JPH07196379A - Tool for brazing synthetic diamond in gas phase and its production - Google Patents

Abstract

PURPOSE:To obtain a brazed tool excellent in strength and heat resistance by brazing a diamond film member through a silicon brazing material, the diamond film member being formed at the action part of a base material for the tool by a gaseous synthetic method. CONSTITUTION:A brazed tool is produced by brazing a diamond film member at the action part of a tool base material comprising a cemented carbide or ceramic through a brazing material comprising silicon or a silicon alloy, the diamond film member being preliminarily formed in a shape corresponding to the outer shape of the action part by a gaseous phase synthetic method. The thickness of the diamond film member is preferably approximately 0.05-1mm. The thickness is controlled to >=0.05mm, because the flank wear width of the tool usually reaches >=0.05mm. The thickness is also controlled to <=1mm, because the performance of the tool is not changed even when the thickness is larger than the 1mm, and because the large thickness requires only a long time for forming the film and does not any advantage.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vapor phase synthetic diamond brazing tool in which a diamond film member synthesized by a vapor phase synthesis method is brazed to an active portion of a tool base material, and a method for producing the same, and particularly when the tool is used. The present invention relates to a diamond brazing tool having excellent strength and heat resistance, which prevents softening and melting of the brazing material in the above, and a useful method for producing such a tool. The present invention also relates to a vapor phase synthetic diamond brazing tool having excellent fracture resistance and wear resistance, which is suitable for cutting non-ferrous metals and ceramic materials, and a useful method for producing such a tool. is there.

[0002]

2. Description of the Related Art Since diamond has the highest hardness among materials and high thermal conductivity, it has been actively applied and developed to cutting tools and wear resistant tools in recent years. In particular, a sintered diamond produced by sintering fine diamond powder at high temperature and high pressure is widely used as a cutting tool for non-ferrous metals. However, the diamond sintered body contains about 5 to 10% of Co as a sintering aid, and since this Co exists in the grain boundary of diamond and lowers the grain boundary strength, such a diamond sintered body is used. Even if the bonded body is applied as a cutting tool, there is a problem that chipping or chipping of the cutting edge is likely to occur during cutting.

On the other hand, since the method of vapor phase synthesis of diamond was established, it could be applied to tools with complicated shapes easily and inexpensively. Development of tools in which the surface of the tool base material is coated with a diamond film is also active. However, the vapor phase synthesized polycrystalline diamond film has high strength,
Although it has excellent characteristics as a tool member with high thermal conductivity, it has a drawback that it easily peels off during cutting, even if it is coated on a cutting tool, for example, because the film has large internal stress and low adhesion to the tool base material. However, it cannot be said that sufficient performance is obtained.

Therefore, as a method for improving the adhesion of a vapor phase synthesized polycrystalline diamond film, Japanese Patent Laid-Open No. 1-212766 has been proposed.
No. 1 and No. 1-212767 are also proposed. In these techniques, a polycrystalline diamond film is bent on a substrate by a vapor phase synthesis method, and a melting point of a tool base material is 700 ° C. so that a joining surface side of the polycrystalline diamond and the substrate becomes a rake surface side of the tool. From 1300 ° C. to 1300 ° C., and removing the substrate from the polycrystalline diamond before or after brazing. Since the tool produced in this way (hereinafter referred to as vapor phase synthetic diamond brazing tool) has a polycrystalline diamond film attached to the tool base material by a brazing material, the adhesion between the tool base material and the diamond film is Good and as mentioned above 10
Since the diamond tool is composed of nearly 0%, it exhibits excellent performance in strength and wear resistance with respect to a sintered diamond tool containing a metal binder.

[0005]

The vapor phase synthetic diamond brazing tool described above has excellent advantages that cannot be obtained by conventional tools. Since it is brazed to the tool base material, under severe cutting conditions where the temperature of the cutting edge is extremely high, the heat generated by cutting is easily transmitted to the brazing material layer, and the temperature of the brazing material layer rises. Since the brazing filler metal used is an alloy, when the temperature rises to more than half the melting point of the brazing filler metal, the strength of the brazing filler metal layer decreases, causing the strength of the diamond tool to decrease, resulting in large chipping or cracking of the diamond cutting edge. There is a problem. For example, Ag-Cu
-Ti-based brazing material (melting point about 800 ° C) has a temperature of 500
When the temperature is above ℃, the brazing material strength is extremely reduced.

