JP6206800B2 - Method for producing coating film - Google Patents

Description

  The present invention relates to a coating, a cutting tool, and a method for manufacturing the coating, and more particularly, to a coating excellent in oxidation resistance and hardness, a cutting tool including the coating, and a method for manufacturing the coating.

  Conventionally, cutting of steel, castings, and the like has been performed using a cutting tool made of cemented carbide. In such a cutting tool, the cutting edge is exposed to a severe environment such as high temperature and high pressure during the cutting process, and thus the cutting edge tends to be worn or chipped. Thus, there is a problem in the cutting performance of the cutting tool.

Therefore, for the purpose of improving the cutting performance of the cutting tool, development of a coating that covers the surface of a base material such as cemented carbide is underway. In particular, a film made of a nitride containing titanium and aluminum (hereinafter also referred to as “Ti _1-x Al _x N”) can have high hardness and increase the Al content ratio x. Oxidation resistance can be increased. By covering the cutting tool with such a coating, the performance of the cutting tool can be remarkably improved, and further development of the coating is expected.

For example, JP-A-7-205362 (Patent Document 1) discloses a coating film having a multilayer structure in which the composition of a TiN layer and an AlN layer is continuously changed at a cycle of 0.4 nm to 50 nm. It is believed that Ti _1-x Al _x N is present in the period of the multilayer structure. However, since this film is formed by a PVD (Physical Vapor Deposition) method, _x in Ti _1-x Al _x N cannot be designed to be higher than 0.55. For this reason, the oxidation resistance of this film has a limit, and further improvement has been demanded.

On the other hand, Japanese Patent Publication No. 2008-545063 (Patent Document 2) discloses a technique for producing a film made of Ti _1-x Al _x N by a CVD (Chemical Vapor Deposition) method. Patent Document 2 discloses a film having a face-centered cubic structure (hereinafter also referred to as “fcc-type crystal structure”) in which _x in Ti _1-x Al _x N is 0.75 <x ≦ 0.93. It is disclosed.

JP-A-7-205362 Special table 2008-545063 gazette

  However, in the coating disclosed in Patent Document 2, AlN having a hexagonal close-packed structure (hereinafter also referred to as “hcp-type crystal structure”) may be deposited in the fcc-type crystal structure. The deposited hNp-type crystal structure AlN (hereinafter also referred to as “hcp-AlN”) exists as a defect in the film, and decreases the hardness and oxidation resistance of the film.

That is, in the conventional film, Ti _1-x Al _x N is that difficult to sufficiently exhibit the characteristics of both high hardness and high oxidation resistance can be exhibited, and therefore, Ti _1-x Al _x N However, a coating having high hardness and high oxidation resistance that can be exhibited has not been realized, and the improvement of the performance of the cutting tool by the coating has not been achieved.

The present invention has been made in view of the current situation as described above, and the object of the present invention is a coating film having high hardness and high oxidation resistance that Ti _1-x Al _x N can exhibit. Is to provide.

The present invention is composed of one or more layers, and at least one of the layers is formed by alternately laminating a first unit layer made of TiN and a second unit layer made of Ti _1-x Al _x N. The first unit layer has an fcc-type crystal structure, the second unit layer has an fcc-type crystal structure, and _x in Ti _1-x Al _x N is 0.6 or more and 0.00. It is a film which is 9 or less.

Moreover, this invention is a cutting tool containing a base material and the said film which coat | covers this base material.
Moreover, this invention is a manufacturing method of the coating film comprised by the 1 or 2 or more layer formed on a base material, Comprising: CVD which forms at least 1 layer of this layer using CVD method The CVD process includes a step of jetting a first gas containing titanium and aluminum and a second gas containing nitrogen toward the base material, and the base material after the jetting process for 30 minutes or more. Production of a film comprising an annealing process for annealing under a heating condition of 850 ° C. or more and 1000 ° C. or less for a period of minutes or less, and a cooling process for cooling the annealed substrate at a cooling rate of 7 ° C./min or more. Is the method.

In the present invention, _{x in} the second unit layer made of Ti _1-x Al _x N can be maintained at a high value of 0.6 or more and 0.9 or less, and hcp-AlN is precipitated in the second unit layer. Can be suppressed. Therefore, according to the present invention, it is possible to maximize the characteristics that Ti _1-x Al _x N can exhibit, and thus it is possible to provide a film having high hardness and high oxidation resistance.

It is the figure where the film concerning this embodiment was provided on the substrate, and the film consists of one layer, and is a figure showing a TEM photograph corresponding to the case where the one layer is a layer including a multilayer structure. is there. It is a figure which shows the TEM photograph which expanded the principal part of FIG. It is a schematic sectional drawing of the CVD apparatus used for the CVD process in the manufacturing method of this embodiment.

[Description of Embodiment of Present Invention]
First, an outline of an embodiment of the present invention will be described.

The inventors of the present invention have made various studies in order to realize a film that can sufficiently exhibit both the high hardness of Ti _1-x Al _x N and the high oxidation resistance by increasing the Al content ratio x. Piled up.

Specifically, first, the present inventors have difficulty in designing the content ratio x to a value higher than 0.55 by the PVD method. _An attempt was made to produce a coating composed of _1-x Al _x N. As a result of various studies, it has been found that the frequency of hcp-AlN precipitation increases as x increases, and in particular, the precipitation of hcp-AlN is significant when x is 0.7 or more.

