JPH0617252A - Member coated with diamonds and its production - Google Patents

Abstract

PURPOSE:To provide the member coated with diamonds having a diamonds layer which is improved in adhesion to a base body by forming the diamonds layer on a specific solid soln. layer on the surface of the base material. CONSTITUTION:The surface of the base material is provided with the solid soln. layer. This solid soln. is formed of at least one kind selected from the group consisting of the carbide, nitride and carbonitride of >=2 kinds of the metals selected from the group consisting of the metals belonging to groups IVA, VA and VIA of the periodic table. The diamonds layer is formed on this solid soln. layer. The base material having the coating layer is subjected to a heating treatment at 1000 to 1600 deg.C in an inert gaseous atmosphere, by that, the solid soln. layer is formed on the surface of the base material. As a result, the surface accuracy on the working surface of the mating member to be worked is greatly improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diamond-coated member and a method for producing the same, and more specifically, excellent adhesion between a base material and a diamond film coating the base material,
The present invention relates to a diamond-coated member which exhibits excellent durability and has a significantly improved service life, and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, a wear resistant member such as a cutting tool, a grinding tool, and a polishing tool, and a wear resistant member such as a machine part, which are required to have high surface hardness and wear resistance, have a hardness and a wear resistance. The diamonds used are extremely excellent in. For example, generally known is a method of forming a diamond coating by depositing diamonds on the surface of a base material such as tools and wear resistant members by utilizing a diamond synthesis technique by a vapor phase method such as a CVD method or a PVD method. Has been. By coating the base material with the diamond coating in this way, it is possible to impart high surface hardness and wear resistance to tools and wear-resistant members.

However, the adhesion between the surface of the substrate and the diamond coating is generally poor. Therefore, various proposals have been made to improve this adhesion. As one of such proposals, an intermediate layer made of the base material component and the carbon component is formed on the surface of the base material made of various materials, or an intermediate layer made of a mixture of the base material component and diamond is formed. Attempts have been made to form a diamond film (diamond thin film) on the surface of the intermediate layer by a vapor phase synthesis method and to improve the adhesion between the base material and the diamond film by the intermediate layer ( JP-A-60-20
8473, JP 61-106478, JP 61-106493, and JP 61-1064.
94, etc.).

However, in the technique using the intermediate layer, the intermediate layer is required to maintain high adhesion to both the substrate and the diamond thin film, and moreover,
Since it is necessary to meet the strict requirement that the strength of the intermediate layer itself be sufficiently high, it is extremely difficult to select the optimum material. Actually, various ideas have been made in the selection of the material of the intermediate layer and the formation method thereof as in the conventional method illustrated above.
In any case, the diamond-coated member having the intermediate layer has not been sufficiently satisfied with both of the above and, particularly when used in severe conditions such as a cutting tool or a sliding member, has sufficient durability. There is a problem that the service life cannot be obtained.

Further, in JP-A-62-47480, the surface of a cermet base material is treated with an acid to form C.
A method of removing metal components such as o and Ni has been proposed. However, this method has a drawback that the surface of the base material becomes brittle, and due to the difference in thermal stress between the tungsten carbide and the diamond film, sufficient adhesion of the diamond film to the base material made of cermet can be obtained. However, there is a drawback that the diamond film is easily peeled off from the base material at a high temperature.

Further, the substrate is coated with a diamond film,
A method of heat-treating the obtained diamond-coated member is also known. However, in this method, although it is possible to obtain a diamond-coated member suitable for precision processing by removing fine cracks on the surface, almost no effect of improving the adhesion between the base material and the diamond film is obtained. I can't play.

On the other hand, as a method for improving the adhesiveness between the base material and the diamond thin film, various methods mainly focusing on the selection and modification of the material of the base material have been studied. For example, focusing on the fact that the poor adhesion between the base material and the diamond thin film is due to the difference in their thermal expansion coefficients, there is a method of controlling the thermal expansion coefficient by adjusting the composition of the base material and the sintering conditions. is there.

As such a method, for example, WC-Co
A method of adjusting the composition of the cemented carbide base material of the system, a method of adjusting the composition and the sintering conditions of the ceramic base material such as silicon nitride (Japanese Patent Laid-Open No. 61-109628) and the like have been proposed. However, in the case of a cemented carbide substrate, it is generally difficult to make its coefficient of thermal expansion sufficiently close to that of a diamond thin film by adjusting the composition and manufacturing conditions of the cemented carbide, and in fact The current situation is that the effect of improving sex is not fully achieved. On the other hand, in the case of ceramic base materials, since the emphasis is placed on controlling the thermal expansion coefficient of the base material itself, the material and composition of the base material is limited to an extremely narrow range, and even if the adhesion is improved. Even if it could be done, there was a problem that it was difficult to sufficiently satisfy the characteristics such as hardness and fracture toughness of the base material itself.

Further, in Japanese Patent Laid-Open No. 1-246361, carbides of IVa, Va, and VIa group metals in the periodic table,
At least one hard layer selected from the group consisting of nitrides, carbonates, oxynitrides and their mutual solid solutions, and Co and / or Ni.
A method has been proposed in which, after heat treatment or polishing treatment of a sintered bond gold composed of a bonding layer containing as a main component, a coating film composed of diamond-like carbon and / or diamond is formed on the surface thereof.

However, when the heat treatment under reduced pressure shown in the embodiment described in this publication is carried out, the bonding layer on the surface disappears to improve the adhesion of the diamond film to the sintered alloy. Although it can be seen, it has not reached a practical level.

In order to solve such a problem, Japanese Unexamined Patent Publication No.
Japanese Patent No. 115571 proposes a method of reducing the concentration of a bonding layer on the surface of a substrate by carburizing. However, since the tungsten carbide layer containing a large amount of carbon formed on the surface of the substrate is brittle, even if the adhesion of the diamond film to the tungsten carbide layer is improved, cohesive peeling occurs in the tungsten carbide layer. The problem remains that peeling is likely to occur.

An object of the present invention is to solve the above problems. That is, an object of the present invention is to provide a diamond-coated member having excellent adhesion between a substrate and a diamond film coating the substrate, exhibiting excellent durability, and significantly improving the service life. .

Another object of the present invention is to form a diamonds layer on the surface of a base material efficiently, and to improve the adhesion between the formed diamonds layer and the base material remarkably. It is to provide a method by which a component can be manufactured.

Still another object of the present invention is to form a diamond layer on the surface of a substrate with good adhesion, and when the obtained diamond-coated member is used as a grinding tool, a polishing tool, etc. It is an object of the present invention to provide a method capable of manufacturing a diamond-coated member which can remarkably improve the accuracy of a processed surface.

