JP2769821B2 - TiCN-based cermet and method for producing the same - Google Patents

TiCN-based cermet and method for producing the same

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Publication number
JP2769821B2
JP2769821B2 JP63244885A JP24488588A JP2769821B2 JP 2769821 B2 JP2769821 B2 JP 2769821B2 JP 63244885 A JP63244885 A JP 63244885A JP 24488588 A JP24488588 A JP 24488588A JP 2769821 B2 JP2769821 B2 JP 2769821B2
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Prior art keywords
weight
nitrogen
carbide
phase component
temperature
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Japanese (ja)
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JPH0215139A (en
Inventor
範昭 建野
裕久 小西
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Kyocera Corp
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Kyocera Corp
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Classifications

    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C29/00—Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides
    • C22C29/02—Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides based on carbides or carbonitrides
    • C22C29/04—Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides based on carbides or carbonitrides based on carbonitrides
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F2998/00—Supplementary information concerning processes or compositions relating to powder metallurgy

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Powder Metallurgy (AREA)

Description

【発明の詳細な説明】 〔産業上の利用分野〕 本発明は耐摩耗性、靭性に優れた焼肌面が良好で且
つ、ポア、ボイドのないTiCN基サーメットおよびその製
法に関するもので、特に切削工具として有用なTiCN基サ
ーメットの改良に関する。Description: FIELD OF THE INVENTION The present invention relates to a TiCN-based cermet having excellent wear resistance and toughness, having a good burnt surface, and having no pores and voids, and a method for producing the same. Improvement of TiCN-based cermet useful as a tool.

〔従来技術〕(Prior art)

従来から、切削用焼結体としてはWC−Coを主成分とす
る超硬合金が主として用いられていたが、最近ではTiの
炭化物、窒化物、炭窒化物を主成分とするサーメット焼
結体が用いられている。Conventionally, cemented carbide mainly composed of WC-Co has been mainly used as a sintered body for cutting, but recently, a cermet sintered body mainly composed of carbides, nitrides and carbonitrides of Ti. Is used.

このようなサーメット系焼結体としては、TiCを主成
分とし、鉄族金属を結合相とし、さらに周期律表第IV
a、V a、VI a族金属の炭化物、窒化物、炭窒化物を硬質
相成分として加えたTiC基サーメットが主流であった。
しかし乍らこのようなTiC基サーメット焼結体では耐熱
性、強靭性に劣ることから、上記組成にさらにTiN等の
窒化物、炭窒化物を含有させることが提案された。これ
は、TiN自体が靭性に富むことにより、焼結体に靭性を
付与するとともに、熱伝導率が高いことにより、耐熱衝
撃性、耐熱塑性変形性を向上させようとするものであ
る。Such a cermet-based sintered body includes TiC as a main component, an iron group metal as a binder phase, and
The mainstream was a TiC-based cermet to which carbides, nitrides, and carbonitrides of a, Va, and VIa group metals were added as hard phase components.
However, since such a TiC-based cermet sintered body is inferior in heat resistance and toughness, it has been proposed to further include a nitride such as TiN or a carbonitride in the above composition. This is intended to impart toughness to the sintered body due to richness of TiN itself and to improve thermal shock resistance and thermal plastic deformation due to high thermal conductivity.

一方、元来、サーメットは製法上表面に金属が浸み出
すとともにその直下に硬質な層が存在し、切削性能上欠
損を起こし易いという欠点を有している。On the other hand, cermets originally have a drawback in that metal is leached on the surface in the production process and a hard layer exists immediately below the surface, which easily causes a defect in cutting performance.

そこで、従来よりTiNを含有するTiC基サーメットに対
し、さらに各種の改良がなされている。Therefore, various improvements have been made to the TiC-based cermet containing TiN.

例えば特公昭59−14534号では液相出現温度以下で窒
素を炉内に導入し、焼結体表面に靭性に富む軟化層を形
成させることがまた、特公昭59−17176号ではCO還元雰
囲気で焼成することにより、特定の硬度を有する硬質層
を形成させることが、さらに、特公昭60−34618号によ
れば、焼成後の降温時にCO雰囲気と成すことにより表面
内部とも均一な機械特性を有するサーメットを得ること
が提案されている。For example, in Japanese Patent Publication No. Sho 59-14534, nitrogen is introduced into the furnace at a temperature lower than the liquid phase appearance temperature to form a softened layer with high toughness on the surface of the sintered body. By firing, it is possible to form a hard layer having a specific hardness.Furthermore, according to Japanese Patent Publication No. 60-34618, when the temperature is lowered after firing, a CO atmosphere is formed to have uniform mechanical properties inside the surface. It is proposed to get a cermet.

〔発明が解決しようとする問題点〕[Problems to be solved by the invention]

しかし乍ら、前記先行技術によれば、硬度あるいは靭
性のいずれかについてのみ検討されるにとどまり、高硬
度および高靭性の双方を必要とする工具用材料としては
切削性能の上で未だ不十分である。However, according to the prior art, only the hardness or the toughness is studied only, and as a tool material requiring both high hardness and high toughness, it is still insufficient in cutting performance. is there.

