JP2018111108A - Composite member and cutting tool comprising the composite member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: a composite member which is made by bonding a WC-based hard metal and a WC-based hard metal via a bonding member and is excellent in a high temperature bonding strength; and a cutting tool.SOLUTION: A composite member is formed of an Sm diffusion layer onto a WC-based hard metal member from an interface between the WC-based hard metal member and a bonding part and is formed of a Co-Sm layer, a TiC layer and a Ti-Co layer on the bonding part by subjecting WC-based hard metal members to solid-liquid phase diffusion bonding with each other via a bonding member comprising a laminate of Sm deposition film-Ti foil-Sm deposition film. Therein, the Sm diffusion layer has an average layer thickness of 5 to 100 μm, the Co-Sm layer has an average composition of 20 to 80 atm% Co-20 to 80 atm% Sm, the TiC layer contains TiC of 90 atm% or more and the Ti-Co layer has an average composition of 45 to 75 atm%Ti-25 to 55 atm% Co. Further, a cutting tool comprising the composite member is also provided.SELECTED DRAWING: Figure 2

Description

本発明は、接合部の高温接合強度に優れた複合部材に関し、特に、ＷＣ基超硬合金とＷＣ基超硬合金とを接合した複合部材およびこの複合部材からなる切削工具に関する。   The present invention relates to a composite member excellent in high-temperature bonding strength of a joint portion, and more particularly, to a composite member obtained by joining a WC-based cemented carbide and a WC-based cemented carbide and a cutting tool made of the composite member.

従来から、工具材料としては、ＷＣ基超硬合金、ＴｉＣＮ基サーメット、ｃＢＮ焼結体等が良く知られているが、近年、工具材料を単一素材から形成するのではなく複合部材として工具材料を形成することが提案されている。   Conventionally, WC-based cemented carbide, TiCN-based cermet, cBN sintered body, and the like are well known as tool materials. However, in recent years, tool materials are not formed from a single material but as a composite member. Has been proposed to form.

例えば、特許文献１には、サーメット焼結体を第１の被接合材１とし、ｃＢＮ焼結体またはダイヤモンド焼結体を第２の被接合材３とする接合体であって、第１の被接合材および第２の被接合材の間に１０００℃未満では液相を生成しない接合材２（例えば、Ｔｉ、Ｃｏ、Ｎｉ）を介して接合し、該接合は０．１ＭＰａ〜２００ＭＰａの圧力で加圧しながら通電加熱することによって行うことが提案されており、これによって得られた接合体は、切削中に、ロウ材が液相を生成する温度を超える高温となっても、接合層の接合強度が低下することがないため、高速切削加工工具やＣＶＤコーティング切削工具として好適であるとされている。   For example, Patent Document 1 discloses a bonded body in which a cermet sintered body is a first material to be bonded 1 and a cBN sintered body or a diamond sintered body is a second material to be bonded 3. The joining material and the second joining material are joined via a joining material 2 (for example, Ti, Co, Ni) that does not generate a liquid phase at a temperature lower than 1000 ° C., and the joining is performed at a pressure of 0.1 MPa to 200 MPa. It has been proposed to perform heating by energization while pressurizing at a pressure, and the bonded body obtained by this can be used for the bonding layer even when the temperature of the brazing material becomes higher than the temperature at which the brazing material generates a liquid phase during cutting. Since the bonding strength does not decrease, it is considered suitable as a high-speed cutting tool or a CVD-coated cutting tool.

また、特許文献２には、超硬合金焼結体を第１の被接合材１とし、ｃＢＮ焼結体を第２の被接合材２とする接合体において、第１の被接合材および第２の被接合材の間にはチタン（Ｔｉ）を含有する接合材３を介して、少なくとも、第２の被接合材の背面と底面からなる２面で接合し、第２の被接合材と接合材との界面には、厚み１０〜３００ｎｍの窒化チタン（ＴｉＮ）化合物層を形成し、また、背面の接合層の厚みを、底面の接合層の厚みよりも薄くすることによって、接合強度が高い切削工具等の接合体を得ることが提案されている。   Patent Document 2 discloses a bonded body in which a cemented carbide sintered body is a first material to be bonded 1 and a cBN sintered body is a second material to be bonded 2. The two materials to be joined are joined to each other by at least two surfaces consisting of a back surface and a bottom surface of the second material to be joined, with a joining material 3 containing titanium (Ti), A titanium nitride (TiN) compound layer having a thickness of 10 to 300 nm is formed at the interface with the bonding material, and the bonding strength is reduced by making the thickness of the bonding layer on the back surface smaller than the thickness of the bonding layer on the bottom surface. It has been proposed to obtain a joined body such as a high cutting tool.

さらに、特許文献３には、ｃＢＮを２０〜１００質量％含むｃＢＮ焼結体と、Ｔｉ、Ｚｒ、Ｈｆ、Ｖ、Ｎｂ、Ｔａ、Ｃｒ、ＭｏおよびＷの炭化物、炭窒化物およびこれらの相互固溶体から成る群より選択された少なくとも１種からなる硬質相：５０〜９７質量％と、残部として、Ｃｏ、ＮｉおよびＦｅから成る群より選択された少なくとも１種を主成分とする結合相：３〜５０質量％とからなる硬質合金との複合体において、ｃＢＮ焼結体と硬質合金との間に接合層を設け、該接合層をセラミックス相と金属相とから構成し、さらに、該接合層の厚さを２〜３０μｍとすることによって、複合体の接合強度を高めることが提案されている。   Further, Patent Document 3 discloses a cBN sintered body containing 20 to 100% by mass of cBN, and carbides, carbonitrides, and mutual solid solutions of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W. Hard phase consisting of at least one selected from the group consisting of: 50 to 97% by mass, and the balance of the binder phase consisting mainly of at least one selected from the group consisting of Co, Ni and Fe: 3 to In a composite of 50% by mass of a hard alloy, a bonding layer is provided between the cBN sintered body and the hard alloy, and the bonding layer is composed of a ceramic phase and a metal phase. It has been proposed to increase the bonding strength of the composite by setting the thickness to 2 to 30 μm.

特開２００９−２４１２３６号公報JP 2009-241236 A 特開２０１２−１１１１８７号公報JP 2012-111187 A 特開２０１４−１３１８１９号公報JP 2014-131819 A

前記特許文献１〜３で提案された複合材料あるいはこれからなる切削工具は、通常条件の切削加工では、ある程度の性能を発揮するが、例えば、切れ刃に高負荷が作用し、かつ、高熱発生を伴う高送り、高切り込みの重切削条件では、高温接合強度が十分であるとはいえず、接合部からの破損が発生する問題があった。
そこで、切れ刃に高負荷が作用し、かつ、高熱発生を伴う重切削条件においても、接合部からの破断が生じないような、より高い高温接合強度を備えた接合部を有する複合部材およびこれからなる切削工具が望まれている。 The composite material proposed in Patent Documents 1 to 3 or a cutting tool made of the same exhibits a certain level of performance under normal conditions of cutting. For example, a high load acts on the cutting edge, and high heat generation occurs. Under the accompanying high feed and high cutting heavy cutting conditions, the high-temperature bonding strength cannot be said to be sufficient, and there has been a problem that breakage occurs from the bonded portion.
Therefore, a composite member having a joint portion having a higher high-temperature joint strength that causes a high load to act on the cutting edge and that does not cause breakage from the joint portion even under heavy cutting conditions with high heat generation, and A cutting tool is desired.

