JP2590413B2 - Method for producing translucent high-purity cubic boron nitride sintered body - Google Patents
Method for producing translucent high-purity cubic boron nitride sintered bodyInfo
- Publication number
- JP2590413B2 JP2590413B2 JP1300587A JP30058789A JP2590413B2 JP 2590413 B2 JP2590413 B2 JP 2590413B2 JP 1300587 A JP1300587 A JP 1300587A JP 30058789 A JP30058789 A JP 30058789A JP 2590413 B2 JP2590413 B2 JP 2590413B2
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- sintered body
- cbn
- pressure
- temperature
- boron nitride
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Description
【発明の詳細な説明】 （産業上の利用分野） 本発明は、焼結助剤を全く用いない静的超高圧法によ
り、透光性高純度立方晶窒化ほう素焼結体を製造する方
法に関するものである。Description: TECHNICAL FIELD The present invention relates to a method for producing a translucent high-purity cubic boron nitride sintered body by a static ultra-high pressure method without using any sintering aid. Things.
（従来の技術及び解決しようとする課題） 立方晶窒化ほう素（以下、「cBN」と略称する）は、
ダイヤモンドに次ぐ硬度を有すると共に、化学的にも、
熱的にも極めて安定な物質である。(Conventional technology and problems to be solved) Cubic boron nitride (hereinafter abbreviated as “cBN”)
Along with hardness next to diamond, also chemically,
It is a very thermally stable substance.
このように優れた性質を有するcBN結晶は、一般に、
六方晶窒化ほう素（以下、「hBN」と略称する）に触媒
を加え、静的高圧法により、5GPa以上、1500℃以上の条
件下で合成されているが、現在の技術では、大型のcBN
単結晶を安定に合成することは非常に困難である。A cBN crystal having such excellent properties is generally
A catalyst is added to hexagonal boron nitride (hereinafter abbreviated as "hBN") and synthesized under the conditions of 5 GPa or more and 1500 ° C or more by the static high-pressure method.
It is very difficult to stably synthesize a single crystal.
そこで、cBN微結晶に金属や、炭化物、窒化物、酸化
物等の焼結助剤を相当量添加し、cBN焼結体を静的高圧
法により工業生産、工具材料、その他の用途に市販され
ている。このcBN焼結体は、焼結助剤を相当量含有する
ため、cBN単結晶に比較して、その硬さ、熱伝導等の性
質が劣っている。Therefore, a considerable amount of sintering aids such as metals, carbides, nitrides and oxides are added to the cBN microcrystals, and the cBN sintered body is marketed for industrial production, tool materials and other uses by the static high pressure method. ing. Since this cBN sintered body contains a considerable amount of a sintering aid, its properties such as hardness and heat conduction are inferior to cBN single crystal.
しかし、cBN本来の性質に近い焼結体としては、焼結
助剤の量を極めて少なくするか、焼結助剤を全く含有し
ない物であることが望ましい。However, as a sintered body close to the intrinsic properties of cBN, it is desirable that the amount of the sintering aid is extremely small or that the sintering aid does not contain any sintering aid.
従来、このような焼結体を意図した製造方法として
は、 hBNのホットプレス焼結体にMg3B2N4の触媒を拡散含浸
させたものを高温高圧処理する方法（特公昭60−28782
号公報）、 触媒を使用せずに低結晶性hBN粉末を出発物質として
高温高圧条件下（好ましい処理条件：圧力6GPa以上、温
度1450〜1600℃）で処理する方法（「マテリアルス・リ
サーチ・ブルチン」Vol.17（1972）、p.999〜1004）、 気相から析出させた熱分解窒化ほう素（パイロリティ
ックボロンナイトライド、以下「pBN」と略称する）を
高温高圧条件下（好ましい処理条件：圧力6.5GPa以上、
温度2100〜2500℃）で処理する方法（特開昭54−33510
号公報）、等が知られている。Conventionally, as a manufacturing method intended for such a sintered body, a method in which a hot press sintered body of hBN is diffused and impregnated with a catalyst of Mg 3 B 2 N 4 is subjected to high temperature and high pressure treatment (Japanese Patent Publication No. 60-28782).
