JP2733269B2 - Method for producing single-crystal cubic boron nitride particles - Google Patents
Method for producing single-crystal cubic boron nitride particlesInfo
- Publication number
- JP2733269B2 JP2733269B2 JP31857588A JP31857588A JP2733269B2 JP 2733269 B2 JP2733269 B2 JP 2733269B2 JP 31857588 A JP31857588 A JP 31857588A JP 31857588 A JP31857588 A JP 31857588A JP 2733269 B2 JP2733269 B2 JP 2733269B2
- Authority
- JP
- Japan
- Prior art keywords
- boron nitride
- cubic boron
- temperature
- cbn
- particles
- 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.)
- Expired - Lifetime
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J3/00—Processes of utilising sub-atmospheric or super-atmospheric pressure to effect chemical or physical change of matter; Apparatus therefor
- B01J3/06—Processes using ultra-high pressure, e.g. for the formation of diamonds; Apparatus therefor, e.g. moulds or dies
- B01J3/062—Processes using ultra-high pressure, e.g. for the formation of diamonds; Apparatus therefor, e.g. moulds or dies characterised by the composition of the materials to be processed
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2203/00—Processes utilising sub- or super atmospheric pressure
- B01J2203/06—High pressure synthesis
- B01J2203/0605—Composition of the material to be processed
- B01J2203/0645—Boronitrides
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2203/00—Processes utilising sub- or super atmospheric pressure
- B01J2203/06—High pressure synthesis
- B01J2203/065—Composition of the material produced
- B01J2203/066—Boronitrides
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2203/00—Processes utilising sub- or super atmospheric pressure
- B01J2203/06—High pressure synthesis
- B01J2203/0675—Structural or physico-chemical features of the materials processed
- B01J2203/068—Crystal growth
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Crystals, And After-Treatments Of Crystals (AREA)
- Ceramic Products (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、鉄系金属材料等の研削加工に用いられる単
結晶型の立方晶窒化ほう素粒子の製造方法に関する。Description: TECHNICAL FIELD The present invention relates to a method for producing single-crystal cubic boron nitride particles used for grinding iron-based metal materials and the like.
〔従来の技術〕 立方晶窒化ほう素（cBN）は、ダイヤモンドに次ぐ硬
さ、熱伝導率を有し、しかもダイヤモンドよりも優れた
化学的安定性特に耐酸化性、鉄系金属に対する安定性を
有することから、鋼、ステンレス、Ni基合金などの鉄系
金属の加工用工具材料として広く用いられている。研削
加工には通常は触媒成長法で合成された単結晶型cBN粒
子が用いられる。[Conventional technology] Cubic boron nitride (cBN) has the second highest hardness and thermal conductivity next to diamond, and has better chemical stability than diamond, especially oxidation resistance, and stability against iron-based metals. Because of this, it is widely used as a tool material for processing ferrous metals such as steel, stainless steel, and Ni-based alloys. Normally, single crystal type cBN particles synthesized by a catalyst growth method are used for grinding.
単結晶型cBN粒子は、従来、原料の六方晶窒化ほう素
（hBN）粉末とcBN転換触媒粉末の混合物を高温高圧処理
することにより製造されている。そして、その際のcBN
転換触媒としては、空気中での安定性に優れかつ取扱い
が容易であること、さらには少量でも高い転換効率が得
られることから、アルカリ土類金属のほう窒化物が用い
られている（特開昭62−108772号公報、同63−260865号
公報）。Conventionally, single-crystal cBN particles have been produced by subjecting a mixture of raw material hexagonal boron nitride (hBN) powder and cBN conversion catalyst powder to high-temperature and high-pressure treatment. And cBN at that time
As a conversion catalyst, an alkaline earth metal boronitride is used because of its excellent stability in air and easy handling, and high conversion efficiency can be obtained even in a small amount. JP-A-62-108772 and JP-A-63-260865).