[0015]

The invention according to claim 1 for solving the above-mentioned problems is the IVA of the periodic table.
Having on its surface a solid solution layer made of at least one selected from the group consisting of carbides, nitrides and carbonitrides of two or more metals selected from the group consisting of metals belonging to group III, group VA and group VIA A diamond coating member having a base material and a diamond layer formed on the solid solution layer, wherein the invention according to claim 2 is the group IVA or the group VA of the periodic table. And VIA
Substrates containing two or more metals selected from the group consisting of metals belonging to Group I, or Group IVA, Group V of the Periodic Table
A substrate having a coating layer containing at least one metal selected from the metals belonging to Group A and Group VIA is heat-treated at 1,000 to 1,600 ° C. in an inert gas atmosphere, and the substrate surface 4. A method for producing a diamond-coated member, comprising forming a solid solution layer on the solid solution layer, and forming a diamond layer on the solid solution layer by a vapor phase method.
The invention described in (4) is a substrate containing two or more metals selected from the group consisting of metals belonging to Group IVA, Group VA and Group VIA of the Periodic Table, or Group IV of the Periodic Table.
A substrate having a coating layer containing at least one metal selected from the metals belonging to Group A, Group VA and Group VIA is used in an inert gas atmosphere at 1,000 to 1,600.
A diamond coating characterized in that a solid solution layer is formed on the surface of a base material by heat treatment at ℃, the solid solution layer is subjected to cobalt removal treatment, and then a diamond layer is formed on the solid solution layer by a vapor phase method. A method for producing a member, wherein the invention according to claim 4 is a group containing two or more metals selected from the group consisting of metals belonging to Group IVA, Group VA and Group VIA of the Periodic Table. Material, or I of the Periodic Table
A substrate having a coating layer containing at least one metal selected from metals belonging to the VA group, the VA group and the VIA group is 1,000 to 1,60 in an inert gas atmosphere.
A diamond characterized by forming a solid solution layer on the surface of a substrate by heat treatment at 0 ° C., smoothing the surface of the solid solution layer, and then forming a diamond layer on the solid solution layer by a vapor phase method. It is a method of manufacturing a covering member.

The diamond-coated member of the present invention will be described in detail below along with its manufacturing method. (1) Diamond-Coated Member The diamond-coated member of the present invention is the IVth component of the periodic table.
Substrate having on its surface a solid solution layer consisting of at least one selected from the group consisting of carbides, nitrides and carbonitrides of two or more metals selected from the metals belonging to Group A, Group VA and Group VIA. And a diamonds layer formed on the solid solution layer.

As will be described later, since the solid solution layer is provided on the substrate and the diamond layer is formed on the surface of this solid solution layer, the diamond-coated member of the present invention can be easily peeled from the substrate. Absent.

When the diamond-coated member of the present invention is manufactured by the method of the present invention in which the solid solution layer is subjected to the cobalt removal treatment, when the diamond-coated member is used as a working tool such as a cutting tool, it is possible to obtain a high degree of machining during processing. It can be an excellent tool having a diamond layer having extremely high adhesion, which does not easily peel even with temperature.

When the diamond-coated member of the present invention is manufactured by the method of the present invention in which the solid layer is subjected to surface smoothing treatment, when the diamond-coated member is applied to a working tool such as a cutting tool, It can be a tool with excellent processing characteristics that can finish the processed surface of the member with high surface accuracy.

Substrate The material of the substrate is determined by how the solid solution layer existing on the surface is formed.

The solid solution layer can be formed by heating the base material to change the surface of the base material itself, and on the surface of the base material, a group IVA of the periodic table,
It can be formed by forming a film of a metal belonging to Group VA and Group VIA or at least one selected from carbides, nitrides, and carbonitrides thereof on the surface of the base material and heating.

A. When a solid solution is formed by alteration of the base material
As the base material in the former case, it is necessary to deposit the solid solution component from the inside of the base material on the surface of the base material, and therefore, IVA, Group IVA, Group VA and Group VIA of the periodic table (IUPAC) are required.
It is preferable to use a cemented carbide or cermet containing two or more metals selected from the metals belonging to the group.

Specific examples of the tungsten carbide based cemented carbide include W such as WC, W-WC, WC-C and W-WC-C.
-C system, WC-Co, WC-Co-W, WC-Co-
C, W-Co system such as WC-Co-WC, WC-TaC
-Co, W-Ta-Co such as WC-TaC-Co-C
System, WC-TiC-Co, WC-TiC-Co, WC-
W-Ti-Co system such as TiCN-Co, WC-TaC-
W-Ti- such as Co and WC-TiC-TaC-Co-C
Cemented carbides such as Ta-Co-C type and WC-Nb-Co can be mentioned. The tungsten carbide based cemented carbide can be obtained from tungsten carbide, tantalum carbide, titanium carbide, etc. as described above. Examples of the tungsten carbide based cemented carbide used in the present invention include Ti, Co, Ta and M.
Those containing metals such as o, Cr and Ni are preferable. Note that these cemented carbides may contain carbon called "free carbon".

In the present invention, among the tungsten carbide type cemented carbide used as the base material, specific examples of preferable compositions are WC-TiC-Co, WC-TaC-Co,
WC-TiC-TaC-Co, WC-Co, and WC-
Cemented carbide of Nb-Co can be mentioned.

As the cemented carbide having the composition of WC-TiC-Co, tungsten carbide is 50 to 95% by weight, preferably 70 to 94% by weight, and titanium carbide is 1 to 30% by weight, preferably 2 to 20% by weight. And cobalt 2 to 20% by weight, preferably 4 to 10% by weight.

As a cemented carbide having a composition of WC-TaC-Co, tungsten carbide is 80 to 93% by weight, preferably 85 to 92% by weight, and tantalum carbide is 1 to 20% by weight, preferably 2 to 10% by weight. And 3 to 10% by weight, and preferably 4 to 6% by weight of cobalt.

As the cemented carbide having the composition of WC-Co, 90 to 98% by weight of tungsten carbide, preferably 9
Mention may be made of those containing 4 to 97% by weight and cobalt 2 to 10% by weight, preferably 3 to 6% by weight.

As the above-mentioned tungsten carbide, those used in conventional tools and the like can be used. Specifically, WC, WCx (where x is a positive real number other than 1, and is usually This x is a number greater than 1 or less than 1.) Stoichiometric compounds and non-stoichiometric compounds, or other elements such as oxygen bonded to these,
Those that have been replaced or invaded can be mentioned. Of these, WC is usually particularly preferably used. These may be used alone or in combination of two or more, or may be used as a mixture of two or more, a composition with a solid solution, and the like.

The titanium carbide is not particularly limited, and those used for producing ordinary alloys can be used. Specifically, TiC and TiCy (where y represents a positive real number other than 1 and usually y is 1
It is a number greater than or less than one. ), A stoichiometric compound and a non-stoichiometric compound, or a compound in which another element such as oxygen is bound, substituted or invaded. Of these, usually TiC
Are particularly preferably used.

The tantalum carbide is not particularly limited, and those used for producing ordinary alloys can be used. Specifically, TaC, TaCz (where z is a positive real number other than 1, and normally z is 1
It is a number greater than or less than one. ), A stoichiometric compound and a non-stoichiometric compound, or a compound in which another element such as oxygen is bound, substituted or invaded. Among these, usually TaC
Are particularly preferably used. The cobalt is not particularly limited, but a simple metal can be preferably used.

The tungsten carbide, the titanium carbide,
The tantalum carbide and the cobalt do not need to be particularly pure, and may contain impurities as long as the objects of the present invention are not impaired. For example, the tungsten carbide may contain a trace amount of excess carbon, excess metal, impurities such as oxides, and the like.

As the cermet used in the present invention,
For example, Ti, W, Mo, Cr, Ta, Nb, V, Z
Co, Ni, C on carbides and nitrides such as r and Hf
A cermet material containing a metal such as r, Mo or Fe as a sintering aid can be mentioned, and any material commonly known as a cermet material can be used without particular limitation.

Specific examples include WC, Mo ₂ C and Cr _3.
C ₂ , TaC, NbC, VC, TiC, ZrC, Hf
C, TaN, NbN, VN, TiN, ZrN, HfN,
Ta (C, O), Ti (C, O), Ti (N, O),
(W, Ti) C, (W, Ta, Ti) C, (W, Ta,
Nb, Ti) C, Ti (C, N), Ti (C, N,
O), (Ti, Zr) C, (Ti, Zr) (C, N), etc., contains Co and / or Ni as a sintering aid, and Cr, Mo, Fe, etc. in addition to Co and / or Ni. You can list the things that you did.