), A method in which low-crystalline hBN powder is used as a starting material and treated under high-temperature and high-pressure conditions (preferable processing conditions: pressure of 6 GPa or more, temperature of 1450 to 1600 ° C) without using a catalyst (“Materials Research Bulltin Vol. 17 (1972), pp. 999-1004), pyrolytic boron nitride (pyrotic boron nitride, hereinafter abbreviated as "pBN") deposited from the gas phase under high-temperature and high-pressure conditions (preferred processing conditions). : Pressure 6.5 GPa or more,
(2100-2500 ° C.)
Publication), and the like.
しかしながら、以下に考察するとおり、これらの製造
方法にはそれぞれ問題があり、これらの方法によって得
られるcBN焼結体は、未だcBNの特性を十分に発揮してい
るとは云い難い。However, as discussed below, each of these production methods has a problem, and it is difficult to say that the cBN sintered body obtained by these methods still sufficiently exhibits the properties of cBN.
まず、前記の方法の場合、優れている点は、比較的
穏やかな高温高圧条件で透光性cBN焼結体が合成可能で
あり、得られたcBN焼結体は高熱伝導性であること等で
ある。しかし、この方法で合成されたcBN焼結体は、焼
結助剤に用いたMg3B2N4などが焼結体中に少量残留する
という欠点がある。すなわち、この残留焼結助剤が高温
条件下において、cBN→hBN交換の触媒として働くため、
焼結体の機械的、熱的性質の著しい低下が高温条件下に
おいて生じ易い。出発物質に焼結助剤を使用し、焼結助
剤を焼結体中に全く残留させないような技術は、高温高
圧焼結法では、現在まで開発されていない。First, in the case of the above method, the advantage is that a translucent cBN sintered body can be synthesized under relatively mild high-temperature and high-pressure conditions, and the obtained cBN sintered body has high thermal conductivity. It is. However, the cBN sintered body synthesized by this method has a disadvantage that a small amount of Mg 3 B 2 N 4 used as a sintering aid remains in the sintered body. In other words, this residual sintering aid works as a catalyst for cBN → hBN exchange under high temperature conditions,
A remarkable decrease in the mechanical and thermal properties of the sintered body is likely to occur under high temperature conditions. A technique that uses a sintering aid as a starting material and does not leave the sintering aid in the sintered body at all has not been developed in the high-temperature and high-pressure sintering method.
そこで、焼結助剤を全く使用せずに、hBN又はpBNを出
発物質として用い、hBN、pBN→cBN直接変換反応を利用
した反応焼結法によりcBN焼結体を合成する方法が、前
記及びの焼結体製造法である。これらの製造方法で
得られるcBN焼結体は、前記の方法で得られる焼結体
に比較し、高温条件下でのcBN→hBN変換が起こりにくい
利点がある。これは、焼結助剤を含有しないことが主な
理由と考えられる。しかし、これらの、の方法で
は、得られるcBN焼結体は灰色半透明から黒色不透明で
あり、透光性焼結体は得られない。Therefore, a method of synthesizing a cBN sintered body by a reaction sintering method using hBN or pBN → cBN direct conversion reaction without using any sintering aid and using hBN or pBN as a starting material, Is a method for producing a sintered body. The cBN sintered body obtained by these production methods has an advantage that cBN → hBN conversion under high temperature conditions does not easily occur as compared with the sintered body obtained by the above method. This is mainly because the sintering aid is not contained. However, according to these methods, the resulting cBN sintered body is translucent from gray to black and opaque, and a translucent sintered body cannot be obtained.
本発明は、上記従来技術の欠点を解消し、高温条件下
での耐熱性に優れた透光性高純度cBN焼結体を製造し得
る方法を提供することを目的とするものである。An object of the present invention is to solve the above-mentioned drawbacks of the prior art and to provide a method capable of producing a translucent high-purity cBN sintered body having excellent heat resistance under high-temperature conditions.
（課題を解決するための手段） 本発明者らは、前記、の方法に着目し、これらの
方法で得られるcBN焼結体は、焼結助剤を含有しないた
めに高温条件下で安定であるものの、透光性を示さない
ので、この原因について検討した結果、cBN粒子間に僅
かな空隙が存在するか、cBN粒子間の直接結合が少ない
ことに起因して透光性が得られないという結論に達し
た。これらの問題点を解決すれば、焼結助剤を全く使用
しないで、高温条件下で十分使用可能な透光性高純度cB
N焼結体が合成可能であるとの知見を得た。(Means for Solving the Problems) The present inventors have focused on the above methods, and the cBN sintered body obtained by these methods is stable under high temperature conditions because it does not contain a sintering aid. Although it does not show translucency, as a result of examining the cause, it is not possible to obtain translucency due to the existence of slight voids between cBN particles or few direct bonds between cBN particles I came to the conclusion. If these problems are solved, translucent high-purity cB that can be sufficiently used under high temperature conditions without using any sintering aid
We have found that N sintered compacts can be synthesized.