また、TiN等の窒化物を含有する系では、TiN自体が鉄
族金属との濡れ性が悪いことに起因し、焼結性が低下す
るという欠点を有するとともに、TiN自体が高温域で分
解し易いことから焼結体中にポア、ボイドが発生し易い
等の欠点を有するがこの点についても充分検討されてお
らず、切削特性に対する信頼性が低いという問題を有し
ている。In addition, a system containing a nitride such as TiN has the disadvantage that the sinterability is reduced due to poor wettability of the TiN itself with the iron group metal, and the TiN itself is decomposed in a high temperature region. Because of its easiness, it has disadvantages such as easy generation of pores and voids in the sintered body. However, this point has not been sufficiently studied, and there is a problem that the reliability of the cutting characteristics is low.

〔発明の目的〕[Object of the invention]

本発明は上述した欠点を解消することを主たる目的と
するものであり、具体的には窒素を多量に含む系におい
てポア、ボイドがなく、TiNの持つ特性を充分に発揮
し、耐熱性、耐摩耗性、靭性に優れ且つ、表面状態が良
好なTiCN基サーメットを得ることを目的とするものであ
る。An object of the present invention is to eliminate the above-mentioned drawbacks. Specifically, in a system containing a large amount of nitrogen, there are no pores and voids, and the properties of TiN are fully exhibited, and heat resistance and heat resistance are improved. It is an object of the present invention to obtain a TiCN-based cermet having excellent abrasion and toughness and a good surface condition.

〔問題点を解決するための手段〕[Means for solving the problem]

本発明者は上記欠点に対し研究を重ねた結果、窒素を
多量に含むサーメットの成形体を焼成するに際し、特定
圧力の窒素ガスを炉内に特定の昇温過程で導入すること
により、TiNの分解を抑制しつつ、焼結を進行させるこ
とができ、それにより前記目的が達成されることを知見
した。The present inventor has conducted studies on the above disadvantages.As a result, when sintering a cermet compact containing a large amount of nitrogen, by introducing nitrogen gas at a specific pressure into the furnace in a specific heating process, TiN It has been found that sintering can proceed while suppressing decomposition, thereby achieving the above object.

即ち、本発明は、Tiを炭化物、窒化物あるいは炭窒化
物換算で50乃至80重量％、周期律表第VI a族元素を炭化
物換算で10乃至40重量％の割合で含有するとともに（窒
素／炭素＋窒素）で表される原子比が0.4乃至0.6の範囲
内にある硬質相成分70乃至90重量％と、鉄族金属から成
る結合相成分10乃至30重量％とから成る成形体を真空炉
内に設置後、昇温し、鉄族金属による液相出現温度以上
で１乃至30torrの圧力の窒素ガスを導入し、焼結最高温
度到達後、該窒素ガス圧力を減圧して焼成することによ
り、焼肌面の最大表面粗さが3.5μｍ以下、有孔度がＡ
−１以下で、且つ表面から1000μｍまでの表層部に内部
よりも高靭性、高硬度の改質部が存在するTiCN基サーメ
ットを得るものである。That is, the present invention contains 50 to 80% by weight of Ti, in terms of carbide, nitride or carbonitride, and 10 to 40% by weight, in terms of carbide, of a Group VIa element in the periodic table (Nitrogen / Nitrogen). A compact formed of 70 to 90% by weight of a hard phase component having an atomic ratio represented by (carbon + nitrogen) in the range of 0.4 to 0.6 and 10 to 30% by weight of a binder phase component composed of an iron group metal is placed in a vacuum furnace. After the temperature is increased, the temperature is raised, and nitrogen gas having a pressure of 1 to 30 torr is introduced at a temperature higher than the liquid phase appearance temperature of the iron group metal, and after reaching the maximum sintering temperature, the nitrogen gas pressure is reduced and firing is performed. The maximum surface roughness of the burnt skin is 3.5 μm or less, and the porosity is A
The present invention is to obtain a TiCN-based cermet in which a modified portion having a toughness and a hardness higher than −1 is present in the surface layer portion of −1 or less and from the surface to 1000 μm from the inside.

以下、本発明を詳述する。 Hereinafter, the present invention will be described in detail.

本発明のTiCN基サーメットは硬質相成分として、Tiを
炭化物、窒化物あるいは炭窒化物換算で50乃至80重量
％、特に55乃至65重量％とW,Mo等の周期率表第VI a族元
素を炭化物換算で10乃至40重量％、特に15乃至30重量％
とを含有する。The TiCN-based cermet of the present invention contains Ti as a hard phase component in an amount of 50 to 80% by weight, particularly 55 to 65% by weight in terms of carbide, nitride or carbonitride. 10 to 40% by weight, especially 15 to 30% by weight in terms of carbide
And

このような硬質相成分において、Tiの量が50重量％を
下回ると耐摩耗性が低下し、80重量％を越えると焼結性
が低下し好ましくない。また、第VI a族元素は粒成長抑
制、結合相との濡れ性を向上させる効果を有するが、10
重量％を下回ると上記効果が得られず、硬質相が粗大化
し、硬度、強度が低下する。また、40重量％を越えると
η相等の不健全相が生じると共に焼結が困難となる。In such a hard phase component, if the amount of Ti is less than 50% by weight, the wear resistance decreases, and if it exceeds 80% by weight, the sinterability decreases, which is not preferable. Group VIa elements have the effect of suppressing grain growth and improving wettability with the binder phase.
If the amount is less than 10% by weight, the above effect cannot be obtained, the hard phase becomes coarse, and the hardness and strength are reduced. If the content exceeds 40% by weight, an unhealthy phase such as an η phase is generated, and sintering becomes difficult.