If the cermet is expressed differently from the above, the following description is also possible. That is, as the cermet that can be used in the present invention, Ti
WC, TaC and TiN are added to C and Ni is used as a binder phase.
Or Mo added, for example TiC-TaC-
Ni, TiC-TaC-Mo, TiC-TaC-Ni-
Mo, TiC-TiN-Ni, TiC-TiN-Mo,
TiC-TiN-Ni-Mo, TiC-TiN-TaC
-WC-Ni, TiC-TiN-TaC-WC-Mo,
TiC-TiN-TaC-WC-Ni-Mo, TiN-
TaN-Ni, TiN-TaN-Mo, TiN-TaN
-Ni-Mo, TiC-TaN-Ni, TiC-TaN
-Mo, TiC-TaN-Ni-Mo, TiC-Ni,
TiC-Mo, TiC-Ni-Mo, TiC-Ni, T
iC-Mo, TiC-Ni-Mo, TiC-TaN-N
i, TiC-TaN-Mo, TiC-TaN-Ni-M
o etc. can be mentioned. Note that these may contain other elements or their carbides.

Among these, titanium carbide, tungsten carbide and titanium nitride cermets are preferably used. Particularly preferred are TiC, TiN, and T.
A cermet material using Ni, Co, or Mo as a sintering aid for iCN or the like can be given.

No matter which cemented carbide or cermet is used, the solid solution in the present invention is formed by exposing the metal to be solid-solved, which will be described later, on the surface of the substrate. Preferably contains a component which forms a solid solution.

As the base material, a commercially available one can be used. Further, when a commercially available product is used, the base material can be obtained by a method such as sintering after the components are blended in an appropriate ratio.

Prior to sintering, together with the above ingredients,
If necessary, an auxiliary binder containing paraffin, stearic acid, camphor, etc. as a main component may be contained.
The sintering method is not particularly limited and can be performed according to a conventionally known sintering method.

In the sintering method, each of the above components can be used in the form of powder, fine powder, ultrafine particles, whiskers, or other various shapes, but the average particle size is Usually, fine particles or ultrafine particles having a size of 0.05 to 4 μm, preferably 1 to 3 μm, whiskers having an aspect ratio of about 20 to 200, and the like can be preferably used.

The sintering temperature is usually 1,200 to 1,
600 ° C, but in some cases 1,300-1,6
00 ° C or 1,300 to 1,550 ° C or 1,
It is suitable to set it in the range of 350 to 1,550 ° C.
The sintering time is usually 0.5 hours or more, preferably 1 to
It is suitable to set it within the range of about 2 hours.

There is no particular limitation on the shape of the substrate used for producing the diamond-coated member. The base material can be, for example, previously formed into a desired shape upon sintering and then sintered, or after the sintering, if necessary, processed into a desired shape to obtain the diamonds of the present invention. It can be used as a base material for a covering member.

B. Forming a coating layer of specific components on the surface of the substrate
In this case, the coating formed on the surface of the substrate is at least one metal selected from metals belonging to Group IVA, Group VA and Group VIA of the Periodic Table or a metal thereof. carbide,
If it is a nitride and / or a carbonitride and the coating layer can be transformed into a solid solution layer by heating the substrate and the coating layer together, the substrate is necessary for forming the solid solution layer. It does not have to be formed by different components.

On the other hand, the coating layer formed on the surface of the base material is at least one metal selected from the metals belonging to Group IVA, Group VA and Group VIA of the Periodic Table or its carbide, nitride and / or Or when it is carbonitride,
The base material is such that the solid solution layer defined in the present invention can be formed by heating the components and the components of the coating layer,
The material of the base material is appropriately selected. In this case, by heating, for example, the WC component in the base material diffuses and moves to the surface of the base material to form the solid solution layer defined in the present invention.

The base material when the base material itself is denatured by heating to form a solid solution layer, and the base material when a specific coating layer is formed on the surface of the base material and the solid solution layer is formed by heating The raw materials may overlap each other. That is, the base material is used to form a solid solution layer by modifying the base material itself by heating to form a base material, form a specific coating layer on the surface of the base material, and heat the base material. It is also possible to form a solid solution layer with the coating layer and the components in the substrate. Therefore, when exemplifying the base material when forming the solid solution layer by forming a specific coating layer on the surface of the base material, and exemplifying the base material when forming the solid solution layer by modifying the base material itself. Although it will be duplicated, the following is a specific example.

That is, this base material is not particularly limited, and generally known various kinds and compositions can be used. For example, W, Mo, Cr, Co,
Ni, Fe, Ti, Zr, Hf, Nb, Ta, Al,
Cemented carbides composed of one or more metals such as B, Ga, Si, etc., and cemented carbides of various compositions consisting of one or more of these metals and carbon, nitrogen, oxygen and / or boron, etc. Class (specifically, for example, WC, W-
WC, WC-C, WC system such as W-WC-C, Co-C
System, Co-WC, Co-W-WC, Co-WC-C, C
o-W-WC-C or the like of the Co-WC system, T such as TaC _x
a-C system, TiC system such as TiC, MoC _x, Mo-M
oC _x, MoC _x -C system, and the like MoC system, S such as SiC
i-C system, Fe-FeC _x system, etc. FeC system, Al ₂ O
Al—Fe—O system such as _3- Fe system, Ti—Ni—C system such as TiC—Ni system, Ti—Co—C system such as TiC—Co system
System, BN system, B ₄ C-Fe system or the like of Fe-B-C system, Ti
Ti-N type such as N type, Al-N type such as AlN _x type, Ta
N _x system or the like of the Ta-N system, WC-TaC-Co-C system, etc. of the W-Ta-Co-C system, WC-TiC-Co-C system, etc. of the W-Ti-Co-C system, WC TiC-TaC-Co-
C-based W-Ti-Ta-Co-C-based, W-Ti-C-
N-type, W-Co-Ti-C-N type, etc.) can be mentioned. Among these, as a particularly preferable example, for example, a WC-based cemented carbide suitable for a cutting tool or the like (specifically, for example, JIS B
Use classification symbols P01, P10, P2 in 4053
0, P30, P40, P50 and other P series, M10,
M series such as M20, M30, M40, K01, K1
Cemented carbide chips for cutting tools such as K series such as 0, K20, K30 and K40, cemented carbides for drawing dies such as V series such as V1, V2 and V3, for centers, cutting tools, etc. W-Co-C type cemented carbide such as WC-Co type such as chip, W-Ti such as WC-TiC-TaC-Co type
-Ta-Co-C type cemented carbide, or those in which a part of Ta is changed to Nb) and the like. In addition, these may contain elements other than the above and additional components. The material and shape of the cemented carbide used may be appropriately selected depending on the purpose of use and the like. In addition to the above cemented carbide, the cermet described above can also be used as the material of the base material.

B-1. Coating layer formed on substrate surface The coating layer formed on the substrate surface is a periodic table (IU
PAC) Group IVA metals, in particular Ti, Zr, H
f, a metal belonging to the group VA, especially V, Nb, Ta, and a metal belonging to the group VIA, especially at least one metal selected from the group consisting of Cr, Mo and W, or a carbide or nitride thereof. And / or carbonitrides are used.

