JP3235206B2 - Diamond cutting tool and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diamond cutting tool, and more particularly to a cutting tool using diamond formed by vapor phase synthesis for its cutting edge and having excellent wear resistance, heat resistance and chipping resistance, and a method for producing the same. .

[0002]

2. Description of the Related Art Diamond is particularly useful as a tool material for cutting difficult-to-cut materials because of its high hardness and thermal conductivity.

[0003] Diamond used as a tool material is classified into a single crystal type and a polycrystalline type. Single crystal diamond is a material excellent in its physical properties, but is very expensive and has a drawback that it is not easy to process it into a desired shape as a tool material and that it is cleaved. .

On the other hand, polycrystalline diamond as a tool material can be roughly classified into two types. One of them is a sintered diamond obtained by sintering a fine diamond powder with iron group metal such as Co under ultra-high pressure and high temperature in which diamond is stable. Such sintering technology is
For example, it is described in Japanese Patent Publication No. 52-12126.

[0005] Among the commercially available sintered diamonds,
In particular, those having a particle size of several tens of μm or less are known to have excellent wear resistance without causing a cleavage phenomenon as seen in the above-mentioned single crystal diamond.

[0006] However, sintered diamond is a few percent.
Since the binder contains about 10% to several tens of percent, the diamond particles constituting the sintered body fall off during cutting, and the cutting edge of the diamond may be chipped. Since the drop-off phenomenon becomes more remarkable as the wedge angle of the tool edge becomes smaller, it has been difficult to extend the life of a sharp edge made of sintered diamond.

Furthermore, since sintered diamond contains a binder, it has lower heat resistance than a single crystal, and wear during cutting is apt to progress.

On the other hand, vapor-phase synthetic diamond, which is another polycrystalline diamond for cutting tools, is dense,
In addition, since it is composed of diamond alone, it has better heat resistance and wear resistance than crystalline diamond, and hardly generates defects. Such a vapor-phase synthetic diamond is generally produced by chemical vapor deposition (CVD) in which a raw material gas mainly composed of a hydrocarbon such as methane and hydrogen is decomposed and excited under a low pressure.

As a cutting tool using vapor-phase synthetic diamond, for example, a diamond coating tool in which diamond is directly coated on a tool substrate has been developed.
However, in the case of a diamond-coated tool, the adhesion between the tool substrate and the diamond thin film is important. For example, in a tool in which a diamond thin film is formed on a cemented carbide, the diamond thin film tends to peel during cutting. .

[0010] Development of a diamond cutting tool for directly brazing vapor-phase synthetic diamond to a tool base has also been carried out. For example, JP-A-1-153228 and JP-A-1-210201 disclose a technique in which a tool substrate made of a cemented carbide is directly brazed together with a substrate coated with a vapor-phase synthetic diamond to serve as a cutting tool. ing. However, such a tool cannot be used as a tool without the step of polishing the base material on the rake face,
Further, there is a problem that the wear resistance and fracture resistance are still insufficient for hard work materials.

[0011]

As described above, in a normal vapor-phase synthetic diamond, the diamond surface immediately after the vapor-phase synthesis is rough, and the grain size increases as the diamond grows, so that the diamond has a hexahedral or octahedral structure peculiar to diamond. Have.
By the way, if it is desired to make this a rake face of the cutting edge, it is necessary to perform a polishing finish. Therefore, in order to facilitate the finishing process, diamond synthesized on the base material by vapor phase is
In many cases, the (100) plane and / or the (110) plane are formed so as to be oriented parallel to the substrate plane.

Therefore, in many cases, the rake face of the cutting edge is constituted by the (100) plane or the (110) plane.

However, such (100) and (110) planes are preferable from the viewpoint of the above-mentioned polishing finish, but the diamond grain size is large, and as a cutting tool, wear resistance and chipping resistance are obtained. It was not optimal in terms of gender.

An object of the present invention is to provide a diamond cutting tool having more excellent wear resistance and chipping resistance than conventional ones.

[0015]

A diamond cutting tool according to a first aspect of the present invention is a cutting tool having a cutting edge made of a diamond material synthesized in a vapor phase, wherein a main diamond crystal face forming a rake face of the cutting edge is (311). ) Surface.

