TWI557257B - The manufacturing method of the covering tool - Google Patents

Description

Method for manufacturing coated tool

The present invention relates to a method of manufacturing a coated tool which is used for, for example, a die for press working or forging, a cutting tool such as a saw blade, and a cutting tool such as a cutting tool such as a drill. Drilled carbon film (hereinafter also referred to as "DLC (diamond-like carbon) film).

When a material to be processed such as aluminum, copper, or resin is molded by a mold, there is a case where a part of the workpiece is attached to the surface of the mold, and a product such as scratches or damage is abnormal. In order to solve this problem, a coated mold in which a DLC film is formed on the surface of a mold is actually used. The DLC film (Tetrahedral amorphous carbon film: ta-C film) which does not substantially contain hydrogen is high in hardness and excellent in abrasion resistance, and thus is widely used in coated molds. However, a high-hardness DLC film substantially free of hydrogen is formed by arc ion plating using a graphite target, and a particle having a size of several micrometers called a droplet (graphite ball) ) It is inevitably mixed into the DLC film, and the surface roughness of the DLC film is deteriorated.

In order to solve such a problem, Patent Document 1 discloses that a filtered arc ion plating method having a mechanism for collecting droplets can be used to form a smooth and high-hardness DLC film substantially free of hydrogen. Prior art literature

Patent Document 1: Japanese Patent Laid-Open Publication No. 2008-297171

[Problems to be solved by the invention]

When formed by a filtered arc ion plating method as in Patent Document 1, a DLC film having a high hardness and a smooth surface state can be obtained. However, the DLC film having a high hardness tends to have insufficient adhesion, and if only the filtered arc ion plating method is applied, it is difficult to achieve satisfactory adhesion. Further, in order to further improve the durability of the coated tool in a severe use environment, it is required to make the DLC film of high hardness thicker. However, when the film formation time is prolonged in order to form a thick DLC film, the arc discharge is likely to be unstable, and it is difficult to form a high-density DLC film into a thick film while ensuring excellent adhesion.

The present invention has been made in view of the above circumstances, and relates to a method for producing a coated tool capable of forming a high-hardness DLC film into a thick film while ensuring excellent adhesion. [Means for solving the problem]

The present invention relates to a method of manufacturing a coated tool, which is a method of manufacturing a coated tool for forming a diamond-like carbon film on a surface of a substrate by a filtered arc ion plating method, comprising: a first step of applying the substrate The negative bias voltage is set to -2500 V or more and -1500 V or less, and a mixed gas containing hydrogen gas is introduced into the furnace to perform gas bombard treatment on the surface of the substrate; and a second step is performed at Introducing nitrogen into the furnace after the gas impact treatment, introducing a current into the graphite target to form a diamond-like carbon film on the surface of the substrate, and in the second step, including reducing the flow rate of the nitrogen gas And a step of increasing the current input to the graphite target.

Preferably, the diamond-like carbon film has a film thickness of 2.0 μm or more. Preferably, in the step of increasing the current input to the graphite target, the current input to the graphite target is increased by a total of 40 A or more. [Effects of the Invention]

According to the present invention, a high hardness DLC film having excellent adhesion can be formed into a thick film. Further, the film formation is stable, and a coated tool excellent in durability can be stably produced.

The inventors of the present invention have studied a method of making the film thickness of a high-hardness DLC film excellent in adhesion good. Further, it has been found that in the filtration arc ion plating method, it is important to control the gas impact treatment performed on the substrate before the formation of the DLC film, the gas atmosphere in the furnace when the DLC film is formed, and the current input in the graphite target. A method of manufacturing a coated tool of the present invention. Hereinafter, the details of the present invention will be described.

The present invention can use a conventionally known filtered arc ion plating apparatus. By applying the filtered arc ion plating method, the droplets contained in the inside of the film are reduced to have a smooth surface state, and a DLC film having a high hardness of 50 GPa or more having substantially no hydrogen indentation can be formed. In particular, when a T-type filter arc ion plating apparatus is used, a smoother and higher hardness DLC film can be formed, which is preferable.

In order to improve the abrasion resistance of the coated tool, the DLC film of the present invention preferably has a nanoindentation hardness of 50 GPa or more. Further, it is preferably 55 GPa or more, and more preferably 60 GPa or more. More preferably, it is 70 GPa or more. On the other hand, when the hardness of the DLC film is too high, the residual compressive stress becomes too high, and the adhesion to the substrate may be lowered. Therefore, the nanoindentation hardness is preferably 100 GPa or less. The nanoindentation hardness of the DLC film is further preferably 95 GPa or less.

The nanoindentation hardness is a plastic hardness when the probe is press-fitted into a sample (DLC film) to be plastically deformed, and a load-displacement curve is obtained from the press-in load and the press-in depth (displacement) to calculate the hardness. Specifically, using a nanoindentation device manufactured by ELIONIX Co., Ltd., a measurement condition of a press load of 9.8 mN, a maximum load holding time of 1 second, and a load removal speed of 0.49 mN/sec. The hardness measured at 10 points on the surface of the film was determined based on the average value of 6 places other than the two places having large values and two values.

A high-density DLC film having a nanoindentation hardness of 50 GPa or more tends to have an extremely high internal stress and lacks adhesion to a substrate. As a method for improving the adhesion from the prior art, a technique of providing an intermediate film having a hardness lower than that of the DLC film has been proposed. However, according to the study of the present inventors, in the case where an intermediate film such as a metal, a carbide or a nitride is interposed between the substrate and the DLC film, the DLC film preferentially peels off from the surface defect of the intermediate film as a starting point. Therefore, it was confirmed that it was insufficient for improving the adhesion. Therefore, in the present invention, the gas impact treatment performed on the substrate before the formation of the DLC film is investigated so that the adhesion is not impaired even if the DLC film is directly formed directly above the substrate.

In the present invention, as a first step, a mixed gas containing hydrogen gas is introduced into the furnace to perform a gas impact treatment on the surface of the substrate. According to the study by the present inventors, it has been confirmed that when a conventional gas collision treatment using argon gas is performed, oxygen is present in a large amount at the interface between the film and the substrate, and the adhesion is lowered. The oxygen present at the interface is mainly caused by the oxide film originally formed on the surface of the substrate, and is a residual element which cannot be completely removed by the gas impact treatment using argon gas. Therefore, in the present invention, a mixed gas containing hydrogen gas is introduced into the furnace (vacuum chamber) to perform a gas impact treatment on the surface of the substrate. By performing a gas impact treatment on the surface of the substrate using a mixed gas containing hydrogen gas, the oxide film on the surface of the substrate is reacted with hydrogen ions to be reduced, thereby sufficiently removing the oxide film and the surface dirt, and forming it directly above the substrate. The adhesion of the DLC film is improved.