この知見に基づいて、本発明者らは、高温高圧焼結法
について更に研究を重ね、ここに本発明をなしたもので
ある。Based on this finding, the present inventors have further studied the high-temperature and high-pressure sintering method, and have made the present invention.
すなわち、本発明は、酸素含有量が0.06wt％以下のhB
Nを、cBNの熱力学的安定条件下の7GPa以上の圧力及び21
00℃以上の温度で、焼結助剤を用いず、不純物を前記六
方晶窒化ほう素に混入させることなく高温高圧焼結する
ことを特徴とする透光性高純度立方晶窒化ほう素焼結体
の製造法を要旨とするものである。That is, the present invention relates to an hB having an oxygen content of 0.06 wt% or less.
N at a pressure above 7 GPa under thermodynamic stability conditions of cBN and 21
A translucent high-purity cubic boron nitride sintered body characterized in that high-temperature and high-pressure sintering is performed at a temperature of 00 ° C. or higher without using a sintering agent and without mixing impurities into the hexagonal boron nitride. The gist of the method is that of
以下に本発明を更に詳述する。 Hereinafter, the present invention will be described in more detail.
（作用） 本発明に用いる出発物質のhBNは、粉末又は焼結体の
いずれでもよく、高純度のものであることが好ましい。(Action) The starting material hBN used in the present invention may be either a powder or a sintered body, and is preferably of high purity.
但し、出発物質の酸素含有量が0.06wt％以下のものを
用いる必要がある。出発物質の酸素含有量が0.06wt％よ
り多いと、透光性のcBN焼結体が得られない。However, it is necessary to use a starting material having an oxygen content of 0.06% by weight or less. If the oxygen content of the starting material is more than 0.06 wt%, a translucent cBN sintered body cannot be obtained.
そのためには、例えば、市販の高純度hBN粉末や焼結
体を出発物質として用いて、真空中、1600℃×２時間の
処理後、窒素ガス中、2100℃×２時間以上の処理をす
る。この処理により、出発物質の酸素含有量を0.06wt％
以下にすることができる。For this purpose, for example, using a commercially available high-purity hBN powder or a sintered body as a starting material, a treatment is performed in vacuum at 1600 ° C. × 2 hours, followed by a treatment in nitrogen gas at 2100 ° C. × 2 hours or more. This treatment reduces the oxygen content of the starting material to 0.06 wt%
It can be:
次いで、得られた高純度hBN粉末又は焼結体（出発物
質）を高温高圧処理する。この高温高圧処理の条件は、
cBNの熱力学的安定条件下で、7GPa以上の圧力、2100℃
以上の温度とする必要があり、焼結助剤は全く不要であ
る。この圧力条件は、タリウム、バリウム及びビスマス
の室温下で圧力により誘起される相転移を各々3.7GPa、
5.5GPa、7.7GPaの圧力定点とし、作製した荷重−圧力曲
線の関係に基づくものである。また、温度条件は、所定
の圧力下で、白金・ロジウム（6wt％）−白金・ロジウ
ム（30wt％）熱電対を用い、1800℃まで測定し、電力対
温度の関係を予め求め、この関係の外挿から1800℃以上
の温度での電力を推定し、電力制御により、透光性cBN
焼結体の得られる温度を求めたものである。Next, the obtained high-purity hBN powder or sintered body (starting material) is subjected to high-temperature and high-pressure treatment. The conditions for this high-temperature and high-pressure treatment are as follows:
Under the thermodynamic stability condition of cBN, pressure over 7GPa, 2100 ℃
It is necessary to keep the above temperature, and no sintering aid is required at all. This pressure condition is such that the pressure-induced phase transition of thallium, barium and bismuth at room temperature is 3.7 GPa, respectively.
Pressure fixed points of 5.5 GPa and 7.7 GPa are used, and based on the produced load-pressure curve relationship. The temperature conditions were measured under a predetermined pressure using a platinum-rhodium (6 wt%)-platinum-rhodium (30 wt%) thermocouple up to 1800 ° C., and the relationship between power and temperature was determined in advance. Estimate the power at temperatures above 1800 ° C from extrapolation, and control the light transmission cBN
It is the temperature at which a sintered body can be obtained.