また、硬質相成分としては上記の外、耐クレータ摩耗
性向上を目的としてTa,Nbを、さらに耐塑性変形性向上
を目的としてZr,V,Hf等を窒化物、炭化物、炭窒化物と
して５乃至40重量％の割合で含むことも可能であるが、
40重量％を越えると耐摩耗性劣化、ポア、ボイドの発生
が著しく増加する傾向にあり好ましくない。As the hard phase component, in addition to the above, Ta, Nb for the purpose of improving crater wear resistance, and Zr, V, Hf, etc., for the purpose of improving plastic deformation resistance, are used as nitrides, carbides, and carbonitrides. Although it is possible to include it in a proportion of about 40% by weight,
If it exceeds 40% by weight, deterioration of wear resistance and generation of pores and voids tend to increase remarkably, which is not preferable.

一方、結合相はFe,CO,Ni等の鉄族金属を主体として成
るもので、一部、硬質相形成成分が含まれる場合もあ
る。On the other hand, the binder phase is mainly composed of an iron group metal such as Fe, CO, and Ni, and may partially include a hard phase forming component.

焼結体全体として硬質相成分は70乃至90重量％、結合
相成分は10〜30重量％の割合からなる。The hard phase component is 70 to 90% by weight and the binder phase component is 10 to 30% by weight in the whole sintered body.

本発明における大きな特徴は、硬質相成分中において
（窒素／炭素＋窒素）で表わされる原子比が0.4乃至0.
6、特に0.4〜0.5の範囲に設定される点にある。即ち、
この原子比が0.4を下回ると靭性、耐摩耗性の向上が望
めず、本発明の目的が達成されず、0.6を越えると焼結
体中にポア、ボイドが発生し、工具としての信頼性が低
下する。A major feature of the present invention is that the hard phase component has an atomic ratio represented by (nitrogen / carbon + nitrogen) of 0.4 to 0.4.
6, especially in the range of 0.4 to 0.5. That is,
If the atomic ratio is less than 0.4, improvement in toughness and wear resistance cannot be expected, and the object of the present invention cannot be achieved.If the atomic ratio exceeds 0.6, pores and voids are generated in the sintered body, and the reliability as a tool is reduced. descend.

また、本発明のサーメットの他の特徴は窒素量が前述
したように多量であるにもかかわらず、内部にポア、ボ
イドが実質的に存在せず、焼結体の焼肌面が非常になだ
らかでその最大表面粗さが3.5μｍ以下である。ポア、
ボイドの存在は超硬工具協会規格「超硬合金の有孔度分
類標準」（CIS−006−1966）によればＡ−１以下のレベ
ルである。Another feature of the cermet of the present invention is that although the amount of nitrogen is large as described above, pores and voids are not substantially present inside, and the burning surface of the sintered body is very gentle. And the maximum surface roughness is 3.5 μm or less. Pore,
The presence of voids is at a level of A-1 or less according to the Carbide Tool Association standard “Cemented Carbide Porosity Classification Standard” (CIS-006-1966).

本発明のサーメットはこのような構成により、窒素を
多量に含むことによる靭性、耐摩耗性、耐熱性の向上効
果を長期に亘り維持することができ、工具として長寿命
化、高信頼性を図ることが可能となる。しかも焼結後の
焼結体に対し研摩工程等を行うことなく、製品化するこ
とも可能となる。さらに、本発明のサーメットは第１図
および第２図に示すように表面から1000μｍまでの表層
部に内部より高硬度、高靭性の改質部が存在するという
特徴を有する。具体的には内部のビッカース硬度（荷重
20Kg）に対し５％以上、内部の靭性（KIC）に対し５％
以上高い特性を有する。この改質層の存在によって、従
来のサーメットと比較して切削工具としての耐摩耗性、
耐欠損性を大きく向上させることが可能となった。With such a configuration, the cermet of the present invention can maintain the effect of improving toughness, abrasion resistance, and heat resistance by containing a large amount of nitrogen for a long period of time, and achieve long life and high reliability as a tool. It becomes possible. In addition, it is possible to commercialize the sintered body without performing a polishing step or the like on the sintered body after sintering. Further, the cermet according to the present invention has a feature that, as shown in FIG. 1 and FIG. 2, a modified portion having higher hardness and toughness is present in the surface layer from the surface up to 1000 μm from the inside. Specifically, the internal Vickers hardness (load
5% or more with respect to internal toughness (K IC )
It has high characteristics. Due to the presence of this modified layer, wear resistance as a cutting tool compared to conventional cermets,
It has become possible to greatly improve the fracture resistance.

尚、通常、焼結体の表面部には金属のしみ出しが認め
られるが、このようなしみ出しは耐摩耗性を低下させる
傾向にあるため、極力薄く設定する必要があり、特に５
μｍ以下に抑えることが望ましい。In general, exudation of metal is observed on the surface of the sintered body. However, since such exudation tends to reduce wear resistance, it is necessary to set the thickness as thin as possible.
It is desirable to keep the thickness below μm.

本発明のTiCN基サーメットの製造方法によれば、組成
としてTiを炭化物、窒化物あるいは炭窒化物換算で50乃
至80重量％、周期律表第VI a族元素を炭化物換算で10乃
至40重量％の割合で含有するとともに（窒素／炭素＋窒
素）で表わされる原子比が0.4乃至0.6の範囲内にある硬
質相成分70乃至90重量％と、結合相10乃至30重量％とか
ら成る成形体を作成する。According to the method for producing a TiCN-based cermet of the present invention, Ti is 50 to 80% by weight in terms of carbide, nitride or carbonitride, and 10 to 40% by weight of Group VIa element in the periodic table in terms of carbide. Of a hard phase component having an atomic ratio of (Nitrogen / Carbon + Nitrogen) in the range of 0.4 to 0.6 and a binder phase of 10 to 30% by weight. create.

