JPH10287491A - Diamond-coated hard member having regulated surface roughness - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a diamond-coated hard member, excellent in abrasion, peeling and chipping resistances and having a regulated surface roughness practicable especially as a cutting tool. SOLUTION: This diamond-coated hard member is obtained by coating the top surface of a substrate with a coating film of diamond and/or diamondlike carbon. The average surface roughness of the substrate adjacent to the coating film is regulated to 0.1-2.5 μm expressed in terms of Ra and the average surface roughness of the coating film is regulated to <=1.5 μm expressed in terms of the Ra . The diamond-coated hard member has the relationship of Ra (c)<=Ra (s) when the average surface roughness of the coating film is expressed as Ra (c) and that of the substrate is expressed as Ra (s). The Ra is in conformity to the contents of the description in the Japanese Industrial Standards JIS B0601.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diamond coating having a controlled surface roughness, characterized in that the coating is dense, the quality of the coating is excellent, and the adhesion and peeling resistance of the coating are excellent. For a hard member, specifically, a turning tool, a drill, an end mill, a reamer, and a milling tool are prepared by adjusting the surface roughness of a base material and the surface roughness of a diamond-based film coated on the base material. Tools such as cutting tools, cutting tools such as slitters, nozzles, optical element molding dies, wear-resistant tools such as bond tools, which emphasize wear and friction resistance, as well as electronics and precision The present invention relates to a diamond-coated hard member whose surface roughness is adjusted, which can be practically used as a structural member and a functional member used in the industrial and chemical industries.

[0002]

2. Description of the Related Art Conventionally, studies have been made on diamond-coated sintered alloys in which a diamond and / or diamond-like carbon film is coated on a substrate of a sintered alloy represented by a cemented carbide. Attempts have been made to put the film into practical use as a tool material, especially a cutting tool, by exerting the wear resistance of the film.

[0003] In a diamond-coated sintered alloy, diamond and / or diamond-like carbon is poor in wettability with other substances. The biggest problem is how to coat the coating with enhanced adhesion. Even if a coating of diamond and / or diamond-like carbon is coated on a variety of substrates with a certain degree of adhesion and adhesion, when applied to a tool material, the coating may be applied in practical use. There is a problem that peeling or chipping is easily caused.

[0004] In particular, turning tools, milling tools, drills,
In the case of cutting tools typified by end mills, tools such as molds, cutting blades, and wear-resistant tools typified by cutting blades, they are used under the most severe conditions. And the surface roughness of the coating have become more important issues.

[0005] Many diamond-coated sintered alloys which can be used as a tool by enhancing the adhesion between a diamond and / or diamond-like carbon coating and a substrate have been proposed. Representative examples of etching of the surface of the semiconductor device are disclosed in JP-A-63-53269 and JP-A-1-201.
475, JP-A-1-246361, JP-A-2-217398, JP-A-3-107460, and JP-A-3-115571. Representative representatives have been proposed for the surface roughness of a substrate. Japanese Patent Application Laid-Open No. 7-223101 discloses a typical method.

[0006]

Among the prior arts proposed for the surface portion of a diamond-coated sintered alloy substrate, JP-A-63-53269 and JP-A-1-201.
No. 475, JP-A-1-246361, JP-A-2-217398, JP-A-3-107460 and JP-A-3-115571 disclose that the surface of a substrate made of a cemented carbide is treated with an acid. Etching,
In particular, JP-A-2-217398 and JP-A-3-13-1
JP 07460 discloses that the surface of the substrate is electrolytically polished and etched with an acid or a neutral substance to coat the surface of the substrate with a diamond film from which the binder phase present on the surface has been removed. ing.

[0007] Since the diamond-coated sintered alloy obtained by the methods disclosed in these publications is etched by an acid solution, only the binder phase is etched, and the surface roughness of the substrate surface before and after etching is reduced. Since the fluctuation is not so large and it is difficult to make an ideal uneven surface, there is a problem that the adhesion and adhesion of the diamond film coated on the substrate surface cannot be satisfied. In that case, there is a problem that the service life becomes short.