Among these, metal titanium, titanium nitride, titanium carbide and titanium carbonitride are more preferable, and metal niobium, niobium nitride, niobium carbide and niobium carbonitride are more preferable. These may be used in one kind, or may be used in various compositions of two or more kinds.

As the titanium nitride, for example, Ti
N, or those represented by TiN _x , TiN-Ti, Ti-N and the like can be mentioned. Examples of the titanium carbide include TiC or Ti
_{C x, TiC-C, TiC} -Ti, TiC-TiC,
Examples thereof include those represented by Ti-C and the like. Examples of the titanium carbonitride include TiCN,
_{TiC · TiN, TiC X · TiN} x, TiC · TiN
-C, TiC / TiN-Ti, TiC / TiN-Ti-
Those represented by C, Ti-N-C and the like can be mentioned.

That is, the titanium coat is usually preferably represented by Ti, TiN, TiC or TiCN, but may be composed of two or more of these, and further, one or two of these may be used. More than seed, T
The i, C and / or N components may be contained in excess. Further, the titanium-containing coating layer may contain other elements or components other than Ti, C and N within a range not impairing the object of the present invention.

As a method for forming the coating layer on the surface of the cemented carbide base material, a method generally used,
For example, a commonly used ion plating method, sputtering method, or the like can be adopted.

The thickness of the coating layer is not particularly limited, but is usually 100 to 50,000 Å, preferably 1,
It is selected from the range of 000 to 30,000Å so that a solid solution layer having a desired thickness can be obtained. This film thickness is 100Å
If less than 5, the effect of the intermediate layer is difficult to expect,
If it exceeds 0Å, internal stress may occur in the intermediate layer itself.

-Solid solution layer- Whether the substrate itself is altered or the coating layer formed on the surface of the substrate is altered, the formed solid solution layer is a Group IVA of the Periodic Table (IUPAC). ,
At least one selected from the group consisting of carbides, nitrides, and carbonitrides of two or more metals selected from the metals belonging to Group VA and Group VIA.

When the "solid solution" is composed of, for example, two kinds of metals, the general formula M ¹ _A1 M ² _A2 C and the general formula M ¹ _A1 M ²
It can be expressed by _A2 N or general formula M ¹ _A1 M ² _A2 CN.

However, M ¹ and M ² are, respectively, Group IVA (Ti, Zr, Hf), Group VA (V, Nb, Ta) and Group VIA (Cr, M) of the Periodic Table (IUPAC).
o, W) are different metals selected from each other, and A1
, A2 are positive real numbers. In addition, even when it is composed of three or more kinds of metals, M ¹ _A1 M ² _A2 M ³ _A3 M ⁴ _A4
... it can be expressed as M ⁿ _An.

For example, qualitatively explaining the state of M ¹ _A1 M ² _A2 C, M ² atom penetrates between crystals to the place where M ¹ atom and C atom form a constant crystal structure. , M
It can be said that by replacing ^one atom, a solid-phase solution is formed.

This solid solution can be easily determined by the X-ray diffraction method. This solid solution has a cross section of EDA
X (official name: Energy Dispersive Analysis of X-ray
The composition and distribution of the solid-dissolved metal atoms can be confirmed by analyzing in (s). And the EDA
According to X, it is recognized that the concentration of the solid solution metal of this solid solution changes from the surface of the base material to the inside of the base material. As the metal that can be used for the solid solution, specifically, W, Ti, Ta, Mo, Nb, Cr,
V, Zr, and Hf can be mentioned.

The composition of the solid solution is not particularly limited, and depending on the number of metals in solid solution, one metal is 10 to 90 atomic%, preferably 40 to 10% of all the metals.
It is preferable that the content is 80 atom% and the balance is other metal.
When the content of one metal is less than 10 atom% or more than 90 atom%, the adhesion to the diamond layer may be insufficient. Specifically, when the base material is a WTiC system, W is 10 to 90 atom%, Ti is 10 to 90 atom%, and when the substrate is a WTiTaC system, W is 10 to 60 atom%, Ti is 40 to 80 atom%. , Ta is 10 to 30 atomic%
Are preferred.

The roughness Ra of the surface of the solid solution layer (also referred to as the surface of the substrate) is usually 0.05 to 1.5 μm, preferably 0.1 to 1.0 μm. When the surface roughness Ra of the solid solution layer is larger than the above value, the adhesion to the diamonds layer is rather decreased, and when it is smaller than the above value, the adhesion to the diamonds layer is also decreased. There is.

The thickness of the formed solid solution layer is preferably uniform and thin. If it is thick, it tends to be brittle. The thickness of the solid solution layer is usually 0.1 μm or more, preferably 0.5 to 30 μm, and more preferably 1 to 10 μm. The thickness when the solid solution layer is porous, in particular,
It is preferably 0.1 to 40 μm. Here, the thickness of the solid solution layer can be determined as follows. That is, the thickness of the porous layer can be determined by cutting the base material having the solid solution layer with a diamond wheel and observing the cut cross section with an SEM.

It is preferable that the composition of the solid solution layer continuously transitions to the composition of the substrate, rather than forming a clear interface with the substrate body. Further, it is preferable that the solid solution layer covers the entire surface, but an uncoated portion not covered with the solid solution layer may exist on the surface of the base material as long as the adhesion is not impaired.

(2) Method for manufacturing diamond-coated member The above-mentioned diamond-coated member is basically selected from the group consisting of metals belonging to Group IVA, Group VA and Group VIA of the periodic table. A base material containing two or more kinds of metals, or a base material having a coating layer containing at least one metal selected from metals belonging to Group IVA, Group VA and Group VIA of the periodic table, A heat treatment step of forming a solid solution layer on the surface of a substrate by heat treatment at 1,000 to 1,600 ° C. in an inert gas atmosphere, and diamonds forming a diamond layer on the solid solution layer by a vapor phase method. It is manufactured through a layer forming process. However,
In the present invention, a cobalt removal treatment step and / or a surface smoothing treatment step may be inserted between the heat treatment step and the diamond layer formation step. Hereinafter, each step will be described in detail.

Heat Treatment Step In this step, the surface of the base material itself is altered by heating the base material to a predetermined temperature in a predetermined atmosphere, or a specific coating layer is formed on the surface of the base material. Then, by heating to a predetermined temperature in a predetermined atmosphere, a solid solution is formed by the interaction between the specific coating layer and the substrate.

The base material when the surface of the base material itself is altered to form a solid solution is as described above, and a specific coating layer is formed on the surface of the base material and then heat-treated. The base material and the coating layer for forming the solid solution are as described above. The heat treatment for heating the base material itself to change the surface layer of the base material is performed by heating the surface of the base material under a constant pressure in an inert gas atmosphere.

As the above-mentioned inert gas, argon gas,
Examples thereof include rare gases such as helium gas, neon gas, and xenon gas, or nitrogen gas. Among them, argon gas can be particularly preferably used. Further, when a gas that reacts with the base material such as oxygen gas is mixed in the inert gas, these react with the base material. Therefore, in the inert gas, an active gas such as oxygen gas is used. Is desirable to be removed as much as possible.

The above-mentioned pressure is slightly different depending on the kind of the base material, but in general, it is usually atmospheric pressure or 3,
The pressure is not more than 000 atm, preferably 5 to 3,000 atm, and particularly preferably 1,000 to 3,000 atm. If the pressure is lower than atmospheric pressure, the surface of the substrate is not improved to the desired state. Also, the pressure is 3,000
Even if the pressure exceeds 0 atm, no further effect can be obtained compared to the effect obtained at 3,000 atm.

