JP2003171785A - Method of removing hard surface film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily remove only a hard surface film consisting of an intermetallic compound in a coated member in which the surface of a diamond film is provided with the hard surface film. <P>SOLUTION: End mills 24 in which the surface of a diamond film is provided with a hard surface film are arranged at the inside of a reaction furnace 12. After that, the pressure in the reaction furnace 12 is reduced to about 900 to 1,300 Pa. Simultaneously, gaseous hydrogen is introduced therein at a flow rate of about 0.1 to 0.2 L/min, and also, microwaves are introduced into the reaction furnace 12 by a microwave generator 14. Thus, the gaseous hydrogen is made into plasma, and the end mills 24 are heated to about 800 to 1,000°C, so that, based on the difference in thermal expansion between the diamond film and the hard surface film, the hard surface film is separated from the diamond film, and is removed. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for removing a hard surface coating made of an intermetallic compound provided on a diamond coating.

[0002]

2. Description of the Related Art As a cutting tool such as an end mill, a cutting tool, a tap, and a drill, a diamond-coated tool obtained by coating the surface of a cemented carbide substrate with a diamond coating is described, for example, in Japanese Patent Laid-Open No. 148623/1995. However, when an iron-based material is processed by using such a diamond-coated tool, there is a problem that the diamond coating reacts with iron and wears or peels off early. Therefore, the applicant of the present application has proposed in Japanese Patent Application No. 2001-342213 previously filed to provide a hard surface coating made of a hard intermetallic compound on the diamond coating.

[0003]

By the way, since the coating member having such a diamond coating is expensive,
When a hard surface film made of an intermetallic compound is worn or peeled off by use, it is desired to remove only the hard surface film and to newly provide a hard surface film on the diamond film for reuse.

The present invention has been made in view of the above circumstances, and an object of the present invention is to easily remove only a hard surface coating while leaving a diamond coating.

[0005]

In order to achieve such an object, the first invention provides a diamond coating and a hard surface coating made of a hard intermetallic compound on the diamond coating. Of the covering member,
A method of removing only the hard surface coating leaving the diamond coating, wherein the coating member is heated, and the hard surface coating is formed into a diamond coating based on a thermal expansion difference between the diamond coating and the hard surface coating. It is characterized by separating from.

A second invention is the method for removing a hard surface coating of the first invention, wherein the coating member is a microwave plasma CV.
The coating member is placed in the reaction furnace of the D apparatus, and the inside of the reaction furnace is depressurized to a predetermined pressure and a predetermined gas is introduced to generate plasma by microwaves, thereby covering the coating member with a temperature of 800 to
It is characterized by heating to 00 ° C. to separate the hard surface coating from the diamond coating.

A third invention is the method for removing a hard surface coating according to the second invention, wherein (a) the pressure in the reaction furnace is 500 to 30.
Within a range of 00 Pa, (b) the predetermined gas is hydrogen gas or oxygen gas, and the introduction flow rate into the reaction furnace is 0.01
Within the range of up to 0.5 L / min, (c) the microwave output power is within the range of 1 to 5 kW.

[0008]

According to such a method for removing a hard surface film, the hard surface film is separated from the diamond film based on the difference in thermal expansion between the diamond film and the hard surface film by heating the coating member. Therefore, as compared with the case where the diamond film is removed by polishing or chemical treatment, only the hard surface film can be easily removed without scratching the diamond film.

In the second aspect of the invention, the microwave plasma C widely used for the coating of diamond film, etc.
By using a VD apparatus to form plasma by microwaves and heating the coating member to 800 to 1000 ° C., the hard surface coating is separated from the diamond coating, so existing equipment is used. The hard surface film can be removed more easily and at low cost.

In the third invention, the pressure in the reaction furnace is 500 to
In the range of 3000 Pa, the flow rate of hydrogen gas or oxygen gas introduced into plasma is 0.01 to 0.5 L / min.
In the range, the microwave output power is in the range of 1 to 5 kW, so that only the hard surface film can be satisfactorily removed while leaving the diamond film. Further, since hydrogen gas or oxygen gas is used, it is inexpensive and easy to handle.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION A coating member which is an object of the method of the present invention is provided with a diamond coating such as a cutting tool such as an end mill, a cutting tool, a tap or a drill, or another processing tool such as a rolling tool. In addition, various members having a hard surface coating made of a hard intermetallic compound on the diamond coating are possible.

