JP6520682B2 - Hard coated tool and method of manufacturing the same - Google Patents

Description

  The present invention relates to a hard-coated tool having a titanium aluminum nitride film excellent in heat resistance and peel resistance, and a method of manufacturing the same.

  BACKGROUND ART A cutting tool in which a hard coating such as TiAlN, TiC, TiN, Ti (CN) or the like is coated in a single layer or a plurality of layers has conventionally been used for cutting of mild steel or the like. However, under increasingly severe cutting conditions, there is a problem that the film is oxidized and the life is shortened. There are also attempts to cool the cutting edge by changing from dry processing to wet processing to extend the tool life, but heat cracking occurs due to heating and cooling cycles, and the life is difficult to extend due to peeling from that point . In order to solve such a problem, a cutting tool having a hard coating excellent in heat resistance and peeling resistance is desired.

  Japanese Patent No. 3560303 (Patent Document 1) discloses an inner layer film by forming a bonding layer such as TiCN / TiCNO between an inner layer film such as TiC, TiN, TiCN, etc. and an oxide film mainly composed of α-type aluminum oxide. A coated cutting tool is disclosed in which adhesion is improved by connecting plaids continuously at both interfaces between the bonding layer and the bonding layer and the oxide film. However, when a titanium aluminum nitride hard coating is provided immediately above the bonding layer under the film forming conditions described in Patent Document 1, the lattice stripes become discontinuous at the boundary (interface) between the bonding layer and the titanium aluminum nitride hard coating, Therefore, it does not meet the demanding performance requirements of recent cutting tools.

JP-A-2001-341008 (PTD 2) uses titanium halide gas, aluminum halide gas and NH ₃ gas as a source gas, and heats the surface of a WC-based cemented carbide substrate by a thermal CVD method at 700 to 900 ° C. Disclosed is a coated cutting tool having a titanium aluminum nitride film of fcc structure containing ̃2% by mass of chlorine. However, when a TiN film and a titanium aluminum nitride film are formed on the surface of the cemented carbide substrate under the film forming conditions described in the example of Patent Document 2, the crystal lattice is discontinuous at the interface between the TiN film and the titanium aluminum nitride film. Tool performance is reduced.

Japanese Patent Laid-Open No. 2014-129562 (Patent Document 3) discloses a tool coated with a titanium aluminum nitride film having a multilayer structure using the CVD apparatus 100 shown in FIG. The CVD apparatus 100 has a plurality of shelves 103 for mounting a plurality of substrates 102, a reaction container 104 for covering the shelves 103, a temperature control device 105 surrounding the reaction container 104, and an introduction having two inlets 106 and 107. A pipe 108 and an exhaust pipe 109 are provided. The titanium aluminum nitride film has a structure in which first unit layers and second unit layers made of hard particles of TiAlN, AlN or TiN are alternately laminated on the surface of a WC base cemented carbide substrate. This is because (1) the first and second source gases (mixed gas) are ejected from the nozzles provided at the same distance from the center of the introduction pipe 108 in the opposite direction (180 °) into the furnace and (2) The reaction rate of the source gas is very slow because the content of the NH ₃ gas in the second source gas is as very small as 0.09 mol / min. However, when a titanium nitride film and a titanium aluminum nitride film are formed on the surface of the WC-based cemented carbide substrate under the film forming conditions described in the example of Patent Document 3, the bonding according to the present invention is performed as in Comparative Example 1 described later. No layer is formed and the resulting cutting tool has a short life.

Patent 3560303 JP 2001-341008 A JP 2014-129562 A

  Therefore, it is an object of the present invention that at least 30% or more of the lattice is continuous at the interface between the lower layer such as titanium mononitride etc. and the bonding layer consisting of Ti-rich titanium aluminum nitride film and the bonding layer and Al-rich titanium nitride It is to provide a hard-coated tool having a titanium aluminum nitride film excellent in heat resistance and peeling resistance by having 30% or more of a plaid continuous at the interface with an aluminum film, and a method of manufacturing the same.

The hard-coated tool according to the present invention comprises a tool substrate having a lower layer of fcc structure comprising a single layer film of titanium carbonitride, titanium nitride and titanium zirconium carbonitride by chemical vapor deposition or any one or more multilayer films. , Ti _{x 1} Al _{y 1} N (wherein x 1 and y 1 are numbers satisfying atomic ratios x 1 = 0.45 to 0.05, y 1 = 0.55 to 0.95, and x 1 + y 1 = 1), respectively. A hard film having a titanium aluminum nitride film is formed, and a bonding layer is provided between the lower layer and the titanium aluminum nitride film, and the bonding layer is formed of Ti _{x 2} Al _{y 2} N (where x 2 and y 2 are each It has a composition and an fcc structure represented by the atomic ratio x 2 = 0.55 to 0.80, y 2 = 0.45 to 0.20, and x 2 + y 2 = 1), and 30% at the interface between the lower layer and the bonding layer While the above plaid is continuous, the bonding layer and the nitrogen Wherein the interface at least 30% of the plaid titanium aluminum coating is continuous.

  The layer thickness of the bonding layer is preferably 2 to 50 nm.

The method of the present invention for producing the above hard-coated tool comprises
(1) chemical vapor deposition apparatus mounted with the tool substrate, mixed consisting of (a) TiCl ₄ gas, AlCl ₃ gas, a mixed gas A ₁ consisting of N ₂ gas and H ₂ gas, N ₂ gas and H ₂ gas after supplying a first material gas consisting of the gas B ₁ Tokyo, (b) TiCl ₄ gas, AlCl ₃ gas, a mixed gas a ₂ consisting of N ₂ gas and H ₂ gas, NH ₃ gas, N ₂ gas and by supplying the second material gas comprising a mixed gas B ₂ Metropolitan consisting H ₂ gas, to form the bond layer, then
(2) TiCl ₄ gas, AlCl ₃ gas, a mixed gas A ₃ consisting of N ₂ gas and H ₂ gas, the third material consisting of NH ₃ gas, consisting of N ₂ gas and H ₂ gas mixed gas B ₃ Metropolitan The titanium aluminum nitride film is formed by supplying a gas.

The first source gas is 0.18 to 0.77% by volume of TiCl ₄ gas, 0.06 to 0.35% by volume of AlCl ₃ gas, wherein the total of TiCl ₄ gas, AlCl ₃ gas, N ₂ gas and H ₂ gas is 100% by volume. , 4-15% by volume of N ₂ gas, and the mixed gas a ₁ the balance being H ₂ gas, that consists of 4 to 15% by volume of N ₂ gas, and the mixed gas B ₁ Metropolitan balance consisting H ₂ gas preferable.

The second source gas includes 0.18 to 0.77% by volume of TiCl ₄ gas, 0.06 to 0.35% by volume, where the total of TiCl ₄ gas, AlCl ₃ gas, NH ₃ gas, N ₂ gas and H ₂ gas is 100% by volume. AlCl ₃ gas, 4-15% by volume of N ₂ gas, and the mixed gas a ₂ the balance being H ₂ gas, 0.85 to 1.5% by volume of NH ₃ gas, 4-15% by volume of N ₂ gas, and the balance preferably, a mixed gas B ₂ Metropolitan consisting H ₂ gas.

The third source gas is composed of TiCl ₄ gas, AlCl ₃ gas, NH ₃ gas, N ₂ gas and H ₂ gas in total of 100% by volume, 0.02 to 0.31% by volume of TiCl ₄ gas, 0.15 to 0.8% by volume AlCl ₃ gas, 4.9 to 21.8% by volume of N ₂ gas, and the mixed gas a ₃ the balance being H ₂ gas, 0.7 to 1.9% by volume of NH ₃ gas, 3 to 16.5% by volume of N ₂ gas, and the balance preferably, a mixed gas B ₃ Metropolitan consisting H ₂ gas.

The method of the present invention uses a chemical vapor deposition apparatus comprising first and second pipes rotating about an axis of rotation O, said first pipe having a first nozzle, said second pipe has a second nozzle, the distance H ₁ between the rotation axis O between the gas jetting port of the first nozzle longer than the distance of H ₂ and the rotary shaft O and spout of said second nozzle, It is preferable that the mixed gases A ₁ , A ₂ and A ₃ are sequentially ejected from the first nozzle, and the mixed gases B ₁ , B ₂ and B ₃ are sequentially ejected from the second pipe.

