JP2017179465A - Hard film, hard film coated member, and method for manufacturing them - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a long life (AlTiVNi)N hard film excellent in oxidation resistance and wear resistance; a (AlTiVNi)N hard film coated member; and a method for manufacturing them.SOLUTION: A hard film 42 has a composition represented by (AlTiVNi)N(a, b, c, d and p are atomic ratios, respectively, 0.45≤a≤0.8, 0.15≤b≤0.5, 0.01≤c≤0.05, 0.001≤d≤0.01, a+b+c+d=1, and 0.2≤p≤0.8), has a Ni-O bond without substantially having an Al-O bond in a bonding state specified by X ray photoelectron spectrometry and has an X diffraction pattern consisting of a rock salt type single structure. The hard film coated member has the hard film 42 on a base 41, and a method for manufacturing them is provided.SELECTED DRAWING: Figure 8

Description

  The present invention relates to (AlTiVNi) N hard coatings excellent in oxidation resistance and wear resistance, members coated with (AlTiVNi) N hard coatings, and methods for producing them.

  It is hoped to form a hard coating with excellent oxidation resistance and wear resistance in order to extend the life of tools that cut workpieces at high feed rates and high speeds, and dies used in harsh molding conditions. Rarely, various proposals have been made.

Patent No. 4528373 (Patent Document 1) is a coated tool wear resistant hard film formed on a substrate, the composition of the hard film is _{(Ti x, Al y, V} z) (C u, N _v , O _w ) (where x, y, z, u, v and w are the atomic ratios of Ti, Al, V, C and O, respectively, x + y + z = 1, u + v + w = 1, 0.2 <x <1 0 <y <0.8, 0.02 ≦ z <0.6, 0 ≦ u <0.7, 0.3 <v ≦ 1, and 0 ≦ w <0.5). Discloses a coated tool formed of two different types of films. However, the abrasion-resistant hard film of Patent Document 1 does not contain Ni and thus does not have a Ni-O bond, so that the oxidation resistance and wear resistance are not necessarily sufficient. This is because the mechanism of the present invention, in which oxygen is diffused from the Ni-O bond to the matrix by the cutting heat during the cutting process and a dense Al protective oxide layer is formed on the surface of the cutting tool, does not work. it is conceivable that.

Patent No. 4346020 (Patent Document 2) has (Ti _a , Al _b , M _c ) (C _1-d N _d ) (where M is Si, Cr or Ni, Ti, Al, A hard coating having a hard coating composition with the atomic ratios a, b, c and d of M and N satisfying 0.02 ≦ a ≦ 0.2, 0.8 ≦ b ≦ 0.95, a + b + c = 1, and 0.5 ≦ d ≦ 1. A coated tool is disclosed. However, since the hard coating of Patent Document 2 does not contain oxygen exceeding the inevitable impurity level and thus has no Ni-O bond, oxygen diffused from the Ni-O bond to the matrix by the cutting heat during the cutting process. Therefore, since the mechanism of the present invention that a dense protective oxide layer of Al is formed on the surface of the cutting tool does not act, oxidation resistance and wear resistance are not necessarily sufficient.

Patent No. 4998304 (Patent Document 3) discloses (Ti _x , Al _y , M _z ) (where M is one or more metals or metalloid elements, and x, y, and z are Ti, The atomic ratio of Al and M satisfying 0.5 ≦ x ≦ 0.8, 0.2 ≦ y ≦ 0.5, z ≦ 0.1, and x + y + z = 1), and formed by a melting method using an electron beam A hard film forming target is disclosed. However, since the target of Patent Document 3 does not contain oxygen exceeding the inevitable impurity level, it has a Ni-O bond substantially without an Al-O bond in the bonding state specified by X-ray photoelectron spectroscopy. However, a hard coating excellent in oxidation resistance and wear resistance cannot be formed by the arc ion plating method.

Patent No. 4528373 Japanese Patent No. 4346020 Patent No.4998304

  Therefore, the first object of the present invention is (AlTiVNi) N hard coating which has better oxidation resistance and wear resistance than conventional (AlTiV) N hard coating and (AlTiNi) N hard coating, and has a long life. Is to provide.

  The second object of the present invention is to form a long-life (AlTiVNi) N hard coating having superior oxidation resistance and wear resistance than the conventional (AlTiV) N hard coating and (AlTiNi) N hard coating. It is to provide a hard-coated member (cutting tool, mold, etc.).

  The third object of the present invention is to provide such a (AlTiVNi) N hard coating and a method for producing the hard coating-coated member.

  The fourth object of the present invention is to provide a target used to produce such (AlTiVNi) N hard coating.

The hard coating of the present invention has (Al _a Ti _b V _c Ni _d ) _(1-p) N _p (where a, b, c, d and p are atomic ratios, 0.45 ≦ a ≦ 0.8, 0.15 ≦ b ≦ 0.5, 0.01 ≦ c ≦ 0.05, 0.001 ≦ d ≦ 0.01, a + b + c + d = 1, and 0.2 ≦ p ≦ 0.8), and a hard film having an X-ray photoelectron spectroscopic analysis method. The identified bonding state is characterized by having an Ni-O bond substantially without an Al-O bond and having an X-ray diffraction pattern consisting of a rock salt type single structure.

  In the hard coating, it is preferable that the bonding state specified by X-ray photoelectron spectroscopy further has a V—O bond.

From the viewpoint of practicality, the hard coating preferably has a droplet made of an oxide containing Ni, Ti and Al as essential components. The droplet is (M _e Ni _1-e ) _(1-q) O _q (where M represents Ti and Al, or Ti, Al and V, and e and q are atomic ratios, respectively, 0.2 ≦ e ≦ 0.8 and 0.05 ≦ q ≦ 0.35).

  Further, the electron diffraction pattern of the hard coating preferably has a rock salt type structure as a main structure and a wurtzite type structure as a sub structure.

  The hard film-coated member of the present invention is characterized in that the hard film is formed on a substrate. Between the substrate and the hard coating, selected from the group consisting of at least one metal element selected from the group consisting of elements of group 4a, 5a and 6a, Al and Si, and B, O, C and N It is preferable to have an intermediate layer that essentially contains at least one element.

The method for producing a hard film-coated member of the present invention in which the hard film is formed on a substrate by an arc ion plating method includes Al _α Ti _β V _γ Ni _δ N _ε O _η (where α, β, γ, δ, ε and η are atomic ratios of Al, Ti, V, Ni, N and O, respectively, 0.45 ≦ α ≦ 0.80, 0.15 ≦ β ≦ 0.48, 0.01 ≦ γ ≦ 0.05, 0.003 ≦ δ ≦ 0.015 And 0.015 ≦ ε ≦ 0.01, 0.015 ≦ η ≦ 0.05, and α + β + γ + δ + ε + η = 1).

  In the method for producing a hard film-coated member of the present invention, when the hard film is formed on the substrate maintained at a temperature of 450 to 550 ° C. in a nitriding gas atmosphere of 2.5 to 5 Pa, the substrate is −150 to It is preferable to apply a DC bias voltage of -40 V or a unipolar pulse bias voltage, and to apply a DC arc current of 150 to 200 A to the target provided in the arc discharge evaporation source.

The target of the present invention used for the production of the hard coating is Al _α Ti _β V _γ Ni _δ N _ε O _η (where α, β, γ, δ, ε and η are Al, Ti, V, Ni, N, respectively) And O, the atomic ratio of 0.45 ≦ α ≦ 0.80, 0.15 ≦ β ≦ 0.48, 0.01 ≦ γ ≦ 0.05, 0.003 ≦ δ ≦ 0.015, 0.001 ≦ ε ≦ 0.01, 0.015 ≦ η ≦ 0.05, and α + β + γ + δ + ε + η = 1 is satisfied. It is made of a sintered alloy having a composition represented by

  The target is obtained by hot pressing a mixed powder composed of Al powder, Ti powder, TiN powder, V powder, VN powder, and Ni powder in a reduced pressure atmosphere at a temperature of 520 to 580 ° C. and a pressure of 1 to 10 Pa. It is preferable to obtain. The reduced pressure atmosphere may be a reduced pressure atmosphere of an oxygen gas atmosphere, but is more preferably an atmospheric reduced pressure atmosphere for practical use.