具体的には原料粉末としてTiC,TiN,TiCN等を、また第
VI a族系としてはWC,Mo2C,MoC等を、あるいはこれらの
複合炭化物、複合炭窒化物を用い、上記の組成となるよ
うに調合した後、公知の成形手段、例えばプレス成形、
押出し成形、鋳込み成形、射出成形、冷間静水圧成形等
で成形する。Specifically, TiC, TiN, TiCN, etc. are used as raw material powders.
As a VIa-group system, WC, Mo 2 C, MoC, or the like, or a composite carbide thereof, using a composite carbonitride, after blending so as to have the above composition, known molding means, for example, press molding,
It is formed by extrusion molding, casting molding, injection molding, cold isostatic molding, or the like.

この時、前述したようにTA,Nb,Zr,V,Hf等の炭化物、
窒化物、炭窒化物等を組合わせて用いることも当然可能
である。なお、Ti系としてはTiCを用いると焼結性が低
下し、部分的粒成長を起こす場合があるため、Ti（CN）
あるいはTi（CN）とTiNとの組合せがより好ましい。At this time, as described above, carbides such as TA, Nb, Zr, V, Hf,
Naturally, it is also possible to use a combination of nitrides, carbonitrides and the like. When TiC is used as the Ti-based material, the sinterability is reduced and partial grain growth may occur.
Alternatively, a combination of Ti (CN) and TiN is more preferable.

得られた成形体は真空炉内に設定し、焼成に移され
る。The obtained compact is set in a vacuum furnace and transferred to firing.

本発明によれば、0.5Torr以下の真空炉内で加熱し、
所定の時期に１乃至30Torrの圧力の窒素ガスを導入す
る。この窒素ガスの導入によって成形体中に含まれるTi
N等の窒化物の熱分解を抑制し、熱分解に伴うポア、ボ
イドの発生を防止するものである。According to the present invention, heating in a vacuum furnace of 0.5 Torr or less,
At a predetermined time, nitrogen gas having a pressure of 1 to 30 Torr is introduced. The Ti contained in the compact by the introduction of this nitrogen gas
It suppresses the thermal decomposition of nitrides such as N and prevents the generation of pores and voids due to the thermal decomposition.

本発明によれば、この窒素ガス導入時期が特に重要で
ある。通常昇温過程において鉄族金属の液相出現温度付
近で緻密化が始まる。本発明によれば、この液相出現温
度以上、特に対理論密度比が初期の成形体よりも５％以
上緻密化した段階で導入する。５％以上緻密化した段階
とは、液相出現温度以上で成形体の表面には液相により
表面に被膜が形成される。この被膜形成後に窒素ガスを
導入することにより、成形体中に存在する空隙に窒素ガ
スが残留し、結果的にポア、ボイドを形成するのを防止
するためである。According to the present invention, the timing of introducing the nitrogen gas is particularly important. Normally, densification starts around the liquid phase appearance temperature of the iron group metal in the temperature rising process. According to the present invention, it is introduced at a stage where the density is higher than the liquid phase appearance temperature, in particular, the ratio of the theoretical density to the initial compact is 5% or more. The stage of densification of 5% or more means that a film is formed on the surface of the molded body by the liquid phase at a temperature not lower than the liquid phase appearance temperature. By introducing nitrogen gas after the formation of the film, it is possible to prevent the nitrogen gas from remaining in the voids existing in the molded body, thereby preventing the formation of pores and voids.

しかし、窒素ガス導入の時期が対理論密度比90％を越
えた付近では、実質上、窒化物の分解抑制効果は得られ
ず、焼結体表面に荒れが生じ易くなるため、90％以下の
密度の段階で導入することが望ましい。However, when the nitrogen gas introduction time exceeds about 90% of the theoretical density ratio, the effect of suppressing the decomposition of the nitride is not substantially obtained, and the surface of the sintered body is easily roughened. It is desirable to introduce at the stage of density.

窒素ガスは炉内の温度が焼結最高温度に達した後は、
該窒素ガスの圧力を先に設定した圧力よりも減圧し、真
空に戻すか、徐々に圧力を降下させながら焼成する。After the temperature inside the furnace reaches the maximum sintering temperature,
The pressure of the nitrogen gas is reduced from the previously set pressure, and the pressure is returned to a vacuum, or firing is performed while gradually reducing the pressure.

これは、焼結最高温度到達後にさらに圧力を上げる
と、焼結体表面部に粗粒で金属をほとんど含有しない、
脆い窒化層が生成され、焼肌面の荒れを生じるととも
に、表面部の靭性を著しく低下させてしまう。This means that if the pressure is further increased after reaching the maximum sintering temperature, the sintered body surface contains almost no metal with coarse particles,
A brittle nitride layer is generated, causing roughening of the burnt surface and significantly reducing the toughness of the surface.

なお、窒素ガス圧力を１乃至30Torrに限定した理由は
1Torr未満では窒化物に対する分解抑制効果が得られ
ず、30Torrを超えると焼結性が低下するとともに遊離炭
素が析出することもあり、焼結体の靭性が低下する。The reason for limiting the nitrogen gas pressure to 1 to 30 Torr
If the pressure is less than 1 Torr, the effect of suppressing the decomposition of nitrides cannot be obtained. If the pressure exceeds 30 Torr, the sinterability is reduced and free carbon may be precipitated, and the toughness of the sintered body is reduced.

