JPH0952771A - Hexagonal boron nitride sintered compact and its production - Google Patents
Hexagonal boron nitride sintered compact and its productionInfo
- Publication number
- JPH0952771A JPH0952771A JP7203297A JP20329795A JPH0952771A JP H0952771 A JPH0952771 A JP H0952771A JP 7203297 A JP7203297 A JP 7203297A JP 20329795 A JP20329795 A JP 20329795A JP H0952771 A JPH0952771 A JP H0952771A
- Authority
- JP
- Japan
- Prior art keywords
- density
- powder
- hexagonal
- purity
- boron nitride
- 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
- PZNSFCLAULLKQX-UHFFFAOYSA-N Boron nitride Chemical compound N#B PZNSFCLAULLKQX-UHFFFAOYSA-N 0.000 title claims description 7
- 238000004519 manufacturing process Methods 0.000 title claims description 7
- 229910052582 BN Inorganic materials 0.000 title claims description 5
- 238000005452 bending Methods 0.000 claims abstract description 16
- 238000005245 sintering Methods 0.000 claims abstract description 16
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 10
- 239000001301 oxygen Substances 0.000 claims abstract description 10
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 10
- 239000002994 raw material Substances 0.000 claims description 9
- 238000000465 moulding Methods 0.000 claims description 3
- 239000000843 powder Substances 0.000 abstract description 30
- 230000000704 physical effect Effects 0.000 abstract description 2
- 238000000034 method Methods 0.000 description 10
- 238000009694 cold isostatic pressing Methods 0.000 description 9
- 238000002156 mixing Methods 0.000 description 4
- 239000000919 ceramic Substances 0.000 description 3
- 239000012535 impurity Substances 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 238000005336 cracking Methods 0.000 description 2
- 238000000354 decomposition reaction Methods 0.000 description 2
- 238000010304 firing Methods 0.000 description 2
- 238000007731 hot pressing Methods 0.000 description 2
- 238000010902 jet-milling Methods 0.000 description 2
- 238000007088 Archimedes method Methods 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 238000007696 Kjeldahl method Methods 0.000 description 1
- 238000007792 addition Methods 0.000 description 1
- 229910000272 alkali metal oxide Inorganic materials 0.000 description 1
- 229910000287 alkaline earth metal oxide Inorganic materials 0.000 description 1
- 229910052810 boron oxide Inorganic materials 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 230000008094 contradictory effect Effects 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- JKWMSGQKBLHBQQ-UHFFFAOYSA-N diboron trioxide Chemical compound O=BOB=O JKWMSGQKBLHBQQ-UHFFFAOYSA-N 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000011049 filling Methods 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 239000011810 insulating material Substances 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000003472 neutralizing effect Effects 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 238000013001 point bending Methods 0.000 description 1
- 238000001272 pressureless sintering Methods 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 229910001404 rare earth metal oxide Inorganic materials 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 230000035939 shock Effects 0.000 description 1
- 238000001256 steam distillation Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
Landscapes
- Ceramic Products (AREA)
- Press-Shaping Or Shaping Using Conveyers (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、高純度、高密度、
高曲げ強度の六方晶窒化ほう素焼結体及びその製造法に
関する。TECHNICAL FIELD The present invention relates to high purity, high density,
The present invention relates to a high bending strength hexagonal boron nitride sintered body and a method for producing the same.
【０００２】六方晶窒化ほう素（ｈ−ＢＮ）は、高耐熱
性、高熱伝導性、高耐熱衝撃性、高電気絶縁性など優れ
た特性を有し、また数少ない易加工性のセラミックスで
あることから、セラミックス焼結用るつぼ、耐熱用治
具、高温絶縁材として用いられているが、自己焼結性が
ないので他の一般的なセラミックスに比べて機械的強度
が小さく、利用が拡大しない一原因となっている。Hexagonal boron nitride (h-BN) has excellent characteristics such as high heat resistance, high thermal conductivity, high thermal shock resistance, and high electric insulation, and is a few easily processable ceramics. Therefore, it is used as a crucible for ceramics sintering, a heat-resistant jig, and a high-temperature insulating material. However, it has less mechanical strength than other general ceramics because it does not have self-sinterability, and its use is not expanded. It is the cause.
