JP2004358580A - Cutting tool and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cutting tool enhanced in both wear resistance and chipping resistance of a cutting edge. <P>SOLUTION: This cutting tool is provided with a composite fiber body 1 formed by coating the outer periphery of a long-sized core material 4 with an outer skin material 8, wherein the core material 4 is composed of a diamond sintered body with diamond grains 2 bonded by a bond phase 3 consisting of iron group metal and at least one kind selected out of a group of carbide, nitride and carbonitride of at least one kind of metal element selected out of groups IVa, Va and VIa metals of the periodic table, while the outer skin material 8 is composed of a sintered alloy formed by bonding at least one kind of hard grains 6 selected out of a group of carbide, nitride and carbonitride of at least one kind of metal element selected out of groups IVa, Va and VIa metals of the periodic table, and the amount of iron group metal in the core material is 5 vol% or less. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【００６５】
表１から明らかなとおり、ＴｉＣ相を結合材とした単純なダイヤモンド質焼結体にて作製した試料Ｎｏ．１０では、切削試験初期に欠損してしまった。
【００６６】
また、Ｃｏ相を結合材とした均一な組織のダイヤモンド質焼結体にて作製した試料Ｎｏ．１１では、２００００回加工できたものの、摩耗幅が大きく、さらにチッピングが発生していた。
【００６７】
さらに、芯材中のＣｏ相量が５体積％を越える試料Ｎｏ．７では、２００００回加工できたものの、摩耗が大きく進行していた。また、被覆材として金属成分を含まないＴｉＮを被覆した試料Ｎｏ．９では、ダイヤモンド粒子の脱落により摩耗が進行して耐摩耗性が低いものであった。
【００６８】
これに対して、本発明に従って作製した試料Ｎｏ．１〜６とＮｏ．８では、いずれも摩耗量が少なく、かつチッピングや欠損の発生のないものであった。また、試料Ｎｏ．１〜６についてマイクロビッカース硬度計にて荷重９８ｋＰａ（１ｋｇｆ）にてビッカース硬度Ｈｖを測定したところいずれも４５ＧＰａ以上の硬度を有することがわかった。
【００６９】
【発明の効果】
以上詳述したとおり、本発明によれば、各種材料を加工するための切削工具において、単純で均一な組織からなる従来の焼結体に代えて、ダイヤモンド粒子間を周期律表４ａ、５ａ、６ａ族金属の群から選ばれる少なくとも１種以上の金属元素の炭化物および炭窒化物の群から選ばれる少なくとも１種以上と鉄族金属にて結合したダイヤモンド質焼結体からなる長尺状の芯材の外周を、周期律表４ａ、５ａ、６ａ族金属の群から選ばれる少なくとも１種以上の金属元素の炭化物、窒化物および炭窒化物の群から選ばれる少なくとも１種以上の硬質粒子を鉄属金属にて結合した焼結合金からなる表皮材にて被覆してなる複合構造体であって、前記芯材中の鉄属金属量が５体積％以下とすることによって、耐摩耗性と耐欠損性を両立した優れた切削工具を形成できる。
【図面の簡単な説明】
【図１】本発明の複合構造体の一例を示す概略断面図である。
【図２】本発明にかかる切削工具の複合繊維体の構造を示す、（ａ）シングルタイプ、（ｂ）マルチタイプの斜視図である。
【図３】本発明にかかる切削工具の一実施形態を示す（ａ）斜視図、（ｂ）切刃チップ付近の断面図である。
【図４】図３の切刃チップのすくい面側から見た上面図である。
【図５】本発明の他の実施態様についての上面図である。
【図６】本発明にかかる切削工具の複合構造体の構造を説明するための概略斜視図である。
【図７】本発明にかかる切削工具のシングルタイプの複合繊維体の製造方法を示す工程図である。
【図８】本発明にかかる切削工具のマルチタイプの複合繊維体の製造方法を示す工程図である。
【図９】本発明にかかる切削工具の複合積層体の製造方法の一例を示す概略図である。
【符号の説明】
１ 複合繊維体
１ａ 複合成形体
１ｓ 複合繊維体（シングルタイプ）
１ｍ 集束繊維体（マルチタイプ）
２ ダイヤモンド粒子
３ 結合相
４ 芯材（ダイヤモンド質焼結体）
４ａ 芯材用成形体
６ 硬質粒子
７ 鉄族金属
８ 表皮材（焼結合金）
８ａ 表皮材用成形体
９ 複合構造体
９ｓ 単層の複合構造体（複合シート）
９ｍ 多層の複合構造体
１１ 切削工具
１２ 切刃チップ
１３ 工具本体
１４ 取付座
１５ すくい面
１６ 着座面
１７ 逃げ面
１８ 切刃稜
１９ 裏打板
２０ 取付孔
２１ 直線部
２２ つなぎ部
３１ 集束体
３２ 複合積層体
４１ 押出機
４２ ローラ[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a cutting tool using a composite structure in which a core material made of a diamond-based sintered body is covered with a skin material made of a sintered alloy such as a cemented carbide or cermet.