このような製造方法によって、焼結体中のポア、ボイ
ドを実質的に皆無となすとともに表面状態をなめらかな
ものにすることができる。By such a manufacturing method, pores and voids in the sintered body can be substantially eliminated, and the surface state can be made smooth.

上記の製造方法によれば、前述したように焼結体の表
面層に高硬度、高靭性の改質部が形成されるという特異
的性質をもつ。この理由は定かではないが、次のように
考察される。According to the above-described manufacturing method, as described above, the sintered body has a specific property that a modified portion having high hardness and high toughness is formed on the surface layer. The reason for this is not clear, but is considered as follows.

窒素ガス導入後、成形体内部と炉内雰囲気との間に圧
力が生じている。それにより、成形体表面付近の結合金
属が内部に移動し、表面層付近は内部に対し、結合相量
が減少することにより、硬度が高くなる。それと同時に
組織上、表面付近の結晶が球状化すること、および第VI
a族元素が多量に含まれることにより靭性が向上するも
のと考えられる。After the introduction of the nitrogen gas, a pressure is generated between the inside of the compact and the atmosphere in the furnace. As a result, the bonding metal near the surface of the molded body moves inside, and the hardness increases near the surface layer by reducing the amount of the bonding phase with respect to the inside. At the same time, on the structure, crystals near the surface are spheroidized, and
It is considered that the toughness is improved by containing a large amount of group a elements.

本発明は切削用工具として用いられるあらゆる形状の
ものに適用できるものであるが、その形状の複雑化に伴
い焼結時の収縮速度を制御することが望ましい。The present invention can be applied to any shape used as a cutting tool, but it is desirable to control the shrinkage speed during sintering as the shape becomes more complicated.

即ち、複雑形状の成形体には、その成形方法にもよる
が、通常、成形体中で生密度のバラツキが生じている。
そのため、焼結中の成形体の収縮曲線に差異があるた
め、最終焼結体の表面に微細なポアやクラックが生じる
恐れがある。That is, although a molded article having a complicated shape depends on the molding method, the green density usually varies in the molded article.
Therefore, since there is a difference in the shrinkage curve of the compact during sintering, fine pores and cracks may be generated on the surface of the final sintered body.

このような現象を防止するためには、焼結時の収縮速
度を緩やかにすることが必要である。収縮速度を緩やか
にする方法としては、昇温速度を緩かにする方法が考え
られるが、この場合は窒化物を多量に含む本発明の系で
は高温に瀑される時間が長くなるため、窒化物の分解が
生じポア、ボイドが生成されてしまう。他の方法として
は窒素の導入を低温より行うことによって上記の窒化物
分解を抑制することも可能であるが、この場合は前述し
た通り、窒素ガスが焼結体内部にトラップされ、ポア、
ボイドが発生する。In order to prevent such a phenomenon, it is necessary to slow down the shrinkage speed during sintering. As a method of slowing down the shrinkage rate, a method of slowing down the heating rate can be considered, but in this case, in the system of the present invention containing a large amount of nitride, the time of falling to high temperature becomes long, The substance is decomposed and pores and voids are generated. As another method, it is possible to suppress the above-mentioned nitride decomposition by introducing nitrogen at a low temperature, but in this case, as described above, nitrogen gas is trapped inside the sintered body, and pores,
Voids occur.

本発明によれば、前述した時期に窒素ガスを導入する
に際し、予め、He,Ar等の不活性ガスを導入することに
よって焼結性を阻害することなく、窒化物の分解を抑制
し、収縮をなだらかに進行させることができる。According to the present invention, when introducing the nitrogen gas at the above-mentioned time, in advance, without impairing the sinterability by introducing an inert gas such as He, Ar, to suppress the decomposition of the nitride, shrinkage Can proceed smoothly.

不活性ガスは、窒素ガス導入温度よりおよそ50〜200
℃低い温度で導入する。その圧力は、１気圧以下である
ことが望ましい。Inert gas is about 50 to 200
Introduce at a lower temperature. The pressure is desirably 1 atm or less.

このような操作は特に３次元ブレーカ等に特に有用で
ある。Such an operation is particularly useful for a three-dimensional breaker or the like.

〔実施例１〕 原料粉末として平均粒径１〜1.5μｍのTi（CN）,TiN,
TiC,WC,Mo2O,NbC,NbN,VC,Ni,Coを用い、第１表の組成に
調合後、振動ミルが粉砕を行い、バインダーを添加した
ものをTNGA332チップ形状にプレス成形し、300℃で脱バ
インダー後、第１表の仕様で焼成を行った。[Example 1] Ti (CN), TiN, having an average particle size of 1 to 1.5 µm as raw material powders
Using TiC, WC, Mo 2 O, NbC, NbN, VC, Ni and Co, after mixing to the composition shown in Table 1, the vibration mill was crushed, and the one with the binder added was pressed into a TNGA332 chip shape, After debinding at 300 ° C., firing was performed according to the specifications shown in Table 1.

また、同時に抗折試験用のサンプルも作成した。 At the same time, samples for bending test were prepared.