本発明方法の実施には、高温高圧装置が必要である
が、例えば、本出願人が先に提案したベルト型高圧装置
（特願平１−186106）が使用できる。このベルト型高圧
装置は、第１図に示す構成であって、8GPa領域の圧力で
常用することが可能である。To carry out the method of the present invention, a high-temperature and high-pressure device is required. For example, a belt-type high-pressure device previously proposed by the present applicant (Japanese Patent Application No. 1-186106) can be used. This belt-type high-pressure device has the configuration shown in FIG. 1 and can be used at a pressure in the range of 8 GPa.
第１図中、（１）はゴム製Ｏリング、（２）は成形ガ
スケット、（３）はパイロフィライトガスケット、
（４）はステンレス板、（５）は通電リング、（６）は
NaCl−10wt％ZrO2からなる圧力媒体、（７）はZrO2焼結
体、（８）はMo板である。この圧力媒体（６）の内に試
料部（９）が配置される。In FIG. 1, (1) is a rubber O-ring, (2) is a molded gasket, (3) is a pyrophyllite gasket,
(4) is a stainless steel plate, (5) is an energizing ring, and (6) is
A pressure medium composed of NaCl-10 wt% ZrO 2 , (7) is a ZrO 2 sintered body, and (8) is a Mo plate. The sample part (9) is arranged in the pressure medium (6).
この試料部（９）の構成は、第２図に示すように、黒
鉛ヒーター（10）と、外側Taカプセル（111）と、内側T
aカプセル（112）とを有し、hBN試料（12）を充填した
内側Taカプセル（112）がNaCl−10wt％ZrO2又はNaCl−2
0wt％ZrO2からなる圧力媒体（６）、（13）に充填され
ている。As shown in FIG. 2, the structure of the sample section (9) is a graphite heater (10), an outer Ta capsule (11 1 ), and an inner T capsule.
and a a capsule (11 2), the inner Ta capsules filled with hBN sample (12) (11 2) of NaCl-10 wt% ZrO 2, or NaCl-2
It is filled with pressure media (6) and (13) made of 0 wt% ZrO 2 .
この高圧装置を使用した実験の一例を以下に示す。ま
ず、第２図に示す試料構成を用い、酸素含有量0.06wt％
のhBN焼結体を7GPa、2100℃の条件で高温高圧処理し
た。なお、温度は前述の1800℃までの電力対温度の関係
を外挿して電力制御により求めたものである。その結
果、透光性cBN焼結体が得られた。この焼結体をＸ線回
折で調べたところ、cBN以外の回折線は全く認められな
かった。また、試料断面をエネルギー分散型のEPMAで調
べたが、Ta等の重元素は全く認められなかった。この透
光性cBN焼結体は、非常に高純度であることが確認され
た。An example of an experiment using this high-pressure device is shown below. First, using the sample configuration shown in FIG. 2, the oxygen content was 0.06 wt%.
Was subjected to high temperature and high pressure treatment at 7 GPa and 2100 ° C. The temperature was obtained by power control by extrapolating the above-mentioned relationship between power and temperature up to 1800 ° C. As a result, a translucent cBN sintered body was obtained. When this sintered body was examined by X-ray diffraction, no diffraction lines other than cBN were observed. The cross section of the sample was examined with an energy dispersive EPMA, but no heavy elements such as Ta were found. It was confirmed that the translucent cBN sintered body had a very high purity.
なお、第２図の試料構成で重要なことは、NaCl−ZrO2
圧力媒体からの試料へのNaClの混入を完全に遮蔽するこ
とである。この点は他の高圧高温焼結の場合も同様に配
慮すべき事柄である。第２図の場合は、hBN焼結体（試
料）をTaカプセルに入れ、0.4GPaの圧力で密閉し、更に
その外側をTa箔で包んである。この遮蔽が十分でない
と、決して透光性のcBN焼結体は得られない。Ｘ線回折
により検出されない程度のNaClが混入しても、cBN焼結
体に空隙が多くなり、cBN粒子の粒成長が顕著になる。
その結果、hBN→cBN変換反応は完全に進行するが、決し
て透光性cBN焼結体は得られない。The important thing about the sample configuration of FIG. 2 is that NaCl-ZrO 2
The purpose is to completely block the intrusion of NaCl into the sample from the pressure medium. This point is a matter to be considered in the case of other high pressure and high temperature sintering as well. In the case of FIG. 2, the hBN sintered body (sample) is placed in a Ta capsule, sealed at a pressure of 0.4 GPa, and the outside thereof is wrapped with a Ta foil. If this shielding is not sufficient, a translucent cBN sintered body will never be obtained. Even if NaCl is mixed in such an amount that it cannot be detected by X-ray diffraction, voids increase in the cBN sintered body, and the grain growth of cBN particles becomes remarkable.