本発明者らは、前記従来の複合部材およびこれからなる切削工具の問題点を解決すべく、ＷＣ基超硬合金とＷＣ基超硬合金からなる複合部材およびこの複合材からなる切削工具、例えば、超高圧高温焼結時にｃＢＮ焼結体の焼結と同時にＷＣ基超硬合金（裏打ち材）を接合した複合焼結体からなる切刃部とＷＣ基超硬合金工具基体（台金）とを接合部材を介して接合した切削工具において、その接合部の接合強度を改善する方策について鋭意研究した結果、
一方のＷＣ基超硬合金部材と他方のＷＣ基超硬合金部材を、Ｔｉ箔の表面にＳｍ薄膜を蒸着した接合部材を介して接合し、一方のＷＣ基超硬合金部材と他方のＷＣ基超硬合金部材とが接合部によって接合された複合部材において、ＷＣ基超硬合金部材と接合部との界面からＷＣ基超硬合金の内部に向かって、ＷＣ基超硬合金の結合相中にＳｍが拡散した所定の平均層厚のＳｍ拡散層が形成され、また、ＷＣ基超硬合金部材と接合部との界面から接合部の厚さ方向中心側に向かって、Ｃｏ−Ｓｍ層、ＴｉＣ層及びＴｉ−Ｃｏ層が形成された接合部を設けることによって、ＷＣ基超硬合金部材と接合部との高温接合強度を向上させた複合部材が得られることを見出した。 In order to solve the problems of the conventional composite member and the cutting tool comprising the same, the present inventors have prepared a composite member comprising a WC-base cemented carbide and a WC-base cemented carbide and a cutting tool comprising the composite material, for example, A cutting edge portion made of a composite sintered body obtained by bonding a WC-based cemented carbide (backing material) and a WC-based cemented carbide tool base (base metal) simultaneously with sintering of a cBN sintered body during ultra-high pressure and high-temperature sintering. As a result of earnest research on measures to improve the joint strength of the joint in the cutting tool joined via the joining member,
One WC-based cemented carbide member and the other WC-based cemented carbide member are joined together via a joining member in which an Sm thin film is deposited on the surface of the Ti foil, and one WC-based cemented carbide member and the other WC-based cemented carbide member are joined. In the composite member in which the cemented carbide member is joined by the joint, the interface between the WC-based cemented carbide member and the joint is directed to the inside of the WC-based cemented carbide and in the bonded phase of the WC-based cemented carbide. An Sm diffusion layer having a predetermined average layer thickness in which Sm is diffused is formed, and the Co—Sm layer, TiC is formed from the interface between the WC-based cemented carbide member and the joint toward the center in the thickness direction of the joint. It was found that a composite member with improved high-temperature bonding strength between the WC-based cemented carbide member and the bonding portion can be obtained by providing the bonding portion in which the layer and the Ti—Co layer are formed.

そして、切削工具用の材料として、前記複合部材を用いた場合には、切れ刃に高負荷が作用し、かつ、高熱発生を伴う鋼や鋳鉄の重切削加工に供した場合であっても、接合部からの破断が発生することもなく、長期の使用に亘って、すぐれた切削性能を発揮することができることを見出したのである。 And as a material for a cutting tool, when using the composite member, even when a high load acts on the cutting edge, and when subjected to heavy cutting of steel or cast iron with high heat generation, The present inventors have found that excellent cutting performance can be exhibited over a long period of use without causing breakage from the joint.

本発明は、前記知見に基づいてなされたものであって、
「（１）ＷＣ基超硬合金部材同士が１〜５０μｍの平均層厚を有する接合部を介して接合されている複合部材であって、
前記ＷＣ基超硬合金部材と接合部との界面から、前記ＷＣ基超硬合金部材の内部に向かって、前記ＷＣ基超硬合金の結合相の平均組成がＣｏ８０原子％未満でＳｍ２０原子％以上となる平均層厚５〜１００μｍのＳｍ拡散層が形成されていることを特徴とする複合部材。
（２）前記接合部におけるＴｉの平均組成は５０〜９９原子％であることを特徴とする（１）に記載の複合部材。
（３）前記ＷＣ基超硬合金部材と接合部との界面から接合部の厚さ方向中心側に向かって、平均層厚０．１〜３μｍのＣｏ−Ｓｍ層、平均層厚０．５〜５μｍのＴｉＣ層、および、Ｔｉ−Ｃｏ層が形成されていることを特徴とする（１）または（２）に記載の複合部材。
（４）前記Ｃｏ−Ｓｍ層は、平均組成で２０〜８０原子％のＣｏと２０〜８０原子％のＳｍを含有し、前記ＴｉＣ層は、平均組成で９０原子％以上のＴｉＣを含有し、前記Ｔｉ−Ｃｏ合金層は、平均組成で４５〜７５原子％のＴｉと２５〜５５原子％のＣｏを含有することを特徴とする（３）に記載の複合部材。
（５）前記（１）乃至（４）のいずれかに記載の複合部材から構成されていることを特徴とする切削工具。」
を特徴とするものである。 The present invention has been made based on the above findings,
“(1) A composite member in which WC-based cemented carbide members are joined via joints having an average layer thickness of 1 to 50 μm,
From the interface between the WC-based cemented carbide member and the joint, toward the inside of the WC-based cemented carbide member, the average composition of the binder phase of the WC-based cemented carbide is less than 80 atomic percent of Co and 20 atomic percent or more of Sm. An Sm diffusion layer having an average layer thickness of 5 to 100 μm is formed.
(2) The composite member according to (1), wherein an average composition of Ti in the joint is 50 to 99 atomic%.
(3) From the interface between the WC-based cemented carbide member and the joint, toward the center in the thickness direction of the joint, a Co—Sm layer having an average layer thickness of 0.1 to 3 μm, an average layer thickness of 0.5 to The composite member according to (1) or (2), wherein a 5 μm TiC layer and a Ti—Co layer are formed.
(4) The Co—Sm layer contains 20-80 atomic% Co and 20-80 atomic% Sm in average composition, and the TiC layer contains 90 atomic% or more TiC in average composition, The composite member according to (3), wherein the Ti—Co alloy layer contains 45 to 75 atomic% Ti and 25 to 55 atomic% Co in average composition.
(5) A cutting tool comprising the composite member according to any one of (1) to (4). "
It is characterized by.

以下に、本発明について、詳細に説明する。   The present invention is described in detail below.

図１に示すように、本発明の複合部材は、一方のＷＣ基超硬合金部材と他方のＷＣ基超硬合金部材との間に接合部材を配置し（図１（ａ）参照）、接合部材を介して一方のＷＣ基超硬合金部材と他方のＷＣ基超硬合金部材とを突き合わせ、所定の加圧力を付加した状態で、所定の温度、時間をかけて、ＷＣ基超硬合金部材と接合部材とを固液相拡散接合する（図１（ｂ）参照）ことにより、ＷＣ基超硬合金部材同士が接合部を介して接合された本発明の複合部材を作製することができる。   As shown in FIG. 1, in the composite member of the present invention, a joining member is disposed between one WC-based cemented carbide member and the other WC-based cemented carbide member (see FIG. 1 (a)). One WC-based cemented carbide member and the other WC-based cemented carbide member are abutted with each other through the member, and a predetermined temperature and time are applied in a state where a predetermined pressure is applied, and a WC-based cemented carbide member is taken. And the joining member are solid-liquid phase diffusion joined (see FIG. 1 (b)), the composite member of the present invention in which the WC-based cemented carbide members are joined via the joining portion can be produced.

図２は、図１（ｂ）の拡大模式図を示す。
図２において、接合されるＷＣ基超硬合金部材と接合部との界面から、ＷＣ基超硬合金部材の内部に向かって、平均層厚５〜１００μｍのＳｍ拡散層が形成されており、該拡散層においては、ＷＣ基超硬合金の結合相の平均組成はＣｏ８０原子％未満でＳｍ２０原子％以上となる。
また、前記ＷＣ基超硬合金部材と接合部との界面から接合部の厚さ方向中心側に向かって、接合部には、Ｃｏ−Ｓｍ層、ＴｉＣ層およびＴｉ−Ｃｏ層が形成されている。 FIG. 2 shows an enlarged schematic diagram of FIG.
In FIG. 2, an Sm diffusion layer having an average layer thickness of 5 to 100 μm is formed from the interface between the WC-based cemented carbide member to be joined and the joint to the inside of the WC-based cemented carbide member. In the diffusion layer, the average composition of the binder phase of the WC-based cemented carbide is less than 80 atomic percent of Co and 20 atomic percent or more of Sm.
In addition, a Co—Sm layer, a TiC layer, and a Ti—Co layer are formed at the joint from the interface between the WC-based cemented carbide member and the joint toward the center in the thickness direction of the joint. .