The diamond coating is preferably provided by a vapor phase synthesis method such as a microwave plasma CVD method, a filament CVD method, an arc plasma CVD method, or an ionization vapor deposition method. For example, diamond-like carbon (DLC; Diam described in JP-A-5-65646).
ond-Like Carbon). Diamond-like carbon is an amorphous carbon having physical properties similar to diamond and has a Vickers hardness (Hv) of 1000-8.
It is about 000, not strictly a diamond,
A material having a hardness higher than that of a hard intermetallic compound such as TiC, for example, a material having a Vickers hardness (Hv) of about 5000 or more can be treated in the same manner as diamond.

As the base material on which the diamond coating is provided, a superhard material such as a superhard alloy such as cemented carbide or cermet, or a superhard non-alloy such as ceramics is preferably used to enhance the adhesion of the diamond coating. In addition, if necessary, an intermetallic compound or the like may be provided between the diamond film and the base material. The thickness of the diamond coating is
For example, the range of 5 μm to 25 μm is suitable, and 10 to 20
About μm is desirable.

As the intermetallic compound constituting the hard surface film, metals of the IIIb group, IVa group, Va group and VIa group of the periodic table of elements, for example, carbides such as Al, Ti, V and Cr, nitrides and charcoals are used. Nitride or a mutual solid solution of these is suitable,
Specifically, TiAlN, TiCN, TiCrN, Ti
N or the like is preferably used. Such a hard surface film,
For example, it is preferably provided by a PVD method such as an arc ion plating method or a sputtering method, but may be provided by another film forming method such as a plasma CVD method.

The above hard surface coating may have a single layer, but it may also be composed of two or more layers of intermetallic compounds. For example, TiN, which has excellent adhesion to diamond, is provided on the diamond coating in a thickness of, for example, about 0.2 to 0.5 μm, and TiN is formed thereon in a thickness of about 3 to 4 μm.
N, etc., or 0.2 to 0.5 μ
Various modes are possible, such as alternately and repeatedly providing TiN and TiAlN having a thickness of about m. Also,
The hard surface coating does not necessarily need to be provided so as to cover the entire diamond coating, but may cover only a part thereof.

In the second invention, the heating temperature of the covering member is 800
In the range of 1000 ° C. to 1000 ° C., in the third invention, the pressure in the reaction furnace is in the range of 500 to 3000 Pa, and the flow rate of hydrogen gas or oxygen gas introduced into plasma is 0.01 to 0.5.
Within the range of L / min, the output power of microwave is 1 to 5
Although it is within the range of kW, these are merely examples and can be appropriately changed according to the coating method of the diamond coating or the hard surface coating, the type of the hard surface coating, the thickness, and the like. The heating temperature of the covering member is the temperature of the surface of the covering member and can be measured with a radiation thermometer (radiation thermometer) or the like.

In the second invention, microwave plasma CVD is used.
An apparatus is used to heat the coating member by microwaves. However, in carrying out the first invention, another CVD apparatus or PVD apparatus for coating, or another processing container not related to coating, etc. It is also possible to use. Regarding the heating of the covering member, another heating method such as a resistance heater capable of heating up to about 800 to 1000 ° C. can be appropriately adopted.

When the diamond coating is worn or damaged by use, for example, Japanese Patent Laid-Open No. 2001-2001
By removing the diamond film by the method described in 295044, it is possible to reuse only the base material.

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic configuration diagram of a hard surface film removing apparatus 10 capable of satisfactorily removing a hard surface film according to the method of the present invention, which uses a microwave plasma CVD apparatus, and a diamond can be obtained by changing the kind of a supply gas. It can also be used for coating such as a coating. The hard surface coating removal device 10 is configured to include a reaction furnace 12 as a processing container, a microwave generator 14, a hydrogen gas supply device 16, and a vacuum pump 18.
A table 22 is provided in the cylindrical reaction furnace 12, and a plurality of end mills 24 provided with a hard surface coating 52 (see FIG. 2) to be removed are supported and mounted on a work support 26. Has become. The end mill 24 is a processing tool for cutting and corresponds to a covering member.

