JPH0920951A - Highly heat-resistant and highly tough diamond sintered compact and its production - Google Patents

Abstract

PURPOSE: To impart excellent heat resistance and high toughness to a diamond sintered compact and to improve its heavy intermittent cutting characteristics to nonferrous materials, nonmetals or the like by specifying its compsn. and forming it into the one composed of diamond and Co bonding phases and in which precipitation hardening occurs by Co base intermetallic compounds. CONSTITUTION: This sintered compact contains, by weight, 50 to 98% diamond, and the balance bonding metallic phases, and this bonding metallic phases contain 0.5 to 6% of one or >= two kinds selected from Si, Ti, Zr and Mo, and the balance Co. Moreover, the bonding metallic phases contain precipitated Co base intermetallic compounds. Furthermore, at the time of producing the sintered compact, these diamond powder and metallic powder are mixed, and in the powdery state as it is, or after compacting, sintering is executed under heating to >=1350 deg.C under >=5GPa by using a superhigh temp. high pressure device. Moreover, the average grain size of the diamond powder and the metallic powder at this time is preferably regulated to about 5μm and 1μm respectively.

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【発明の属する技術分野】本発明は、ダイヤモンドと、
Ｃｏ系金属間化合物相の析出硬化により強化されたＣｏ
を含む結合金属相とからなる切削工具等に適した高耐
熱、高靱性ダイヤモンド焼結体およびその製造法に関す
るものである。TECHNICAL FIELD The present invention relates to a diamond,
Co strengthened by precipitation hardening of Co-based intermetallic compound phase
The present invention relates to a highly heat-resistant and high-toughness diamond sintered body suitable for a cutting tool and the like, which is composed of a bonded metal phase containing a and a manufacturing method thereof.

【０００２】[0002]

【従来の技術】ダイヤモンドは、最も硬くまた熱伝導率
も最高の物質であり、現在研削用砥粒として使用されて
いるほか、焼結体として切削用途等に用いられている。
市販されているダイヤモンド焼結体工具には、金属Ｃｏ
を結合材としたものと、ＷＣ−Ｃｏ系サーメットを結合
材としたものがある。金属Ｃｏを結合材としたものは、
結合金属相の高温での軟化による耐摩耗性の低下や被削
材金属の溶着等の欠点があり、刃先が高温度となるよう
な切削には不適であった。又ＷＣ−Ｃｏ系サーメットを
結合材としたものは、耐熱衝撃性、耐酸化性の点で劣り
断続切削用途には適しない等の課題があった。2. Description of the Related Art Diamond is the hardest material and has the highest thermal conductivity, and is currently used as an abrasive grain for grinding as well as a sintered body for cutting purposes.
Commercially available diamond sintered body tools include metallic Co
There is a binder as a binder and a binder as a WC-Co cermet. The one using metal Co as a binder is
It has disadvantages such as deterioration of wear resistance due to softening of the bonded metal phase at high temperature and welding of work material metal, which is not suitable for cutting where the cutting edge has a high temperature. Further, the WC-Co cermet as a binder has a problem in that it is inferior in thermal shock resistance and oxidation resistance and is not suitable for intermittent cutting applications.

【０００３】そこでそれぞれ出願人の出願になる、特開
昭62─260036号公報ではダイヤモンドを重量％で５０〜
９５％含有し、残部が、Ｍｏ又はＮｉを含みかつＴｉ，
Ｚｒ，Ｔａ，Ａｌの中から選ばれた１種もしくは２種以
上の元素を重量％で０．５〜６％含有する結合金属相で
あることを特徴とする高硬度ダイヤモンド焼結体が開示
され、特開平５─320812号公報ではダイヤモンドが７０
〜９５体積％を占め、残部に、Ｃｏ及び／又はＦｅを１
成分とし、これにＳｉ，Ｂ，Ｐ，Ｃの中から選ばれた少
なくとも２種を含むアモルファス化可能である組成の合
金が均一に分散していることを特徴とするダイヤモンド
焼結体が開示されている（この明細書には１種を含むと
記載されているが１種を含むものは実施例にもなく２種
を含むの誤記である）。しかしながらこれら２つの開示
のものは従来技術よりは改良されたものではあったがな
お高耐熱、高靱性に課題があった。Therefore, in Japanese Patent Application Laid-Open No. 62-260036, each of which is filed by the applicant, the diamond content is 50 to 50% by weight.
95% contained, the balance contains Mo or Ni and Ti,
Disclosed is a high hardness diamond sintered body characterized by being a bonded metal phase containing 0.5 to 6% by weight of one or more elements selected from Zr, Ta and Al. In JP-A-5-320812, diamond is 70
Occupy ˜95% by volume, and balance Co and / or Fe 1
Disclosed is a diamond sintered body characterized in that an alloy having a composition capable of being amorphized and containing at least two kinds selected from Si, B, P and C as components is uniformly dispersed. (In this specification, it is described that one kind is included, but what includes one kind is not included in the examples and is erroneous to include two kinds.). However, although these two disclosures are improvements over the prior art, they still have problems in high heat resistance and high toughness.