Such precipitation of AlN occurs when _x in Ti _1-x Al _x N (hereinafter, also referred to as “fcc-Ti _1-x Al _x N”) having an fcc-type crystal structure is large, particularly 0.7 or more. This is considered to be caused by a large distortion in the crystal structure. That is, in fcc-Ti _1-x Al _x N, a phase transition occurs in order to make the crystal structure a more stable crystal structure, thereby causing TiN having an fcc-type crystal structure (hereinafter also referred to as “fcc-TiN”). ) And hcp-AlN are considered to precipitate. The deposited hcp-AlN exists as a defect in the film as described above, and causes a decrease in the hardness and oxidation resistance of the film.

Therefore, the present inventors have made extensive studies to suppress the phase transition of Ti _1-x Al _x N. In the coating, fcc-Ti _1-x Al _x N is not simply present as one single layer, but a layer composed of fcc-Ti _1-x Al _x N is formed from fcc-TiN in the thickness direction. It was found that the above-described phase transition can be suppressed by adopting a structure sandwiched between layers, and the coating according to the present invention and a cutting tool having the coating were completed. In addition, the above-mentioned coating film can be produced for the first time by using the production method according to the present invention in which a completely different condition is employed in the CVD method.

(1) That is, the coating film according to this embodiment is composed of one or more layers, and at least one of the layers is composed of a first unit layer made of TiN and Ti _1-x Al _x N. The first unit layer has an fcc-type crystal structure, the second unit layer has an fcc-type crystal structure, and includes Ti _1-x Al _x N. x is a film which is 0.6 or more and 0.9 or less.

According to the coating according to the present embodiment, since the second unit layer made of Ti _1-x Al _x N is alternately stacked with the first unit layer made of TiN, the second unit layer is arranged in the thickness direction. It can be sandwiched between the first unit layers. Thereby, in the second unit layer, _{x of} Ti _1-x Al _x N can be maintained at a high value of 0.6 or more and 0.9 or less, and the precipitation of hcp-AlN in the second unit layer is suppressed. can do. Therefore, the coating film according to the present embodiment can have high hardness and high oxidation resistance.

  (2) In the film according to the present embodiment, preferably, in the X-ray diffraction spectrum of the second unit layer, a peak derived from the (111) plane or the (200) plane shows the maximum intensity. When the peak derived from the (200) plane shows the maximum intensity, the surface of the second unit layer is particularly smooth as compared to other cases, thereby improving the welding resistance of the coating. On the other hand, when the peak derived from the (111) plane shows the maximum intensity, the surface of the second unit layer becomes a particularly stable crystal plane as compared with other cases, thereby improving the hardness of the coating.

  (3) Preferably, in the coating film according to the present embodiment, in the multilayer structure, the distance between the first unit layers adjacent to each other with the second unit layer interposed therebetween is 10 nm or more and 40 nm or less. In this case, the coating can have a particularly high hardness and can also have a high toughness.

  (4) Preferably, in the coating according to this embodiment, the second unit layer has a compressive residual stress whose absolute value is 2 GPa or less. Thereby, the film can have high fracture resistance.

  (5) The cutting tool which concerns on this embodiment is a cutting tool containing a base material and the said film which coat | covers a base material.

  According to the cutting tool according to the present embodiment, since the base material is covered with the coating having the high hardness and the high oxidation resistance, high hardness and high oxidation resistance are exhibited during the cutting process. Therefore, it has excellent cutting performance.

  (6) In the cutting tool according to the present embodiment, preferably, the base material is composed of a WC-based cemented carbide or cermet. Thereby, higher hardness and high oxidation resistance can be exhibited.

  (7) The manufacturing method according to the present embodiment is a method for manufacturing a film formed of one or more layers formed on a substrate, and at least one of the layers is formed by a CVD method. Including a CVD process to be formed. In the CVD process, the first gas containing titanium and aluminum and the second gas containing nitrogen are jetted toward the surface of the base material, and the base material after the jetting process is processed for 5 minutes to 30 minutes. In the following period, the annealing process which anneals on the heating conditions of 850 degreeC or more and 1000 degrees C or less, and the cooling process which cools the base material after an annealing process at a cooling rate of 7 degrees C / min or more are included.

  According to the manufacturing method according to the present embodiment, the base material after the ejection process is annealed under the above conditions, and the subsequent base material is cooled at the cooling rate, thereby forming titanium, aluminum, and nitrogen formed by the ejection process. One layer containing can be phase transitioned (separated and separated) into the first unit layer and the second unit layer, and a layer having the multilayer structure can be formed. Therefore, according to the present embodiment, it is possible to produce a film having the above-described high hardness and high oxidation resistance.

[Details of the embodiment of the present invention]
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following drawings, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated. In addition, in this specification, when the composition of each layer constituting the hard coating is expressed using chemical formulas such as “TiAlN” and “TiN”, when the atomic ratio is not particularly limited, all conventionally known atomic ratios are included, It is not necessarily limited to the stoichiometric range. For example, when “TiN” is simply described, the atomic ratio of “Ti” to “N” is not limited to 50:50 (1: 1), and any conventionally known atomic ratio is included.