前記ＷＣ基超硬合金部材と接合部との界面から、ＷＣ基超硬合金部材の内部に向かって形成されるＳｍ拡散層は、Ｔｉ箔表面にＳｍ蒸着膜を形成した接合部材を用いて固液相拡散接合を行った際、接合部材表面のＳｍ成分が、ＷＣ基超硬合金の結合相成分であるＣｏと共晶反応を起こし、ＷＣ基超硬合金部材と接合部との界面で溶融するとともに、ＷＣ基超硬合金部材と接合部との界面からその内部に向けてＳｍが拡散したことによって形成される拡散層である。
また、固液相拡散接合時のＳｍの溶融によって、ＷＣ基超硬合金部材と接合部との界面での濡れ性を確保され、強固な接合が行われる。
さらに、ＳｍはＷＣ基超硬合金部材中に拡散し、結合相成分であるＣｏと合金化して等温凝固するため、高融点層が残存し、接合温度（６００〜９００℃）以上の温度環境で使用しても接合部が溶融・軟化することはないので、高い高温接合強度を確保することができる。
固液相拡散接合を生じ得るに十分な温度、時間、圧力を与えた場合には、該拡散層におけるＷＣ基超硬合金の結合相成分であるＣｏにＳｍが拡散し、結合相の平均組成は、Ｃｏ８０原子％（以下、「原子％」を単に、「％」で示す。）未満でかつＳｍ２０％以上となり、拡散層の平均層厚は５〜１００μｍとなる。
なお、拡散層における好ましい結合相の平均組成は、Ｃｏ５０〜７０％でかつＳｍ
３０〜５０％の範囲内であり、また、拡散層の好ましい平均層厚は、２０〜５０μｍである。
上記拡散層における結合相の平均組成が、Ｃｏ８０原子％以上、Ｓｍ２０％未満の場合、あるいは、拡散層の平均層厚が５μｍ未満である場合には、ＷＣ基超硬合金部材と接合部材との十分な接合が行われていないため、複合部材の接合部における高温接合強度が満足できるものとはならない。
また、拡散層の平均層厚が１００μｍを超えるような場合には、接合部との界面近傍のＷＣ基超硬合金部材におけるＳｍ含有量が過剰となり、低融点化するため、高温使用条件下での使用、あるいは、高負荷条件下での使用において、接合強度が低下し、破損する恐れがある。 The Sm diffusion layer formed from the interface between the WC-based cemented carbide member and the joint to the inside of the WC-based cemented carbide member is solidified using a joining member in which an Sm vapor deposition film is formed on the Ti foil surface. When liquid phase diffusion bonding is performed, the Sm component on the surface of the joining member causes a eutectic reaction with Co, which is a binding phase component of the WC-based cemented carbide, and melts at the interface between the WC-based cemented carbide member and the joint. And a diffusion layer formed by Sm diffusing from the interface between the WC-based cemented carbide member and the joint to the inside thereof.
In addition, the melting of Sm during the solid-liquid phase diffusion bonding ensures wettability at the interface between the WC-based cemented carbide member and the bonded portion, and strong bonding is performed.
Further, Sm diffuses into the WC-based cemented carbide member, and is alloyed with Co, which is a binder phase component, so that it is isothermally solidified. Therefore, a high melting point layer remains, and in a temperature environment higher than the joining temperature (600 to 900 ° C.). Even if it is used, the bonded portion does not melt or soften, so that high high-temperature bonding strength can be ensured.
When sufficient temperature, time, and pressure are applied to cause solid-liquid phase diffusion bonding, Sm diffuses into Co, which is a binder phase component of the WC-based cemented carbide in the diffusion layer, and the average composition of the binder phase. Is less than 80 atomic% Co (hereinafter, “atomic%” is simply indicated by “%”) and Sm is 20% or more, and the average thickness of the diffusion layer is 5 to 100 μm.
The average composition of the binder phase in the diffusion layer is Co50 to 70% and Sm
It is in the range of 30 to 50%, and the preferable average layer thickness of the diffusion layer is 20 to 50 μm.
When the average composition of the binder phase in the diffusion layer is 80 atomic% or more of Co and less than 20% of Sm, or when the average layer thickness of the diffusion layer is less than 5 μm, the WC-based cemented carbide member and the bonding member Since sufficient joining is not performed, the high-temperature joining strength at the joint part of the composite member is not satisfactory.
In addition, when the average layer thickness of the diffusion layer exceeds 100 μm, the Sm content in the WC-based cemented carbide member in the vicinity of the interface with the joint becomes excessive and the melting point is lowered. In use or under high load conditions, joint strength may be reduced and may be damaged.

前記拡散層の平均層厚は、例えば、次のような方法によって求めることができる。
走査型電子顕微鏡およびオージェ電子分光装置を用いて、ＷＣ基超硬合金部材と接合部との界面を縦断面観察し、ＷＣ基超硬合金部材側からみて、ＷＣ結晶粒が観察される臨界位置をＷＣ基超硬合金部材と接合部との界面と定める。
前記界面からＷＣ基超硬合金の内部側へ、界面に垂直な方向５００μｍにわたって、１０μｍ間隔で５０本の線分を引く。
該線分について、線分析を行ってＷＣ基超硬合金の結合相中のＣｏ含有量およびＳｍ含有量を測定し、結合相中にＳｍを２０％以上含有する測定点のうち、界面からＷＣ基超硬合金の内部側に最も離れた測定点までの距離を各線分における拡散領域幅とする。
５０本の線分についての線分析のうちで、前記拡散領域幅の広いもの１０本の拡散領域幅を平均し、この値を拡散層の平均層厚として求める。 The average layer thickness of the diffusion layer can be determined, for example, by the following method.
Using a scanning electron microscope and an Auger electron spectrometer, the longitudinal section of the interface between the WC-based cemented carbide member and the joint is observed, and the critical position where the WC crystal grains are observed when viewed from the WC-based cemented carbide member side. Is defined as the interface between the WC-based cemented carbide member and the joint.
Fifty line segments are drawn at 10 μm intervals from the interface to the inner side of the WC-based cemented carbide over a direction of 500 μm perpendicular to the interface.
The line segment is subjected to line analysis to measure the Co content and the Sm content in the binder phase of the WC-based cemented carbide, and from the measurement points containing 20% or more of Sm in the binder phase, the WC is measured from the interface. The distance to the measurement point furthest away from the inner side of the base cemented carbide is defined as the diffusion region width in each line segment.
Of the line analysis of 50 line segments, the ten diffusion region widths having the wide diffusion region width are averaged, and this value is obtained as the average layer thickness of the diffusion layers.

また、前記拡散層の平均組成は、例えば、次のような方法によって求めることができる。
走査型電子顕微鏡を用いて、ＷＣ基超硬合金部材と接合部との界面を縦断面観察し、接合界面に平行な３本の線分を、拡散層を厚さ方向に４等分するように引き、オージェ電子分光装置を用いて、各直線状に存在する３点の結合相上で点測定を行い、測定点９点の測定値を平均することによって、拡散層におけるＣｏ、Ｓｍの平均組成を求める。 Moreover, the average composition of the said diffused layer can be calculated | required by the following methods, for example.
Using a scanning electron microscope, observe the longitudinal section of the interface between the WC-based cemented carbide member and the joint, and divide the three parallel lines parallel to the joint interface into four equal parts in the thickness direction. Then, using the Auger electron spectrometer, the point measurement is performed on the three bonded phases existing in each linear form, and the average value of Co and Sm in the diffusion layer is obtained by averaging the measurement values at the nine measurement points. Determine the composition.