In the cutting edge according to the first aspect of the present invention, it is preferable that the (311) plane is oriented as parallel as possible as a rake surface as a main surface at a depth of at least 20 μm from the rake surface.

In the rake face and its vicinity (for example, up to a depth of 20 μm from the rake face), it is preferable to suppress the inclusion of crystal planes other than the (311) plane as much as possible. Strength of 1
00, (111) plane, (220) plane, (40) plane
The strengths of the (0) plane and the (331) plane are each preferably 80 or less, and more preferably 10 or less.

Further, in the cutting edge according to the first invention,
As an index of the orientation of the (311) plane, the FWHM value (Full Width at Half) of the rocking curve of the (311) plane obtained by incidence of X-rays from the rake face.
Maximum Intensity is more preferably within 20 °. The FWHM value of the rocking curve of the (220) plane is preferably 20 ° or more.

Further, in the first aspect, it is preferable that the rake face has a surface roughness R _max of 0.5 μm or less.

Further, it is possible to provide a method for manufacturing the diamond cutting tool according to the first invention.

According to a second aspect of the present invention, there is provided a method of preparing a base material having a mirror-finished surface on which diamond is to be deposited, and a step of preparing a base material having a (311) plane oriented substantially parallel to the above-mentioned surface. A step of depositing diamond on the surface by synthesis, a step of separating or removing a substrate on which diamond is deposited to obtain a diamond material as a cutting edge, and a step of contacting the diamond material with the substrate side. Brazing a diamond material to the tool base as a rake face of the cutting edge.

A manufacturing method according to a third aspect of the present invention includes a step of preparing a base material having a surface-finished surface on which diamond is to be deposited, and a step of preparing a base material having a (311) plane oriented substantially parallel to the surface. A step of depositing diamond on the surface by synthesis, a step of separating or removing a base material on which diamond is deposited to obtain a diamond material as a cutting edge, and a rake of the cutting edge on the diamond material at the end face of crystal growth. And a step of brazing the diamond material to the tool base as the surface side, and further, after the diamond deposition step or the brazing step, the growth end surface side of the crystal growth of the vapor-phase synthesized diamond is mirror-polished. And a step.

A manufacturing method according to a fourth aspect of the present invention comprises a step of preparing a substrate having a surface having a surface to which diamond is to be deposited, and a step of preparing a substrate so that the (311) plane is oriented substantially parallel to the plane. A step of depositing diamond on the surface by synthesis, and a step of depositing the diamond-deposited base material on the tool base such that the main diamond crystal plane constituting the rake face of the cutting edge is the (311) plane by the diamond deposition step. Further comprising, after the diamond deposition step or the brazing step, a step of mirror-polishing the end face side of the crystal growth of the vapor-phase synthesized diamond.

The manufacturing method according to a fifth aspect of the present invention includes a step of preparing a substrate having a surface-finished surface on which diamond is to be deposited, and a step of preparing a substrate so that the (311) plane is oriented substantially parallel to the surface. A step of depositing diamond on the surface by synthesis, a step of brazing the end face of the diamond crystal growth of the base material on which the diamond is deposited in the diamond deposition step to a tool base, and forming a rake face of the cutting edge. The main diamond crystal plane is (311)
Separating or removing the substrate so as to form a surface.

In the first to fifth inventions, various vapor phase synthesis methods can be applied to the formation of diamond by vapor phase synthesis. For example, a CVD method in which a raw material gas is decomposed and excited using a hot filament or plasma discharge, or a CVD method using a combustion flame is effective.

Examples of the raw material gas include hydrocarbons such as methane, ethane, and propane; methanol;
A gas in which an organic carbon compound such as alcohols or esters such as ethanol and hydrogen are mixed as main components can be used. In addition, an inert gas such as argon, oxygen, carbon monoxide, water, and the like may be contained in the raw material as long as the synthesis reaction of diamond and its characteristics are not impaired.

In the second to fifth aspects of the present invention, the (311) plane can be usually formed by lowering the carbon concentration (for hydrogen gas, for example) in the above-mentioned CVD.