【０００３】[0003]
【従来の技術】従来、ｈ−ＢＮ焼結体用のｈ−ＢＮ粉の
評価は、例えば粒度、比表面積、不純物含有量などで行
われているが、その評価結果とｈ−ＢＮ焼結体の特性、
例えば焼結体密度、曲げ強度、ＢＮ純度などとの間には
あまり相関が認められず、実験と経験に頼らざるを得な
かった。2. Description of the Related Art Conventionally, evaluation of h-BN powder for h-BN sintered compacts has been performed by, for example, particle size, specific surface area, content of impurities, etc. Characteristics of
For example, there was no significant correlation between the sintered body density, bending strength, BN purity, etc., and it was necessary to rely on experiments and experience.
【０００４】ｈ−ＢＮ焼結体は、ｈ−ＢＮ粉に焼結助剤
を添加し、ＣＩＰ後常圧焼結するか、又はホットプレ
ス、ＨＩＰなどによって製造されている。焼結助剤とし
ては、アルカリ金属酸化物、アルカリ土類金属酸化物、
ほう素酸化物、希土類酸化物などが用いられているが、
これらの添加によってＢＮ純度が低くなり不純物による
汚染、耐熱性の低下、絶縁破壊などを引き起こすので、
焼結助剤の使用はできるけ少なくすることが望まれてい
る。The h-BN sintered body is manufactured by adding a sintering aid to the h-BN powder and subjecting it to pressureless sintering after CIP, or by hot pressing, HIP or the like. As a sintering aid, an alkali metal oxide, an alkaline earth metal oxide,
Boron oxide, rare earth oxide, etc. are used,
These additions lower the BN purity and cause contamination with impurities, lower heat resistance, dielectric breakdown, etc.
It is desirable to use as little sintering aid as possible.
【０００５】そこで、本出願人は、焼結助剤を添加せず
に高純度でかつ高強度のｈ−ＢＮ焼結体を製造する方法
として、ｈ−ＢＮ粉末原料として粗粉ｈ−ＢＮと微粉ｈ
−ＢＮを混合し、成形後、常圧焼結する方法を先に提案
した（特願平６−１０６９１２号明細書）が、この方法
によっても焼結体密度が低く、ＢＮ純度も９９. ５％未
満であり十分ではなかった。Therefore, as a method for producing a high-purity and high-strength h-BN sintered body without adding a sintering aid, the applicant of the present invention used coarse powder h-BN as a raw material for h-BN powder. Fine powder h
Although a method of mixing -BN, molding and then sintering under normal pressure was previously proposed (Japanese Patent Application No. 6-106912), the density of the sintered body is low and the BN purity is 99.5 even by this method. %, Which was not sufficient.
【０００６】[0006]
【発明が解決しようとする課題】本発明の目的は、ｈ−
ＢＮ焼結体の相反する純度、密度、強度特性を、ＢＮ純
度９９．５重量％以上、密度１．８５ｇ／ｃｍ3 以上、
常温曲げ強度４０ＭＰａ以上を発現させたｈ−ＢＮ焼結
体及びその製造法を提供することにある。The object of the present invention is to obtain h-
The contradictory purity, density and strength characteristics of the BN sintered body are as follows: BN purity 99.5% by weight or more, density 1.85 g / cm 3 or more,
An object of the present invention is to provide an h-BN sintered body that exhibits a room temperature bending strength of 40 MPa or more, and a method for manufacturing the same.
【０００７】[0007]
【課題を解決する手段】本発明者らは、前記課題を解決
するために鋭意検討した結果、ｈ−ＢＮ粉末原料とし
て、 酸素含有量０．５〜１．６重量％以下であり、圧
力２７００ｋｇ／ｃｍ2 で冷間静水圧（ＣＩＰ）成形し
た場合の成形体密度が１．９５ｇ／ｃｍ3以上となる充
填性の大なるものを用いればよいこと見いだし、本発明
を完成させたものである。Means for Solving the Problems As a result of intensive studies for solving the above-mentioned problems, the present inventors have found that the h-BN powder raw material has an oxygen content of 0.5 to 1.6 wt% or less and a pressure of 2700 kg. The inventors have found that it is sufficient to use a material having a high filling property such that the density of the molded body is 1.95 g / cm 3 or more in the case of cold isostatic pressing (CIP) molding / cm 2 , and the present invention has been completed. .