Preferably the ratio of the distance H ₁ between the distance H ₂ of (H ₁ / H ₂₎ in the range of 1.5 to 3.

  The process according to the invention is preferably carried out at a reaction pressure of 3 to 6 kPa and a reaction temperature of 750 to 830 ° C.

  The hard-coated tool according to the present invention comprises a lower layer of fcc structure, a bonding layer comprising a Ti-rich titanium aluminum nitride film, and an Al-rich titanium aluminum nitride film formed through the bonding layer. And 30% or more of the lattice is continuous at the interface between the lower layer and the bonding layer, and 30% or more of the lattice is continuous at the interface between the bonding layer and the titanium aluminum nitride film. Has excellent heat resistance and peeling resistance, and has a long tool life.

It is a scanning electron microscope (SEM) photograph (10,000 magnification) which shows the cross section of the hard-film coated tool of Example 1. FIG. 1 is a transmission electron microscope (TEM) photograph (magnification 4,000,000) showing the cross section of the hard-coated tool of Example 1. FIG. It is the schematic of the TEM photograph of FIG. FIG. 5 is a schematic view showing a method of determining an average thickness of a bonding layer. 2 is a photograph showing a nanobeam diffraction image (NAD) of the bonding layer of Example 1. FIG. It is a schematic diagram which shows an example of the chemical vapor deposition apparatus (CVD furnace) which can be used for formation of the hard film of this invention. FIG. 6 is a cross-sectional view showing an example of an integral pipe assembly including the first and second pipes. FIG. 7 is a cross-sectional view of another example of an integral pipe assembly comprising first and second pipes. FIG. 7 is a cross-sectional view showing still another example of an integral pipe assembly including the first and second pipes. It is the schematic which shows the planar shape of the insert for milling. It is the schematic which shows the blade-tip-exchange-type rotary tool which mounts the insert of FIG. It is a cross-sectional view which shows the integral pipe assembly which has a source gas jet nozzle in the same direction as the apparatus of Unexamined-Japanese-Patent No. 2014-129562. It is the schematic which shows the CVD apparatus of Unexamined-Japanese-Patent No. 2014-129562.

[1] Hard-Coated Tool The hard-coated tool of the present invention is a tool substrate comprising a single-layer coating of titanium carbonitride, titanium nitride and titanium zirconium carbonitride by chemical vapor deposition, or a multilayer coating of two or more kinds And a lower layer of the fcc structure, and Ti _{x 1} Al _{y 1} N (where x 1 and y 1 are numbers satisfying atomic ratios of x 1 = 0.45 to 0.05, y 1 = 0.55 to 0.95, and x 1 + y 1 = 1). Forming a hard film having a titanium aluminum nitride film having an fcc structure having the following composition, and having a bonding layer between the lower layer and the titanium aluminum nitride film, and the bonding layer is made of Ti _{x 2} Al _{y 2} N ( Provided that x2 and y2 are numbers satisfying the atomic ratio x2 = 0.55 to 0.80, y2 = 0.45 to 0.20, and x2 + y2 = 1.) and the fcc structure, and the bond to the lower layer More than 30% of the plaid is continuous at the interface with the layer, At the interface between the bonding layer and the titanium aluminum nitride film, 30% or more of the lattice is continuous.

  FIG. 1 shows the layer structure of the hard film. A lower layer 22, a bonding layer (not visible in FIG. 1), and a titanium aluminum nitride film 23 are sequentially formed on the WC-based cemented carbide substrate 21.

(A) Substrate The substrate needs to be a high heat resistant material to which a chemical vapor deposition method can be applied. For example, WC base cemented carbide, cermet, high speed steel, tool steel or boron nitride mainly composed of cubic boron nitride A sintered body (cBN), ceramics such as sialon, etc. may be mentioned. From the viewpoints of strength, hardness, wear resistance, toughness and thermal stability, WC-based cemented carbides, cermets or ceramics are preferred. For example, in the case of WC base cemented carbide, it is possible to form the titanium aluminum nitride film of the present invention on the as-sintered unmachined surface, but to increase the dimensional accuracy of the tool It is preferable to form on the processing surface).

(B) Lower Layer A film of Ti (CN), TiN or TiZr (CN) having a columnar crystal structure is excellent in adhesion to a bonding layer made of a Ti-rich titanium aluminum nitride film. A film of Ti (CN), TiN or TiZr (CN) having a columnar crystal structure is excellent in wear resistance, but easily oxidized at high temperatures and low in heat resistance. Therefore, by forming an Al-rich titanium aluminum nitride film directly on the Ti (CN), TiN or TiZr (CN) film having a columnar crystal structure via the bonding layer, the heat resistance is excellent and the tool life is excellent. A long hard-coated tool is obtained. In addition, since each layer is not necessarily completely flat, even when simply called "layer thickness", it means "average layer thickness". The composition of the lower layer was measured by an electron probe microanalyzer (EPMA, JXA-8500F manufactured by JEOL Ltd.) 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.

  The temperature at which a film of Ti (CN), TiN or TiZrCN having a columnar crystal structure is formed by a chemical vapor deposition method is very close to the formation temperature of the bonding layer and titanium aluminum nitride film according to the present invention. Industrial productivity is high.

(C) Bonding layer
(1) Composition The bonding layer formed directly on the lower layer by chemical vapor deposition is composed of Ti-rich nitride containing Ti and Al as essential components. The bonding layer has a composition represented by Ti _{x 2} Al _{y 2} N (where x 2 and y 2 are numbers satisfying atomic ratios of x 2 = 0.55 to 0.80, y 2 = 0.45 to 0.20, and x 2 + y 2 = 1). If the composition range is out of the above composition range, since the checkered pattern is not continuous at the interface between the lower layer and the bonding layer and / or at the interface between the bonding layer and the titanium aluminum nitride film, the peel resistance is lowered. 0.58-0.75 are preferable and, as for x2, 0.60-0.70 are more preferable. 0.4-0.25 are preferable and 0.38-0.30 are more preferable. 30 atomic% or less of N may be substituted by C or B. The composition of the bonding layer was measured by an energy dispersive X-ray spectrometer as described later.

(2) Layer thickness The layer thickness of the bonding layer is preferably 2 to 50 nm. If the layer thickness is less than 2 nm, the bonding layer is too thin and the effect of the bonding layer can not be obtained sufficiently. On the other hand, if the layer thickness is more than 50 nm, the bonding layer is too thick, so the crystal orientation is dispersed, and the continuity of the lattice is obtained at the interface between the lower layer and the bonding layer and at the interface between the bonding layer and the titanium aluminum nitride film. And peel resistance is insufficient. The more preferred layer thickness of the bonding layer is 4 to 40 nm.

(3) Structure From FIGS. 2 and 3, it can be seen that 30% or more of the lattice is continuous at the interface between the lower layer 22 and the bonding layer 25 and at the interface between the bonding layer 25 and the titanium aluminum nitride film 23 It can be seen from FIG. 4 that the crystal structure of the bonding layer is a single fcc structure. In order for 30% or more of the lattice to be continuous at the two interfaces, the bonding layer preferably has an fcc structure as a main structure, and more preferably an fcc single structure. When a large amount of hcp structure is contained in the bonding layer, the continuity of the lattice from the lower layer to the titanium aluminum nitride film is lowered, and the peel resistance is lowered.

(D) Plaid Plaid is a striped pattern which is observed when a polycrystal is observed at a high magnification by TEM. The lattice images of both crystals are simultaneously observed only when the crystal orientations of adjacent layers are both parallel to the TEM incident beam. The continuity of the lower layer, the bonding layer and the lattice of the titanium aluminum nitride film means that these layers are in an epitaxial relationship. In the present invention, when 30% or more of the plaid is continuous at the above two interfaces, it is said that the plaid is continuous. In the hard-coated tool according to the present invention, the higher the ratio of continuous plaids, the higher the peel resistance tends to be. Therefore, in order to have high tool performance, the ratio in which the lattice pattern is continuous needs to be 30% or more, preferably 50% or more, and more preferably 70% or more.

