sintered body with region varying microstructure and method for manufacture thereof | |
| JPH0526585A (en) | Jig for sintering ceramics formed body | |
| EP0648717A2 (en) | Reaction sintered ceramics and method of producing the same | |
| IL44318A (en) | Alumina carbide ceramic material | |
| US7132061B2 (en) | Electroconductive silicon nitride based composite sintered body and method for preparation thereof | |
| JPS63206359A (en) | Highly minute thermally hydrostatic sintering silicon nitride sintered body and manufacture | |
| JPS63151680A (en) | High-strength normal pressure-sintering silicon nitride sintered body and manufacture | |
| JPH0283264A (en) | Production of silicon nitride ceramics and ceramics ball for ball mill used for the same production | |
| JPS6374963A (en) | Silicon nitride base sintered body for antiabrasive material | |
| JPH06116072A (en) | Heat treatment of silicon nitride-silicon carbide composite sintered compact | |
| KR960011355B1 (en) | Sintered oxide ceramics and method of making the said ceramics | |
| JP2000319071A (en) | Grinding/dispersion media and their production | |
| JPH01164759A (en) | Aluminous sintered body and its production | |
| JPH01141875A (en) | Homogeneous silicon nitride sintered body and its manufacture | |
| JPS63170254A (en) | Manufacture of ceramics | |
| JPH0375505B2 (en) | ||
| JPH06166569A (en) | Production of sintered silicon nitride |