The base material for the vapor phase synthesis is, for example, S
i and Mo are preferably used. Such a base material can be separated and removed from diamond by melting or separating by mechanical processing or chemical treatment.

In the method of the second invention, after separating or removing the base material, the remaining diamond may be subjected to the next step as it is, or may be processed to an appropriate size by, for example, cutting or the like. .

[0030] In the method according to the second invention, the surface of the substrate to the diamond is formed, a surface roughness R _max is 1
It is more preferable that the mirror finish is performed so as to be not more than μm, preferably not more than 0.2 μm.

In the method of the second invention, the diamond material obtained by separating or removing the substrate after the vapor phase synthesis is brazed to the tool base. In brazing, the diamond surface side that has been in contact with the base material, that is, the crystal growth start surface side is set as the rake face side of the cutting edge. Therefore,
The surface side opposite to this surface side, that is, the end surface side of the crystal growth, is usually a brazing surface.

The surfaces to be brazed include groups IVA, IVB, VA, VB, VV of the periodic table.
It is preferable that a metallized layer composed of any of the metals included in Group IA, Group VIB, Group VIIA, and Group VIIB and any of these compounds be formed prior to brazing. Brazing can be effectively performed through this metallized layer.

[0033] In the method of the third invention, the diamond material as the cutting edge is brazed to the tool base with the end face of the crystal growth of the diamond being the rake face. Therefore, the side of the diamond surface that has been in contact with the substrate in the vapor phase synthesis, that is, the side of the crystal growth starting surface, is the surface to be brazed. A metallized layer as described above may be formed on the surface to be brazed prior to brazing. Brazing can be effectively performed through this metallized layer.

In the method according to the third aspect of the present invention, the rake face obtained by mirror polishing has a surface roughness of, for example, R
It is desirable that _{max be} 0.2 μm or less. In addition, it is preferable to suppress the incorporation of crystal planes other than the (311) plane in the rake face obtained after mirror polishing and in the vicinity thereof (for example, from the rake face to a depth of 20 μm) as much as possible. ) Surface strength 1
00, (111) plane, (220) plane, (40) plane
The strengths of the (0) plane and the (331) plane are each preferably 90 or less, more preferably 50 or less.

In a method according to a fourth aspect of the present invention, a method of forming a cutting edge with a substrate without depositing or removing the substrate after depositing diamond on the substrate.
The diamond-deposited substrate is brazed to a tool substrate. In brazing, the diamond deposited on the substrate has the rake face of the cutting edge on the side where crystal growth ends. The surface of the substrate to be brazed may have a metallized layer as described above formed prior to brazing. Brazing can be effectively performed through this metallized layer. In the method according to the fourth invention, the surface roughness of the rake face obtained by mirror polishing is preferably the same as the surface roughness of the rake face obtained by mirror polishing in the method according to the third invention. .

In the method according to the fifth aspect of the invention, after the end face of the diamond crystal growth is brazed to the tool base, the base material is separated or removed, and the diamond crystal growth start face is used as the rake face of the cutting edge. Expose. Such a base material can be separated and removed from diamond by melting or separating by mechanical processing or chemical treatment.

This mirror polishing step may be performed after the diamond deposition step by vapor phase synthesis, or the diamond material is brazed to the tool base with the end face of crystal growth of the diamond material being the rake face of the cutting edge. May be performed after the step of

In the second to fifth inventions, the thickness of diamond deposited on the substrate by vapor phase synthesis is preferably, for example, 20 to 3000 μm.

In this specification, the term "mirror polishing" refers to not only a polishing process using ordinary diamond abrasive grains but also a reduction in surface roughness in a broad sense such as ion milling and electric discharge machining. Means the concept to let.

[0040]

In the tool according to the first invention, the rake face of the cutting edge is occupied by the (311) plane. (111) plane, (110) plane,
There is a (100) plane, which has a plane structure based on this combination.
Thus, well-known are hexahedral or octahedral structures.

For this reason, when these surfaces come out, the grain size becomes large, and the impact resistance of the tool is inferior, and the tool is easily cleaved. On the other hand, since the (311) plane does not appear as a self-shaped plane, the inside of the crystal has a fine structure. Therefore, the rake face is less likely to be chipped than in the past. Such a tool is more excellent in chipping and abrasion resistance than before.