[0002]
[Prior art]
The cutting edge of a throw-away tip used as a cutting tool for processing various materials such as steel is generally formed of a cemented carbide or the like. This cutting tool is widely used from precision cutting to general-purpose cutting, on the other hand, diamond is a diamond-based sintered body that combines diamond particles with an iron-based metal, taking advantage of the property of having high hardness, It is used as a cutting tool or a drilling tool or a wear-resistant member.
[0003]
In such conventional cutting tools, hardness and fracture toughness are incompatible properties, and it is difficult to achieve both wear resistance, chipping resistance, and chipping resistance. At the same time. In addition, although the conventional diamond-based sintered body shows excellent wear resistance due to high hardness and high thermal conductivity, since the iron-group metal is used as a binder, the low properties of the iron-group metal, particularly hardness, Due to the reaction resistance and oxidation resistance, mechanical abrasion, oxidation due to cutting heat, reaction with the work material, diffusion of the work material components, and the like proceeded, thereby inhibiting excellent wear resistance.
[0004]
Therefore, according to Patent Document 1, the diamond particles are bonded by bonding the periphery of the diamond particles with a bonding material made of a carbide formed by melting Ti, Si, Zr, Mo, W, Ta, Nb, or the like. It is proposed that the power be improved.
[0005]
Further, according to Patent Document 2, a highly tough composite fiber body in which a skin material made of WC or the like is arranged on the outer periphery of a long core material made of a diamond-based sintered body is disclosed. It has been proposed to improve the chipping resistance of a drilling tool by attaching the tool so that the entire peripheral surface of the cutting edge has a cross-section of the converged body.
[0006]
[Patent Document 1]
JP 2003-95743 A
[0007]
[Patent Document 2]
U.S. Pat.No. 6,063,502
[0008]
[Problems to be solved by the invention]
However, as described in Patent Document 1, a diamond-based sintered body in which diamond powder and a metal raw material are mixed and heated and melted at the time of sintering to form a carbide, the carbide is contained in the diamond-based sintered body as a binder phase. Although the hardness of the sintered body is increased by dispersing, there is a problem that the toughness is reduced, and the dispersion of the carbide in the structure of the sintered body is uneven and the characteristics of the sintered body are large. . Furthermore, Patent Document 1 does not discuss at all a specific effect on cutting characteristics when the structure is used as a cutting tool, and its configuration is not suitable for a cutting tool.
[0009]
Patent Document 2 describes a specific example for an excavating tool, but does not describe a cutting tool such as turning or milling, and applies a composite fiber body to such a cutting tool. A specific structure for sufficiently exhibiting the properties of the fibrous body at that time has not been studied at all.
[0010]
Therefore, an object of the present invention is to provide a composite structure in which a core material is made of a diamond sintered body, to provide a skin material on the outer periphery of the core material to increase the toughness and to improve the hardness while maintaining the sinterability of the core material. And to provide a cutting tool having both high fracture resistance and high wear resistance.
[0011]
[Means for Solving the Problems]
The present inventors have studied the above problems and found that, in a cutting tool for processing various materials, a core material and a skin material thereof are used instead of a conventional sintered body having a simple and uniform structure. Using a composite structure obtained by bundling composite fibrous bodies composed of a skin material, at least selected from the group consisting of Group 4a, 5a, and 6a group metals having excellent hardness, reaction resistance, and oxidation resistance particularly for the core material. Using a diamond-like sintered body in which diamond particles are uniformly dispersed in a binder comprising at least one selected from the group consisting of carbides and carbonitrides of one or more metal elements, to provide an excellent skin material with excellent toughness. It has been found that by using a sintered alloy such as a cemented carbide or a cermet, a composite structure having excellent cutting characteristics that achieves both wear resistance and fracture resistance is obtained.