As a result, the hBN → cBN conversion reaction proceeds completely, but a translucent cBN sintered body is never obtained.
また、第２図に示したものと同様の試料構成を用い、
6.5GPa、2100℃の条件で、酸素含有量0.06wt％のhBN焼
結体を処理した。得られた試料は、cBNに完全に変換し
ていたが、透光性焼結体は得られなかった。このことか
らも、透光性高純度cBN焼結体の合成には、6.5GPaより
も高い圧力条件下で、2100℃以上の焼結温度が必要であ
ることが確認された。Further, using the same sample configuration as that shown in FIG. 2,
An hBN sintered body having an oxygen content of 0.06 wt% was treated under the conditions of 6.5 GPa and 2100 ° C. Although the obtained sample was completely converted to cBN, a translucent sintered body was not obtained. This also confirms that the synthesis of a translucent high-purity cBN sintered body requires a sintering temperature of 2100 ° C. or more under a pressure condition higher than 6.5 GPa.
（実施例） 次に本発明の実施例を示すが、前述の実験例も本発明
の実施例足り得ることは云うまでもない。(Example) Next, an example of the present invention will be described. However, it goes without saying that the above-mentioned experimental example is also sufficient for the example of the present invention.
実施例１ 酸素含有量0.06wt％のhBN焼結体を第２図に示す試料
構成にし、第１図に示す高圧装置を使用して7.7GPa、21
50℃の条件で30分間処理した。回収した試料は完全にTa
で覆われていた。Example 1 An hBN sintered body having an oxygen content of 0.06 wt% was made into a sample configuration shown in FIG. 2, and 7.7 GPa, 21
The treatment was performed at 50 ° C. for 30 minutes. The collected sample is completely Ta
Was covered with.
このTaを研削除去後、光学顕微鏡観察したところ、異
常粒成長の全く認められない均質な焼結体であった。After the removal of this Ta by grinding, observation under an optical microscope revealed that it was a homogeneous sintered body in which no abnormal grain growth was observed at all.
この焼結体の裏面に文字が貼り付け、透過光で写真撮
影したところ、焼結体の下地の文字が焼結体を通しては
っきりと読むことができた。この焼結体の厚さは0.7mm
であり、その色は淡緑色であった。また、この焼結体の
赤外線スペクトルを250〜4000cm-1波数領域で測定した
ところ、1000〜2200cm-1の領域を除き、光を透過してい
た。When letters were attached to the back surface of the sintered body and photographed with transmitted light, the letters on the base of the sintered body could be clearly read through the sintered body. The thickness of this sintered body is 0.7mm
And its color was light green. When the infrared spectrum of this sintered body was measured in the wave number region of 250 to 4000 cm −1 , light was transmitted except for the region of 1000 to 2200 cm −1 .
また、Ｘ線回折により焼結体を調べた結果、cBNの回
折線以外の回折線は全く認められなかった。また、焼結
体の一部を切断研磨し、EPMAで調べたところ、Ta、Na、
Zrは全く検出されなかった。Further, as a result of examining the sintered body by X-ray diffraction, no diffraction line other than the diffraction line of cBN was observed at all. Also, when a part of the sintered body was cut and polished and examined by EPMA, Ta, Na,
No Zr was detected.
更に、焼結体の破面をSEM観察したところ、第３図に
示すように粒界のはっきりしない緻密な組織の焼結体で
あった。焼結体を溶融NaOHでエッチングし、粒径を調べ
た結果、２〜５μｍの粒子からなる均質焼結体であっ
た。また、焼結体のビッカース硬さは、荷重2kgで測定
したところ、50GPa以上であった。Further, when the fracture surface of the sintered body was observed by SEM, as shown in FIG. 3, the sintered body had a dense structure with no clear grain boundaries. The sintered body was etched with molten NaOH and the particle size was examined. As a result, the sintered body was a homogeneous sintered body composed of particles of 2 to 5 μm. Further, the Vickers hardness of the sintered body was 50 GPa or more when measured under a load of 2 kg.