得られた焼結体に対し、硬質相の炭素、窒素を定量分
析し、（N/C＋Ｎ）原子比を求めた。また、焼肌面に対
し、最大表面粗さ（Rmax）を調べるとともに研摩面にお
けるボイド・ポアの存在を超硬工具協会規格「超硬合金
の有孔度分類標準」（CIS−006−1966）によって目視観
察し、Ａ−１〜６のランク付を行った。The obtained sintered body was quantitatively analyzed for carbon and nitrogen in the hard phase, and the (N / C + N) atomic ratio was determined. In addition, the maximum surface roughness (Rmax) of the burnt surface is examined, and the presence of voids and pores on the polished surface is determined by the Cemented Carbide Tool Association standard "Cemented Carbide Porosity Classification Standard" (CIS-006-1966). And A-1 to 6 were ranked.

また、抗折試験用サンプルでJISR1601に従い、３点曲
げ抗折強度を測定した。In addition, a three-point bending strength was measured on a bending test sample according to JISR1601.

さらに、焼結体内部のビッカース硬度Hv（荷重20Kg）
およびビッカース硬度用ダイヤモンド圧子を用い、荷重
20Kgで圧痕法により破壊靭性（KIC）を測定した。Furthermore, Vickers hardness Hv inside the sintered body (load 20Kg)
And a diamond indenter for Vickers hardness
Fracture toughness (K IC ) was measured at 20 kg by the indentation method.

なお、試料No.1,2,6,8については試料を約20゜で研摩
し、該研摩面に対し垂直方向でビッカース硬度、破壊靭
性を表面からの距離（即ち、深さ）を変えて測定した。
結果は第１図および第２図に示す。For samples Nos. 1, 2, 6, and 8, the samples were polished at about 20 mm, and the Vickers hardness and fracture toughness were changed in the direction perpendicular to the polished surface by changing the distance from the surface (that is, the depth). It was measured.
The results are shown in FIG. 1 and FIG.

各試料に対し、下記条件で耐摩耗試験、耐欠損試験を
行い、耐摩耗試験ではフランク摩耗量（mm）クレータ摩
耗量（mm）を測定し、耐欠損試験では、送りを0.2mm/re
vより0.05mm/revずつ上げ欠損を生じる送りを測定し
た。Abrasion resistance test and fracture resistance test were performed on each sample under the following conditions. In the wear resistance test, the flank wear amount (mm) and crater wear amount (mm) were measured. In the fracture resistance test, the feed rate was 0.2 mm / re.
The feed which caused a defect by raising by 0.05 mm / rev from v was measured.

摩耗試験方法 被削材 SCM435（丸棒Hs−40） 切削速度 200m/min 切り込み 2mm 送り 0.3mm/rev 切削時間 10min 工具形状 TNGA 332 耐欠損試験 被削材 SCM435（丸棒Hs−40） ４ツ購入 切削速度 100m/min 切削時間 1min 切り込み 2mm 形状 TNGA332 送り 0.2mm/rev〜 第１表および第２表の結果によれば、（N/C＋Ｎ）原
子比が0.4を下回るNo.6の試料は、内部の硬度（Hv）が
低く、表面部には顕著な高硬度、高靭性の改質部は形成
されず、切削テストにおいても、耐摩耗性、耐欠損性に
劣るものであった。逆に（N/C＋Ｎ）比が0.6を超えるN
o.7の試料では、焼結体内部にポア、ボイドが多くみら
れ、ほとんど信頼性に欠けるものであった。Abrasion test method Work material SCM435 (Round bar Hs-40) Cutting speed 200m / min Depth of cut 2mm Feed 0.3mm / rev Cutting time 10min Tool shape TNGA 332 Fracture resistance test Work material SCM435 (Round bar Hs-40) Purchase 4 Cutting speed 100m / min Cutting time 1min Depth of cut 2mm Shape TNGA332 Feed 0.2mm / rev ~ According to the results of Tables 1 and 2, the No. 6 sample having an (N / C + N) atomic ratio of less than 0.4 has a low internal hardness (Hv), and has a remarkably high hardness and high hardness on the surface. No modified portion of toughness was formed, and the cutting test was inferior in wear resistance and fracture resistance. Conversely, N whose (N / C + N) ratio exceeds 0.6
In the sample of o.7, many pores and voids were found inside the sintered body, and it was almost unreliable.

また、N2ガス導入後、圧力を増加させたNo.8の試料で
は表面窒化層が形成され、焼結体表面に荒れが生じ、切
削テストの結果も十分な特性を有していない。しかも表
面部のKICは大きく低下する傾向にあった。Further, in the sample of No. 8 in which the pressure was increased after the introduction of the N 2 gas, the surface nitrided layer was formed, the surface of the sintered body was roughened, and the results of the cutting test did not have sufficient characteristics. Moreover K IC of the surface portion tended to decrease significantly.

導入する窒素圧力が30Torrを超えるNo.9では、焼結体
内部にポアが生じ、信頼性に欠ける。In the case of No. 9 where the nitrogen pressure to be introduced exceeds 30 Torr, pores are generated inside the sintered body, and the reliability is poor.

窒素を導入しないNo.10では、表面の窒化物の分解に
よるとみられる荒れがひどく、切削テストにおいても良
好な結果は得られなかった。In the case of No. 10 in which nitrogen was not introduced, the roughness which was considered to be due to the decomposition of the nitride on the surface was severe, and good results were not obtained in the cutting test.