【０００８】すなわち、本発明は、ＢＮ純度９９．５重
量％以上、密度１．８５ｇ／ｃｍ3以上、常温曲げ強度
４０ＭＰａ以上であることを特徴とするｈ−ＢＮ焼結
体、及び圧力２７００ｋｇ／ｃｍ2 下におけるＣＩＰ成
形体密度が１．９５ｇ／ｃｍ3以上となるｈ−ＢＮ粉を
含み酸素含有量０．５〜１．６重量％以下であるｈ−Ｂ
Ｎ粉末原料を成形した後、温度１４００〜２４００℃で
焼結することを特徴とするｈ−ＢＮ焼結体の製造法であ
る。That is, the present invention has an BN purity of 99.5% by weight or more, a density of 1.85 g / cm 3 or more, and a room temperature bending strength of 40 MPa or more, and an h-BN sintered body, and a pressure of 2700 kg /. hB having an oxygen content of 0.5 to 1.6% by weight or less including h-BN powder having a CIP compact density of 1.95 g / cm 3 or more under cm 2.
It is a method for producing an h-BN sintered body, which is characterized in that N powder raw material is molded and then sintered at a temperature of 1400 to 2400 ° C.
【０００９】[0009]
【発明の実施の形態】以下、更に詳しく本発明について
説明する。本発明において、ｈ−ＢＮ焼結体のＢＮ純
度、密度及び常温曲げ強度を上記のように限定した理由
は以下のとおりである。BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. In the present invention, the reasons for limiting the BN purity, density and room temperature bending strength of the h-BN sintered body as described above are as follows.
【００１０】ＢＮ純度が９９．５重量％未満では、Ｂ2
Ｏ3 、焼結助剤、Ｂ2 Ｏ3 と焼結助剤との複塩、焼結助
剤の分解物などの不純物によって汚染され、ｈ−ＢＮ焼
結体本来の諸特性が劣化し機械加工性も低下する。ＢＮ
純度は、ｈ−ＢＮをアルカリ分解後ケルダール法による
水蒸気蒸留を行い、留出液中の全窒素を中和適定するこ
とによって測定することができる。If the BN purity is less than 99.5% by weight, B 2
It is contaminated by impurities such as O 3 , sintering aid, double salt of B 2 O 3 and sintering aid, decomposition products of sintering aid, etc. Workability is also reduced. BN
The purity can be measured by subjecting h-BN to alkaline decomposition, steam distillation by the Kjeldahl method, and neutralizing the total nitrogen in the distillate.
【００１１】密度が１．８５ｇ／ｃｍ3 未満では、相対
密度が８０％未満となり、空隙の多い焼結体組織となっ
てｈ−ＢＮ焼結体本来の優れた物性が低下する。密度は
アルキメデス法によって測定することができる。If the density is less than 1.85 g / cm 3 , the relative density will be less than 80%, resulting in a sintered body structure with many voids, which deteriorates the original excellent physical properties of the h-BN sintered body. The density can be measured by the Archimedes method.
【００１２】常温曲げ強度が４０ＭＰａ未満では、取扱
い時又は加工時の割れ、クラックを引き起こす。常温曲
げ強度はＪＩＳ Ｒ１６０１の三点曲げ強さ試験に準じ
て測定することができる。If the room-temperature bending strength is less than 40 MPa, cracking or cracking occurs during handling or processing. The room-temperature bending strength can be measured according to JIS R1601 three-point bending strength test.
【００１３】本発明のｈ−ＢＮ焼結体は次のようにして
製造することができる。まず、原料ｈ−ＢＮ粉末として
は、圧力２７００ｋｇ／ｃｍ2 下におけるＣＩＰ成形体
密度が１．９５ｇ／ｃｍ3 以上となるｈ−ＢＮ粉を含み
酸素含有量が０．５〜１．６重量％以下である粉末が使
用される。このようなｈ−ＢＮ粉末原料は、圧力２７０
０ｋｇ／ｃｍ2 下におけるＣＩＰ成形体密度が１．９５
ｇ／ｃｍ3 以上で酸素含有量１．６重量％以上のｈ−Ｂ
Ｎ粉に酸素含有量１．６重量％未満のｈ−ＢＮ粉を混合
する方法、圧力２７００ｋｇ／ｃｍ2 下におけるＣＩＰ
成形体密度１．９５ｇ／ｃｍ3 以上で酸素含有量１．６
重量％未満のｈ−ＢＮ粉に酸素含有量１．６重量％以上
のｈ−ＢＮ粉を混合する方法などによって入手すること
ができる。混合には振動ミル、ボールミル、リボンブレ
ンダーなどが用いられる。The h-BN sintered body of the present invention can be manufactured as follows. First, the raw material h-BN powder contains h-BN powder having a CIP compact density of 1.95 g / cm 3 or more under a pressure of 2700 kg / cm 2 and an oxygen content of 0.5 to 1.6% by weight. The following powders are used. Such an h-BN powder raw material has a pressure of 270.