[0012]
That is, in the cutting tool of the present invention, between the diamond particles, at least one or more selected from the group consisting of carbides and carbonitrides of at least one metal element selected from the group of metals in the periodic table 4a, 5a and 6a. The outer periphery of a long core material made of a diamond-based sintered body bonded by the method described above is used to form carbides, nitrides, and carbons of at least one or more metal elements selected from the group of metals of Group 4a, 5a, and 6a in the periodic table. A composite structure comprising at least one hard particle selected from a group of nitrides covered with a skin material made of a sintered alloy in which the particles are bonded with an iron group metal, wherein the iron group metal in the core material is provided. A cutting tool having an amount of 5% by volume or less.
[0013]
Here, 90% or more of the diamond particles are included in the carbides and carbonitrides of at least one metal element selected from the group of metals of Group 4a, 5a and 6a of the periodic table. This has the effect of strengthening the adhesion between the diamond and the binder and preventing the diamond particles from falling off.
[0014]
Further, when the Vickers hardness Hv of the core material is 45 GPa or more, there is an effect that the wear resistance of the entire composite structure is further improved.
[0015]
Further, the average particle diameter d of the diamond particles contained in the core material ₁ Is preferably 0.1 to 3.5 μm from the viewpoint of improving the fracture resistance.
[0016]
Further, it is desirable that the content ratio of diamond particles in the diamond sintered body is 70% by volume or more from the viewpoint of increasing the hardness of the core material and increasing the wear resistance of the cutting tool.
[0017]
Further, in order to obtain the above cutting tool, (a) a mixture of diamond particles coated with a coating layer containing at least one metal selected from Group 4a, 5a and 6a metals and an organic binder is used. (B) forming a molded body for a skin material having a composition different from that of the molded body in the step (a), and forming the molded body for a core material in the step (a). (C) causing the diamond particles and the metal in the coating layer to react with each other during firing in the core material so as to cover the outer periphery of the molded body; A diamond-like sintered body is formed by bonding at least one or more selected from the group consisting of carbides and carbonitrides of at least one metal element selected from the group of metals in the periodic table 4a, 5a and 6a. You It is characterized in that it comprises a step.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the cutting tool according to the present invention will be described in detail with reference to FIG. 1 which is a schematic view of a composite fiber body contained therein.
[0019]
According to FIG. 1, the composite fiber body 1 includes a diamond particle 2 and a diamond particle 2 formed from a group of carbides and carbonitrides of at least one or more metal elements selected from the group of periodic table 4a, 5a, and 6a group metals. The outer periphery of the long core material 4 made of a diamond-like sintered body bonded by at least one or more selected binder phases 3 is at least one member selected from the group consisting of group metals of the periodic table 4a, 5a and 6a. Hard particles 6 made of at least one of the above-mentioned carbides, nitrides and carbonitrides of the metal elements are covered with a skin material 8 made of a sintered alloy bonded with an iron group metal 7.
[0020]
According to the present invention, it is a great feature that the amount of iron group metal in the core material 4 which is a diamond-based sintered body is 5% by volume or less, whereby the hardness of the core material 4 is improved and the wear resistance is improved. The composite fiber body 1 having excellent cutting characteristics and having both high fracture resistance and fracture resistance can be produced.
[0021]
That is, the diamond sintered body 4 obtained by bonding the diamond particles 2 with a binder having excellent hardness, reaction resistance and oxidation resistance is coated with a skin material 8 having excellent toughness. By holding the composite fiber body 1, the composite fibrous body 1 has high toughness, and has improved fracture resistance and chipping resistance, as well as improved wear resistance against mechanical wear, oxidative wear, diffusion wear and adhesive wear. Further, in the case where a diamond powder having a simple structure is mixed with a binder other than an iron group metal phase and a binder phase powder forming a carbonitride without using a coated diamond powder as a raw material, it is difficult to retain the diamond particles 2, While the abrasion resistance is lowered due to the falling off of the diamond particles 2, the diamond particles 2 firmly bound by the carbide or carbonitride phase formed by the reaction are firmly held by the hard phase containing the iron group metal. Accordingly, there is an effect that the wear resistance of the composite fiber body 1 is improved without the diamond particles 2 dispersed in the sintered body falling off.
[0022]
The reason why the content of the iron group metal is set to 5% by volume or less is that if the content of the iron group metal is more than 5% by volume, excellent hardness, reaction resistance and oxidation resistance are impaired, and wear resistance is reduced. Particularly preferred is 2% by volume or less.
[0023]
Further, as the bonding phase 3 of the core material 4 in the present invention, a material composed of at least one selected from the group consisting of carbides and carbonitrides of metals of the periodic table 4a, 5a and 6a is used.
