JP2012096353A - Hard film having superior wear resistance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hard film able to be cut with high speed and high efficiency, whose wear resistance is more superior than that of TiAlSiN.SOLUTION: The hard film is composed of (Ti, Al, Cr, Si, B)(CN), wherein 0.5≤a≤0.8, 0.06≤b≤0.3, 0<c≤0.1, 0≤d≤0.1, 0.01≤c+d≤0.1, a+b+c+d<1, 0.5≤e≤1, wherein a, b, c, d and e denote respectively the atomic ratios of Al, Cr, Si, B and N.

Description

  The present invention relates to a hard coating for improving the wear resistance of cutting tools such as chips, drills, and end mills.

  Conventionally, a hard coating such as TiN, TiCN, TiAlN or the like has been applied 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, Al and Si (hereinafter referred to as TiAlSiN) exhibits excellent wear resistance, high-speed cutting can be used in place of the titanium nitride, carbide, carbonitride, etc. It is being applied to cutting tools for cutting high hardness materials such as steel and hardened steel.

  It is disclosed in Patent Document 1 that the TiAlSiN film increases the hardness of the film by adding Al and Si, and the wear resistance is improved, and Al is 0.05 or more in atomic ratio, preferably It has been shown that hardness and oxidation resistance are improved by adding 0.56 or more and Si in an atomic ratio of 0.01 or more, desirably 0.02 or more. However, in recent years, higher speed and higher efficiency are required as usage conditions of cutting tools, and in order to realize such a cutting tool, a hard coating exhibiting further excellent wear resistance is required.

JP, 7-310174, A Claims etc.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a hard coating that is capable of high-speed and high-efficiency cutting and has higher wear resistance than TiAlSiN.

The hard film according to the present _invention, there is provided a hard film composed of _{(Ti 1-a-b-} c-d, Al a, Cr b, Si c, B d) (C 1-e N e),
The above a, b, c, d, e are
0.5 ≦ a ≦ 0.8,
0.06 ≦ b ≦ 0.3,
0 <c ≦ 0.1,
0 ≦ d ≦ 0.1,
0.01 ≦ c + d ≦ 0.1,
a + b + c + d <1,
0.5 ≦ e ≦ 1 is satisfied,
(A, b, c, and d represent the atomic ratio of Al, Cr, Si, and B, respectively, and e represents the atomic ratio of N)
In addition, the gist is that the crystal structure is mainly composed of a rock salt structure type, and the case where the value of e is 1 is a preferable mode.

The diffraction line intensities of the (111) plane, (200) plane and (220) plane of the rock salt structure type measured by X-ray diffraction by the θ-2θ method are I (111), I (200) and I (220), respectively. ), It is preferable that these values satisfy the following formula (1) and / or formula (2) and formula (3).
I (220) ≦ I (111) (1)
I (220) ≦ I (200) (2)
I (200) / I (111) ≧ 0.3 (3)

  Further, the hard film of the present invention has a diffraction angle of diffraction lines on the (111) plane of the rock salt structure type measured by X-ray diffraction by the θ-2θ method using Cu Kα rays. It should be within the range of °.

  The hard film of the present invention includes those in which two or more layers of hard films satisfying the above requirements are formed.

  Further, the hard coating of the present invention has a crystal structure mainly composed of a rock salt structure type on one side or both sides of the one or two or more layers of the hard coating of the present invention, and is different from the hard coating. At least one layer selected from the group consisting of a metal nitride layer, a metal carbide layer and a metal carbonitride layer having a component composition, or at least one selected from the group consisting of 4A group, 5A group, 6A group, Al and Si Also included are those in which one or more metal layers or alloy layers containing seed metals are laminated.

  In the hard film of the present invention, by controlling the component composition of Ti, Al, Cr, Si and B as in the present invention, a hard film having better wear resistance than the conventional hard film could be obtained. .

It is the schematic which showed an example of the arc ion plating (AIP) apparatus used for implementation of this invention. It is the cross-sectional schematic which expanded an example of the arc type evaporation source principal part with which this invention is implemented. It is the cross-sectional schematic which expanded another arc type evaporation source principal part with which it uses for implementation of this invention. It is the cross-sectional schematic which expanded an example of the arc type evaporation source principal part with which implementation of the conventional this invention was carried out.

  Under the circumstances as described above, the present inventors have conducted intensive research aiming to realize a hard coating exhibiting superior wear resistance. As a result, it has been found that if the hardness and oxidation resistance of the film can be increased simultaneously as an index, the wear resistance is remarkably improved. As a result of this research, focusing on the TiAlSiN film, the addition of Cr to TiAlSiN has improved the hardness and oxidation resistance of the film, resulting in a dramatic improvement in wear resistance. Finally, the quantitative effects of TiAlSiN and Cr were investigated. Furthermore, it has been found that adding B is also effective, and the present invention has been conceived.

That is, the hard film of the present invention, Ti, Al, Cr, Si nitride and B or carbonitride _{(Ti 1-a-b-} c-d, Al a, Cr b, Si c, B d) A film made of (C _1-e N _e ), wherein the composition of the nitride or carbonitride is
0.5 ≦ a ≦ 0.8, 0.06 ≦ b ≦ 0.3, 0 <c ≦ 0.1, 0 ≦ d ≦ 0.1, 0.01 ≦ c + d ≦ 0.1, a + b + c + d <1, The reason why 0.5 ≦ e ≦ 1 is satisfied, and the reason why the composition of Ti, Al, Cr, Si, B, C and N in the film is defined in this way will be described in detail below.