On the other hand, the vapor phase synthetic diamond brazing tool as described above also has a problem that the cutting edge is broken under severe cutting conditions such that a high load or impact is applied to the cutting edge during cutting. It is considered that one of the causes of such a cutting edge defect is that the vapor-phase synthetic diamond has a columnar structure. That is, in the film formation process of vapor-phase synthetic diamond, for example, as shown in FIG. 1, first, a diamond nucleus 2 is formed on a substrate 1 at the initial stage of diamond synthesis [FIG.
(A)], and then these diamond nuclei grow into diamond grains 3 and gradually cover the entire surface of the substrate 1 [Fig.
(B)], the diamond grains 3 have different growth rates,
The growth of grains having a high growth rate becomes dominant, and the diamond grains 3 become coarse and form columnar structures 4 [FIG.
(C)]. When the columnar structure 4 as shown in FIG. 1 (c) is formed, the grain boundaries are increased accordingly and the grain boundary defects are also increased. As a result, it is considered that the toughness of diamond is lowered and the diamond is likely to be damaged. As is generally said for ceramic materials, making a fine grain structure is expected to be an effective means of improving toughness and fracture resistance, but diamond grain growth Each grain is epitaxially grown, and grains are grown until secondary nuclei are generated on the grain surface. The secondary nuclei do not occur unless the diamond grains grow to some extent, and the frequency of occurrence is low, so that it is very difficult to form a diamond grain structure.

[0007] As a means for improving such fracture resistance,
Highly purified diamond (for example, Japanese Patent Laid-Open No. 2-
232106), a method for strengthening the grain boundary bonding of diamond (for example, JP-A-3-103395), and a method in which impurities are added to diamond (for example, JP-A-3-10).
3397), those in which the film quality is changed in the film thickness direction of diamond (for example, Japanese Patent Application Laid-Open Nos. 4-240004 and 4-223807) have been proposed. However, in the technologies proposed so far,
Since the cutting edge of the tool cutting edge is used, the cross section of the diamond film, that is, the columnar structure is exposed at the cutting edge, and there is a problem that the cutting edge is damaged when a high load or impact is applied to the cutting edge during cutting.

The present invention has been made in view of the above circumstances, and its first purpose is to prevent softening and melting of a brazing filler metal even under severe cutting conditions, and to improve strength and heat resistance. Vapor-phase synthetic diamond brazing tool with improved durability,
And to provide a useful method for producing such vapor phase synthetic diamond brazing tools. Second of the present invention
The purpose is to provide a vapor phase synthetic diamond brazing tool with improved toughness and significantly improved fracture resistance of the cutting edge portion, and a useful method for producing such a vapor phase synthetic diamond brazing tool. There is.

[0009]

The vapor-phase synthetic diamond brazing tool of the present invention which has achieved the first object is:
A diamond film member formed in advance in a shape corresponding to the external shape of the tool base material made of a cemented carbide or ceramics in a shape corresponding to the outer shape of the portion by means of a vapor phase synthesis method has a brazing material made of silicon or a silicon alloy. It has the gist of being brazed.

Such a vapor phase synthetic diamond brazing tool is obtained by vapor phase synthesizing a diamond film member on a brazing material made of silicon or a silicon alloy, and then applying it to a working portion on a tool base material made of a cemented carbide or ceramic. It can be manufactured by arranging so that the brazing material side is in contact with the tool base material, subsequently melting the brazing material and then cooling and solidifying the brazing material to braze the diamond film member onto the tool base material.

In the vapor phase synthetic diamond brazing tool as described above, after the diamond film member is synthesized on the substrate by the vapor phase synthesis method, the bonding surface side of the diamond film member and the substrate is cemented carbide or ceramics. Is arranged so as to be on the rake face side of the tool base material made of, and a brazing material made of silicon or a silicon alloy is arranged between the tool base material and the diamond film member, and the brazing material is melted and then cooled. It can also be manufactured by a method such as solidifying and brazing the diamond film member on a tool base material, and removing the substrate before or after brazing.

The vapor-phase synthetic diamond brazing tool of the present invention which has achieved the second object is that the active portion of the tool base material made of cemented carbide or ceramics is previously formed by the vapor-phase synthesis method. The diamond film member formed in a shape corresponding to the outer shape is brazed through a brazing material made of silicon or a silicon alloy, and at least the exposed portion of the diamond film member is covered with a vapor phase synthetic diamond film. It has the gist in that it has been done.

In such a vapor phase synthetic diamond brazing tool, after the diamond film member is synthesized on the substrate by the vapor phase synthesis method, the bonding surface side of the diamond film member and the substrate is made of cemented carbide or ceramics. While arranging so as to be on the rake face side of the tool base material, between the tool base material and the diamond film member, a brazing material made of silicon or a silicon alloy is disposed, and the brazing material is melted and then cooled and solidified. The diamond-based polycrystalline thin film member is brazed on a tool base material, and the substrate is removed before or after brazing, and after performing the cutting process of the diamond film member, at least the diamond film member It can be manufactured by coating the exposed portion with a vapor phase synthetic diamond film.

[0014]

[Function] Since diamond has a thermal conductivity as high as 5 times that of copper, when the diamond film is brazed to the tool base metal, the heat generated at the cutting edge of the tool is easily transferred to the brazing metal. Will be done. Therefore, as mentioned above,
Under severe cutting conditions, the brazing filler metal is softened by high temperatures, and when it is worse, melting occurs, causing the diamond film member that was fixed by the brazing filler metal to crack and chip due to high cutting stress, or to come off from the tool base metal. Occurs.