≪Coating≫
The coating according to the present embodiment includes one or more layers, and at least one of the layers includes a first unit layer made of TiN and a second unit layer made of Ti _1-x Al _x N. Includes a multi-layer structure stacked alternately. As will be described later, the first unit layer has an fcc-type crystal structure, the second unit layer includes an fcc-type crystal structure, and _x in Ti _1-x Al _x N is 0.6 or more and 0.9 or less. It is. The atomic ratio of "Ti _1-x Al _x N" with "Ti _1-x Al _x" and "N" as in the 50:50 (1: 1) is not limited only to the case of the conventionally known Any atomic ratio of

According to the coating of the present embodiment, in the layer including a multilayer structure (hereinafter also referred to as “multilayer structure-containing layer”), the second unit layer made of Ti _1-x Al _x N is the first unit made of TiN. Since the layers are alternately stacked, the second unit layer can be sandwiched between the first unit layers in the thickness direction. Thereby, in the second unit layer, although the _{x of} Ti _1-x Al _x N can be maintained at a high value of 0.6 or more and 0.9 or less, hcp-AlN is precipitated in the second unit layer. Can be suppressed. Therefore, according to the coating film according to the present embodiment, the characteristics of Ti _1-x Al _x N can be exhibited to the maximum, and thus high hardness and high oxidation resistance can be obtained.

  The total thickness of the coating is preferably 3 μm or more and 30 μm or less. When the thickness of the entire coating is 3 μm or more, it is possible to prevent a decrease in hardness due to the thin thickness of the entire coating. Further, when the thickness of the entire coating is 30 μm or less, chipping of the coating due to the large thickness of the entire coating can be prevented. The thickness of the entire coating is more preferably 5 or more and 20 μm or less, and further preferably 7 μm or more and 15 μm or less.

  The total thickness of such a coating is, for example, that a coating is formed on an arbitrary substrate, cut at an arbitrary position, and a cross section thereof is scanned by a scanning electron microscope (SEM) or a transmission type. It can measure by observing with an electron microscope (TEM: Transmission Electron Microscope). The sample for cross-sectional observation can be produced using, for example, a focused ion beam system (FIB), a cross section polisher (CP), or the like.

  The coating according to the present embodiment can include other layers other than this as long as it includes at least one multilayer structure-containing layer described above, and exhibits the above-described remarkable effects even if other layers are included. be able to. Examples of the other layer include an underlayer provided between the multilayer structure-containing layer and the base material, and a surface protective layer provided on the multilayer structure-containing layer.

<Multilayer structure-containing layer>
Hereinafter, the multilayer structure-containing layer contained in the above-described coating will be described in detail.

  FIG. 1 is a diagram in which a coating according to the present embodiment is provided on a substrate, and the TEM photograph corresponds to a case where the coating is composed of one layer, and the one layer is the multilayer structure-containing layer. FIG. Moreover, FIG. 2 is a figure which shows the TEM photograph which expanded the principal part of FIG.

Referring to FIG. 1 and FIG. 2, the multilayer structure-containing layer constituting the film 10 covering the surface of the substrate 11 includes a first unit layer 12 (light colored portion in the multilayer structure shown in FIG. 2) and a second unit. It includes a multilayer structure in which the layers 13 (dark colored portions in the multilayer structure shown in FIG. 2) are alternately stacked. The first unit layer 12 is made of fcc-TiN, the second unit layer 13 is made of fcc-Ti _1-x Al _x N, and _x in Ti _1-x Al _x N is 0.6 or more and 0.9 or less. .

  The composition of the multilayer structure-containing layer constituting the coating 10 can be measured by, for example, an energy dispersive X-ray spectroscopy (EDX) apparatus attached to SEM or TEM. The crystal structure of each layer can be measured by, for example, an X-ray diffraction (XRD) apparatus. In this embodiment, the case where the film 10 is composed of one layer is illustrated, but even when the film 10 is composed of two or more layers, the composition of each layer constituting the film 10 is measured by the same method. can do. Note that the multilayer structure-containing layer may contain inevitable impurities such as oxygen (O), nitrogen (N), and carbon (C).

  The thickness d of the entire multilayer structure-containing layer is preferably 1 μm or more and 20 μm or less. When the thickness d of the entire multilayer structure-containing layer is 1 μm or more, it is possible to significantly improve the characteristics of the coating 10 derived from the characteristics of the multilayer structure-containing layer. Further, when the thickness d of the entire multilayer structure-containing layer exceeds 20 μm, there is no significant change in the improvement of the characteristics of the coating film 10 derived from the characteristics of the multilayer structure-containing layer, which is not economically advantageous. . The thickness d of the entire multilayer structure-containing layer is more preferably 2 μm or more and 15 μm or less, and further preferably 5 μm or more and 10 μm or less.

  As shown in FIGS. 1 and 2, the multilayer structure-containing layer has a columnar crystal region, and in the columnar crystal region, the major axis direction of the columnar crystal (the direction indicated by each arrow in FIGS. 1 and 2). In contrast, the first unit layer 12 and the second unit layer 13 are alternately laminated. The entire multilayer structure-containing layer may be composed only of columnar crystal regions, and may have other crystal regions in addition to the columnar crystal regions. However, in order to effectively exhibit the superior characteristics of the coating film 10 due to the presence of the multilayer structure, the columnar crystal region having the multilayer structure preferably occupies 50% by volume or more of the multilayer structure-containing layer, more preferably 70. Occupies volume% or more.

