JP4456374B2 - Hard film, method for producing the same, and target for forming hard film - Google Patents

Description

  The present invention belongs to a technical field related to a hard coating, a method for producing the same, and a target for forming a hard coating, and in particular, improves wear resistance of cutting tools such as chips, drills, and end mills, mechanical parts, or jigs for plastic working. The present invention belongs to a technical field relating to a hard film for manufacturing the same, a method for producing the same, and a target used as an evaporation source in the production of such a hard film.

Conventionally, a hard film such as TiN, TiCN, or TiAlN has been coated for the purpose of improving the wear resistance of a cutting tool based on cemented carbide, cermet, or high-speed tool steel. . In particular, since a composite nitride film of Ti and Al (hereinafter also referred to as TiAlN) exhibits excellent wear resistance, it can be used for high-speed cutting in place of a film made of titanium nitride, carbide, carbonitride, or the like. It is being applied to cutting tools for cutting hard materials such as hardened steel. Furthermore, in recent years, attempts have been made to improve characteristics by adding not only two-element systems such as TiAlN but also third elements. For example, in JP-A-3-120354, JP-A-10-18024, JP-A-10-237628, and JP-A-10-305935, TiAlVN added with V or (TiAlV) (CN) It is disclosed that the film exhibits excellent cutting characteristics in cutting low hardness materials such as S50C. However, it is difficult to say that these coatings have good cutting characteristics with respect to high hardness materials such as quenched SKD materials. Due to demands for higher cutting speeds, these films have higher hardness and wear resistance. Realization of an excellent film is desired. Japanese Patent Application Laid-Open No. 2002-337006 discloses one or more of Group 4, 5 and 6 metal elements, Al and Si, and includes one or more of N, B, C, and O as nonmetal elements. Although the hard coating containing it has been proposed, there is only a description that the Si amount is less than 50% regarding the optimum composition, and cutting performance that surpasses the conventional TiAlN coating can be obtained only by actually combining the above elements. Absent.
Japanese Patent Laid-Open No. 3-120354 Japanese Patent Laid-Open No. 10-18024 Japanese Patent Laid-Open No. 10-237628 Japanese Patent Laid-Open No. 10-305935 JP 2002-337006 A

  The present invention has been made by paying attention to such circumstances, and the purpose thereof is a hard film having higher hardness and superior wear resistance than TiAlN or conventional (TiAlV) (CN), and An object of the present invention is to provide a method for producing such a hard film, and a target for forming a hard film for the production.

The present invention which could achieve the above object relates to a hard film and a method for manufacturing the same, and the hard film forming target, this hard film of claim 1, wherein, a method of manufacturing the hard coating according to claim 2-3, wherein, It is the target for hard-film formation of Claims 4-6 , and it is set as the following structures.

That is, the hard film according to claim 1 is a hard film containing (Ti _a , Al _b , V _c , Si _d ) (C _1-e N _e ),
0.02 ≦ a ≦ 0.5,
0.4 <b ≦ 0.8,
0.05 <c,
0.01 ≦ d ≦ 0.5,
a + b + c + d = 1,
0.5 ≦ e ≦ 1
(A, b, c, and d are atomic ratios of Ti, Al, V, and Si , respectively, and e is an atomic ratio of N). ].

The method for producing a hard film according to claim 2 is the method for producing a hard film according to claim 1 , wherein the metal is evaporated and ionized in a film forming gas atmosphere, and the film forming gas is converted into plasma with the metal. A method for producing a hard coating, characterized in that the film is formed while being promoted [ second invention].

The method for producing a hard coating according to claim 3 uses an arc ion plating method in which evaporation and ionization of a metal constituting the target is performed by arc discharge, and the front is substantially orthogonal to the evaporation surface of the target. 3. The method for producing a hard coating according to claim 2 , wherein a magnetic field line that diverges or travels in parallel is formed, and the film is formed while accelerating the plasma formation of the film forming gas in the vicinity of the object to be processed by the magnetic field line [ third invention].