これらより、得られた焼結体は、透光性で、非常に高
純度且つ高硬度であり、粒子径は２〜５μｍの均質なcB
N焼結体であることが確認された。From these, the obtained sintered body is translucent, has very high purity and high hardness, and has a uniform cB particle size of 2 to 5 μm.
It was confirmed that it was an N sintered body.
比較例１ 市販の高純度hBN焼結体の酸素含有量を測定したとこ
ろ、0.3wt％であった。この焼結体を実施例１と同様な
試料構成にし、7.7GPa、2150℃で30分間の条件で焼結し
た。得られた試料は、cBNに完全に変換していたが、黒
色不透明であった。Comparative Example 1 The oxygen content of a commercially available high-purity hBN sintered body was measured and found to be 0.3% by weight. This sintered body was made into the same sample configuration as in Example 1, and was sintered at 7.7 GPa and 2150 ° C. for 30 minutes. The resulting sample was completely converted to cBN, but was black and opaque.
比較例２ 酸素含有量0.06wt％のhBN焼結体をTaカプセルに密閉
しないでTa箔で包んだ試料構成とした以外は、実施例１
と全く同じ条件で焼結した。得られた焼結体は、cBNに
完全に変換していたが、焼結体の周囲が同心円状に白
く、中心部分は黒色であった。中心部分は僅かに光を通
すが、他の部分は不透明であった。焼結体の白い部分
は、10μｍ以上に粒成長していた。これは、Taカプセル
の密閉が十分でないために、試料に部分的にNaClが侵入
したため、透光性焼結体が得られなかったものと考えら
れる。Comparative Example 2 Example 1 except that the hBN sintered body having an oxygen content of 0.06 wt% was not sealed in a Ta capsule but was wrapped in a Ta foil and a sample configuration was adopted.
Sintering was performed under exactly the same conditions. Although the obtained sintered body was completely converted to cBN, the periphery of the sintered body was concentrically white and the center was black. The central part was slightly opaque, while the other parts were opaque. The white part of the sintered body had grown to 10 μm or more. It is considered that the translucent sintered body was not obtained because NaCl partially entered the sample because the Ta capsule was not sufficiently sealed.
実施例２ 酸素含有量0.06wt％のhBN粉末を7GPa、2100℃、30分
間の条件で、実施例１と全く同じ試料構成を用いて焼結
した。得られた試料は、透光性高純度cBN焼結体である
ことが確認された。この試料の耐熱性を調べるため、５
×10-5Torrの真空中、1300℃の条件で２時間処理したと
ころ、全くhBNの析出は認められなかった。なお、1400
℃、１時間の条件で処理したところ、一部分がhBNに変
換していることがＸ線回折により認められた。Example 2 hBN powder having an oxygen content of 0.06 wt% was sintered under the conditions of 7 GPa, 2100 ° C., and 30 minutes, using exactly the same sample configuration as in Example 1. It was confirmed that the obtained sample was a translucent high-purity cBN sintered body. To check the heat resistance of this sample,
When treated at 1300 ° C. for 2 hours in a vacuum of × 10 −5 Torr, no deposition of hBN was observed. In addition, 1400
When treated at 1 ° C. for 1 hour, it was confirmed by X-ray diffraction that a part was converted to hBN.
比較例３ 酸素含有量0.06wt％のhBN焼結体に触媒（焼結助剤）M
g3BN3を拡散含浸させ、0.8モル％のMg3BN3を含む試料を
作製した。この試料を5.8GPa、1500℃の条件で焼結し
た。得られた試料は、透光性cBN焼結体で、Ｘ線回折で
はMg3BN3は全く認められなかった。しかし、EPMAでは微
量のMgが検出された。この焼結体の耐熱性を調べるた
め、実施例２と同じ真空度のもとで、1100℃、１時間の
条件で処理した。処理後、試料のＸ線回折した結果、一
部分がhBNに変換していた。このように低い温度からhBN
の析出が認められるのは、微量の触媒（焼結助剤）が焼
結体中に残留しているためと考えられる。Comparative Example 3 Catalyst (Sintering Aid) M for hBN Sintered Body with Oxygen Content of 0.06wt%
g 3 BN 3 was diffused and impregnated to prepare a sample containing 0.8 mol% of Mg 3 BN 3 . This sample was sintered under the conditions of 5.8 GPa and 1500 ° C. The obtained sample was a translucent cBN sintered body, and Mg 3 BN 3 was not observed at all by X-ray diffraction. However, trace amounts of Mg were detected in EPMA. In order to examine the heat resistance of this sintered body, the sintered body was treated at 1100 ° C. for 1 hour under the same vacuum as in Example 2. After the treatment, as a result of X-ray diffraction of the sample, a part was converted to hBN. HBN from such low temperature
It is considered that the precipitation of is observed because a trace amount of the catalyst (sintering aid) remains in the sintered body.