Therefore, the present inventors have studied from various angles in order to solve the above-mentioned inconveniences and to realize a diamond brazing tool having improved heat resistance and further improved strength. As a result, if a brazing material made of silicon or a silicon alloy is used as the brazing material, softening or melting of the brazing material does not occur even at high temperatures under severe cutting conditions,
The inventors have found that the strength and heat resistance of a vapor phase synthetic diamond brazing tool are significantly improved, and have completed the present invention.

In the present invention, as described above, it is important to use a brazing material made of silicon or a silicon alloy as a brazing material for brazing the diamond film member to the working portion of the base material. A conventional vapor phase synthetic diamond brazing tool is disclosed in Japanese Patent Application Laid-Open No. 1-212766.
No. 1-221767, the melting point of the brazing filler metal is 700 to 1300 ° C. and Au, Ag, Cu,
Metal brazing materials containing Ti, Ta, etc. are used. However, since these metal brazing materials have low melting points, softening or melting of the brazing material occurs under severe cutting conditions. On the other hand, silicon used as a brazing filler metal in the present invention has a high melting point of 1420 ° C. and is a covalent bond crystal. Is less likely to decrease. Also in the case of silicon alloys, the melting point is higher than 1300 ° C., and the high temperature strength is very high for forming an intermetallic compound, so that strength does not decrease unless the temperature exceeds 1300 ° C. For these reasons, the high temperature strength is superior to the conventional metal brazing material, but silicon has a thermal expansion coefficient close to that of diamond, and the diamond film member is brazed by melting and cooling and solidifying the silicon. However, almost no thermal stress occurs. For these reasons, the vapor phase synthetic diamond brazing tool of the present invention can be used even under severe cutting conditions.

The silicon alloy used as the brazing filler metal in the present invention preferably contains at least one metal selected from the 4A, 5A and 6A elements of the periodic table. That is, even if silicon itself is used, it reacts with diamond at a high temperature to form a carbide at the interface between the diamond and the brazing filler metal and firmly bond the diamond.
Group A, 5A, and 6A elements easily react with diamond at high temperatures to form carbides, which enhances the effect of strongly bonding with diamond. Further, the bonding strength between the diamond film and the tool base material by brazing also depends on the thickness of the brazing material, and the thickness of the brazing material is preferably 0.5 to 100 μm. That is, when the thickness of the brazing filler metal is less than 0.5 μm, the brazing tends to be non-uniform and strong brazing cannot be performed. On the other hand, when the brazing filler metal is thicker than 100 μm, the strength at high temperature, particularly at 1200 ° C. The strength of the is extremely reduced.

The thickness of the diamond film member is 0.05
It is preferably about 1 mm. The reason why the width is 0.05 mm or more is that the flank wear width of the tool is usually 0.05 mm or more. The reason why the thickness is 1 mm or less is that even if the thickness is larger than that, the tool performance does not change, and it takes time to form the film, which is not advantageous.

The tool base material used in the present invention is cemented carbide or ceramics, but among the ceramics, silicon carbide, silicon nitride or sialon is particularly desirable. That is, silicon or a silicon alloy is strongly bonded to various ceramics. Among them, silicon carbide, silicon nitride or sialon has a coefficient of thermal expansion very close to that of diamond, silicon, or a silicon alloy. Thermal stress is less likely to occur even if the cutting edge temperature rises due to cutting.

In producing the above-described vapor-phase synthetic diamond brazing tool, as described above, the diamond film member is vapor-phase-synthesized on the brazing material made of silicon or silicon alloy, and then cemented carbide or ceramic. By placing the brazing filler metal side so that the brazing filler metal side is in contact with the tool base metal, and subsequently melting and brazing the brazing filler metal to cool and solidify the diamond film member on the tool base metal. It can be manufactured. In this case, the diamond growth surface side is the tool rake surface side. The surface roughness of the diamond film depends on the film thickness, but the surface roughness is very rough because the crystal grain size is composed of grains of several μm to several tens of μm. When the rake surface of the tool is rough, the work material is welded to the rake surface at the time of cutting to form the constituent cutting edge, and thus the surface of the work material becomes very rough. Therefore, although it can be used in rough cutting, it cannot be used in finish cutting, and it is necessary to improve the rake surface roughness. In order to prevent welding from occurring, it is desirable that the surface roughness R _max be 0.3 μm or less. As a method for smoothing the rake face, the rake face may be polished with a skiff disk or the like.

In the vapor phase synthetic diamond brazing tool as described above, after the diamond film is synthesized on the substrate by the vapor phase synthesis method, the bonding surface side of the diamond film and the substrate is made of cemented carbide or ceramics. The diamond is placed so as to be on the rake face side of the tool base material, and a brazing material made of silicon or a silicon alloy is placed between the tool base material and the diamond film member, and the diamond is melted and then solidified by cooling. It can also be obtained by brazing a film member on a tool base material and removing the substrate before or after brazing. According to this method, the surface roughness of the substrate is R _max of 0.3 μm or less. If this is done, it can be transferred to obtain a vapor phase synthetic diamond tool having a rake surface roughness of R _{max of} 0.3 μm or less.