Hard film-forming target according to claim 4 is a target containing _{(Ti x, Al y, V} z, Si w),
0.02 ≦ x ≦ 0.5,
0.4 <y ≦ 0.8,
0.05 <z,
0.01 ≦ w ≦ 0.5
x + y + z + w = 1
(X, y, z, and w represent atomic ratios of Ti, Al, V, and Si , respectively) and a target for forming a hard film characterized by having a relative density of 95% or more. There is [ fourth invention].

The hard film-forming target according to claim 5 is the hard film-forming target according to claim 4 , wherein Si is present in the form of a compound [ fifth invention].

The hard film forming target according to claim 6 is the hard film forming target according to claim 5, wherein the compound is a Ti-Si compound [ Sixth Invention].

  According to the present invention, it is possible to obtain a hard coating having higher hardness and superior wear resistance than conventional TiAlN coatings and (TiAlV) (CN) coatings. When this hard film is used as a coating film for a cutting tool, a cutting tool capable of cutting at higher speed and higher efficiency can be obtained, and the cutting speed and efficiency can be improved.

Under the circumstances as described above, the present inventors have conducted earnest research aiming at realization of a hard film for a cutting tool that exhibits superior wear resistance. As a result, it was found that if the hardness of the film can be increased as an index, the wear resistance is remarkably improved. And as a result of this, as a result of researches focusing on the addition of Al, V concentration and Si in the (TiAlV) (CN) film, the hardness of the film was obtained by further adding Si to (TiAlV) (CN). As a result of ascertaining that the wear resistance is remarkably improved as a result, and further pursuing further, the present invention has been conceived.

That is, the hard film according to the present invention is a hard film containing (Ti _a , Al _b , V _c , Si _d ) (C _1-e N _e ),
0.02 ≦ a ≦ 0.5,
0.4 <b ≦ 0.8,
0.05 <c,
0.01 ≦ d ≦ 0.5,
a + b + c + d = 1,
0.5 ≦ e ≦ 1
(A, b, c, and d represent the atomic ratio of Ti, Al, V, and Si , respectively, and e represents the atomic ratio of N). The reason for defining the composition of the film will be described in detail below.

  The reason why the upper limit of the atomic ratio of Al is specified is as follows. That is, when the atomic ratio of Al becomes too large, the proportion of Al—N which is an ionic bond increases and the adhesion of the film decreases, so it is necessary to make it 0.8 or less, preferably 0.75. It is as follows. Further, since the increase in hardness is not observed when the atomic ratio of Al is 0.4 or less, the lower limit is set to 0.4.

  Regarding V, if it is less than 0.05, the effect of increasing hardness is small. Therefore, the atomic ratio (c) of V is set to exceed 0.05. That is, 0.05 <c.

Regarding the Si, if the atomic ratio of Si is less than 0.01, the effect of addition is not substantially observed. Si: For than 0.5, together with the hardness of the coating is decreased, the adhesion of the coating is reduced. Therefore, in terms of atomic ratio, the upper limit value of Si was set to 0.5, and the lower limit value of Si was set to 0.01. That is, 0.01 ≦ d ≦ 0.5.

  Regarding the amount of Si, a preferable region varies depending on the composition, but in a film having an Al amount of 0.6 or more, addition of an excessive amount of Si causes a decrease in hardness, so the Si amount is preferably 0.01 to 0.1. When the amount of Al is less than 0.6, the amount of Si is preferably 0.1 to 0.5, and more preferably 0.2 to 0.4.

With respect to Ti, the amount of residual Ti is determined by the amount of Al, V, and Si, but the hardness is reduced when it is less than 0.02, and Al, V, and Si are elements that increase the hardness when it exceeds 0.5. Therefore, the upper limit was set to 0.5.