しかし、この方法では原料が粉末であるために、高温
高圧装置の試料部への原料充填効率に限界があり生産性
を低下させる大きな原因となつていた。粉末原料を空隙
なく試料部に充填することは困難であり、通常数十％以
上の空隙が存在する。超高圧力を用いるcBNの合成はバ
ツチ式であり、限られた容積の試料部空間にどれだけ効
率良く原料が充填できるかにより生産効率がほぼ決定さ
れる。従つて、粉末原料を用いる従来の方法では必然的
に存在している粉末粒子間の空隙は、そのまま試料部の
無駄な空間となつて、原料の充填効率を低下させていた
のである。However, in this method, since the raw material is a powder, the efficiency of charging the raw material into the sample portion of the high-temperature and high-pressure apparatus is limited, which is a major cause of lowering the productivity. It is difficult to fill the sample portion with the powdery raw material without voids, and usually there are several tens% or more voids. The synthesis of cBN using ultra-high pressure is a batch type, and the production efficiency is almost determined by how efficiently the raw material can be filled in a limited space of the sample section. Therefore, in the conventional method using the powder raw material, the voids between the powder particles which are necessarily present become a useless space in the sample portion as it is, and lower the raw material filling efficiency.
本発明は、cBN粒子の従来の合成法が有していた以上
の問題点を解決し、従来と同等性能の単結晶型粒子を、
従来よりも高い生産性で、従つてより安価に製造するこ
とを目的とするものである。The present invention solves the above problems that the conventional synthesis method of cBN particles had, and single crystal type particles having the same performance as the conventional one,
It is intended to produce with higher productivity than before, and therefore at lower cost.
即ち、本発明は、熱分解窒化ほう素（Ｐ−BN）成型体
にアルカリ土類金属のほう窒化物を拡散含有させ、これ
を立方晶窒化ほう素の熱力学的安定条件下で高温高圧処
理して立方晶窒化ほう素に転換する方法において、前記
ほう窒化物としてストロンチウム及び／又はバリウムの
ほう窒化物を用い、かつ、前記高温高圧処理を温度1650
℃以上、圧力4.9GPa以上として単結晶型立方晶窒化ほう
素と再結晶六方晶窒化ほう素を含む生成物を得、分離す
ることを特徴とする単結晶型立方晶窒化ほう素粒子の製
造方法である。That is, the present invention is to provide a pyrolytic boron nitride (P-BN) molded body containing a boron nitride of an alkaline earth metal in a diffused state, and subjecting it to high temperature and high pressure treatment under thermodynamically stable conditions of cubic boron nitride. Strontium and / or barium boronitride as the boronitride, and performing the high-temperature high-pressure treatment at a temperature of 1650.
A method comprising producing a product containing single-crystal cubic boron nitride and recrystallized hexagonal boron nitride at a temperature of not less than ℃ and a pressure of not less than 4.9 GPa, and separating the product. It is.
以下、詳しく本発明について説明する。 Hereinafter, the present invention will be described in detail.
本発明は、cBN焼結体の製造条件を種々検討する過程
で得た知見、即ち、Sr3BN3及び／又はBa3BN3をＰ−BNに
拡散含浸した原料を高温高圧処理する場合に、温度1650
℃以上、圧力4.9GPa以上で行うと、cBN単一焼結体では
なく、処理中に生成するBNと触媒の共融液から再析出し
たと思われるhBN粉と単結晶型cBN粒子の複合体が生成す
ることを利用するものである。このようにして生成する
複合体は、単結晶型cBN粒子間に微細で柔いhBN粉が存在
する構造をしており、たとえば、ボールミルなどの機械
的手段により簡単に解砕できる他、300℃程度でアルカ
リ融解するとhBNは溶出し、cBNの単結晶粒子のみが分離
できる。このようにして得られるcBN粒子は現在市販さ
れているcBN粒子と同等の研削性能を示す。本発明の利
点は、原料としてcBN転換触媒のSr3BN3及び／又はBa3BN
3を含浸したＰ−BN成型体を用いるので、高温高圧装置
の試料部に原料を充填する時に、試料部空間の無駄がな
く、空間の全てに原料を充填でき、生産効率が従来より
も著しく改善される点にある。即ち、従来の方法では、
試料部への原料の充填効率は60〜70％程度しかなかつた
が、本発明ではこれがほぼ100％となり、空間効率とし
て５割の改善となる。The present invention is based on the findings obtained in the process of variously examining the manufacturing conditions for cBN sintered bodies, that is, when performing high-temperature and high-pressure treatment on a material obtained by diffusing and impregnating P-BN with Sr 3 BN 3 and / or Ba 3 BN 3. , Temperature 1650