The step of melting and then cooling and solidifying the silicon or silicon alloy is preferably performed in a vacuum or in an inert gas atmosphere. This is because when it is performed in the air, silicon or silicon alloy is oxidized and diamond is also oxidized to be carbon dioxide gas. Examples of the inert gas used at this time include helium, neon, argon, krypton, xenon, nitrogen and hydrogen.

By the way, in the conventional vapor phase synthetic diamond brazing tool, since the toughness may be poor and the cutting edge portion may be damaged, as described above, the present inventors have found that the vapor phase synthetic diamond brazing tool is used. Further studies have been conducted from the viewpoint of increasing the toughness of the mounting tool and improving the fracture resistance of the cutting edge. As a result, after the diamond film member is brazed to the working portion of the base material as a brazing material of silicon or silicon alloy to produce the vapor phase synthetic diamond brazing tool of the present invention as described above, at least the brazing tool The exposed part of the diamond film member is further covered with a vapor phase synthetic diamond film, it is found that it is possible to enhance the toughness of the vapor phase synthetic diamond brazing tool and improve the fracture resistance of the cutting edge portion. The second purpose was achieved.

As shown in FIG. 2, when the diamond film member 5 is still brazed 7 to the tool base material 6, the cross section of the diamond film member 5 is exposed on the flank side of the tool cutting edge (lower side in FIG. 2). Therefore, it is considered that the cutting edge is likely to be damaged by the main component force which is the force from the rake face side (lower side in FIG. 2) during cutting. On the other hand, when the diamond film member 5 is brazed and then at least the exposed portion of the diamond film member 5 is further covered with the vapor phase synthetic diamond film, as shown in FIG. Since the diamond film 8 having a columnar structure is formed so as to extend in the direction perpendicular to the surface of the, the main component force received during cutting is almost perpendicular to the columnar direction of the columnar structure of the diamond film 8 formed on the tool flank. Will join. In the columnar structure, the grain boundaries slip and are weak against a force applied in the columnar direction, but are very strong against a force applied almost perpendicularly to the columnar direction.

In the vapor phase synthetic diamond brazing tool of the present invention as described above, the surface roughness of the work material is not so important particularly in the rough machining in which a high load or impact is applied to the cutting edge during cutting. The surface roughness of the diamond film 8 to be coated does not matter so much and a diamond film having a rough surface may be coated, but when used for finishing, the surface of the tool, especially the surface near the cutting edge is smooth. Sex is required. Especially when the surface roughness of the rake face of the tool is rough,
When the work material is welded on the rake face and a part of it drops off and sticks to the surface of the work material, or when the weld material forms the constituent cutting edge, the welding material becomes the cutting edge, so the work material Surface roughness is reduced. Therefore, it is necessary to prevent welding, but for that purpose, the roughness of the rake face is preferably 0.3 μm or less in terms of R _max . The roughness of the rake face to the 0.3μm or less in R _max is the rake face after as described above coating is possible by grinding in scaife panels, etc., diamonds are very abrasive to have the highest hardness Takes time. Therefore, as a result of diligent efforts, the inventors of the present invention have determined that the surface roughness of the rake face without polishing is 0.3 μ at R _max .
I thought of making it less than m. That is, a vapor-phase synthetic diamond usually has a rough surface, but under special synthesis conditions, the (100) crystal plane of diamond is
It is possible to orient the plane perpendicular to the film thickness direction and cover the surface of the diamond film with a very smooth (100) plane.
In addition, the surface roughness of the film can be 0.3 μm or less in R _max .

In the vapor phase synthetic diamond brazing tool coated with a diamond film, the surface roughness of the rake face side of the diamond film member to be brazed first is also R _max of 0.
It is preferably 3 μm or less. This means that if the surface roughness of the diamond film member is rougher than 0.3 μm in R _max ,
This is because even if the surface is coated with a (100) oriented diamond film, it becomes difficult to reduce the surface roughness of the coated diamond film to R _max of 0.3 μm or less.

In the vapor phase synthetic diamond brazing tool of the present invention, it is preferable that the diamond film covering the diamond film member has an average film thickness of 1 to 200 μm, and the diamond film member and the coated diamond film on the rake face side. The total film thickness is preferably 50 to 1000 μm (1 mm). The preferable total film thickness is set in the above range because the flank wear width of the tool is often 50 μm or more, and even if the tool thickness is more than 1 mm, the tool performance does not substantially change. This is because it takes time and there is no advantage. Further, if the average thickness of the diamond film coating the diamond film member is less than 1 μm, the effect of coating with the diamond film is not exerted so much that the cutting edge is broken, and even if it exceeds 200 μm, the tool performance is substantially reduced. This is because there is no change, and it takes time to form the film, which is not advantageous.

Also in the vapor phase synthetic diamond having a structure coated with a diamond film, the thickness of the brazing material used is preferably 0.5 to 100 μm for the same reason as above. The silicon alloy used at this time is preferably a group 4A, 5A, or 6A element of the periodic table from which Cr is removed. This is because Cr has a high vapor pressure and can bond diamonds, but it vaporizes when the diamonds are subsequently coated, which hinders the formation of diamonds.