The mixed gas containing hydrogen is preferably a mixed gas containing 4% by mass or more of hydrogen with respect to the total mass of argon and hydrogen. If the amount of hydrogen gas is less than 4% by mass, there is a case where it is difficult to remove the oxide film by a gas impact treatment using a mixed gas. Further, it is preferable to use a mixed gas of 5% by mass or more of hydrogen, and more preferably a mixed gas of 7% by mass or more of hydrogen. Further, it is more preferable to use a mixed gas containing 10% by mass or more of hydrogen. However, in the case of a mixed gas having a hydrogen gas content of more than 30% by mass, the effect of removing the oxide film and the surface dirt by the gas impact treatment is constant (even if the hydrogen gas concentration is increased to a level or higher, the effect is not improved). tendency. Therefore, it is preferred to use a mixed gas of hydrogen gas of 30% by mass or less. Further, it is preferable to use a mixed gas of hydrogen of 25% by mass or less. Furthermore, it is more preferable to use a mixed gas of hydrogen gas of 15% by mass or less.

In the gas impact treatment using the above-described mixed gas, the negative bias applied to the substrate is set to -2500 V or more and -1500 V or less. If the negative bias applied to the substrate is greater than -1500 V (the positive side of -1500 V), since the impact energy of the gas ions is low, the effect of removing the oxide of the oxide film and the surface becomes small, and the substrate and the substrate are The adhesion of the high hardness DLC film tends to decrease. Further, when the negative bias applied to the substrate is less than -2500 V (on the negative side of -2500 V), there is a case where the plasma is liable to become unstable and cause abnormal discharge. If an abnormal discharge occurs, an abnormal discharge (arc) trace is formed on the surface of the tool, so that the surface of the tool is uneven. Further, the negative bias applied to the substrate is preferably -2400 V or more, and more preferably -2300 V or more. Further, the negative bias applied to the substrate is preferably -1600 V or less, and more preferably -1700 V or less. In order to sufficiently remove the oxide on the surface of the substrate, it is preferred to carry out a gas impact treatment using a mixed gas for 60 minutes or more. More preferably, it is carried out for 70 minutes or more. The upper limit of the time of the gas impact treatment is preferably appropriately adjusted depending on the shape or material of the substrate. However, when the gas impact treatment by the mixed gas is 180 minutes or longer, the effect of removing the oxide film and the surface dirt by the gas impact treatment tends to be constant (the effect is not improved to the extent that the effect is not improved). Therefore, it is preferable to carry out a gas impact treatment using a mixed gas for 180 minutes or less.

In the present invention, as a second step, nitrogen gas is introduced into the furnace after the gas impact treatment, and an electric current is supplied to the graphite target to form a DLC film on the surface of the substrate subjected to the gas impact treatment. The nitrogen-containing DLC film is formed in a state where the oxide film on the surface of the substrate is sufficiently removed by the gas impact treatment, whereby the residual compressive stress of the DLC film on the surface of the substrate is lowered, and the substrate and the DLC film can be further improved. The adhesion. In order to further reduce the residual compressive stress of the DLC film on the substrate side and further improve the adhesion, it is preferred that the flow rate of the nitrogen gas introduced into the furnace after the gas impact treatment is 5 sccm or more. When the flow rate of nitrogen gas is less than 5 sccm, there is a case where it is difficult to sufficiently obtain an effect of improving the adhesion. More preferably, it is set to 10 sccm or more. On the other hand, if the flow rate of the nitrogen gas introduced into the furnace after the gas impact treatment is excessively large, the content of nitrogen contained in the DLC film increases, the hardness of the film decreases, and the wear resistance is easily lowered, and the non-ferrous material is also added. In the case of processing, it becomes easy to melt. Therefore, the flow rate of nitrogen gas is preferably set to 60 sccm or less. More preferably, it is 50 sccm or less. More preferably, it is set to 40 sccm or less. When the flow rate of the nitrogen gas introduced into the furnace is too small with respect to the volume of the inside of the furnace (vacuum chamber), there is a case where it is difficult to sufficiently obtain the effect of improving the adhesion of the DLC film. Therefore, the volume (m ³ ) in the furnace/the flow rate (sccm) of the nitrogen gas introduced into the furnace is preferably set to 10 × 10 ^-2 (m ³ /sccm) or less. Further, it is preferably set to 5.0 × 10 ^-2 (m ³ /sccm) or less. Further, when the flow rate of the nitrogen gas introduced into the furnace with respect to the volume in the furnace is excessively large, it is easy to contain excessive nitrogen in the DLC film. Thus, the furnace volume (m ³⁾ / the flow rate of nitrogen introduced into the furnace (sccm) is preferably set to ^{0.1 × 10 -2 (m 3 /} sccm) or more. Further, it is preferably 1.0 × 10 ^-2 (m ³ /sccm) or more.

In the present invention, in the second step, a step of reducing the flow rate of nitrogen gas and applying a current to the graphite target to form a DLC film is provided. In order to improve the adhesion to the substrate, it is effective to introduce nitrogen gas to form a DLC film. However, if the nitrogen atom is excessively contained in the entire DLC film, the hardness is lowered. Further, in the case of processing a non-ferrous material, melting tends to occur. Therefore, in the present invention, the flow rate of nitrogen gas is reduced, and a current is introduced into the graphite target to form a DLC film to prevent excessive nitrogen gas from being contained in the entire DLC film. When the DLC film is formed by reducing the flow rate of nitrogen gas at the time of film formation, the DLC film on the substrate side contains a large amount of nitrogen atoms, and the residual compressive stress is lowered, and the adhesion to the substrate is improved, and the surface side DLC is improved. The content of nitrogen atoms in the film is small, and the wear resistance and the fusion resistance are improved. In the second step, it is preferred to form a DLC film while gradually reducing the flow rate of nitrogen gas introduced into the furnace. Further, it is preferred to finally stop introducing nitrogen gas and apply a current to the graphite target to form a DLC film. By forming the DLC film by stopping the introduction of nitrogen gas, it is preferable to form a DLC film having a higher hardness and less melting of the material to be processed on the surface in contact with other materials. In order to achieve a DLC film having a higher hardness and less melting of the material to be processed, it is preferable to finally introduce nitrogen gas and set the pressure in the furnace to 5 × 10 ^-3 Pa or less to form a DLC film. In the second step, a hydrocarbon gas such as acetylene may be introduced into the furnace to increase the hydrogen content of the DLC film on the substrate side. Further, after the first step, a hydrocarbon gas such as acetylene may be introduced into the furnace, and then the second step may be carried out.