[0024]
Specifically, the material constituting the binding phase 3 of the core material 4 may be one or more hard particles of carbides, nitrides, and carbonitrides of metals belonging to the periodic table 4a, 5a, and 6a. , Titanium carbide, titanium carbonitride, tantalum carbide, niobium carbide, zirconium carbide, zirconium nitride, vanadium carbide, at least one selected from the group of chromium carbide and molybdenum carbide, at least selected from the group of titanium carbide or titanium carbonitride One type can be suitably used. When the iron group metal is contained at 5% by volume or less, the iron group metal also functions as a binder phase.
[0025]
In addition, 90% or more of the diamond particles 2 are included in carbides and / or carbonitrides of at least one metal element selected from the group consisting of metals of groups 4a, 5a and 6a of the periodic table. However, it is desirable in that a decrease in wear resistance due to the falling off of the diamond particles 2 is suppressed. In the present invention, it is determined whether or not the diamond particles 2 are included in carbides and / or carbonitrides of at least one metal element selected from the group of metals in the periodic table 4a, 5a, and 6a. It can be quantified by contrast by a backscattered electron image (BEI) in a scanning electron micrograph of a cross section of the structure or by composition mapping by electron probe microanalysis (EPMA). Refers to a state in which 80% or more of the outer peripheral surface is in contact with carbides and carbonitrides of at least one or more metal elements selected from the group of metals in Groups 4a, 5a and 6a of the periodic table.
[0026]
Further, it is desirable that the Vickers hardness Hv of the core material 4 be 45 GPa or more, since the hardness of the composite fiber body 1 is remarkably improved, and the wear resistance against mechanical wear of the cutting tool is remarkably improved.
[0027]
On the other hand, the average particle diameter d of the diamond particles 2 of the sintered body forming the core material 4 ₁ Is preferably from 0.1 to 3.5 μm, and more preferably from 0.1 to 3.5 μm, in order to improve the hardness and strength of the composite fibrous body 31, prevent aggregation of the diamond particles, and increase the holding power to prevent the diamond particles from falling off. Desirably, it is 2 μm.
[0028]
Further, the content ratio of diamond particles in the diamond sintered body constituting the core material 4 is 70% by volume or more, particularly 90% by volume or more in terms of increasing the hardness of the core material and increasing the wear resistance of the cutting tool. desirable.
[0029]
Further, the content of the residual carbon in the diamond-based sintered body is 5% by volume or less, and the porosity in the diamond-based sintered body is 0.5% by volume or less. This is desirable in that the strength is improved and the fracture resistance of the cutting tool is increased.
[0030]
On the other hand, as the skin material 8 covering the outer periphery of the core material 4, at least one or more hard particles selected from the group consisting of carbides, nitrides, and carbonitrides of metals belonging to the periodic table 4a, 5a, and 6a are made of iron group metal. Use a material bound at 3-50% by volume, especially 6-30% by volume.
[0031]
Specifically, the material constituting the skin material 8 includes one or more hard particles of carbides, nitrides, and carbonitrides of metals belonging to the periodic table 4a, 5a, and 6a, and in particular, tungsten carbide, titanium carbide, At least one selected from the group consisting of titanium carbonitride, titanium nitride, tantalum carbide, niobium carbide, zirconium carbide, zirconium nitride, vanadium carbide, chromium carbide and molybdenum carbide, and further from the group of tungsten carbide, titanium carbide or titanium carbonitride Hardness obtained by bonding at least one selected from 50 to 97% by volume, in particular, tungsten carbide, titanium carbide or titanium carbonitride by 3 to 50% by volume of a bonding metal composed of an iron group metal, particularly cobalt and / or nickel. A sintered body, that is, a cemented carbide or cermet can be suitably used.
[0032]
Here, FIGS. 2A and 2B are schematic perspective views of the composite fiber used in the present invention. The composite fibrous body 1s of (a) is a single-type fibrous body composed of a core material 4 and a skin material 8 covering the outer periphery of the core material 4 and having a composition different from that of the core material 4. Further, the composite fiber 1m in (b) is a multi-type fiber obtained by extending the aggregate of the single-type fiber in (a). According to the present invention, the composite structure 9 forming the cutting edge 18 in FIG. 3 is formed by a structure in which the composite fiber 1 of (a) or (b) is converged. Desirably, use of the multi-type fibrous body of (b) is excellent in fracture resistance.
[0033]
The size of the composite fibrous body 1 is 5 to 300 μm in diameter, and the composite fibrous body including the skin material 8 is used in order to improve the adhesion to the backing plate 19 and the fracture resistance as the tool 11. It is desirable that the diameter of one piece is 6 to 500 μm.