In producing a vapor phase synthetic diamond brazing tool coated with a diamond film, a vapor phase synthetic diamond brazing tool brazing a diamond film member by the above-mentioned method is produced, and then a diamond film is further formed. After performing the cutting process on the member, at least the exposed member of the diamond film member may be covered with the vapor phase synthetic diamond film.

In the present invention, the method for synthesizing the diamond film member, the diamond film to be coated, etc. is not particularly limited, but, for example, the raw material gases of hydrogen and hydrocarbon are thermionic emission material or microwave non-polar discharge A chemical vapor deposition method (CVD method) that is excited and decomposed by, for example, is used.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the following Examples are not of a nature limiting the present invention, and any design changes may be made according to the purpose of the invention. It is included in the technical scope.

[0032]

【Example】

Example 1 By a microwave plasma CVD method, as shown in FIG.
S having a surface roughness R _max of 0.04 μm and a thickness of 150 μm
Polycrystalline diamond 10 was synthesized on i substrate 12 for 16 hours under the following conditions. At this time, the thickness of the polycrystalline diamond was 120 μm. Raw material gas (flow rate): H ₂ 100 sccm CH ₄ 1 sccm Pressure: ₄₀ torr Substrate temperature: 850 ° C. Microwave output: 1 kw

After cutting three pieces of this film into the shape of a tool edge with a YAG laser (FIG. 5), the two pieces are immersed in an aqueous sodium hydroxide solution at 90 ° C. to dissolve and remove the Si substrate 12 to remove only the diamond 10. A diamond film member 5 was obtained (FIG. 6). Next, one of the diamond film members from which the Si substrate 12 has been removed is treated with Ag-Cu-Ti alloy brazing material so that the original Si substrate side becomes the rake face side of the tool.
A tool A was produced by brazing on a PGN120308-shaped cemented carbide chip and performing blade processing. At this time, the thickness of the brazing material layer is 40 μm, and the roughness of the surface of the diamond member corresponding to the chip rake surface is Si substrate 1.
A surface roughness of 2 is transferred, and R _max is 0.04 μm
Met.

Regarding the diamond film member from which the other Si substrate 12 has been removed, as shown in FIG.
Diamond film member 5 with 0 μm silicon powder 14
And SPGN120308-shaped cemented carbide chips 15 were inserted into a heating furnace having a vacuum degree of 10 ^-6 torr, the temperature was raised to 1450 ° C., and the diamond film members were joined by slow cooling. At this time, the diamond film member 5 has the original S
The i-board 12 was brazed so that the side of the i-board 12 was the rake face of the tool. After the brazing, a blade-making process was performed to produce a tool B. When the thickness of the brazing material layer of this tool was examined, it was 30μ
It was m. The surface roughness of the diamond used as the chip rake face was 0.04 μm in R _max .

On the other hand, with respect to the diamond 10 in which the Si substrate 12 is not removed by melting, the Si substrate 12 side is SPG
N120308-shaped cemented carbide tip 15 was placed in contact with it, and it was inserted into a heating furnace with a vacuum degree of 10 ^-6 torr. After raising the temperature to 1450 ° C, it was slowly cooled and brazed with diamond, and then bladed. Processing was performed to produce a tool C.
When the thickness of the silicon brazing material layer was examined, it was 93 μm. Further, the surface roughness of the diamond to be the rake face of the chip was R _max of 2.2 μm. The appearance of the tool manufactured as described above is shown in FIG. In the figure, 16 is a brazing material layer.

[0036]

[Table 1]

Next, regarding these chips, A1-1
Cutting speed V: 400 m / m using a round bar of 6% Si alloy
in, depth of cut t: 0.25 mm, feed rate f: 0.1
mm / rev loose conditions and cutting speed V: 600 m / m
in, cut t: 2 mm, feed rate f: 0.4 mm /
Dry continuous cutting was performed for 60 minutes in the longitudinal direction of the outer periphery under severe rev conditions. The results are shown in Table 2. Under the loose cutting conditions, no chipping of the cutting edge or minute chipping was observed in all the chips, only the chip C having a rough rake surface was welded to the rake surface, and the surface roughness R _max was 4.6 μm. It became coarse.
On the other hand, chips A and B having a small surface roughness did not cause welding at all, and the roughness of the surface to be machined was as good as 2.1 μm in R _max .
On the other hand, under severe cutting conditions, in the chip A, wax flowed out within 5 minutes of cutting, and a breakage of the cutting edge was observed. On the other hand, the chips B and C showed good cutting performance without any breakage of the cutting edge or fine chipping even after cutting for 60 minutes.