  Further, the amounts of C and N are as follows. That is, when C is added to the film to precipitate a hard carbide such as TiC, VC, or SiC to increase the hardness of the film, it is desirable that C be present in the same amount as Ti + V + Si. . However, excessive addition of C causes excessive precipitation of unstable aluminum carbides that react with moisture and easily decompose, so the C atomic ratio (1-e) is less than 0.5, The atomic ratio e of N must be 0.5 or more. e is preferably 0.7 or more, more preferably 0.8 or more, and most preferably e = 1.

The hard film according to the present invention can be used by laminating a plurality of different films satisfying the above requirements in addition to a single layer film satisfying the above requirements. Also, in some applications, the specified one or more layers of the present invention on one side or both sides of (TiAlV Si) (CN) film, TiN, TiAlN, TiCrAlN, TiCN , TiAlCN, TiCrAlCN, the TiC etc. It is also possible to use a film as a laminated structure.

  Further, a metal containing at least one metal selected from the group consisting of Group 4A, Group 5A, Group 6A, Al and Si on one side or both sides of the hard coating of the present invention having one layer or two or more layers. One or more layers or alloy layers may be laminated. Examples of the 4A group, 5A group, and 6A group metals include Cr, Ti, Nb, and the like, and Ti—Al or the like is used as the alloy. Can do.

  (I) a metal nitride layer, a metal carbide layer or a metal carbonitride layer satisfying the requirements of the present invention and having a different composition from that of the hard film, and (ii) a hard film, (iii) 4A When a metal layer or alloy layer containing at least one kind of metal selected from the group consisting of Group 5A, Group 6A, Al and Si is used as a hard film having a plurality of layers formed, the film thickness of one layer is However, when the hard coating of the present invention is used, the total film thickness is 0, regardless of whether it is a single layer or a plurality of layers. It is desirable that the thickness be in the range of 5 μm to 20 μm. If the thickness is less than 0.5 μm, the film thickness is too thin and wear resistance is not preferable. On the other hand, if the thickness exceeds 20 μm, the film tends to be broken or peeled off during cutting, which is not preferable. A more preferable film thickness is 1 μm or more and 15 μm or less.

Hard film according to the present invention are those containing _{(Ti a, Al b, V} c, Si d) (C 1-e N e), _{which, (Ti a, Al b,} V c, Si d) (C _1-e N _e ) is included, and it does not mean that it consists only of (Ti _a , Al _b , V _c , Si _d ) (C _1-e N _e ). _{(Ti a, Al b, V} c, Si d) (C 1-e N e) in some cases made from only, not limited thereto, it can contain other components other than the components.

In forming a hard film according to the present invention, in order to sufficiently react a metal element (Al, V, Ti, Si ) and a reactive gas (C, N) to form a high hardness film, the present invention defines. It is very effective to form a film by various methods. That is, it is effective to vaporize and ionize a metal in a film forming gas atmosphere and to form a film while promoting the plasma formation of the film forming gas together with the metal.

  Furthermore, in the arc ion plating method in which the metal constituting the target is evaporated and ionized by arc discharge, a magnetic field line that diverges forward or travels substantially perpendicular to the evaporation surface of the target is formed. It is preferable to form a film while promoting the plasma formation of the film forming gas in the vicinity of the object to be processed.

  In an arc ion plating (AIP) apparatus, it is difficult to produce the coating of the present invention with a cathode evaporation source in which a magnetic field is arranged on the back side of a target as in the prior art, and a magnet is arranged on the side or front of the target. In order to form the hard coating of the present invention, it is very effective to form a magnetic field line that diverges in front of the target evaporating surface and travels in parallel with the target evaporation surface and promotes the formation of plasma of the deposition gas by this magnetic field line. That's it.

  As an example of an apparatus for carrying out the present invention, an AIP apparatus will be briefly described with reference to FIG.

  This AIP (arc ion plating) apparatus ionizes by evaporating a vacuum vessel 1 having an exhaust port 11 for evacuating and a gas supply port 12 for supplying a film forming gas, and a target constituting a cathode by arc discharge. The arc evaporation source 2, the support 3 that supports the object to be processed (cutting tool) W to be coated, and the object W to be processed through the support 3 between the support 3 and the vacuum vessel 1. And a bias power source 4 for applying a bias voltage of.