[0034]
Also, as shown in FIG. 4, which is a top view of the cutting blade tip 12 portion of the cutting tool 11 in FIG. 3, a plurality of composite fiber bodies 1, 1,... Fiber direction L _f And the tangent L at the ridge line at the cutting edge 18 _C The angle θ at any point in the cutting edge portion, that is, the angle θ at point 1 on the cutting edge 18. ₁ , The angle θ at point 2 ₂ , The angle θ at point 3 ₃ In any of the above, the angle θ is 2 ° or more, preferably 5 ° or more, more preferably 10 ° or more, depending on the boundary direction of the composite fiber body 1 in which the direction of the highest stress applied during cutting is arranged, or By deviating from the interface direction between the core material 4 and the skin material 8 of the fibrous body 1, stress due to cutting is prevented from being concentrated on this interface, and the generated stress is reduced in strength and toughness. Are desirably dispersed in the longitudinal direction to enhance chipping resistance and chipping resistance at the cutting edge ridgeline 18.
[0035]
The angle θ is determined by adjusting the arrangement direction of the composite fibrous body 1 in the composite fibrous body 1 with respect to the tool shape and the area where the cutting edge 18 is formed, that is, the tool shape itself such as the shape of the nose R and the angle r. Is controlled by For example, when the angle r of the nose R portion is less than 90 °, particularly 80 ° or less, and even 60 ° or less, so-called T, D, and V type shape throw-away tips in which the rake face 15 is formed in a triangular or rhombic shape are applicable. is there. According to FIG. 4, the nose R portion extends from the vertex (P) in both directions and means a ridge line extending from the vertex (P) to the joint portion 22 which is a boundary with the linear portion 21.
[0036]
Incidentally, according to FIG. 4, the fiber direction L of the composite fiber body 1 is shown. _f And tangent L at vertex P of nose R _c2 Angle θ (θ ₂ ) Is 90 °, that is, the fiber direction L of the composite fiber body 1 _f Are arranged so as to extend vertically toward the apex P of the nose R portion. In the case of a so-called S-type indexable insert in which the rake face 15 has a square shape and the angle r of the nose R is 90 °, only one side of the nose R portion has a cutting edge 18 as shown in FIG. And the opposite side 23 is not used as a cutting edge, that is, if it is a throwaway tip limited to right-handed or left-handed, the fiber direction L of the composite fiber body 1 _f And the tangent L at each cutting edge position _C1 And the fiber direction L of the composite fibrous body 1 _f And tangent L at vertex P of nose R _c2 May be 45 ° or less.
[0037]
Further, according to the present invention, as shown in FIG. 6, the composite structure 9 is composed of a plurality of composite fiber bodies 1 arranged in one direction and aligned, and as shown in FIG. However, a multi-layered composite structure 9m in which a plurality of single-layered composite structures 9s are stacked in the thickness direction is preferable because a higher stress dispersion effect can be obtained.
[0038]
In addition, according to the present invention, as shown in FIG. 6C, when fabricating a composite structure 9m having a multilayer structure, adjacent composite sheets 9s, 9s are laminated so that the orientation of the composite fiber body 1 is different. Therefore, the toughness of the composite structure 9m can be further increased, and the fracture resistance of the cutting tool 11 can be further improved.
[0039]
Further, the fiber direction of the composite fiber body 1 may be parallel to the rake face 15 or the angle between the fiber direction of the composite fiber body 1 and the bearing surface of the tool body 13 may be in the range of 0 ° to 30 °. It is desirable in that the chipping resistance and chipping resistance on the rake face 15 of the cutting edge ridgeline 18 can be improved, and the wear resistance on the flank 17 can be improved.
[0040]
According to the present invention, the cutting tool may be a solid type tool, but is preferably a throw-away type tool in terms of low cost, ease of manufacture, and the like.
[0041]
Further, as shown in FIG. 3, the cutting tool of the present invention cuts the cutting edge portion of the tool body 13 and mounts the cutting blade tip 12 having the composite structure 9 composed of the composite fiber body 1 (1 s, 1 m) on the mounting seat. 14, the fiber direction of the composite fiber body 1 with respect to the cutting edge shape of the tool can be easily controlled, and the cutting edge 18 is provided at a plurality of corners. Also in this case, there is an advantage that the composite fiber body 1 can be easily arranged.
[0042]
○ Manufacturing method
Next, a method for manufacturing the composite structure of the present invention will be described with reference to the schematic diagrams of FIGS.