  Since the hard coating of the present invention contains Ni-O bonds substantially without Al-O bonds in the bonding state specified by X-ray photoelectron spectroscopy, the conventional (AlTiV) N hard coating and (AlTiNi ) Oxidation protective film is easier to form than N hard film, and excellent in oxidation resistance and wear resistance. Further, when V-O bond is included, the wear resistance is further remarkably improved as compared with the conventional (AlTiV) N hard coating and (AlTiNi) N hard coating due to the high temperature lubrication effect by the V-O bond. Therefore, members (cutting tools, dies, etc.) having the hard coating of the present invention have a significantly longer life than before.

  The method of the present invention for producing the hard coating introduces Ni-O bonds and further VO bonds from the (AlTiVNi) NO alloy target obtained by adding a trace amount of oxygen exceeding the inevitable impurity level. The tissue can be controlled stably and efficiently, and its practicality is extremely high.

  The hard film covering member formed by forming the (AlTiVNi) N hard film of the present invention on a cemented carbide substrate, a ceramic substrate such as cBN, sialon, a high-speed steel substrate, or a tool steel substrate has been conventionally used. Compared with the coated member with (AlTiV) N hard coating or (AlTiNi) N hard coating, the oxidation resistance and wear resistance are remarkably improved, so cutting tools such as inserts, end mills, drills, etc. Useful for molds.

It is a front view which shows an example of the arc ion plating apparatus which can be used for formation of the hard film of this invention. 2 is a scanning electron microscope (SEM) photograph (magnification: 25,000 times) showing a cross section of the hard film-coated tool of Example 1. FIG. 2 is a graph showing an X-ray photoelectron spectroscopy spectrum showing the bonding state of Al at the center position of the cross section of the (AlTiVNi) N hard coating film of Example 1. FIG. 2 is a graph showing an X-ray photoelectron spectroscopy spectrum showing a bonding state of Ti at the center position of the cross section of the (AlTiVNi) N hard coating film of Example 1. FIG. 2 is a graph showing an X-ray photoelectron spectroscopy spectrum showing the bonding state of V at the center position of the cross section of the (AlTiVNi) N hard coating film of Example 1. FIG. 2 is a graph showing an X-ray photoelectron spectroscopy spectrum showing a bonding state of Ni at the center position of the cross section of the (AlTiVNi) N hard coating film of Example 1. FIG. 2 is a graph showing an X-ray diffraction pattern of the (AlTiVNi) N hard coating film of Example 1. FIG. 2 is a transmission electron microscope (TEM) photograph (magnification: 16,000 times) showing a cross section of the hard film-coated tool of Example 1. FIG. 2 is a bright field image (magnification: 1,600,000 times) of a TEM showing a cross section of an outer shell portion of a droplet in the (AlTiVNi) N hard coating film of Example 1. FIG. 3 is a graph showing an energy dispersive X-ray analysis spectrum of a matrix portion of the (AlTiVNi) N hard coating film of Example 1. FIG. 3 is a graph showing an energy dispersive X-ray analysis spectrum of an outer shell portion of a droplet in the (AlTiVNi) N hard coating film of Example 1. FIG. 2 is a photograph showing a limited field diffraction image of a matrix part of the (AlTiVNi) N hard coating film of Example 1. FIG. 2 is a photograph showing an FFT pattern of an outer shell portion of a droplet in the (AlTiVNi) N hard film of Example 1. FIG. 2 is a SEM photograph (magnification: 30,000 times) showing the surface of the (AlTiVNi) N hard coating film of Example 1. FIG. It is the schematic which shows an example of the insert base | substrate which comprises the hard film coating | coated member of this invention. It is the schematic which shows an example of the blade-tip-exchange-type rotary tool equipped with the insert. 3 is a SEM photograph (magnification: 30,000 times) showing the surface of the (AlTiVNi) N hard coating film of Comparative Example 1.

[1] Hard film coated member The hard film coated member of the present invention has (Al _a Ti _b V _c Ni _d ) _(1-p) N _p (where a, b, c, d and p are (In terms of atomic ratio, 0.45 ≦ a ≦ 0.8, 0.15 ≦ b ≦ 0.5, 0.01 ≦ c ≦ 0.05, 0.001 ≦ d ≦ 0.01, a + b + c + d = 1, and 0.2 ≦ α ≦ 0.8). A hard film is formed. The X-ray photoelectron spectroscopic spectrum of the hard coating shows that it has Ni-O bonds substantially without Al-O bonds, and the X-ray diffraction pattern shows that it has a rock salt type single structure. The hard coating may further have VO bonds. The hard film can be formed by an arc ion plating (AI) method.

(A) Substrate The substrate needs to be made of a material that has high heat resistance and can be applied to physical vapor deposition. Examples of the material of the substrate include cemented carbide, cermet, high speed steel, tool steel, and ceramics such as cubic boron nitride (cBN). From the viewpoints of strength, hardness, wear resistance, toughness, thermal stability, etc., a WC-based cemented carbide substrate or ceramic is preferred. The WC-based cemented carbide is composed of tungsten carbide (WC) particles and a binder phase of Co or an alloy mainly composed of Co. The content of the binder phase is preferably 1 to 13.5% by mass, and 3 to 13% by mass. More preferred. When the binder phase content is less than 1% by mass, the toughness of the substrate is insufficient, and when the binder phase exceeds 13.5% by mass, the hardness (wear resistance) is insufficient. The (AlTiVNi) N hard coating of the present invention can be formed on any of the unprocessed surface, polished surface, and blade edge processed surface of the sintered WC-based cemented carbide.

(B) Modified layer of WC-based cemented carbide substrate When the substrate is a WC-based cemented carbide, the surface of the substrate is irradiated with ions generated from a TiB target described later to form an fcc structure with an average thickness of 1 to 10 nm. It is preferable to form a modified layer having the same. WC-based cemented carbide has a hexagonal lattice structure with WC as the main component, but the modified layer has the same fcc structure as the (AlTiVNi) N hard coating, and 30% of the crystal lattice fringes at the boundary (interface) between them. Thus, preferably 50% or more, more preferably 70% or more is continuous, and the WC-based cemented carbide substrate and the (AlTiVNi) N hard film are firmly adhered to each other through the modified layer.

  The modified layer obtained by ion bombardment using a TiB target has an fcc structure and is formed into a high-density thin layer, so that it is difficult to be a starting point of fracture. If the average thickness of the modified layer is less than 1 nm, the effect of improving the adhesion of the hard coating to the substrate cannot be obtained sufficiently, and if it exceeds 10 nm, the adhesion is worsened.

(C) (AlTiVNi) N hard coating
(1) Composition
The (AlTiVNi) N hard coating of the present invention formed on the substrate by the AI method is made of a nitride containing Al, Ti, V and Ni as essential elements and containing a trace amount of oxygen exceeding the inevitable impurity level. The composition of the (AlTiVNi) N hard coating is represented by the general formula: (Al _a Ti _b V _c Ni _d ) _(1-p) N _p (atomic ratio) (where a, b, c, d and p are each 0.45 ≦ a ≦ 0.8, 0.15 ≦ b ≦ 0.5, 0.01 ≦ c ≦ 0.05, 0.001 ≦ d ≦ 0.01, a + b + c + d = 1 and 0.2 ≦ p ≦ 0.8. The (AlTiVNi) N hard coating of the present invention has a Ni-O bond specified by an X-ray photoelectron spectroscopy spectrum but substantially no Al-O bond, and also has a rock salt type single in the X-ray diffraction pattern. It has a structure. Here, “substantially free of Al—O bond” means that there is no Al—O bond peak exceeding the inevitable impurity level in the X-ray photoelectron spectroscopy spectrum of the (AlTiVNi) N hard coating. To do. As described later, NiO and Ni ₂ O ₃ are exemplified as the “Ni—O bond”, but other Ni oxides are also included. Similarly, V ₂ O ₃ and V ₂ O ₅ are exemplified as “VO bond” described later, but other V oxides are also included.

