JPH0673531A - Production of member coated with hard material - Google Patents

Abstract

PURPOSE:To produce a hard material coated member excellent in heat resistance, environment resistance, adhesion, etc., by applying heat treatment to the surface, to be coated, of a base material under a rare-gas atmosphere at a pressure not lower than atmospheric pressure at the time of forming a hard film composed essentially of cubic boron nitride on the base material composed of hard material. CONSTITUTION:A hard coating film composed essentially of cubic boron nitride is formed on a base material (cermet, etc.) composed of hard material. At this time, heat treatment is applied to the surface, to be coated, of the base material under the atmosphere composed of rare gas (helium, neon, etc.) and/or nitrogen gas, at a pressure (about 10 to 2000atm) not lower than the atmospheric pressure, at about 1100-1900 deg.C, for about 0.5-5hr. By this method, the hard material coated member excellent in heat resistance and environment resistance and having superior adhesion to the surface of the base material can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a hard material coated member, and more specifically, it contains cubic boron nitride as a main component, which is excellent in heat resistance, environment resistance and the like and has excellent adhesion. The present invention relates to a method for producing a hard material-coated member obtained by coating a hard coating film on a substrate.

[0002]

2. Description of the Related Art Conventionally, as a method for forming a cubic boron nitride film, Japanese Patent Laid-Open No. 55-
54564 discloses that "a boron layer is formed on the surface of a timepiece component by an ion plating method, and then a boron nitride layer is formed on the boron layer by a reactive ion plating method in an atmosphere of nitrogen gas. Forming ”method is described. In addition, JP-A-52-1
Japanese Patent No. 82699 discloses that a boron nitride film is formed on the surface of a throwaway chip by a high frequency ion plating method in a nitrogen gas atmosphere (Japanese Patent Application Laid-Open No. 52-82699, page 1, right). Column lines 7-17,
See lines 6-8). Japanese Unexamined Patent Publication No. 3-285062 discloses "Boron in a boron nitride thin film formed by irradiating a surface of a substrate with ions containing a nitrogen element at the same time as vapor deposition of a substance containing a boron element, alternately or after vapor deposition. A method is disclosed in which the ratio of the number of atoms to the number of nitrogen atoms is reduced intermittently or continuously (see claims).

However, in either method,
Excellent adhesion so that it can be used as a tool,
Moreover, a sufficiently high-purity cubic boron nitride film is not formed.

[0004]

SUMMARY OF THE INVENTION The present invention for solving the above-mentioned problems is intended to coat a base material made of a hard substance with a hard coating film containing cubic boron nitride as a main component. A method for manufacturing a hard material-coated member, characterized in that the surface is heat-treated under an atmosphere of a rare gas and / or a nitrogen gas under a pressure of atmospheric pressure or higher.

In the present invention, when a hard material is referred to,
The hardness is usually 90 or more when evaluated on the Rockwell hardness A scale. As a hard material suitable as a base material,
For example, cemented carbide, cermet, silicon nitride, composites mainly composed of silicon nitride, Al ₂ O ₃ , or IVA group IVA, VA and VIA.
Mention may be made of metals belonging to the group or metal compounds thereof.