  According to Patent Document 1 described above, the basic structure of TiAlSiN is a rock salt structure type, and the composition ratio of Al and Si is set within a range in which the rock salt structure type is maintained. That is, in the above publication, Al is defined to be 0.75 or less in atomic ratio and Si is defined to be 0.1 or less in atomic ratio. When Al and Si exceed the above range, the film changes to a soft hexagonal crystal structure. ing. In addition, Al and Si have an effect of improving oxidation resistance, and it is explained that such an effect is due to formation of thermodynamically stable Al oxide and densification of the Al oxide film by Si. ing. However, as described above, when the ratio of Al and Si exceeds the above range, the crystal structure of the film changes from a rock salt structure to a soft ZnS type hexagonal crystal, so it is not possible to further improve the oxidation resistance in the TiAlSiN system. Is possible.

  On the other hand, a film obtained by adding Al to TiN to improve hardness and oxidation resistance is disclosed in Japanese Patent No. 2644710. When the Al content is 0.6 or more in atomic ratio, a soft hexagonal crystal structure is formed. Precipitation is shown. TiAlN is a rock salt structure type crystal and is considered to be a rock salt structure type composite nitride in which Al is substituted into the Ti site of the rock salt structure type TiN. By the way, since the rock salt structure type AlN is a high-temperature and high-pressure phase, it is expected to be a high-hardness substance. Therefore, it is considered that the hardness of the TiAlN film can be increased by increasing the Al ratio in TiAlN while maintaining the rock salt structure. However, since rock salt structure type AlN is a non-equilibrium phase at room temperature and normal pressure and high temperature and low pressure, it usually produces only soft ZnS type AlN even when vapor phase coating is performed, and it produces rock salt structure type AlN alone. I can't.

However, since TiN is a rock salt structure type and has a lattice constant close to that of a rock salt structure type AlN, AlN is drawn into the structure of TiN, so that a rock salt structure type TiAlN can be generated even at normal temperature and high temperature and low pressure. is there. However, as described above, when TiAlN is expressed as (Al _x , Ti _1-x ) N, if the Al composition ratio x exceeds 0.6 to 0.7, the pulling effect due to TiN becomes weak and soft. ZnS type AlN is deposited.

For TiAlSiN, such detailed structural analysis has not been made. However, the Si—N compound is not a rock salt structure type at normal temperature and pressure, and a hexagonal crystal is formed when the amount of Si is increased. From the precipitation, it is presumed that Si in TiAlSiN has the same behavior as Al in TiAlN described above, that is, is substituted for the Ti lattice position in the TiN lattice.

  The present inventors have focused on this point and found that by adding Cr to TiAlSiN, the oxidation resistance and hardness can be further increased while maintaining the rock salt structure type. This is thought to be due to the following mechanism. That is, since the lattice constant of CrN is closer to rock salt structure type AlN than TiN, the ratio of rock salt structure type AlN can be further increased by partially replacing Ti in TiAlSiN with Cr. If the ratio of the rock salt structure type AlN in the film can be increased by adding Cr in this way, it is considered that the hardness can be made higher than that of the TiAlSiN film.

  On the other hand, since AlN, CrN and Si-N compounds are superior in oxidation resistance to TiN, from the viewpoint of improving oxidation resistance, it is preferable to reduce the proportion of Ti and add Al, Cr and Si. is there. That is, when compared with the conventional TiAlSiN, when the amounts of Al and Si are the same, further oxidation resistance can be improved by replacing a part of Ti with Cr.

Hereinafter, the present invention _{(Ti 1-a-b-} c-d, Al a, Cr b, Si c, B d) (C 1-e N e) Ti constituting the film, Al, Cr, Si, B The reason why the atomic ratios a, b, c, d and e of C, N and N are defined will be described in detail.

  First, for Al, the lower limit of the atomic ratio a was set to 0.5 in order to ensure oxidation resistance and hardness. The reason why the upper limit of the atomic ratio a of Al is set to 0.8 is that when the upper limit is exceeded, soft hexagonal crystals are precipitated and the hardness of the film is lowered.

  By adding Cr, the Al content can be increased while maintaining the rock salt structure type as described above. In order to exert such an effect, the lower limit of the atomic ratio b of Cr is set to 0.06. It was. CrN has a lower hardness than TiN, and excessive addition causes a decrease in hardness, so the upper limit of Cr atomic ratio b was set to 0.3.

  The atomic ratio a of Al is preferably 0.6 or more, and more preferably 0.65 or more. A desirable upper limit of the atomic ratio a of Al is 0.75. The lower limit of the atomic ratio b of Cr is preferably 0.08, and more preferably 0.1. The upper limit of the Cr atomic ratio b is preferably 0.25.

  Si has the effect of improving oxidation resistance as described above, but B also has the same effect, so Si and / or B is added in an atomic ratio (c + d) of 0.01 or more. Preferably it is 0.02 or more. On the other hand, if the ratio of Si and / or B is too large, a soft hexagonal crystal structure is precipitated and wear resistance is impaired, so the upper limit of the atomic ratio of Si and / or B: c, d, or (c + d) Is 0.1. Preferably it is 0.07 or less, More preferably, it is 0.05 or less.

  The amount of Ti is determined by the amounts of Al, Cr, Si, and B. TiN has a higher hardness than CrN, and when Ti is not added at all, the hardness of the film is reduced. The lower limit of the ratio (1-a-b-c-d) is preferably 0.03. More preferably, it is 0.05 or more, More preferably, it is 0.08 or more. Moreover, when the atomic ratio of Al is set to 0.6 or more as a preferable addition amount, if Ti is added excessively, the Cr amount becomes relatively small and the pulling effect becomes small. Is preferably 0.35 or less, more preferably 0.3 or less, and still more preferably 0.25 or less.