  The total ratio of Al, Ti, V and Ni (a + b + c + d) of the (AlTiVNi) N hard coating of the present invention is 1, and the range of the Al ratio a is 0.45 to 0.8. If a is less than 0.45, the amount of Al in the hard coating is too small, so that the oxidation resistance is impaired. On the other hand, if a exceeds 0.8, a soft wurtzite structure is formed in the hard coating, and wear resistance is impaired. The lower limit of a is preferably 0.5, more preferably 0.6. Further, the upper limit of a is preferably 0.75, and more preferably 0.68.

  When the total of Al, Ti, V, and Ni (a + b + c + d) of the hard coating is 1, the range of the Ti ratio b is 0.15 to 0.5. If b is less than 0.15, the amount of Al in the hard coating is too large, so that a soft wurtzite structure is formed in the coating and wear resistance is impaired. On the other hand, if b exceeds 0.5, the amount of Al in the hard coating decreases, so that the oxidation resistance is impaired. The lower limit of b is preferably 0.2, more preferably 0.25. Further, the upper limit of b is preferably 0.4, more preferably 0.3.

  The total of Al, Ti, V and Ni (a + b + c + d) of the hard film is 1, and the range of the ratio c of V is 0.01 to 0.05. If c is less than 0.01, the effect of addition cannot be obtained, and the wear resistance is impaired. On the other hand, since droplets generated when forming a hard film are more likely to be generated than V, V is excessive when c exceeds 0.05, and wear resistance is impaired. The lower limit of c is preferably 0.012, more preferably 0.015. Further, the upper limit of c is preferably 0.03, and more preferably 0.025.

  The range of the ratio d of Ni is 0.001 to 0.01, where 1 is the total of Al, Ti, V and Ni (a + b + c + d) of the hard coating. When d is less than 0.001, a sufficient addition effect cannot be obtained, and the wear resistance is insufficient. On the other hand, when d exceeds 0.01, since Ni is not easily nitrided, pure Ni phase and droplets increase in the film, and wear resistance is impaired. The lower limit of d is preferably 0.002, more preferably 0.003. The upper limit of d is preferably 0.008, more preferably 0.007.

  When the total of the metal component (AlTiVNi) and nitrogen is 1, the ratio p of nitrogen is 0.2 to 0.8, and the ratio (1-p) of metal component (AlTiVNi) is 0.8 to 0.2. When (1-p) is less than 0.2, impurities are easily taken into the grain boundaries of the (AlTiVNi) N polycrystal. Impurities are derived from the internal residue of the film forming apparatus. In such a case, the strength of the (AlTiVNi) N hard coating is reduced, and the (AlTiVNi) N hard coating is easily destroyed by external impact. On the other hand, if (1-p) exceeds 0.8, the ratio of the metal component (AlTiVNi) is excessive, crystal distortion increases, the adhesion with the substrate decreases, and the (AlTiVNi) N hard film peels off. It becomes easy. The lower limit of (1-p) is preferably 0.3, more preferably 0.35. Further, the upper limit of (1-p) is preferably 0.7, more preferably 0.6.

  The Ni—O bond (and V—O bond) of the (AlTiVNi) N hard coating of the present invention can be specified by X-ray photoelectron spectroscopy, but the oxygen content itself cannot be specified by the EPMA analysis described later.

  The (AlTiVNi) N hard coating of the present invention may contain C and / or B. In that case, the total amount of C and B is preferably 30 atomic percent or less of the N content, and more preferably 10 atomic percent or less in order to maintain high wear resistance. In the case of containing C and / or B, the (AlTiVNi) N hard coating can be referred to as nitrocarbide, nitroboride or nitrocarburide.

(2) Mechanism The mechanism by which the (AlTiVNi) N hard coating of the present invention exhibits high oxidation resistance and wear resistance will be described by taking a hard coating coated cutting tool as an example. In general, in an (AlTi) N film-coated cutting tool, a large amount of oxygen is taken in from the surface of the film during cutting, and Al in the vicinity of the film surface is preferentially oxidized to form an Al oxide layer. This Al oxide layer is mainly composed of Al and further has a function of densifying by containing other elements and protecting the cutting tool. An Al oxide layer alone is effective in suppressing cutting tool damage, but it is not always sufficient for the recent demand for higher performance.

  As a result of diligent research to satisfy this requirement, mixed powder of Al powder, Ti powder, V powder and Ni powder, TiN powder and VN powder is taken in by a small amount of oxygen exceeding the inevitable impurity level described below. It was found that the (AlTiVNi) NO sintered body alloy obtained by hot pressing in the atmosphere has an Al—O bond, a Ti—O bond, a Ni—O bond, and a VO bond. When a (AlTiVNi) N hard film is formed by an AI method in a nitriding gas atmosphere using a target composed of a bonded sintered alloy, the following reaction is considered to have occurred. That is, by ionization, Al—O bonds, Ti—O bonds, V—O bonds, and Ni—O bonds in the target disappear, and free Al ions, Ti ions, V ions, and Ni ions are generated. Among these metal ions, Al ions and Ti ions with strong affinity with nitrogen ions form Al-N bonds and Ti-N bonds, and V ions with low affinity with nitrogen ions and strong affinity with oxygen ions. And Ni ions form VO bonds and Ni-O bonds. In the hard coating of the present invention, the composition near the lower limit of the V content may have only a Ni—O bond without a V—O bond as a bond with an oxygen atom.

  Therefore, (a) Droplets mainly composed of oxides of Ni and V are formed on the (AlTiVNi) N hard coating, and (b) Work material (steel or cast iron, etc.) with (AlTiVNi) N hard coating coating tool When cutting is performed, oxygen and Ni diffuse from the droplets into the matrix within the (AlTiVNi) N hard film by cutting heat, and a dense Al oxide layer is formed as a protective film on the surface of the cutting tool. Furthermore, V oxide plays a role of high temperature lubrication and contributes to improvement of wear resistance. By such a mechanism, it is considered that the tool coated with the (AlTiVNi) N hard coating of the present invention exhibits superior oxidation resistance and wear resistance as compared with conventional cutting tools.

(3) Film thickness Although not particularly limited, the arithmetic average thickness of the (AlTiVNi) N hard coating of the present invention is preferably 0.5 to 15 μm, more preferably 1 to 10 μm. With a film thickness in this range, the (AlTiVNi) N hard coating is prevented from peeling from the substrate. If the average thickness is less than 0.5 μm, the effect of the (AlTiVNi) N hard coating cannot be obtained sufficiently.If the average thickness exceeds 15 μm, the residual stress becomes excessive, and the (AlTiVNi) N hard coating peels off from the substrate. It becomes easy.

(4) Crystal structure
In the X-ray diffraction pattern, the (AlTiVNi) N hard coating of the present invention has a rock salt type single structure. Further, in the limited-field diffraction pattern by TEM, the (AlTiVNi) N hard coating of the present invention may have a rock salt type as a main structure and other structures (such as a wurtzite structure) as a substructure. In a practical (AlTiVNi) N hard coating, it is preferable to use a rock salt structure as a main structure and a wurtzite structure as a substructure.

(D) Intermediate layer Between the substrate and the (AlTiVNi) N hard coating, by physical vapor deposition, at least one element selected from the group consisting of elements 4a, 5a and 6a, Al and Si, and B, An intermediate layer that essentially includes at least one nonmetallic element selected from the group consisting of O, C, and N may be formed. The intermediate layer is TiN, (TiAl) N, (TiAl) NC, (TiAl) NCO, (TiAlCr) N, (TiAlCr) NC, (TiAlCr) NCO, (TiAlNb) N, (TiAlNb) NC, (TiAlNb) NCO , (TiAlW) N, (TiAlW ) NC, (TiSi) N, (TiB) N, TiCN, Al 2 O 3, Cr 2 O 3, (AlCr) 2 O 3, (AlCr) N, (AlCr) NC, And at least one selected from the group consisting of (AlCr) NCO. The intermediate layer may be a single layer or a stacked layer.