In the method according to the second invention, first, diamond is deposited on the mirror-finished substrate surface by vapor phase synthesis. Therefore, in the diamond material obtained by separating or removing the base material after the synthesis of the diamond, the surface in contact with the base material is a mirror surface. This aspect
It is not necessary to perform polishing, or if necessary, simple polishing is sufficient.

Furthermore, since the vapor phase synthesis is performed so that the (311) plane is oriented substantially parallel to the base material plane, the surface of the diamond material which has been in contact with the base material is almost occupied by the (311) plane. . Therefore, if the diamond material is brazed to the tool base such that the surface that has been in contact with the base material becomes a rake face, it is possible to easily obtain a tool having better wear resistance and chipping resistance than the conventional case.

In the method according to the third invention, a diamond layer having a (311) plane oriented is deposited on a substrate.

When the end face of crystal growth of diamond in conventional vapor phase synthesis is almost occupied by the (111) plane, the end face of crystal growth is rough, and if a rake face is to be obtained, polishing is performed. Need
Such polishing is very difficult due to the high hardness of the (111) plane. In addition, the grain size of the diamond crystal on the growth termination surface is relatively large, and if the diamond crystal is formed as a rake surface, chipping is likely to occur when using a tool due to the high hardness of the (111) plane.

On the other hand, (31)
1) The diamond layer whose plane is oriented has low hardness,
Mirror polishing can be easily performed. In addition, when a diamond layer is deposited by vapor phase synthesis so that the (311) plane is oriented substantially parallel to the surface of the base material, the end face of crystal growth of diamond has a structure with a fine grain size. In addition, since the (311) plane is not a self-shaped surface, it is unlikely to be damaged and has excellent wear resistance. Therefore, if the diamond material is brazed to the tool base such that the ending surface of the crystal growth becomes a rake face, a tool having more excellent wear resistance and chipping resistance than the conventional one can be easily obtained.

The diamond cutting tool manufactured according to the fourth aspect of the present invention includes a diamond cutting tool manufactured according to the third aspect of the invention and a diamond material used as a cutting edge.
The effect similar to that of the third aspect of the invention is exerted only with the difference that the tool base is brazed via the base.

The fifth invention and the second invention are different from the fifth invention only in that the base material on which diamond is deposited is filtered on the tool base and then the diamond and the base material are separated or removed. The diamond cutting tool manufactured according to the fifth invention has the same effect as the diamond cutting tool manufactured according to the second invention.

According to the second to fifth aspects of the present invention,
In addition, it is possible to provide a diamond cutting tool having a rake face substantially constituted by the (311) plane. Such a tool is more excellent in wear resistance and fracture resistance than in the past.

[0050]

【Example】

Example 1 An Si substrate mirror-finished so as to have an R _{max of} 0.2 μm or less was prepared.

The filament has a diameter of 0.5 mm and a length of 10
Known hot filament C using 0 mm tungsten
Under the following conditions by the VD method, a thickness of 250 μm
m of polycrystalline diamond were deposited.

Source gas (flow rate): CH ₄ / H ₂ = 1%,
Total flow rate: 1000 cc / min Gas pressure: 30 Torr Filament temperature: 2200 ° C. Filament-substrate distance: 5 mm Substrate temperature: 700 ° C. Next, the polycrystalline diamond on the Si base material is cut into the size and shape required for the tool by laser. After that, S
The i-base was dissolved and removed to obtain a diamond cutting edge.

With respect to the cutting edge of the diamond obtained in this manner, X was determined from the diamond surface on the Si substrate side.
When X-ray diffraction was performed with incident X-rays, the peak intensity ratios of the (220) and (400) planes to the (311) plane were I (220) / I (311) and I (400) / I
(311) is 0.1 and 0.02, respectively, and (31)
1) It was found that orientation was obtained for the plane.

Further, at the obtained cutting edge, X-rays were incident from the surface in contact with the base material, and the FWHM value of the rocking curve of the (311) plane parallel to this plane was determined. As a result, the FWHM value (°) was 8 °.
Also, the FWH in the rocking curve of the (220) plane
The M value (°) was 25 °.