[0043]
In producing the composite fiber body 1, first, the core molded body 4a is produced. As a specific method, first, at least one or more metal elements selected from the group of metals in the periodic table 4a, 5a, and 6a having an average particle diameter of 0.01 to 10 μm, particularly 0.1 to 3.5 μm are used. Diamond powder coated by physical vapor deposition (vacuum vapor deposition, sputtering, ion plating, etc.), chemical vapor deposition (thermal CVD, plasma CVD, etc.), sol-gel method, plating method, etc. 50% by mass or more, particularly 80% by mass or more, and optionally 50% by mass or less of an iron group metal powder having an average particle size of 0.01 to 10 μm, and further mixed with an organic binder, a plasticizer, and a solvent. The mixture is added and kneaded, and is molded into a cylindrical shape by a molding method such as press molding or cast molding to produce a core material molded body 4a (see FIG. 7A).
[0044]
Here, in order to obtain a homogeneous composite molded article by co-extrusion molding described below, the amount of the organic binder to be added is desirably 50 to 200 parts by volume, particularly preferably 70 to 150 parts by volume.
[0045]
As the organic binder, paraffin wax, polystyrene, polyethylene, ethylene-ethyl acrylate, ethylene-vinyl acetate, polybutyl methacrylate, polyethylene glycol, dibutyl phthalate and the like can be used.
[0046]
On the other hand, a material constituting a skin material having a composition different from that of the core material molded body 4a is kneaded with the binder described above, and two half-cylindrical skin materials are formed by a molding method such as press molding, extrusion molding, or casting. A molded body 8a is prepared. The molded body 1a in which the molded body for skin material 8a is arranged so as to cover the outer periphery of the molded body for core material 4a is produced (see FIGS. 7B and 7C).
[0047]
Then, the extruder 100 is used to co-extrude the molded body 1a including the molded body for core material 4a and the molded body for skin material 8a to form a molded body for skin material around the molded body for core material 4a. A single-type composite fibrous body 1s of FIG. 2 (a) coated with 8a and elongated to a small diameter can be produced (see FIG. 7 (d)).
[0048]
Further, in forming the composite fiber body 1, as shown in FIG. 8, a bundle 31 in which a plurality of the coextruded long composite fiber bodies 1s are bundled is co-extruded again to form the composite fiber body 1 shown in FIG. 1), a multi-type composite fiber 1m having a high fiber density can be produced. The cross sections of the composite fiber bodies 1s and 1m may be not only circular but also quadrangular or triangular.
[0049]
Then, as shown in FIGS. 6A to 6C, the long composite fiber bodies 1 are arranged in 2 to 100 rows, and heated and pressed in a mold to obtain a composite sheet 9s. Accordingly, a plurality of the composite sheets 9s are stacked in the thickness direction such that the directions of the composite fiber bodies 1 of the adjacent composite sheets 9s and 9s are different from each other, thereby forming a multilayer composite. A structure 9m is obtained. However, in this case, the fiber direction of the composite fiber body 1 in the uppermost composite sheet 9s forming the cutting edge of the composite sheet 9s is adjusted so as to be at a specific angle in relation to the cutting edge ridge line 18 as described above. It is desirable to do.
[0050]
In addition, as shown in FIG. 9, the composite structure 9m may be passed through a pair of rollers 42 and rolled to produce a higher-density composite laminate 32, if necessary.
[0051]
Then, the single-layer composite sheet 9s, the multilayer composite structure 9m, or the composite laminate 32 is placed on the backing plate 19 made of cemented carbide, and the temperature is raised or held at 300 to 700 ° C for 10 to 200 hours. The binder is removed and then set in an ultra-high pressure device, and then integrated by baking at a pressure of 4 to 6 GPa, a temperature of 1350 to 1600 ° C., a time of 1 to 60 minutes, particularly 1 to 10 minutes. The cutting edge chip 12 composed of the composite structure 9 or the composite laminate 32 joined and integrated with the backing plate 19 can be manufactured.
[0052]
According to the present invention, the metal component in the coating layer coated on the diamond particles reacts with the carbon of the diamond particles to form a structure in which the outer peripheral surfaces of the diamond particles are bonded by carbide and / or carbonitride. In addition, carbides or carbonitrides generated by volume expansion due to carbonization generate compressive residual stress in the diamond particles, so that a diamond-like sintered body more firmly bonded can be produced.
[0053]
Further, according to the present invention, the iron group metal present in the molded body for skin material 8a at the time of the above-mentioned firing may be diffused into the molded body for the core material 4a. The content of the iron group metal therein can be controlled to 5% by volume or less.