When performed at ℃ or more and pressure of 4.9GPa or more, it is not a single sintered body of cBN, but a composite of hBN powder and single-crystal type cBN particles which seems to be reprecipitated from the eutectic liquid of BN and catalyst generated during processing. Is generated. The composite thus formed has a structure in which fine and soft hBN powder exists between the single-crystal type cBN particles, and can be easily crushed by mechanical means such as a ball mill, and at 300 ° C. The hBN is eluted when the alkali is melted to the extent that only single crystal particles of cBN can be separated. The cBN particles obtained in this manner exhibit the same grinding performance as currently available cBN particles. An advantage of the present invention is that the cBN conversion catalyst Sr 3 BN 3 and / or Ba 3 BN
Since the P-BN molded body impregnated with 3 is used, when filling the sample part of the high-temperature and high-pressure equipment with the raw material, there is no waste of the sample part space, and the whole space can be filled with the raw material, and the production efficiency is significantly higher than before. The point is that it can be improved. That is, in the conventional method,
Although the efficiency of filling the raw material into the sample portion is only about 60 to 70%, in the present invention, this is almost 100%, and the space efficiency is improved by 50%.
本発明を実施する場合、高温高圧処理装置として、た
とえば特公昭53−34189号公報、同53−34190号公報に開
示されているフラツトベルト型装置を用い、その処理条
件を温度1650℃以上、圧力4.9GPa以上とすることが必要
である。これよりも低い温度ではhBNの再結晶が十分に
起こらず、cBN粒子間の部分的焼結がおこり、目的とす
る高品質の単結晶粒子が得られない。また圧力が4.9GPa
未満では、hBNの熱力学的安定域となるため、そもそもc
BNへの転換が起こりえない。高温高圧の保持時間として
は、５分間以上が好ましく、これ以下では十分な量のcB
Nが生成しない。cBN転換触媒の使用量としてはＰ−BN成
型体に対し0.1〜５モル％が適切である。In carrying out the present invention, as a high-temperature and high-pressure processing apparatus, for example, a flat belt type apparatus disclosed in Japanese Patent Publication Nos. 53-34189 and 53-34190 is used. It must be GPa or higher. At a temperature lower than this, hBN recrystallization does not sufficiently occur, and partial sintering between cBN particles occurs, so that the desired high-quality single crystal particles cannot be obtained. The pressure is 4.9GPa
If the value is less than c, it will be in the thermodynamic stability region of hBN.
Conversion to BN cannot occur. The holding time at high temperature and high pressure is preferably 5 minutes or more, and below this, a sufficient amount of cB
N does not generate. The amount of the cBN conversion catalyst used is suitably from 0.1 to 5 mol% based on the P-BN molded body.
次に実施例をあげて本発明を更に具体的に説明する。 Next, the present invention will be described more specifically with reference to examples.
Sr3N2の粉末中にＰ−BN円板（７mmφ×1mmt）を埋
め、N2気流中、670℃で15時間保持後冷却して、0.6モル
％のSr3BN3を拡散含浸したＰ−BN原料を得た。同様にし
てBa3N2を用い、0.6モル％のBa3BN3を拡散含浸したＰ−
BN原料を合成した。但しこの場合の拡散含浸は840℃で1
5時間かけて行つた。これらの原料を内径25mmのシリン
ダを有するフラツトベルト型装置を用いて種々の条件で
処理し、生成物をＸ線回折により同定した。その結果を
表１に示す。A P-BN disc (7 mmφ × 1 mmt ) is buried in Sr 3 N 2 powder, kept at 670 ° C. for 15 hours in an N 2 gas stream, cooled, and diffused and impregnated with 0.6 mol% of Sr 3 BN 3 The obtained P-BN raw material was obtained. In the same manner, P-diffusion impregnated with 0.6 mol% of Ba 3 BN 3 using Ba 3 N 2
BN raw material was synthesized. However, diffusion impregnation in this case is 1 at 840 ° C.
I went for 5 hours. These raw materials were treated under various conditions using a flat belt type apparatus having a cylinder having an inner diameter of 25 mm, and the products were identified by X-ray diffraction. Table 1 shows the results.
なお、比較例には従来法として、市販hBN粉末にBa3BN
3及びSr3BN3粉末を５モル％混合し、cBNに転換した場合
（従来例１、２）もあわせて示す。In the comparative example, Ba 3 BN was added to a commercially available hBN powder as a conventional method.
3 and Sr 3 BN 3 powder were mixed at 5 mol% and converted to cBN (conventional examples 1 and 2).
本発明の生成物はいずれもその90％以上が単結晶型cB
Nであり、しかもその粒子間にhBN微粉末が存在するの
で、次いで生成物をボールミルで30分間処理して解砕
し、個々の単結晶cBN粒子にわけた後、更にこれを300℃
のKOHでアルカリ融解処理した。その結果、hBNが除去さ
れて、cBN粒子のみが分離できたことをＸ線回折法によ
り確認した。90% or more of all products of the present invention are single crystal type cB
N, and hBN fine powder is present between the particles.Then, the product is treated with a ball mill for 30 minutes to be crushed, separated into individual single-crystal cBN particles, and further heated to 300 ° C.
Was alkali-melted with KOH. As a result, it was confirmed by X-ray diffraction that hBN was removed and only cBN particles could be separated.
１バツチで最終的に得られるcBNの容積は、高温高圧
装置試料部容積に対し、本発明の場合で58〜60％である
のに対し、従来例ではわずかにその６割程度しかなく、
本発明が高い生産性を有することが明らかとなつた。In the case of the present invention, the volume of cBN finally obtained by one batch is 58 to 60% of the volume of the sample part of the high-temperature and high-pressure apparatus, whereas in the conventional example, it is only about 60%.
It has been found that the invention has a high productivity.
〔発明の効果〕 本発明によれば、cBN粒子合成時の原料の充填効率は
従来の方法に対して50％以上改善されるので製造コスト
の低減が可能となる。 [Effects of the Invention] According to the present invention, the charging efficiency of raw materials at the time of synthesizing cBN particles is improved by 50% or more as compared with the conventional method, so that the production cost can be reduced.
Claims (1)
属のほう窒化物を拡散含有させ、これを立方晶窒化ほう
素の熱力学的安定条件下で高温高圧処理して立方晶窒化
ほう素に転換する方法において、前記ほう窒化物として
ストロンチウム及び／又はバリウムのほう窒化物を用
い、かつ、前記高温高圧処理を温度1650℃以上、圧力4.
9GPa以上として単結晶型立方晶窒化ほう素と再結晶六方
晶窒化ほう素含む生成物を得、分離することを特徴とす
る単結晶型立方晶窒化ほう素粒子の製造方法。A cubic boron nitride is produced by diffusing a boron nitride of an alkaline earth metal into a pyrolytic boron nitride molding and subjecting it to high-temperature and high-pressure treatment under thermodynamically stable conditions of cubic boron nitride. In the method of converting to boron, strontium and / or barium boronitride is used as the boronitride, and the high-temperature and high-pressure treatment is performed at a temperature of 1650 ° C. or more and a pressure of 4.
A method for producing single-crystal cubic boron nitride particles, comprising obtaining and separating a product containing single-crystal cubic boron nitride and recrystallized hexagonal boron nitride at 9 GPa or more.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP31857588A JP2733269B2 (en) | 1988-12-19 | 1988-12-19 | Method for producing single-crystal cubic boron nitride particles |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP31857588A JP2733269B2 (en) | 1988-12-19 | 1988-12-19 | Method for producing single-crystal cubic boron nitride particles |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH02164434A JPH02164434A (en) | 1990-06-25 |
| JP2733269B2 true JP2733269B2 (en) | 1998-03-30 |
Family
ID=18100664
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP31857588A Expired - Lifetime JP2733269B2 (en) | 1988-12-19 | 1988-12-19 | Method for producing single-crystal cubic boron nitride particles |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2733269B2 (en) |
-
1988
- 1988-12-19 JP JP31857588A patent/JP2733269B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH02164434A (en) | 1990-06-25 |
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