On the resulting diamond cutting edge, Ti and Ni having a thickness of 1 μm and 2 μm are sequentially laminated on the crystal growth ending surface Se, and the surface on which the metallized layer is formed is used as a bonding surface. The cutting edge was vacuum brazed using silver brazing to a hard metal (SPG422) base metal. R _max of the cutting edge rake face was 0.2 [mu] m.

For the tool obtained by brazing,
The main part is shown in FIG. A diamond cutting edge 2 is fixed to a predetermined region of a base metal 1 made of a superalloy via a brazing layer 3 and a metallized layer 4. The rake face 5 of the cutting edge 2 is occupied by the (311) plane. A flank 6 is formed on the end face of the cutting edge 2.

Example 2 A Si substrate was mirror-polished so as to have a surface roughness R _{max of} 0.2 μm or less.

A polycrystalline diamond having a thickness of 300 μm was formed on a mirror surface of Si under the following conditions by a known microwave plasma CVD method.

Source gas (flow rate): C ₂ H ₂ / H ₂ = 0.
2%, total flow rate 600 cc / min Gas pressure: 40 Torr Microwave output: 450 W (2.45 GHz) Substrate temperature: 650 ° C. Next, the polycrystalline diamond on the Si substrate is laser-sized to the size and shape required for the tool. After cutting, S
The i-base was dissolved and removed to obtain a diamond cutting edge.

X-ray diffraction was performed on the cutting edge of the obtained diamond. As a result, I (220) / I (31
1) was 0.6 and I (400) / I (311) was 0.08. The FWHM value of the rocking curve of the (311) plane was 10 °. Furthermore, (22
The FWHM value of the rocking curve of the 0) plane was 21 °.

Next, after a metallized layer was formed on the obtained cutting edge on the surface where crystal growth was completed in the same manner as in Example 1, brazing was performed by using silver brazing on a cemented carbide (SPG422) base metal. Done. After brazing, the surface of the diamond cutting edge that was in contact with the substrate was slightly mirror-finished to a rake surface. R _max of the rake face was 0.1 μm.

Example 3 Using a Si substrate mirror-finished so as to have R _{max of} 0.2 μm or less, hot filament CVD using the same tungsten filament as in Example 1 was carried out under the following conditions.
A polycrystalline diamond having a thickness of 250 μm was formed on the i-mirror surface.

Source gas (flow rate): CH ₄ / H ₂ = 1%
CO ₂ / CH ₄ = 0.5% Total flow rate 600 cc / min Gas pressure: 60 Torr Filament temperature: 2150 ° C. Filament-substrate distance: 7 mm Substrate temperature: 750 ° C. As a result of X-ray diffraction after diamond formation, I (220) )
/ I (311) is 0.8, and in the first diamond formation, the (311) plane is strongly oriented parallel to the substrate surface.

The diamond on the Si substrate is mirror-polished to make R _max <0.1 μm or less, then cut into a size and shape required for the tool by a laser, and then the silicon substrate is etched with hydrofluoric nitric acid. After melting and removal, a diamond cutting edge was obtained.

In the obtained diamond cutting edge, a Ti having a thickness of 1 μm and a thickness of 2 μm
After sequentially laminating Ni with m, the cutting edge was vacuum brazed using silver brazing to a base metal of cemented carbide (SPG422) using the surface on which the metallized layer was formed as a bonding surface.

[0066] R _max of the rake face of the cutting edge was 0.2 [mu] m. FIG. 2 shows the main part of the diamond cutting tool thus obtained.

The rake face 15 of the cutting edge 12 is made flat, and most of it is constituted by the (311) face.

In the third embodiment, an example in which the diamond crystal growth ending surface side is mirror-polished after the diamond deposition step has been described. In such a mirror-polishing step, the diamond cutting edge is formed of a cemented carbide (SPG422). ) May be performed after brazing to the base metal. After the diamond deposition step, the side of the diamond crystal growth end surface is mirror-polished, and the cutting edge of the diamond is cemented carbide (S
After brazing to the base metal of PG422), the diamond crystal growth end surface side may be mirror-polished.