  The arc evaporation source 2 includes a target 6 constituting a cathode, an arc power source 7 connected between the target 6 and a vacuum vessel 1 constituting an anode, and an evaporation surface S of the target 6 substantially orthogonally. A magnet (permanent magnet) 8 is provided as magnetic field forming means that forms magnetic lines of force that diverge forward or parallel to the front and extend to the vicinity of the workpiece W. As the magnetic flux density in the vicinity of the object to be processed W, the magnetic flux density at the center of the object to be processed is 10 G (Gauss) or more, preferably 30 G or more. Note that being substantially orthogonal to the evaporation surface means that the angle includes 0 ° and 30 ° or less with respect to the normal direction of the evaporation surface.

  FIG. 2 is an enlarged schematic cross-sectional view of an example of the main part of the arc evaporation source used for carrying out the present invention. The magnet 8 as the magnetic field forming means is arranged so as to surround the evaporation surface S of the target 6. ing. The magnetic field forming means is not limited to the magnet, but may be an electromagnet including a coil and a coil power source. Further, as shown in FIG. 3, the magnet may be disposed so as to surround the front (the object to be processed side) of the evaporation surface S of the target 6. In FIG. 1, the chamber is an anode. However, for example, a cylindrical dedicated anode surrounding the front of the target side surface may be provided. In FIG. 3, reference numeral 9 denotes an electromagnet (magnetic field forming means), W denotes a workpiece, and 2A denotes an arc evaporation source.

  4 includes an electromagnet 109 for concentrating arc discharge on the target 106, the electromagnet 109 is located on the back side of the target 106. Therefore, the magnetic field lines are parallel to the target surface in the vicinity of the target evaporation surface, and the magnetic field lines do not extend to the vicinity of the workpiece W.

  The difference in the magnetic field structure between the arc evaporation source of the AIP apparatus used in the present invention and the conventional one is in the difference in how the plasma of the deposition gas spreads.

  As shown in FIG. 3, a part of the electrons e generated by the discharge moves so as to be wound around the magnetic lines of force, and the electrons collide with nitrogen molecules constituting the film forming gas, so that the film forming gas is plasma. Turn into. In the conventional evaporation source 102 in FIG. 4, since the magnetic field lines are limited to the vicinity of the target, the plasma density of the film forming gas generated as described above is highest in the vicinity of the target, and in the vicinity of the workpiece W, the plasma is high. The density is quite low. On the other hand, in the evaporation source used in the present invention as shown in FIG. 2 and FIG. 3, since the lines of magnetic force extend to the workpiece W, the plasma density of the film forming gas in the vicinity of the workpiece W has a conventional evaporation source. It is much higher than.

  And, it is considered that the difference in the magnetic field lines on the surface of the target and the plasma density in the vicinity of the substrate (object to be processed) have a great influence on the crystal structure of the generated film, and thus the obtained characteristics.

  In the present invention, the AIP method has been described as the film forming method. However, the film forming method is not limited to the AIP method as long as the film forming method promotes the plasma formation of the film forming gas together with the metal element. Alternatively, the film can be formed by an ion beam assisted deposition method using nitrogen or nitrogen.

  The hard coating of the present invention is effective to be produced by vapor phase coating methods such as ion plating method and sputtering method by evaporating or ionizing the target as described above and forming a film on the object to be processed. When the characteristics of the target are not preferable, problems such as a stable discharge state cannot be maintained during film formation and the composition of the obtained film is not uniform. Then, in obtaining the hard film of the present invention exhibiting excellent wear resistance, the characteristics of the target used were also examined, and the following findings were obtained.