(E) Titanium nitride aluminum film
(1) Composition As a direct upper layer of the bonding layer, it is represented by Tix1Aly1N (however, x1 and y1 are numbers satisfying x1 = 0.25 to 0.05, y1 = 0.55 to 0.95, and x1 + y1 = 1 in atomic ratio, respectively). An Al-rich titanium aluminum nitride film is formed. The titanium aluminum nitride film is made of nitride containing Ti and Al as essential elements. If the composition range is out of the above range, the checkered pattern is not continuous at the interface between the bonding layer and the titanium aluminum nitride film, and the peel resistance is reduced.
0.4-0.1 are preferable and, as for x1, 0.35-0.15 are more preferable. 0.6-0.9 are preferable and 0.65-0.85 are more preferable. The titanium aluminum nitride film may contain Cl as an unavoidable impurity, but the Cl content is preferably 1.5 atomic% or less, and more preferably 0.8 atomic% or less. The composition of the titanium aluminum nitride film was measured by EPMA similarly to the lower layer.

(2) Film Thickness In order to have excellent heat resistance and peel resistance, the film thickness of the titanium aluminum nitride film is preferably 1 to 15 μm, and more preferably 2 to 12 μm. If the film thickness is less than 1 μm, the effect of the film can not be sufficiently obtained. When the film thickness exceeds 15 μm, the film becomes too thick, and a crack is generated inside the film to make it easy to peel off. The film thickness of the titanium aluminum nitride film can be appropriately controlled by the film forming time.

(F) Upper layer of titanium aluminum nitride film Although not limited thereto, at least one element selected from the group consisting of Ti, Al, Cr, B and Zr on titanium aluminum nitride film, C, N and O A single layer or multilayer hard film essentially comprising at least one element selected from the group consisting of The top layer, for example TiC, CrC, SiC, VC, ZrC, TiN, AlN, CrN, Si 3 N 4, VN, ZrN, Ti (CN), (TiSi) N, (TiB) N, TiZrN, TiAl (CN And Ti / Si (CN), TiCr (CN), TiZr (CN), Ti (CNO), TiAl (CNO), Ti (CO), Ti (CO), and TiB ₂ etc.

[2] Chemical Vapor Deposition Apparatus The hard-coated tool of the present invention can be formed by a chemical vapor deposition method using a thermal chemical vapor deposition apparatus or a plasma enhanced chemical vapor deposition apparatus (CVD furnace). As shown in FIG. 5, the CVD furnace 1 includes a chamber 2, a heater 3 provided in the wall of the chamber 2, a plurality of shelves (jigs) 4, 4 rotating in the chamber 2, a shelf 4, 4, the first and second pipes 11 and 12 vertically penetrating the central opening 4a of the shelves 4 and 4, and the plurality of nozzles 11a and 12a provided in each of the pipes 11 and 12 Equipped with The shelves 4 4 on which a large number of insert bases 20 are mounted rotate in the chamber 2. The first and second pipes 11, 12 are integrally fixed at both ends by holding members (not shown) to form a pipe assembly, and penetrate the bottom of the chamber 2 so as to be able to rotate integrally. , It is rotatably connected to external piping (not shown). At the bottom of the chamber 2, there is a pipe 13 for discharging the carrier gas and the unreacted gas.

[3] Manufacturing Method The hard-coated tool according to the present invention will be described in detail below taking the case of using thermal chemical vapor deposition as an example, but the present invention is of course not limited thereto and can be applied to other chemical vapor depositions. .

(A) Formation of lower layer
(1) Carboxy titanium nitride film After flowing H ₂ gas, N ₂ gas and / or Ar gas into the CVD furnace in which the substrate is set and raising the temperature to the film forming temperature, TiCl ₄ gas, N ₂ gas, CH ₃ CN A raw material gas composed of gas (or CH ₃ CN gas and C ₂ H ₆ gas) and H ₂ gas is flowed into a CVD furnace to form a lower titanium carbonitride film.

(2) Titanium nitride film After flowing H ₂ gas, N ₂ gas and / or Ar gas into the CVD furnace in which the base is set and raising the temperature to the film forming temperature, TiCl ₄ gas, N ₂ gas and H ₂ gas The source gas comprising the above is flowed into a CVD furnace to form a titanium nitride film as a lower layer.

(3) Titanium zirconium carbonitride film The H ₂ gas, N ₂ gas and / or Ar gas is flowed into the CVD furnace in which the base is set, and the temperature is raised to the film forming temperature, then TiCl ₄ gas, ZrCl ₄ gas, N ₂ A raw material gas composed of gas, CH ₃ CN gas (or CH ₃ CN gas and C ₂ H ₆ gas), and H ₂ gas is flowed into a CVD furnace to form a titanium zirconium carbonitride film of the lower layer.

(B) Formation of Bonding Layer The bonding layer is formed by supplying the second source gas after supplying the first source gas to the CVD furnace. The first source gas, TiCl ₄ gas, AlCl ₃ gas, a mixed gas A ₁ consisting of N ₂ gas and H ₂ gas, consists of _a Metropolitan mixed gas consisting of N ₂ gas and H ₂ gas B, the second material gas is composed of TiCl ₄ gas, and AlCl ₃ gas, a mixed gas a ₂ consisting of N ₂ gas and H ₂ gas, NH ₃ gas, consisting of N ₂ gas and H ₂ gas mixed gas B ₂ Prefecture. In the first and second source gases, part or all of the carrier gas H ₂ gas may be replaced with Ar gas.

(1) First source gas
(a) Mixed gas A ₁
The composition of the gas mixture A _1, TiCl ₄ gas in the first raw material gas, AlCl ₃ gas, as 100% by volume total of N ₂ gas and H ₂ gas, 0.18 to 0.77% by volume of TiCl ₄ gas, 0.06 Preferably, it consists of 0.35% by volume of AlCl ₃ gas, 4 to 15% by volume of N ₂ gas, and the balance H ₂ gas.

If the TiCl ₄ gas is less than 0.18% by volume, the amount of Al in the mixed gas A ₁ is too large, and the hcp structure is included, so that the portion in which the lattice does not continue increases. On the other hand, when the TiCl ₄ gas exceeds 0.77% by volume, the Ti content in the bonding layer becomes excessive and the oxidation resistance is poor. The lower limit of the content of TiCl ₄ gas is more preferably 0.2% by volume, and most preferably 0.25% by volume. The upper limit of the content of TiCl ₄ gas is more preferably 0.45% by volume, and most preferably 0.38% by volume.

If the content of AlCl ₃ gas is less than 0.06% by volume, the Ti content in the bonding layer is too high, and the oxidation resistance is poor. On the other hand, when the AlCl ₃ gas exceeds 0.35% by volume, the amount of Al in the bonding layer is too large, hcp structure is generated, and the lattice does not continue to the lower layer. The lower limit of the content of AlCl ₃ gas is more preferably 0.07% by volume, and most preferably 0.08% by volume. The upper limit of the content of AlCl ₃ gas is more preferably 0.3% by volume, and most preferably 0.2% by volume.

When the N ₂ gas content is less than 4% by volume or more than 15% by volume, the film thickness distribution of the bonding layer formed on the substrate is deteriorated. N ₂ gas is more preferably 4.8 to 14% by volume.

(b) Mixed gas B ₁
The composition of the mixed gas B ₁ is 4 to 15% by volume of N ₂ gas with the balance being 100% by volume of the total of TiCl ₄ gas, AlCl ₃ gas, N ₂ gas and H ₂ gas in the first source gas It is preferably made of H ₂ gas. When the N ₂ gas content is less than 4% by volume or more than 15% by volume, the film thickness distribution of the bonding layer formed on the substrate is deteriorated. N ₂ gas is more preferably 4.8 to 14% by volume.

(2) a second source gas second source gas, TiCl ₄ gas, AlCl ₃ gas, a mixed gas A ₂ consisting of N ₂ gas and H ₂ gas from the NH ₃ gas, N ₂ gas and H ₂ gas a mixed gas B ₂ Metropolitan made. The second source gas is different from the first source gas in that the mixed gas B ₂ contains an NH ₃ gas.