[0054]
The composite structure 9 is processed into a cutting edge shape by a wire electric discharge machine, cutting, polishing, or the like so that the relationship with the cutting edge 18 of the cutting tool 11 becomes the predetermined angle θ as described above.
[0055]
Then, the cutting edge chip 12 in which the backing plate 19 and the composite structure 9 are integrated is brazed to the mounting seat 14 using silver brazing or the like.
[0056]
【Example】
Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited to the following Examples.
[0057]
100 parts by volume of cellulose and polyethylene glycol as organic binders and 100 parts by volume of polyvinyl alcohol as solvents are added and kneaded to a diamond powder coated with a metal from Groups 4a, 5a and 6a of the periodic table as shown in Table 1 by an ion plating method. Then, it was press-molded into a cylindrical shape having a diameter of 20 mm to prepare a molded body for a core material. The coating amount of the coating layer on the diamond powder is shown in Table 1 by calculating the difference in mass before and after coating as the mass of the coating layer.
[0058]
On the other hand, WC powder and TiCN powder having an average particle diameter of the hard particles in the sintered body constituting the skin material as shown in Table 1 were added to TiC powder having an average particle diameter of 2 μm so that the sintered body had the composition shown in Table 1. , TiN powder, Co powder, and Ni powder are mixed, and the same organic binder and solvent as described above are added and kneaded to form a half-cylindrical shaped skin material having a thickness of 1 mm into a press. Then, these were arranged so as to cover the outer periphery of the molded body for core material, to produce a composite fiber body.
[0059]
Then, the composite fiber body is co-extruded to produce an elongated composite molded article having a diameter of 1 mm. Then, 100 elongated composite molded articles are bundled and co-extruded again to obtain a multifilament having a diameter of 1 mm. A composite fiber body having a structure was produced.
[0060]
Next, the composite fiber body having the multifilament structure was cut into a length of 100 mm, aligned in parallel to form a sheet, and three composite sheets were laminated to prepare a composite structure having a multilayer structure.
[0061]
Thereafter, WC particles having an average particle diameter of 2 μm are spread on the lower surface of the laminate, and a backing plate made of a cemented carbide having a composition of Table 1 and having a thickness of 5 mm is provided. The backing plate is heated to 300 to 700 ° C. for 100 hours. After performing the binder removal treatment by heating, the mixture was placed in an ultrahigh-pressure apparatus and baked for 5 minutes under the calcination conditions shown in Table 1 to produce a cutting edge chip in which the composite structure and the back plate were integrated. Thereafter, this cutting edge tip was processed and brazed at 700 ° C. to a mounting seat of a tool body made of a cemented carbide using a silver braze.
[0062]
In the cutting tool shown in Table 1, the fiber direction L of the composite fibrous body constituting the sheet is shown. _f And the tangent L at the cutting edge of the cutting tip _c Is 30 °, and the tip angle (nose R) is 60 °.
[0063]
For the diamond-based sintered compact cutting tool produced as described above,
Work material: ADC12, 4 grooves
Cutting depth d = 1mm
Cutting speed V = 500m / min
Feed f = 0.2mm / blade
A cutting test was performed under the conditions described above, and the number of impacts (up to 20,000 times) until chipping or chipping occurred was evaluated. For samples that could be processed 20,000 times, the amount of wear at that time was measured, and the chipping state was determined. Observed. The results are shown in Table 1.
[0064]
[Table 1]

[0065]
As is clear from Table 1, Sample No. 1 was made of a simple diamond-based sintered body using a TiC phase as a binder. In No. 10, it was lost at the beginning of the cutting test.
[0066]
In addition, Sample No. 1 was prepared from a diamond-like sintered body having a uniform structure using a Co phase as a binder. In No. 11, although machining could be performed 20,000 times, the wear width was large, and further chipping occurred.
[0067]
Further, in Sample No. in which the amount of the Co phase in the core material exceeded 5% by volume. In the case of No. 7, although the processing could be performed 20,000 times, abrasion was greatly advanced. In addition, Sample No. coated with TiN containing no metal component as a coating material. In No. 9, the abrasion progressed due to the falling of the diamond particles, and the abrasion resistance was low.
[0068]
On the other hand, for sample No. Nos. 1 to 6 and Nos. In No. 8, the amount of wear was small and no chipping or chipping occurred. Further, the sample No. When the Vickers hardness Hv of each of Nos. 1 to 6 was measured with a load of 98 kPa (1 kgf) using a micro Vickers hardness meter, it was found that each had a hardness of 45 GPa or more.