  First, it was found that by setting the relative density of the target to 95% or more, the discharge state during film formation was stabilized and the hard coating of the present invention was efficiently obtained. That is, when the relative density of the target is less than 95%, a rough portion of an alloy component such as micropores is generated in the target, and when such a target is used for film formation, the evaporation of the alloy component is not performed. It becomes uniform and the composition of the resulting film varies and the film thickness becomes non-uniform. In addition, since the void portion is locally and rapidly consumed during film formation, the depletion rate is increased and the life of the target is shortened. When there are a large number of holes, not only the local wear proceeds rapidly, but also the strength of the target deteriorates and causes cracks. Based on such knowledge, the target for forming a hard film according to the present invention has the same composition (component) as the hard film according to the present invention and has a relative density of 95% or more.

In the vapor phase coating method such as the AIP method, the component composition of the target to be used determines the component composition of the film to be formed. Therefore, the component composition of the target may be the same as the component composition of the target film. preferable. In other words, to obtain a hard coating according to the present invention having excellent wear resistance, as the hard film forming target, a target containing _{(Ti x, Al y, V} z, Si w),
0.02 ≦ x ≦ 0.5,
0.4 <y ≦ 0.8,
0.05 <z,
0.01 ≦ w ≦ 0.5
x + y + z + w = 1
(Where x, y, z, and w are the atomic ratios of Ti, Al, V, and Si , respectively) are preferably used .

  Even if the component composition of the target is satisfied, if the component composition distribution of the target varies, the component composition distribution of the resulting hard coating also becomes non-uniform, and the wear resistance of the coating is partially different. End up. In addition, if there is a variation in the component composition distribution of the target, differences in local electrical conductivity, melting point, and the like occur in the target, which makes the discharge state unstable and does not form a film well. Therefore, the target preferably has a variation in composition distribution within 0.5 at%.

Moreover, although it is Si contained in the target of this invention, it is preferable that it exists in the form of compounds, such as Ti-Si, as a form which exists in a target. The reason is as follows. That is, if Si is alone and surrounded by highly conductive parts such as Ti, V, and Al, the discharge state of the target is microscopically different during sputtering or arc discharge, and the discharge state becomes unstable. May be. Since the Ti—Si compound (for example, Ti ₅ Si ₃ or TiSi ₂ ) has sufficient conductivity, the above-described problems are unlikely to occur. The total Si, the proportion of Ti-Si compound is formed, in terms of its effect, it is preferable that 80% or more.

Such, or the detection of Ti-Si compound is carried out in the X-ray diffraction, although it is possible to detect the Ti-Si binding directly with XPS, as a means of detecting compounds found the following X-ray diffraction preferable.

Incidentally, the present invention is not intended to specify the method of manufacturing the target, for example, raw material Ti powder appropriately adjusting the ratio or particle diameters, V powder and Al powder and a Si Powder, V-type After uniformly mixing with a mixer or the like to obtain a mixed powder, it is subjected to cold isostatic pressing (CIP processing) or hot isostatic pressing (HIP) to obtain the target of the present invention. It is mentioned as an effective method. In addition to these methods, the target of the present invention can also be produced by a hot extrusion method, an ultra-high pressure hot press method, or the like.

In addition, after preparing mixed powder as mentioned above, the method of manufacturing a target by hot press processing (HP) is also mentioned, but in this method, since V used in the present invention is a refractory metal, the relative density Tend to be difficult to obtain a high target. In addition to the method of manufacturing using a mixed powder as described above, a method of obtaining a target by performing a CIP process or a HIP process using a powder that has been alloyed in advance, or by dissolving and solidifying the powder is also included. However, the method of performing CIP treatment or HIP treatment using the alloyed powder has an advantage that a target having a uniform composition can be obtained. However, since the alloy powder is difficult to sinter, a high-density target can be obtained. It tends to be difficult. Further, the latter method of melting and solidifying the alloyed powder has an advantage that a target having a relatively uniform composition can be obtained, but there is a tendency that cracks and shrinkage cavities tend to occur during solidification, and the target of the present invention. Hard to get. The target on which the Ti—Si compound is formed can be obtained by adding Ti ₅ Si ₃ in the form of a compound when the target is manufactured.