(a) Mixed gas A ₂
Composition of the mixed gas A ₂ is, TiCl ₄ gas in the second source gas, AlCl ₃ gas, NH ₃ gas, a total of N ₂ gas and H ₂ gas as 100 volume%, TiCl ₄ of 0.18 to 0.77 vol% Preferably, the gas comprises 0.06 to 0.35% by volume of AlCl ₃ , 4 to 15% by volume of N ₂ gas, and the balance H ₂ gas.

If the TiCl ₄ gas is less than 0.18% by volume, the amount of Al in the mixed gas A ₁ is too large, and the hcp structure is included, so that the portion in which the lattice does not continue increases. On the other hand, when the TiCl ₄ gas exceeds 0.77% by volume, the Ti content in the bonding layer becomes excessive and the oxidation resistance is poor. The lower limit of the content of TiCl ₄ gas is more preferably 0.2% by volume, and most preferably 0.25% by volume. The upper limit of the content of TiCl ₄ gas is more preferably 0.45% by volume, and most preferably 0.38% by volume.

If the content of AlCl ₃ gas is less than 0.06% by volume, the Ti content in the bonding layer is too high, and the oxidation resistance is poor. On the other hand, when the AlCl ₃ gas exceeds 0.35% by volume, the amount of Al in the bonding layer is too large, hcp structure is generated, and the lattice does not continue. The lower limit of the content of AlCl ₃ gas is more preferably 0.07% by volume, and most preferably 0.08% by volume. The upper limit of the content of AlCl ₃ gas is more preferably 0.3% by volume, and most preferably 0.2% by volume.

When the N ₂ gas content is less than 4% by volume or more than 15% by volume, the film thickness distribution of the bonding layer formed on the substrate is deteriorated. N ₂ gas is more preferably 4.8 to 14% by volume.

(b) Mixed gas B ₂
The composition of the mixed gas B _2, TiCl ₄ gas in the second source gas, AlCl ₃ gas, NH ₃ gas, as a total of 100% by volume of N ₂ gas and H ₂ gas, NH ₃ from 0.85 to 1.5 vol% Preferably, the gas comprises 4 to 15% by volume of N ₂ gas and the balance H ₂ gas.

If the NH ₃ gas content is less than 0.85% by volume, the reaction rate is too slow. On the other hand, when the NH ₃ gas is more than 1.5% by volume, the checkered pattern between the lower layer and the bonding layer is not continuous. The lower limit of the content of NH ₃ gas is more preferably 0.9% by volume, and most preferably 1% by volume. The upper limit of the content of NH ₃ gas is more preferably 1.4% by volume, and most preferably 1.2% by volume.

When the N ₂ gas content is less than 4% by volume or more than 15% by volume, the film thickness distribution of the bonding layer formed on the substrate is deteriorated. N ₂ gas is more preferably 4.8 to 14% by volume.

(C) A condition for obtaining a continuous lattice at the interface between the lower layer and the bonding layer When nuclei of the bonding layer are rapidly generated at the initial stage of film formation of the bonding layer, crystal orientations are dispersed, and the lattice between the lower layer and the bonding layer Is not continuous. In the present invention, since the first raw material gas containing no highly reactive NH ₃ gas is used after the formation of the lower layer, the reaction rate of TiCl ₄ gas and AlCl ₃ gas with N ₂ gas is very slow, and the lower layer The nucleus of the bonding layer is generated slowly in the same direction as the crystal orientation of the (TiCN layer). When the nuclei of the bonding layer are rapidly generated, the nuclei grow in various directions, so that the peeling resistance with the titanium aluminum nitride film formed directly thereon is reduced.

It is preferable to control the volume ratio of TiCl ₄ gas to AlCl ₃ gas (TiCl ₄ / AlCl ₃ ) in the first raw material gas to 1.0 to 5.5, in order for the lattice to be continuous at the interface between the lower layer and the bonding layer. . If the TiCl ₄ / AlCl ₃ ratio is less than 1.0, if the Ti content of the bonding layer is too low, the hcp structure is partially formed, and the lower layer and the lattice do not continue. On the other hand, when the TiCl ₄ / AlCl ₃ ratio is more than 5.5, the Al content of the bonding layer is too small, and the adhesion between the lower layer and the bonding layer is insufficient. The TiCl ₄ / AlCl ₃ ratio is more preferably 1.5 to 4.0.

(D) Conditions for obtaining a continuous lattice at the interface between the bonding layer and the titanium aluminum nitride film In order to obtain a continuous lattice at the interface between the bonding layer and the titanium aluminum nitride film, see FIG. 6 of either using an integral pipe assembly, the distance H ₁ between the rotation axis O and spout of the first nozzle 11a of the rotary shaft O and spout of the second nozzle 12a (c) distance longer than H _2, it is preferable that the H1 / H2 = 1.5~3.

(E) a third source gas for forming the formed titanium aluminum nitride film of titanium aluminum nitride coating, a TiCl ₄ gas, AlCl ₃ gas, N ₂ gas mixture A ₃ consisting of gas and H ₂ gas, NH ₃ gas, a mixed gas B ₃ Metropolitan consisting N ₂ gas and H ₂ gas. In the third source gas, part or all of the carrier gas H ₂ gas may be replaced with Ar gas.

(1) Mixed gas A ₃
Composition of the mixed gas A ₃ is, TiCl ₄ gas of the third source gas, AlCl ₃ gas, NH ₃ gas, a total of N ₂ gas and H ₂ gas as 100 volume%, TiCl ₄ of 0.02 to 0.31 vol% Preferably, the gas consists of 0.15 to 0.8% by volume of AlCl ₃ gas, 4.9 to 21.8% by volume of N ₂ gas, and the balance H ₂ gas. The lower limit of the content of TiCl ₄ gas is more preferably 0.08% by volume, and the upper limit is more preferably 0.25% by volume. The lower limit of the content of AlCl ₃ gas is more preferably 0.2% by volume, and the upper limit is more preferably 0.6% by volume. The lower limit of the content of N ₂ gas is more preferably 6% by volume, and the upper limit is more preferably 10% by volume.

(2) Mixed gas B ₃
Composition of the mixed gas B ₃ is, TiCl ₄ gas of the third source gas, AlCl ₃ gas, NH ₃ gas, a total of N ₂ gas and H ₂ gas as 100 vol%, NH ₃ of 0.7 to 1.9 vol% Preferably, the gas comprises 3 to 16.5% by volume of N ₂ gas and the balance H ₂ gas. If the NH ₃ gas content is less than 0.7% by volume, the reaction rate is too slow. On the other hand, when the NH ₃ gas is more than 1.9% by volume, the checkered pattern of the bonding layer and the titanium aluminum nitride film is not continuous. The lower limit of the content of NH ₃ gas is more preferably 0.8% by volume, and the upper limit is more preferably 1.3% by volume. The lower limit of the N ₂ gas content is more preferably 6% by volume, and the upper limit is more preferably 10% by volume.

(F) Method of introducing raw material gas In order to form a bonding layer and titanium aluminum nitride while controlling the reaction rate, mixed gas A (A ₁ , A ₂ , A ₃ ) having high reactivity and mixed gas B (B) ₁ , B ₂ , B ₃ ) must be fed into the CVD furnace 1 in a noncontact state. Therefore, the mixed gas A is jetted from the first nozzle 11 a of the first pipe 11, and the mixed gas B is jetted from the second nozzle 12 a of the second pipe 12.

  As illustrated in FIGS. 5 and 6 (a) to 6 (c), the first and second mixed gases A and B are injected so as not to obstruct the flow of the mixed gases A and B ejected from the respective nozzles. It is necessary to dispose one of the second nozzles at the center side and the other at the outer peripheral side, and separately blow out the mixed gas A and the mixed gas B from the first and second nozzles.

  In order to obtain a continuous plaid microstructure, the nozzles 11a and 12a for introducing the mixed gases A and B preferably rotate at a speed of 2 to 4 revolutions / minute. The rotational direction of the first and second nozzles 11a and 12a is not limited.