By adding C to the film, carbides with high hardness such as TiC, SiC, or B ₄ C can be precipitated to increase the hardness of the film itself. , Si and B are preferably added in the same amount as (1-ab). However, if excessively added, chemically unstable Al ₄ C ₃ , Cr ₇ C _{3, and the} like will be precipitated, and the oxidation resistance is likely to deteriorate. _{Therefore, so-(Ti 1-a-b-} c-d, Al a, Cr b, Si c, B d) (C 1-e Ne) value of e in 0.5 or more. When the hardness is increased by precipitation of the carbide, e is preferably 0.8 or less.

  In addition, it is preferable that the crystal structure of the hard film of the present invention is substantially composed mainly of a rock salt structure type. This is because high strength cannot be secured when a ZnS structure is mixed as described above.

  The crystal structure mainly composed of the rock salt structure type is the (111) plane, (200) plane, (220) plane, (311) plane among the peaks indicating the rock salt structure in X-ray diffraction by the θ-2θ method. The peak intensities are IB (111), IB (200), IB (220), and IB (311), respectively. Among the peaks showing the ZnS type structure, the (100) plane, (102) plane, and (110) plane When the peak intensities are IH (100), IH (102), and IH (110), the crystal structure is such that the value of the following formula (4) is 0.5 or more, preferably 0. .8 or more. This is because when it is less than 0.5, the hardness of the film is lower than the hardness that is preferable in the present invention.

  As for the peak intensity of the ZnS type structure, Cu Kα ray is used in an X-ray diffractometer, the (100) plane is around 2θ = 32 ° to 33 °, the (102) plane is around 2θ = 48 ° to 50 °, The (110) plane is obtained by measuring the intensity of a peak appearing in the vicinity of 2θ = 57 ° to 58 °. The ZnS type crystal is mainly AlN, but Ti, Cr and Si are mixed, so that the measured peak position of ZnS type AlN is slightly different from the peak position of ZnS type AlN on the JCPDS card.

  When the crystal structure of the film of the present invention is measured by X-ray diffraction, the diffraction line intensity in the rock salt structure type crystal structure is I (220) ≦ I (111) and / or I (220) ≦ I (200). It is desirable to satisfy This is because the (111) plane and (200) plane, which are densely packed surfaces of the rock salt structure type, are oriented in parallel to the coating surface, thereby improving the wear resistance.

  Further, the diffraction line intensity ratio of (200) plane to (111) plane; I (200) / I (111) is preferably 0.3 or more. I (200) / I (111) varies depending on conditions such as a bias voltage applied to the substrate during film formation, gas pressure, and film formation temperature. In the present invention, I (200) / I (111) is It has been found that the cutting properties of the film are good when 0.3 or more is satisfied. The details are not clear, but can be considered as follows. In other words, in the rock salt structure type crystal structure, the metal element basically bonds to nitrogen or carbon, and there is almost no bond between metal elements, between nitrogen atoms, or between carbon atoms. Although adjacent atoms are metal elements, nitrogen atoms, or carbon atoms, it is considered that they are not bonded to each other. On the other hand, in the (200) plane, adjacent atoms (nearest neighbor atoms) are a combination of a metal element and nitrogen or a metal element and carbon, and a metal element and a nitrogen atom or carbon atom in the (200) plane are It is considered stable because of the high proportion of bonding. Therefore, if the in-plane highly stable (200) plane is oriented with respect to the surface at a certain ratio with respect to the (111) plane, the hardness increases and the cutting characteristics can be improved. it is conceivable that. The value of I (200) / I (111) is preferably 0.5 or more.

  The diffraction angle of the diffraction line on the (111) plane can vary depending on the composition of the film, the state of residual stress, or the type of the substrate, and θ-2θ using the Kα line of Cu for the hard film of the present invention. As a result of performing X-ray diffraction by the method, the diffraction angle changed within a range of approximately 36.5 ° to 37.5 °, and the diffraction angle tended to decrease as the amount of Ti in the film increased. Thus, as described above, the diffraction angle of the (111) plane becomes lower, that is, the distance between the (111) planes increases as the amount of Ti in the film increases. .24 cm) is considered to be caused by the fact that it is larger than the lattice constant (4.12 cm) of AlN of the rock salt structure type and the lattice constant of CrN (4.14 cm). When the hard coating of the present invention (Ti0.12Al0.70Cr0.15Si0.03) N coating is formed on a cemented carbide substrate, the diffraction angle of the (111) plane varies from 36.6 ° to 37 depending on the deposition conditions. Changed within the range of 1 °.

  The hard coating of the present invention can be used by laminating a plurality of different coatings satisfying the above requirements in addition to a single layer coating satisfying the above requirements. Depending on the application, the crystal structure mainly composed of the rock salt structure type may be provided on one side or both sides of the (Ti, Cr, Al, Si, B) (CN) film defined in the present invention having one layer or two or more layers. In addition, at least one layer selected from the group consisting of a metal nitride layer, a metal carbide layer, and a metal carbonitride layer having a composition different from that of the hard film may be laminated.

  The “crystal structure mainly composed of a salt structure type” as used herein refers to (111) plane, (200) plane, (220) plane, (311) among peaks indicating a rock salt structure in X-ray diffraction by the θ-2θ method. ) Plane peak intensities are IB (111), IB (200), IB (220), and IB (311), respectively, and the (100) plane, (102) plane, (110) out of the peaks showing the ZnS type structure. ) When the peak intensity of the surface is IH (100), IH (102), or IH (110), it means a crystal structure in which the value of the above formula (4) is 0.8 or more. And Examples of the film having a rock salt structure type include films such as TiN, TiAlN, TiCrAlN, TiVAIN, TiCN, TiAlCN, TiCrAlCN, and TiC.