[2] Deposition equipment
An AI apparatus can be used to form the (AlTiVNi) N hard coating, and an AI apparatus or other physical vapor deposition apparatus (such as a sputtering apparatus) can be used to form the modified layer and the intermediate layer. For example, as shown in FIG. 1, the AI apparatus includes arc discharge evaporation sources 13 and 27 attached to the decompression vessel 5 via an insulator 14, and targets 10 attached to the arc discharge evaporation sources 13 and 27, respectively. , 18, arc discharge power sources 11, 12 connected to the respective arc discharge evaporation sources 13, 27, a rotatable column 6 penetrating to the inside of the decompression vessel 5 through the bearing portion 4, and the base body 7 are held For this purpose, a holder 8 supported by the support column 6, a drive unit 1 that rotates the support column 6, and a bias power source 3 that applies a bias voltage to the substrate 7 are provided. The decompression vessel 5 is provided with a gas introduction part 2 and an exhaust port 17. The arc ignition mechanisms 16 and 16 are attached to the decompression vessel 5 via arc ignition mechanism bearing portions 15 and 15. In order to ionize a gas (argon gas, nitrogen gas, etc.) introduced into the decompression vessel 5, a filament type electrode 20 is attached to the decompression vessel 5 via insulators 19 and 19. Between the target 10 and the base body 7, a shielding plate 23 is provided in the decompression vessel 5 via a shielding plate bearing portion 21. The shielding plate 23 is moved, for example, vertically or horizontally by the shielding plate driving unit 22, and after the shielding plate 22 is not present between the target 10 and the base body 7, the (AlTiVNi) N hard coating of the present invention is used. Formation takes place.

(A) (AlTiVNi) N Hard coating target
(1) Compounding composition (AlTiVNi) N hard film forming target of the present invention is obtained by mixing each raw material powder composed of Al powder, Ti powder, TiN powder, V powder, VN powder, and Ni powder with the following compounding composition. A formed body made of the mixed powder is sintered. The composition of the raw material powder is Al _h Ti _i (TiN) _j V _k (VN) _l Ni _m (where h, i, j, k, l and m are atomic ratios, 0.47 ≦ h ≦ 0.82, 0.1 ≦ i ≦ 0.45, 0.02 ≦ j ≦ 0.1, 0.007 ≦ k ≦ 0.047, 0.001 ≦ l ≦ 0.01, 0.0045 ≦ m ≦ 0.013, and h + i + j + k + l + m = 1. If h, i, j, k, l and m are not within the above ranges, the (AlTiVNi) N hard film forming target and the (AlTiVNi) N hard film of the present invention having the following sintered alloy composition are obtained. I can't. h, i, j, k, l and m are atomic ratios of 0.60 ≦ h ≦ 0.81, 0.10 ≦ i ≦ 0.30, 0.02 ≦ j ≦ 0.10, 0.008 ≦ k ≦ 0.035, 0.004 ≦ l ≦ 0.01, 0.005 ≦ m More preferably, ≦ 0.011 and h + i + j + k + l + m = 1 are satisfied.

(2) Sintered body composition The composition of the target of the present invention made of a sintered body alloy is Al _α Ti _β V _γ Ni _δ N _ε O _η (except α, β, γ, δ, ε, except for inevitable impurities). And η are atomic ratios of Al, Ti, V, Ni, N, and O, respectively, 0.45 ≦ α ≦ 0.80, 0.15 ≦ β ≦ 0.48, 0.01 ≦ γ ≦ 0.05, 0.003 ≦ δ ≦ 0.015, 0.001 ≦ ε ≦ 0.01, 0.015 ≦ η ≦ 0.05, and α + β + γ + δ + ε + η = 1). If (alpha), (beta), (gamma), (delta), (epsilon), and (eta) are each in the said range, the (AlTiVNi) N film | membrane of this invention will not be obtained. As described above, in addition to metal Al, metal Ti, metal V, and metal Ni, (a) the above amounts of Ti nitride and V nitride are added, and (b) the sintered alloy. By adding a small amount of the above amount of oxygen to the target, a Ni—O bond and further a VO bond can be independently introduced into the (AlTiVNi) N film. α, β, γ, δ, ε, and η are atomic ratios of 0.50 ≦ α ≦ 0.80, 0.20 ≦ β ≦ 0.40, 0.015 ≦ γ ≦ 0.045, 0.004 ≦ δ ≦ 0.015, 0.001 ≦ ε ≦ 0.01, 0.015 ≦ η More preferably, ≦ 0.050 and α + β + γ + δ + ε + η = 1 are satisfied.

  The (AlTiVNi) N hard film forming target can be produced, for example, by the powder metallurgy method as follows. First, Al powder, Ti powder, TiN powder, V powder, VN powder, and Ni powder are ball-milled for several hours (for example, 6 hours) in an air atmosphere. The average particle size of each powder is preferably 0.01 to 500 μm, more preferably 0.1 to 100 μm. The average particle size of each powder is determined by SEM observation. In order to prevent compositional deviation and contamination of impurities, it is preferable to use alumina balls having a purity of 99.999% or more for the grinding media of the ball mill.

  The obtained mixed powder is put into a graphite mold of a hot press sintering apparatus and sintered. It is necessary that oxygen be present in the mold during sintering to generate an oxide of Ni (preferably also an oxide of V). Therefore, it is preferable to press and sinter after reducing the air in the sintering apparatus to a vacuum degree of 1 to 10 Pa (for example, 5 Pa). The press load is preferably set to 100 to 200 MPa (for example, 160 MPa). In order to avoid dissolution of Al during sintering, the sintering is preferably performed at a temperature of 520 to 580 ° C. (eg 550 ° C.) for several hours (eg 2 hours). The target material obtained by sintering is processed into a shape suitable for an AI device to obtain a target for forming an (AlTiVNi) N hard coating.

  The target includes V and Ni oxides. Each oxide of V and Ni becomes V ion, Ni ion and O ion by the arc spot at the time of film formation, and the droplet composed of V oxide and Ni oxide reacts with each other in the (AlTiVNi) N hard coating. It is formed. V oxide plays a role of high-temperature lubrication, and Ni oxide plays a role of densifying the Al oxide layer that protects the contact portion. On the other hand, since the target has a high Al content and a V-added composition, droplets are easily generated by the AI method. It has been found that droplets can be reduced by adding predetermined amounts of TiN and VN.

(B) TiB target for modified layer formation TiB target for modified layer formation is Ti _f B _1-f (except for inevitable impurities), where f is the atomic ratio of Ti, and 0.5 ≦ f ≦ 0.9. It has a composition represented by: If the atomic ratio f of Ti is less than 0.5, a modified layer having a cubic structure cannot be obtained, and if f exceeds 0.9, a decarburized phase is formed, and a modified layer having a cubic structure cannot be obtained. A preferable range of the atomic ratio f of Ti is 0.7 to 0.9.

The TiB target for forming the modified layer is also preferably produced by a hot press method. Since oxygen manufacturing process is the minimizing being mixed, the TiB powder was charged, for example, in a hot press sintering apparatus WC group in hard metal ^{mold, 1 × 10 -3 Pa~10 × 10} -3 Pa Sintering is performed for several hours (for example, 2 hours) in an atmosphere reduced to (for example, 7 × 10 ⁻³ Pa). The obtained sintered body is processed into a shape suitable for the AI device to obtain a modified layer forming TiB target.

(C) Arc discharge evaporation source and arc discharge power source As shown in FIG. 1, arc discharge evaporation sources 13 and 27 are respectively formed of a TiB target 10 for forming a modified layer of cathode material and an (AlTiVNi) N hard coating. The target 18 is provided, and a direct current arc current is supplied to the target 10 from the arc discharge power supplies 11 and 12 under the conditions described later, and a pulsed arc current is supplied to the target 18. Although not shown, the arc discharge evaporation sources 13 and 27 are provided with a magnetic field generating means (a structure having an electromagnet and / or a permanent magnet and a yoke), in the vicinity of the base 7 on which the (AlTiVNi) N hard film is formed. It is preferable to form a magnetic field distribution with a gap magnetic flux density of several tens of G (for example, 10 to 50 G).