The above-mentioned temperature is slightly different depending on the kind of the base material, but it is generally 1,000 to 1,600.
℃ is preferred, in some cases 1,200-1,600
C. or 1,300-1,450.degree. C. is preferable. Generally, when the temperature is out of the above range, the surface of the substrate is not improved to a desired solid solution layer.

The heat treatment time cannot be generally stated because it depends on the temperature conditions, but it is usually 1 minute to 500 minutes.
Although it is a minute, depending on the case, it is 15 minutes to 300 minutes or 60 minutes to 300 minutes. If the heat treatment time is less than 1 minute, the surface modification of the substrate will be insufficient. Further, when the heat treatment time exceeds 500 minutes, the modification of the surface proceeds too much, resulting in an increase in irregularities on the surface of the substrate and a risk of deforming the substrate, which is not preferable. Note that the heat treatment can be performed by an appropriate method such as plasma heating, light irradiation, energization, laser heating, or electrolysis.

When a specific coating layer is formed on the surface of the substrate and then heat treatment is carried out, the heating temperature is usually 1,000 to 1,600 ° C., but depending on the case, , 1,200-1,600 ° C or 13
It is 00-1,550 degreeC. The atmosphere for the heat treatment is an inert gas such as argon, helium or nitrogen gas. The pressure during the heat treatment is normal pressure or 3,
It is appropriately selected from the range of 5 to 3,000 atm under pressure of not more than 000 atm. These atmospheric gases and pressures are appropriately determined according to the metal species in the coating layer.

The heat treatment time cannot be generally stated because it depends on the temperature conditions, but it is usually 1 minute to 500 minutes.
Minutes are preferred, but in some cases 15 minutes to 3
In some cases, 00 minutes or 60 to 300 minutes may be preferable. When the heat treatment time is less than 1 minute, modification of the coating film becomes insufficient. Further, if the heat treatment time exceeds 500 minutes, the same inconvenience as described above occurs, which is not preferable.

In any case, the heat treatment can be carried out by an appropriate method such as plasma heating, irradiation with light, energization, laser heating, electrolysis and the like. By this heat treatment, a group IVA of the periodic table (IUPAC),
A solid solution layer is formed of at least one selected from the group consisting of metals belonging to Group VA and Group VIA or their carbides, nitrides and carbonitrides.

Cobalt Removal Treatment Step In this cobalt removal treatment step, a catalyst for decomposing or converting diamonds formed on the solid solution layer into other carbon compounds when forming the diamond layer in the diamond layer forming step is used. A metal species having such a function as Co or Ni is removed from the solid solution layer. If a diamond layer with improved adhesion is simply formed on the solid solution layer, the cobalt removal treatment step may be omitted.
You may proceed to the following diamonds layer formation process. on the other hand,
It is preferable to carry out this cobalt removal treatment step when manufacturing a diamond-coated member as a processing tool in which the diamond layer does not easily peel off from the base material even at high temperatures during processing.

In any case, examples of the treatment performed in the cobalt removal treatment step having such a function include etching treatment with acid and etching treatment with plasma.

The acid is not particularly limited, but examples thereof include nitric acid, sulfuric acid, hydrochloric acid, hydrofluoric acid and the like. In addition, one of the above acids can be used alone, or a plurality of types of acids can be used in combination. Among the above acids, a mixed acid of nitric acid and hydrofluoric acid and a mixed acid obtained from hydrogen fluoride and nitric acid are particularly preferable.

As an example of the acid etching treatment, the case of using a mixed acid of nitric acid and hydrofluoric acid or a mixed acid obtained from hydrogen fluoride and nitric acid will be described in detail below. However, the acid etching treatment in the present invention is not limited to this.

Hydrogen fluoride itself can be used as hydrogen fluoride when preparing a mixed acid obtained from hydrogen fluoride and nitric acid, or in the form of hydrofluoric acid which is an aqueous solution of hydrogen fluoride. It can also be used. In the case of using the above mixed acid, in the mixed acid obtained from hydrogen fluoride and nitric acid, the hydrogen fluoride content is usually 5 to 50 mol%, assuming that hydrogen fluoride is not decomposed. It is preferably 10 to 40 mol%. The nitric acid concentration in this mixed solution is usually 5 to 65 mol%, preferably 15 to 60 mol%. When hydrogen fluoride and nitric acid are contained in the mixed acid within the above range,
A diamond film having high adhesion can be formed on the solid solution layer treated with such a mixed acid. In order to contain hydrogen fluoride within the above range, when hydrofluoric acid is used, it is 10 to 50%, preferably 2%.
Hydrofluoric acid containing 0-46% hydrogen fluoride is preferred. As nitric acid, nitric acid having a concentration of 30 to 70%, particularly 30 to 61% is preferable. From a practical point of view, as a mixed acid obtained from hydrogen fluoride and nitric acid,
A mixture consisting essentially of hydrofluoric acid and nitric acid is preferable, and a mixture formed by mixing other inorganic acids such as sulfuric acid may be used if necessary. When a mixture consisting essentially of hydrofluoric acid and nitric acid is adopted, it is preferable to adjust the respective concentrations of hydrofluoric acid and nitric acid so that the contents of hydrogen fluoride and nitric acid are as described above.

As the etching treatment with an acid in the present invention, various methods such as a method of immersing the substrate in the acid and a method of spraying the acid on the surface of the solid solution layer can be adopted. In short, it suffices if the predetermined surface of the solid solution layer on which the diamond film is to be formed can be brought into contact with the acid.

The temperature of the etching treatment with the acid is not particularly limited, but, for example, when the above mixed acid is used, it is usually preferably 20 to 100 ° C., particularly 50 to 9 ° C.
5 ° C is preferred. If the treatment temperature is lower than 20 ° C,
It may take time to etch the surface of the solid solution layer, or Co may not be sufficiently etched. If the treatment temperature is higher than 100 ° C., the etching of the surface of the solid solution layer progresses violently, which deteriorates the controllability.

The time for the acid etching treatment is not particularly limited as long as the etching is sufficiently performed. For example, when the above-mentioned mixed acid is used, it is usually 0.5.
Seconds to 300 seconds are preferable, and 1 second to 120 seconds is particularly preferable. If the treatment time is shorter than 0.5 seconds, the etching treatment may be insufficient. On the other hand, if it is longer than 300 seconds, the etching treatment may proceed excessively and the adhesion may be lowered.

The pressure of the acid etching treatment is not particularly limited. For example, when the above mixed acid is used, it may be performed under pressure. The pressure is usually preferably 1 to 5 atmospheres of pressure, and more preferably 2 to 5 atmospheres of pressure.

In the plasma etching treatment, for example, an inert gas such as argon or helium, a fluorocarbon, a carbon compound, a nitrogen gas, an oxygen gas, or a mixture thereof may be used.
Among them, especially argon or carbon dioxide 60
A mixed gas of 90% to 40% hydrogen gas and nitrogen gas are preferable.

The method of plasma conversion is not particularly limited, and various plasma processing methods such as a plasma conversion method used for a general vapor phase synthesis method of diamond or a diamond film can be applied. Specifically, for example, microwave plasma CVD method, high frequency plasma C
The VD method, the hot filament method, the ECR method and the like, or a combination method thereof and the like can be mentioned. Among these, the microwave plasma CVD method and the high frequency plasma CVD method are particularly preferable. Further, if the same CVD method as that used in the vapor phase synthesis of diamond, which will be described later, is adopted, it is convenient in terms of device configuration.