  The hard film of the present invention has at least one selected from the group consisting of 4A group, 5A group, 6A group, Al and Si on one side or both sides of the hard film of the present invention having one or more layers. One or more metal layers or alloy layers containing one kind of metal may be laminated. Examples of the 4A group, 5A group, and 6A group metals include Cr, Ti, Nb, etc. Ti-Al or the like can be used. The formation of such a laminated film is particularly effective when an iron-based base material (HSS, SKD, etc.) having lower adhesion to the hard film than the cemented carbide base material is used as the substrate. On the material, a film of CrN, TiN, TiAlN or the like having a lower hardness than the film specified in the present invention or a metal intermediate layer of Cr, Ti, Ti-Al or the like is formed. By forming a hard film, a hard film with good adhesion to the substrate can be obtained. Further, by forming these films, which are relatively soft as compared with the present invention, as an intermediate layer, residual stress can be reduced, and as a result, improvement in peel resistance (adhesion) is also expected. it can.

  (I) a film satisfying the requirements of the present invention and different from each other, and (ii) a metal nitride layer, a metal carbide layer or a metal carbonitride layer having a rock salt structure type and a composition different from that of the hard film , (Iii) When forming a plurality of metal layers or alloy layers containing at least one metal selected from the group consisting of Group 4A, Group 5A, Group 6A, Al and Si to form the hard coating of the present invention The thickness of one layer should be in the range of 0.005 to 2 μm, but the hard coating of the present invention has a total film thickness of either a single layer or a plurality of layers as described above. , Preferably in the range of 0.5 μm to 20 μm. When the thickness is less than 0.5 μm, the film thickness is too thin and the wear resistance is not preferable. On the other hand, if the film thickness exceeds 20 μm, film defects and peeling occur during cutting. A more preferable film thickness is 1 μm or more and 15 μm or less.

  Further, in order to produce the coating of the present invention whose crystal structure is mainly composed of the rock salt structure type even when the Al composition ratio is high, the film can be formed by the method defined in the present invention. It is very effective. That is, it is a method of performing film discharge while performing arc discharge in a film forming gas atmosphere to evaporate and ionize the metal constituting the target and promote the plasma formation of the film forming gas together with the metal. It is preferable that the film formation gas in the vicinity of the body is formed into a plasma while being promoted by the lines of magnetic force formed so as to diverge forward or proceed substantially in parallel to the evaporation surface of the target.

  In an arc ion plating (AIP) apparatus, a weak magnetic field generation source is disposed on the back side of a target as in the prior art, and a cathode evaporation source having a small vertical component of the magnetic field with respect to the target surface can produce the coating of the present invention. It is difficult, and the magnet is disposed beside or in front of the target to form magnetic lines of force that diverge or advance in the forward direction substantially perpendicular to the target evaporation surface. This is very effective in forming the hard coating of the present invention.

  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 apparatus includes a vacuum vessel 1 having an exhaust port 11 for evacuating and a gas supply port 12 for supplying a film forming gas, and an arc evaporation source 2 for evaporating and ionizing a target constituting a cathode by arc discharge. A support base 3 that supports a target object (for example, a cutting tool) W to be coated, and a negative bias voltage is applied to the target object W through the support base 3 between the support base 3 and the vacuum vessel 1. And a bias power source 4 to be applied.

  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 “substantially perpendicular to the evaporation surface” means that the angle is about 30 ° or less, including 0 ° 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.

  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. The arc evaporation source 102 of the conventional AIP apparatus shown in FIG. 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.

  Such a difference in plasma density of the film forming gas is considered to affect the crystal structure of the generated film.

  Increasing the bias voltage increases the energy of the plasma-forming film forming gas and metal ions, and promotes the formation of a rock salt structure in the film. Therefore, the bias voltage is preferably 50 V or more, and more preferably. Is 70 V or higher, more preferably 100 V or higher. However, if the bias voltage is too high, the film is etched by the plasma-forming film forming gas, and the film forming speed becomes extremely small, which is not practical. Accordingly, the bias voltage is preferably 400 V or less, more preferably 300 V or less, still more preferably 260 V or less, and most preferably 200 V or less. The bias potential is applied so as to be negative with respect to the ground potential. For example, the bias voltage of 100 V indicates that the bias potential is -100 V with respect to the ground potential. The purpose of applying the bias voltage is to give energy to ions of the film forming gas that is incident as described above and ions of metal atoms from the target, and to promote the formation of a rock salt structure of the film, and a preferable range of the bias voltage is formed. Depending on the composition of the film, in the formation of a film with a relatively small amount of Al or a film with a relatively large amount of Cr, the above-mentioned pulling effect works effectively even if the bias voltage is somewhat low, and the rock salt structure is formed. It can be easily achieved. In the formation of a film having an Al content of about 65 atomic% or less or a Cr content exceeding about 25 atomic%, a rock salt structure type single-layer film can be obtained even when the bias voltage is 50 V or less.

  In the present invention, it is preferable that the range of the substrate temperature during film formation is 300 ° C. or higher and 800 ° C. or lower, which is related to the stress of the formed film. The stress of the hard film of the present invention tends to decrease as the substrate temperature increases. When excessive residual stress is acting on the obtained hard film, peeling is likely to occur in a film-formed state, resulting in poor adhesion. Accordingly, the substrate temperature is preferably 300 ° C. or higher, more preferably 400 ° C. or higher, and further preferably 500 ° C. or higher. On the other hand, if the temperature of the substrate (object to be processed) is increased, the residual stress is reduced. However, if the residual stress is too small, the compressive stress is reduced, and the effect of increasing the bending strength of the substrate is impaired. Thermal alteration will also occur. Therefore, the substrate temperature is preferably 800 ° C. or lower. More preferably, it is 700 degrees C or less.