Further, as disclosed in JP-A-2-217398 and JP-A-3-107460, when the etching depth of the substrate surface is increased by electrolytic polishing and etching using an acid, However, in addition to the above-described problems, there is a problem that the strength of the substrate surface portion is further reduced.

Japanese Patent Application Laid-Open No. 7-223101 discloses that the surface roughness of the bonding surface between a substrate and a diamond coating is R
It is disclosed that a is adjusted to 0.1 to 3 μm.
However, the diamond-coated sintered alloy disclosed in this publication has extremely low adhesion and adhesion between the substrate and the diamond coating because the surface roughness of the diamond coating is not adjusted, and when used as a tool, There is a problem that the service life is likely to be short due to peeling of the coating and chipping.

[0010] Further, other technical documents disclose that it is possible to achieve a longer life if the surface roughness of the diamond film coated on the surface of the substrate is reduced by polishing the surface. There is. In this case, compared to the conventional diamond coated member, by reducing the diamond film surface roughness, there is a tendency of long life, but because the surface roughness of the substrate is not adjusted, When used under more severe conditions, there is a problem that the service life tends to be short due to a decrease in the adhesion and adhesion between the base material and the coating, and peeling and chipping of the coating.

The present invention has solved the above-mentioned problems, and more specifically, by adjusting the surface roughness of a base material of a metal, an alloy, a sintered alloy, or a ceramic sintered body, Diamond nuclei can be formed easily and in large quantities at the time of forming a film to be coated on the base material surface, a dense film can be formed, and the film quality is excellent, and the film surface roughness after film formation By adjusting the thickness, the abrasion resistance and friction resistance of the coating are improved in practical use, and the adhesion and adhesion to the base material are further improved, so that the coating thickness can be increased. The purpose is to provide a diamond-coated hard member with adjusted surface roughness that can be practically used as a cutting tool, especially because it is excellent in wear resistance, peeling resistance and chipping resistance when combined. is there.

[0012]

Means for Solving the Problems The present inventors have been conducting research for many years to achieve the above object,
The surface roughness of the substrate made of cemented carbide greatly affects the nucleation amount and film quality of diamond during the vapor phase synthesis of diamond. The first finding was that there is an optimum surface roughness of the substrate surface in order to greatly affect the adhesion and to maximize both of these effects.

Further, the present inventors have found that when a diamond film is coated on the surface of a substrate by a vapor phase synthesis method, the surface roughness of the film surface has a great effect on friction and abrasion with a partner material in practical use. And from the relationship between the surface roughness of the substrate surface and the surface roughness of the coating surface, it is possible to maximize the peeling resistance of the coating film, and as a result, the service life becomes long when used as a cutting tool. Obtained knowledge. The present invention has been completed based on these first and second findings.

That is, the diamond-coated hard member of the present invention is a diamond-coated hard member in which a coating of diamond and / or diamond-like carbon is coated on a substrate, and the average surface of the substrate adjacent to the coating is provided. The roughness is adjusted to 0.1 μm to 2.5 μm in Ra display, the average surface roughness of the coating is adjusted to 1.5 μm or less in Ra display, and the average surface roughness of the coating is Ra (C), and when the average surface roughness of the substrate is represented by Ra (s), Ra (c) ≦ Ra (s)
It is characterized by consisting of. (However, Ra
Is based on the content described in Japanese Industrial Standard JIS B0601)

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The base material of the diamond-coated hard member of the present invention is obtained by a diamond vapor phase synthesis method.
There is no problem as long as it is a material which does not deform and which can withstand practical use after the film is coated on the substrate surface. Specifically, for example, Si, Ti, Zr, Hf, V, Ta,
Nb, W, Mo, Cr metals, alloys containing at least one of these metals, alloys such as high-speed steel, die steel, or sintered alloys such as cermet, cemented carbide, or silicon nitride-based sintered Ceramics, such as sintered bodies, silicon carbide-based sintered bodies, and tungsten-based carbide-containing sintered bodies, or the surfaces of these metals, alloys, sintered alloys, and ceramics sintered bodies have diamond and / or diamond-like A member coated with a single-layer or multi-layer thin film made of an inorganic substance other than carbon can be given.