  Since the target for forming (AlTi) N hard coating contains Al and V, where droplets are easily generated, the arc spot stays in the Al and V portions during the process of forming (AlTi) N hard coating in the conventional AI method. . When the arc spot stays, a large melting portion is generated in the staying portion, and droplets in the melting portion adhere to the surface of the substrate. These droplets are called droplets and roughen the surface of the (AlTi) N hard coating. The droplets cause fragmentation of the growth of the (AlTiVNi) N polycrystalline grains and also serve as a starting point for film destruction. For this reason, it is preferable that Ni and V oxides are formed in the outer shell of the droplet and that the droplet is not excessive. In the present invention, excessive generation of droplets is suppressed by passing a direct current arc current of 150 to 200 A to a target (evaporation source) containing TiN and VN.

(D) Bias power source As shown in FIG. 1, a DC voltage or a pulse bias voltage is applied to the substrate 7 from the bias power source 3.

[3] Film formation conditions
(Al _a Ti _b V _c Ni _d ) _(1-p) N _p (where a, b, c and p are atomic ratios, 0.45 ≦ a ≦ 0.8, 0.15 ≦ b ≦ 0.5, 0.01 ≦ c ≦ 0.05, respectively) , 0.001 ≦ d ≦ 0.01, a + b + c + d = 1, and 0.2 ≦ p ≦ 0.8), and include a Ni—O bond (preferably a VO bond) in the bonding state specified by X-ray photoelectron spectroscopy. The (AlTiVNi) N hard film of the present invention can be formed by an AI method using the above-mentioned (AlTiVNi) N hard film forming target. The film forming conditions of the (AlTiVNi) N hard coating of the present invention will be described in detail below for each process.

(A) Substrate cleaning process After the substrate 7 is set on the holder 8 of the AI apparatus shown in FIG. 1, the inside of the vacuum vessel 5 is held at 1 to 5 × 10 ⁻² Pa (for example, 1.5 × 10 ⁻² Pa). Meanwhile, the substrate 7 is heated to a temperature of 250 to 650 ° C. by a heater (not shown). Although shown in FIG. 1 as a cylinder, the substrate 7 can take various shapes such as a solid type end mill or insert. Thereafter, argon gas is introduced into the decompression vessel 5 to obtain an argon gas atmosphere of 0.5 to 10 Pa (for example, 2 Pa). In this state, a DC bias voltage or a pulse bias voltage of −250 to −150 V is applied to the substrate 7 from the bias power source 3, and the surface of the substrate 7 is bombarded with argon gas to be cleaned.

  If the substrate temperature is less than 250 ° C., there is no etching effect by argon gas, and if it exceeds 650 ° C., it is difficult to set the substrate temperature to a predetermined condition during the film forming process. The substrate temperature is measured by a thermocouple embedded in the substrate. If the pressure of the argon gas in the decompression vessel 5 is outside the range of 0.5 to 10 Pa, the bombardment process using the argon gas becomes unstable. When the DC bias voltage or pulse bias voltage is less than −250 V, arcing occurs in the substrate, and when it exceeds −150 V, the cleaning effect by bombard etching cannot be sufficiently obtained.

(B) Modified layer forming step Ion bombardment to the WC-based cemented carbide substrate 7 using the modified layer forming TiB target is performed in an argon gas atmosphere with a flow rate of 50 to 100 sccm after the substrate 7 is cleaned. Then, a modified layer is formed on the surface of the substrate 7. An arc current (DC current) of 120 to 200 A is supplied from the arc discharge power supply 11 to the surface of the TiB target attached to the arc discharge evaporation source 13. The substrate 7 is heated to a temperature of 450 to 620 ° C., and a DC bias voltage of −1000 to −700 V is applied to the substrate 7 from the bias power source 3. Ti ions and B ions are irradiated onto the WC-based cemented carbide substrate 7 by ion bombardment using a TiB target.

  If the temperature of the substrate 7 is outside the range of 450 to 620 ° C., a modified layer having an fcc structure is not formed, or a decarburized layer is formed on the surface of the substrate 7 and the performance is significantly lowered. If the flow rate of the argon gas in the decompression vessel 5 is less than 50 sccm, the energy of Ti ions incident on the substrate 7 is too strong, and a decarburized layer is formed on the surface of the substrate 7, thereby impairing the adhesion of the hard coating. On the other hand, when the flow rate of argon gas exceeds 100 sccm, the energy of Ti ions or the like is weakened and the modified layer is not formed.

  When the arc current is less than 120 A, the arc discharge becomes unstable, and when it exceeds 200 A, a large number of droplets are formed on the surface of the substrate 7 and the adhesion of the hard coating is impaired. When the DC bias voltage is less than −1000 V, energy such as Ti ions is too strong, and a decarburized layer is formed on the surface of the substrate 7, and when it exceeds −700 V, a modified layer is not formed on the substrate surface.

(C) (AlTiVNi) N Hard Film Formation Process An (AlTiVNi) N hard film is formed on the substrate 7 (or on the modified layer if formed). At this time, using a nitriding gas, an arc current is applied to the surface of the target 18 attached to the arc discharge evaporation source 27 from the arc discharge power source 12 under the conditions described later. At the same time, a DC bias voltage or a unipolar pulse bias voltage is applied from the bias power source 3 to the substrate 7 controlled to a predetermined temperature.

(1) Substrate temperature
The substrate temperature is preferably set to 450 to 550 ° C. during the formation of the (AlTiVNi) N hard coating. When the substrate temperature is less than 450 ° C., (AlTiVNi) N does not crystallize sufficiently, so that the (AlTiVNi) N hard film does not have sufficient wear resistance, and the increase in residual stress causes film peeling. On the other hand, if the substrate temperature exceeds 550 ° C., the refinement of crystal grains is promoted and the wear resistance is impaired. The substrate temperature is more preferably 500 to 520 ° C.

(2) Type and pressure of nitriding gas As a nitriding gas for forming the (AlTiVNi) N hard coating of the present invention on the substrate 7, for example, nitrogen gas, a mixed gas of ammonia gas and hydrogen gas, or the like can be used. . The pressure of the nitriding gas is preferably 2.5 to 5 Pa. When the pressure of the nitriding gas is less than 2.5 Pa, nitriding of the hard film is insufficient and wear resistance is impaired. On the other hand, even if the pressure of the nitriding gas exceeds 5 Pa, the effect of adding the nitriding gas is saturated and an improvement in the effect corresponding to the pressure increase cannot be expected.

(3) Bias voltage applied to the substrate
In order to form the (AlTiVNi) N hard film, a DC bias voltage or a unipolar pulse bias voltage is applied to the substrate. The DC bias voltage is negative and is preferably −150 to −40 V. When the DC bias voltage is less than −150 V, arcing or reverse sputtering occurs on the substrate, and the productivity is significantly reduced. On the other hand, if the DC bias voltage exceeds -40 V, the effect of applying the bias voltage is insufficient, and a hexagonal lattice structure is formed in the hard coating, resulting in deterioration of wear resistance. A preferable range of the DC bias voltage is −130 to −80 V.

  In the case of a unipolar pulse bias voltage, the negative bias voltage (negative peak value excluding a portion with a sharp rise from zero to the negative side) is set to −150 to −40 V. Outside this range, the (AlTiVNi) N hard coating of the present invention cannot be obtained. A preferred range for the negative bias voltage is -130 to -80 V. The frequency of the unipolar pulse bias voltage is preferably 20 to 50 kHz, and more preferably 30 to 40 kHz.

(4) Arc current
In order to suppress droplets during the formation of the (AlTiVNi) N hard coating, a direct current arc current is applied to the (AlTiVNi) N hard coating forming target 18. The DC arc current is preferably 150 to 200 A. If the DC arc current is less than 150 A, the discharge becomes unstable and it becomes difficult to form an (AlTiVNi) N hard coating. On the other hand, when the DC arc current exceeds 200 A, the elements contained in the target are not ionized and become droplets, so that Ni and V oxides are not formed in the film, and wear resistance deteriorates.