（発明の効果） 以上詳述したように、本発明によれば、焼結助剤を全
く使用しないで透光性、高純度のcBN焼結体が得られ、
この焼結体は高硬度で耐熱性に優れているため、特殊な
用途の窓材料、ボンデングツール、難削材料の切削工具
等への応用に適している。(Effects of the Invention) As described in detail above, according to the present invention, a translucent, high-purity cBN sintered body can be obtained without using any sintering aid,
Since this sintered body has high hardness and excellent heat resistance, it is suitable for application to window materials for special applications, bonding tools, cutting tools of difficult-to-cut materials, and the like.
なお、本発明での焼結体の合成条件が従来の焼結体合
成条件に比べて厳しいという難点があるが、得られる焼
結体の特性が非常に優れており、且つ厳しい高温高圧条
件に耐え得る高圧装置も開発されていることを勘案する
と、単に圧力、温度が高いから工業的な製品化が難しい
と断定することは早計であり、厳しい高温高圧条件での
合成であっても、余りある性能を有する焼結体であるの
で、実用化もさして困難ではない。Although the synthesis conditions of the sintered body in the present invention are disadvantageous in that they are stricter than the conventional conditions for synthesizing a sintered body, the characteristics of the obtained sintered body are very excellent, and the conditions under severe high temperature and high pressure conditions Considering that high-pressure equipment that can withstand is also being developed, it is too early to conclude that it is difficult to commercialize the product simply because the pressure and temperature are high. Since it is a sintered body having a certain performance, it is not difficult to put it to practical use.
第１図はベルト型高圧装置の圧力媒体を含めた試料部の
断面図であり、 第２図は試料部の試料構成を説明する縦断面図であり、 第３図は実施例で得られた透光性、高純度cBN焼結体の
破面の粒子構造に係るSEM像（二次電子像）を示す写真
である。 １……ゴム製Ｏリング、２……成形ガスケット、３……
パイロフィライトガスケット、４……ステンレス板、５
……通電リング、６……NaCl−10wt％ZrO2（焼結媒
体）、７……ZrO2焼結体、８……Mo板、９……試料部、
10……黒鉛ヒーター、111……外側Taカプセル、112……
内側Taカプセル、12……hBN試料、13……NaCl−20wt％Z
rO2（焼結媒体）。FIG. 1 is a cross-sectional view of a sample section including a pressure medium of a belt-type high-pressure device, FIG. 2 is a vertical cross-sectional view illustrating a sample configuration of the sample section, and FIG. 3 is obtained in Example. 3 is a photograph showing a SEM image (secondary electron image) of a particle structure of a fracture surface of a translucent, high-purity cBN sintered body. 1 ... rubber O-ring, 2 ... molded gasket, 3 ...
Pyrophilite gasket, 4 ... stainless steel plate, 5
...... energizing ring, 6 ...... NaCl-10wt% ZrO 2 ( sintering medium), 7 ...... ZrO 2 sintered body, 8 ...... Mo plate, 9 ...... sample portion,
10 …… Graphite heater, 11 1 …… Outer Ta capsule, 11 2 ……
Inner Ta capsule, 12 ... hBN sample, 13 ... NaCl-20wt% Z
rO 2 (sintering medium).
Claims (1)
う素を、立方晶窒化ほう素の熱力学的安定条件下の7GPa
以上の圧力及び2100℃以上の温度で、焼結助剤を用い
ず、不純物を前記六方晶窒化ほう素に混入させることな
く高温高圧焼結することを特徴とする透光性高純度立方
晶窒化ほう素焼結体の製造法。1. A hexagonal boron nitride having an oxygen content of not more than 0.06 wt% is converted to 7 GPa under thermodynamically stable conditions of cubic boron nitride.