CIP compact density under 0 kg / cm 2 is 1.95.
h-B with g / cm 3 or more and an oxygen content of 1.6 wt% or more
Method of mixing N-powder with h-BN powder having an oxygen content of less than 1.6% by weight, CIP under a pressure of 2700 kg / cm 2 .
Oxygen content 1.6 at a density of 1.95 g / cm 3 or more
It can be obtained by a method of mixing h-BN powder of less than wt% with h-BN powder of oxygen content of 1.6 wt% or more. A vibration mill, a ball mill, a ribbon blender or the like is used for mixing.
【００１４】本発明で使用される圧力２７００ｋｇ／ｃ
ｍ2 下におけるＣＩＰ成形体密度１．９５ｇ／ｃｍ3 以
上となるｈ−ＢＮ粉は、普通一般に入手される市販のｈ
−ＢＮ粉をジェットミル粉砕することによって得ること
ができる。このようなＣＩＰ成形体密度を示すｈ−ＢＮ
粉は、ｈ−ＢＮ粉末原料中に３５重量％以上（１００重
量％を含む）含まれていることが好ましく、３５重量％
未満ではｈ−ＢＮ焼結体の密度が１．８５ｇ／ｃｍ3 以
上とはならない。Pressure used in the present invention 2700 kg / c
h-BN powder having a CIP compact density of 1.95 g / cm 3 or more under m 2 is a commercially available h-BN powder.
It can be obtained by jet milling BN powder. H-BN showing such CIP compact density
The powder preferably contains 35% by weight or more (including 100% by weight) in the h-BN powder raw material, and 35% by weight.
If it is less than 1, the density of the h-BN sintered body will not be 1.85 g / cm 3 or more.
【００１５】本発明において、ｈ−ＢＮ粉末原料の酸素
含有量が１．６重量％をこえるとｈ−ＢＮ焼結体のＢＮ
純度が９９．５重量％未満となり、また０．５重量％未
満では焼結が起こらず、常温曲げ強度４０ＭＰａ以上の
ｈ−ＢＮ焼結体を製造することが困難となる。In the present invention, when the oxygen content of the h-BN powder raw material exceeds 1.6% by weight, the BN of the h-BN sintered body is
If the purity is less than 99.5% by weight, and if less than 0.5% by weight, sintering does not occur and it becomes difficult to manufacture an h-BN sintered body having a room temperature bending strength of 40 MPa or more.
【００１６】焼結方法としては一般的な焼結方法、例え
ばホットプレス法、常圧焼結法、ＨＩＰ法などを採用す
ることができる。焼成温度は１４００℃〜２４００℃が
好ましく、１４００℃未満では焼結が不十分となって常
温曲げ強度が低下し、また２４００℃をこえるとｈ−Ｂ
Ｎが気化又は異常粒成長を起こし、常温曲げ強度が低下
する。As a sintering method, a general sintering method, for example, a hot pressing method, an atmospheric pressure sintering method, a HIP method or the like can be adopted. The firing temperature is preferably 1400 ° C to 2400 ° C, and if the temperature is less than 1400 ° C, the sintering is insufficient and the room temperature bending strength is lowered.
N vaporizes or abnormally grows grains, and the room-temperature bending strength decreases.
【００１７】[0017]
【実施例】以下、実施例、比較例をあげて更に具体的に
本発明を説明する。 実施例１〜７ 比較例１〜５ 市販のｈ−ＢＮ粉又はそれをジェットミル粉砕してなる
（ａ）〜（ｇ）の７種のｈ−ＢＮ粉を準備し、それらに
ついて圧力２７００ｋｇ／ｃｍ2 下におけるＣＩＰ成形
体密度を測定した。その結果を表１に示す。次いで、こ
れらのｈ−ＢＮ粉を種々混合してｈ−ＢＮ粉末原料を調
製し、それを黒鉛製ダイスに充填し、圧力２００ｋｇ／
ｃｍ2 、表２に示す焼成温度で１ｈｒ保持しホットプレ
スを行った。得られたｈ−ＢＮ焼結体について、ＢＮ純
度、密度及び常温曲げ強度を測定した。それらの結果を
表２に示す。EXAMPLES The present invention will be described more specifically with reference to Examples and Comparative Examples. Examples 1 to 7 Comparative Examples 1 to 5 Commercially available h-BN powder or 7 types of h-BN powder (a) to (g) prepared by jet milling the h-BN powder was prepared, and the pressure was 2700 kg / cm. The CIP compact density under 2 was measured. Table 1 shows the results. Next, various kinds of these h-BN powders are mixed to prepare an h-BN powder raw material, which is filled in a graphite die, and the pressure is 200 kg /
It was held for 1 hour at a firing temperature of 2 cm 2 in Table 2 and hot pressed. With respect to the obtained h-BN sintered body, BN purity, density and room temperature bending strength were measured. Table 2 shows the results.