[0038]

[Table 2]

Example 2 By a hot filament CVD method using a tantalum wire having a diameter of 0.5 mm, various times of various times as shown in Table 3 below were obtained on a Mo substrate having various surface roughness under the following conditions. Crystalline diamond was deposited. Raw material gas: H ₂ 100 sccm Ethanol 4 sccm Pressure: 200 torr Filament temperature: 2200 ° C. Substrate temperature: 850 ° C. Filament-substrate distance: 6 mm

Thereafter, the diamond-precipitated Mo plate was immersed in aqua regia to dissolve and remove Mo, and only diamond was obtained. Next, after cutting the diamond by YAG laser, on the cemented carbide chips and various ceramic chips (shape: SP
GN120304) was brazed with silicon or a silicon alloy and subjected to blade processing. Table 3 shows the diamond film thickness, rake surface roughness (R _max ), the type of silicon or silicon alloy used as the brazing material, the brazing material layer thickness,
The results of analysis of the interface between diamond and silicon or silicon alloy by Auger electron spectroscopy, such as brazing conditions, are shown.

[0041]

[Table 3]

For these chips, A1-16% S
Cutting speed for i alloy as in Example 1 is 600 m / mi.
n, depth of cut: 2 mm, feed rate: 0.4 mm / rev
The test was conducted under the following cutting conditions. The results are shown in Table 4. As is clear from Table 4, the tool according to the present invention maintained a sharp cutting edge without any damage even after cutting for 60 minutes. On the other hand, in Comparative Example No. No. 6 has a large flank wear width, In No. 7, the diamond and silicon alloy layers were oxidized and could not be joined.

[0043]

[Table 4] Example 3 The surface roughness was R _max by the microwave plasma CVD method.
Was subjected to vapor phase synthesis on a 0.10 μm Si substrate for 20 hours under the following conditions to obtain a polycrystalline diamond film having a thickness of 120 μm. Raw material gas (flow rate): H ₂ 200 cc / min CH _{4 2} cc / min Pressure: ₄₀ torr Substrate temperature: 900 ° C. Microwave output: 1 kw

Two pieces of this film were cut into the shape of a tool blade with a YAG laser and then immersed in an aqueous solution of sodium hydroxide at 60 ° C. to dissolve and remove the Si substrate to obtain a diamond film member composed of only diamond. As for the roughness of the diamond surface, the surface roughness of the Si substrate is transferred, and R _max is 0.
It was 11 μm.

Furthermore, one polycrystalline diamond and SPG were used so that the original substrate side became the rake face.
Insert silicon into N120308-shaped cemented carbide chips and insert into a heating furnace with a vacuum degree of 10 ^-5 torr and set the temperature to 1
The temperature was raised to 450 ° C. to melt the silicon and then slowly cooled to braze the diamond. After brazing, the blade was worked to prepare a tool D.

On the other hand, using the remaining polycrystalline diamond film, a polycrystalline diamond tip is produced in the same manner as described above, and then microwave plasma CV is applied to the surface of the tip.
The diamond surface of the chip is formed to a thickness of about 12 μm by forming a diamond film for 2 hours by the method D under the same conditions as described above.
A polycrystalline diamond tip E was produced by coating with m diamond. The surface roughness of the rake face of the tip E is R _max
Was 1.0 μm. Also, both chips D and E
The brazing material layer had a thickness of about 30 μm.

Next, for these chips, the work material A
Cutting speed: 400m using a round bar of 1-20% Si alloy
/ Min, depth of cut: 2 mm, feed rate: 0.4 mm /
Dry continuous cutting was performed under the condition of rev, and the cutting performance was evaluated. As a result, the chip of D was chipped 5 minutes after cutting,
Regarding the tip of E, no breakage of the cutting edge was observed even after 90 minutes of cutting.

Example 4 In the same manner as in Example 3, the surface roughness R _max was 0.04 μm.
Polycrystalline diamond was deposited on two types of Si substrates of m and 0.7 μm for 20 hours to obtain a diamond film having a thickness of 120 μm. Then, with respect to each substrate on which the diamond was formed, each of the two substrates was cut into a tool edge shape by a YAG laser and immersed in a sodium hydroxide aqueous solution at 60 ° C. to dissolve and remove the Si substrate to remove only the polycrystalline diamond film. Obtained. The surface roughness of the original silicon substrate side of the diamond at this time, the surface roughness of silicon is transferred,
It was the same value as the surface roughness of silicon.

Next, with these four polycrystalline diamond films, silicon was sandwiched between the diamond and the silicon nitride chip so that the original substrate surface side became the rake surface, and the temperature was 1450.
The temperature was raised to 0 ° C. to melt the silicon, followed by gradual cooling to solidify the silicon to braze the diamond and the silicon nitride chips, and perform edge cutting to prepare four polycrystalline diamond chips. The chip shape at this time is SPGN120.
It was set to 304. In addition, the silicon bond has a vacuum degree of 10 ^-6 t.
It was carried out in a high vacuum of orr.