[0069]
【The invention's effect】
As described in detail above, according to the present invention, in a cutting tool for processing various materials, instead of the conventional sintered body having a simple and uniform structure, the periodic table 4a, 5a, An elongated core made of a diamond-like sintered body bonded with at least one or more selected from the group consisting of carbides and carbonitrides of at least one metal element selected from the group of 6a group metals with an iron group metal At least one hard particle selected from the group consisting of carbides, nitrides and carbonitrides of at least one metal element selected from the group consisting of metals belonging to groups 4a, 5a and 6a of the periodic table is formed on the outer periphery of the material by iron. A composite structure coated with a skin material made of a sintered alloy bonded with a metal group, wherein the amount of iron group metal in the core material is 5% by volume or less, so that wear resistance and resistance to wear are improved. Excellent cutting with both defects It can form a tool.
[Brief description of the drawings]
FIG. 1 is a schematic sectional view showing an example of a composite structure of the present invention.
FIG. 2 is a perspective view of (a) a single type and (b) a multi-type showing the structure of a composite fiber body of the cutting tool according to the present invention.
3A is a perspective view showing an embodiment of a cutting tool according to the present invention, and FIG.
FIG. 4 is a top view of the cutting edge tip of FIG. 3 as viewed from the rake face side.
FIG. 5 is a top view of another embodiment of the present invention.
FIG. 6 is a schematic perspective view for explaining the structure of the composite structure of the cutting tool according to the present invention.
FIG. 7 is a process chart showing a method for producing a single-type composite fiber body of a cutting tool according to the present invention.
FIG. 8 is a process chart showing a method for producing a multi-type composite fiber body of a cutting tool according to the present invention.
FIG. 9 is a schematic view showing an example of a method for producing a composite laminate of a cutting tool according to the present invention.
[Explanation of symbols]
1 composite fiber body
1a Composite molded body
1s composite fiber (single type)
1m bundled fiber body (multi type)
2 Diamond particles
3 bonded phase
4 core material (diamond sintered body)
4a Molding for core material
6 hard particles
7 Iron group metals
8 Skin material (sintered alloy)
8a Molding for skin material
9 Composite structure
9s Single-layer composite structure (composite sheet)
9m multilayer composite structure
11 Cutting tools
12 cutting edge tip
13 Tool body
14 Mounting seat
15 Rake surface
16 Seating surface
17 Flank
18 Cutting edge ridge
19 Backing plate
20 mounting holes
21 Straight section
22 Connecting part
31 Converged body
32 Composite laminate
41 Extruder
42 rollers

Claims (6)

A diamond-based sintered body in which diamond particles are bonded by at least one or more selected from the group consisting of carbides and carbonitrides of at least one metal element selected from the group consisting of metals in the periodic table 4a, 5a, and 6a. The outer periphery of a long core material made of at least one metal selected from the group consisting of carbides, nitrides, and carbonitrides of at least one metal element selected from the group of metals in the periodic table 4a, 5a, and 6a. At least one kind of hard particles is covered with a skin material made of a sintered alloy combined with an iron group metal, and the core material has a composite fiber body having an iron group metal content of 5% by volume or less. And cutting tools. 90% or more of the diamond particles have at least one selected from the group consisting of carbides and carbonitrides of at least one metal element selected from the group of metals in the periodic table 4a, 5a and 6a. The cutting tool according to claim 1, wherein the cutting tool is included. 3. The cutting tool according to claim 1, wherein the core material has a Vickers hardness Hv of 45 GPa or more. Cutting tool according to any one of claims 1 to 3, wherein the average particle size d ₁ of the diamond particles contained in the core material is 0.1～3.5Myuemu. The cutting tool according to any one of claims 1 to 4, wherein the content ratio of the diamond particles in the diamond sintered body is 70% by volume or more. (A) A mixture of diamond particles coated with a coating layer containing at least one selected from metals of Groups 4a, 5a and 6a of the periodic table and an organic binder is molded into a long shape to form a molded body for a core material. A step of making;
(B) A composite molded article formed by molding a molded article for a skin material having a composition different from that of the molded article in the step (a) and arranging the molded article for a core material in the step (a) so as to cover the outer periphery of the molded article. A step of making;
(C) in the core material, the diamond particles and the metal in the coating layer are reacted during firing, and at least one kind selected from the group of metals in the periodic table 4a, 5a, or 6a is formed between the diamond particles. Producing a diamond-like sintered body bonded by at least one or more selected from the group consisting of a carbide and a carbonitride of a metal element.

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