The reaction conditions for the etching treatment with plasma may be those conventionally used. For example, the processing pressure is 10 to 100.
A range of torr is preferred. When the pressure is higher than the above range, the controllability of the treatment is poor, and when it is low, the treatment takes time. The temperature of the surface of the solid solution layer is 500 to 1,1.
Within the range of 00 ° C, preferably 700 to 900 ° C.
When the temperature is higher than the above range, the controllability of the treatment is poor and the reproducibility is poor, and when the temperature is low, the treatment takes a long time. The processing time is 1 minute to 200 minutes, preferably 60 minutes.

In the present invention, the above-described etching treatment can remove the active metal such as Co existing on the surface of the solid solution layer. therefore,
It is possible to improve the adhesion between the base material and the diamond film, and when the diamond-coated member is used as a processing tool, it is effective that the diamond layer deteriorates or peels off due to the high temperature during processing. To be prevented.

Surface smoothing treatment step This surface smoothing treatment step aims to reduce the surface roughness of the solid solution layer and thereby reduce the surface roughness of the diamond layer formed on the solid solution layer. . When the surface roughness of the diamonds layer is reduced, when the diamonds-coated member is used as a processing member such as a grinding tool, a cutting tool, or a polishing tool, the processed surface of the counterpart workpiece can be made extremely smooth. Therefore, it becomes possible to improve the precision of the machined surface. Therefore, the diamond-coated member manufactured through this surface smoothing process can be used as a processing tool capable of precision processing and precision finishing.

The surface smoothing treatment step is not particularly limited as long as it includes a treatment operation capable of smoothing the surface of the solid solution layer, and specifically includes grinding, lapping, polishing, Processing operations such as chemical etching, electrochemical etching (electrolytic polishing), laser etching and the like can be included.

Examples of the lapping method include a method of grinding the surface of the solid solution layer using abrasive grains, and examples of the abrasive grains include diamond slurry and silicon carbide slurry. . Further, for example, the following electrolytic polishing can be performed.

In the above electropolishing, the substrate is the positive electrode,
The counter electrode is provided so that the counter electrode becomes the negative electrode, and the surface of the solid solution layer is electrolytically polished. The material of the electrode is not particularly limited as long as it does not generate a substance that inhibits the surface of the substrate during electropolishing, for example, gas, and is not particularly limited, and examples thereof include stainless carbon.

The voltage in the electropolishing is usually 2-1.
0V is preferable, and 3 to 10V is particularly preferable. When the voltage is lower than 2V, the polishing rate is low and it is inefficient. Further, when the voltage is higher than 10 V, the polishing rate becomes too high, the controllability is poor, and polishing may be performed more than necessary.

The electric current in the electropolishing is preferably 0.01 to 5 A / cm ² per unit area, and particularly preferably 0.1 to 1 A / cm ² . When the current per unit area is less than 0.01 A / cm ² , the polishing rate is low and the efficiency is poor. When the current per unit area is more than 5 A / cm ² , the polishing rate becomes too high and the controllability deteriorates.

The treatment time in the electropolishing cannot be unconditionally determined depending on the shape of the base material, the magnitude of the electric current, etc., but it is preferably 0.1 to 60 minutes, particularly 1 to 30 minutes. Minutes are preferred. The electrolytic solution in the electrolytic polishing is not particularly limited,
For example, a mixed solution of hydrochloric acid and hydrogen peroxide, an aqueous nitric acid solution and the like can be mentioned.

In the present invention, no matter what treatment operation is performed, the surface roughness Ra of the treated solid solution layer is increased.
Is usually 0.01 to 1.0 μm, preferably 0.05 to
It is preferable to perform surface smoothing treatment so that Rmax is 0.3 to 3 μm at 0.4 μm.

Generally, depending on the film quality of the diamond layer and the conditions for synthesizing the diamond layer, the surface roughness Ra (s) of the solid solution layer for synthesizing the diamond layer and the diamond layer formed on the surface are Ra (s). Surface roughness Ra (d)
, And Ra (d) ≈k · Ra (s) (k is usually 1 to
10, mainly 1 to 3). Therefore, Ra
The smaller the value of (s), the surface roughness R of the diamond layer
The value of a (d) can be reduced, and a diamond-coated member having an excellent finished surface roughness can be obtained.

However, in the method of the present invention, by performing the heat treatment step, the surface roughness Ra of the substrate is increased.
(S) is 10 compared with the surface roughness of the base material before the formation of the solid solution layer.
It will be about twice as big. Therefore, the surface smoothing treatment described above is applied to the Ra before the diamonds are synthesized.
By setting the value of (s) within the above range, as a result,
An excellent diamond-type layer having a small Ra (d) can be formed.

In the present invention, the thickness of the solid solution layer after the surface smoothing treatment is preferably uniform and thin, and is usually 0.1 μm or more, preferably 0.5 to 30 μm, more preferably 1 to 10 μm. . As described above, in the present invention, the surface of the substrate forming the diamond layer can be smoothed by performing the surface smoothing treatment described above, so that a diamond-coated member having excellent finished surface roughness can be produced. be able to. Therefore, it is possible to prevent the work material from being welded to the diamond coating member when cutting or working the work material or the work member, and to prolong the life of the coating member.

In the present invention, after the above-mentioned surface smoothing treatment is carried out, this substrate is usually washed with pure water,
dry. After washing with pure water, washing with an organic solvent such as acetone may be performed.

Diamond layer forming step In this diamond layer forming step, on the solid solution layer formed by the above solid solution forming step, or
Further, diamonds are synthesized on the solid solution layer that has undergone the cobalt removal treatment step and / or the surface smoothing treatment step.

The diamonds referred to herein include diamond and diamond-like carbon partially containing diamond-like carbon, in addition to diamond.

Various methods have been conventionally known as the method for forming the diamond layer, and there is no particular limitation.
In the method of the present invention, as shown below, a vapor phase synthesis method using a carbon source gas can be preferably adopted.

Examples of the carbon source gas include paraffin hydrocarbons such as methane, ethane, propane and butane; olefin hydrocarbons such as ethylene, propylene and butylene; acetylene hydrocarbons such as acetylene and allylene; butadiene. Diolefin hydrocarbons such as allene; cyclopropane, cyclobutane, cyclopentane,
Alicyclic hydrocarbons such as cyclohexane; aromatic hydrocarbons such as cyclobutadiene, benzene, toluene, xylene, and naphthalene; ketones such as acetone, diethyl ketone, benzophenone; alcohols such as methanol and ethanol; other oxygen-containing compounds Hydrocarbons; amines such as trimethylamine and triethylamine; other nitrogen-containing hydrocarbons; carbon dioxide gas, carbon monoxide, carbon peroxide and the like. Among these, preferred are paraffin hydrocarbons such as methane, ethane and propane, alcohols such as ethanol and methanol, ketones such as acetone and benzophenone, amines such as trimethylamine and triethylamine, carbon dioxide and carbon monoxide. Yes,
Carbon monoxide is particularly preferable.

Incidentally, these may be used alone,
It is also possible to use a mixture of two or more compounds. Further, in the usual case, these are used by mixing with an active gas such as hydrogen or an inert gas such as helium, argon, neon, xenon or nitrogen. The concentration of the carbon source gas differs depending on the type of gas used and cannot be determined unconditionally, but is usually 0.5 to 50% by volume, preferably 1 to 20% by volume. When the carbon source gas concentration is high, the diamond-like carbon content in the diamond film tends to increase.

For the formation of the diamond layer, various known diamond thin film vapor phase synthesis methods such as a CVD method, a PVD method, or a combination thereof can be used. Among them, usually E
Various hot filament methods including the ACVD method, various direct current plasma CVD methods including the thermal plasma method, microwave plasma CVD methods including the thermal plasma method, and the like can be preferably used.

The conditions for forming the diamond layer are not particularly limited, and the reaction conditions usually used in the above vapor phase synthesis method can be applied. For example, the reaction pressure is usually preferably 10 ⁻⁶ to 10 ³ Torr, and particularly preferably 1 to 800 Torr. When the reaction pressure is lower than 10 ^-6 Torr, the formation rate of the diamond layer may be slow. Also 10 ³
When it is higher than Torr, there is no more effect than the effect obtained at 10 ³ Torr.

The surface temperature of the base material cannot be unconditionally specified because it depends on the means for activating the raw material gas and the like, but it is usually 300 to 1,200 ° C., preferably 450 to 1,000. It is better to set it within the range of ° C.
If this temperature is lower than 300 ° C, the formation of the crystalline diamond-like layer may be insufficient. Also,
When the temperature exceeds 1,200 ° C., the formed diamond layer is likely to be etched.

The reaction time is not particularly limited, and it is preferable to appropriately set it so that the diamond layer has a desired thickness in accordance with the formation rate of the diamond layer.
The thickness of the diamond layer formed on the surface of the base material cannot be uniformly set because it depends on the purpose of use of the diamond-coated member and the like, but in the case of a tool, it is usually 1 μm or more, preferably 3 to 50 μm or more. Is appropriate. If the diamond layer is too thin, it may not be possible to sufficiently cover the surface of the substrate. In this way, when the diamond thin film is formed on the surface of the intermediate layer, the carbon source gas of the raw material reacts with the metal of the intermediate layer, the metal of the intermediate layer is carbonized, and then diamond is generated. Therefore, the adhesion between the intermediate layer and the diamond thin film is improved.

As described above, according to the method of the present invention,
A diamond coated member can be manufactured. When the diamond-coated member obtained as described below is used as a cutting tool, the cutting edge portion of the cutting tip is shaped.

For this shaping, the diamond coating deposited on the flank of the cutting tip is partially or entirely scraped off with a diamond grindstone, and the angle of the ridgeline between the surface of the cutting tip and the flank is 70 to 100 degrees. Process so that it has a sharp cutting edge. By shaping in this way, a cutting tip having excellent cutting performance can be obtained.

[0107]

EXAMPLES The present invention will be described in more detail below with reference to examples of the present invention and comparative examples thereof, but the present invention is not limited to these examples. In the following Examples and Comparative Examples, the adhesion between the diamond layer and the substrate, the surface roughness, and the roughness of the finished surface were evaluated as follows.

Evaluation method of adhesion of diamond layer (
(Dentation method) Using a Rockwell hardness tester, the indenter is pushed into the base material from the diamond layer surface of the test piece (diamond layer-coated base material) under the conditions of a load of 60 kgf and a holding time of 30 seconds, and the indenter The peeled area of the diamond-like layer was determined by the method, and the quality of the adhesion of the diamond-like layer to the substrate (large or small) was evaluated by the magnitude of the measured value.

Using a stylus type surface roughness meter,
Evaluation was made based on the result of measurement in the section of mm. Further, confirmation of the solid solution layers formed in the following examples and comparative examples was performed as follows.

Confirmation of solid solution layer The solid solution layer was subjected to X-ray analysis. The lattice constants measured by X-ray analysis of the substrate surface in each example are shown in Tables 1 and 2. The lattice constant of WC is 4.214Å
Is. Since the lattice constants shown in Table 1 and Table 2 are different from those of WC, it can be seen that a solid solution is formed. Further, by SEM, it was confirmed that the contrast of the surface in the cross-sectional photograph of the base material having the heat-treated surface was different from that inside the base material, and its presence was also confirmed from the surface composition by EDAX.

(Examples 1 to 7) Size 1 shown in Table 1
A 2.7 mm × 12.7 mm square cemented carbide base material was heat-treated under the respective solid solution layer forming conditions shown in Table 1. For Examples 1 to 7, a diamonds layer was formed under the following conditions on the surface of the substrate on which the solid solution layer was formed by heat treatment,
Each diamond coated member was obtained. The thickness of the formed diamonds layer was approximately 25 μm in all cases.

Conditions for synthesizing diamond layer Raw material gas: mixed gas of CO (15% by volume) and H ₂ (85% by volume) Gas flow rate: 10 sccm Synthesis conditions: reaction pressure 40 Torr, substrate temperature 900 ° C.,
Synthesis time 10 hours Synthesis method (source gas excitation method): Microwave plasma CV
Method D microwave frequency: 2,45 GHz (350 W) It was confirmed by Raman spectrum that the formed film was diamond. For each diamond-coated member (test piece) obtained above, the adhesion between the diamond layer and the substrate was evaluated by the above-mentioned indentation method. The results are shown in Table 1.

(Examples 8 to 19) The cutting tool tip shown in Table 2 was formed on the surface of a cemented carbide base material having a size of 12.7 mm x 12.7 mm square by a sputtering method.
A thin layer having a thickness of 1.5 μm composed of the coating shown in FIG. Next, this was heat-treated under the respective solid solution layer forming conditions shown in Table 2. Here, K01, K10, K20 and P10 used for the respective cemented carbide base materials indicate the use classification symbols of the cemented carbide chips based on JIS B 4053, and these cemented carbides are respectively ,
It has the composition shown below.

Composition of cemented carbide base material K01: WC-Co system (W: 91% by weight, Co: 5% by weight, C: 4% by weight) K10: WC-Co system (W: 87% by weight, Co : 7 wt%, C: 6 wt%) cemented carbide K20: WC-Co type (W: 87 wt%, Co: 8 wt%, C: 5 wt%) cemented carbide P10: WC-TiC- Cemented Carbide of TaC-Co system (W: 50% by weight, Ti: 16% by weight, Ta: 17% by weight, Co: 9% by weight, C: 8% by weight) of a base material having a solid solution layer formed by heat treatment. Diamond layers were formed on the surface in the same manner as in Examples 1 to 7 to obtain diamond-coated members. In addition,
The thickness of the formed diamond layer was about 25 μm in each case. It was confirmed by Raman spectrum that the formed film was diamond. For each diamond-coated member (test piece) obtained above, the adhesion between the diamond layer and the substrate was evaluated by the above-mentioned indentation method. The results are shown in Table 2.
Shown in.

(Comparative Examples 1 to 5) In Comparative Examples 1 to 4, the size of the cutting tool tip was 12.7 mm × 1.
On the surface of a 2.7 mm square cemented carbide substrate, for Comparative Example 5 on the surface of a cemented carbide substrate having the composition shown in Table 1,
A diamond-like layer was formed under the same conditions as those in the above-described examples without forming a solid solution layer. Adhesion of the diamond layer was evaluated in the same manner as in the above-mentioned examples. The results of Comparative Example 5 are shown in Table 1 and the results of Comparative Examples 1 to 4 are shown in Table 2.

Example 20 As a base material, a tungsten carbide based cemented carbide (W: 84.9% by weight, Ti: 2.3% by weight, Ta: 1.6% by weight, Co: 4.9% by weight, C:
Size of 12.8 mm x 12.8 consisting of 6.3% by weight)
mm-square chip based on JIS B 4053 (SPG
N422) was used. The surface of this base material was heat-treated for 1 hour at 2,000 atm and 1,350 ° C. under an argon gas atmosphere. Next, this heat-treated base material is impregnated with a solution in which hydrofluoric acid (concentration 46%) and nitric acid (concentration 61%) are mixed at a mixing ratio of 1: 1 to etch the surface of the base material. Then, Co on the surface of the base material was removed. After that, a diamond-based layer was formed using a microwave plasma CVD method in the same manner as in Example 1 except that the raw material gas was changed to a mixed gas of CO (20% by volume) and H ₂ (80% by volume). Synthesized on the surface of wood. The diamond layer thus obtained had a thickness of 25 μm.