  The present invention will be described in more detail with reference to the following examples, but the present invention is of course not limited thereto. In the following examples and comparative examples, the target composition is a value measured by chemical analysis unless otherwise specified. In the embodiments, the insert is used as the base of the hard coating. However, the present invention is of course not limited thereto, and can be applied to cutting tools other than the insert (end mill, drill, etc.) or a die. .

Example 1
(1) Cleaning the substrate
Finished milling insert base body made of WC-base cemented carbide containing 8.0% by mass of Co and the balance consisting of WC and inevitable impurities (ZDFG300-ST made by Mitsubishi Hitachi Tool Co., Ltd. having the shape shown in FIG. 14) ), And an insert substrate for measuring physical properties (SNMN120408 manufactured by Mitsubishi Hitachi Tool Co., Ltd.) is set on the holder 8 of the AI device shown in FIG. 1, and heated to 550 ° C. with a heater (not shown) simultaneously with evacuation. did. Thereafter, argon gas was introduced at a flow rate of 500 sccm (cc / min at 1 atm and 25 ° C.) to adjust the pressure in the vacuum vessel 5 to 2.0 Pa, and a negative DC bias voltage of −200 V was applied to each substrate. Each substrate was cleaned by etching with argon ion bombardment.

(2) Formation of a modified layer using a TiB target While maintaining the substrate temperature at 550 ° C, the argon gas flow rate was set to 70 sccm, and the target 10 having a composition represented by Ti _0.8 B _0.2 in terms of atomic ratio was arced. Arranged in an arc discharge evaporation source 13 to which a power source 11 for operation is connected. A negative DC voltage of −800 V was applied to each substrate by the bias power source 3, and a DC arc current of 175 A from the arc discharge power source 11 was applied to the surface of the target 10 to form a modified layer on the surface of each substrate. .

(3) Formation of (AlTiVNi) N Hard Film The substrate temperature was set to 520 ° C., nitrogen gas was introduced at 900 sccm, and the pressure in the vacuum vessel 5 was adjusted to 3.5 Pa. A sintered alloy target 18 having a composition represented by an atomic ratio of Al _0.634 Ti _0.312 V _0.019 Ni _0.010 N _0.004 O _0.021 was placed in an arc discharge evaporation source 27 to which an arc discharge power source 12 was connected.

A negative DC voltage of −120 V was applied to each substrate by the bias power source 3, and a 180 A DC arc current was applied to the surface of the target 18 from the arc discharge power source 12 to _obtain an atomic ratio (Al _0.630 Ti _0.340 V _0.023 Ni _0.007 ) _0.58 N A film having a thickness of 3.5 μm having a composition represented by _0.42 was formed. The film composition was measured with an electron probe microanalyzer EPMA (JXA-8500F manufactured by JEOL Ltd.) at the center position in the thickness direction of the film under the conditions of an acceleration voltage of 10 kV, an irradiation current of 0.05 A, and a beam diameter of 0.5 μm. .

  FIG. 2 is an SEM photograph (magnification: 25,000 times) showing a cross-sectional structure of the obtained (AlTiVNi) N hard film-coated milling insert. In FIG. 2, 41 indicates a WC-based cemented carbide substrate, and 42 indicates an (AlTiVNi) N hard coating.

(4) Combined state of Al, Ti, V and Ni in (AlTiVNi) N hard coating
Using an X-ray photoelectron spectrometer (Quantum 2000 type manufactured by PHI), after etching the (AlTiVNi) N hard film to half the depth from the surface with argon ions, AlK _α1 rays (wavelength λ: 0.833934 nm) was obtained, and X-ray photoelectron spectroscopy spectra of FIGS. 3 to 6 showing the bonding states of Al, Ti, V, and Ni were obtained. 3 to 6, the horizontal axis represents binding energy (eV), and the vertical axis represents c / s (counts per second).

  FIG. 3 shows the peak of Al—N. From the X-ray photoelectron spectroscopy spectrum of FIG. 3, no Al—O bonds were observed, and only Al—N bonds were observed.

  FIG. 4 shows TiNxOy and Ti-N peaks. Although the exact ratio of x and y in TiNxOy is unknown from the X-ray photoelectron spectroscopy spectrum in Fig. 4, the compositional analysis value of (AlTiVNi) N hard coating by EPMA analysis (Table 5-1) indicates that TiNxOy is Ti nitride. It can be seen that the main subject.

As shown in FIG. 5, peaks of VN, V ₂ O ₃ , and V ₂ O ₅ were observed in the X-ray photoelectron spectrum of V, but metal V was not observed. FIG. 5 shows that V is an oxide and a nitride.

As shown in FIG. 6, peaks of metals Ni, NiN, NiO, and Ni ₂ O ₃ were observed in the X-ray photoelectron spectrum of Ni. Since there is a large Ni ₂ O ₃ peak, it can be seen that Ni is mainly composed of oxide. The NiO peak also partly overlapped with the Ni ₂ O ₃ peak. NiN and Ni were slightly present.

(5) X-ray diffraction pattern of (AlTiVNi) N hard film X-ray diffractometer (EMPYREAN made by Panalytical) was used to measure the crystal structure and crystal orientation of (AlTiVNi) N hard film on the above-mentioned insert substrate for measuring physical properties. ) Was irradiated with CuK _α1 rays (wavelength λ: 0.15405 nm) to obtain an X-ray diffraction pattern (FIG. 7) under the following conditions.
Tube voltage: 45 kV
Tube current: 40 mA
Incident angle ω: Fixed at 3 °
2θ: 30 ~ 90 °

  In FIG. 7, the (111) plane, (200) plane, (220) plane, (311) plane, and (222) plane are all X-ray diffraction peaks of the rock salt structure of the (AlTiVNi) N hard coating. Therefore, it can be seen that the (AlTiVNi) N hard coating of Example 1 has a rock salt type single structure.

Table 1 shows standard X-ray diffraction intensities I ₀ and 2θ of TiN described in ICCD reference code 00-006-0642. TiN has the same rock salt structure as (AlTiVNi) N. In the (AlTiVNi) N hard coating of the present invention, a part of TiN Ti is replaced with Al, V, and Ni, so the numerical values shown in Table 1 are adopted as the standard X-ray diffraction intensity I ₀ (hkl).

  Table 2 shows the X-ray diffraction intensity (measured value) and X-ray diffraction peak intensity ratio (based on the (200) plane, which is the strongest peak plane of X-ray diffraction), from the X-ray diffraction pattern of FIG. In Table 2, the peak angle 2θ of the (AlTiVNi) N hard coating is shifted to a higher angle than in Table 1.Since other elements such as Al are added to TiN, the strain in the (AlTiVNi) N hard coating is This is thought to be due to the occurrence of

(6) Microstructure and composition of (AlTiVNi) N hard coating The cross section of the (AlTiVNi) N hard coating of the above-mentioned insert for measuring physical properties was observed by TEM (JEM-2100 manufactured by JEOL Ltd.). FIG. 8 shows a TEM photograph (magnification 16,000 times, field of view: 7 μm × 7 μm) of the obtained (AlTiVNi) N hard coating. Further, FIG. 9 shows a TEM bright field image (magnification: 1,600,000 times, field of view: 740 nm × 740 nm) in which the outer shell 43a of the droplet 43 of FIG. 8 is enlarged. Furthermore, for the matrix 42a of the (AlTiVNi) N hard coating 42 and the outer shell 43a of the droplet 43, using a UTW type Si (Li) semiconductor detector attached to the JEM-2100, a beam diameter of 1 nm is required. The energy dispersive X-ray analysis was performed. 10-1 shows the energy dispersive X-ray spectrum of the matrix 42a of the (AlTiVNi) N hard coating 42, and FIG. 10-2 shows the energy dispersive X-ray spectrum of the outer shell portion 43a of the droplet 43. In FIGS. 10-1 and 10-2, the horizontal axis is keV, and the vertical axis is Counts (integrated intensity). Table 3 shows composition analysis values of the matrix 42a of the (AlTiVNi) N hard coating 42 and the outer shell portion 43a of the droplet 43 obtained by energy dispersive X-ray analysis.