FIG. 2 is a view for concretely explaining the end mill 24, (a) is a front view seen from a direction perpendicular to the axis,
(b) is a cross-sectional view near the surface of the blade portion 44. This end mill 24 is a 4-flute square end mill and has a tool base 4
2 is made of a cemented carbide containing WC as a main component, and a shank and a blade portion 44 are integrally provided on the tool base 42 in the axial direction. The blade portion 44 is provided with an outer peripheral blade 46 and a bottom blade 48 as cutting edges, and the surface of the blade portion 44 is provided with a diamond coating 50 having a film thickness of about 20 μm and having a substantially complete diamond crystal structure, for example, a micro film. It is coated by a coating technique such as a wave plasma CVD method. Further, on the diamond coating 50, a hard surface coating 52 made of an intermetallic compound is provided on almost the entire area of the diamond coating 50 including the cutting edges of the outer peripheral blade 46 and the bottom blade 48. The hard surface coating 52 is formed on the diamond coating 50.
TiN layer 54 having a thickness of about 3 μm and the TiN layer 54
A TiAlN layer 56 having a thickness of about 4 μm provided on the
And is coated by a coating technique such as an arc ion plating method. The hatched portion in FIG. 1 (a) represents the diamond coating 50 and the hard surface coating 52 coated on the surface of the tool base 42.

The plurality of end mills 24 are arranged on the work support 26 with the blade portions 44 coated with the diamond coating 50 and the hard surface coating 52 facing upward. These end mills 24 are used products in which the hard surface coating 52 is worn or damaged by use, or defective products caused by defective coating of the hard surface coating 52 during manufacturing. The work support 26 is made of stainless steel.

The microwave generator 14 is a device for generating a microwave of, for example, 2.45 GHz. When the microwave is introduced into the reaction furnace 12, the hydrogen gas supply device 16 causes the inside of the reaction furnace 12 to flow. The hydrogen gas supplied to the end mill 24 is heated to plasma and the heating temperature is adjusted by controlling the electric power of the microwave generator 14. Through the observation window 30, a radiation thermometer is used to detect the heating temperature (surface temperature) of the blade portion 44 of the end mill 24, and the power of the microwave generator 14 is feedback-controlled so as to reach a predetermined heating temperature. To do. Further, a quartz glass plate 32 for observing the state of the end mill 24 and maintaining a vacuum state is provided in the upper portion of the reaction furnace 12.

The hydrogen gas supply device 16 comprises a gas cylinder filled with hydrogen gas, a flow rate control valve for controlling the flow rate, a flow meter, etc., and reacts hydrogen gas at a predetermined flow rate. Supply into the furnace 12. The vacuum pump 18 is for sucking the gas in the reaction furnace 12 to reduce the pressure, and the reaction furnace 12 detected by the pressure gauge 34 is used.
The motor current of the vacuum pump 18 is feedback-controlled so that the internal pressure value becomes a predetermined pressure value.

FIG. 3 shows such a hard surface film removing apparatus 1
After the hard surface coating 52 is removed by using 0, the tool base 42 coated with the diamond coating 50 is reused, and the hard surface coating 52 is newly coated on the diamond coating 50 to thereby end mill. 24
In the step S1, the hard surface film removing apparatus 10 is used to remove only the hard surface film 52 while leaving the diamond film 50. Specifically, after inserting the end mill 24 into the work support 26 and arranging it in the reaction furnace 12, the pressure in the reaction furnace 12 is reduced to about 900 to 1300 Pa by the vacuum pump 18 and the hydrogen gas supply device 16 is used. Hydrogen gas 0.1 to 0.2
It is introduced at a flow rate of about L / min, and the microwave generator 14 is operated at a power of about 2 kW to generate 2.45 GHz.
By introducing the microwave into the reaction furnace 12, the hydrogen gas is turned into plasma and the temperature of the blade portion 44 of the end mill 24 is heated to about 800 to 1000 ° C. This allows
Based on the difference in thermal expansion between the diamond coating 50 and the hard surface coating 52, the hard surface coating 52 is separated from the diamond coating 50 and removed.

In step S2, the end mill 24 from which the hard surface coating 52 has been removed in step S1 is taken out from the reaction furnace 12, and the debris and dust of the hard surface coating 52 adhering to the diamond coating 50 are washed and removed. To do. Then, in step S3, the hard surface coating 52 is recoated on the diamond coating 50 using a coating device such as an arc ion plating device (not shown).