  Here, the columnar crystal region refers to a region composed of columnar crystals, and such columnar crystals are normal to the surface of the base material 11 rather than the surface direction of the base material 11 (the horizontal direction in FIG. 1). It grows in the direction approximate to the direction (vertical direction in FIG. 1), in other words, in the thickness direction of the multilayer structure-containing layer. Such a columnar crystal has, for example, a shape with a width (diameter) of 50 to 500 nm and a length with respect to the growth direction of 1000 to 10,000 nm.

  The multilayer structure configured in the columnar crystal region is a multilayer structure in which the first unit layer 12 and the second unit layer 13 are periodically and repeatedly stacked so that the second unit layer 13 is sandwiched between the first unit layers 12. It is. Here, the term “repetitively laminated” means that the first unit layer 12 and the second unit layer 13 are laminated on the first unit layer 12 and the second unit layer 13 as well as the first unit layer 12 and the second unit layer 13 that are alternately laminated. In addition, it includes the case where other third unit layers are alternately and repeatedly laminated in the upper, middle and lower directions. Examples of the third unit layer include a layer made of AlN having an fcc crystal structure (hereinafter also referred to as “fcc-AlN”).

  The first unit layer 12 is made of fcc-TiN as described above. fcc-TiN has a stable crystal structure and has high thermal stability. In addition, since the second unit layer 13 is sandwiched between the first unit layers 12 in the thickness direction, the precipitation of hcp-AlN in the second unit layer 13 can be suppressed. The layer to be formed is preferably the first unit layer 12. Thereby, all the second unit layers 13 can be sandwiched between the first unit layers 12.

As described above, the second unit layer 13 is made of fcc-Ti _1-x Al _x N, and _{x of} Ti _1-x Al _x N is 0.6 or more and 0.9 or less. fcc-Ti _1-x Al _x N in which x is such a high value has a particularly high oxidation resistance as compared with, for example, fcc-Ti _1-x Al _x N in which x is 0.55 or less. Here, when _{x of} Ti _1-x Al _x N is 0.6 or more and 0.9 or less, the average value of Al content in Ti _1-x Al _x N is 0.6 or more and 0.9 or less. It means that there is. Therefore, for example, in the multilayer structure, there is a case where _x of Ti _1-x Al _x N in a region in contact with the first unit layer 12 in the second unit layer 13 is less than 0.6, and for example, the second unit layer In some cases, x of Ti _1-x Al _x N in a region farthest from the neighboring first unit layer 12 among 13, that is, an intermediate region in the thickness direction of the second unit layer 13 may exceed 0.9.

The average value of the Al content ratio in Ti _1-x Al _x N can be calculated as follows, for example. That is, first, with respect to an arbitrary plurality of regions different in the thickness direction and in-plane direction of the second unit layer 13 (for example, at least 5 points separated from each other by 1 nm in the thickness direction and 0.5 μm in the in-plane direction) Analyze the composition. Thereby, composition information in regions located at a plurality of positions in the second unit layer is obtained. Then, by averaging the content of a plurality of Al obtained from the composition information, it is possible to calculate the average value x of the Al content in the Ti _1-x Al _x N.

  Regarding the second unit layer 13, in the X-ray diffraction spectrum of the second unit layer 13, it is preferable that the peak derived from the (111) plane or the (200) plane shows the maximum intensity.

When the second unit layer 13 is grown with the (200) plane of Ti _1-x Al _x N as the growth plane, the peak derived from the (200) plane has the maximum intensity in the X-ray diffraction spectrum. In this case, the surface of the second unit layer 13 tends to be particularly smooth compared to the case where the surface is grown without using the (200) plane as a growth surface. Since the surface of the second unit layer 13 is smooth, each surface of the multilayer structure, and thus the multilayer structure-containing layer itself, becomes smooth, so that the multilayer structure-containing layer can have high welding resistance.

On the other hand, when the second unit layer 13 is grown using the (111) plane of Ti _1-x Al _x N as the growth plane, the peak derived from the (111) plane has the maximum intensity in the X-ray diffraction spectrum. In this case, the surface of the second unit layer 13 tends to be a particularly stable crystal plane as compared with a case where the (111) plane is not grown. Since the surface of the second unit layer 13 is a stable crystal plane, each surface of the multilayer structure, and thus the multilayer structure-containing layer itself, becomes stable, and thus the multilayer structure-containing layer can have high wear resistance.

  Therefore, regarding the coating 10 of the present embodiment, when the peak derived from the (200) plane shows the maximum intensity in the X-ray diffraction spectrum of the second unit layer 13, the welding resistance of the coating 10 can be particularly improved. When the peak derived from the (111) plane shows the maximum strength, particularly the wear resistance of the coating film 10 can be improved.

  In the second unit layer 13, the absolute value of the compressive residual stress is preferably 2 GPa or less. Here, the “compressive residual stress” is a kind of internal stress (intrinsic strain) existing in the coating 10, and is represented by a numerical value “−” (minus) (unit: “GPa” is used in the present invention). Stress. For this reason, the concept that the compressive residual stress is large indicates that the absolute value of the numerical value is large, and the concept that the compressive residual stress is small indicates that the absolute value of the numerical value is small. That is, the absolute value of the compressive residual stress being 2 GPa or less means that the preferable compressive residual stress related to the second unit layer 13 is −2 GPa or more and less than 0 GPa.