  From Table 3 and FIG. 10-1, it can be seen that the matrix 42a of the (AlTiVNi) N hard coating 42 does not contain oxygen and is made of (AlTiVNi) N. Further, since Ni is contained in the matrix 42a and O is not detected, it can be said that Ni is dissolved without being oxidized. On the other hand, it can be seen from Table 3 and FIG. 10-2 that the outer shell portion 43a of the droplet 43 is made of an oxide mainly composed of Ni and Al that are not nitrided.

  Using JEM-2100, limited field diffraction measurement was performed on the matrix 42a of the (AlTiVNi) N hard coating 42 under the conditions of an acceleration voltage of 200 kV and a camera length of 50 cm. The obtained limited field diffraction image is shown in FIG. In FIG. 11, the (111) plane of the fcc structure [denoted as fcc (111) in FIG. The same applies to the other (hkl) surfaces. ], The (200) plane, the (220) plane, and the (002) plane of the hcp structure (denoted as hcp (002) in FIG. 11), the matrix 42a of the (AlTiVNi) N hard coating 42 has an fcc structure. Is the main structure, and the hcp structure is the substructure. Further, an FFT pattern was obtained for the outer shell portion 43a of the droplet 43 using a fast Fourier transform device (FFT, Digital Micrograph manufactured by Gatan). The obtained FFT pattern is shown in FIG. In FIG. 12, the (200) plane of the fcc structure [described as fcc (200) in FIG. The same applies to the other (hkl) surfaces. ] And (020) plane were observed, it can be seen that the droplet 43 has a rock salt structure.

(7) Measurement of Droplet FIG. 13 is an SEM photograph (magnification: 3,000 times) showing the surface of the (AlTiVNi) N hard film of the insert for measuring physical properties. As a result of counting droplets having a diameter of 1 μm or more in the field of view of 30 μm length × 40 μm width of this SEM photograph, the number of droplets on the surface of the (AlTiVNi) N hard coating of Example 1 is 10 per field, which will be described later. It can be seen that it is much less than the surface of the (AlTiVNi) N hard coating of Comparative Example 1 (FIG. 16).

(8) Measurement of tool life As shown in FIG. 15, the (AlTiVNi) N hard coating coated milling insert 30 is replaced with the tip 38 of the tool main body 36 of the blade-changeable rotary tool (ABPF30S32L150 manufactured by Mitsubishi Hitachi Tool Co., Ltd.) 40. It was attached with setscrew 37. The blade diameter of the blade-tip replaceable rotary tool 40 was 30 mm. Cutting was performed under the following rolling conditions, and the flank face of the insert 30 sampled every unit time was observed with an optical microscope (magnification: 100 times), and the wear width or chipping width of the flank face was 0.2 mm or more. The machining time was determined as the tool life.

Cutting conditions Machining method: High-feed continuous rolling Work material: SKD11 square material (HRC60) measuring 120 mm x 250 mm
Insert used: ZDFG300-ST (for milling)
Cutting tool: ABPF30S32L150
Cutting speed: 230 m / min
Feed per tooth: 0.3 mm / tooth Axial cut depth: 0.5 mm
Radial depth of cut: 0.4 mm
Cutting fluid: None (dry machining)

  The composition of the used (AlTiVNi) N hard film forming target and the sintered body composition are shown in Table 4-1 and Table 4-2, respectively, and the composition of the (AlTiVNi) N hard film is shown in Table 5-1, Table 5-2 shows the crystal structure, Ni-O bond, VO bond, Al-O bond, and tool life of the (AlTiVNi) N hard coating.

Examples 2-13
Each (AlTiVNi) N hard material in the milling insert is the same as in Example 1 except that the composition and sintered body composition of the (AlTiVNi) N hard film forming target shown in Table 4-1 and Table 4-2 are used. A film was formed.

Comparative Example 1
A hard coating was formed on the milling insert in the same manner as in Example 1 except that the composition and sintered body composition (Table 4-1 and Table 4-2) of the target to which TiN and VN were not added were adopted.

Comparative Example 2
A hard coating was applied to the milling insert in the same manner as in Example 1 except that a sintered target having an excessive oxygen content [O (η) = 0.080] with a hot press temperature of 550 ° C. and a vacuum of 100 Pa was prepared. Formed.

Comparative Example 3
Hard to milling insert in the same manner as in Example 1 except that a sintered compact target with a low oxygen content [O (η) = 0.010] was prepared with a hot press temperature of 550 ° C. and a vacuum of 0.04 Pa. A film was formed. Here, O (η) = 0.010 corresponds to the upper limit of the inevitable impurity level.

Conventional example 1
A hard film was formed on the milling insert in the same manner as in Example 1 except that the composition of the target to which TiN, VN and Ni were not added and the sintered body composition (Tables 4-1 and 4-2) were adopted.

Conventional example 2
A hard coating was formed on the milling insert in the same manner as in Example 1 except that the composition of the target to which TiN, VN and V were not added and the sintered body composition (Tables 4-1 and 4-2) were adopted.

  The composition and crystal structure, Ni—O bond, V—O bond and Al—O bond, and tool life were measured for the hard coatings of Examples 2 to 13, Comparative Examples 1 to 3, and Conventional Examples 1 and 2. The composition of the hard coating is shown in Table 5-1, and the crystal structure, Ni—O bond, V—O bond, Al—O bond presence, and tool life are shown in Table 5-2.

  From Table 5-2, it can be seen that the (AlTiVNi) N hard coatings of Examples 1 to 13 all have Ni—O bonds and V—O bonds, and no Al—O bonds. For this reason, the tool life of each cutting tool of Examples 1 to 13 was as long as 280 minutes or more. On the other hand, in the (AlTiVNi) N hard coating of Comparative Example 1 using a target not added with TiN and VN, Ni-O bonds and VO bonds were not formed, and the tool life was as short as 110 minutes. . The (AlTiVNi) N hard film of Comparative Example 2 using an excessively sintered target with an oxygen content O (η) of 0.080 has formed a harmful Al-O bond together with a Ni-O bond and a VO bond. Tool life was as short as 100 minutes. The (AlTiVNi) N hard coating of Comparative Example 3 using a sintered compact target with an oxygen content O (η) of 0.010 and too low has no Ni-O bond or VO bond, and the tool life is 115 minutes. It was short. Further, as shown in FIG. 16, a large number of droplets were formed on the hard film of Comparative Example 1, and the number of droplets having a diameter of 1 μm or more measured in the same manner as in Example 1 was 22 / field of view. . Such a large number of droplets is considered to be the reason for the short life of the cutting tool of Comparative Example 1.

  Conventional (AlTiV) N hard coating of Example 1 using a target without addition of TiN, VN and Ni, and (AlTiNi) N hard coating of Conventional Example 2 using a target without addition of TiN, VN and V In either case, Ni-O bonds and VO bonds were not formed, and the tool life was as short as 110 minutes and 120 minutes.

Note: (1) The metal component is AlTiV.
(2) The metal component is AlTiNi.

Note: (3) Single structure.
(4) Main structure.

Examples 14 and 15
(AlTiVNi) N Nitrogen gas pressure during hard film formation
A hard coating was formed on each milling insert in the same manner as in Example 1, except that the pressure of nitrogen gas during the formation of (AlTiVNi) N hard coating was 2.5 Pa (Example 14) and 5 Pa (Example 15), respectively. ,evaluated. The measurement results of the pressure of nitrogen gas, the composition of the (AlTiVNi) N hard coating, and the tool life are shown in Table 6 together with the measurement results of Example 1.

  As is apparent from Table 6, the tool life of Examples 14 and 15 in which the pressure of nitrogen gas during the formation of the (AlTiVNi) N hard film was 2.5 Pa and 5 Pa was as long as 295 minutes or more.

Examples 16 and 17
(AlTiVNi) N substrate temperature when forming hard coating
(AlTiVNi) N The substrate temperature at the time of hard coating formation was 450 ° C. in Example 16, and 550 ° C. in Example 17 to form a hard coating on each milling insert in the same manner as in Example 1, and the composition and Tool life was measured. The measurement results are shown in Table 7 together with Example 1.