Thus, in this embodiment, the end mill 24
If the hard surface coating 52 is worn or damaged, or if a defective product occurs due to defective coating of the hard surface coating 52 during manufacturing, after removing the hard surface coating 52 only, an expensive diamond coating Since the end mill 24 is manufactured by reusing the tool base material 42 having the remaining 50 and re-coating the hard surface coating 52, the tool base material 42 and the diamond coating 50 are effectively used, and the manufacturing cost is reduced. .

On the other hand, when the end mill 24 is heated in the reaction furnace 12, the hard surface coating 52 is separated from the diamond coating 50 on the basis of the difference in thermal expansion between the diamond coating 50 and the hard surface coating 52. Diamond coating 50 compared to the case of removing by chemical treatment or chemical treatment.
Only the hard surface film 52 can be removed easily and inexpensively in a short time without scratching.

Further, a microwave plasma CVD apparatus which is widely used for coating a diamond film is used as the hard surface film removing apparatus 10, and plasma is formed by microwaves to form the end mill 24 at 800 to 10-10.
By heating to 00 ° C., the hard surface coating 52 is separated from the diamond coating 50, so that the hard surface coating 52 can be removed more easily and at low cost using existing equipment.

The pressure in the reaction furnace 12 is 900 to 13
At about 00 Pa, the flow rate of hydrogen gas introduced is 0.1 to 0.2.
Since the microwave output power is about 2 kW at about L / min, only the hard surface coating 52 can be satisfactorily removed while leaving the diamond coating 50.

Since hydrogen gas is used for plasma heating, it is inexpensive and easy to handle.

The embodiments of the present invention have been described above in detail with reference to the drawings. However, these are merely embodiments, and the present invention includes various modifications and improvements based on the knowledge of those skilled in the art. Can be implemented in.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram illustrating an example of a hard surface film removing apparatus that can suitably perform the method of the present invention.

2A and 2B are views showing an example of an end mill from which a hard surface film is removed by the apparatus of FIG. 1, in which FIG. 2A is a front view and FIG. 2B is a cross-sectional view near the surface of a blade portion.

FIG. 3 is a diagram showing the end surface of the end mill shown in FIG.
It is a flowchart which shows the procedure at the time of manufacturing the end mill by re-coating a hard surface film.

[Explanation of symbols]

10: Hard surface film removing device (microwave plasma CVD
Equipment) 12: Reactor 24: End mill (Coating member) 50: Diamond coating 52: Hard surface coating

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C23C 16/02 C23C 16/02 F term (reference) 3C037 CC04 3C046 FF03 FF09 FF12 FF16 4K029 AA02 AA29 BA03 BA34 BA58 BA60 BB02 BB03 BC02 BD05 CA03 EA03 FA04 FA05 4K030 AA17 BA02 BA18 BA28 BA38 BB12 CA03 DA03 DA04 FA02 JA05 JA09 JA10 JA11 JA16 LA21 4K057 DA01 DB05 DB08 DB15 DD01 DE20 DG02 DG07 DG13 DM29 DN10

Claims (3)

[Claims] 1. A coating member provided with a diamond coating and a hard surface coating made of a hard intermetallic compound on the diamond coating, leaving only the diamond coating and leaving only the hard surface coating. Is a method of removing the coating member, a hard surface coating, characterized in that the hard surface coating is separated from the diamond coating based on the difference in thermal expansion between the diamond coating and the hard surface coating. Removal method. 2. A microwave plasma CV for covering the covering member.
The coating member is placed in the reaction furnace of the apparatus D, and the inside of the reaction furnace is depressurized to a predetermined pressure and a predetermined gas is introduced to generate plasma by microwaves to cover the covering member at 800 to 1000.
The method for removing a hard surface coating according to claim 1, wherein the hard surface coating is separated from the diamond coating by heating to ° C. 3. The pressure in the reaction furnace is 500 to 3000.
Within the range of Pa, the predetermined gas is hydrogen gas or oxygen gas, the flow rate of introduction into the reaction furnace is within the range of 0.01 to 0.5 L / min, and the output power of the microwave is 1 to 1. The method for removing a hard surface coating according to claim 2, wherein the hard surface coating is in the range of 5 kW.