窒素ガスの導入を液相出現温度前で行ったNo.11の試
料は窒素ガスが焼結体内部にトラップされ、ポア、ボイ
ドが多数見られた。また、窒素ガスの導入が焼結最高温
度後では表面荒れが生じた。In the sample of No. 11 in which nitrogen gas was introduced before the appearance of the liquid phase, nitrogen gas was trapped inside the sintered body, and many pores and voids were observed. In addition, the introduction of nitrogen gas resulted in surface roughness after the maximum sintering temperature.

このような比較例に対し、本発明の試料はいずれも表
面粗さ（Rmax）3.5μｍ以下、ポア、ボイドがＡ−１以
下で優れた焼結性を示した。しかも特性上も高い靭性、
硬度を示した。なお、これらにはいずれも表面から10μ
ｍ間に内部（表面からほぼ0.1mm）の硬度に対し、５％
以上、靭性値に対し、５％以上の高硬度高靭性な部分が
形成されていた。In contrast to such comparative examples, the samples of the present invention all exhibited excellent sinterability with a surface roughness (Rmax) of 3.5 μm or less, pores and voids of A-1 or less. Moreover, high toughness in characteristics,
Hardness was indicated. In addition, each of these is 10μ from the surface
5% for the hardness of the inside (almost 0.1mm from the surface) between m
As described above, a high hardness and toughness portion of 5% or more with respect to the toughness value was formed.

また、本発明の試料は切削テストにおいてフランク摩
耗2.2（mm）以下、クレータ摩耗20（mm）以下、欠損試
験で送り0.50mm/revまで欠損が生じないもので切削工具
用として優れたサーメットであることが認識された。In addition, the sample of the present invention is a cermet excellent for cutting tools because it has a flank wear of 2.2 (mm) or less in a cutting test, a crater wear of 20 (mm) or less, and no breakage up to a feed of 0.50 mm / rev in a chipping test. It was recognized.

〔実施例２〕 組成がTiC0.5Ｎ0.550重量％、TiN8重量％、WC8重量
％、Mo2C10重量％、TaC12重量％、Ni6重量％、Co6重量
％の混合粉末を用い、実施例１と同様に調合し、３次元
ブレーカであるCNMG432HS形状にプレス成形し、第３表
に示す焼成条件で焼成を行い、焼結体表面のポアの存在
およびクラックの存在を観察した。[Example 2] A mixed powder having a composition of TiC 0.5 N 0.5 50% by weight, TiN 8% by weight, WC 8% by weight, Mo 2 C 10% by weight, TaC 12% by weight, Ni 6% by weight, and Co 6% by weight was used. The mixture was similarly prepared, press-molded into a CNMG432HS shape as a three-dimensional breaker, fired under the firing conditions shown in Table 3, and the presence of pores and cracks on the surface of the sintered body was observed.

この結果によれば、複雑形状品であるCNMG432HS品で
は不活性ガスを何ら導入しない場合は表面のポアはＡ−
１以下のレベルではあるが、ポアの存在が認められ、一
部にはクラックが認められた。 According to this result, in the case of the CNMG432HS product having a complicated shape, the pore on the surface is A-
Although at a level of 1 or less, the presence of pores was observed, and some cracks were observed.

これに対し、不活性ガス導入によってこれらのポア、
クラックはほぼ皆無とすることができた。しかしながら
不活性ガス導入時期がN2ガス導入温度以上ではほとんど
効果がなかった。On the other hand, by introducing inert gas, these pores,
Cracks could be almost eliminated. However, there was almost no effect when the inert gas introduction time was higher than the N 2 gas introduction temperature.

〔発明の効果〕〔The invention's effect〕

以上、詳述した通り、本発明によれば、窒素を多量に
含む系であるにかかわらず、ポア、ボイドの発生を充分
に抑制し、窒素含有により靭性、耐摩耗性、耐熱性の効
果を充分に発揮することが可能となり、工具としての長
期的信頼性を得ることができる。As described above in detail, according to the present invention, irrespective of the system containing a large amount of nitrogen, the generation of pores and voids is sufficiently suppressed, and the toughness, wear resistance, and heat resistance of nitrogen are reduced. It is possible to exert the effect sufficiently and to obtain long-term reliability as a tool.

しかも、焼結体の焼肌面が良好であることから、焼結
体に対し、表面研摩等を行うことなしに、製品化できる
とともにコストの低減等を図ることができる。In addition, since the surface of the sintered body is good, the sintered body can be commercialized and reduced in cost without performing surface polishing on the sintered body.

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

第１図は実施例No.1,2,6,8の試料における表面からの距
離と硬度との関係を示した図、第２図は同じく靭性との
関係を示した図である。FIG. 1 is a diagram showing the relationship between the distance from the surface and the hardness in the samples of Examples Nos. 1, 2, 6, and 8, and FIG. 2 is a diagram showing the relationship with the toughness.