  When the absolute value of the compressive residual stress of the second unit layer 13 is 2 GPa or less, an appropriate magnitude of strain is maintained in the multilayer structure-containing layer, and thereby the fracture resistance of the coating 10 is improved. The absolute value of the compressive residual stress of the second unit layer 13 is more preferably 1 GPa or less, further preferably 0.2 GPa or more and 0.8 GPa or less, and further preferably 0.4 GPa or more and 0.8 GPa or less.

The absolute value of the compressive residual stress of the second unit layer 13 can be set to 2 GPa or less when _{x of} Ti _1-x Al _x N constituting the second unit layer 13 is 0.6 or more and 0.9 or less. This is considered to be because the second unit layer 13 is sandwiched between the first unit layers 12. For example, when x is less than 0.6, the second unit layer 13 tends to have a tensile residual stress. When x exceeds 0.9, the compressive residual stress of the second unit layer 13 tends to increase.

Such compressive residual stress can be measured by the sin ² ψ method using an X-ray stress measurement apparatus. Specifically, such compressive residual stress is obtained by measuring the stress at an arbitrary point included in the second unit layer 13 having the compressive residual stress in the coating 10 by the sin ² ψ method, and obtaining an average value thereof. Can be measured. The above arbitrary point is 1 point, preferably 2 points, more preferably 3 to 5 points, still more preferably 10 points or more. Each point when measuring at a plurality of points is the second unit layer 13. It is preferable to select a distance of 0.1 mm or more in the in-plane direction so that the above stress can be represented. In addition, regarding the second unit layer 13 that exists in large numbers in the vertical direction, it is preferable to measure each compressive residual stress of two layers instead of one layer, and more preferably to measure each compressive residual stress of three to five layers. It is preferable to measure the compressive residual stress of each of 10 layers or more.

The sin ² ψ method using X-rays is widely used as a method for measuring the residual stress of a polycrystalline material. For example, “X-ray stress measurement method” (Japan Society of Materials, 1981 stock) The method described in detail on pages 54 to 67 of the company Yokendo) may be used.

  The compressive residual stress can also be measured by using a method using Raman spectroscopy. Such Raman spectroscopy has the merit that local measurement can be performed in a narrow range, for example, a spot diameter of 1 μm. The measurement of residual stress using such Raman spectroscopy is a common one. For example, “Thin film mechanical property evaluation technique” (Sipec (currently renamed Realize Science and Technology Center), 1992 (Published yearly), pages 264 to 271 can be employed.

  Each thickness of the first unit layer 12 and the second unit layer 13 is preferably 3 nm or more and 30 nm or less. When the thickness of each layer is 30 nm or less, the multilayer structure in which the layers are stacked becomes a super multilayer structure in which the layers are periodically and repeatedly stacked. As a result, the hardness and oxidation resistance of the multilayer structure-containing layer can be remarkably improved, and thus the hardness and oxidation resistance of the coating film 10 can be remarkably improved. Moreover, when the thickness of each layer is 3 nm or more, the characteristics of the multilayer structure-containing layer derived from the multilayer structure can be remarkably improved. Each thickness of the 1st unit layer 12 and the 2nd unit layer 13 becomes like this. More preferably, they are 5 nm or more and 25 nm or less, More preferably, they are 10 nm or more and 20 nm or less.

  In addition, when the multilayer structure has other layers such as fcc-AlN, the thickness of the other layers is the first from the viewpoint that the multilayer structure is not uniform and the characteristics of the multilayer structure are not exhibited. Similarly to the unit layer 12 and the second unit layer 13, it is preferably 15 nm or more and 30 nm or less.

  The thickness of each layer can be measured by SEM, TEM, or the like, similar to the thickness of the entire coating. Moreover, each unit layer may be the same thickness or may be different. That is, for example, the plurality of first unit layers 12 may have the same thickness or different thicknesses, and the first unit layer 12 and the second unit layer 13 may have the same thickness. Different thicknesses may be used.

  And the distance between the 1st unit layers 12 adjacent on both sides of the 2nd unit layer 13 becomes like this. Preferably they are 10 nm or more and 40 nm or less. Thereby, since precipitation of hcp-AlN can be suppressed more remarkably, the coating film can have higher hardness. In this case, the coating can have a super multi-layer structure composed of a plurality of thin layers, and thus can have high toughness. Here, the distance between the first unit layers 12 adjacent to each other with the second unit layer 13 interposed therebetween is the distance in the thickness direction between the two first unit layers 12 adjacent to each other with the one second unit layer 13 interposed therebetween. And the shortest distance from the middle in the thickness direction of one first unit layer 12 to the middle in the thickness direction of the other first unit layer 12.

  Therefore, for example, in a multilayer structure in which the first unit layers 12 and the second unit layers 13 are alternately stacked, the distance is a distance corresponding to half the thickness of one first unit layer 12; A distance corresponding to the thickness of the second unit layer 13 adjacent on the first unit layer 12 and half the thickness of the other first unit layer 12 adjacent on the second unit layer 13 It is a value obtained by adding the distance corresponding to. Further, when the multilayer structure further includes a third unit layer, for example, the first unit layer 12, the second unit layer 13, and the third unit layer made of fcc-AlN are alternately and repeatedly stacked on the top, middle, and bottom. The distance is equivalent to half the thickness of one first unit layer 12, and the distance corresponding to the thickness of the second unit layer 13 adjacent on the first unit layer 12. This corresponds to a distance corresponding to the thickness of the third unit layer adjacent on the second unit layer 13 and half of the thickness of the other first unit layer 12 adjacent on the third unit layer. It is a value obtained by adding the distance.