  In the method for producing a hard coating according to the present invention, “the magnetic lines of force that diverge forward or proceed in parallel substantially perpendicular to the evaporation surface of the target” means “0-30 ° with respect to the normal direction of the evaporation surface of the target”. It includes magnetic field lines that diverge forward or travel in parallel at an angle of (including 0 ° and 30 °).

  Examples of the present invention and comparative examples will be described below. In addition, this invention is not limited to this Example.

[Example 1, Comparative Example 1]
An alloy target made of Ti, V, Al, and Si is attached to the cathode (that is, target 6) of the AIP apparatus shown in FIG. 1, and a chip made of cemented carbide or cemented carbide is used as a workpiece W on the support base 3. An alloy ball end mill (R 5 mm, 2 blades) was attached, and the chamber (vacuum container) 1 was evacuated. Thereafter, the temperature of the object to be processed is heated to 500 ° C. with a heater in the chamber 1, and after cleaning with Ar ions, nitrogen gas is introduced to make the pressure in the chamber 2.66 Pa, and arc discharge is started. A film having a thickness of about 3 μm was formed on the surface of the object to be processed. Note that a bias voltage of 30 to 200 V was applied to the substrate (object to be processed) so that the substrate (object to be processed) had a negative potential with respect to the ground potential during film formation.

After film formation, the metal component composition and Vickers hardness in the film were examined. The component composition in the film was measured by EPMA. In addition, the amount of impurity elements other than metal elements (Ti, V, Al, Si ) and nitrogen in the coating was 1 at% (atomic%) or less for oxygen and 2 at% or less for carbon.

  Further, in order to evaluate the wear resistance, a wear test was carried out under the following conditions (cutting condition A, cutting condition B) using an end mill having a hard coating formed thereon to measure the wear width in the blade.

<Cutting condition A>
Work material: SKD61 (HRC50)
Cutting speed: 220 m / min Blade feed: 0.06 mm / blade Axial cut: 5 mm
Radial notch: 0.6mm
Cutting length: 50m
Other: Down cut, dry cut, air blow only

<Cutting condition B>
Work material: S55C (HB220)
Cutting speed: 100 m / min (5300 rpm)
Blade feed: 0.05 mm / blade (530 mm / min)
Axial cut: 3 mm
Radial notch: 0.5mm
Other: Down cut, dry cut, air blow only

  The evaluation of the cutting test was performed based on the portion where the wear progressed most in each cutting test, that is, the boundary portion wear in the cutting test of cutting condition A, and the tip end wear in the cutting test of cutting condition B.

  Table 1 shows the results of analysis of the composition of the film, measurement of Vickers hardness, and cutting test. The wear width A is the boundary wear width in the cutting test under the cutting condition A, and the wear width B is the tip wear width in the cutting test under the cutting condition B.

As can be seen from Table 1, the coating is (Ti _a , Al _b , V _c ) (C _{1 -e} N _e ) or (Ti _a , Al _b , V _c , S _d ) (C _{1 -e} N N). _e ) a hard coating comprising an atomic ratio e = 1.

  In Table 1, Nos. 1 to 4, Nos. 8 to 9, Nos. 13 to 14, Nos. 18 to 20, and Nos. 28 are the results for the film according to the comparative example. Nos. 5-7, Nos. 10-12, Nos. 15-17, Nos. 22-27 are the results for the films according to the examples of the present invention.

  The film according to the example of the present invention has high hardness and high hardness as compared with the film according to the comparative example, and the wear width A and / or wear width B is small and excellent in wear resistance. I understand.