【００１８】[0018]
【表１】 [Table 1]
【００１９】[0019]
【表２】 [Table 2]
【００２０】[0020]
【発明の効果】本発明によれば、ＢＮ純度９９．５重量
％以上、密度１．８５ｇ／ｃｍ3 以上、常温曲げ強度４
０ＭＰａ以上の高純度、高密度、高曲げ強度のｈ−ＢＮ
焼結体が提供される。According to the present invention, the BN purity is 99.5% by weight or more, the density is 1.85 g / cm 3 or more, and the room temperature bending strength is 4
High purity, high density, high bending strength h-BN of 0 MPa or more
A sintered body is provided.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 中村 美幸 福岡県大牟田市新開町１ 電気化学工業株 式会社大牟田工場内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Miyuki Nakamura 1 Shinkaimachi, Omuta City, Fukuoka Prefecture Omuta Plant, an electric chemical industry company
Claims (2)
８５ｇ／ｃｍ3 以上、常温曲げ強度４０ＭＰａ以上であ
ることを特徴とする六方晶窒化ほう素焼結体。1. A BN purity of 99.5% by weight or more and a density of 1.
A hexagonal boron nitride sintered body having a bending strength at room temperature of not less than 85 g / cm 3 and not less than 40 MPa.
ＩＰ成形体密度が１．９５ｇ／ｃｍ3 以上となる六方晶
窒化ほう素粉を含み酸素含有量０．５〜１．６重量％以
下である六方晶窒化ほう素粉末原料を成形した後、温度
１４００〜２４００℃で焼結することを特徴とする六方
晶窒化ほう素焼結体の製造法。 2. C under a pressure of 2700 kg / cm 2 .
After molding a hexagonal boron nitride powder raw material containing an hexagonal boron nitride powder having an IP compact density of 1.95 g / cm 3 or more and an oxygen content of 0.5 to 1.6 wt% or less, A method for producing a hexagonal boron nitride sintered body, which comprises sintering at 1400 to 2400 ° C.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP20329795A JP3688022B2 (en) | 1995-08-09 | 1995-08-09 | Hexagonal boron nitride sintered body |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP20329795A JP3688022B2 (en) | 1995-08-09 | 1995-08-09 | Hexagonal boron nitride sintered body |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0952771A true JPH0952771A (en) | 1997-02-25 |
| JP3688022B2 JP3688022B2 (en) | 2005-08-24 |
Family
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| Application Number | Title | Priority Date | Filing Date |
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| JP20329795A Expired - Fee Related JP3688022B2 (en) | 1995-08-09 | 1995-08-09 | Hexagonal boron nitride sintered body |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102992769A (en) * | 2012-12-13 | 2013-03-27 | 山东理工大学 | Preparation method of h-BN/TaC machinable ceramic |
| CN103406072A (en) * | 2013-08-28 | 2013-11-27 | 郑州中南杰特超硬材料有限公司 | Hexagonal boron nitride powder column molding process and rubber mold used therein |
| CN106316404A (en) * | 2016-08-22 | 2017-01-11 | 赵烨程 | Cubic boron nitride ceramic material and preparation method thereof |
-
1995
- 1995-08-09 JP JP20329795A patent/JP3688022B2/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102992769A (en) * | 2012-12-13 | 2013-03-27 | 山东理工大学 | Preparation method of h-BN/TaC machinable ceramic |
| CN103406072A (en) * | 2013-08-28 | 2013-11-27 | 郑州中南杰特超硬材料有限公司 | Hexagonal boron nitride powder column molding process and rubber mold used therein |
| CN106316404A (en) * | 2016-08-22 | 2017-01-11 | 赵烨程 | Cubic boron nitride ceramic material and preparation method thereof |
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| Publication number | Publication date |
|---|---|
| JP3688022B2 (en) | 2005-08-24 |
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