  When the substrate is a cemented carbide base material, the base material temperature is not particularly limited. However, when the base material is a hot tool steel such as HSS (high speed tool steel, SKH51, etc.) or SKD11, SKD61, etc. In this case, it is preferable to maintain the mechanical characteristics of the substrate by setting the substrate temperature during film formation to be equal to or lower than the tempering temperature of the substrate material. The tempering temperature varies depending on the substrate material, for example, about 550 to 570 ° C. for the SKH51, 550 to 680 ° C. for the SKD61, and 500 to 530 ° C. for the high temperature tempering of the SKD11. The tempering temperature or lower is preferable. More preferably, the substrate temperature is about 50 ° C. lower than the respective tempering temperatures.

  Furthermore, in the present invention, it is preferable that the partial pressure or the total pressure of the reaction gas at the time of formation is in a range of 0.5 Pa to 7 Pa. Here, the “partial pressure or total pressure” of the reaction gas is indicated by the fact that the present invention refers to a gas containing an element necessary for the composition of the film, such as nitrogen gas or methane gas, as described above. A rare gas such as argon is called an assist gas, and these are combined to form a film-forming gas. When only the reaction gas is used as the film-forming gas, the total pressure of the reaction gas is controlled. This is because it is effective to control the partial pressure of the reaction gas when both the reaction gas and the assist gas are used. When the partial pressure or total pressure of this reaction gas is less than 0.5 Pa, the generation of macroparticles (melt of the target) generated in the case of arc evaporation increases and the surface roughness increases, which may cause inconveniences depending on the application. It is not preferable. On the other hand, when the partial pressure or total pressure of the reactive gas exceeds 7 Pa, scattering due to collision of the evaporated particles with the reactive gas increases, which is not preferable because the film formation rate is reduced. Preferably it is 1 Pa or more and 5 Pa or less, More preferably, it is 1.5 Pa or more and 4 Pa or less.

  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. When such a target is used for film formation, the alloy component is evaporated. It becomes non-uniform | heterogenous and the component composition of the film | membrane obtained will vary or a film thickness will become non-uniform | heterogenous. 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. The relative density of the target is preferably 96% or more, and more preferably 98% or more.

  Even if the relative density of the target is 95% or more, if the vacancies present in the target are large, the discharge state becomes unstable and a film cannot be formed satisfactorily. It is known that when a hole having a radius of 0.5 mm or more exists in the target, the arc discharge for the evaporation or ionization of the alloy component constituting the target is interrupted and the film formation cannot be performed. As a result of studies by the present inventors, it has been found that when the radius of the hole is 0.3 mm or more, the discharge state becomes unstable even if the discharge is not interrupted. Therefore, in order to maintain a stable discharge state and perform film formation satisfactorily and efficiently, the radius of the vacancy existing in the target should be less than 0.3 mm, preferably 0.2 mm or less.

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 of the present invention excellent in wear resistance, as a _target, consisted of _{(Ti 1-x-y-} z-w, Al x, Cr y, Si z, B w) And
0.5 ≦ x ≦ 0.8,
0.06 ≦ y,
0 ≦ z ≦ 0.1,
0 ≦ w ≦ 0.1,
0.01 ≦ z + w ≦ 0.1,
x + y + z + w <1
It is preferable to use a material satisfying (x, y, z, and w represent atomic ratios of Al, Cr, Si, and B, respectively).

  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 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 of the present invention preferably has a variation in composition distribution within 0.5 at%.

  Furthermore, the present inventors have determined that the content of impurities (oxygen, hydrogen, chlorine, copper, and magnesium) inevitably mixed in the target due to the raw material used for target production or the atmosphere during target production is film formation. The influence on the discharge state at the time was also investigated.

  As a result, if a large amount of oxygen, hydrogen and chlorine is contained in the target, these gases are suddenly generated from the target during film formation, and the discharge state becomes unstable or in the worst case the target itself. It was found that the film was damaged and the film was not formed well. Therefore, oxygen contained in the target should be suppressed to 0.3% by mass or less, hydrogen to 0.05% by mass or less, and chlorine to 0.2% by mass or less. More preferably, oxygen is controlled to 0.2% by mass or less, hydrogen to 0.02% by mass or less, and chlorine to 0.15% by mass or less.

  Further, since copper and magnesium have higher vapor pressures and are more easily vaporized than Ti, Al, Cr, Si and B constituting the target of the present invention, when they are contained in a large amount, they are gasified at the time of target production and are thus formed inside the target. As a result, voids are formed and the discharge state during film formation becomes unstable due to such defects. Therefore, the content of copper contained in the target is preferably suppressed to 0.05% by mass or less, and more preferably 0.02% by mass or less. Moreover, it is preferable to suppress content of magnesium to 0.03 mass% or less, More preferably, it is 0.02 mass% or less.

  Examples of a method for reducing the content of such impurities to the range specified in the present invention include, for example, vacuum melting of the raw material powder and blending and mixing of the raw material powder in a clean atmosphere.

  By the way, although this invention does not specify even about the manufacturing method of a target, the raw material Ti powder, Cr powder, Al powder, Si powder, and B powder which adjusted the quantity ratio, the particle size, etc. appropriately, for example, V A method of applying a cold isostatic pressing process (CIP process) or a hot isostatic pressing process (HIP process) to the mixed powder after uniformly mixing with a mold mixer or the like obtains 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 Cr used in the present invention is a refractory metal, the relative density There is a problem that it is 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, it is difficult to obtain a high-density target. There is a problem. In addition, the latter method of melting and solidifying the alloyed powder has an advantage that a target having a relatively uniform composition can be obtained. However, there is a problem that cracks and shrinkage cavities are easily generated during solidification, and the target of the present invention is used. Difficult to get.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited by the following examples, but may be appropriately modified within a range that can meet the purpose described above and below. It is also possible to implement, and they are all included in the technical scope of the present invention.