Example 4 Under the same conditions as in Example 3, a 300 μm thick
m of polycrystalline diamond was formed. Next, the polycrystalline diamond on the Si substrate was cut into a size and shape required for the tool by a laser. Next, a metallized layer is formed on the surface of the Si substrate on which the diamond is formed, on the surface opposite to the surface on which the diamond is formed, in the same manner as in Example 1, and then the silver of the base metal of the cemented carbide (SPG422) is formed. Brazing was performed using a braze.

After brazing the Si substrate on which the diamond was formed to the base metal, the diamond on the Si substrate was mirror-polished to make R _max ≦ 0.2 μm or less. FIG. 3 shows a main part of the diamond cutting tool thus obtained. The Si base material 27 is brazed to a predetermined region of the base metal 21 made of cemented carbide (SPG422) via the brazing layer 23 and the metallized layer 24. The rake face 25 of the diamond cutting edge 22 on the Si base material 27 is flattened, and most of the rake face 25 is constituted by the (311) face. In the fourth embodiment, an example is shown in which, after the brazing step of brazing the Si base material 27 on which the diamond is formed to the base metal 21, the crystal growth end surface side of the diamond is mirror-polished. The mirror polishing process is
This may be performed after the diamond deposition step of depositing diamond on the Si base material 27. After the diamond deposition step, the diamond crystal growth end surface may be mirror-polished, and after the brazing step, the diamond crystal growth end surface may be mirror-polished.

Example 5 Referring to FIG. 4, polycrystalline diamond having a thickness of 300 μm was formed on a mirror surface of a Si base under the same conditions as in Example 1. Next, the polycrystalline diamond on the Si substrate was cut into a size and shape required for the tool by a laser. Next, Si
Without separating or removing the base material 37, Ti having a thickness of 1 μm and a thickness of 2
After sequentially laminating Ni with a thickness of μm, a cemented carbide (SPG42)
The base metal 31 of 2) was vacuum brazed using a silver braze (see FIG. 4A). Next, the Si substrate 37 was dissolved and removed with hydrofluoric acid to produce a diamond cutting tool. In the diamond cutting edge 32 from which the Si substrate 37 was dissolved and removed, the surface Ss that was in contact with the Si substrate 37 was lightly mirror-polished to form a rake surface 35. R _{max of the} rake face 35 was 0.1 μm. FIG. 4B shows a main part of the tool according to the fifth embodiment. Referring to FIG. 4B, a diamond cutting edge 32 is fixed to a predetermined region of a base metal 31 made of a superalloy via a brazing layer 33 and a metallized layer. The rake face 35 of the cutting edge 32 is (31
1) It is occupied by the face. A flank 36 is formed on the end face of the cutting edge 32.

Comparative Example Using a device similar to that used in Example 1, a hot filament CVD method was used to form a film having a thickness of 200
A μm polycrystalline diamond was formed.

Source gas (flow rate): CH ₄ / H ₂ = 3%,
Total flow rate 1000 cc / min Gas pressure: 80 Torr Filament temperature: 2150 ° C. Filament-substrate distance: 6 mm Substrate temperature: 920 ° C. Next, the polycrystalline diamond on the Si base material is cut by laser into a size and shape required for a tool. After that, S
The i-base was dissolved and removed to obtain a diamond cutting edge.

X-ray diffraction was performed on the obtained diamond cutting edge, and the peak intensity ratio I (220) / I
(311) was 20, indicating that the (220) plane was strongly oriented. Further, according to the rocking curve of the (220) plane, the FWHM value was 10 °. Other peak intensity ratios I (111) / I (311) were 5, peak intensity ratios I (331) to I (311) were 6, and the (400) plane was not observed yet.

The cutting edge thus obtained was brazed to a cemented carbide base in the same manner as in Example 1.

In order to evaluate the performance of the diamond cutting tools manufactured in Examples 1 to 5 and Comparative Example, a cutting test (turning) was performed under the following cutting conditions.

Work material: A390 Cutting speed: 800 m / min Feed: 0.12 mm / rev Depth of cut: 0.5 mm As a result of a continuous cutting test for about 30 minutes, the maximum flank wear width of each sample (V _{B max} : μm) ) Is the sample of Example 1:
48 μm, Example 2 sample: 78 μm, Example 3 sample: 45 μm, Example 4 sample: 45 μm, and Example 5 sample: 48 μm. The examples according to the present invention showed good characteristics.