───────────────────────────────────────────────────── フロントページの続き (58)調査した分野(Int.Cl.6，ＤＢ名) C22C 29/04 C22C 1/05──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. 6 , DB name) C22C 29/04 C22C 1/05

Claims (3)

(57)【特許請求の範囲】(57) [Claims] 【請求項１】Tiを炭化物、窒化物あるいは炭窒化物換算
で50乃至80重量％、周期律表第VI a族元素を炭化物換算
で10乃至40重量％の割合で含有するとともに（窒素／炭
素＋窒素）で表される原子比が0.4乃至0.6の範囲内にあ
る硬質相成分70乃至90重量％と、鉄族金属から成る結合
相成分10乃至30重量％とから構成され、焼肌面の最大表
面粗さが3.5μｍ以下、有孔度がＡ−１以下で、且つ表
面から1000μｍまでの表層部に内部よりも高靭性、高硬
度の改質部が存在することを特徴とするTiCN基サーメッ
ト。(1) containing 50 to 80% by weight of Ti as a carbide, nitride or carbonitride, and 10 to 40% by weight of a Group VIa element in the periodic table as a carbide (nitrogen / carbon); + Nitrogen) in a range of 0.4 to 0.6, and 70 to 90% by weight of a hard phase component and 10 to 30% by weight of a binder phase component composed of an iron group metal. TiCN base characterized by having a maximum surface roughness of 3.5 μm or less, a porosity of A-1 or less, and a toughness / hardness modified part higher than the inside in the surface layer up to 1000 μm from the surface cermet. 【請求項２】Tiを炭化物、窒化物あるいは炭窒化物換算
で50乃至80重量％、周期律表第VI a族元素を炭化物換算
で10乃至40重量％の割合で含有するとともに（窒素／炭
素＋窒素）で表される原子比が0.4乃至0.6の範囲内にあ
る硬質相成分70乃至90重量％と、鉄族金属から成る結合
相成分10乃至30重量％とから成る成形体を真空炉内に設
置後、昇温し、鉄族金属による液相出現温度以上で１乃
至30torrの圧力の窒素ガスを導入し、焼結最高温度到達
後、該窒素ガス圧力を減圧することを特徴とするTiCN基
サーメットの製法。(2) Ti is contained in an amount of 50 to 80% by weight in terms of carbide, nitride or carbonitride, and a Group VIa element of the periodic table in an amount of 10 to 40% by weight in terms of carbide (nitrogen / carbon). + Nitrogen) in a vacuum furnace with a hard phase component having an atomic ratio of 0.4 to 0.6 in the range of 0.4 to 0.6 and a hard phase component of 70 to 90 weight% and a binder phase component of iron group metal of 10 to 30 weight%. After the temperature is raised, a nitrogen gas having a pressure of 1 to 30 torr is introduced at a temperature higher than the liquid phase appearance temperature of the iron group metal, and after reaching the maximum sintering temperature, the nitrogen gas pressure is reduced. Manufacturing method of base cermet. 【請求項３】窒素ガス導入前に１気圧以下の不活性ガス
を導入する特許請求の範囲第２項記載のTiCN基サーメッ
トの製法。3. The method for producing a TiCN-based cermet according to claim 2, wherein an inert gas of 1 atm or less is introduced before introducing the nitrogen gas.
JP63244885A 1988-03-11 1988-09-29 TiCN-based cermet and method for producing the same Expired - Lifetime JP2769821B2 (en)

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JP5905188 1988-03-11
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Publication number Priority date Publication date Assignee Title
JP2828512B2 (en) * 1990-12-27 1998-11-25 京セラ株式会社 Coated TiCN-based cermet
JP2828511B2 (en) * 1990-12-27 1998-11-25 京セラ株式会社 Surface coated TiCN based cermet
US5403373A (en) * 1991-05-31 1995-04-04 Sumitomo Electric Industries, Ltd. Hard sintered component and method of manufacturing such a component
US5269452A (en) * 1992-11-12 1993-12-14 Northern Telecom Limited Method and apparatus for wirebonding
DE69433214T2 (en) * 1993-02-05 2004-08-26 Sumitomo Electric Industries, Ltd. Hard sintered alloy containing nitrogen
US6057046A (en) * 1994-05-19 2000-05-02 Sumitomo Electric Industries, Ltd. Nitrogen-containing sintered alloy containing a hard phase
DE69612376T2 (en) 1996-07-18 2001-07-12 Mitsubishi Materials Corp Blade made of titanium carbonitride cermet and blade made of coated cermet
SE511846C2 (en) * 1997-05-15 1999-12-06 Sandvik Ab Ways to melt phase a titanium-based carbonitride alloy
KR100409205B1 (en) * 2000-11-02 2003-12-12 김호태랑 Sauna device by using optical fiber
JP2004292905A (en) 2003-03-27 2004-10-21 Tungaloy Corp Compositionally graded sintered alloy and method of producing the same
JP2005194573A (en) * 2004-01-07 2005-07-21 Tungaloy Corp Cermet, coated cermet, and method for manufacturing them
JP5546120B2 (en) * 2008-11-26 2014-07-09 京セラ株式会社 Cermet throwaway tip
JP5559575B2 (en) 2009-03-10 2014-07-23 株式会社タンガロイ Cermet and coated cermet
US8784977B2 (en) 2009-06-22 2014-07-22 Tungaloy Corporation Coated cubic boron nitride sintered body tool
KR20120023179A (en) * 2009-06-30 2012-03-12 가부시키가이샤 탕가로이 Cermet and coated cermet
US8999531B2 (en) 2010-04-16 2015-04-07 Tungaloy Corporation Coated CBN sintered body
JP5392408B2 (en) 2010-07-06 2014-01-22 株式会社タンガロイ Coated cBN sintered body tool

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5757866A (en) * 1980-09-24 1982-04-07 Toshiba Tungaloy Co Ltd Hard alloy having nitride layer
ZA851091B (en) * 1984-02-27 1985-09-25 Goodyear Tire & Rubber The use of flat wire as a reinforcement in the belt package and carcass of a passenger tie

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