6 (a) to 6 (c) show preferred examples of the nozzle structure for spouting the mixed gases A and B. FIG. With respect to the rotation axis O of the pipe assembly 30, the first nozzle 11a is located on the outer peripheral side, and the second nozzle 12a is located on the central side. In order to form a continuous checkered microstructure, the distance between the nozzle of the nozzle that jets the mixed gas B and the coating is shorter than the distance between the nozzle of the nozzle that jets the mixed gas A and the coating Is preferred. The TiCl ₄ gas and the AlCl ₃ gas in the mixed gas A are very reactive with the NH ₃ gas in the mixed gas B, and react rapidly when introduced into the CVD furnace. If the reaction rate is high, the reaction is likely to occur before reaching the coating. Therefore, as shown in FIG. 9, when the nozzle openings for spouting the mixed gases A and B are equidistant from the rotation axis, a reaction occurs before the mixed gas A reaches the coating, and the continuous checkered microstructure I can not get it. On the other hand, when the distance between the spout of the mixed gas B nozzle and the covering is shorter than the distance between the spout of the mixed gas A nozzle and the covering, the reaction until the mixed gas A reaches the covering Is reduced to obtain a continuous checkered microstructure. Conversely, if the distance between the jet of the mixed gas A nozzle and the coating is shorter than the distance between the jet of the mixed gas B nozzle and the coating, the TiCl ₄ gas and the AlCl ₃ gas are uniformly distributed in the chemical vapor deposition atmosphere. And it is difficult to form a uniform titanium aluminum nitride hard coating.

In order to obtain a continuous checkered microstructure, it is preferable that the first nozzle 11a on the outer peripheral side ejects the mixed gas A and the second nozzle 12a on the inner peripheral side ejects the mixed gas B. In this case, the ratio (H ₁ / H ₂ ) between the distance H ₁ between the jet nozzle of the first nozzle 11 a and the rotation axis O and the distance H ₂ between the jet nozzle of the second nozzle 12 a and the rotation axis O is 1.5 It is preferable to be in the range of -3.

(1) First Pipe Assembly FIG. 6 (a) shows an example of a first pipe assembly 30 for introducing the mixed gas A and the mixed gas B into the CVD furnace 1 in a non-contact state. The pipe assembly 30 comprises two first pipes 11 and 11 and one second pipe 12, and both end portions of the first and second pipes 11 and 12 are holding members (not shown). Fixed integrally.

The first pipe 11 has a radius R ₁ and the second pipe 12 has a radius R ₂ . The central axis O ₁ of the first pipe 11 is located on the circumference C _{1 of} the first diameter D ₁ centered on the rotation axis O. Thus, the two first pipes 11, 11 are equidistant from the rotation axis O. The central angle θ with respect to the rotation axis O of the center axis O _1, O ₁ of the first pipe 11, 11 preferably is 90 to 180 °. The center axis O ₂ of the second pipe 12 is coincident with the rotation axis O, the outer circumference of the second pipe 12, the second diameter D ₂ around the rotation axis O of the (= 2R ₂₎ It is consistent with the circumference C _2.

The nozzles (first nozzles) 11a, 11a of the first pipes 11, 11 face outward and in the opposite direction (direction of 180 °). In the example of illustration, although each 1st pipe 11 has nozzle (1st nozzle) 11a of 1 row of vertical directions, it is not limited to this, 1st nozzle 11a may be multiple rows. Further, the second pipe 12 has two longitudinal rows of nozzles (second nozzles) 12a and 12a disposed in the diametrical direction (the direction of 180 °). Of course, the second nozzles 12a are not limited to two rows, but may be one row. Since the first diameter D ₁ is larger than the second diameter D ₂ [D ₁ 2 2 (R ₁ + R ₂ )], when the pipe assembly 30 rotates around the rotation axis O, the first nozzle 11 a, 11a is located on the outer peripheral side, and the second nozzles 12a and 12a are located on the inner peripheral side.

If the second pipe 12 has one row of the second nozzle 12a and the central axes O ₁ and O _{1 of} the first pipes 11 and 11 are less than 180 °, the second nozzle 12a is the first It is preferable to face in the direction away from the nozzles 11a and 11a (opposite the central angle θ). In this case, it is preferable that the jetting direction of the first nozzle 11a and the jetting direction of the second nozzle 12a are orthogonal to each other.

The central axes O ₁ , O _{1 of} the first pipes 11, 11 are in line with the central axis O ₂ of the second pipe 12, and the second pipes 12 have two rows of second nozzles 12 a, 12 a In the case of having, the first nozzles 11a and 11a face in the direction opposite to each other (the direction of 180.degree.), And the second nozzle 12a faces in the direction perpendicular to the first nozzles 11a and 11a in the direction opposite to each other ( 90 ° central angle) is preferred.

(2) Second Pipe Assembly FIG. 6 (b) shows an example of a second pipe assembly 40 for introducing the mixed gas A and the mixed gas B into the CVD furnace 1 in a non-contact state. The pipe assembly 40 comprises a first pipe 11 and a second pipe 12, and both ends of the first and second pipes 11 and 12 are integrally formed by holding members (not shown). It is fixed. The first pipe 11 has one row (first nozzle) 11a, and the second pipe 12 also has one longitudinal row (second nozzle) 12a.

Central axis O ₂ of the second pipe 12 is coincident with the rotation axis O of the pipe assembly 40, the first pipe 11 is disposed at a position close to the second pipe 12. The first pipe 11 has a radius R ₁ and the second pipe 12 has a radius R ₂ . The central axis O ₁ of the first pipe 11 is located on the circumference C _{1 of} the first diameter D ₁ centered on the rotational axis O, and the central axis O ₂ of the second pipe 12 is with the rotational axis O They coincide, and their outer circumference coincides with the circumference C _{2 of} the second diameter D ₂ (= 2R ₂ ) about the rotation axis O. Since the first diameter D ₁ is larger than the second diameter D ₂ [D ₁ 2 2 (R ₁ + R ₂ )], when the pipe assembly 40 is rotated about the rotation axis O, the first nozzle 11 a has an outer periphery Located on the side, the second nozzle 12a is located on the inner circumferential side.

  In the illustrated example, the nozzle (first nozzle) 11a of the first pipe 11 and the second nozzle 12a of the second pipe 12 face in the direction opposite to each other (in the direction of 180 °). Instead, the central angle between the first nozzle 11a and the second nozzle 12a may be in the range of 90 to 180 degrees.

(3) Third Pipe Assembly FIG. 6 (c) shows an example of a third pipe assembly 50 for introducing the mixed gas A and the mixed gas B into the CVD furnace 1 in a noncontacting manner. The pipe assembly 50 comprises four first pipes 11, 11, 11, 11 and one second pipe 12, and both ends of the first and second pipes 11, 11, 11, 12, 12 The portion is integrally fixed by a holding member (not shown). Each first pipe 11 has one longitudinal row (first nozzle) 11a, and the second pipe 12 has two pairs of longitudinal rows of nozzles arranged in orthogonal diametrical directions (180 °) Second nozzle) 12a, 12a, 12a, 12a. The nozzles (first nozzles) 11a, 11a, 11a, 11a of all the first pipes 11, 11, 11, 11 face outward.

The first pipe 11 has a radius R ₁ and the second pipe 12 has a radius R ₂ . The central axis O ₁ of the first pipe 11 is located on the circumference C _{1 of} the first diameter D ₁ centered on the rotation axis O. Thus, the four first pipes 11, 11, 11, 11 are equidistant from the rotation axis O. The center axis O ₂ of the second pipe 12 is coincident with the rotation axis O, the circumference and the circumference C ₂ of the second diameter D ₂ around the rotation axis O (= 2R ₂₎ one I do. Since the first diameter D ₁ is larger than the second diameter D ₂ [D ₁ 2 2 (R ₁ + R ₂ )], when the pipe assembly 50 rotates about the rotation axis O, the first nozzles 11 a and 11 a , 11a and 11a are located on the outer peripheral side, and the second nozzles 12a, 12a, 12a and 12a are located on the inner peripheral side. In the illustrated example, the central angle θ with respect to the rotational axis O of the central axes O ₁ and O ₁ of the adjacent first pipes 11 and 11 is 90 °, but is not limited thereto, and may be 60 to 120 °. .