The cemented carbide is not particularly limited,
Various commonly known types and compositions can be used, such as W, Mo, Cr, Co, Ni,
Cemented carbides consisting of one or more metals such as Fe, Ti, Zr, Hf, Nb, Ta, etc., consisting of one or more of these metals and carbon, nitrogen, oxygen and / or boron, etc. Cemented carbides of various compositions (specifically, for example, WC, W-WC, WC-C, W-WC-
WC system such as C, Co-C system, Co-WC, Co-W-
Co- such as WC, Co-WC-C, Co-W-WC-C
WC system, Ta-C system such as TaC _x , Ti-system such as TiC
C _{system, MoC x, Mo-MoC x} , MoC x -C systems such MoC system, Fe-FeC _x system, etc. FeC system, TiC
-Ni-based Ti-Ni-C-based, TiC-Co-based T, etc.
i-Co-C system, TiN type such as TiN system, TaN _x system and the like of the TaN system, WC-TaC-Co-C system, etc. of the W-T
a-Co-C-based, WC-TiC-Co-C-based WT
i-Co-C system, W-Ti-Ta-Co-C system such as WC-TiC-TaC-Co-C system, W-Ti-C-N system,
A wide variety of cemented carbides such as W-Co-Ti-CN system) can be mentioned. Among these, as a preferable example, for example, a WC-based cemented carbide suitable for a cutting tool or the like (specifically, for example, use classification symbols P01, P10, P20, P30 in JIS B4053,
P series such as P40, P50, M10, M20, M3
0, M40 and other M series, K01, K10, K20,
WC for K30, K40 and other K series cutting tools, etc., cemented carbide chips for V1, V2, V3 and other V series wire drawing dies, centers, cutting tools, etc. -Co-based W-Co-C cemented carbide, W
W-Ti-Ta-Co such as C-TiC-TaC-Co system
-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.

Among the above, preferable base materials are Group IVA, Group VA and Group V of the Periodic Table (IUPAC).
An example is a tungsten carbide based cemented carbide containing a metal belonging to Group IA and one or more metals selected from Si.

Specific examples of preferable tungsten carbide based cemented carbide include WC, W-WC, WC-C and W-WC-.
WC system such as C, WC-Co, WC-Co-W, WC-
W-Co system such as Co-C, WC-Co-WC, WC-
W-Ta- such as TaC-Co and WC-TaC-Co-C
Co system, WC-TiC-Co, WC-TiC-Co, W
W-Ti-Co system such as C-TiCN-Co, WC-Ta
WT such as C-Co, WC-TiC-TaC-Co-C
Cemented carbides such as i-Ta-Co-C system 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, and T.
Those containing a metal such as a, Mo, Cr and Ni are preferable.

In the present invention, among the tungsten carbide type cemented carbide used as the base material, specific examples of preferable compositions include WC-TiC-Co, WC-TaC-Co and WC-Co, WC-Nbc-. An example is a cemented carbide of Co. As a cemented carbide having a composition of WC-TiC-TaC-Co, 50 to 95% by weight of tungsten carbide, preferably 70 to 94% by weight, and titanium carbide 1 to
Having 30% by weight, preferably 2-20% by weight, tantalum carbide 1-20% by weight, preferably 2-10% by weight, cobalt 2-20% by weight, preferably 4-10% by weight. You can

As a cemented carbide having a 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.

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

As a cemented carbide having a 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 above-mentioned 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 generally 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, T
A cermet material that uses Ni, Co, or Mo as a sintering aid for iCN or the like can be given.

In addition to the above-mentioned cemented carbide, a ceramic sintered body such as silicon nitride or alumina can be used as the base material made of a hard material. The silicon nitride is not particularly limited as long as it has a basic structure in which nitrogen is coordinated with silicon 4 and nitrogen is coordinated with silicon 3.

Silicon nitride does not exist naturally, and for example, direct nitriding method, reduction / nitriding method, or vapor phase reaction (CVD)
Silicon nitride synthesized by a chemical reaction method such as a thermal decomposition method or a thermal decomposition method can be used as the base material of the present invention.

The synthesized silicon nitride is usually sintered when used as a substrate. For sintering silicon nitride, a sintering aid such as Y ₂ O ₃ or Al ₂ O ₃ is usually added. Many sintering aids do not form a solid solution in silicon nitride and remain at the grain boundaries, but Al ₂ O ₃ forms a solid solution in the grains even after sintering with silicon nitride, and Si-Al-O- An N-based solid solution is formed. Since this solid solution has a β-Si ₃ N ₄ structure, it is also called β-sialon. Therefore, in the present invention, the term "silicon nitride" is a concept including sialon. In the present invention, examples of sialon include β-sialon and α-thyron.