固液相拡散接合時に、接合部には、ＷＣ基超硬合金部材と接合部との界面から接合部の厚さ方向中心側に向けて、Ｃｏ−Ｓｍ層、ＴｉＣ層およびＴｉ−Ｃｏ層が形成されるが、接合部全体としては、Ｔｉの平均含有量が５０〜９９％であることが好ましい。
接合部全体としてのＴｉの平均含有量が５０％未満では、接合部自体の強度が低下し、複合部材に高負荷が作用した場合には、接合部自体から破断・破損する恐れがあり、一方、Ｔｉの平均含有量が９９％を超えると、固液相拡散接合におけるＳｍの拡散が十分でないため、ＷＣ基超硬合金部材と接合部の接合強度が十分でなく、接合界面から破断することがあるという理由による。 At the time of solid-liquid phase diffusion bonding, a Co—Sm layer, a TiC layer, and a Ti—Co layer are formed in the joint from the interface between the WC-based cemented carbide member and the joint toward the center in the thickness direction of the joint. Although formed, as a whole joint part, it is preferable that the average content of Ti is 50 to 99%.
If the average content of Ti as the whole joint is less than 50%, the strength of the joint itself decreases, and when a high load is applied to the composite member, the joint itself may break or break. If the average content of Ti exceeds 99%, the diffusion of Sm in the solid-liquid phase diffusion bonding is not sufficient, so that the bonding strength between the WC-based cemented carbide member and the bonded portion is not sufficient, and the bonding interface breaks. Because there is.

固液相拡散接合時に形成される前記Ｃｏ−Ｓｍ層は、平均層厚０．１〜３μｍであって、その組成は、２０〜８０％のＣｏと２０〜８０％のＳｍからなることが好ましい。
このＣｏ−Ｓｍ層は、固液相拡散接合時、溶融したＳｍとのＣｏの共晶化反応によって形成されるものであるが、その平均層厚が０．１μｍ未満の場合、あるいは、Ｃｏ含有量が２０％未満であってＳｍ含有量が８０％を超えるような場合には、ＷＣ基超硬合金の内部へのＳｍの拡散が不十分であって、所定の平均層厚の拡散層が形成されないため、ＷＣ基超硬合金部材と接合部の界面接合強度が十分でない。
一方、Ｃｏ−Ｓｍ層の平均層厚が３μｍを超えるような場合、あるいは、Ｃｏ含有量が８０％を超えＳｍ含有量が２０％未満となる場合には、拡散層近傍のＣｏ量が減少し、その結果、ＷＣ基超硬合金自体の靱性が低下するため、高負荷が作用した際に、ＷＣ基超硬合金部材と接合部との界面近傍で破断を起こしやすくなる。
したがって、Ｃｏ−Ｓｍ層の平均層厚は０．１〜３μｍ、また、Ｃｏ−Ｓｍ層の組成は、２０〜８０％Ｃｏ−２０〜８０％Ｓｍとすることが好ましい。
なお、前記Ｃｏ−Ｓｍ層の平均層厚、組成は、複合部材作成時の固液相拡散接合条件によって制御されるが、後記するＴｉＣ層の平均層厚、組成、また、Ｔｉ−Ｃｏ層の組成についても、固液相拡散接合条件によって制御されることになる。 The Co—Sm layer formed at the time of solid-liquid phase diffusion bonding has an average layer thickness of 0.1 to 3 μm, and its composition is preferably composed of 20 to 80% Co and 20 to 80% Sm. .
This Co-Sm layer is formed by the eutectic reaction of Co with molten Sm at the time of solid-liquid phase diffusion bonding. When the average layer thickness is less than 0.1 μm, or Co-containing When the amount is less than 20% and the Sm content exceeds 80%, the diffusion of Sm into the WC-based cemented carbide is insufficient, and a diffusion layer having a predetermined average layer thickness is formed. Since it is not formed, the interfacial bonding strength between the WC-based cemented carbide member and the joint is not sufficient.
On the other hand, when the average thickness of the Co—Sm layer exceeds 3 μm, or when the Co content exceeds 80% and the Sm content is less than 20%, the Co content near the diffusion layer decreases. As a result, the toughness of the WC-based cemented carbide itself is reduced, and therefore, when a high load is applied, the WC-based cemented carbide alloy tends to break near the interface between the WC-based cemented carbide member and the joint.
Therefore, the average layer thickness of the Co—Sm layer is preferably 0.1 to 3 μm, and the composition of the Co—Sm layer is preferably 20 to 80% Co-20 to 80% Sm.
The average layer thickness and composition of the Co—Sm layer are controlled by the solid-liquid phase diffusion bonding conditions at the time of preparing the composite member, but the average layer thickness and composition of the TiC layer described later, and the Ti—Co layer The composition is also controlled by the solid-liquid phase diffusion bonding conditions.

前記ＴｉＣ層は、接合部材として用いたＴｉ箔のＴｉ成分と、ＷＣ基超硬合金の構成成分であるＣが、固液相拡散接合時の反応で形成されたものであるが、前記所定の平均層厚及び組成の拡散層、また、前記所定平均層厚及び組成のＣｏ―Ｓｍ層を形成させたときに、平均層厚０．５〜５μｍの層として必然的に形成される層である。
ＴｉＣ層の主要成分は、ＴｉＣであって、９０％以上のＴｉＣが含有されているが、ＴｉＣ以外の成分（例えば、Ｗ成分、Ｃｏ成分、Ｓｍ成分）が微量含有されていても、ＴｉＣ層の高温強度に大きな悪影響を及ぼさないことから、Ｗ成分、Ｃｏ成分、Ｓｍ成分等の微量成分については、合計含有量で１０％未満の含有が許容される。 The TiC layer is formed by the reaction of the Ti component of the Ti foil used as the joining member and the constituent component of the WC-based cemented carbide alloy during solid-liquid diffusion bonding. A diffusion layer having an average layer thickness and composition, and a layer that is inevitably formed as a layer having an average layer thickness of 0.5 to 5 μm when the Co—Sm layer having the predetermined average layer thickness and composition is formed. .
The main component of the TiC layer is TiC, and 90% or more of TiC is contained. Even if a small amount of components other than TiC (for example, W component, Co component, Sm component) is contained, the TiC layer Since there is no significant adverse effect on the high-temperature strength, the total content of less than 10% is acceptable for trace components such as the W component, Co component, and Sm component.

前記Ｔｉ−Ｃｏ層は、固液相拡散接合時にＷＣ基超硬合金から拡散してきたＣｏと、接合部材として用いたＴｉ箔のＴｉ成分が反応して形成される層であるが、その組成は、Ｔｉが４５〜７５％、また、Ｃｏが２５〜５５％であることが好ましい。
前記Ｔｉ−Ｃｏ合金層において、Ｔｉが４５％未満でＣｏが５５％を超えると、ＷＣ基超硬合金からのＣｏ拡散量が多すぎるため、ＷＣ基超硬合金自体の強度が低下しやすくなり、一方、Ｔｉが７５％を超えＣｏが２５％未満になると、接合部を介したＷＣ基超硬合金同士の強固な接合状態を維持できなくなる。
したがって、接合部に形成されるＴｉ−Ｃｏ層におけるＴｉ含有量は４５〜７５％、また、Ｃｏ含有量は２５〜５５％とすることが好ましい。 The Ti—Co layer is a layer formed by the reaction of Co diffused from the WC-based cemented carbide during solid-liquid phase diffusion bonding with the Ti component of the Ti foil used as the bonding member. Ti is preferably 45 to 75%, and Co is preferably 25 to 55%.
In the Ti-Co alloy layer, when Ti is less than 45% and Co is more than 55%, the amount of Co diffusion from the WC-based cemented carbide is too large, and the strength of the WC-based cemented carbide itself tends to decrease. On the other hand, when Ti exceeds 75% and Co becomes less than 25%, it becomes impossible to maintain a strong bonded state between the WC-based cemented carbides via the bonded portion.
Therefore, the Ti content in the Ti—Co layer formed in the joint is preferably 45 to 75%, and the Co content is preferably 25 to 55%.