<Other layers>
The coating according to the present embodiment can include other layers as long as it includes at least one multilayer structure-containing layer described above. The other layer includes at least one element selected from the group consisting of titanium (Ti), zirconium (Zr), and hafnium (Hf), nitrogen (N), oxygen (O), carbon (C), boron (B It is preferably a layer made of a compound with one or more elements selected from the group consisting of: In this case, since the other layers can also have a relatively high hardness, the hardness of the entire coating can be further increased. Examples of such compounds include TiN, TiB, TiBN, TiCO, TiBNO, TiCBN, TiCNO, ZrN, ZrCN, ZrN, ZrO ₂ , HfC, HfN, HfCN, and the like. Note that the above compound may be doped with a small amount of other elements.

The other layer is more preferably a layer made of α-alumina (α-Al ₂ O ₃ ) or a layer made of κ-alumina (κ-Al ₂ O ₃ ). Such a layer made of alumina has high oxidation resistance, so that the oxidation resistance of the coating can be further improved. Especially, a coating film can be more excellent in oxidation resistance by making the layer which consists of alumina into a surface protective layer.

≪Cutting tool≫
The cutting tool which concerns on this embodiment is a cutting tool containing a base material and the said film which coat | covers this base material. Since the cutting tool according to the present embodiment has the above-described coating film having high hardness and high oxidation resistance, the hardness and oxidation resistance are drastically improved, and thus has excellent cutting performance. it can.

  Cutting tools that can effectively demonstrate the characteristics of the above coatings include drills, end mills, cutting edge replacement cutting tips for drills, cutting edge replacement cutting tips for end mills, cutting edge replacement cutting tips for milling, and cutting edge replacement types for turning. A cutting tip, a metal saw, a gear cutting tool, a reamer, a tap, etc. can be mentioned.

  As the base material of the cutting tool, a conventionally known material can be used without particular limitation as the base material of such a cutting tool. Examples of such a substrate include tungsten carbide (WC) based cemented carbide, cermet, high speed steel, ceramics, cubic boron nitride sintered body, diamond sintered body, and the like. Especially, it is preferable that a base material is a WC group cemented carbide or a cermet from a viewpoint of balance of hardness and toughness.

  The coating of the cutting tool does not necessarily need to cover the entire surface of the base material, and may be formed on at least a part of the surface, for example, at least a part of the rake face and the flank face. By being formed on a part of these surfaces, when a workpiece is processed using a cutting tool, beneficial effects due to its high hardness and high oxidation resistance can be exhibited. In addition, since the detail of the film which the cutting tool which concerns on this embodiment has is the same as that of the above-mentioned, the description is not repeated.

≪Manufacturing method≫
The said film can be manufactured with the manufacturing method which concerns on this embodiment. That is, the coating film manufactured by the manufacturing method according to the present embodiment can have high hardness and high oxidation resistance. Moreover, the said cutting tool can be manufactured by providing the said film | membrane in the base material for cutting tools.

  Here, when the above-mentioned film has other layers other than the multilayer structure-containing layer, conventionally known CVD methods can be suitably used for these other layers. On the other hand, the multilayer structure-containing layer of the above-described film cannot be produced by a conventionally known CVD method, and can be produced for the first time by the following specific CVD process.

  That is, the manufacturing method according to the present embodiment is a manufacturing method of a film formed of one or more layers formed on a substrate, and at least one of the layers is subjected to a CVD method. A CVD process formed using the CVD process, wherein the CVD process includes jetting a first gas containing titanium and aluminum and a second gas containing nitrogen toward the base material, and a base material after the jetting process. An annealing process for annealing treatment under a heating condition of 850 ° C. or more and 1000 ° C. or less for a period of 5 minutes to 30 minutes, and a cooling process for cooling the substrate after the annealing process at a cooling rate of 7 ° C./min or more, It is a manufacturing method of the film containing this. Hereinafter, the CVD process for producing the multilayer structure-containing layer will be described in detail.

<CVD process>
The CVD step is a step of forming a multilayer structure-containing layer, which is at least one of the layers constituting the above-described film, by a CVD method. In this CVD process, the CVD apparatus shown in FIG. 3 can be used.

  With reference to FIG. 3, a plurality of base material setting jigs 22 for holding the base material 11 can be installed in the CVD apparatus 21, and these are covered with a reaction vessel 23 made of heat resistant alloy steel. In addition, a temperature control device 24 is disposed around the reaction vessel 23, and the temperature inside the reaction vessel 23 can be controlled by the temperature control device 24.

  An introduction pipe 27 having two introduction ports 25 and 26 is disposed in the reaction vessel 23. The introduction tube 27 is disposed so as to penetrate the region where the base material setting jig 22 is disposed, and a plurality of through holes are formed in the vicinity of the base material setting jig 22. In the introduction pipe 27, the respective gases introduced into the pipes from the introduction ports 25 and 26 are introduced into the reaction vessel 23 through different through holes without being mixed in the introduction pipe 27. The introduction pipe 27 can rotate with the axis as a central axis. Further, an exhaust pipe 28 is disposed in the CVD apparatus 21, and the exhaust gas can be discharged from the exhaust port 29 to the outside. Note that jigs and the like in the reaction vessel 23 are usually made of graphite. Each step to be described later will be described with reference to FIG.