[Example 1]
A target alloy made of Ti, Cr, Al, and Si is attached to the cathode of the AIP apparatus shown in FIG. 1, and a cemented carbide chip, a cemented carbide square end mill (diameter 10 mm, 4 blades) or platinum foil (0.2 mm thickness) was attached, and the inside of the chamber was evacuated. Thereafter, the temperature of the object to be processed was heated to 550 ° C. with a heater in the chamber, and the substrate was cleaned with Ar ions for 15 minutes after the degree of vacuum was 3 × 10 ⁻³ Pa or less. Then, nitrogen gas or a mixed gas of nitrogen and methane is introduced to start arc discharge with the pressure in the chamber set to 2.66 Pa and the arc current set to 100 A, and a film with a film thickness of about 3 μm is formed on the surface of the object to be processed. did. Note that a bias voltage of 100 to 200 V was applied to the object to be processed so that the object to be processed had a negative potential with respect to the ground potential during film formation.

  After the film formation, the metal component composition in the film, the crystal structure of the film, the Vickers hardness and the oxidation start temperature were examined. The component composition of Ti, Cr, Al and Si in the film was measured by EPMA (mass absorption coefficient correction). The amount of impurity elements such as O and C excluding metal elements and N in the film is 1 at% or less for oxygen in the quantitative analysis by the EPMA, and 2 at% or less for carbon when methane is not used as a film forming gas. It was a level. The crystal structure of the film was identified by X-ray diffraction. The oxidation start temperature is a temperature at which a weight change occurs when a platinum sample is heated in an artificial dry air with a thermobalance at a rate of temperature increase of 5 ° C./min. did. The value of the formula (4) was obtained by measuring the peak intensity of each crystal plane using Cu Kα rays with an X-ray diffractometer as described above. Table 1 shows the component composition, crystal structure, Vickers hardness (measured at a load of 0.25 N), oxidation start temperature, and the value of the above formula (4) of the obtained film.

  From Table 1, No. The film hardness of TiAlSiN (0.05 ≦ Al ≦ 0.75) shown in Nos. 1 and 2 is 2500 to 2900 and the oxidation start temperature is 700 to 950 ° C. It is possible to increase both the film hardness and the oxidation start temperature simultaneously. Not done. No. 3 to 7 are outside the range defined in the present invention, and either the film hardness or the oxidation start temperature is low. In contrast, No. 1 satisfying the component composition range of the present invention. In 8-18, high Vickers hardness and oxidation start temperature can be achieved simultaneously.

[Example 2]
Of the end mills coated with the hard coating obtained in Example 1, No. Cutting tests were conducted on 2, 4, 6, 9, 11, 13, 16 and 17 to evaluate wear. SKD61 hardened steel (HRC50) was used as the work material. Cutting conditions are as follows. In the wear evaluation, the work width was measured by observing the cutting edge with an optical microscope after cutting the work material by 30 m using each of the end mills. The results are shown in Table 2.

Cutting conditions Cutting speed: 200 m / min
Feeding speed: 0.05mm / blade Cutting depth: 5mm
Pick feed: 1mm
Cutting oil: Air blow only Cutting direction: Down cut

  From Table 2, No. coated with a film satisfying the requirements of the present invention. The end mills 9, 11, 13, 16 and 17 were coated with coatings not satisfying the requirements of the present invention. It can be seen that the wear width is small compared to the 2, 4 and 6 end mills and the wear resistance is excellent.

[Example 3]
Various alloy targets including Ti, Cr, Al, and B are used. Further, a cemented carbide chip and a cemented carbide square end mill (diameter: 10 mm, 4 blades) are used as objects to be processed on the support base as shown in FIG. Attached to the AIP apparatus shown in FIG. 1, the pressure in the chamber is 2.66 Pa, and arc discharge is started with an arc current of 150 A. ) N film was formed. During the film formation, a bias voltage of 150 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. Other film forming conditions are the same as those in the first embodiment. The composition ratio of Ti, Al, Cr, and B in the obtained film was measured by EPMA. Further, the amount of impurity elements such as metal elements and O other than N in the film was at a level of oxygen of 1 at% or less by quantitative analysis with EPMA.

  From Table 3, No. having B amount which is preferable in the present invention. 1-3 are No.1. Since the oxidation start temperature is higher than that of No. 4 and the wear width at the time of the cutting test is small and the wear resistance is excellent, the addition of the B amount so as to satisfy the provisions of the present invention makes it more wear resistant. It can be seen that an excellent hard film can be obtained.

[Example 4]
Using an alloy target having a composition of Ti: 12 at%, Cr: 15 at%, Al: 70 at%, Si: 3 at%, using the AIP apparatus shown in FIG. 1, a cemented carbide square end mill (diameter 10 mm, 4 mm A film having a film thickness of about 3 μm was formed using a single blade), a cemented carbide chip and a platinum foil (thickness: 0.1 mm) as a base material (object to be treated). That is, the (Ti, Cr, Al, Si) N film was formed by changing the bias voltage, the substrate temperature, and the nitrogen gas pressure within the ranges shown in Table 4 or Table 5. The arc current during film formation was 150 A, and other film formation conditions were the same as in Example 1.

  After completion of the film formation, the metal component composition, crystal structure, crystal orientation, diffraction angle of the diffraction line of the (111) plane of the rock salt structure type, Vickers hardness and wear resistance were examined. The crystal structure, crystal orientation, and diffraction angle of the diffraction line of the (111) plane of the rock salt structure type were measured by X-ray diffraction of the θ-2θ method using Kα of Cu. Abrasion resistance was evaluated by a wear width by performing a cutting test in the same manner as in Example 2. The metal component composition of the obtained film was measured by EPMA. The oxidation start temperature of the film formed on the platinum foil was 1100 ° C. or higher.