Among these base materials, at least one hard material selected from the group consisting of elements of groups 4a, 5a and 6a of the periodic table, carbides, nitrides and oxides of Si and Al, and their mutual solid solutions. Of a ceramic sintered body composed of a phase and unavoidable impurities, or a hard phase containing 99% by weight or more of tungsten carbide as a main component, and a binder phase containing Co and / or Ni as a main component, and unavoidable impurities. And a binder phase composed mainly of Co and / or Ni of more than 1% by weight and not more than 10% by weight and a hard phase composed mainly of tungsten carbide as a balance, and unavoidable impurities In the case of a substrate made of a cemented carbide consisting of the following, it is preferable because it is easy to enhance the film quality of the diamond film by the vapor phase synthesis method.

In particular, in the case of a substrate made of the above-mentioned cemented carbide, when used as a cutting tool, the base material itself is excellent in strength and toughness, so that a long life can be exhibited. Which is preferable. As the cemented carbide, a cemented carbide conventionally used in practice, for example, a cemented carbide described in JIS B4104 and B4053 can be used. Specifically, C
a hard phase containing 1 to 15% by weight of a binder phase mainly containing o and / or Ni and a balance of only tungsten carbide, or 8
This is a cemented carbide comprising a hard phase comprising at least 20% by weight of at least one of tungsten carbide of at least 0% by weight and another carbide, nitride or carbonitride. Among these cemented carbides, in particular, a cemented carbide composed of 1 to 10% by weight of the above-mentioned binder phase and the balance of the above-mentioned hard phase is preferable from the viewpoint of diamond film formation and practical strength and toughness. is there.

[0018] In the cemented carbide substrate, specifically, the binder phase is Ni, Co, a mixture of Ni and Co, or Ni.
-Co alloy, or a mixture of Ni and / or Co with another metal or a mutual alloy. Of these, the binder phase containing a metal other than Ni and Co is specifically, for example, Co-Fe
Alloy, Ni-Fe alloy, Ni-Mo alloy, Co-Mo alloy, Ni-Co-Mo alloy, Co-Ni-Fe alloy, C
o-Cr alloy, Ni-Cr alloy, Co-Ni-Cr alloy, Co-Fe-Cr alloy, Ni-Fe-Cr alloy, C
o-V alloy, Ni-V alloy, Co-Ni-V alloy, Co
-Ni-Cr-V alloy, Co-Cr-V alloy, Ni-C
r-V alloy, Co-W alloy, Ni-Cr-Mo alloy can be mentioned. The binder phase preferably contains at least one of Co and Ni in an amount of 50 wt% or more based on the binder phase. When used in a rotating tool represented by a drill and an end mill, the content of the binder phase is particularly preferably from 2 to 10% by weight based on the entire cemented carbide, and the content of the binder phase has an effect of suppressing grain growth of the hard phase. It is more preferred that high Cr and / or V be contained.

Furthermore, these metals, alloys, sintered alloys,
In the case of a substrate in which the surface of the ceramic sintered body is coated with a thin film made of an inorganic substance other than the diamond and / or diamond-like carbon coating, the nucleation and growth of diamond are not inhibited during the synthesis of the diamond coating. Selection of a thin film made of a substance,
This is preferable because the strength and toughness of the entire substrate can be selected. Specifically, for example, TiN, TiCN, (TiAl)
One kind of monolayer or two of N, SiC, Si ₃ N ₄ , Si
Substrates coated with a thin film composed of at least two or more kinds can be given. The thickness of the thin film at this time may be a minimum thickness at which the effect can be exerted at the time of forming the above-mentioned film, and is specifically 0.1 μm or more, preferably 0.5 to 5 μm.

This substrate has an average surface roughness of Ra = 0.1 μm to 2.5 μm on the substrate surface adjacent to the diamond and / or diamond-like carbon coating. The average surface roughness of the substrate surface is Ra <
In the case of 0.1 μm, the adhesion and adhesion of the coating to the substrate are poor, and conversely, the average surface roughness of the substrate surface is Ra>
In the case of 2.5 μm, the surface roughness of the diamond and / or diamond-like carbon coating film coated on the base material becomes coarse. This may cause peeling and roughen the finished surface of the work material as the mating material, resulting in a short life. In addition, even if the coating surface roughness is adjusted by wrapping or the like after coating, the adjustment of the coating surface roughness having the highest hardness among the substances takes a long time,
The chance of damaging the coating is increased. Therefore, the average surface roughness of the substrate surface is Ra = 0.1 μm to 2.5 μm
It is defined.

The coating of diamond and / or diamond-like carbon coated on the substrate has an average surface roughness of Ra ≦ 1.5 μm. When the average surface roughness of the coating is Ra> 1.5 μm, as described above, for example, when used as a cutting tool, the cutting resistance increases, which may cause chipping and peeling of the coating. However, there is a problem that the finished surface of the work material is roughened and the life is shortened. The average surface roughness of this coating is R
It is preferable that a ≦ 1.0 μm, and it is particularly preferable that Ra = 0.1 to 1.0 μm. Although the optimum value of the film thickness varies depending on the application, the average film thickness should be 1 to 15 μm to obtain a film thickness that can be used even under severe conditions such as cutting tools or wear-resistant tools. Is preferable.

The ratio between the surface roughness of the substrate surface and the surface roughness of the coating surface is important. If the surface roughness of the coating surface is larger than the surface roughness of the substrate surface, the film has a high adhesion resistance and adhesion resistance. , The deterioration of peeling resistance and chipping resistance becomes remarkable,
In addition, it will increase friction and increase damage to the mating material.

The surface roughness of the substrate in the diamond-coated hard member of the present invention is adjusted by a conventional method for adjusting the surface roughness, such as polishing, lapping, corrosion, barrel processing, shot peening, and the like. It can be adjusted by a method such as heat treatment. This is specifically described for a cemented carbide substrate.For example, the surface of a cemented carbide that is a baked surface or a polished surface is made of a hard phase existing on the surface of the cemented carbide in an alkaline solution. The surface roughness of the substrate can be adjusted by performing electrolytic corrosion and then corroding the binder phase present on the surface of the cemented carbide in an acid solution.

Using the substrate whose surface roughness has been adjusted in this way, the diamond and / or diamond is added to the surface of the substrate by, for example, conventional microwave plasma chemical vapor deposition or high frequency plasma chemical vapor deposition. A coating made of diamond-like carbon is applied. At this time, it is also possible to adjust the surface roughness of the substrate by adjusting the surface roughness of the substrate and the conditions for forming the film to be coated on the surface of the substrate, and in this case, the post-process is omitted. This is preferable because the surface roughness of the coating film can be adjusted to an optimum value for improving the service life. However, since the surface roughness of the coating has a narrow adjustment range, after the coating is formed, for example, a conventional lapping method using a fine diamond paste, an oxidation method by frictional contact with a metal oxide, a hot corrosion method, etc. It is particularly preferable to adjust the surface roughness of the coating.

[0025]

The diamond-coated hard member of the present invention controls the surface roughness of the substrate to induce the generation of diamond nuclei during the formation of the coating, and to produce a high-quality coating. In addition, the coating is formed in a wedge-like manner into the unevenness of the surface of the base material, thereby increasing the adhesion and adhesion between the base material and the coating. Further, the diamond-coated hard member of the present invention, by adjusting the surface roughness of the coating, acts to reduce the frictional resistance with the mating material, the surface roughness of the coating is equal to the surface roughness of the substrate, Alternatively, by making the surface roughness of the coating smaller than the surface roughness of the base material, the adhesion and adhesion between the base material and the coating can be further improved, the peeling resistance of the coating, the fracture resistance of the member, It also has an indirect action of increasing chipping resistance and increasing the finished surface roughness of the work material which is the mating material when used as a cutting tool.

[0026]

Example 1 A commercially available average particle size of about 0.5 to 2 μm
m, and weighed into the composition components shown in Table 1, mixed and pulverized, powder compacted and sintered (sintering conditions, 1 ×
10 ^-2 Torr, 1400-1600 ° C, 50 minutes) and the shape and surface roughness are SNG of JIS standard
A substrate of a sintered body corresponding to N120408 was obtained. Using these base materials, the surfaces of the respective base materials were electrolytically corroded by flowing a direct current with each base material serving as an anode and a copper plate serving as a cathode in the alkaline solution shown in Table 1. Next, after cleaning and drying each substrate surface, each substrate surface was corroded by the acid treatment described in Table 1. Next, each substrate is placed in a microwave plasma CVD apparatus after the surface is scratched by diamond abrasive grains, washed, and dried, and is subjected to microwave output in an atmosphere of hydrogen: 200 SCCM, methane: 1 SCCM, pressure: 40 Torr. : 2.1 kw, substrate temperature: 950 ° C, the surface of each substrate was coated with a diamond film to obtain products 1 to 9 of the present invention.

As a comparison, the surface roughness of the base material and the coating was adjusted by polishing and lapping.
Comparative products 4 to 6 were treated in the same manner as the product of the present invention described above, except that electrolytic corrosion in an alkaline solution on the substrate surface was not performed. Moreover, except that the base materials having different surface roughnesses were used, comparative products 7 to 9 were obtained by performing the same treatment as the above-described present invention product.

With respect to the thus obtained inventive products 1 to 9 and comparative products 1 to 9, the surface roughness of the substrate after film formation and the surface roughness of the film were measured at five points at random, and the average surface roughness of each was measured. And the results are shown in Table 2. The coating thickness of each of the products 1 to 9 of the present invention and the comparative products 1 to 9 is about 10 μm.
Met. Further, the maximum load at which the films of the present invention products 1 to 9 and the comparative products 1 to 9 peeled off was determined using a film peeling resistance tester corresponding to the scratch hardness tester.
It was also described in. Next, products 1 to 9 of the present invention and comparative products 1 to 9
Work material: Al-18 wt% Si alloy, cutting speed: 900 m / min, feed: 0.1 mm, cutting depth:
A turning test was conducted under the conditions of 0.5 mm and dry cutting, and the life when the flank wear amount was 0.3 mm or when chipping or chipping occurred was defined as the life, and the cutting time until the life was calculated.
It was also described in.

[0029]

[Table 1]

[0030]

[Table 2]

[0031]

Example 2 Various powders used in Example 1 were weighed into the composition components shown in Table 3 and had a shape of 6 mm in diameter.
A drill having a length of 80 mm was used as a base material. Corrosion by a corrosive solution described in Table 3 and coating of the coating were performed from the tip of the drill to about 20 mm. Invention product 1 of Example 1 except that tungsten wire, hydrogen: 200 SCCM, methane: 1 SCCM, pressure: 30 Torr, filament temperature: 2000 ° C., and substrate temperature: 900 ° C.
Inventive products 10 to 18 were obtained in substantially the same manner as in Examples 9 to 9.

For comparison, the surface roughness of the base material and the coating was adjusted by polishing and lapping.
Comparative products 13 to 15 were obtained by treating in the same manner as the above-mentioned present invention product, except that electrolytic corrosion in an alkaline solution on the substrate surface was not performed. Also, except that a substrate having a different surface roughness was used, comparative products 16 to 18 were obtained by performing the same treatment as the above-mentioned inventive product.

With respect to the thus-obtained inventive products 10 to 18 and comparative products 10 to 18, the surface roughness of the base material and the surface roughness of the film after film formation were randomly measured at five points, and the average surface roughness of each was measured. And the results are shown in Table 4. In the same manner as in Example 1, the peeling resistance of the coating was determined and also shown in Table 4. The products 10 to 18 of the present invention and the comparative products 10 to 18
Was about 10 μm. Next, the product 1 of the present invention
Work material: A using No. 0-18 and Comparative products 10-18
1-30wt% Si alloy, cutting speed: 230m / mi
n, feed per rotation: 0.2 mm / rev, hole depth: 2
A hole drilling test was performed under the condition of 0 mm, wet cutting with a water-soluble emulsion, and when the shape of the machined hole was defective, or when the drill was chipped or chipped, the life was determined. did.

[0034]

[Table 3]

[0035]

[Table 4]

[0036]

Example 3 Using a micron drill base material having the composition of the base material shown in Table 5 and having a diameter of 0.5 mm and a length of 50 mm, Table 5 also shows about 5 mm from the tip of the edge of the drill. Electrolytic corrosion in an alkaline solution and corrosion by an acid solution were performed, and a tungsten wire was made into a filament by a hot filament device. Hydrogen: 200 SCCM,
Except that the coating was applied under the conditions of methane: 2 SCCM, pressure: 40 Torr, filament temperature: 1840 ° C., and substrate temperature: 950 ° C., the treatment was performed in substantially the same manner as the products 1 to 9 of the present invention in Example 1. Products 19 to 24 of the present invention were obtained.

As a comparison, the surface roughness of the substrate and the coating is adjusted by polishing and lapping, and the surface of the substrate is treated in the same manner without electrolytic corrosion of an alkaline solution and corrosion of an acid solution. Comparative products 19 to 20 were obtained in which the ratio between the surface roughness of the substrate and the surface roughness of the coating deviated from the product of the present invention. Further, the base material having the composition described in Table 5 was used, and only the corrosion of the acid solution was performed without performing the electrolytic corrosion in the alkaline solution on the surface of the base material. Thus, comparative products 21 and 22 were obtained. Further, the base material having the composition described in Table 5 was used, and the surface roughness of the base material was set so as to deviate from that of the product of the present invention. The solution was corroded, and the others were treated in substantially the same manner.
24 was obtained.

With respect to the thus obtained inventive products 19 to 24 and comparative products 19 to 24, the surface roughness of the base material after film formation and the surface roughness of the coating film were measured in the same manner as in Example 1, and the results were obtained. The results are shown in Table 6 and the peel resistance of the coating film was determined in the same manner as in Example 1 and also shown in Table 6. In addition, when the composition components in the surface portions of the base materials of the products 19 to 24 of the present invention and the comparative products 21 to 24 were confirmed, about 2 μm from the surface of the substrate toward the inside.
At a depth of m, the binder phase was reduced or removed. Further, the thickness of the coating was about 5 μm. Next, using the products 19 to 24 of the present invention and the comparative products 19 to 24, a work material: a plastic electronic circuit printed circuit board having a thickness of 0.6 mm laminated with Al and Cu, and a cutting speed of 1.
Under the conditions of 4 m / min, feed per rotation: 2 μm / rev, hole depth: 3 mm, atmosphere: dry cutting, a drilling test was performed on the printed circuit board. Table 6 also shows the number of holes processed up to this point.

[0039]

[Table 5]

[0040]

[Table 6]

[0041]

Example 4 Various powders used in Example 1 were weighed into the composition components shown in Table 7, and the powder having a diameter of 6 mm was obtained.
The base material of a 4-flute end mill having a length of 70 mm and a blade length of 30 mm was used. Corrosion and coating of the coating solution were performed from the tip of the blade up to about 30 mm with the corrosive solution described in Table 7; Filament device, filament: tungsten wire, hydrogen: 250 SCCM, methane:
2.3 Inventive product 25 in substantially the same manner as inventive products 1 to 9 of Example 1 except that the pressure was 30 Torr, the filament temperature was 1860 ° C., and the substrate temperature was 950 ° C.
~ 30 was obtained.

As a comparison, the surface roughness of the substrate and the coating was adjusted by polishing and lapping, and the surface of the substrate was treated in substantially the same manner without electrolytic corrosion of an alkaline solution and corrosion of an acid solution. Comparative products 25 to 26 were obtained in which the ratio between the surface roughness of the base material and the surface roughness of the coating deviated from the product of the present invention. Moreover, except that the electrolytic corrosion in the alkaline solution on the base material surface was not performed, it processed similarly to the above-mentioned present invention product, and obtained comparative products 27-28. In addition, except that the surface roughness of the base material was different, the same treatment as that of the above-described present invention product was performed to obtain comparative products 29 to 30.

With respect to the thus obtained inventive products 25 to 30 and comparative products 25 to 30, the surface roughness of the base material and the surface roughness of the film after film formation were randomly measured at five points, and the average surface roughness of each film was measured. And the results are shown in Table 8. In the same manner as in Example 1, the peeling resistance of the coating was determined and also shown in Table 8. In addition, the product of the present invention 25-30 and the comparative product 25-30
Had a coating thickness of about 15 μm. Next, the product 2 of the present invention
Work material: C using 5 to 30 and comparative products 25 to 30
/ C composite, tool overhang: 30 mm, cutting speed:
90m / min, depth of cut: 6mm in axial direction-2m in radial direction
m, feed per tooth: 0.02 mm / rev, dry cutting, end mill cutting test. When the flank wear width reaches 0.2 mm, the service life is calculated. 8

[0044]

[Table 7]

[0045]

[Table 8]

[0046]

Example 5 Various powders used in Example 1 were weighed into the composition components shown in Table 9 and the shape was 6 mm in diameter.
The base material of a four-flute end mill having a length of 70 mm and a blade length of 30 mm was used. Corrosion with a corrosion solution and a coating of the coating from Table 1 to about 30 mm from the tip of the cutting edge were performed. Filament device, filament: tungsten wire, hydrogen: 250 SCCM, methane:
Inventive product 31 in substantially the same manner as inventive products 1 to 9 of Example 1 except that 2.3 SCCM, pressure: 30 Torr, filament temperature: 1860 ° C, and substrate temperature: 950 ° C
~ 38 was obtained.

As a comparison, the surface roughness of the substrate and the coating was adjusted by polishing and lapping, and the surface of the substrate was treated in substantially the same manner without electrolytic corrosion of an alkaline solution and corrosion of an acid solution. Comparative products 31 to 34 having ratios of the surface roughness of the base material to the surface roughness of the coating film deviated from those of the present invention. Also, except that the surface roughness of the base material was different, the same treatment as that of the above-described present invention was performed to obtain comparative products 35 to 38.

With respect to the products 31 to 38 of the present invention and the comparative products 31 to 38 thus obtained, the surface roughness of the substrate after film formation and the surface roughness of the film were measured at five points at random, and the average surface roughness of each of them was measured. And the results are shown in Table 10. In the same manner as in Example 1, the peeling resistance of the coating was determined and also shown in Table 10. Was. In addition, products 31 to 38 of the present invention and comparative product 31
The film thickness of ３８38 was about 10 μm. Next, using the products 31 to 38 of the present invention and the comparative products 31 to 38, a work material: C / C composite, a tool protrusion: 30 mm, a cutting speed: 90 m / min, a cutting depth: 6 mm in an axial direction-2 mm in a radial direction, End mill cutting test was performed under the conditions of feed per tooth: 0.02 mm / rev and dry cutting, and the life when the flank wear width became 0.2 mm was defined as the life, and the processing length up to the life was calculated and shown in Table 10. Also described.

[0049]

[Table 9]

[0050]

[Table 10]

[0051]

Embodiment 6 A commercially available Mo plate, Si plate and silicon nitride-based sintered body were used as base materials, and the surfaces of these base materials were polished and polished.
After adjusting by lapping and corrosion treatment to produce substrates having various surface roughnesses, the products 1 to 9 of the present invention of Example 1 were prepared.
The surface of the base material is coated with a diamond film by applying the same procedure as described above, and the surface of each film is subjected to lapping with a diamond paste and oxidation diffusion treatment by heating friction with iron oxide powder to reduce the surface roughness of the film surface. It was adjusted. As a result of confirming the peeling resistance of the coating in the same manner as in the peeling resistance test of Example 1, the diamond-coated member having the substrate surface roughness and the coating surface roughness adjusted as a result showed that the substrate surface roughness, the coating surface roughness and the The ratio of the two is the present invention product 1 of Example 1.
Almost the same tendency as the relationship between No. 9 and Comparative products 1 to 9 was observed.

[0052]

The diamond-coated hard member of the present invention has the following features.
A comparative product whose surface roughness ratio between the substrate and the coating deviates from the range of the present invention, a comparative product which deviates from the range of the present invention in which the surface of the substrate whose surface is subjected to acid corrosion treatment is coated with a diamond film, and a surface Can be formed easily and in large quantities at the time of film formation as compared with a comparative product which is out of the range of the present invention, in which the surface of a substrate which has been subjected to corrosion treatment with an alkali solution and an acid solution is coated with a diamond film. After film formation, excellent adhesion and adhesion between the film and substrate, excellent film quality (low impurity content), and adhesion and adhesion to substrate It is possible to coat a thick coating film because of its superiority, and since the surface roughness of the coating is smaller than the surface roughness of the base material, friction with the mating material during practical use is reduced. Small and resistant耗性, peel resistance, to improve the chipping resistance, the effect of suppressing the damage of the counter material. From these, the diamond-coated hard member of the present invention can be used as a tool material,
It can be used as a cutting tool among tool materials, and the most severe rotating tool among cutting tools, specifically, for example, when used as an end mill, drill, micron drill for printed circuit board, cutting tip for milling, reamer An excellent effect of long life is exhibited. Furthermore, since it can be applied to various base materials, the effect that the diamond-coated hard member of the present invention can be used as a part used in electronic equipment, precision equipment, chemical equipment, medical equipment, and the like is expected.

Claims (7)

[Claims] 1. A diamond-coated hard member having a substrate coated with a coating of diamond and / or diamond-like carbon, wherein the average surface roughness of the substrate adjacent to the coating is 0.1 μm to 2 in Ra. 0.5 μm, the average surface roughness of the coating is adjusted to 1.5 μm or less in Ra display, and the average surface roughness of the coating is indicated as Ra (c). When the average surface roughness is expressed as Ra (s), Ra (c) ≦ Ra
(S) A diamond-coated hard member having a controlled surface roughness. (However, Ra conforms to the contents described in Japanese Industrial Standard JIS B0601) 2. The diamond-coated hard member with adjusted surface roughness according to claim 1, wherein said coating is coated by a plasma chemical vapor deposition method or a chemical vapor deposition method. 3. The average surface roughness of the coating is Ra = 0.
The diamond-coated hard member having a controlled surface roughness according to claim 1 or 2, wherein the thickness is 1 to 1.0 µm. 4. The coating has an average thickness of 1 to 15 μm.
4. The diamond-coated hard member with adjusted surface roughness according to claim 1, 2 or 3. 5. The base material is made of a sintered alloy made of a cemented carbide, a ceramic sintered body mainly containing at least one of tungsten carbide, silicon carbide, and silicon nitride, or a cemented carbide. 5. The diamond-coated hard member having the adjusted surface roughness according to claim 1, 2, 3, or 4. 6. The diamond coating of claim 5, wherein the surface of the substrate is adjusted by electrolytic treatment in an alkaline solution and acid corrosion treatment. Hard member. 7. The diamond-coated hard member is used as a cutting tool.
A diamond-coated hard member having a surface roughness adjusted to 3, 4, 5 or 6.