In general, silicon nitride does not have a single composition but contains a sintering aid in a proportion of several% to several tens% as described above. Although the microstructure of silicon nitride changes depending on the sintering method, the silicon nitride sintered body obtained by any of the sintering methods can be preferably used in the present invention.
Here, examples of the sintering method of silicon nitride include a reaction sintering method, a hot pressing method, an atmospheric pressure sintering method, a HIP method, a gas pressure sintering method, and a Post Sintering method,
Silicon nitride sintered by any of these methods can be used in the present invention.

As the composite containing silicon nitride, silicon nitride and a hard material such as TiC, TiN, W can be used.
A composite material with C, SiC, or the like can be given.

Al ₂ O ₃ includes α-alumina and γ-
Examples thereof include aluminas (η, γ, δ), θ-alumina, χ-alumina, κ-alumina, ρ-alumina. In addition to these, a ceramic sintered body such as SiC, AlN or B ₄ C can be used.

In the present invention, the α-alumina and the transition alumina can be used, and also, they can be used as a composite material of the alumina and the metal. As a composite material of alumina and metal, Al ₂
O ₃ -Cr system, Cr-Al ₂ O ₃ system (often chromium content than alumina), Al ₂ O ₃ -Fe system, Al ₂ O ₃ -
Examples include Co-based materials.

As the material of the base material in the present invention, there are group IVA, group VA and group V of the periodic table (IUPAC).
Metals belonging to Group IA or their metal compounds such as TiC, TiN, TiCN, TiO ₂ , ZrC, Hf
N, NbC, TaC, Cr ₂ C, WC, etc. can also be used. In the present invention, these metals or metal compounds and SiC, Al ₂ O ₃ , AlN, B ₄ C are used.
A material obtained by coating the surface of a material that is not hard but has heat resistance against the heating temperature during the heat treatment described below can also be used as the base material.

In the method of the present invention, when a hard coating film containing cubic boron nitride as a main component is coated on a substrate made of a hard material, the substrate is preliminarily exposed to a rare gas or nitrogen gas atmosphere. It is important to perform the heat treatment under a pressure higher than atmospheric pressure.

The heating atmosphere is an atmosphere consisting essentially of rare gases (helium, neon, argon, xenon, krypton), an atmosphere consisting essentially of nitrogen gas,
Alternatively, a mixed gas atmosphere of a rare gas and nitrogen gas may be used.

The pressure during the heat treatment may be at least atmospheric pressure, and preferably 10 to 2,000 atm.

The heating temperature is usually 1,100 to 1,
900 ° C., preferably 1,300 to 1,800 ° C. can be mentioned.

A heating time of about 0.5 to 5 hours is usually sufficient.

When the base material is heated to an appropriate temperature within the temperature range under the heating atmosphere and under the pressure, when the base material is formed of the cemented carbide or cermet, the base material is heated. When the solid solution layer is formed in the material surface layer portion and the base material is formed of ceramics such as Al ₂ O ₃ , crystals are coarsened and fine irregularities are formed in the base material surface layer portion. And the adhesion to the hard coating film containing cubic boron nitride as a main component are improved.

In the method of the present invention, the surface of the base material is subjected to the heat treatment, and then, for example, as follows.
A hard coating film containing cubic boron nitride as a main component is formed on the surface of the base material after the heat treatment.

As a raw material for forming a hard coating film containing cubic boron nitride as a main component, boron boron sources B and h are used.
_{-BN, B 2 N 6, H} 3 BO 3 and the like, as a nitrogen source N
₂ , NH _{3 and the} like can be mentioned.

The hard coating film is formed by, for example, a usual ion plating method using the above-mentioned raw material, plasma CVD.
Method, an ion beam deposition method, a method combining a plasma CVD method and laser irradiation, and the like.