  From Tables 4 and 5, No. 1 controlled to the substrate voltage, reaction gas pressure, and substrate temperature, which are preferable in the present invention. 1-8, 11, 12, and 15-17 are No.1. Compared with 9, 10, 13, 14, and 18, it has a small wear width and excellent wear resistance. Therefore, by controlling the film forming conditions so as to satisfy the provisions of the present invention, the crystal orientation and diffraction of the film It can be seen that the angle of the line can be set within a preferable range in the present invention, and as a result, a film having excellent wear resistance can be obtained.

[Example 5]
Of the end mills coated with the hard coating obtained in Example 1, No. For 2, 4, 6, 9, 11, and 13, the coating according to the present invention and the coating of Ti _0.5 Al _0.5 N or Ti (C _0.5 N _0.5 ) are alternately (processed object—lower layer—upper layer—lower layer— What was laminated on the upper layer ...) was created. Table 3 shows the types of the laminated films and the total number of laminated films. The total film thickness of the obtained laminated films was about 3 μm. A cutting test was performed using the multilayer coating obtained in this manner, and the wear was evaluated. SKD61 hardened steel (HRC50) was used as the work material. Cutting conditions are as follows. In the wear evaluation, the work width was measured by observing the cutting edge with an optical microscope after cutting the work material by 30 m using each of the end mills. The results are shown in Table 6.

Cutting conditions Cutting speed: 200 m / min
Feeding speed: 0.05mm / blade Cutting depth: 5mm
Pick feed: 1mm
Cutting oil: Air blow only Cutting direction: Down cut

  From Table 6, even if it is a case where a hard film | membrane is made into multiple layers, it is No. No. 9, 11 and 13 are coated with a film that satisfies the requirements of the present invention. It can be seen that the wear width is smaller than the end mills of 2, 4 and 6, and the wear resistance is excellent.

[Example 6]
Using an alloy target having a composition of Ti: 12 at%, Cr: 15 at%, Al: 70 at%, Si: 3 at%, using the AIP apparatus shown in FIG. The nitrogen (or mixture of nitrogen and methane) gas pressure was changed from 0 Pa (metal film) to 2.66 Pa, the bias voltage applied to the substrate was changed within the range of 30 to 150 V, the substrate temperature was changed to 550 ° C., and Table 7 A laminated film of various metal nitrides, carbides, carbonitrides or metal films shown in (1) was formed on a cemented carbide square end mill (diameter 10 mm, 4 blades). Other film forming conditions are the same as those in the first embodiment. The lamination was carried out alternately on the cemented carbide end mill with the film thicknesses shown in Table 7 in the order of the film 1 in Table 7 and then the film 2 in Table 7. The number of layers shown in Table 7 indicates the number of repetitions when [film 1 + film 2] is taken as one unit. The abrasion resistance of the film after film formation was evaluated by performing a cutting test in the same manner as in Example 2. These results are shown in Table 7. The composition ratio of the metal elements in the formed TiAlCrSiN film was Ti: 13 at%, Al: 68 at%, Cr: 16 at%, Si: 3 at%. In addition, the total film thickness of the laminated films was about 3 μm.

  Experiment No. 7 in Table 7 From 1 to 12, even if the hard coating has a plurality of layers, if the coating satisfying the requirements of the present invention is coated, the wear width of the cutting test is 30 μm or less and exhibits excellent wear resistance. I understand.

[Example 7]
The influence of the relative density and impurity content of the target on the discharge state during film formation was investigated.

Each component composition shown in Table 8 is prepared by mixing predetermined amounts of Ti powder, Cr powder, Al powder and Si powder of 100 mesh or less, and performing HIP treatment under conditions of temperature: 900 ° C. and pressure: 8 × 10 ⁷ Pa. A target was prepared. The component composition of the target was measured by ICP-MS. In addition, in order to investigate the discharge characteristics of the obtained target, a target molded to have an outer diameter of 254 mm and a thickness of 5 mm is mounted on a sputtering apparatus, and a coating having a film thickness of about 3 μm is formed by a reactive sputtering method. A film was formed on the manufactured chip. The film formation was performed at an output of 500 W using N2 gas as a reaction gas.

  The component composition of the obtained hard film was measured by XPS, and the wear resistance was evaluated by conducting a cutting test under the following conditions. The discharge state during film formation was performed by visually observing the discharge state on the surface or observing the discharge voltage monitor. These results are shown in Table 8.

Cutting test conditions Work material: SKD61 (HRC50)
End mill: Cemented carbide 4 blades Cutting speed: 200m / min
Cutting depth: 1mm
Feeding speed: 0.05mm / blade Cutting length: 30m
Evaluation criteria ○: Rake face wear depth of less than 20 μm ×: Rake face wear depth of 20 μm or more Discharge state / stable: Instantaneous increase in discharge voltage and local deviation of discharge were observed
None ・ Slightly unstable: Some momentary increase in discharge voltage or local bias in discharge
・ Unstable: Instantaneous rise in discharge voltage and locational bias of discharge are recognized.
Discharged ・ Discharge interruption: Discharge stops

  From Table 8, No. Nos. 1 to 7 satisfy the relative density specified in the present invention, so that the discharge state is good. As a result, a film having the same composition as the target and exhibiting good wear resistance is obtained. I understand that. In contrast, no. 8-10, since the relative density of the target does not satisfy the requirements of the present invention, the discharge state is unstable or cannot be continued. As a result, the component composition of the resulting film is the same as the component composition of the target. The result was that the film was greatly deviated and an unfavorable wear resistance film was obtained.