In the present invention, in the second step, a step of increasing the current input in the graphite target to form a DLC film is provided. The inventors of the present invention have confirmed that in the formation of the DLC film by the filtration arc ion plating method, the surface of the graphite target has large irregularities and the arc discharge becomes unstable accompanying the formation process of the DLC film. Further, it has been found that even if a large unevenness is generated on the surface of the target, the arc discharge is stabilized by the fact that a larger current is supplied to the graphite target. However, even if the current to be input into the graphite target is set to a large current, if the input power is constant, the arc discharge gradually becomes unstable accompanying the formation process of the DLC film formation, and it becomes difficult to form the adhesion in the form of a thick film. High-hardness DLC film with excellent properties. In particular, when a high current value is applied in a state where the surface of the target is flat in the initial stage of formation of the DLC film, the discharge becomes unstable, and a large amount of droplets are generated, and large unevenness is generated on the surface of the film. There is a problem with the smoothness. The present inventors have found that the DLC film is formed for a certain period of time by setting the current to be input into the graphite target constant, and the current input in the graphite target is increased before the arc current becomes unstable, thereby stabilizing the arc discharge. And the formation of DLC film can continue. Therefore, in the present invention, a step of forming a DLC film by adding an electric current input to the graphite target at the time of film formation is provided. Thereby, the load on the apparatus is small, and the DLC film of high hardness can be stably formed into a thicker film. The current input to the graphite target can be increased stepwise or continuously. In order to form a thicker DLC film, the current input to the graphite target is preferably increased stepwise. Further, it is preferable that the current input to the graphite target is increased by a total of 40 A or more. Further, it is preferably a total of 55 A or more, and more preferably 60 A or more in total. By forming in the above manner, a high hardness DLC film can be stably formed in the form of a thick film. The input current value differs depending on the surface state of the graphite target, and in the initial flat state, the current value is small (30 A to 50 A). Thereafter, it is desirable to increase the current value stepwise. In the second step, the step of reducing the flow rate of the nitrogen gas may be carried out simultaneously with the step of increasing the current supplied to the graphite target, or may be carried out separately. For example, the timing of reducing the flow rate of nitrogen may be the same as the timing of increasing the current input to the graphite target, or may be separated, or the timing of reducing the flow rate of nitrogen may be alternated with the timing of increasing the current input in the graphite target. Settings. Further, it is preferred to finally stop introducing nitrogen gas and increase the power input into the graphite target to form a DLC film. By forming in the above manner, a DLB film having a higher hardness can be made into a thicker film.

If the current input to the graphite target becomes too large, the arc discharge tends to become unstable. In the second step of the present invention, a step of increasing the current input to the graphite target is provided. However, in order to continuously perform stable film formation, the current to be supplied to the graphite target is preferably 150 A or less. Furthermore, it is preferable to set it as 120 A or less. However, if the current input to the graphite target becomes too small, the film formation of the DLC film may not be sufficiently performed. Therefore, the current to be supplied to the graphite target is preferably 20 A or more. More preferably 30 A or more.

Even in the case of a DLC film having a high hardness, if the film thickness is thin, it is difficult to obtain excellent durability. In order to impart excellent durability to the coated tool in a more severe use environment, the film thickness of the DLC film is preferably 1.0 μm or more, and more preferably 1.5 μm or more. More preferably, the film thickness of the DLC film is set to 2.0 μm or more. However, if the film thickness of the DLC film is too thick, the surface roughness of the surface of the film may be deteriorated. Further, if the film thickness of the DLC film having a high hardness becomes too thick, the risk of partial peeling of the DLC film is improved. Therefore, the film thickness of the DLC film is preferably set to 5.0 μm or less. Further, the film thickness of the DLC film is preferably set to 4.0 μm or less.

When the DLC film is formed, the substrate temperature is preferably set to 200 ° C or lower. When the substrate temperature is higher than 200 ° C, the graphitization of the DLC film proceeds, so that the hardness tends to decrease. Further, in forming the DLC film, it is preferable to set the negative bias voltage applied to the substrate to -300 V or more and -50 V or less. When the negative bias applied to the substrate becomes larger than -50 V (the positive side of -50 V), the impact energy of the carbon ions becomes small, and defects such as voids in the DLC film are easily formed. Further, when the negative bias applied to the substrate becomes less than -300 V (on the negative side of -300 V), abnormal discharge is likely to occur during film formation. When the DLC film is formed, the negative bias applied to the substrate is more preferably -200 V or more and -100 V or less.

In the present invention, the substrate (the substrate of the coating tool) for forming the DLC film is not particularly limited, and may be appropriately selected depending on the use, purpose, and the like. For example, superhard alloy, cold work tool steel, high speed tool steel, plastic mold steel, hot work tool steel, etc. can be applied. In the case of the base material, it is preferable that the base material has a large amount of carbides and a high carbon steel or a superhard alloy having a carbon content of 1% or more which is likely to cause peeling of the film. Examples of the high carbon steel include JIS-SKD11 and the like.

Even if it is a DLC film formed by the filtration arc ion plating method, if the film thickness becomes thick, the surface roughness may fall. In this case, it is preferred to perform a polishing treatment after the formation of the DLC film to make it smooth. In the present invention, it is possible to adjust to a more smooth surface state by grinding the surface of the DLC film. Example

<Film Forming Apparatus> The film forming apparatus uses a T-shaped filter arc ion plating apparatus (the volume of the vacuum chamber in the furnace is 0.49 m ³ ). A schematic diagram of the device is shown in Fig. 2. The present invention includes a film forming chamber (6), an arc discharge evaporation source to which a carbon cathode (1) of a graphite target is mounted, and a substrate holder (7) for mounting a substrate. A rotating mechanism (8) is provided below the substrate holder, and the substrate is rotated and revolved via the substrate holder (7). Symbol (2) represents a carbon film-forming bundle, and symbol (3) represents spherical graphite (microdroplet) neutral particles. When an arc discharge is generated on the surface of the graphite target, only carbon having a charge is bent by the magnetic coil (4) to reach the film chamber (6), and the film is coated on the substrate. The droplets without charge are not collected by the magnetic coil and are collected in the pipe (5).

<Substrate> The substrate for evaluating the peeling state of the formed DLC film and evaluating the meltability was a 60 HRC (Rockwell Hardness Number, scale C, C scale) using a size of f20 mm × 5 mm. A steel substrate corresponding to JIS-SKD11 in terms of hardness. Moreover, the base material for measuring the nanoindentation hardness of the formed DLC film, performing the film analysis, and measuring the film thickness of the fracture surface is a tungsten carbide (WC-10 mass% Co) containing a cobalt content of 10% by mass. A superhard alloy substrate (size: 4 mm × 8 mm × 25 mm, average particle size: 0.8 μm, hardness: 91.2 HRA). Further, a scratch test for evaluating the formed DLC film and a substrate for evaluating adhesion by a Rockwell hardness tester were used in a size of 21 mm × 17 mm × 2 mm. Steel substrate for JIS-SKH51. Any of the substrates described above has an arithmetic mean roughness Ra (according to JIS-B-0601-2001) of 0.01 μm or less and a maximum height roughness Rz (according to JIS-B-0601-2001) before forming the DLC film. Grinding is performed in such a manner that the surface roughness is 0.07 μm or less. Then, after the grinding, it is degreased and fixed, and fixed on the substrate holder in the chamber. For each substrate, a DLC film was formed under the following conditions.

<Example 1 of the invention> The inside of the furnace (vacuum chamber) was evacuated until it was 5 × 10 ^-3 Pa, and the substrate was heated to 150 ° C by a heating heater for 90 minutes. Thereafter, the negative bias applied to the substrate was set to -2000 V, and a gas collision treatment was performed for 90 minutes by a mixed gas containing 5% by mass of hydrogen in argon. The flow rate of the mixed gas is set to 50 sccm to 100 sccm. After the gas impact treatment, nitrogen gas was introduced into the furnace, a bias of -150 V was applied to the substrate, and the substrate temperature was set to 100 ° C or lower. Then, the current charged in the graphite target was gradually increased from 40 A to 90 A as described below, and the flow rate of nitrogen gas was gradually reduced from 0 sccm to 0 to form a DLC film. First, the flow rate of nitrogen gas introduced into the furnace was set to 20 sccm, and the current supplied to the graphite target was set to 40 A, and a DLC film was formed in about 30 minutes. Then, the flow rate of nitrogen gas was reduced to 10 sccm, and the current input to the graphite target was increased to 50 A, and a DLC film was formed in about 30 minutes. Then, the flow rate of nitrogen gas was reduced to 5 sccm, and the current input to the graphite target was increased to 60 A, and the DLC film was formed in about 40 minutes. Then, the introduction of nitrogen gas was stopped, the pressure in the furnace was set to 5 × 10 ^-3 Pa or less, and the current supplied to the graphite target was increased to 70 A, and the DLC film was formed in about 40 minutes. Then, the current input to the graphite target was increased to 80 A, and the DLC film was formed in about 40 minutes. Then, the current input to the graphite target was increased to 90 A, and the DLC film was formed in about 60 minutes.

<Example 2 of the invention> The gas impact treatment was carried out in the same manner as in the inventive example 1. After the gas impact treatment, nitrogen gas was introduced into the furnace, a bias of -150 V was applied to the substrate, and the substrate temperature was set to 100 ° C or lower. Then, the current charged in the graphite target was gradually increased from 95 A to 95 A as described below, and the flow rate of nitrogen gas was gradually reduced from 25 sccm to 0 to form a DLC film. First, the flow rate of nitrogen gas introduced into the furnace was set to 25 sccm, and the current supplied to the graphite target was set to 35 A, and a DLC film was formed in about 20 minutes. Then, the flow rate of nitrogen gas was reduced to 20 sccm, and the current input to the graphite target was increased to 40 A, and the DLC film was formed in about 20 minutes. Then, the flow rate of nitrogen gas was reduced to 15 sccm, and the current input to the graphite target was increased to 45 A, and the DLC film was formed in about 20 minutes. Then, the flow rate of nitrogen gas was reduced to 10 sccm, and the current input to the graphite target was increased to 50 A, and the DLC film was formed in about 20 minutes. Then, the flow rate of nitrogen gas was reduced to 7 sccm, and the current input to the graphite target was increased to 55 A, and the DLC film was formed in about 20 minutes. Then, the flow rate of nitrogen gas was reduced to 5 sccm, and the current input to the graphite target was increased to 60 A to form a DLC film in about 20 minutes. Then, the introduction of nitrogen gas was stopped, the pressure in the furnace was set to 5 × 10 ^-3 Pa or less, and the current supplied to the graphite target was increased to 65 A, and the DLC film was formed in about 20 minutes. Then, the current charged in the graphite target was gradually increased to 70 A, 75 A, 80 A, 85 A, and 90 A, and the DLC film was formed at about 20 minutes for each current value.

<Example 3 of the invention> The gas impact treatment was carried out in the same manner as in the inventive example 1. After the gas impact treatment, nitrogen gas was introduced into the furnace, a bias of -150 V was applied to the substrate, and the substrate temperature was set to 100 ° C or lower. Then, the current charged in the graphite target was gradually increased from 95 A to 95 A as described below, and the flow rate of nitrogen gas was gradually reduced from 0 sccm to 0 to form a DLC film. First, the flow rate of nitrogen gas introduced into the furnace was set to 20 sccm, and the current supplied to the graphite target was set to 30 A, and a DLC film was formed in about 20 minutes. Then, the flow rate of nitrogen gas was reduced to 15 sccm, and the current input to the graphite target was increased to 35 A, and the DLC film was formed in about 20 minutes. Then, the flow rate of nitrogen gas was reduced to 10 sccm, and the current input to the graphite target was increased to 40 A, and the DLC film was formed in about 20 minutes. Then, the flow rate of nitrogen gas was reduced to 5 sccm, and the current input to the graphite target was increased to 45 A, and the DLC film was formed in about 20 minutes. Then, the introduction of nitrogen gas was stopped, the pressure in the furnace was set to 5 × 10 ^-3 Pa or less, and the current supplied to the graphite target was increased to 50 A, and the DLC film was formed in about 20 minutes. Then, the current input in the graphite target is gradually increased to 55 A, 60 A, 65 A, 70 A, 75 A, 80 A, 85 A, 90 A, and each time is about 20 minutes at each current value. A DLC film is formed.

<Example 4 of the invention> The gas impact treatment was carried out in the same manner as in the inventive example 1. After the gas impact treatment, C ₂ H ₂ gas and nitrogen gas were introduced into the furnace, and a bias of -150 V was applied to the substrate, and the substrate temperature was set to 100 ° C or lower. Then, the current charged in the graphite target was gradually increased from 95 A to 95 A as described below, and the flow rate of nitrogen gas was gradually reduced from 25 sccm to 0 to form a DLC film. First, the current to be supplied to the graphite target was set to 35 A, and the flow rate of nitrogen gas introduced into the furnace was set to 25 sccm, and the flow rate of C ₂ H ₂ gas was set to 25 sccm to form DLC in about 10 minutes. Membrane. Then, the current input to the graphite target was increased to 40 A, the flow rate of the C ₂ H ₂ gas was reduced to 20 sccm, the flow rate of the nitrogen gas was reduced to 20 sccm, and the DLC film was formed in about 10 minutes. Then, the current input to the graphite target was increased to 45 A, the flow rate of the C ₂ H ₂ gas was reduced to 15 sccm, the flow rate of the nitrogen gas was reduced to 15 sccm, and the DLC film was formed in about 10 minutes. In turn, the graphite target will be charged with the current increased to 50 A, and the flow rate of C ₂ H ₂ gas is reduced to 10 sccm, flow rate of nitrogen was reduced to 10 sccm, about 10 minutes to form a DLC film. Then, the current input to the graphite target was increased to 55 A, the flow rate of the C ₂ H ₂ gas was reduced to 7 sccm, the flow rate of the nitrogen gas was reduced to 7 sccm, and the DLC film was formed in about 10 minutes. Then, the current input to the graphite target was increased to 60 A, the flow rate of the C ₂ H ₂ gas was reduced to 5 sccm, the flow rate of the nitrogen gas was reduced to 5 sccm, and the DLC film was formed in about 10 minutes. Then, the introduction of the C ₂ H ₂ gas and the nitrogen gas was stopped, the pressure in the furnace was set to 5 × 10 ^-3 Pa or less, and the current supplied to the graphite target was increased to 65 A, and the DLC film was formed in about 25 minutes. Then, the current charged in the graphite target was gradually increased to 70 A, 75 A, and 80 A, and the DLC film was formed at about 20 minutes for each current value.

<Example 5 of the invention> The gas impact treatment was carried out in the same manner as in the inventive example 1. After the gas impact treatment, C ₂ H ₂ gas and nitrogen gas were introduced into the furnace, and a bias of -150 V was applied to the substrate, and the substrate temperature was set to 100 ° C or lower. Then, the current charged in the graphite target was gradually increased from 50 A to 80 A as described below, and the flow rate of nitrogen gas was gradually reduced from 15 sccm to 0 to form a DLC film. First, the flow rate of nitrogen gas introduced into the furnace was set to 15 sccm, the flow rate of the C ₂ H ₂ gas was set to 10 sccm, and the current input to the graphite target was set to 50 A, and DLC was formed in about 6 minutes. Membrane. Then, the introduction of the C ₂ H ₂ gas was stopped, the flow rate of the nitrogen gas was set to 15 sccm, and the current supplied to the graphite target was increased to 60 A, and the DLC film was formed in about 45 minutes. Then, the flow rate of nitrogen gas was reduced to 5 sccm, and the current input to the graphite target was increased to 70 A, and the DLC film was formed in about 45 minutes. Then, the introduction of nitrogen gas was stopped, the pressure in the furnace was set to 5 × 10 ^-3 Pa or less, and the current supplied to the graphite target was increased to 80 A, and the DLC film was formed in about 100 minutes.

<Example 6 of the invention> The gas impact treatment was carried out in the same manner as in the inventive example 1. After the gas impact treatment, nitrogen gas was introduced into the furnace, a bias of -150 V was applied to the substrate, and the substrate temperature was set to 100 ° C or lower. Then, the current charged in the graphite target was gradually increased from 25 A to 95 A as described below, and the flow rate of nitrogen gas was gradually reduced from 15 sccm to 0 to form a DLC film. First, the flow rate of the nitrogen gas introduced into the furnace was set to 15 sccm, and the current supplied to the graphite target was set to 25 A, and the DLC film was formed in about 20 minutes. Then, the flow rate of nitrogen gas was reduced to 10 sccm, and the current input to the graphite target was increased to 30 A, and the DLC film was formed in about 20 minutes. Then, the flow rate of nitrogen gas was reduced to 5 sccm, and the current input to the graphite target was increased to 35 A, and the DLC film was formed in about 20 minutes. Then, the introduction of nitrogen gas was stopped, the pressure in the furnace was set to 5 × 10 ^-3 Pa or less, and the current supplied to the graphite target was increased to 40 A, and the DLC film was formed in about 20 minutes. Then, the current input into the graphite target is increased stepwise to 45 A, 50 A, 55 A, 60 A, 65 A, 70 A, 75 A, 80 A, 85 A, 90 A, 95 A, A DLC film was formed at about 20 minutes for each current value.

<Example 7 of the present invention> The gas impact treatment was performed by applying a negative bias voltage to the substrate to -2000 V, and performing a gas impact treatment for 90 minutes by a mixed gas containing 10% by mass of hydrogen gas in argon gas. After the gas impact treatment, nitrogen gas was introduced into the furnace, a bias of -150 V was applied to the substrate, and the substrate temperature was set to 100 ° C or lower. Then, the current charged in the graphite target was gradually increased from 95 A to 95 A as described below, and the flow rate of nitrogen gas was gradually reduced from 25 sccm to 0 to form a DLC film. First, the flow rate of nitrogen gas introduced into the furnace was set to 25 sccm, and the current supplied to the graphite target was set to 35 A, and a DLC film was formed in about 20 minutes. Then, the flow rate of nitrogen gas was reduced to 20 sccm, and the current input to the graphite target was increased to 40 A, and the DLC film was formed in about 20 minutes. Then, the flow rate of nitrogen gas was reduced to 15 sccm, and the current input to the graphite target was increased to 45 A, and the DLC film was formed in about 20 minutes. Then, the flow rate of nitrogen gas was reduced to 10 sccm, and the current input to the graphite target was increased to 50 A, and the DLC film was formed in about 20 minutes. Then, the flow rate of nitrogen gas was reduced to 5 sccm, and the current input to the graphite target was increased to 55 A, and the DLC film was formed in about 20 minutes. Then, the introduction of nitrogen gas was stopped, the pressure in the furnace was set to 5 × 10 ^-3 Pa or less, and the current supplied to the graphite target was increased to 60 A, and the DLC film was formed in about 20 minutes. Then, the current input in the graphite target is gradually increased to 65 A, 70 A, 75 A, 80 A, 85 A, 90 A, 95 A, and the DLC film is formed in each current value for about 20 minutes. .

<Inventive Example 8> The gas impact treatment was performed by applying a negative bias voltage to the substrate to -2000 V, and performing a gas impact treatment for 90 minutes by a mixed gas containing 20% by mass of hydrogen gas in argon gas. After the gas impact treatment, nitrogen gas was introduced into the furnace, a bias of -150 V was applied to the substrate, and the substrate temperature was set to 100 ° C or lower. Then, the current charged in the graphite target was gradually increased from 95 A to 95 A as described below, and the flow rate of nitrogen gas was gradually reduced from 25 sccm to 0 to form a DLC film. First, the flow rate of nitrogen gas introduced into the furnace was set to 25 sccm, and the current supplied to the graphite target was set to 35 A, and a DLC film was formed in about 20 minutes. Then, the flow rate of nitrogen gas was reduced to 20 sccm, and the current input to the graphite target was increased to 40 A, and the DLC film was formed in about 20 minutes. Then, the flow rate of nitrogen gas was reduced to 15 sccm, and the current input to the graphite target was increased to 45 A, and the DLC film was formed in about 20 minutes. Then, the flow rate of nitrogen gas was reduced to 10 sccm, and the current input to the graphite target was increased to 50 A, and the DLC film was formed in about 20 minutes. Then, the flow rate of nitrogen gas was reduced to 5 sccm, and the current input to the graphite target was increased to 55 A, and the DLC film was formed in about 20 minutes. Then, the introduction of nitrogen gas was stopped, the pressure in the furnace was set to 5 × 10 ^-3 Pa or less, and the current supplied to the graphite target was increased to 60 A, and the DLC film was formed in about 20 minutes. Then, the current input in the graphite target is gradually increased to 65 A, 70 A, 75 A, 80 A, 85 A, 90 A, 95 A, and the DLC film is formed in each current value for about 20 minutes. .

<Example 9 of the invention> The gas impact treatment was carried out in the same manner as in the inventive example 1. After the gas impact treatment, nitrogen gas was introduced into the furnace, a bias of -150 V was applied to the substrate, and the substrate temperature was set to 100 ° C or lower. Then, the current charged in the graphite target was gradually increased from 95 A to 95 A as described below, and the flow rate of nitrogen gas was gradually reduced from 40 sccm to 0 to form a DLC film. First, the flow rate of nitrogen gas introduced into the furnace was set to 40 sccm, and the current charged in the graphite target was set to 35 A, and a DLC film was formed in about 20 minutes. Then, the flow rate of nitrogen gas was reduced to 30 sccm, and the current input to the graphite target was increased to 40 A, and the DLC film was formed in about 20 minutes. Then, the flow rate of nitrogen gas was reduced to 20 sccm, and the current input in the graphite target was increased to 45 A, and the DLC film was formed in about 20 minutes. Then, the flow rate of nitrogen gas was reduced to 10 sccm, and the current input to the graphite target was increased to 50 A, and the DLC film was formed in about 20 minutes. Then, the flow rate of nitrogen gas was reduced to 5 sccm, and the current input to the graphite target was increased to 55 A, and the DLC film was formed in about 20 minutes. Then, the introduction of nitrogen gas was stopped, the pressure in the furnace was set to 5 × 10 ^-3 Pa or less, and the current supplied to the graphite target was increased to 60 A, and the DLC film was formed in about 20 minutes. Then, the current input in the graphite target is gradually increased to 65 A, 70 A, 75 A, 80 A, 85 A, 90 A, 95 A, and the DLC film is formed in each current value for about 20 minutes. .

<Example 10 of the invention> The gas impact treatment was carried out in the same manner as in the inventive example 1. After the gas impact treatment, nitrogen gas was introduced into the furnace, a bias of -350 V was applied to the substrate, and the substrate temperature was set to 100 ° C or lower. Then, the current charged in the graphite target was gradually increased from 95 A to 95 A as described below, and the flow rate of nitrogen gas was gradually reduced from 25 sccm to 0 to form a DLC film. First, the flow rate of nitrogen gas introduced into the furnace was set to 25 sccm, and the current supplied to the graphite target was set to 35 A, and a DLC film was formed in about 20 minutes. Then, the negative bias applied to the substrate was set to -300 V, the flow rate of nitrogen gas was reduced to 20 sccm, and the current input to the graphite target was increased to 40 A, and the DLC film was formed in about 20 minutes. Then, the negative bias applied to the substrate was set to -250 V, the flow rate of nitrogen gas was reduced to 15 sccm, and the current input to the graphite target was increased to 45 A, and the DLC film was formed in about 20 minutes. Then, the negative bias applied to the substrate was set to -200 V, the flow rate of nitrogen gas was reduced to 10 sccm, and the current input to the graphite target was increased to 50 A, and the DLC film was formed in about 20 minutes. Then, the negative bias applied to the substrate was set to -150 V, the flow rate of nitrogen gas was reduced to 7 sccm, and the current input to the graphite target was increased to 55 A, and the DLC film was formed in about 20 minutes. Then, the flow rate of nitrogen gas was reduced to 5 sccm, and the current input to the graphite target was increased to 60 A to form a DLC film in about 20 minutes. Then, the introduction of nitrogen gas was stopped, the pressure in the furnace was set to 5 × 10 ^-3 Pa or less, and the current supplied to the graphite target was increased to 65 A, and the DLC film was formed in about 20 minutes. Then, the current charged in the graphite target was gradually increased to 70 A, 75 A, 80 A, 85 A, 90 A, 95 A, and a DLC film was formed at about 20 minutes for each current value.

<Example 11 of the present invention> The gas impingement treatment was carried out by subjecting a negative bias applied to a substrate to -2500 V and performing a gas impact treatment for 90 minutes by a mixed gas containing 5% by mass of hydrogen in argon. After the gas impact treatment, nitrogen gas was introduced into the furnace, a bias of -150 V was applied to the substrate, and the substrate temperature was set to 100 ° C or lower. Then, the current charged in the graphite target was gradually increased from 95 A to 95 A as described below, and the flow rate of nitrogen gas was gradually reduced from 25 sccm to 0 to form a DLC film. First, the flow rate of nitrogen gas introduced into the furnace was set to 25 sccm, and the current supplied to the graphite target was set to 35 A, and a DLC film was formed in about 20 minutes. Then, the flow rate of nitrogen gas was reduced to 20 sccm, and the current input to the graphite target was increased to 40 A, and the DLC film was formed in about 20 minutes. Then, the flow rate of nitrogen gas was reduced to 15 sccm, and the current input to the graphite target was increased to 45 A, and the DLC film was formed in about 20 minutes. Then, the flow rate of nitrogen gas was reduced to 10 sccm, and the current input to the graphite target was increased to 50 A, and the DLC film was formed in about 20 minutes. Then, the flow rate of nitrogen gas was reduced to 7 sccm, and the current input to the graphite target was increased to 55 A, and the DLC film was formed in about 20 minutes. Then, the flow rate of nitrogen gas was reduced to 5 sccm, and the current input to the graphite target was increased to 60 A to form a DLC film in about 20 minutes. Then, the introduction of nitrogen gas was stopped, the pressure in the furnace was set to 5 × 10 ^-3 Pa or less, and the current supplied to the graphite target was increased to 65 A, and the DLC film was formed in about 20 minutes. Then, the current charged in the graphite target was gradually increased to 70 A, 75 A, 80 A, 85 A, 90 A, 95 A, and a DLC film was formed at about 20 minutes for each current value.

<Comparative Example 1> The same procedure as in Example 1 was carried out until the gas impact treatment. After the gas impact treatment, nitrogen gas was introduced into the furnace, a bias of -150 V was applied to the substrate, and the substrate temperature was set to 100 ° C or lower. Then, the current to be supplied to the graphite target was set to 50 A, and the flow rate of nitrogen gas was gradually reduced from 0 sccm to 0 to form a DLC film. First, the flow rate of nitrogen gas introduced into the furnace was set to 10 sccm, and a DLC film was formed in about 10 minutes. Then, the flow rate of nitrogen gas was reduced to 5 sccm, and a DLC film was formed in about 10 minutes. Then, introduction of nitrogen gas was stopped, and the pressure in the furnace was set to 5 × 10 ^-3 Pa or less, and a DLC film was formed in 30 minutes.

<Comparative Example 2> The same procedure as in Example 1 was carried out until the gas impact treatment. After the gas impact treatment, nitrogen gas was not introduced into the furnace, a bias of -150 V was applied to the substrate, and the substrate temperature was set to 100 ° C or lower. Then, the pressure in the furnace was set to 5 × 10 ^-3 Pa or less, and the current charged in the graphite target was set to 50 A, and a DLC film was formed in about 50 minutes.

<Comparative Example 3> The gas impact treatment was performed by applying a negative bias voltage to the substrate to -2000 V and performing a gas impact treatment for 90 minutes by argon gas. After the gas impact treatment, nitrogen gas was introduced into the furnace, a bias of -150 V was applied to the substrate, and the substrate temperature was set to 100 ° C or lower. Then, the current to be supplied to the graphite target was set to 50 A, and the flow rate of nitrogen gas was gradually reduced from 0 sccm to 0 to form a DLC film. First, the flow rate of nitrogen gas introduced into the furnace was set to 10 sccm, and a DLC film was formed in about 10 minutes. Then, the flow rate of nitrogen gas was reduced to 5 sccm, and a DLC film was formed in about 10 minutes. Then, introduction of nitrogen gas was stopped, and the pressure in the furnace was set to 5 × 10 ^-3 Pa or less, and a DLC film was formed in about 30 minutes.

<Comparative Example 4> Under the same conditions as in Comparative Example 3, gas collision treatment was performed only by argon gas, and thereafter, CrN of about 3 μm was formed as an intermediate film. After the intermediate film was formed, nitrogen gas was not introduced, a bias voltage of -150 V was applied to the substrate, and the substrate temperature was set to 100 ° C or lower. Then, the pressure in the furnace was set to 5 × 10 ^-3 Pa or less, and the current charged in the graphite target was set to be constant at 50 A, and the DLC film was formed in about 50 minutes.

<Comparative Example 5> The same procedure as in Example 1 was carried out until the gas impact treatment. After the gas impact treatment, nitrogen gas was introduced into the furnace, a bias of -150 V was applied to the substrate, and the substrate temperature was set to 100 ° C or lower. Then, the current to be supplied to the graphite target was set to 80 A, and the flow rate of nitrogen gas was gradually reduced from 0 sccm to 0 to form a DLC film. First, the flow rate of nitrogen gas introduced into the furnace was set to 10 sccm, and a DLC film was formed in about 25 minutes. Then, the flow rate of nitrogen gas was reduced to 5 sccm, and a DLC film was formed in about 25 minutes. Then, introduction of nitrogen gas was stopped, and the pressure in the furnace was set to 5 × 10 ^-3 Pa or less, and a DLC film was formed in 70 minutes.

<Comparative Example 6> The gas impact treatment was performed by applying a negative bias voltage to the substrate to -1300 V, and performing a gas impact treatment for 90 minutes by a mixed gas containing 5% by mass of hydrogen gas in argon gas. After the gas impact treatment, a bias of -150 V was applied to the substrate, and the substrate temperature was set to 100 ° C or lower. Then, the current to be charged in the graphite target was set to 50 A, and the DLC film was formed in about 50 minutes.

<Comparative Example 7> The gas impact treatment was performed by applying a negative bias voltage to the substrate to -1000 V and performing a gas impact treatment for 90 minutes by a mixed gas containing 5% by mass of hydrogen gas in argon gas. After the gas impact treatment, a bias of -150 V was applied to the substrate, and the substrate temperature was set to 100 ° C or lower. Then, the current to be charged in the graphite target was set to 50 A, and the DLC film was formed in about 50 minutes.

In addition, in any of the above samples, the film formation and cooling were repeated while the temperature of the substrate was 200 ° C or lower, and a DLC film was formed. For each sample in which the DLC film was formed, hardness measurement, surface roughness measurement, adhesion evaluation, and fusion property evaluation were performed. Hereinafter, the measurement conditions will be described.

<Measurement and Evaluation> - Measurement of Nanoindentation Hardness - The hardness of the surface of the film was measured using a nanoindentation apparatus manufactured by ELIONIX Co., Ltd. 10 measurements were made under the measurement conditions of a press load of 9.8 mN, a maximum load holding time of 1 second, and a removal speed of 0.49 mN/sec after the load, according to two places other than the two places where the value is large and the two values are small. Calculated by the average value. It was confirmed that the hardness of the fused silica as a standard sample was 15 GPa, and the hardness of the Chemical Vapor Deposition (CVD) diamond film was 100 GPa.

- Measurement of Surface Roughness - The arithmetic mean roughness Ra and the maximum height roughness Rz were measured in accordance with JIS-B-0601-2001 using a contact surface roughness measuring device SURFCOM480A manufactured by Tokyo Seimitsu Co., Ltd. The measurement conditions were set to an evaluation length of 4.0 mm, a measurement speed of 0.3 mm/s, and a cutoff value of 0.8 mm.