前記Ｃｏ−Ｓｍ層、ＴｉＣ層およびＴｉ−Ｃｏ層の平均層厚、組成は、次のようにして求めることができる。
ＷＣ基超硬合金部材と接合部との界面から、接合部側に界面に垂直な方向５０μｍにかけて、面状の元素分析を行い、接合部中でＣｏおよびＳｍを含有する層をＣｏ−Ｓｍ層とし、ＴｉおよびＣを含有する層をＴｉＣ層とし、ＴｉとＣｏを含有する層をＴｉ−Ｃｏ層として、各層の平均層厚および各層における各成分の含有量を測定し、各測定値を平均することによって、各層の平均層厚、平均組成を求めた。
なお、ＴｉおよびＣを含有するとともに、Ｗ、ＳｍおよびＴｉの測定された合計含有量が１０％未満である層はＴｉＣ層とした。 The average layer thickness and composition of the Co—Sm layer, TiC layer and Ti—Co layer can be determined as follows.
A planar elemental analysis is performed from the interface between the WC-based cemented carbide member and the bonded portion to the bonded portion side in a direction perpendicular to the bonded surface of 50 μm, and a layer containing Co and Sm in the bonded portion is a Co—Sm layer. The layer containing Ti and C is the TiC layer, the layer containing Ti and Co is the Ti-Co layer, the average layer thickness of each layer and the content of each component in each layer are measured, and each measured value is averaged By doing this, the average layer thickness and average composition of each layer were determined.
A layer containing Ti and C and having a measured total content of W, Sm and Ti of less than 10% was a TiC layer.

本発明では、特定構造、材質の接合部材を用い、固液相拡散接合を施すことにより、前記本発明の複合部材を得ることができる。
本発明で使用する接合部材としては、前述したように、Ｓｍ蒸着膜−Ｔｉ箔−Ｓｍ蒸着膜の積層体からなる平均層厚１〜５０μｍの接合部材を用いることができ、Ｓｍ蒸着膜の厚さは、０．１〜５μｍとすることが好ましい。 In the present invention, the composite member of the present invention can be obtained by performing solid-liquid phase diffusion bonding using a bonding member having a specific structure and material.
As described above, as the bonding member used in the present invention, a bonding member having an average layer thickness of 1 to 50 μm made of a laminate of Sm vapor deposition film-Ti foil-Sm vapor deposition film can be used. The thickness is preferably 0.1 to 5 μm.

本発明の複合部材は、例えば、以下の方法により、作製することができる。
前記の接合部材を、一方のＷＣ基超硬合金部材と他方のＷＣ基超硬合金部材との間に介在させ、例えば、１×１０^−３Ｐａ以下の真空中、６００〜９００℃の範囲内の所定温度に５〜６００分間保持し、荷重０．５〜１０ＭＰａの条件で加圧し、固液相拡散接合することによって、ＷＣ基超硬合金部材中に拡散層が形成され、また、接合部材中には、Ｃｏ−Ｓｍ層、ＴｉＣ層およびＴｉ−Ｃｏ層が形成されている接合部を有する複合部材を作製することができる。
特に、固液相拡散接合時において、接合部材表面のＳｍ成分が溶融して、ＷＣ基超硬合金部材と接合部との界面での濡れ性を確保して高温接合強度を高めるとともに、ＷＣ基超硬合金の結合相であるＣｏと合金化して等温凝固する際、高融点層が残存するため高温接合強度を高めるため、すぐれた高温接合強度を備えた複合材料が形成される。 The composite member of the present invention can be produced, for example, by the following method.
The joining member is interposed between one WC-based cemented carbide member and the other WC-based cemented carbide member. For example, in a vacuum of 1 × 10 ⁻³ Pa or less, within a range of 600 to 900 ° C. The diffusion layer is formed in the WC-based cemented carbide member by holding at a predetermined temperature of 5 to 600 minutes, pressurizing under a load of 0.5 to 10 MPa, and performing solid-liquid phase diffusion bonding, and the bonding member Among them, a composite member having a joint portion in which a Co—Sm layer, a TiC layer, and a Ti—Co layer are formed can be manufactured.
In particular, at the time of solid-liquid phase diffusion bonding, the Sm component on the surface of the bonding member is melted to ensure wettability at the interface between the WC-based cemented carbide member and the bonding portion, thereby increasing the high-temperature bonding strength, and When alloying with Co, which is a cemented phase of cemented carbide, and isothermally solidifying, a high melting point layer remains, so that the high temperature bonding strength is increased, so that a composite material having excellent high temperature bonding strength is formed.

前記の固液相拡散接合により作製した本発明の複合部材は、一方のＷＣ基超硬合金部材を切刃部側とし、他方のＷＣ基超硬合金部材を工具基体とすることにより切削工具を構成することができる。
より具体的にいえば、例えば、複合部材の一方のＷＣ基超硬合金部材を、切刃部側であるｃＢＮ焼結体の裏打ち材とし、また、他方のＷＣ基超硬合金部材を工具基体（台金）とすることにより、ｃＢＮ切削工具を形成することができる。 The composite member of the present invention produced by the above-mentioned solid-liquid phase diffusion bonding has a cutting tool by using one WC-based cemented carbide member as a cutting edge portion side and the other WC-based cemented carbide member as a tool base. Can be configured.
More specifically, for example, one WC-based cemented carbide member of the composite member is used as a backing material for a cBN sintered body on the cutting edge side, and the other WC-based cemented carbide member is used as a tool base. By using (base metal), a cBN cutting tool can be formed.

本発明は、ＷＣ基超硬合金部材同士を、Ｔｉ箔の表面にＳｍ蒸着膜が形成された積層体からなる接合部材を介して固液相拡散接合することによって、ＷＣ基超硬合金部材と接合部との界面からＷＣ基超硬合金部材の内部にかけてＳｍ拡散層を形成し、かつ、接合部には、接合部の厚さ方向中心に向かってＣｏ−Ｓｍ層、ＴｉＣ層およびＴｉ−Ｃｏ層を形成することによって、高温接合強度に優れた複合部材を得ることができるのである。
また、上記複合部材から切削工具を構成した場合には、切刃に高負荷が作用する重切削加工に供した場合であっても、接合部からの破断を生じることはなく、長期の使用に亘って、すぐれた切削性能を発揮するのである。 The present invention provides a WC-based cemented carbide member and a WC-based cemented carbide member by joining the WC-based cemented carbide members to each other through a solid-liquid phase diffusion bonding through a joining member made of a laminate in which an Sm vapor deposition film is formed on the surface of a Ti foil. An Sm diffusion layer is formed from the interface with the joint to the inside of the WC-based cemented carbide member, and the Co—Sm layer, TiC layer, and Ti—Co are formed in the joint toward the center in the thickness direction of the joint. By forming the layer, a composite member excellent in high-temperature bonding strength can be obtained.
In addition, when a cutting tool is constructed from the above composite member, even if it is subjected to heavy cutting where a high load acts on the cutting blade, it will not break from the joint, and it can be used for a long time. It exhibits excellent cutting performance.

本発明の複合部材の作製過程を示した模式図であって、（ａ）は、接合前、（ｂ）は固相拡散接合によって得られた接合後の複合部材を示す。It is the schematic diagram which showed the preparation process of the composite member of this invention, Comprising: (a) is before joining, (b) shows the composite member after joining obtained by solid phase diffusion joining. 図１（ｂ）の拡大模式図であり、本発明の複合部材の接合部近傍の拡大模式図を示す。It is an expansion schematic diagram of Drawing 1 (b), and shows the expansion schematic diagram near the joined part of the composite member of the present invention. （ａ）は、本発明の複合部材の接合部近傍の断面ＳＥＭ像を示し、（ｂ）は、（ａ）の部分拡大図を示す。(A) shows the cross-sectional SEM image of the junction part vicinity of the composite member of this invention, (b) shows the elements on larger scale of (a).

つぎに、本発明を実施例に基づき具体的に説明する。
なお、以下に説明した実施例は、本発明の一実施態様であって、本発明の具体的な実施の形態は、これに制限されるものではない。 Next, the present invention will be specifically described based on examples.
In addition, the Example demonstrated below is one embodiment of this invention, Comprising: Specific embodiment of this invention is not restrict | limited to this.