[Example 8]
A predetermined amount of Ti powder of 100 mesh or less, Cr powder of 100 mesh or less, Al powder of 240 mesh or less, and Si powder of 100 mesh or less are mixed, and the temperature is 500 to 900 ° C. and the pressure is 8 × 10 ⁷ Pa. The target of each component composition shown in Table 9 was prepared by HIP treatment. The obtained target is cut out or a copper backing plate is brazed to produce a target having a fixed collar having an outer diameter of 104 mm and a thickness of 2 mm on the bottom surface. A target was mounted, and a film having a film thickness of about 3 μm was formed on a chip made of cemented carbide, which is an object to be processed. The film formation was performed using N ₂ gas or N ₂ / CH ₄ gas as a reaction gas, the temperature of the object to be processed being 500 ° C., the arc current being 100 A, and the bias potential of the object to be processed being −150 V.

  The component composition of the target was measured by atomic absorption spectrometry. The abrasion resistance of the obtained film was evaluated by the same cutting test method as in Example 2. Moreover, when the component composition of the obtained film | membrane was measured by XPS, the component composition of any film | membrane was in the range of +/- 2at% of the component composition of a target, and was substantially corresponded with the component composition of a target. The presence / absence of defects (holes) in the target and the measurement of the hole size were measured by an ultrasonic flaw detection method. The discharge state during film formation was evaluated by the same method as in Example 7. These results are shown in Table 9.

  From Table 9, No. 1-4, since the relative density of the target and the size of the holes present in the target satisfy the requirements defined in the present invention, the discharge state during the film formation is stable and good wear resistance It turns out that the film | membrane which has is obtained. In contrast, no. In Nos. 5 and 7, the size of the holes present in the target does not satisfy the definition of the present invention. Nos. 9 and 10 indicate that the relative density of the target does not satisfy the provisions of the present invention. Nos. 6 and 8 satisfy neither the relative density of the target defined in the present invention nor the size of the vacancies existing in the target, so that the discharge state becomes unstable or interrupted during the film formation. It became impossible or even when the film was obtained, the abrasion resistance was poor.

[Example 9]
Next, the influence of the content of impurities (oxygen, hydrogen, chlorine, copper and magnesium) in the target on the discharge state during film formation was investigated.

  Targets having respective component compositions shown in Table 10 were produced in the same manner as in Example 7. The relative density of the obtained targets was 99% or more, and there were no vacancies of 0.3 mm or more or continuous defects. Using the obtained target, a film was formed under the same conditions as in Example 7. The content of impurities in the target was measured by atomic absorption spectrometry. The discharge state during film formation was evaluated by the same method as in Example 7. These results are shown in Table 10.

  From Table 10, No. 1,3-9,16 and 17 have good discharge conditions because the contents of all impurities of oxygen, hydrogen, chlorine, copper and magnesium satisfy the requirements of the present invention. I understand. In contrast, no. 2, 10 and 11, the oxygen content, No. 12, hydrogen content, no. In No. 13, the chlorine content, no. In No. 14, the copper content, no. 15, the magnesium content, No. 18 contains oxygen and magnesium contents. In No. 19, the contents of chlorine, copper and magnesium exceed the specified range preferred in the present invention. From these results, the content of impurities (oxygen, hydrogen, chlorine, copper and magnesium) in the target is within the specified range of the present invention in order to obtain a hard coating of the present invention efficiently by improving the discharge state during film formation. It turns out that it is preferable to set it to inside.

DESCRIPTION OF SYMBOLS 1 Vacuum vessel 2, 2A Arc type evaporation source 3 Support stand 4 Bias power supply 6 Target 7 Arc power supply 8 Magnet (magnetic field formation means)
9 Electromagnet (magnetic field forming means)
11 Exhaust port 12 Gas supply port W Processed object S Target evaporation surface

Claims (7)

A _{(Ti 1-a-b-} c-d, Al a, Cr b, Si c, B d) (C 1-e N e) hard film consisting of,
The above a, b, c, d, e are
0.5 ≦ a ≦ 0.8,
0.06 ≦ b ≦ 0.3,
0 <c ≦ 0.1,
0 ≦ d ≦ 0.1,
0.01 ≦ c + d ≦ 0.1,
a + b + c + d <1,
0.5 ≦ e ≦ 1 is satisfied,
(A, b, c, and d represent the atomic ratio of Al, Cr, Si, and B, respectively, and e represents the atomic ratio of N. The same applies hereinafter).
A hard coating with excellent wear resistance, characterized in that the crystal structure is mainly composed of a rock salt structure type.   The hard film according to claim 1, wherein the value of e is 1. The diffraction line intensities of the (111) plane, (200) plane and (220) plane of the rock salt structure type measured by X-ray diffraction by the θ-2θ method are I (111), I (200) and I (220), respectively. The hard film according to claim 1 or 2, wherein these values satisfy the following formula (1) and / or formula (2) and formula (3).
I (220) ≦ I (111) (1)
I (220) ≦ I (200) (2)
I (200) / I (111) ≧ 0.3 (3)   A diffraction angle of a diffraction line of a (111) plane of a rock salt structure type measured by X-ray diffraction using a Cu Kα ray is in a range of 36.5 ° to 37.5 °. Hard coating in any one of 1-3.   A hard coating excellent in wear resistance, characterized in that two or more hard coatings satisfying the requirements according to any one of claims 1 to 4 are formed.   A metal nitride layer and a metal carbide having a crystal structure mainly composed of a rock salt structure type on one side or both sides of the hard coating according to any one of claims 1 to 5, and having a component composition different from that of the hard coating A hard film excellent in wear resistance, wherein at least one layer selected from the group consisting of a layer and a metal carbonitride layer is laminated.   A metal layer 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 according to any one of claims 1 to 6. A hard coating having excellent wear resistance, wherein one or more alloy layers are laminated.

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