- Evaluation of Adhesion - The surface of the formed DLC film was observed at an magnification of about 800 times using an optical microscope manufactured by Mitutoyo Co., Ltd., and the peeling was evaluated. The evaluation criteria of the surface peeling of the DLC film are as follows. <Evaluation criteria for surface peeling> A: no surface peeling B: slight peeling occurred C: there was coarse peeling

The peeling load (scratch load) was measured using a scratch tester (REVETEST) manufactured by CSM Corporation. The measurement conditions were set to the measurement load: 0 N to 100 N, load speed: 99.25 N/min, scratch speed: 10 mm/min, scratch distance: 10 mm, automatic exposure (AE) sensitivity: 5, pressure Head: Rockwell, diamond, tip radius: 200 μm, hardware setting: Fn contact 0.9 N, Fn speed: 5 N/s, Fn removal speed: 10 N/s, approach speed: 2%/s. The load at the time when the substrate at the bottom of the scratch was completely exposed was evaluated.

A C-scale diamond indenter was used to leave an indentation on the DLC film of each sample by a Rockwell hardness tester (AR-10 manufactured by Mitutoyo). Then, using an optical microscope manufactured by Mitutoyo Co., Ltd., observation was performed at a magnification of about 800 times, and the peeling of the film around the indentation was evaluated. The evaluation criteria of the adhesion by the Rockwell hardness (HRC) indentation test are as follows. <Evaluation Criteria for HRC Indentation Test (HRC Adhesiveness)> A: No peeling, or peeling B having a circle-equivalent diameter of less than 5 μm: slight peeling (peeling of a circle equivalent diameter of 5 μm or more and less than 10 μm) C: There is a large peeling (peeling with a circle equivalent diameter of 10 μm or more)

- Melting test - In order to evaluate the weldability, a ball-on-disc tester (Crib Instruments (Tribometer) manufactured by CSM Instruments) was used. The aluminum A5052 ball (diameter: 6 mm) was pressed against the substrate on which the DLC film was formed with a load of 5 N while rotating the disk-shaped test piece at a speed of 100 mm/sec. The test distance is set to 100 m.

The manufacturing conditions and evaluation results are summarized in Table 1. In the present invention, the present invention is a DLC film having a film thickness of 1.0 μm or more, and has almost no film peeling in the evaluation of the surface peeling and the HRC indentation test, and the scratch load is also 50 N or more. It has excellent adhesion in any evaluation. Further, it was confirmed that no fusion or peeling of the film occurred in the fusion test. Further, in Inventive Example 1 to Inventive Example 11, the arc discharge during film formation was stabilized, and stable film formation was continued. A representative example of a cross-sectional observation photograph of the DLC film coated in the present invention example is shown in Fig. 1 as an example of a cross-sectional observation photograph of the DLC film coated in the fourth embodiment of the present invention. In Fig. 1, it was confirmed that a DLC film which was smooth and free of droplets was coated at about 3.0 μm. As described above, by applying the production method of the present invention, it is possible to coat a DLC film having excellent adhesion, a thick film, high hardness, and few film defects, and it is possible to stably manufacture a coated tool excellent in durability. Comparative Example 1 is a DLC film excellent in adhesion and fusion properties as in the case of the present invention. However, since the current input to the graphite target is constant, the arc discharge becomes unstable, and it is difficult to coat the DLC film which is thicker than this. In Comparative Example 2, since the DLC film was coated without introducing nitrogen gas, the surface peeling tends to occur more easily than the examples of the present invention. Further, it was confirmed that the fusion or peeling was observed in the evaluation of the fusion property. In Comparative Example 3, since the gas impact treatment was performed only by argon gas, the adhesion was lowered as compared with the example of the present invention, and fusion or peeling was confirmed in the evaluation of the meltability. In Comparative Example 4, since the intermediate film of CrN was coated by the gas impact treatment only by argon gas, the adhesion was lowered as compared with the example of the present invention, and fusion or peeling was confirmed in the evaluation of the meltability. Comparative Example 5 is a DLC film excellent in adhesion and weldability as in the case of the present invention. However, since the current input into the graphite target is constant, the arc discharge becomes unstable, and the arc discharge is misfired in the middle, and the film formation is unstable. Further, compared with the invention of the present application, there is a tendency that the scratch load is also lowered. In Comparative Example 6 and Comparative Example 7, since the negative bias applied to the substrate during the gas impact treatment was -1300 V and -1000 V, the removal of residual oxygen on the surface of the substrate was insufficient, which was in accordance with the present invention. The adhesion was lowered, and the fusion or peeling was confirmed in the evaluation of the fusion property.

1‧‧‧Carbon cathode
2‧‧‧Carbon film bundle
3‧‧‧Spherical graphite (microdroplet) neutral particles
4‧‧‧ Magnetic coil
5‧‧‧ Pipes
6‧‧‧filming chamber
7‧‧‧Substrate holder
8‧‧‧Rotating mechanism

Fig. 1 is a cross-sectional observation photograph (×17, 340 times) of a DLC film coated in Example 4 of the present invention by a scanning electron microscope. Fig. 2 is a schematic view showing a T-shaped filter arc ion plating apparatus used in the embodiment.

1‧‧‧Carbon cathode

2‧‧‧Carbon film bundle

3‧‧‧Spherical graphite (microdroplet) neutral particles

4‧‧‧ Magnetic coil

5‧‧‧ Pipes

6‧‧‧filming chamber

7‧‧‧Substrate holder

8‧‧‧Rotating mechanism

Claims (3)

A method for manufacturing a coated tool, which is a method for producing a coated tool for forming a diamond-like carbon film on a surface of a substrate by a filtered arc ion plating method, comprising: a first step of applying the substrate to the substrate The negative bias voltage is set to -2500 V or more and -1500 V or less, a mixed gas containing hydrogen gas is introduced into the furnace, and a gas impact treatment is performed on the surface of the substrate; and a second step, after the gas impact treatment Introducing nitrogen into the furnace, introducing a current into the graphite target to form a diamond-like carbon film on the surface of the substrate, and in the second step, including a step of reducing the flow rate of the nitrogen gas, and increasing a step of applying a current to the graphite target. The method for producing a coated tool according to claim 1, wherein the diamond-like carbon film has a film thickness of 2.0 μm or more. The method of manufacturing a coated tool according to the above aspect, wherein in the step of increasing a current input in the graphite target, a total current increase in the graphite target is increased. 40 A or more.