Of these chips, the rake surface roughness is R
_max 0.04μm tip (chip a) and 0.7μm
One chip (chip b) is taken out, and microwave plasma CVD is performed on the surface of these chips under the following conditions.
To form a diamond film. When the surface of the diamond film further coated on the surface of the brazed diamond film was observed with a scanning electron microscope, the surface of the diamond crystal plane (10
It was observed that the (0) plane was oriented almost perpendicular to the film thickness direction. Further, when the rake surface roughness of the tip coated with these diamond films was measured, the surface roughness of the diamond film coated on the diamond of the tip a was R _max of 0.15 μm, and the diamond on the tip b was coated. The surface roughness R _max of the diamond film was 0.8 μm. Hereinafter, these diamond-coated chips will be referred to as chip a1 and chip b1, respectively. Raw material gas: H ₂ 185 cc / min CH ₄ 10 cc / min CO 5 cc / min Pressure: 30 torr Microwave output: 1.3 kw Substrate temperature: 700 ° C. Synthesis time: 7 hours Film thickness: 15 μm

Diamond was deposited for 2 hours on the surfaces of the remaining chips a and b under the same conditions as in Example 3. The diamond film thickness at this time was 12 μm. When the rake surface roughness of these chips was measured, the surface of the coated diamond was rough, and R _max was 1.0 μm for chip a and R _max was 1.7 μm for chip b. Among them, as for the chip in which the chip a was coated with diamond, the rake face of the chip was polished using a skiving machine to prepare a chip a2 having a rake face roughness of R _max of 0.05 μm. In addition, a chip in which the chip b is coated with diamond is hereinafter referred to as the chip b2.
I will call it.

For these four chips, the work material A
Cutting speed: 400 using a round bar of 1-16% Si alloy
m / min, depth of cut: 0.2 mm, feed: 0.1 mm
Dry cutting was performed under the condition of / rev, and the cutting performance was evaluated. The results are shown in Table 5. As is clear from Table 5, the cutting edges were not found for all the chips, but for the chips b1 and b2 with rough rake faces, welding was generated on the rake faces and the roughness of the work surface was rough. On the other hand, the chips a1 and a2 having a smooth rake surface did not cause welding, and a good work surface was obtained.

[0053]

[Table 5]

Example 5 A polycrystalline diamond film was formed on a molybdenum substrate having various surface roughness for various times by the hot filament CVD method using a tantalum filament having a diameter of 0.5 mm and a length of 60 mm under the following conditions. did. Raw material gas: H ₂ 100 ccm Ethanol 5 ccm Pressure: 200 torr Filament temperature: 2200 ° C. Substrate temperature: 900 ° C. Filament-substrate distance: 6 mm

After the film formation was completed, the molybdenum substrate was removed with a 1: 1 aqueous solution of nitric hydrofluoric acid to obtain only a polycrystalline diamond film. These diamond films are cut into a tool edge shape by a YAG laser, and various ceramic chips (SPGN12030) are formed by using silicon or silicon alloy.
Various polycrystalline diamond chips were manufactured by bonding to the cutting edge of 8) and performing cutting. These chips were further coated with diamond films of various thicknesses by the hot filament CVD method. Table 6 shows the thickness of the diamond film (a is the thickness of the diamond directly bonded with silicon or a silicon alloy, b is the thickness of the diamond coating the surface of the bonded diamond), bonding conditions, and the type of chip substrate. .

[0056]

[Table 6]

The cutting performance of these chips was evaluated. The shape of the work material is four Al-16% Si alloy plates protruding at the same length in the longitudinal direction at 90 ° intervals from the side surface of the cylinder, cutting speed: 500 m / min, cut depth: 2 mm, Feed: 6 mm in the longitudinal direction on the outer circumference of the Al-16% Si alloy protruding under the cutting condition of 0.2 mm / rev.
It was cut intermittently for 0 minutes. The cutting test results are shown in Table 7 below. It can be seen that the diamond tip of the present invention is excellent in fracture resistance even after cutting for 60 minutes, with no fracture of the cutting edge. On the other hand, chips whose surface was not coated with diamond (No. 6) and coated diamonds with a thin film thickness (No. 6)
Both of 7) and the diamond sintered body chip (No. 10) were observed to have chipped edges after cutting for 5 minutes. Further, in sample No. 8 in Table 6, an attempt was made to coat the surface with diamond after brazing, but the brazing material was eluted and a film could not be formed. Further, in sample No. 9, diamond and silicon were oxidized and could not be joined.

[0058]

[Table 7]

[0059]

EFFECT OF THE INVENTION The present invention is configured as described above, and is excellent in heat resistance by using silicon or a silicon alloy as a brazing material for brazing the diamond film member to the cutting action portion of the base material. A high-strength vapor-phase synthetic diamond brazing tool was obtained. Further, in the vapor phase synthetic diamond brazing tool as described above, at least the exposed diamond film member is further covered with the vapor phase synthetic diamond film, whereby the toughness is remarkably enhanced and excellent fracture resistance is exhibited. A vapor phase synthetic diamond brazing tool was realized.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a process in which a diamond nucleus grows into a columnar structure on a substrate.

FIG. 2 is an explanatory view showing a cutting edge portion of a tool in which a diamond film member is brazed to a tool base material.

FIG. 3 is an explanatory view showing a cutting edge portion of a vapor phase synthetic diamond brazing tool coated with a diamond film.