<Ejection process>
In this step, a first gas containing titanium and aluminum and a second gas containing nitrogen are ejected toward the substrate. Prior to carrying out this step, the base material 11 is arranged on the base material setting jig 22 in the reaction container 23 of the CVD apparatus 21 so that the film forming site is exposed in the reaction container 23. Further, the inside of the reaction vessel 23 is maintained in a high temperature and reduced pressure environment.

  Referring to FIG. 3, in this step, the first gas is introduced from the introduction port 25 into the introduction tube 27, and the second gas is introduced from the introduction port 26 into the introduction tube 27. Further, the introduction pipe 27 at this time is rotated around its axis as shown by a rotation arrow in the drawing by a drive unit (not shown).

  Since a plurality of through holes are opened on one end side (upper side in the drawing) of the introduction pipe 27, the introduced first gas and second gas are jetted into the reaction vessel 23 from a plurality of different through holes, respectively. . Further, since the introduction pipe 27 is rotating, the first gas and the second gas are mixed in the reaction vessel 23. Therefore, in this step, a mixed gas in which the first gas and the second gas are mixed is ejected onto the surface of the base material 11 installed in the base material setting jig 22. As a result, the mixed gas reaches the exposed surface of the substrate 11, and a TiAlN layer is formed as a growth layer using the elements contained in the mixed gas as the composition component.

Examples of the first gas containing titanium and aluminum include a gas containing TiCl ₄ gas and AlCl ₃ gas. An example of the second gas containing nitrogen is a gas containing NH ₃ . Further, the carrier gas may be introduced from the introduction port 25 together with the first gas, or the carrier gas may be introduced from the introduction port 26 together with the second gas. Examples of the carrier gas include H ₂ gas, N ₂ gas, Ar gas, and the like.

  In this step, the temperature in the reaction vessel 23 is preferably 700 ° C. or more and 900 ° C. or less, and the pressure in the reaction vessel 23 is preferably maintained at 0.1 kPa or more and 13 kPa or less. Thereby, the TiAlN layer can be efficiently formed.

Moreover, the thickness of the growth layer can be controlled by adjusting the execution time of this step. For example, the thickness of the growth layer can be reduced by shortening the execution time of the ejection step, and the thickness of the growth layer can be increased by increasing the length. The composition of the growth layer can be controlled by adjusting the mixing ratio of the gas containing titanium and the gas containing aluminum in the first gas. For example, the content ratio of Ti in the growth layer can be increased by increasing the mixing ratio of TiCl ₄ gas in the first gas, and conversely, the growth layer can be increased by increasing the mixing ratio of AlCl ₃ gas in the first gas. The content ratio of Al can be increased.

Further, by adjusting the molar ratio of the gas containing titanium and the gas containing aluminum in the first gas in this step, the growth surface of the second unit layer 13 is either the (200) plane or the (111) plane. Can be set to Specifically, by adjusting the molar ratio of AlCl ₃ and TiCl ₄ (AlCl ₃ / TiCl ₄ ) in the first gas to less than 3.0, the growth surface of the second unit layer 13 is the (200) surface. Can be. As described above, such a second unit layer 13 has a peak derived from the (200) plane in the X-ray diffraction spectrum having the maximum intensity. Further, by adjusting the molar ratio of AlCl ₃ and TiCl ₄ (AlCl ₃ / TiCl ₄ ) to 3.0 or more, the growth surface of the second unit layer 13 can be the (111) surface. As described above, such a second unit layer 13 has a peak derived from the (111) plane in the X-ray diffraction spectrum having the maximum intensity.

  The duration of the ejection process and the content ratio of Ti and Al in the growth layer also affect the configuration of the multilayer structure-containing layer formed through the annealing process and the cooling process described later. For example, when the thickness of the growth layer increases, the number of stacking periods of the first unit layer and the second unit layer also tends to increase. Further, when the Ti content ratio in the growth layer is large, the thickness of the first unit layer tends to increase, or the Ti content ratio in the second unit layer tends to increase. On the contrary, when the content ratio of Al in the growth layer is large, the thickness of the second unit layer tends to increase or the content ratio of Al in the second unit layer tends to increase.

<Annealing process>
In this step, the substrate after the ejection step is annealed under a heating condition of 850 ° C. to 1000 ° C. for a period of 5 minutes to 30 minutes. Specifically, in this process, the first gas and the second gas are not introduced from the introduction pipe 27, and the base material 11 after the ejection process is placed in the reaction vessel 23 while continuing to introduce only the carrier gas. In the state as it is, the inside of the reaction vessel 23 is heated to 850 ° C. or more and 1000 ° C. or less for a period of 5 minutes to 30 minutes. Thereby, the base material 11 on which the growth layer is formed is annealed.

<Cooling process>
In this step, the substrate after the annealing step is cooled at a cooling rate of 7 ° C./min or more. Specifically, the inside of the reaction vessel 23 in which the base material 11 after the annealing step is disposed is cooled so that the temperature of the base material 11 decreases at a rate of 7 ° C./min or more. In addition, when the base material 11 after an ejection process is cooled by natural standing, the cooling rate is about 3 ° C./min to 4 ° C./min, and does not exceed 5 ° C./min.