  As apparent from Table 7, the tool life of Examples 16 and 17 in which the substrate temperature was 450 ° C. and 550 ° C. was as long as 300 minutes or more.

Examples 18-22
Bias voltage when forming (AlTiVNi) N hard coating
(AlTiVNi) N Bias voltage when forming hard coating is DC voltage -90 V (Example 18), DC voltage -150 V (Example 19), Unipolar pulse bias voltage -120 V (Example 20), Unipolar pulse, respectively. A hard film was formed on each milling insert in the same manner as in Example 1 except that the bias voltage was −90 V (Example 21) and the unipolar pulse bias voltage was −150 V (Example 22). It was measured. The measurement results are shown in Table 8 together with Example 1.

Note: (5) DC bias voltage.
(6) Unipolar pulse bias voltage.

  From Table 8, the tool life of Examples 18 and 19 with DC voltages of −90 V and 150 V and Examples 20 to 22 with unipolar pulse bias voltages of −120 V, −90 V and 150 V was as long as 295 minutes or more. .

Examples 23 and 24
DC arc current when forming (AlTiVNi) N hard coating
(AlTiVNi) N DC arc current at the time of hard film formation was set to 150 A in Example 23 and 200 A in Example 24, except that a hard film was formed on each milling insert in the same manner as in Example 1, and the composition And tool life was measured. The measurement results are shown in Table 9 together with Example 1.

  From Table 9, the tool life of Examples 23 and 24 in which the DC arc current was 150 A and 200 A was as long as 300 minutes or more.

Examples 25-28
Film thickness of (AlTiVNi) N hard coating
The thickness of the (AlTiVNi) N hard coating was 1 μm in Example 25, 6 μm in Example 26, 8 μm in Example 27, 10 μm in Example 28, and each milling as in Example 1. A hard film was formed on the insert, and the composition and tool life were measured. The measurement results are shown in Table 10 together with Example 1.

  As is apparent from Table 10, the tool life of Examples 25 to 28 in which the thickness of the (AlTiVNi) N hard coating was 1 to 10 μm was as long as 280 minutes or more.

Examples 29-40
Middle class
In order to investigate the effect of the intermediate layer on the lifetime of the (AlTiVNi) N hard coating, between the modified layer and the (AlTiVNi) N hard coating as in Example 1, each target having the composition shown in Table 11 and each film formation A (AlTiVNi) N hard coating was formed on each milling insert in the same manner as in Example 1 except that each intermediate layer was formed by physical vapor deposition using the conditions, and the composition and tool life were measured. The measurement results are shown in Table 12 together with Example 1.

Note: (7) It has a rock salt type single structure by X-ray diffraction.

  In Examples 29 to 40, between the WC-based cemented carbide substrate and the (AlTiVNi) N hard coating, at least selected from the group consisting of elements 4a, 5a and 6a, Al and Si by physical vapor deposition An intermediate layer (hard film) was formed with one metal element and at least one element selected from the group consisting of B, O, C, and N as essential constituent elements. The tool also had a good tool life of over 280 minutes.

1: Drive unit
2: Gas introduction part
3: Bias power supply
4: Bearing part
5: Vacuum container
6: Lower holder (support)
7: Base
8: Upper holder
10, 18: Cathode material (target)
11, 12: Arc discharge power supply
13, 27: Arc discharge evaporation source
14: Insulator for fixing arc discharge evaporation source
15: Arc ignition mechanism bearing
16: Arc ignition mechanism
17: Exhaust port
19: Insulator for fixing electrodes
20: Electrode
21: Shield plate bearing
22: Shield plate drive
23: Shield plate
30: Insert for milling
35: Rake face of insert
36: Tool body
37: Insert set screw
38: Tip of tool body
40: Blade-changeable rotary tool
41: WC-based cemented carbide substrate
42: (AlTiVNi) N hard coating
42a: (AlTiVNi) N hard coating matrix
43: Droplet
43a: Droplet shell

Claims (10)

(Al _a Ti _b V _c Ni _d ) _(1-p) N _p (where a, b, c, d and p are atomic ratios, 0.45 ≦ a ≦ 0.8, 0.15 ≦ b ≦ 0.5, 0.01 ≦ c, respectively) ≦ 0.05, 0.001 ≦ d ≦ 0.01, a + b + c + d = 1, and 0.2 ≦ p ≦ 0.8)),
Rigidity characterized by having an X-ray diffraction pattern consisting of a single salt-type structure with Ni-O bonds substantially without Al-O bonds in the bonding state specified by X-ray photoelectron spectroscopy Film.   2. The hard film according to claim 1, wherein the bonding state specified by X-ray photoelectron spectroscopy further has a V—O bond. In the hard film of claim 1 or 2, wherein the hard coating has a droplet made of an oxide containing Ni, Ti, and Al mandatory, the composition of the _{droplet, (M e Ni 1-e} ) _(1-q) O _q (where M represents Ti and Al, or Ti, Al and V, and e and q are atomic ratios and satisfy 0.2 ≦ e ≦ 0.8 and 0.05 ≦ q ≦ 0.35, respectively) A hard film characterized by the following:   4. The hard film according to claim 1, wherein the electron diffraction pattern of the hard film has a rock salt structure as a main structure and a wurtzite structure as a sub structure.   5. A hard coating-coated member, wherein the hard coating according to claim 1 is formed on a substrate.   6. The hard film-coated member according to claim 5, wherein at least one metal element selected from the group consisting of elements 4a, 5a and 6a, Al and Si, between the base and the hard film, and B A hard coating member characterized by having an intermediate layer essentially containing at least one element selected from the group consisting of O, C, and N. (Al _a Ti _b V _c Ni _d ) _(1-p) N _p (where a, b, c, d and p are atomic ratios, 0.45 ≦ a ≦ 0.8, 0.15 ≦ b ≦ 0.5, 0.01 ≦ c, respectively) ≦ 0.05, 0.001 ≦ d ≦ 0.01, a + b + c + d = 1, and 0.2 ≦ p ≦ 0.8), and the binding state specified by X-ray photoelectron spectroscopy is substantially Al- A method of manufacturing a hard coating coated member in which a hard coating having an X-ray diffraction pattern composed of a rock salt type single structure without an O bond and having a rock salt type single structure is formed on a substrate by an arc ion plating method. ,
In a nitriding gas atmosphere, Al _α Ti _β V _γ Ni _δ N _ε O _η (where α, β, γ, δ, ε and η are atomic ratios of Al, Ti, V, Ni, N and O, respectively) 0.45 ≦ α ≦ 0.80, 0.15 ≦ β ≦ 0.48, 0.01 ≦ γ ≦ 0.05, 0.003 ≦ δ ≦ 0.015, 0.015 ≦ ε ≦ 0.01, 0.015 ≦ η ≦ 0.05, and α + β + γ + δ + ε + η = 1. A method comprising using an alloy target comprising: In the method for producing a hard film-coated member according to claim 7,
When forming the hard film on the substrate maintained at a temperature of 450 to 550 ° C. in a nitriding gas atmosphere of 2.5 to 5 Pa, a DC bias voltage or a unipolar pulse bias voltage of −150 to −40 V is applied to the substrate. And applying a direct current arc current of 150 to 200 A to the target provided in the arc discharge evaporation source. In the target for forming a hard film according to any one of claims 1 to 4, Al _α Ti _β V _γ Ni _δ N _ε O _η (where α, β, γ, δ, ε, and η are Al, Ti, At atomic ratio of V, Ni, N and O, 0.45 ≦ α ≦ 0.80, 0.15 ≦ β ≦ 0.48, 0.01 ≦ γ ≦ 0.05, 0.003 ≦ δ ≦ 0.015, 0.001 ≦ ε ≦ 0.01, 0.015 ≦ η ≦ 0.05, and α + β + γ + δ + ε + η = 1). A target comprising a sintered alloy having a composition represented by:   10. The target according to claim 9, wherein the sintered body is a reduced pressure at a temperature of 520 to 580 ° C. and a pressure of 1 to 10 Pa using a mixed powder composed of Al powder, Ti powder, TiN powder, V powder, VN powder, and Ni powder. A target obtained by hot pressing in an atmosphere.