(G) Deposition conditions
(1) Film forming temperature The film forming temperature of the bonding layer and the titanium aluminum nitride film is preferably 750 to 830 ° C., and more preferably 780 to 820 ° C. When the film formation temperature is less than 750 ° C., the titanium aluminum nitride film having the hcp structure is large and the peel resistance is poor. On the other hand, if the film formation temperature exceeds 830 ° C., the reaction is promoted too much and layer thickness control is difficult.

(2) Reaction pressure The reaction pressure of the bonding layer and the titanium aluminum nitride film is preferably 3 to 6 kPa. If the reaction pressure is outside the above range, the lattice does not continue at the interface between the lower layer and the bonding layer.

(3) Deposition time
When the rotational speed of the nozzle is set to 2 to 4 rpm at a temperature of 750 ° C. to 850 ° C., the film forming time of the bonding layer is preferably 100 to 300 seconds in the case of the first source gas, and 150 to 210 seconds is more preferable. preferable. In the case of the second source gas, 15 to 180 seconds are preferable, and 30 to 60 seconds are more preferable.

(H) Post-process
(1) Formation of Upper Layer Although not particularly limited, the upper layer of the titanium aluminum nitride film can be formed by a known chemical vapor deposition method. The film forming temperature may be 700 to 1050.degree. Examples of source gases used to form the upper layer are as follows.
1. TiC coating TiCl ₄ gas, CH ₄ gas and H ₂ gas.
2. CrC coating CrCl ₃ gas, CH ₄ gas and H ₂ gas.
3. SiC coating SiCl ₄ gas, CH ₄ gas and H ₂ gas.
4. VC film VCl gas, CH ₄ gas and H ₂ gas.
5. ZrC film ZrCl ₄ gas, CH ₄ gas and H gas.
6. TiN film TiCl ₄ gas, N ₂ gas and H ₂ gas.
7. AlN film AlCl ₃ gas, NH ₄ gas and H ₂ gas.
8. CrN coating CrCl ₃ gas, NH ₄ gas and H ₂ gas.
9. Si ₃ N ₄ coating SiCl ₄ gas, NH ₄ gas and H ₂ gas.
10. VN coating VCl ₃ gas, NH ₄ gas and H ₂ gas.
11. ZrN film ZrCl ₄ gas, N ₂ gas and H ₂ gas.
12. Ti (CN) film TiCl ₄ gas, CH ₄ gas, N ₂ gas and H ₂ gas, or TiCl ₄ gas, CH ₃ CN gas, N ₂ gas and H ₂ gas.
13. (TiSi) N coating TiCl ₄ gas, SiCl ₄ gas, N ₂ gas and NH ₃ gas.
14. (TiB) N film TiCl ₄ gas, N ₂ gas and BCl ₃ gas.
15. TiZr (CN) film TiCl ₄ gas, ZrCl ₄ gas, N ₂ gas, CH ₄ gas and H ₂ gas, or TiCl ₄ gas, ZrCl ₄ gas, N ₂ gas, CH ₃ CN gas and H ₂ gas.
16. TiAl (CN) film TiCl ₄ gas, AlCl ₃ gas, N ₂ gas, CH ₄ gas, NH ₃ gas and H ₂ gas, or TiCl ₄ gas, AlCl ₃ gas, N ₂ gas, CH ₃ CN gas and H ₂ gas.
17. TiSi (CN) film TiCl ₄ gas, SiCl ₄ gas, N ₂ gas, N ₂ gas, CH ₄ gas, NH ₃ gas and H ₂ gas, or TiCl ₄ gas, SiCl ₄ gas, N ₂ gas, CH ₃ CN gas and H 2 ₂ gas.
18. TiCr (CN) film TiCl ₄ gas, CrCl ₃ gas, N ₂ gas, CH ₄ gas, NH ₃ gas and H ₂ gas, or TiCl ₄ gas, CrCl ₃ gas, N ₂ gas, CH ₃ CN gas and H ₂ gas.
19. TiV (CN) film TiCl ₄ gas, VCl ₃ gas, N ₂ gas, CH ₄ gas, NH ₃ gas and H ₂ gas, or TiCl ₄ gas, VCl ₃ gas, N ₂ gas, CH ₃ CN gas and H ₂ gas.
20. TiZr (CN) coating TiCl ₄ gas, ZrCl ₃ gas, N ₂ gas, N ₂ gas, CH ₄ gas, NH ₃ gas and H ₂ gas, or TiCl ₄ gas, ZrCl ₄ gas, N ₂ gas, CH ₃ CN gas and H ₂ gas.
21. Ti (CNO) film TiCl ₄ gas, N ₂ gas, CH ₄ gas, CO gas and H ₂ gas, or TiCl ₄ gas, N ₂ gas, CH ₃ CN gas, CO gas and H ₂ gas.
22. TiAl (CNO) film TiCl ₄ gas, AlCl ₃ gas, N ₂ gas, CH ₄ gas, CO gas and H ₂ gas, or TiCl ₄ gas, AlCl ₃ gas, N ₂ gas, CH ₃ CN gas, CO gas And H ₂ gas.
23. Ti (CO) coating TiCl ₄ gas, N ₂ gas, CH ₄ gas, CO gas, CO ₂ gas and H ₂ gas.
24. TiB ₂ film TiCl ₄ gas, BCl ₃ gas, H ₂ gas.

(2) Cutting Edge Treatment after Coating with Hard Film The titanium aluminum nitride film formed on the substrate is smoothed by treatment with a brush, buff or blast, and becomes a surface state excellent in chipping resistance. In particular, when powder of ceramics such as alumina, zirconia and silica is used as a shot material and the cutting edge of the hard film is treated by a wet or dry blast method, the surface of the hard film is smoothed and the tensile residual stress of the hard film is lowered. And the chipping resistance is improved.

  The invention will be explained in more detail by means of the following examples, but of course the invention is not limited thereto. In the following examples and comparative examples, the flow rate (L / min) is the flow rate under the conditions of 1 atm and 25 ° C. Moreover, the thickness of each layer is an average value.

Example 1
(1) Formation of Hard Film A WC-based cemented carbide (composed of 11.5% by mass of Co, 2.0% by mass of TaC, 0.7% by mass of CrC, balance WC and unavoidable impurities) schematically shown in FIG. Insert base for milling (SEE42TN-C9) 8 and WC base cemented carbide (7% by mass Co, 0.6% by mass CrC, 2.2% by mass ZrC, 3.3% by mass TaC, 0.2% by mass NbC, balance WC and inevitable impurities.) made of a property-evaluation insert base (SNMN120408), set in CVD furnace 1 shown in FIG. 5, increasing the temperature of the CVD furnace 1 to 850 ° C. while introducing H ₂ gas I did. Then, at 700 ° C. and 8 kPa, 6700 mL of a raw material gas consisting of 83.1% by volume of H ₂ gas, 15.0% by volume of N ₂ gas, 1.5% by volume of TiCl ₄ gas, and 0.4% by volume of CH ₃ CN gas It flowed into the CVD furnace 1 with the flow rate of the minute. Thus, a titanium carbonitride Ti (CN) layer having a columnar crystal structure and a composition represented by Ti _0.61 C _0.39 N (atomic ratio) was formed on each substrate by chemical vapor deposition.

(2) Formation of bonding layer
(a) Introduction of the first source gas
Using the pipe assembly 30 shown in FIG. 6 (a) rotating at a speed of 2 rpm while lowering the temperature in the CVD furnace 1 to 800 ° C. and reducing the pressure to 4 kPa, the mixed gas A ₁ and the mixed gas A ₁ and first material gas comprising a mixed gas B ₁ were introduced. Specifically, 0.31% by volume of TiCl ₄ gas, 0.15% by volume of AlCl ₃ gas, 53.19% by volume of H ₂ gas, and 7.60% by volume of the first nozzles 11a and 11a of the first pipes 11, 11 Mixed gas A ₁ containing N ₂ gas is introduced, and mixed gas B containing 31.15% by volume of H ₂ gas and 7.60% by volume of N ₂ gas from the second nozzles 12 a of the second pipe 12 12. ₁ was introduced. The total flow rate of the mixed gas A ₁ and B ₁ was 65.80 L / min. The film formation time was 180 seconds.

(b) Introduction of second source gas Subsequently, while maintaining the temperature and pressure in the CVD furnace 1 at 800 ° C. and 4 kPa, the pipe assembly 30 shown in FIG. The second raw material gas composed of the mixed gas A ₂ and the mixed gas B ₂ was introduced into the CVD furnace 1 by using. Specifically, 0.31% by volume of TiCl ₄ gas, 0.15% by volume of AlCl ₃ gas, 52.59% by volume of H ₂ gas, and 7.51% by volume of the first nozzles 11a and 11a of the first pipes 11, 11 introducing a mixed gas a ₂ consisting of N ₂ gas, the second nozzle 12a of the second pipe 12, 12, 30.80% by volume of H ₂ gas from 12a, the 7.51% by volume of N ₂ gas, and 1.13 vol% and introducing a mixed gas B ₂ consisting of NH _3. The total flow rate of the mixed gas A ₂ and B ₂ was 66.55 L / min. The film formation time was 30 seconds. Thus, a 5 nm-thick bonding layer having a composition represented by Ti _0.65 Al _0.35 N (atomic ratio) was formed on the titanium carbonitride layer by chemical vapor deposition.

(3) Formation of titanium aluminum nitride film After formation of the bonding layer, the pipe assembly shown in FIG. 6 (a) rotates at a speed of 2 rpm while maintaining the temperature and pressure in the CVD furnace 1 at 800 ° C. and 4 kPa. The third source gas was introduced into the CVD furnace 1 using the body 30. Specifically, from the first nozzles 11a and 11a of the first pipes 11, 11, 0.15 volume% of TiCl ₄ gas, 0.45 volume% of AlCl ₃ gas, 52.51 volume% of H ₂ gas, and 7.50 volume% introducing a mixed gas a ₃ consisting of N ₂ gas, the second nozzle 12a of the second pipe 12, 12, 1.13% by volume of NH ₃ gas 12a, 30.76 vol% of H ₂ gas, and of 7.50 vol% and introducing a mixed gas B ₃ consisting of N ₂ gas. The total flow rate of the mixed gas A ₃ and B ₃ was 66.65 L / min. The film forming time is adjusted to obtain a hard coated tool in which a titanium aluminum nitride film having a thickness of 3 μm having a composition represented by Ti _0.31 Al _0.69 N (atomic ratio) is formed on the bonding layer by chemical vapor deposition. The

(4) Cross-sectional structure of the hard-coated tool The photograph of the cut surface of the rake surface of the obtained insert for evaluating the physical properties of the hard-coated tool (SNMN 120408) taken by SEM (S-4200 manufactured by Hitachi, Ltd.) : 10,000 times) is shown in FIG. In FIG. 1, 21 is a WC base cemented carbide substrate, 22 is a lower layer (a titanium carbonitride film having a columnar crystal structure), and 23 is a titanium aluminum nitride film. The bonding layer present between the titanium carbonitride coating 22 and the titanium aluminum nitride coating 23 is not visible due to the low magnification.

(5) Interfacial structure between the lower layer and the bonding layer, and the interface between the bonding layer and the titanium aluminum nitride film The boundary (interface) between the lower layer and the bonding layer, and the bonding layer and the titanium aluminum nitride film can be A photograph (magnification: 4000,000 times) taken using a TEM, JEM-2010F manufactured by Hitachi, Ltd., is shown in FIG. In FIG. 2, 22 is a lower layer (a titanium carbonitride film having a columnar crystal structure), 23 is a titanium aluminum nitride film, and 25 is a bonding layer. FIG. 3 (a) is a schematic view of FIG. In FIG. 3, the line L1 indicates the boundary between the lower layer (TiCN) 22 and the bonding layer 25, the line L2 indicates the boundary between the bonding layer 25 and the titanium aluminum nitride film 23, and many thin lines indicate crystal lattice stripes. From FIGS. 2 and 3 (a), 87% of the crystal lattice is continuous at the interface between the lower layer 22 and the bonding layer 25, and 70% of the crystal lattice is at the interface between the bonding layer 25 and the titanium aluminum nitride film 23. It was found to be continuous.

In FIG. 3 (c), which corresponds to FIG. 3 (b), when dividing the area S of the line L ₁ and the bonding layer 25 surrounded by the line L ₂ in the length L of the modified layer 25, coupled in one field of view The average thickness D ₁ of the layer 25 is determined. The average thicknesses D ₁ , D ₂ , D ₃ , D ₄ and D ₅ of the bonding layer 25 in five different fields of view are determined in the same manner, and the value obtained by arithmetically averaging them is taken as the average thickness Da of the bonding layer 25. The average thickness Da of the bonding layer 25 determined by this method was 5 nm.

  Using JEM-2010F, nanobeam diffraction was performed at about the center in the thickness direction of the bonding layer 25 of FIG. 3 under conditions of an acceleration voltage of 200 kV and a camera length of 50 cm. The nanobeam diffraction image (NAD) of the obtained coupling layer 25 is shown. It was found from FIG. 4 that the bonding layer 25 had an fcc structure.

(6) Measurement of composition of bonding layer
An insert for evaluating physical properties using an energy dispersive X-ray spectrometer (EDS, UTW type Si (Li) semiconductor detector manufactured by NORAN, beam diameter: about 1 nm) mounted on FE-TEM (JEM-2010F) The composition was analyzed at five arbitrary centers in the layer thickness direction center of the bonding layer in the hard coating cross section of SNMN 120408) and arithmetically averaged.

(7) Measurement of tool life The obtained milling insert 8 is attached to the tip of the indexable rotary tool (A45E-4160R) 9 shown in FIG. 8 with a wedge screw (not shown), and the following milling is performed The cutting is performed under the conditions, and the flank of the insert 8 sampled every unit time of the optical microscope with a magnification of 100 times is observed, and the total cutting length (m) when the maximum wear width of the flank becomes 0.25 mm or more Was determined as the tool life.

Cutting conditions Work material: Hardness 32 HRC SCM440
Machining method: Milling Insert shape: SEE42TN-C9
Cutting speed: 200 m / min Speed: 398 rpm
Feed per blade: 0.15 mm / tooth
Feeding speed: 477.6 mm / min Cutting amount in axial direction: 1.0 mm
Radial cut amount: 100 mm
Cutting method: wet cutting

Examples 2 to 15
A hard-coated tool (insert for milling) was produced and evaluated in the same manner as in Example 1 except that the film formation conditions for the bonding layer and the titanium aluminum nitride film were changed as shown in Tables 1 and 2.

Example 16
The same insert base for milling (SEE42TN-C9) and insert base for evaluation of physical properties (SNMN 120408) made of WC-based cemented carbide as in Example 1 are set in the CVD furnace 1, and the inside of the CVD furnace 1 is flushed with H ₂ gas. After raising the temperature to 900 ° C., the raw material gas consisting of 82.0% by volume of H ₂ gas, 18.5% by volume of N ₂ gas, and 1.5% by volume of TiCl ₄ gas at 900 ° C. and 12 kPa is 4500 ml / min It flowed into CVD furnace 1 with the flow volume of, and formed the titanium nitride film 3 micrometers in thickness by a chemical vapor deposition method. A hard-coated tool in which a bonding layer and a titanium aluminum nitride film were formed on the titanium nitride film obtained as in Example 1 was manufactured immediately after the obtained titanium nitride film, and the same evaluation as in Example 1 was performed.

Example 17
The same insert base for milling (SEE42TN-C9) made of WC base cemented carbide and the insert base for evaluating physical properties as in Example 1 are set in the CVD furnace 1, and the temperature in the CVD furnace 1 is 900 while flowing H ₂ gas. Raised to ° C. Then, at 900 ° C. and 8 kPa, 78.0% by volume of H ₂ gas, 18.5% by volume of N ₂ gas, 1.5% by volume of TiCl ₄ gas, 0.5% by volume of CH ₃ CN gas, and 1.5% by volume of ZrCl ₄ gas The raw material gas consisting of is flowed into the CVD furnace 1 at a flow rate of 7000 ml / min, and a 3 .mu.m-thick TiZr (CN) film having a composition represented by Ti _0.96 Zr _0.04 (CN) (atomic ratio) by chemical vapor deposition. It formed. A hard coating coated tool in which a bonding layer and a titanium aluminum nitride coating were formed on the titanium carbonitride zircon coating obtained as in Example 1 thereafter was manufactured, and the same evaluation as in Example 1 was performed.