For example, when the ion plating method is adopted, boron is placed in the reaction chamber as a boron source and 10 ^-4 To is obtained.
Nitrogen gas is introduced into the reaction chamber maintained at a reduced pressure of rr and heated to a range of 300 to 500 ° C., then nitrogen gas is introduced while maintaining a reduced pressure of 10 to 300 Torr and the boron is accelerated. By bombarding electrons and reacting boron ions generated by the bombardment of electrons with nitrogen, boron nitride is deposited on the surface of the base material.

According to the above reaction conditions, a hard coating film containing cubic boron nitride as a main component is formed on the surface of the base material.

The fact that the hard coating film is made of cubic boron nitride can be easily confirmed by observing the infrared absorption spectrum. That is,
Cubic boron nitride peak of TO folder was observed at 1,080cm ^-1, h-BN is 780 cm ^-1 and 1,400
Absorption peaks of LO foll and TO foll are observed near cm ^-1 .

The thickness of the hard coating film formed on the surface of the base material varies depending on the use of the hard material coating member. However, when this hard material coated member is used for a processing tool such as a cutting tool or a polishing tool, the thickness of the hard coating film is 1
The thickness of the hard coating film is 0 to 40 μm, and the thickness of the hard coating film is 1 to 10 when this hard material coating member is used for sliding parts.
μm.

[0042]

【Example】

(Example 1) A chip (12.7 mm x 12.7 mm) of a commercially available WC-TiC-TaC-Co cemented carbide (P10 type in JIS B4053) was placed at 2,000 at 1,350 ° C in an argon atmosphere. Heat treatment was performed for 1 hour. A hard coating film having a thickness of 5 μm and containing cubic boron nitride as a main component was formed on the chip after the heat treatment using an ion plating device to which an RF substrate bias was applied.

Quantitative analysis of this hard coating film by infrared absorption spectrum showed that the content of cubic boron nitride was 68.
% By weight.

When the adhesion of this hard coating film was evaluated by a scratch test, the film was not peeled off under a load of 20N.

Example 2 A Si ₃ N ₄ sintered body was heat-treated in an argon atmosphere at 2,000 atm and 1750 ° C. for 1 hour. Per Si ₃ N ₄ sintered body after the heat treatment, by performing the same processes as in Example 1, Si ₃
Cubic boron nitride as a main component on a N ₄ sintered body with a thickness of 5
A hard coating film of μm was formed.

Quantitative analysis of this hard coating film by infrared absorption spectrum revealed that the content of cubic boron nitride was 66.
% By weight.

When the adhesion of this hard coating film was evaluated by a scratch test, the film was not peeled off under a load of 20N.

(Comparative Example 1) A cubic boron nitride is used as a main component by using the same chip as in Example 1 except that the heat treatment is not performed. A hard coating film having a thickness of 65 μm was formed.

Quantitative analysis of this hard coating film by infrared absorption spectrum revealed that the content of cubic boron nitride was 65.
% By weight.

The hard coating film spontaneously peeled off several hours after the coating film was formed.

(Comparative Example 2) A cubic boron nitride was used as a main component by carrying out the same procedure as in Example 2 except that the same sintered body as in Example 2 was used and no heat treatment was performed. A hard coating film having a thickness of 1 μm was formed.

When this hard coating film was quantitatively analyzed by infrared absorption spectrum, the content of cubic boron nitride was 66.
% By weight.

The hard coating film spontaneously peeled off several hours after the formation of the coating film.

[0054]

EFFECTS OF THE INVENTION According to the present invention, a hard coating film having a cubic boron nitride as a main component, which is excellent in heat resistance and environment resistance, and has excellent adhesion to the surface of the base material, is made of a hard material. It is possible to provide a method for producing a hard material-coated member obtained by coating the above.

Claims (1)

[Claims] 1. When coating a hard coating film containing cubic boron nitride as a main component on a base material made of a hard material, the coated surface of the base material is exposed to an atmosphere of rare gas and / or nitrogen gas,
A method for producing a hard material-coated member, which comprises performing a heat treatment under a pressure equal to or higher than atmospheric pressure.