原料粉末として、いずれも０．５〜１μｍの平均粒径を有するＷＣ粉末、ＶＣ粉末、ＴａＣ粉末、ＮｂＣ粉末、Ｃｒ_３Ｃ_２粉末およびＣｏ粉末を用意し、これら原料粉末を、表１に示される配合組成に配合し、ボールミルで２４時間湿式混合し、乾燥した後、１００ＭＰａの圧力で圧粉体にプレス成形し、この圧粉体を６Ｐａの真空中、温度１４００℃、保持時間１時間の条件で焼結し、表１に示される４種のＷＣ基超硬合金焼結体（以下、単に「超硬合金」という）Ａ−１〜Ａ−４を形成した。 As raw material powders, WC powder, VC powder, TaC powder, NbC powder, Cr ₃ C ₂ powder and Co powder all having an average particle diameter of 0.5 to 1 μm were prepared. These raw material powders are shown in Table 1. It is blended into the blended composition, wet mixed in a ball mill for 24 hours, dried, and then pressed into a green compact at a pressure of 100 MPa, and this green compact is vacuumed at 6 Pa, temperature 1400 ° C., holding time 1 hour. Sintering was performed under the conditions to form four types of WC-based cemented carbide sintered bodies (hereinafter simply referred to as “superhard alloys”) A-1 to A-4 shown in Table 1.

次に、ｃＢＮ焼結体の原料粉末として、いずれも０．５〜４μｍの範囲内の平均粒径を有するｃＢＮ粉末、ＴｉＮ粉末、ＴｉＣＮ粉末、ＴｉＢ_２粉末、ＴｉＣ粉末、ＡｌＮ粉末、Ａｌ_２Ｏ_３粉末を用意し、これら原料粉末を所定の配合組成で配合し、ボールミルで２４時間アセトンを用いて湿式混合し、乾燥した後、１００ＭＰａの圧力で直径１５ｍｍ×厚さ１ｍｍの寸法をもった圧粉体にプレス成形した。
ついで、前記超硬合金Ａ−１〜Ａ−４を、直径１５ｍｍ×厚さ２ｍｍのサイズの焼結体とし、これを、ｃＢＮ焼結体の焼結時の裏打ち材とし、裏打ち材上に前記ｃＢＮ圧粉体を表２に示す組合せで積層し、ついでこの積層体を、超高圧発生装置を用いて、温度：１３００℃、圧力：５．５ＧＰａ、時間：３０分の条件で焼結し、複合焼結体Ｂ−１〜Ｂ−４を作製した。
複合焼結体Ｂ−１〜Ｂ−４のｃＢＮ焼結体の組成について、ｃＢＮ焼結体断面研磨面のＳＥＭ観察結果の画像分析によりｃＢＮの面積％を容量％として求めた。
ｃＢＮ以外の成分については、主結合相およびその他の結合相を構成している成分を確認するに止めた。その結果を表２に示す。 Next, cBN powder, TiN powder, TiCN powder, TiB ₂ powder, TiC powder, AlN powder, Al ₂ O each having an average particle size in the range of 0.5 to 4 μm as the raw material powder of the cBN sintered body ₃ powders were prepared, these raw material powders were blended in a prescribed composition, wet mixed with acetone for 24 hours in a ball mill, dried, and then pressure having a size of 15 mm diameter × 1 mm thickness at 100 MPa pressure. Press-molded into powder.
Next, the cemented carbides A-1 to A-4 are made into a sintered body having a diameter of 15 mm and a thickness of 2 mm, and this is used as a backing material during sintering of the cBN sintered body, cBN compacts were laminated in the combinations shown in Table 2, and this laminate was then sintered using an ultrahigh pressure generator at a temperature of 1300 ° C., a pressure of 5.5 GPa, and a time of 30 minutes. Composite sintered bodies B-1 to B-4 were produced.
Regarding the composition of the cBN sintered bodies of the composite sintered bodies B-1 to B-4, the area% of cBN was determined as the volume% by image analysis of the SEM observation result of the cross-section polished surface of the cBN sintered body.
About components other than cBN, it stopped only to confirm the component which comprises the main binder phase and other binder phases. The results are shown in Table 2.

次に、本発明接合部材１〜４として、表３に示すＳｍ蒸着膜−Ｔｉ箔−Ｓｍ蒸着膜からなる積層体Ｃ−１〜Ｃ−４を用意した。
また、後記する比較例のために、比較例接合部材５〜７として、同じく表３に示すＳｍ蒸着膜−Ｔｉ箔−Ｓｍ蒸着膜からなる積層体Ｃ−５〜Ｃ−７も用意した。 Next, as the present invention bonding members 1 to 4, laminates C-1 to C-4 made of Sm vapor deposition film-Ti foil-Sm vapor deposition film shown in Table 3 were prepared.
In addition, for comparative examples to be described later, laminates C-5 to C-7 made of Sm vapor deposition film-Ti foil-Sm vapor deposition film similarly shown in Table 3 were also prepared as comparative example bonding members 5-7.

次いで、超硬合金Ａ−１〜Ａ−４と複合焼結体Ｂ−１〜Ｂ−４の間に、表３に示す本発明の接合部材１〜４を挿入介在させ、表４に示す条件（即ち、１×１０^−３Ｐａ以下の真空中、６００〜９００℃の範囲内の所定温度に５〜６００分間保持し、０．５〜１０ＭＰａの加圧力を付加した条件）で複合焼結体と超硬合金を加圧接合し、表６に示す拡散層を形成するとともに、同じく表６に示すＣｏ−Ｓｍ層、ＴｉＣ層及びＴｉ−Ｃｏ層を備えた接合部を有する本発明複合部材１〜１０を作製した。
なお、複合焼結体はｃＢＮ焼結体が外面、裏打ち材が内面となるように配置、即ち、裏打ち材であるＷＣ基超硬合金と工具基体（台金）であるＷＣ基超硬合金が接合部材を介し接合するように配置した。
また、今回の実施例においては、裏打ち材であるＷＣ基超硬合金と同じ組成のＷＣ基超硬合金を工具基体（台金）であるＷＣ基超硬合金として用いたが、本発明の範囲内になるように異なる組成のＷＣ基超硬合金を用い接合を行ってもよい。 Next, the joining members 1 to 4 of the present invention shown in Table 3 are interposed between the cemented carbides A-1 to A-4 and the composite sintered bodies B-1 to B-4, and the conditions shown in Table 4 (Ie, a condition in which a pressure of 0.5 to 10 MPa is applied at a predetermined temperature within a range of 600 to 900 ° C. for 5 to 600 minutes in a vacuum of 1 × 10 ⁻³ Pa or less) And the cemented carbide is pressure-bonded to form a diffusion layer shown in Table 6, and the composite member 1 of the present invention having a joint portion including a Co—Sm layer, a TiC layer, and a Ti—Co layer also shown in Table 6 To 10 were produced.
The composite sintered body is arranged so that the cBN sintered body is the outer surface and the backing material is the inner surface, that is, the WC-based cemented carbide that is the backing material and the WC-based cemented carbide that is the tool base (base metal). It arrange | positioned so that it may join via a joining member.
Further, in this example, a WC-based cemented carbide having the same composition as the WC-based cemented carbide as the backing material was used as the WC-based cemented carbide as the tool base (base metal). The joining may be performed using WC-based cemented carbides having different compositions so as to be inside.

比較のために、表３に示される接合部材を用い、これを、超硬合金Ａ−１〜Ａ−４と複合焼結体Ｂ−１〜Ｂ−４の間に介在装入し、表５に示す条件で、複合焼結体と超硬合金を加圧接合し、表７に示す拡散層、あるいは、表７に示す各層を備えた接合部を有する比較例複合部材１〜１０を作製した。
なお、複合焼結体の接合配置は本発明複合部材と同様とした。 For comparison, a joining member shown in Table 3 was used, and this was interposed between cemented carbides A-1 to A-4 and composite sintered bodies B-1 to B-4. The composite sintered body and the cemented carbide were pressure-bonded under the conditions shown in FIG. 6 to produce comparative example composite members 1 to 10 having a diffusion layer shown in Table 7 or a joint provided with each layer shown in Table 7. .
The joint arrangement of the composite sintered body was the same as that of the composite member of the present invention.