It was confirmed by Raman spectrum that the formed film was diamond. For each diamond-coated member (test piece) obtained above, the adhesion between the diamond layer and the substrate was evaluated by the above-mentioned indentation method. As a result, the peeled area of the diamond layer was extremely small and the adhesion was large.

(Example 21) A titanium nitride-based cermet (TiN: 59% by weight, Ni: 6% by weight, Co:
9% by weight, MoC: 26% by weight)
A diamond layer was synthesized on the substrate in the same manner as in. It was confirmed by Raman spectrum that the formed film was diamond. For each diamond-coated member (test piece) obtained above, the adhesion between the diamond layer and the substrate was evaluated by the above-mentioned indentation method. As a result, the peeled area of the diamond layer was extremely small and the adhesion was large.

(Example 22) A diamonds layer was synthesized on a substrate in the same manner as in Example 20 except that the treatment with nitrogen plasma was carried out for 20 minutes instead of the etching treatment. It was confirmed by Raman spectrum that the formed film was diamond. For each diamond-coated member (test piece) obtained above, the adhesion between the diamond layer and the substrate was evaluated by the above-mentioned indentation method. As a result, the peeled area of the diamond layer was extremely small and the adhesion was large.

(Examples 23 to 26) As a base material, WC-
TiC-Co based cemented carbide (WC: 92.5% by weight, Ti
C: 2.5% by weight, Co: 5% by weight) or WC-Ta
A C-Co based cemented carbide (WC: 90% by weight, TaC: 5% by weight, Co: 5% by weight) was used. This substrate was subjected to a heat treatment with a heater under an atmosphere of argon gas at 2000 atm under each of the solid solution layer forming conditions shown in Table 1. Table 3 shows the thickness of each of the formed solid solution layers.

Then, the surface of the formed solid solution layer was subjected to a lapping process using diamond slurry having a grain size of 0 to 1 μm as abrasive grains. The surface roughness Ra (s) of the solid solution layer after lapping was evaluated by the surface roughness evaluation method. The results are shown in Table 3. Next, a diamond layer was synthesized on the surface of the lapped solid solution layer in the same manner as in Example 1. It was confirmed by Raman spectrum that the formed film was diamond.

With respect to each diamond-coated member thus obtained, the adhesion between the diamond layer and the substrate was evaluated by the indentation method described above. In addition, the surface roughness Ra (d) of each diamond layer was evaluated by the above-described surface roughness evaluation method. The results are shown in Table 3.

(Examples 27 to 29) A solid solution layer was formed in the same manner as in Example 23 using each of the base materials shown in Table 3. Table 3 shows the thickness of the obtained solid solution layer. Next, the obtained solid solution layer was subjected to electrolytic polishing under the following conditions.

Conditions of Electropolishing Electrolyte: Mixed solution of 1,000 ml of 10% HCl aqueous solution and 25 ml of H ₂ O ₂ Cathode: SUS304 plate Voltage: 3V Electrolysis time: 5 seconds Surface roughness of electropolished solid solution layer Table 3 shows the result of measurement by the same method as in Example 23.

Then, a diamonds layer was synthesized on the surface of the electrolytically polished solid solution layer in the same manner as in Example 23 to produce a diamonds-coated member. For each of the obtained diamond-coated members, the adhesion between the diamond layer and the substrate and the surface roughness Ra (d) of the diamond layer were evaluated in the same manner as in Example 23. The results are shown in the table.

For reference, the surface roughness Ra (s) of the solid solution layer on the surface of the substrate before the lapping treatment in Example 23 and the layer when the diamonds layer was formed without lapping treatment The surface roughness Ra (d) is shown in Table 3 as Reference Example 1.

[0127]

[Table 1]

[0128]

[Table 2]

[0129]

[Table 3]

[0130]

According to the present invention, since the base material has the solid solution layer on its surface and the diamond layer is formed on the surface of the solid solution layer, it has a diamond layer with significantly improved adhesion to the base material. A diamond-coated member can be provided. This diamond coated member,
It is preferably used as a processing tool such as a cutting tool, a polishing tool, and a grinding tool.

Further, according to the present invention, when the diamond-coated member is manufactured, when the solid solution layer is formed and then the cobalt removal treatment is performed, the diamonds deposited on the solid solution layer during the formation of the diamond layer are not decomposed or decomposed. It is possible to provide a method of manufacturing a diamond-coated member that can efficiently form a diamond layer without deterioration. According to the method for manufacturing the diamond-coated member, since the amount of metal species such as cobalt that contributes to the decomposition or deterioration of the diamond is significantly reduced on the surface of the solid solution layer, the method for manufacturing the diamond-coated member is described. The diamond-coated member obtained by the above can be an excellent tool in which the diamond layer is not deteriorated or peeled off even when it is used as a processing tool even at a high temperature during processing.

Furthermore, according to the present invention, since the surface of the solid solution layer is smoothed, the surface of the diamond layer formed on the smooth surface of the solid solution layer can be smoothed. It is possible to provide a diamond-coated member that can significantly improve the surface accuracy of the machined surface of the mating workpiece when the diamond-coated member used as a machining tool is used.

Claims (4)

[Claims] 1. A metal selected from the group consisting of carbides, nitrides and carbonitrides of two or more metals selected from the group consisting of metals belonging to Group IVA, Group VA and Group VIA of the Periodic Table. A diamond-coated member, comprising: a base material having a solid solution layer of at least one kind on the surface thereof, and a diamond layer formed on the solid solution layer. 2. A base material containing two or more metals selected from the group consisting of metals belonging to Group IVA, Group VA and Group VIA of the Periodic Table, or Group IVA of the Periodic Table.
A substrate having a coating layer containing at least one metal selected from the group III, VA and VIA metals in an inert gas atmosphere at 1,000 to 1,600 ° C.
A method for manufacturing a diamond-coated member, which comprises heat-treating to form a solid solution layer on the surface of a substrate, and forming a diamond layer on the solid solution layer by a vapor phase method. 3. A base material containing two or more metals selected from the group consisting of metals belonging to Groups IVA, VA and VIA of the Periodic Table, or IVA of the Periodic Table.
A substrate having a coating layer containing at least one metal selected from the group III, VA and VIA metals in an inert gas atmosphere at 1,000 to 1,600 ° C.
A member for coating diamonds, characterized in that a solid solution layer is formed on the surface of a base material by heat treatment with, and the solid solution layer is subjected to cobalt removal treatment, and then a diamond layer is formed on the solid solution layer by a vapor phase method. Manufacturing method. 4. A base material containing two or more metals selected from the group consisting of metals belonging to Group IVA, Group VA and Group VIA of the Periodic Table, or Group IVA of the Periodic Table.
A substrate having a coating layer containing at least one metal selected from the group III, VA and VIA metals in an inert gas atmosphere at 1,000 to 1,600 ° C.
A diamond coating characterized in that a solid solution layer is formed on the surface of a substrate by heat treatment with, a smoothing treatment is applied to the surface of the solid solution layer, and then a diamond layer is formed on the solid solution layer by a vapor phase method. A method of manufacturing a member.