Comparative Example 1
After forming a titanium carbonitride film in the same manner as in Example 1, the first and second nozzles 11a and 12a (central angle: 180 °, H ₁ = H ₂ shown in FIG. 9) are formed without forming a bonding layer. ) using a mixed gas a ₃ and B ₃ are shown in Table 3 is ejected from the first nozzle 11a and a second nozzle 12a, respectively, Ti _0.08 Al _0.92 by chemical vapor deposition at a deposition conditions shown in Table 4 N A titanium aluminum nitride film having a thickness of 3 μm having a composition represented by (atomic ratio) was formed. Evaluation similar to Example 1 was performed about the obtained hard-film coated tool (insert for milling).

  For Examples 1 to 17 and Comparative Example 1, the film forming conditions of the bonding layer with the first source gas are shown in Table 1-1, the composition of the first source gas is shown in Table 1-2, and the second source The film formation conditions of the bonding layer by the gas are shown in Table 2-1, the composition of the second source gas is shown in Table 2-2, the composition of the third source gas is shown in Table 3, and the third source gas The film forming conditions of the titanium aluminum nitride film are shown in Table 4, the composition of the obtained bonding layer, the crystal structure and the continuity of the lattice are shown in Table 5, and the composition of the obtained titanium aluminum nitride film is shown in Table 6. The crystal structure, the presence or absence of peeling, and the tool life of the obtained hard film are shown in Table 7.

Note: (1) There is no applicable condition.

Note: (1) There is no applicable condition.

Note: (1) There is no applicable condition.

Note: (1) There is no applicable condition.

Note: (1) Continuity of plaid at the interface between the bonding layer and the lower layer.
(2) Continuity of the lattice at the interface between the bonding layer and the titanium aluminum nitride film.
(3) Not measured.

Note: (1) Titanium aluminum nitride film.

  As is apparent from Tables 5 and 7, the hard films of Examples 1, 8 and 15 in which the microstructures of the interface between the lower layer and the bonding layer and the interface between the bonding layer and the titanium aluminum nitride film were subjected to TEM observation In the coated tool, more than 30% of the crystal lattice was continuous at both interfaces, and the tool had a long life. On the other hand, in the hard-coated tool of Comparative Example 1, the bonding layer was not formed, and the tool had a short life.

1: CVD furnace
2: Chamber
3: Heater
4: Shelf
4a: Central opening of the shelf
5: Reaction vessel
8: Insert for milling
9: Indexable rotary tool
11: The first pipe
11a: 1st pipe nozzle
12: The second pipe
12a: The nozzle of the second pipe
13: Discharge pipe
20: Insert base for milling
21: WC base cemented carbide substrate
22: Lower layer (TiCN film)
23: Titanium aluminum nitride film
25: Bonding layer
30, 40, 50, 80: pipe assembly
C ₁ : circumference of the first diameter
C ₂ : The circumference of the second diameter
D ₁ : First diameter
D ₂ : second diameter
O: Rotation axis
O ₁ : central axis of the first pipe
O ₂ : Central axis of second pipe
R ₁ : radius of the first pipe
R ₂ : radius of second pipe θ: central angle

Claims (7)

A tool substrate, a lower layer of an fcc structure composed of any one kind of single layer film of titanium carbonitride, titanium nitride and titanium zirconium carbonitride by chemical vapor deposition, and Ti _{x 1} Al _{y 1} N (wherein a hard film having an fcc structure titanium aluminum nitride film having a composition represented by x1 and y1 in atomic ratio satisfying x1 = 0.25 to 0.05, y1 = 0.55 to 0.95, and x1 + y1 = 1) A coated tool formed by
Having a bonding layer between the lower layer and the titanium aluminum nitride film,
The composition and fcc represented by Ti _{x 2} Al _{y 2} N (where x 2 and y 2 are numbers satisfying atomic ratios x 2 = 0.55 to 0.80, y 2 = 0.45 to 0.20, and x 2 + y 2 = 1 respectively). Has a structure,
30% or more of a lattice is continuous at the interface between the lower layer and the bonding layer, and 30% or more of the lattice is continuous at an interface between the bonding layer and the titanium aluminum nitride film Hard-coated tools. The hard-coated tool according to claim 1, wherein the layer thickness of the bonding layer is 2 to 50 nm. In the method of manufacturing the hard-coated tool according to claim 1 or 2,
(1) chemical vapor deposition apparatus mounted with the tool substrate, mixed consisting of (a) TiCl ₄ gas, AlCl ₃ gas, a mixed gas A ₁ consisting of N ₂ gas and H ₂ gas, N ₂ gas and H ₂ gas after supplying a first material gas consisting of the gas B ₁ Tokyo, (b) TiCl ₄ gas, AlCl ₃ gas, a mixed gas a ₂ consisting of N ₂ gas and H ₂ gas, NH ₃ gas, N ₂ gas and by supplying the second material gas comprising a mixed gas B ₂ Metropolitan consisting H ₂ gas, to form the bond layer, then
(2) TiCl ₄ gas, AlCl ₃ gas, a mixed gas A ₃ consisting of N ₂ gas and H ₂ gas, the third material consisting of NH ₃ gas, consisting of N ₂ gas and H ₂ gas mixed gas B ₃ Metropolitan Forming the titanium aluminum nitride film by supplying a gas. In the method of manufacturing a hard-coated tool according to claim 3,
The first source gas is a total of 100% by volume of TiCl ₄ gas, AlCl ₃ gas, N ₂ gas and H ₂ gas, 0.18 to 0.77% by volume of TiCl ₄ gas, 0.06 to 0.35% by volume of AlCl ₃ gas , 4-15% by volume of N ₂ gas, and the mixed gas a ₁ the balance being H ₂ gas, consisting 4-15% by volume of N ₂ gas, and the mixed gas B ₁ Metropolitan balance consisting H ₂ gas,
The second source gas is a mixture of TiCl ₄ gas, AlCl ₃ gas, NH ₃ gas, N ₂ gas and H ₂ gas as 100% by volume, 0.18 to 0.77% by volume of TiCl ₄ gas, 0.06 to 0.35% by volume AlCl ₃ gas, 4-15% by volume of N ₂ gas, and the mixed gas a ₂ the balance being H ₂ gas, 0.85 to 1.5% by volume of NH ₃ gas, 4-15% by volume of N ₂ gas, and the balance It consists of mixed gas B ₂ consisting of H ₂ gas,
The third source gas is composed of TiCl ₄ gas, AlCl ₃ gas, NH ₃ gas, N ₂ gas and H ₂ gas in a total volume of 100% by volume, 0.02 to 0.31% by volume of TiCl ₄ gas, 0.15 to 0.8% by volume AlCl ₃ gas, 4.9 to 21.8% by volume of N ₂ gas, and the mixed gas a ₃ the balance being H ₂ gas, 0.7 to 1.9% by volume of NH ₃ gas, 3 to 16.5% by volume of N ₂ gas, and the balance A method comprising: mixing gas B ₃ comprising H ₂ gas. In the method for manufacturing a hard-coated tool according to claim 3 or 4,
Using a chemical vapor deposition apparatus comprising first and second pipes rotating about an axis of rotation O,
The first pipe has a first nozzle,
The second pipe has a second nozzle,
The distance H ₁ between the rotation axis O between the gas jetting port of the first nozzle longer than the distance of H ₂ and the rotary shaft O and spout of said second nozzle,
A method, wherein the mixed gases A ₁ , A ₂ and A ₃ are sequentially ejected from the first nozzle, and the mixed gases B ₁ , B ₂ and B ₃ are sequentially ejected from the second pipe. . The method of manufacturing a hard film-coated tool according to claim 5, wherein the the ratio of the distance H ₁ and the distance H ₂ of (H ₁ / H ₂₎ in the range of 1.5 to 3. A method according to any one of claims 3 to 6, characterized in that a reaction pressure of 3 to 6 kPa and a reaction temperature of 750 to 830 ° C are used.