Translucent high-purity cubic nitride characterized by high-temperature and high-pressure sintering at the above pressure and at a temperature of 2100 ° C. or higher without using a sintering aid and without mixing impurities into the hexagonal boron nitride. A method for producing a boron sintered body.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1300587A JP2590413B2 (en) | 1989-11-17 | 1989-11-17 | Method for producing translucent high-purity cubic boron nitride sintered body |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1300587A JP2590413B2 (en) | 1989-11-17 | 1989-11-17 | Method for producing translucent high-purity cubic boron nitride sintered body |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH03159964A JPH03159964A (en) | 1991-07-09 |
| JP2590413B2 true JP2590413B2 (en) | 1997-03-12 |
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ID=17886639
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1300587A Expired - Lifetime JP2590413B2 (en) | 1989-11-17 | 1989-11-17 | Method for producing translucent high-purity cubic boron nitride sintered body |
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| Country | Link |
|---|---|
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Cited By (1)
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|---|---|---|---|---|
| WO2018005406A1 (en) * | 2016-06-29 | 2018-01-04 | Smith International, Inc. | Binderless cbn sintering with cubic press |
Families Citing this family (16)
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|---|---|---|---|---|
| JPH10158065A (en) * | 1996-11-28 | 1998-06-16 | Sumitomo Electric Ind Ltd | Cubic boron nitride sintered compact and its production |
| JPH11322310A (en) * | 1998-05-11 | 1999-11-24 | Sumitomo Electric Ind Ltd | Cubic boron nitride polycrystalline abrasive grain and its production |
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| WO2001066492A1 (en) | 2000-03-08 | 2001-09-13 | Sumitomo Electric Industries, Ltd. | Coated sinter of cubic-system boron nitride |
| JP3882078B2 (en) * | 2002-12-17 | 2007-02-14 | 独立行政法人物質・材料研究機構 | Manufacturing method of high purity ultrafine cubic boron nitride sintered body |
| JP3877677B2 (en) * | 2002-12-18 | 2007-02-07 | 独立行政法人科学技術振興機構 | Heat resistant diamond composite sintered body and its manufacturing method |
| JP2008019164A (en) * | 2007-08-08 | 2008-01-31 | National Institute For Materials Science | Superfine particulate cubic boron nitride sintered compact |
| EP2354110B1 (en) | 2010-02-09 | 2014-06-25 | Mitsubishi Materials Corporation | Method for producing sintered cubic boron nitride compact |
| EP2942341B1 (en) | 2011-08-30 | 2020-11-18 | Sumitomo Electric Industries, Ltd. | Cubic boron nitride complex polycrystalline substance, method for manufacturing same, cutting tool, wire-drawing die, and grinding tool |
| CN103569976B (en) * | 2012-08-03 | 2016-09-14 | 燕山大学 | Ultrahigh hardness nano twin crystal boron nitride block materials and synthetic method thereof |
| JP6291995B2 (en) | 2014-04-18 | 2018-03-14 | 住友電気工業株式会社 | Cubic boron nitride polycrystal, cutting tool, wear-resistant tool, grinding tool, and method for producing cubic boron nitride polycrystal |
| JP2016060680A (en) * | 2014-09-19 | 2016-04-25 | 信越化学工業株式会社 | Boron nitride agglomerate and thermally conductive composition |
| JP6447197B2 (en) | 2015-02-04 | 2019-01-09 | 住友電気工業株式会社 | Cubic boron nitride polycrystal, cutting tool, wear-resistant tool, grinding tool, and method for producing cubic boron nitride polycrystal |
| JP6447205B2 (en) | 2015-02-09 | 2019-01-09 | 住友電気工業株式会社 | Cubic boron nitride polycrystal, cutting tool, wear-resistant tool, grinding tool, and method for producing cubic boron nitride polycrystal |
| WO2018066261A1 (en) | 2016-10-06 | 2018-04-12 | 住友電気工業株式会社 | Method for producing boron nitride polycrystal, boron nitride polycrystal, cutting tool, wear-resistant tool, and grinding tool |
| CN110467469B (en) * | 2019-08-28 | 2023-04-25 | 郑州中南杰特超硬材料有限公司 | Preparation method of precursor for synthesizing polycrystalline cubic boron nitride |
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- 1989-11-17 JP JP1300587A patent/JP2590413B2/en not_active Expired - Lifetime
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2018005406A1 (en) * | 2016-06-29 | 2018-01-04 | Smith International, Inc. | Binderless cbn sintering with cubic press |
| US11066334B2 (en) | 2016-06-29 | 2021-07-20 | Schlumberger Technology Corporation | Binderless cBN sintering with cubic press |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH03159964A (en) | 1991-07-09 |
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