FIG. 4 is an explanatory view showing a state in which a diamond film 10 is formed on a Si substrate 12.

FIG. 5: Diamond film 10 and Si substrate 1 after cutting
It is explanatory drawing which shows 2.

FIG. 6 is a perspective view showing the appearance of the diamond film member 5.

FIG. 7 is an explanatory view showing how the silicon powder 14 is inserted between the diamond film member 5 and the cemented carbide tip 15.

FIG. 8 is an explanatory view showing a state in which the diamond film 10 which does not dissolve and remove the Si substrate 12 is brazed to the cemented carbide tip 15.

FIG. 9 is a perspective view showing the external appearance of the produced vapor-phase synthetic diamond brazing tool.

[Explanation of symbols]

 1 Substrate 2 Diamond Nucleus 3 Diamond Grain 4 Columnar Structure 5 Diamond Film Member 6 Tool Base Material 7 Brazing Material Layer 8, 10 Diamond Film 12 Si Substrate

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical display location C30B 29/04 W 8216-4G (72) Inventor Tatsuya Yasunaga 1-5 Takatsukadai, Nishi-ku, Kobe-shi, Hyogo No. 5 In Kobe Research Institute of Kobe Steel, Ltd. (72) Inventor Kazuhisa Kawada 1-5-5 Takatsukadai, Nishi-ku, Kobe City, Hyogo Prefecture Inside Kobe Research Institute of Kobe Steel, Ltd. (72) Masanori Cai 1-5-5 Takatsukadai, Nishi-ku, Kobe City, Hyogo Prefecture Kobe Steel Works, Ltd. Kobe Research Institute

Claims (10)

[Claims] 1. A diamond film member, which has been formed in advance in a shape corresponding to the outer shape of a tool base material made of cemented carbide or ceramics by a vapor phase synthesis method on the working portion, is made of silicon or a silicon alloy. A vapor-phase synthetic diamond brazing tool, which is brazed via a brazing material. 2. The brazing filler metal has a thickness of 0.5 to 100 μm.
The vapor-phase synthetic diamond brazing tool according to claim 1, wherein m is m. 3. A silicon alloy is used in the periodic table 4A, 5
The vapor phase synthetic diamond brazing tool according to claim 1 or 2, which contains one or more kinds of metal elements selected from the group consisting of metal elements of Group A and 6A. 4. A diamond film member is vapor-phase-synthesized on a brazing filler metal made of silicon or a silicon alloy, and then the brazing filler metal side is brought into contact with the tool base metal on an operating portion of the tool base metal made of cemented carbide or ceramics. The method for producing a vapor-phase synthetic diamond brazing tool, comprising: arranging the brazing filler metal in the above position and subsequently melting and brazing the brazing filler metal to braze the diamond film member onto the tool base metal. 5. After synthesizing a diamond film member on a substrate by a vapor phase synthesis method, the joint surface side of the diamond film member and the substrate is the rake face side of a tool base material made of cemented carbide or ceramics. And a brazing material made of silicon or a silicon alloy is arranged between the tool base material and the diamond film member, and the brazing material is melted and then cooled and solidified so that the diamond film member is placed on the tool base material. A method for manufacturing a vapor phase synthetic diamond brazing tool, which comprises brazing the substrate and removing the substrate before or after the brazing. 6. A diamond film member formed in advance in a shape corresponding to the outer shape of a tool base material made of cemented carbide or ceramics by a gas phase synthesis method on a working portion is made of silicon or a silicon alloy. A vapor phase synthetic diamond brazing tool, wherein the vapor phase synthetic diamond brazing tool is brazed via a brazing material, and at least the exposed portion of the diamond film member is further coated with a vapor phase synthetic diamond film. 7. The vapor phase synthetic diamond brazing tool according to claim 6, wherein the surface of the vapor phase synthetic diamond film to be coated is oriented in the (100) plane of the diamond crystal plane. 8. The vapor phase according to claim 6 or 7, wherein the vapor phase synthetic diamond film to be coated has an average film thickness of 1 to 200 μm, and the total diamond film thickness on the rake face side is 50 to 1000 μm. A synthetic diamond brazing tool. 9. A silicon alloy is selected from the group consisting of 4A and 5 of the periodic table.
The vapor-phase synthetic diamond brazing tool according to any one of claims 6 to 8, which contains one or more kinds of metal elements selected from the group consisting of A and 6A group metal elements (excluding Cr). . 10. After synthesizing a diamond film member on a substrate by a vapor phase synthesis method, a joint surface side of the diamond film member and the substrate is a rake face side of a tool base material made of cemented carbide or ceramics. And a brazing material made of silicon or a silicon alloy is arranged between the tool base material and the diamond film member, and the brazing material is melted and then cooled and solidified so that the diamond film member is placed on the tool base material. After brazing, removing the substrate before or after brazing, and further performing a cutting process on the diamond film member, at least the exposed portion of the diamond film member is coated with a vapor phase synthetic diamond film. A method for manufacturing a vapor phase synthetic diamond brazing tool, comprising: