JPH0710443B2 - Cutting tip - Google Patents

Description

TECHNICAL FIELD The present invention relates to a cutting tip, and more particularly to a cutting tip excellent in mass productivity and cutting performance.

(Background of the Invention) Cemented carbides, oxides such as Al ₂ O ₃ , carbides such as SiC, Si ₃ N ₄ and nitrides, or cemented carbides coated with carbides and nitrides have been conventionally used as cutting tips. It is mainly used because of its excellent strength and abrasion resistance.

In recent years, diamond has attracted attention as a mechanical material and as a material having wear resistance, and its application to cutting tips is being studied.

As an application for cutting tips, natural diamond or a diamond-based sintered body obtained by firing a mixed powder of diamond powder and metal powder under ultra high pressure and ultra high temperature is joined to the cutting edge of the cutting tip. Also, there has been proposed a high-purity diamond film coated on the surface of a predetermined base material such as cemented carbide by a vapor phase growth method such as a thermal CVD method, a plasma CVD method, an ion beam method.

(Problems to be Solved by the Invention) However, in the method of joining the diamond-based sintered body to the blade edge, it is necessary to process the sintered body into a blade edge shape, and the production of the sintered body itself is large and Since a complicated device is required and mass production is difficult, the manufacturing process is complicated and there is a cost problem. Moreover, since the diamond-based sintered body generally contains an auxiliary component such as metal, there is a problem that the excellent characteristics of diamond cannot be sufficiently exhibited.

On the other hand, according to the method of coating a predetermined substrate with a diamond film by the vapor phase epitaxy method, an ultrahigh-pressure high-temperature device was used in that the film forming system is simple and a high-purity diamond film can be formed. It can be manufactured at a lower cost than the above method.

However, the method of using a diamond film by vapor phase growth requires a substrate at all times, and the cutting chip substrate itself must be installed in a narrow film forming space. There is a problem that the number of chips that can be obtained is small and it is not suitable for mass production. Further, the conventional cutting tip coated with a diamond film has a large problem that the diamond film is not sufficiently adhered to the tip substrate and the diamond film is easily peeled off during cutting. At present, the problem of poor adhesion is a major cause of impeding the application of diamond films to cutting chips.

(Object of the Invention) Therefore, an object of the present invention is to provide a cutting tip coated with a diamond film, which is capable of structurally increasing manufacturing efficiency, and which is inexpensive.

Another object of the present invention is to provide a cutting tip having a long life and excellent cutting performance without peeling of a diamond film.

(Means for Solving Problems) The present inventor has examined the cause of the decrease in the adhesion of the diamond film, and as a result, the vapor phase growth method is easily affected by the surface properties of the substrate and the like and is uniform over the entire film. It is difficult to obtain a film, and it is difficult to obtain a uniform film as the deposition area by the vapor phase growth method is large, and it is easy to peel from a non-uniform portion due to external stress during cutting. Obtained. Based on this knowledge, as a result of examination including mass productivity of the cutting tip coated with a diamond film, the cutting tip has a tip edge member and a divided structure of a tip base material for joining and supporting the tip edge member, By coating the diamond film with a thickness of 0.1 to 100 μm by a vapor phase growth method directly on at least the blade portion of the tip blade member or through an intermediate layer, the film forming area of the diamond film can be reduced, and thus the film uniformity can be improved. It has been found that a cutting tip which is free from peeling and has excellent cutting performance and mass productivity can be obtained.

Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is an exploded perspective view showing a cutting tip of the present invention. The cutting tip 1 includes a tip blade member 2 and a tip base material 3
The tip blade member 2 has a cutting blade portion 4 in a part thereof. Further, the tip member 2 is a substrate 5 for a blade, and a diamond film 6 is formed on the surface of the substrate 5 by vapor phase growth.
Is formed. Further, the chip base material 3 is provided with a pedestal 7 for supporting the chip edge member 2, and by supporting the chip edge member 2 on the pedestal 7 by means such as joining, the cutting chip 1 Is formed.

According to the present invention, with the above-described divided structure, it is not necessary to form the diamond film on the entire tip, and only the tip blade member 2 including the blade portion 4 can be formed. Since the film formation area can be reduced, the film formation of the diamond film can be made uniform, so that the problem of peeling of the diamond film during cutting can be solved. As a result, as is clear from the examples described below, the adhesion of the diamond film can be increased and the cutting life as a cutting tip is improved as compared with the case where the diamond film is formed on the entire surface of the cutting tip. can do. Further, since the diamond film can be coated only on the tip blade member,
Even if the cutting tip itself is large, the cutting tip coated with the diamond film can be easily manufactured without modifying the film forming apparatus or the like.

The substrate 5 for coating the diamond film of the tip blade member 2 of the present invention is a material having excellent mechanical strength such as strength and toughness as a cutting tip, for example, Si, MO, quartz, stainless steel, Al ₂ O. ₃ , cemented carbide, cermet, SiC, Si ₃ N
₄ , a known material such as zirconia is selected. In particular, considering the adhesiveness to the diamond film, it is preferable that the main component is SiC or Si ₃ N ₄ .

Further, according to the present invention, an intermediate layer having the component of the base 5 and the carbon component can be provided for the purpose of improving the adhesion of the diamond film 6. This intermediate layer can relieve the internal stress due to the difference in the coefficient of thermal expansion, which is one of the causes of peeling.

As the chip base material 3, known tool materials can be used, but especially Al ₂ O ₃ , Al ₂ O ₃ -TiC, Al ₂ O ₃ -ZrO ₂ , Si ₃ N ₄ , cemented carbide, cermet, partially stable Zirconia oxide (PSZ) and the like are preferable, and among these, Si ₃ N ₄ , cemented carbide, cermet, PSZ, and the like, which have relatively high toughness, are preferable.

The overall shape of the cutting tip of the present invention and the shape of the tip blade member are not limited to the shapes shown in FIG. 1, and any shape is applicable. For example, a convex portion may be formed on the tip blade member 2 and a concave portion may be formed on the chip base material so that the two are fitted together.

Further, even when the cutting tip 1 has a plurality of blade portions 4, the diamond coating treatment can be performed in the same manner for each blade portion.

When determining the shape of the tip blade member 2, it is important that the tip itself does not include a portion supported by a supporting member such as a holder. This is to prevent the diamond film from peeling off due to the stress when it is supported by the holder or the like.

Therefore, in the embodiment shown in FIG. 1, the shape of the tip blade member 2 is determined in the region excluding the support opening 8.

When manufacturing the cutting tip of the present invention, first, after manufacturing a cutting edge substrate, a sintered body of the shape of the chip base material, then for the cutting edge substrate, thermal CVD method, plasma CVD method, ions A diamond film is formed by a vapor phase growth method such as a beam method. According to this vapor phase growth method, since diamond is likely to be generated particularly in the corners of the substrate to be coated,
It is particularly effective for coating tools and the like. Among these vapor phase growth methods, for example, in the case of the plasma CVD method, the substrate 4 made of the above-mentioned desired material is placed in the reaction chamber, and a predetermined proportion of hydrocarbon (CH ₄ ) Introduce a mixed gas of hydrogen (H ₂ ), apply high frequency or microwave,
When a plasma is induced and this state is maintained for several hours, a diamond film is formed on the substrate. At this time, the smaller the blade tip substrate 5 is, the smaller the coating area is, the more the number of coating treatments can be processed, the more mass production can be performed, and the variation in the cutting performance of the finally obtained chips can be reduced. The stability as a product can be improved. In addition, when the substrate 5 is, for example, a triangular prism as shown in FIG. 1 when it is installed in the reaction tank, when it is later bonded to the chip base material 3 as shown in FIG. If one of the bonding surfaces (5a in FIG. 1) is placed back to back, it is possible to suppress the generation of the diamond film on the unnecessary surface and promote the generation of diamond on the blade portion 4 of the substrate 5. it can.

Moreover, by reducing the formation area of the diamond film, each diamond film is uniformly formed, and peeling can be reduced.

The film thickness of the diamond film provided on the cutting edge substrate is preferably 0.1 to 100 μm from the viewpoint of performance as a cutting tip.

In the present invention, as described above, an intermediate layer having a base component and a carbon component can be provided for the purpose of improving the adhesion of the diamond film. When forming the intermediate layer, for example, as a base before forming the diamond film,
When Si ₃ N ₄ is used, an intermediate layer consisting of diamond and Si ₃ N ₄ is provided by introducing a mixed gas in which SiH ₄ , NH ₃ and CH ₄ are mixed in a predetermined ratio and inducing plasma. You can After that, by performing the same operation as above in the same reaction system, the intermediate layer and the diamond film can be continuously provided on the surface of the substrate. Here, the intermediate layer may have a multi-layer structure by adding the third component, the fourth component, ... For the purpose of improving the adhesion in addition to having the base component and the carbon component as described above. The thickness of the intermediate layer is preferably set in the range of 0.01 μm to 1 mm, and this thickness is related to the material of the substrate, the carbon content of the intermediate layer, the content of other components, and the layer structure. According to the experiments repeated so far, the adhesiveness was more remarkably obtained by setting it within the above range.

Furthermore, it is desirable to set the thickness of the diamond film to be equal to or less than the thickness of the intermediate layer. That is, as a result of repeated experiments by the present inventors, although it is related to the base material, the layer structure of the intermediate layer and the composition material, when the thickness of the diamond film exceeds the thickness of the intermediate layer, internal stress It has been confirmed that there is a tendency that is likely to occur.

The tip blade member 2 having a diamond film formed on its surface is
Next, it is joined to the pedestal 7 of the chip base material 4. As a bonding method, a known technique such as a refractory metal method, a copper oxide method, or a copper sulfide method can be used, but it is necessary to carry out at a bonding temperature of 800 ° C. or lower in order to prevent graphitization of a diamond film at the time of bonding. is there.

The invention is illustrated by the following example.

Example 1 A Si ₃ N ₄ sintered body was used as the base of the tip member of the tip so as to have the shape of the cutting tip (TPGN322) shown in FIG. 1, and the refractory metal was previously formed on the surfaces 5a and 5b of FIG. Using the method
Metallization with Mo-Mn-Ti was performed.

Next, place the metallized substrate in the reaction chamber,
Microwave plasma CVD method, film thickness 7μm under the following conditions
A polycrystalline diamond film was formed.

The obtained cutting edge member was brazed with silver at a joining temperature of 600 ° C. to a pedestal 7 of a chip base material 4 made of cemented carbide (P10 equivalent) to obtain a cutting chip.

The cutting chips thus obtained were subjected to a cutting test as a performance test and an adhesion strength was measured by a scratching method using a diamond indenter on the coated surface. The adhesion strength was measured by gradually increasing the indenter load and measuring the load when peeling of the film occurred.

[Cutting test]

A. Measurement of flank wear Work material: Tough pitch copper Speed V; 500m / min Feed f; 0.1mm / rev Depth of cut d; 0.2mm Time t; 100min (maximum) B. Calculation of life equation Tough pitch copper Instead, use Al-Si (18%) alloy, feed f = 0.10mm / rev, cut d = 0.20mm
The velocity V is changed by and the equation of the VT curve is obtained. In addition,
The VT curve is represented by the general formula (1) VTx = C (constant) (1), and the life is determined by the x value and the C value. The smaller the x value and the larger the C value, the better the life. It is a thing.

The above measurement results are shown in Table 1. Also, the same characteristics as sintered diamond were obtained when cutting Ti-6Al-4V alloy.

Example 2 A cutting tip was obtained in the same manner as in Example 1 except that a SiC sintered body was used as the base of the blade member, and a performance test was conducted in the same manner as in Example 1 to find that good cutting performance was obtained. Indicated.

The results are shown in Table 1.

Example 3 SiC was used as the base of the blade member, and M was previously attached to the joint surface.
After metallizing o-Mn-Ti, the following process was performed.

A coil for high frequency current is installed outside the quartz tube as the reaction chamber.
A SiC substrate, which was formed into a winding and whose temperature was set to 900 ° C., was placed inside the wound substrate. A high-frequency current of 13.56 MHz is applied to the coil based on the high-frequency plasma CVD method, and H ₂ gas, CH ₄ gas, and SiH ₄ gas are each supplied at 200 cc / min inside the quartz tube,
Introduced at a flow rate of 2 cc / min and 0.5 cc / min to bring the total pressure gas to 10 To
It was set to rr and plasma was generated. When this was continued for 3 hours, a black intermediate layer could be formed with a thickness of 12 μm. When this intermediate layer was measured by micro X-ray diffraction, β-SiC was about 60% by volume and diamond was about 40% by volume.
It was confirmed that the composition was

Next, H ₂ gas and CH ₄ gas were added at 200 cc / min and 2 cc / min, respectively.
The total pressure gas was set to 20 Torr at a flow rate of min, and plasma was generated without changing other setting conditions. When this was continued for 3 hours, a blade member having a diamond film with a diamond film of 5 μm formed was obtained. It was confirmed that polycrystalline diamond was produced in this diamond film by any of X-ray diffraction, X-ray excited photoelectron analysis and Auger electron spectroscopy.

The cutting edge member was joined at a joining temperature of 650 ° C. to a tip base material of cemented carbide (P10 equivalent) by silver brazing to obtain a cutting tip. A performance test showed good cutting performance.

The performance test results are shown in Table 1.

Example 4 A Si ₃ N ₄ sintered body was used as the base body of the chip edge member, and the following operation was performed after metallizing the joint surface with Mo—Mn—Ti. H ₂ gas, SiH ₄ gas, NH ₄ gas and CH ₄ gas respectively
It was introduced into the reaction system at a flow rate of 100 cc / min, 10 cc / min, 10 cc / min and 5 cc / min, and plasma was generated for 30 minutes using a microwave of 2.45 GHz, and a thickness of 2 μm was formed on the Si ₃ N ₄ film. In SiC
And a first intermediate layer of Si ₃ N ₄ was formed. Next, H ₂ gas, CH ₄ gas and SiH ₄ gas were added at 100 cc / min and 2 cc / mi, respectively.
It was introduced at a flow rate of n and 1 cc / min and plasma was generated for 1 hour to form a second intermediate layer of diamond and SiC with a thickness of 2 μm on the first intermediate layer. After that, the flow rates of H ₂ gas and CH ₄ gas were changed to 100 cc / min and 0.5 cc / mi, respectively.
A polycrystalline diamond film having a thickness of 5 μm was formed by setting n. The substrate temperature during film formation was set to 900 ° C. for each film.

The obtained cutting edge member was joined at a joining temperature of 650 ° C. to a tip base material made of a cemented carbide (P10 equivalent) by silver brazing to obtain a tip for cutting. When the performance test was conducted, good results were obtained.

The performance test results are shown in Table 1.

Example 5 Using a TiC-based cermet substrate as the substrate for the tip member of the tip, H ₂ gas, TiCl ₄ gas and C ₂ H ₄ gas were each added to 1
2.45GH by introducing at the flow rate of 00cc / min, 2cc / min and 2cc / min
Plasma was generated by the microwave of z to form a layer of TiC and diamond with a thickness of 1 μm on the surface of the TiC-based cermet substrate. Then, every 15 minutes, the TiCl ₄ gas flow rate was sequentially reduced to 1.5 cc / min, 1 cc / min, and 0.5 cc / min, while the other gas flow rates were kept unchanged and the layers with the diamond content increased stepwise were 2 μm and 2 μm respectively The intermediate layer was formed with a thickness of 1 μm. After that, a TiCl ₄ gas flow rate was set to zero and a 6 μm polycrystalline diamond film was formed on the uppermost layer.

The obtained cutting edge member was joined in the same manner as in Example 1 to obtain a cutting tip. The performance test results are shown in Table 1.

Example 6 The following operation was performed using a cemented carbide as the base of the blade member.

80 cc / min and 20 c of H ₂ gas and Ar gas, respectively, to perform sputtering targeting WC with a high frequency power source.
It was introduced after setting to c / min. Next, when WC begins to deposit on the cemented carbide substrate by this sputtering, the flow rate of Ar gas is reduced at a rate of 10 cc / hour and CH ₄ gas is reduced to 1 cc / ho.
An intermediate layer consisting of WC and diamond film was formed by introducing while increasing at the speed of ur. Next, based on the high-frequency plasma CVD method, a high-frequency current of 13.56 MHz was applied to the coil from a high-frequency power source, and H ₂ gas and CH ₄ gas were each supplied at
When introduced at a flow rate of cc / min and 2 cc / min, a 6 μm polycrystalline diamond film could be formed on the intermediate layer.

The obtained cutting edge member was joined in the same manner as in Example 1 to obtain a cutting tip. When the performance test was conducted, good results were obtained. The results are shown in Table 1.

Example 7 The following operation was performed using Mo as the base material of the tip member of the tip. First, H ₂ gas, MoCl ₅ gas and CH ₄ gas were introduced at a flow rate of 250 cc / min, 10 cc / min and 1 cc / min, respectively 2.
Plasma is generated by 45 GHz microwave, then 1
MoCl ₅ gas is decreased by 1.5cc / min every 0 minutes and C
H ₄ gas is increased by about 0.15 cc / min and finally after 1 hour Mo
Cl ₅ gas and CH ₄ gas flow rate of 1cc / min and 2cc respectively
/ min to form an intermediate layer. After that, H ₂ gas and CH ₄
The flow rate of each gas was set to 100 cc / min and 2 cc / min to form a 6 μm polycrystalline diamond film.

The obtained cutting edge member was joined at a joining temperature of 650 ° C. to a tool base made of carbide by silver brazing to obtain a cutting tip.

A performance test showed good performance.

Example 8 The following operation was performed using stainless steel as the substrate of the tip member of the tip.

In Example 6, the target was Fe, and H ₂ gas and Ar gas were introduced at 80 cc / min and 20 cc / min, respectively, while performing the same operation method as in Example 6, and sputtering was performed. Then, when Fe starts to be deposited on the stainless steel substrate by this sputtering, the flow rate of Ar gas is changed to 10 cc / hour.
An intermediate layer consisting of Fe, FeCx and diamond was formed by introducing CH ₄ gas while increasing the rate of 1 cc / hour while reducing the rate at the same rate. After that, high frequency plasma CV
When a high frequency current of 13.56MHz is applied to the coil from a high frequency power source based on the D method and H ₂ gas and CH ₄ gas are introduced at a flow rate of 100cc / min and 2cc / min, respectively, from the gas inlet, 6μm on the intermediate layer The polycrystalline diamond film of was able to be formed.

The obtained cutting edge member was joined at a joining temperature of 650 ° C. to a tip base material made of cemented carbide by silver brazing to obtain a tip for cutting. A performance test was conducted and it was a good result.

The results are shown in Table 1.

Example 9 When manufacturing a cutting edge member by the method of Example 1, a plurality of substrates are arranged in a reaction chamber as shown in FIG. 2, and a 7 μm diamond film is simultaneously formed on a plurality of substrates under the same conditions as in Example 1. The cutting edge member was obtained.

A plurality of cutting tips made of the same material as in Example 1 was obtained from the obtained cutting edge member.

When a cutting test was performed on the plurality of cutting chips, it was confirmed that the results were all the same as shown in Table 1 and that the performance was uniform.

Comparative Example 1 A Si ₃ N ₄ sintered body having the same shape as that of Example 1 and a normal tool which is not divided into a blade member and a chip base material is coated with 5 μm of polycrystalline diamond under the same conditions as in Example 1. , A cutting tip was obtained.

When this cutting tip was subjected to the same performance test as in Example 1, it was found to be inferior to Example 1 particularly in terms of life.

The results are shown in Table 1.

Comparative Example 2 The same performance test was conducted using a cutting tip made of cemented carbide (WC94%, Co6%) and having the same shape as that of Example 1, and showed a performance inferior to that of the present invention. The result is first
Shown in the table.

Reference Example A cutting tip made of a Si ₃ N ₄ sintered body having the same shape as that of the tool of Example 1, and a diamond sintered body that is sintered under ultrahigh pressure and ultrahigh temperature is joined to the cutting blade. When the same cutting test was performed using the same, good results were obtained.

The results are shown in Table 1.

(Effect of the Invention) The present invention uses a cutting tip having a structure in which a blade member and a chip base material are divided as described above, and has a structure in which a diamond film is formed only on the blade member. As a result, it is possible to obtain a chip having excellent performance and mass productivity even when compared with a conventional diamond-coated tool.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of the cutting tip of the present invention, and FIG. 2 is a view showing the arrangement of the base during film formation. 1 is a cutting tip, 2 is a cutting edge member, 3 is a chip base material, 4
Indicates a blade portion, 5 indicates a blade tip substrate, and 6 indicates a diamond film.

Claims (2)

[Claims] 1. A chip edge member and a chip base material for joining and supporting the chip edge member, wherein the chip edge member has a thickness of 0.1 to at least directly on the blade portion or through an intermediate layer by a vapor phase growth method. A cutting tip having a 100 μm diamond film formed. 2. The cutting tip according to claim 1, wherein the tip blade member is made of a sintered body containing silicon carbide or silicon nitride as a main component.