On the other hand, in the comparative example, when a continuous cutting test was performed for one minute, a large defect of 100 μm or more occurred.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically showing a diamond cutting tool manufactured in Example 1.

FIG. 2 is a cross-sectional view schematically illustrating a diamond cutting tool manufactured in Example 3.

FIG. 3 is a cross-sectional view schematically illustrating a diamond cutting tool manufactured in Example 4.

FIG. 4 is a drawing schematically showing a manufacturing process of Example 5.

[Explanation of symbols]

 1, 11, 21, 31 Base metal 2, 12, 22, 32 Cutting edge 3, 13, 23, 33 Brazing layer 4, 14, 24, 34 Metallized layer 5, 15, 25, 35 Rake face 6, 16, 26 , 36 flank 37 Si base Se end of crystal growth Ss surface in contact with base

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Naoji Fujimori 1-1-1, Koyokita, Itami-shi, Itami-shi, Hyogo Itami Works, Sumitomo Electric Industries, Ltd. (56) References JP-A-62-107068 (JP, A (58) Fields surveyed (Int. Cl. ⁷ , DB name) C30B 29/04 B23B 27/20 B23P 15/28 C23C 16/26-16/27

Claims (5)

(57) [Claims] 1. A diamond cutting tool comprising a cutting edge made of a diamond material synthesized in a vapor phase, wherein a main diamond crystal surface forming a rake face of the cutting edge is a (311) plane. tool. 2. A method for producing a diamond cutting tool comprising a cutting edge made of a diamond material synthesized in a vapor phase, comprising: preparing a base material having a surface-finished surface on which diamond is to be deposited; Depositing diamond on the surface by vapor phase synthesis so that the (311) plane is oriented substantially parallel to the surface; separating or removing the base material on which diamond is deposited to remove diamond material as the cutting edge; A method for manufacturing a diamond cutting tool, comprising: a step of obtaining; and a step of brazing the diamond material to a tool base using a surface of the diamond material that has been in contact with the base material as a rake face of the cutting edge. 3. A method for producing a diamond cutting tool comprising a cutting edge made of a diamond material synthesized in a gas phase, comprising: preparing a base material having a surface-finished surface on which diamond is to be deposited; Depositing diamond on the surface by vapor phase synthesis so that the (311) plane is oriented substantially parallel to the surface; separating or removing the base material on which diamond is deposited to remove diamond material as the cutting edge; And a step of brazing the diamond material to a tool base with the end face of crystal growth of the diamond material being a rake face of a cutting edge, further comprising, after the diamond deposition step or the brazing step, Mirror polishing the crystal growth end surface side of diamond synthesized by vapor phase. Manufacturing method. 4. A method for producing a diamond cutting tool comprising a cutting edge made of a diamond material synthesized in a gas phase, comprising: preparing a base material having a surface-finished surface on which diamond is to be deposited; A step of depositing diamond on the surface by vapor phase synthesis so that the (311) plane is oriented substantially parallel to the surface, and forming the rake face of the cutting edge by using the diamond-deposited substrate by the diamond deposition step. A step of brazing the tool base such that a main diamond crystal plane is a (311) plane, further comprising, after the diamond deposition step or the brazing step, a crystal growth end surface side of diamond synthesized by vapor phase synthesis. And a step of mirror-polishing the diamond cutting tool. 5. A method for manufacturing a diamond cutting tool comprising a cutting edge made of a diamond material synthesized in a vapor phase, comprising: preparing a base material having a surface-finished surface on which diamond is to be deposited; A step of depositing diamond on the surface by vapor phase synthesis so that the (311) plane is oriented substantially parallel to the surface, and a step of terminating the diamond crystal growth end surface of the base material on which diamond is deposited in the diamond deposition step. A method for producing a diamond cutting tool, comprising: a step of brazing to a tool base; and a step of separating or removing the base so that a main diamond crystal plane constituting a rake face of the cutting edge is a (311) plane. .