ついで、本発明複合部材１〜１０及び比較例複合部材１〜１０について、ＷＣ基超硬合金部材と接合部との界面から内部に向けて形成された拡散層、ＷＣ基超硬合金部材と接合部との界面から接合部の厚さ方向中心側に形成されたＣｏ−Ｓｍ層、ＴｉＣ層およびＴｉ−Ｃｏ層の平均層厚、成分組成を、走査型電子顕微鏡及びオージェ電子分光装置を用いて、次のように測定・算出した。   Next, with respect to the composite members 1 to 10 of the present invention and the comparative composite members 1 to 10, the diffusion layer formed from the interface between the WC-based cemented carbide member and the joint portion to the inside, the WC-based cemented carbide member and the joint The average layer thickness and component composition of the Co—Sm layer, TiC layer, and Ti—Co layer formed on the center side in the thickness direction of the joint from the interface with the part are measured using a scanning electron microscope and an Auger electron spectrometer. Measured and calculated as follows.

まず、ＷＣ基超硬合金部材と接合部との界面から内部に向けて形成された拡散層について、ＷＣ基超硬合金部材と接合部との界面を縦断面観察し、ＷＣ基超硬合金部材側からみて、ＷＣ結晶粒が観察される臨界位置をＷＣ基超硬合金部材と接合部との界面と定めた。
ついで、前記界面からＷＣ基超硬合金の内部側へ、界面に垂直な方向５００μｍにわたって、１０μｍ間隔で５０本の線分を引いた。
該線分について、線分析を行ってＷＣ基超硬合金の結合相中のＣｏ含有量およびＳｍ含有量を測定し、結合相中にＳｍを２０％以上含有する測定点のうち、界面からＷＣ基超硬合金の内部側に最も離れた測定点までの距離を各線分における拡散領域幅とした。
５０本の線分についての線分析のうちで、前記拡散領域幅の広いもの１０本の拡散領域幅を平均し、この値を拡散層の平均層厚として求めた。
また、前記拡散層の平均組成は、走査型電子顕微鏡を用いて、ＷＣ基超硬合金部材と接合部との界面を縦断面観察し、接合界面に平行な３本の線分を、拡散層を厚さ方向に４等分するように引き、オージェ電子分光装置を用いて、各直線状に存在する３点の結合相上で点測定を行い、測定点９点の測定値を平均することによって、拡散層におけるＣｏ、Ｓｍの平均組成を求めた。 First, with respect to the diffusion layer formed from the interface between the WC-based cemented carbide member and the joint to the inside, the longitudinal section of the interface between the WC-based cemented carbide member and the joint is observed, and the WC-based cemented carbide member When viewed from the side, the critical position where WC crystal grains are observed was defined as the interface between the WC-based cemented carbide member and the joint.
Next, 50 line segments were drawn at 10 μm intervals from the interface toward the inner side of the WC-based cemented carbide over a direction of 500 μm perpendicular to the interface.
The line segment is subjected to line analysis to measure the Co content and the Sm content in the binder phase of the WC-based cemented carbide, and from the measurement points containing 20% or more of Sm in the binder phase, the WC is measured from the interface. The distance to the most distant measurement point on the inner side of the base cemented carbide was defined as the diffusion region width in each line segment.
Among the line analysis of 50 line segments, the 10 diffusion region widths having the wide diffusion region width were averaged, and this value was obtained as the average layer thickness of the diffusion layers.
In addition, the average composition of the diffusion layer is obtained by observing a longitudinal section of the interface between the WC-based cemented carbide member and the joint using a scanning electron microscope, and obtaining three line segments parallel to the joint interface. Is divided into four equal parts in the thickness direction, and using an Auger electron spectrometer, point measurement is performed on the three bonded phases existing in each straight line, and the measurement values at nine measurement points are averaged. Thus, the average composition of Co and Sm in the diffusion layer was obtained.

また、前記Ｃｏ−Ｓｍ層、ＴｉＣ層およびＴｉ−Ｃｏ層の平均層厚、組成は、次のようにして求めた。
ＷＣ基超硬合金部材と接合部との界面から、接合部側に界面に垂直な方向５０μｍにかけて、１０本の線分を引き、同線分上で元素分析を行い、接合部中でＣｏおよびＳｍを含有する層をＣｏ−Ｓｍ層とし、ＴｉおよびＣを含有する層をＴｉＣ層とし、ＴｉとＣｏを含有する層をＴｉ−Ｃｏ層として、各層の平均層厚を測定した。また、各層における厚さ方向の中央点における各成分の含有量を測定した。これら１０本の線分上の各測定値を平均することによって、各層の平均層厚、平均組成を求めた。
なお、ＴｉおよびＣを含有するとともに、Ｗ、ＳｍおよびＴｉの測定された合計含有量が１０％未満である層はＴｉＣ層として扱った。
表６、表７に、その結果を示す。 The average layer thickness and composition of the Co—Sm layer, TiC layer and Ti—Co layer were determined as follows.
Ten line segments are drawn from the interface between the WC-based cemented carbide member and the joint to the joint side in a direction perpendicular to the interface of 50 μm, and elemental analysis is performed on the line segment. A layer containing Sm was a Co—Sm layer, a layer containing Ti and C was a TiC layer, and a layer containing Ti and Co was a Ti—Co layer, and the average layer thickness of each layer was measured. Further, the content of each component at the center point in the thickness direction in each layer was measured. By averaging each measured value on these ten line segments, the average layer thickness and average composition of each layer were determined.
A layer containing Ti and C and having a measured total content of W, Sm and Ti of less than 10% was treated as a TiC layer.
Tables 6 and 7 show the results.

次に、本発明複合部材１〜１０及び比較例複合部材１〜１０から切削工具を作製し、切削加工における破断発生の有無を調査し、これによって本発明複合部材１〜１０の特性を評価した。
まず、複合部材からなる切削工具は、以下のように作製した。
前記で作製した複合焼結体Ｂ−１〜Ｂ−４を、平面形状：開き角８０°の一辺が４ｍｍの二等辺三角形×厚さ：２ｍｍの寸法に切断した。続いて、前記超硬合金Ａ−１〜Ａ−４を、平面形状：１２．７ｍｍの内接円で開き角８０°の菱形×厚さ：４．７６ｍｍの寸法の焼結体とし、この焼結体の上下平行面の内、何れかの面の１角を、研削盤を用いて上記複合焼結体の形状に対応した大きさの切欠きを形成した。この切欠きの底面の面積は２．９６ｍｍ^２であり、側面の面積は４．８９ｍｍ^２である。次いで、超硬合金Ａ−１〜Ａ−４と複合焼結体Ｂ−１〜Ｂ−４の間に、表３に示される接合部材を挿入介在させ、表４に示す条件で複合焼結体とＷＣ基超硬合金を加圧接合し、この複合部材を外周研磨加工後、切刃部分にＲ：０．０７ｍｍのホーニング加工を施すことによりＩＳＯ規格・ＣＮＧＡ１２０４０８のインサート形状を有する、本発明切削工具１〜１０を作製した。
なお、複合焼結体はｃＢＮ焼結体が外面、裏打ち材が内面となるよう、即ち、裏打ち材と工具基体（台金）が接合部材を介し接合するように配置した。
また、これら本発明切削工具１〜１０の接合部は表６に示す本発明複合部材１〜１０と実質的に同様であることを確認した。
同様に、前記で作製した複合焼結体Ｂ−１〜Ｂ−４と、前記で作製した超硬合金Ａ−１〜Ａ−４の間に、表３に示す接合部材を挿入介在させ、表５に示す条件で加圧接合し、比較例切削工具１〜１０を作製した。
また、これら比較例切削工具１〜１０の接合部は表７に示す比較例複合部材１〜１０と実質的に同様であることを確認した。 Next, a cutting tool was produced from the composite members 1 to 10 of the present invention and the composite members 1 to 10 of the comparative example, and the presence or absence of occurrence of breakage in the cutting process was investigated, thereby evaluating the characteristics of the composite members 1 to 10 of the present invention. .
First, the cutting tool which consists of a composite member was produced as follows.
The composite sintered bodies B-1 to B-4 produced above were cut into a plane shape: an isosceles triangle with an opening angle of 80 ° having a side of 4 mm × thickness: 2 mm. Subsequently, the cemented carbides A-1 to A-4 are formed into a sintered body having a planar shape: an inscribed circle of 12.7 mm and an open angle of 80 ° × thickness: 4.76 mm. A notch having a size corresponding to the shape of the composite sintered body was formed in one corner of any one of the upper and lower parallel surfaces of the bonded body using a grinding machine. The area of the bottom surface of this notch is 2.96 mm ² and the area of the side surface is 4.89 mm ² . Subsequently, the joining members shown in Table 3 are inserted between the cemented carbides A-1 to A-4 and the composite sintered bodies B-1 to B-4, and the composite sintered body is subjected to the conditions shown in Table 4. And the WC base cemented carbide are pressure bonded, and after cutting the outer periphery of this composite member, the cutting edge portion is subjected to a honing process of R: 0.07 mm to have an ISO standard / CNGA120408 insert shape. Tools 1-10 were produced.
The composite sintered body was arranged so that the cBN sintered body was the outer surface and the backing material was the inner surface, that is, the backing material and the tool base (base metal) were joined via the joining member.
Moreover, it confirmed that the junction part of these invention cutting tools 1-10 was substantially the same as this invention composite member 1-10 shown in Table 6.
Similarly, the joining members shown in Table 3 are inserted between the composite sintered bodies B-1 to B-4 produced above and the cemented carbides A-1 to A-4 produced above, Pressure bonding was performed under the conditions shown in FIG.
Moreover, it confirmed that the junction part of these comparative example cutting tools 1-10 was substantially the same as the comparative example composite members 1-10 shown in Table 7.

つぎに、前記各種の切削工具をいずれも工具鋼製バイトの先端部に固定治具にてネジ止めした状態で、本発明切削工具１〜１０、比較例切削工具１〜１０について、以下に示す浸炭焼き入れ鋼の乾式高速重切削試験を行い、刃先脱落の有無および破断部の場所を観察した。
被削材：ＪＩＳ・ＳＣＭ４１５（硬さ：５８ＨＲｃ）の丸棒、
切削速度：２７０ ｍ／ｍｉｎ．、
切り込み：０．４ ｍｍ、
送り：０．３ ｍｍ／ｒｅｖ．、
切削時間：１３分、
（通常の切削速度、送りは、それぞれ、１５０ｍ／ｍｉｎ、０．２ｍｍ／ｒｅｖ．）
表８に、切削試験結果を示す。 Next, the cutting tools 1 to 10 and the comparative cutting tools 1 to 10 according to the present invention are shown below in the state in which the various cutting tools are all screwed to the tip of the tool steel tool with a fixing jig. A dry high-speed heavy cutting test of carburized and quenched steel was performed, and the presence or absence of the cutting edge and the location of the fracture portion were observed.
Work material: JIS / SCM415 (hardness: 58HRc) round bar,
Cutting speed: 270 m / min. ,
Cutting depth: 0.4 mm,
Feed: 0.3 mm / rev. ,
Cutting time: 13 minutes
(Normal cutting speed and feed are 150 m / min and 0.2 mm / rev., Respectively)
Table 8 shows the cutting test results.

表８に示されるように、本発明複合部材１〜１０から構成された本発明切削工具１〜１０は、刃先の脱落もなく、長期の使用に亘ってすぐれた切削性能を発揮することから、本発明複合部材の接合部は、すぐれた高温接合強度を有するといえる。
これに対して、比較例複合部材１〜１０から構成される比較例切削工具１〜１０は、切削中に接合部から刃先脱落が生じ、早期に工具寿命に至ることから、本発明複合部材に比して、接合部の高温接合強度が劣っていることは明らかである。 As shown in Table 8, the present invention cutting tools 1 to 10 composed of the present invention composite members 1 to 10 have no cutting edge and exhibit excellent cutting performance over a long period of use. It can be said that the joint part of the composite member of the present invention has excellent high-temperature joint strength.
On the other hand, the comparative cutting tools 1 to 10 composed of the comparative composite members 1 to 10 cause the cutting edge to fall off from the joint during cutting, resulting in early tool life. It is clear that the high-temperature bonding strength of the bonded portion is inferior.

なお、本実施例においては、切削工具としてインサートを例にとって説明したが、本発明は、インサートに限られることなく、ドリル、エンドミルなど切刃部と工具本体との接合部をもつすべての切削工具、ビット等の掘削工具に適用可能であることはいうまでもない。   In this embodiment, the insert has been described as an example of the cutting tool. However, the present invention is not limited to the insert, and all cutting tools having a joint between the cutting edge portion and the tool body, such as a drill and an end mill. Needless to say, the present invention is applicable to drilling tools such as bits.

本発明の複合部材は、その接合部の高温接合強度が大であり、この複合部材から作製した切削工具は、各種の鋼や鋳鉄などの高速重切削加工等の高負荷切削加工に使用することができ、しかも、長期に亘って安定した切削性能を発揮するものであるから、切削加工装置の高性能化、並びに切削加工の省力化および省エネ化、さらに低コスト化に十分満足に対応できるものである。   The composite member of the present invention has high joint strength at high temperatures, and cutting tools made from this composite member should be used for high-load cutting such as high-speed heavy cutting of various steels and cast iron. In addition, since it exhibits stable cutting performance over a long period of time, it can sufficiently satisfy the high performance of cutting equipment, labor saving and energy saving of cutting, and further cost reduction. It is.

Claims (5)

ＷＣ基超硬合金部材同士が１〜５０μｍの平均層厚を有する接合部を介して接合されている複合部材であって、
前記ＷＣ基超硬合金部材と接合部との界面から、前記ＷＣ基超硬合金部材の内部に向かって、前記ＷＣ基超硬合金の結合相の平均組成がＣｏ８０原子％未満でＳｍ２０原子％以上となる平均層厚５〜１００μｍのＳｍ拡散層が形成されていることを特徴とする複合部材。 A WC-based cemented carbide member is a composite member joined through joints having an average layer thickness of 1 to 50 μm,
From the interface between the WC-based cemented carbide member and the joint, toward the inside of the WC-based cemented carbide member, the average composition of the binder phase of the WC-based cemented carbide is less than 80 atomic percent of Co and 20 atomic percent or more of Sm. An Sm diffusion layer having an average layer thickness of 5 to 100 μm is formed. 前記接合部におけるＴｉの平均組成は５０〜９９原子％であることを特徴とする請求項１に記載の複合部材。 2. The composite member according to claim 1, wherein an average composition of Ti in the joint is 50 to 99 atomic%. 前記ＷＣ基超硬合金部材と接合部との界面から接合部の厚さ方向中心側に向かって、平均層厚０．１〜３μｍのＣｏ−Ｓｍ層、平均層厚０．５〜５μｍのＴｉＣ層、および、Ｔｉ−Ｃｏ層が形成されていることを特徴とする請求項１または２に記載の複合部材。 A Co—Sm layer having an average layer thickness of 0.1 to 3 μm and TiC having an average layer thickness of 0.5 to 5 μm from the interface between the WC-based cemented carbide member and the joint toward the center in the thickness direction of the joint. The composite member according to claim 1, wherein a layer and a Ti—Co layer are formed. 前記Ｃｏ−Ｓｍ層は、平均組成で２０〜８０原子％のＣｏと２０〜８０原子％のＳｍを含有し、前記ＴｉＣ層は、平均組成で９０原子％以上のＴｉＣを含有し、前記Ｔｉ−Ｃｏ合金層は、平均組成で４５〜７５原子％のＴｉと２５〜５５原子％のＣｏを含有することを特徴とする請求項３に記載の複合部材。 The Co—Sm layer contains 20-80 atomic% Co and 20-80 atomic% Sm in average composition, the TiC layer contains 90 atomic% or more TiC in average composition, and the Ti— 4. The composite member according to claim 3, wherein the Co alloy layer contains 45 to 75 atomic% Ti and 25 to 55 atomic% Co in average composition. 請求項１乃至４のいずれか一項に記載の複合部材から構成されていることを特徴とする切削工具。









A cutting tool comprising the composite member according to any one of claims 1 to 4.