【０００４】[0004]

【発明が解決しようとする課題】一般に、非鉄材料、非
金属等の重断続切削においては、耐熱衝撃性、高温強度
が特に重要である。従来のダイヤモンド焼結体には、前
記したとおり、刃先が高温度となるような切削には不適
であり、非鉄材料、非金属等の重断続切削には不向きで
ある。そこで、本発明の課題は、非鉄材料、非金属等の
重断続切削において、耐熱性および高温特性にすぐれた
高耐熱、高靱性ダイヤモンド焼結体およびその製造法を
提供することにある。Generally, in heavy interrupted cutting of non-ferrous materials, non-metals, etc., thermal shock resistance and high temperature strength are particularly important. As described above, the conventional diamond sintered body is not suitable for cutting in which the cutting edge has a high temperature, and is not suitable for heavy interrupted cutting of nonferrous materials, nonmetals, and the like. Therefore, an object of the present invention is to provide a highly heat-resistant and high-toughness diamond sintered body having excellent heat resistance and high-temperature characteristics in heavy interrupted cutting of non-ferrous materials, non-metals and the like, and a method for producing the same.

【０００５】[0005]

【課題を解決するための手段】このため本発明の第１発
明によると、ダイヤモンドを重量％で５０〜９８％含有
し、残部が結合金属相からなり、前記結合金属相はＳ
ｉ，Ｔｉ，Ｚｒ，Ｍｏの中から選ばれた１種又は２種以
上の元素を重量％で０．５〜６％を含みかつ残余をＣｏ
からなることを特徴とする高耐熱、高靱性ダイヤモンド
焼結体を提供することによって上述した従来技術の課題
を解決した。さらに本発明の第２発明によると、ダイヤ
モンド粉末を重量で５０〜９８％、残部が金属粉末で、
前記金属粉末は、Ｓｉ，Ｔｉ，Ｚｒ，Ｍｏの中から選ば
れた１種又は２種以上の金属粉末を重量％で０．５〜６
％含みかつ残余をＣｏ金属粉末とし、これら粉末を混合
し、そして粉末状で又は圧粉成形後、超高圧高温装置を
用いて５ＧＰａ以上の高圧下で１３５０℃以上の温度に
加熱して焼結することを特徴とする高耐熱、高靱性ダイ
ヤモンド焼結体の製造法を提供することによって上述し
た従来技術の課題を解決した。For this reason, according to the first aspect of the present invention, diamond is contained in an amount of 50 to 98% by weight, and the balance is composed of a bonding metal phase, and the bonding metal phase is S.
i, Ti, Zr, Mo, one or more elements selected from the range of 0.5 to 6% by weight and the balance Co
The problems of the prior art described above have been solved by providing a highly heat-resistant, high-toughness diamond sintered body characterized by comprising Furthermore, according to the second aspect of the present invention, the diamond powder is 50 to 98% by weight, and the balance is metal powder,
The metal powder is 0.5 to 6% by weight of one or more metal powders selected from Si, Ti, Zr and Mo.
%, And the balance is Co metal powder, and these powders are mixed and sintered in powder form or after compacting by heating to a temperature of 1350 ° C. or higher under a high pressure of 5 GPa or more using an ultrahigh pressure and high temperature apparatus. By providing a method for producing a highly heat-resistant and high-toughness diamond sintered body, which is characterized by the above, the above-mentioned problems of the prior art are solved.

【０００６】詳説すると、ダイヤモンドに対する触媒作
用をなすものとしてＣｏを加えると同時に、Ｃｏ系金属
間化合物を形成する元素である、Ｓｉ，Ｔｉ，Ｚｒ，Ｍ
ｏの中より、１種または２種以上を０．５〜６％添加
し、Ｃｏ基地の分散強化により高温強度の向上を図るこ
とによって従来技術の課題を克服したものである。好ま
しくは結合相中にＣｏ系金属間化合物を析出させ、Ｃｏ
基地をより分散強化させてより高温強度の向上を図るこ
とができる。More specifically, Si, Ti, Zr, and M, which are elements that form Co-based intermetallic compounds at the same time when Co is added as a catalyst for diamond, are formed.
In order to improve the high temperature strength by adding 0.5 to 6% of one or two or more of the above mentioned o, and overcoming the problems of the prior art. Preferably, a Co-based intermetallic compound is precipitated in the binder phase, and Co
The base can be further dispersed and strengthened to improve the high temperature strength.

【０００７】結合金属であるＣｏとダイヤモンドとの重
量比は、適用条件によって種々変えることができ、ダイ
ヤモンドは、重量比で５０〜９８％まで選定できる。切
削工具としての耐摩耗性を有するためには、ダイヤモン
ドは５０％以上必要であり、さらに焼結体工具としての
靱性を維持するためには、ダイヤモンドは９８％以下で
なければならない。また、結合相を強化するために、析
出硬化型のＣｏ系金属間化合物を形成する元素であるＳ
ｉ，Ｔｉ，Ｚｒ，Ｍｏの中から１種または２種以上を重
量で０．５〜６％添加する。この場合、０．５％以下で
は効果がなく、６％以上では靱性が低下する。本発明焼
結体の製造方法としては、前記組成のダイヤモンドとＣ
ｏと添加元素粉末を所定割合に配合して、ボールミルな
どにより混合し、これを粉末状で、もしくは、圧粉成形
後、混合過程での吸着水分等を除くために真空中で４０
０〜７００℃で乾燥し、ベルト型又は、ガードル型の超
高圧装置を用いて、超高圧高温の条件で焼結する。焼結
条件は、基本的にはダイヤモンドの安定存在域で行う必
要があるが、ダイヤモンドとＣｏとの配合割合によって
変わり、圧力は５ＧＰａ（５ギガパスカル）以上、温度
は１３５０℃以上で行わなければならない。The weight ratio of Co as a binding metal and diamond can be variously changed according to the application conditions, and the diamond can be selected in a weight ratio of 50 to 98%. In order to have wear resistance as a cutting tool, 50% or more of diamond is required, and in order to maintain toughness as a sintered body tool, diamond must be 98% or less. Further, in order to strengthen the binder phase, S which is an element forming a precipitation hardening type Co-based intermetallic compound
One or more of i, Ti, Zr, and Mo are added in an amount of 0.5 to 6% by weight. In this case, 0.5% or less has no effect, and 6% or more reduces toughness. As the method for producing the sintered body of the present invention, diamond having the above composition and C
o and the additive element powder are blended in a predetermined ratio and mixed by a ball mill or the like, and the mixture is powdered, or after compaction molding, in a vacuum to remove adsorbed water and the like in the mixing process.
It is dried at 0 to 700 ° C. and sintered under a condition of ultrahigh pressure and high temperature using a belt type or girdle type ultrahigh pressure apparatus. Basically, it is necessary to carry out the sintering conditions in the stable presence region of diamond, but it depends on the blending ratio of diamond and Co, and the pressure should be 5 GPa (5 Gpa) or higher and the temperature should be 1350 ° C. or higher. I won't.

【０００８】[0008]

【実施例】【Example】

（実施例 １）平均粒度５μｍのダイヤモンド粉末と平
均粒度１μｍのＣｏ，Ｓｉの各粉末を重量で各々８５
％、１２％、３％の割合に配合し、ｎ−ヘキサンを加え
てボールミルで充分混合した。この混合粉末を真空炉で
１０^-5Ｔｏｒｒの減圧下で６００℃に３時間加熱して乾
燥した。圧力媒体としては、パイロフィライト、ヒータ
ーとしては、黒鉛を用い、黒鉛と試料の間には、ＮａＣ
ｌ成形体を充填した。なお、試料は、粉末状で外径１
５．８ｍｍ，高さ２．５ｍｍの円板形スペースを占めて
いる。まず圧力を５．５ＧＰａに上げ、ついで温度を１
５００℃に上げ３０分間保持した。保持後温度を下げ圧
力を徐々に下ろした。得られた円板形焼結体は、外径約
１４ｍｍ、厚さ１．９ｍｍであった。これをダイヤモン
ド砥石とペーストを用いて研磨して焼結体の硬度を測定
したところ、ＨＶ７５００であった。焼結体をダイヤモ
ンド砥石で研削してシェルエンドミルを作成し、切削テ
ストを行った。比較用としてダイヤモンドの平均粒度が
１０μｍで結合材にＣｏを用いた市販焼結体を使用し
た。切削テスト結果は、第１図に示すとおり市販の焼結
体（Ｃｏを結合材とした）より良好な性能が得られた。(Example 1) Diamond powder having an average particle size of 5 μm and Co and Si powders having an average particle size of 1 μm were 85 by weight, respectively.
%, 12%, 3%, n-hexane was added, and they were thoroughly mixed by a ball mill. The mixed powder was dried in a vacuum oven under reduced pressure of 10 ⁻⁵ Torr at 600 ° C. for 3 hours. Pyrophyllite was used as the pressure medium, graphite was used as the heater, and NaC was used between the graphite and the sample.
1 The molded body was filled. The sample is powder and has an outer diameter of 1
It occupies a disk-shaped space with a height of 5.8 mm and a height of 2.5 mm. First increase the pressure to 5.5 GPa and then increase the temperature to 1
The temperature was raised to 500 ° C. and kept for 30 minutes. After the holding, the temperature was lowered and the pressure was gradually lowered. The obtained disc-shaped sintered body had an outer diameter of about 14 mm and a thickness of 1.9 mm. When this was ground with a diamond grindstone and a paste and the hardness of the sintered body was measured, it was HV7500. The sintered body was ground with a diamond grindstone to create a shell end mill, and a cutting test was performed. For comparison, a commercially available sintered body having an average grain size of diamond of 10 μm and using Co as a binder was used. As a result of the cutting test, as shown in FIG. 1, better performance was obtained as compared with a commercially available sintered body (using Co as a binder).

【０００９】（実施例 ２）実施例１と同様の方法によ
り表１に示すような重量％のダイヤモンド，Ｃｏ，Ｓ
ｉ，Ｔｉ，Ｚｒ，Ｍｏの一部又は全部を配合成分とする
一連の焼結体を作製したところ、切削工具用ダイヤモン
ド焼結体として十分な高硬度が得られた。そして第２図
に示すように、ボーリングバイトを作製し切削テストを
行ったところ、表１に示すように、Ｊに示すＣｏを結合
材とした市販の焼結体及び、Ｋに示すＷｃ−Ｃｏを結合
材とした市販の焼結体、のいずれよりも良好な性能が得
られた。(Example 2) By the same method as in Example 1, diamond, Co, and S of the weight% shown in Table 1 were used.
When a series of sintered bodies containing a part or all of i, Ti, Zr, and Mo as a blending component was produced, a sufficiently high hardness was obtained as a diamond sintered body for a cutting tool. Then, as shown in FIG. 2, a boring bar was produced and a cutting test was conducted. As shown in Table 1, a commercially available sintered body containing Co as shown in J and a Wc-Co shown as K were obtained. The performance was better than that of any of the commercially available sintered bodies using as a binder.

【表１】 [Table 1]

【００１０】[0010]

【発明の効果】以上説明したように本発明によると、ダ
イヤモンドに対する触媒作用をなすものとしてＣｏを加
えると同時に、Ｃｏ系金属間化合物を形成する元素であ
る、Ｓｉ，Ｔｉ，Ｚｒ，Ｍｏの中より、１種または２種
以上を０．５〜６％添加し、Ｃｏ基地の分散強化により
高温強度の向上を図ることによって従来技術の課題を克
服した、非鉄材料、非金属等の重断続切削において、耐
熱性および高温特性にすぐれた高耐熱、高靱性ダイヤモ
ンド焼結体およびその製造法を提供するものとなった。
好ましくは結合相中にＣｏ系金属間化合物を析出させ、
Ｃｏ基地をより分散強化させてより高温強度の向上を図
ることができる。As described above, according to the present invention, among Si, Ti, Zr, and Mo, which are elements that form Co-based intermetallic compounds at the same time when Co is added as a catalyst for diamond, More than 0.5% to 6% of 1 type or 2 types or more is added, and the high-temperature strength is improved by strengthening the dispersion of the Co base to overcome the problems of the prior art. Heavy interrupted cutting of non-ferrous materials, non-metals, etc. In order to provide a high heat resistance and high toughness diamond sintered body having excellent heat resistance and high temperature characteristics, and a method for producing the same.
Preferably, a Co-based intermetallic compound is precipitated in the binder phase,
The Co base can be further dispersed and strengthened to improve the high temperature strength.

【図面の簡単な説明】[Brief description of drawings]

【図１】本発明の実施例１の切削テスト状態を示す説明
図である。FIG. 1 is an explanatory diagram showing a cutting test state according to a first embodiment of the present invention.

【図２】本発明の実施例２の切削テスト状態を示す説明
図である。FIG. 2 is an explanatory diagram showing a cutting test state of Example 2 of the present invention.

───────────────────────────────────────────────────── フロントページの続き (72)発明者 伊井 禎則 富山県富山市不二越本町一丁目１番１号株 式会社不二越内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Sadanori Ii 1-1-1, Fujikoshi Honcho, Toyama City, Toyama Prefecture Fujikoshinai Corporation

Claims (3)

【特許請求の範囲】[Claims] 【請求項１】 ダイヤモンドを重量％で５０〜９８％含
有し、残部が結合金属相からなり、前記結合金属相はＳ
ｉ，Ｔｉ，Ｚｒ，Ｍｏの中から選ばれた１種又は２種以
上の元素を重量％で０．５〜６％を含みかつ残余をＣｏ
からなることを特徴とする高耐熱、高靱性ダイヤモンド
焼結体。1. A diamond containing 50-98% by weight, the balance consisting of a bonding metal phase, said bonding metal phase being S
i, Ti, Zr, Mo, one or more elements selected from the range of 0.5 to 6% by weight and the balance Co
A highly heat-resistant, high-toughness diamond sintered body characterized by comprising 【請求項２】 前記結合金属相中に析出したＣｏ系金属
間化合物を含む請求項１に記載する高耐熱、高靱性ダイ
ヤモンド焼結体。2. The high heat resistant and high toughness diamond sintered body according to claim 1, which contains a Co-based intermetallic compound precipitated in the bonded metal phase. 【請求項３】 ダイヤモンド粉末を重量で５０〜９８
％、残部が金属粉末で、前記金属粉末は、Ｓｉ，Ｔｉ，
Ｚｒ，Ｍｏの中から選ばれた１種又は２種以上の金属粉
末を重量％で０．５〜６％含みかつ残余をＣｏ金属粉末
とし、これら粉末を混合し、そして粉末状で又は圧粉成
形後、超高圧高温装置を用いて５ＧＰａ以上の高圧下で
１３５０℃以上の温度に加熱して焼結することを特徴と
する高耐熱、高靱性ダイヤモンド焼結体の製造法。3. Diamond powder in a weight of 50-98.
%, The balance is metal powder, and the metal powder is Si, Ti,
One or more metal powders selected from Zr and Mo are contained in an amount of 0.5 to 6% by weight and the rest is Co metal powders, and these powders are mixed and powdered or pressed. A method for producing a highly heat-resistant and high-toughness diamond sintered body, which comprises heating after sintering to a temperature of 1350 ° C. or higher under a high pressure of 5 GPa or higher using an ultrahigh-pressure high-temperature apparatus and sintering.