[Example 2, Comparative Example 2]
An alloy target made of Ti, V, Al, and Si is attached to the cathode (: target 6) of the AIP apparatus shown in FIG. 1, and a cemented carbide chip or cemented carbide as a workpiece W on the support 3 A ball end mill (R5 mm, 2 blades) was attached, and the inside of the chamber (: vacuum container) 1 was evacuated. Thereafter, the temperature of the object to be processed is heated to 500 ° C. with a heater in the chamber 1, nitrogen gas or a mixed gas of nitrogen and methane is introduced, the pressure in the chamber is set to 2.66 Pa, and arc discharge is started. A film having a thickness of 3 μm was formed on the surface of the object to be processed. Note that a bias voltage of 30 to 200 V was applied to the substrate (object to be processed) so that the substrate (object to be processed) had a negative potential with respect to the ground potential during film formation.

After film formation, the metal component composition and Vickers hardness in the film were examined. The component composition in the film was measured by EPMA. The metal elements (Ti, V, Al, Si ) in the film and the amount of impurity elements other than nitrogen and carbon were at a level of 1 at% or less for oxygen.

  Further, in order to evaluate the wear resistance, an end mill having a hard film formed thereon was used to perform a cutting test under the same conditions (cutting conditions A and cutting conditions B) as in Example 1 to measure the wear width of the middle part of the blade.

  Table 2 shows the results of analysis of the composition of the film, measurement of Vickers hardness, and cutting test.

As can be seen from Table 2, the coating is (Ti _a , Al _b , V _c ) (C _{1 -e} N _e ) or (Ti _a , Al _b , V _c , S _d ) (C _{1 -e} N n). _{It is} a hard film composed of _e ), in which 0.3 ≦ e ≦ 1 and e is changed to various atomic ratios, and the value of (1-e) is also changed accordingly.

  In Table 2, Nos. 1 to 3, No. 8, No. 13, and No. 18 are the results for the film according to the comparative example. The thing of No.4-7, No.9-12, No.14-17 is the result about the film | membrane which concerns on the Example of this invention.

  The film according to the example of the present invention has high hardness and high hardness as compared with the film according to the comparative example, and the wear width A and / or wear width B is small and excellent in wear resistance. I understand. In addition, regarding the influence of C and N among the films according to the examples of the present invention, the larger the atomic ratio of C and the smaller the atomic ratio of N, the higher the hardness and the smaller the wear width A and the wear resistance. Excellent in properties.

[Example 3, Comparative Example 3]
An alloy target made of Ti, V, Al, and Si is attached to the cathode (: target 6) of the AIP apparatus shown in FIG. 1, and a cemented carbide chip or cemented carbide as the workpiece W on the support 1 A ball end mill (R 5 mm, 2 blades) was attached, and the chamber (vacuum container) 1 was evacuated. Thereafter, the temperature of the object to be processed is heated to 500 ° C. with a heater in the chamber 1, nitrogen gas is introduced, the pressure in the chamber 1 is set to 2.66 Pa, and arc discharge is started. A film having a thickness of 3 μm was formed. Note that a bias voltage of 30 to 200 V was applied to the substrate (object to be processed) so that the substrate (object to be processed) had a negative potential with respect to the ground potential during film formation.

After film formation, the metal component composition and Vickers hardness in the film were examined. The component composition in the film was measured by EPMA. The amount of impurity elements other than metal elements (Ti, V, Al, Si ) and nitrogen in the film was at a level of 1 at% or less for oxygen and 2 at% or less for carbon.

  Further, in order to evaluate the wear resistance, an end mill having a hard film formed thereon was used to perform a cutting test under the same conditions (cutting conditions A and cutting conditions B) as in Example 1 to measure the wear width of the middle part of the blade.

  Table 3 shows the results of analysis of the composition of the film, measurement of Vickers hardness, and cutting test.

As can be seen from Table 3, the coating has (Ti _a , Al _b , V _c ) (C _{1 -e} N _e ) or (Ti _a , Al _b , V _c , S _d ) (C _{1 -e} N n). _e ) , the atomic ratio e is all 1, and other atomic ratios are changed to have various atomic ratios.

In Table 3, Nos . 1 to 3 are the results for the film according to the comparative example. Nos . 4 and 10 are the results for the films according to the examples of the present invention.

The film according to the example of the present invention has high hardness and high hardness as compared with the film according to the comparative example, and the wear width A and / or wear width B is small and excellent in wear resistance. I understand .

Example 4
In particular, the density of the target was changed as a parameter. That is, a target composed of (Ti, V, Al, Si ) having various densities is prepared, and film formation is performed by the AIP method or UBMS method. The composition, hardness, and surface roughness of the film after the film formation are adjusted. investigated.

The results are shown in Table 4. Among those shown in Table 4, Nos . 3 to 5 are results on the films obtained when the targets according to the examples of the present invention were used as the targets during film formation. Other than this (namely, Nos . 1 and 2 ) are the results for the film obtained when the target according to the comparative example was used as the target.

As can be seen from Table 4, the film is a hard film made of (Ti _a , Al _b , V _c , Si _d ) (C _1-e N _e ), and Si exists in a non-compound state as a target. It is obtained [No. 1 to 5] when a target is used.

Nos. ₁ to 5 are the results for a film made of (Ti _a , Al _b , V _c , Si _d ) (C _1-e N _e ). The larger the film obtained by using a larger film, the higher the hardness of the film, and the smaller the surface roughness (Ra) value of the film, the smoother the film surface.

  The hard coating according to the present invention has higher hardness and superior wear resistance than conventional TiAlN coatings and (TiAlV) (CN) coatings, so it can be used for coating cutting tools, machine parts, plastic working jigs, etc. It can be used suitably as a film, and their wear resistance can be improved.

It is a schematic diagram which shows the outline | summary of an example of the arc ion plating (AIP) apparatus as an example of an apparatus used for implementation of this invention. It is a schematic diagram which shows an example of the arc type evaporation source principal part with which this invention is implemented. It is a schematic diagram which shows an example of the arc type evaporation source principal part with which this invention is implemented. It is a schematic diagram which shows an example of the arc evaporation source of the conventional arc ion plating (AIP) apparatus.

  1--Vacuum vessel, 2,2A--arc evaporation source, 3--support base, 4--bias power supply, 6--target, 7--arc power supply, 8--magnet (magnetic field forming means), 9 -Electromagnet (magnetic field forming means), 11-- exhaust port, 12-- gas supply port, W-- workpiece, S-- evaporation surface of target.

Claims (6)

A _{(Ti a, Al b, V} c, Si d) (C 1-e N e) hard coating comprising,
0.02 ≦ a ≦ 0.5,
0.4 <b ≦ 0.8,
0.05 <c,
0.01 ≦ d ≦ 0.5,
a + b + c + d = 1,
0.5 ≦ e ≦ 1
(A, b, c, and d are the atomic ratios of Ti, Al, V, and Si , respectively, and e is the atomic ratio of N). 2. The method of manufacturing a hard film according to claim 1, wherein the metal is evaporated and ionized in a film forming gas atmosphere, and the film is formed while promoting the plasma formation of the film forming gas together with the metal. A method for producing a film. Using an arc ion plating method in which evaporation and ionization of the metal constituting the target are performed by arc discharge, a magnetic field line that diverges forward or travels in a direction substantially perpendicular to the evaporation surface of the target is formed. The method for producing a hard coating according to claim 2, wherein the film is formed while accelerating the plasma formation of the film forming gas in the vicinity of the object to be processed by magnetic lines of force. (Ti _x , Al _y , V _z , Si _w ) Including:
0.02 ≦ x ≦ 0.5,
0.4 <y ≦ 0.8,
0.05 <z,
0.01 ≦ w ≦ 0.5
x + y + z + w = 1
(X, y, z, and w are the atomic ratios of Ti, Al, V, and Si, respectively), and the relative density is 95% or more. The hard film-forming target according to claim 4, wherein Si is present in the form of a compound. The hard film-forming target according to claim 5, wherein the compound is a Ti—Si compound.

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