  Although the details of the reason why the above-described multilayer structure-containing layer is formed by performing the CVD process as described above are not clear, the present inventors speculate as follows based on various examination results.

  The growth layer formed by the ejection process is made of TiAlN, but when the Al content is high, the crystal structure of TiAlN is unstable. By subsequently performing an annealing process on the growth layer having such an unstable crystal structure, TiAlN undergoes spinodal decomposition, thereby causing phase separation in the growth layer.

  In the phase separation, after the growth layer made of fcc-TiAlN has a three-layer structure of a layer made of fcc-AlN, a layer made of fcc-TiAlN, and a layer made of fcc-TiN, each element of aluminum and titanium is By dispersing each layer, the layer made of fcc-AlN and the layer made of fcc-TiN become thinner and the layer made of fcc-TiAlN becomes thicker. At the initial stage of the three-layer structure, the layer made of fcc-TiAlN is considered to be extremely thin compared to the layer made of fcc-AlN or the layer made of fcc-TiN.

The layers made of fcc-AlN and the layer made of fcc-TiN become thinner, but the layer of fcc-AlN tends to disappear first because the dispersion rate of aluminum is faster than the dispersion rate of titanium. . Therefore, by appropriately setting the annealing temperature and period as described above, the layer made of fcc-TiN does not disappear and the layer made of fcc-Ti _1-x Al _x N and the layer made of fcc-TiN. Since the layers are alternately stacked and Al is sufficiently dispersed, x of the layer made of Ti _1-x Al _x N may have a high numerical value of 0.6 to 0.9. it can.

However, even if a structure in which layers of fcc-Ti _1-x Al _x N and layers of fcc-TiN are alternately formed is formed in the phase separation process, the film seems to be allowed to stand after that. When it is cooled at a slow speed or when the annealing time is set longer than the above period, the multilayer structure-containing layer cannot be finally formed. This is presumably because the layer made of TiAlN existing during the phase separation phase-separates into hcp-AlN and fcc-TiN so as to have a more stable crystal structure.

On the other hand, in the manufacturing method of the present embodiment, the growth layer is immediately cooled at a high cooling rate of 7 ° C./min or higher after an appropriate annealing treatment. Therefore, the phase separation is stopped at the above-described stage, and as a result, the first unit layer made of fcc-TiN and the second unit layer made of fcc-Ti _1-x Al _x N are alternately stacked. It is considered that a multilayer structure-containing layer including a multilayer structure is formed.

Hereinafter, the present invention will be described in more detail with reference to examples. In the following description, the thickness of each layer is measured by SEM observation or TEM observation of the cross section of the coating as described above, and the Al content ratio x in Ti _1-x Al _x N is the same as that described above. As described above, the compressive residual stress is measured by the sin ² ψ method.

<Base material>
First, the base material L and the base material M shown in Table 1 below were prepared as base materials to be coated. Specifically, first, raw material powders having the composition shown in Table 1 were uniformly mixed. “Remaining” in Table 1 indicates that WC occupies the remainder of the composition (mass%). Next, after pressing this mixed powder into a predetermined shape, it was sintered at 1300-1500 ° C. for 1-2 hours to obtain a cemented carbide base material having a shape of CNMG120408NGU. This shape is manufactured by Sumitomo Electric Hard Metal Co., Ltd., and is the shape of a cutting edge exchangeable cutting tip for turning.

<Coating>
A coating (No. 1 to 21) having the structure shown in Table 2 was produced on the surface of the produced substrate. Thereby, the cutting tool (No. 1-21) by which the film was formed on the base material was obtained.

  In Table 2, the underlayer is the innermost layer of the coating and is a layer in direct contact with the surface of the substrate, the intermediate layer is a layer formed on the underlayer, and the surface layer is a layer formed on the intermediate layer. It is. In addition, when two layers are described in one column, it means that the left layer is a lower layer, and a column indicated only by “-” means that the corresponding layer is not included.

For example, in No. 2 of Table 2, 15. The cutting tool of No. 15 was formed on the surface of the base material M on the surface of the substrate M formed of a TiN layer having a thickness of 1.0 μm and a TiCN layer having a thickness of 3.0 μm, and formed on the formation condition b. An intermediate layer having a thickness of 5 μm is formed, and a surface layer composed of a TiBN layer having a thickness of 0.5 μm and an Al ₂ O ₃ layer having a thickness of 1.0 μm is further formed thereon. The total thickness is 8.0 μm.

The underlayer and the surface layer shown in Table 2 are layers formed by a conventionally known CVD method, and the formation conditions are as shown in Table 3. For example, the row of “TiN (underlayer)” in Table 3 shows the conditions for forming a TiN layer as the underlayer. Referring to Table 3, the TiN layer is formed by placing a substrate in a reaction vessel of a CVD apparatus (environment in the vessel is 6.7 kPa, 915 ° C.), 2 vol% TiCl ₄ gas, 39 It was formed by ejecting a mixed gas composed of 0.7 volume% N ₂ gas and the remaining 58.3 volume% H ₂ gas at a flow rate of 63.8 L / min. The other layers shown in Table 3 have the same description.

On the other hand, among the intermediate layers shown in Table 2 above, No. The intermediate layer which the film | membrane of 1-15 has corresponds to the above-mentioned multilayer structure content layer, and is formed by any of the formation conditions ag. No. The intermediate layer of the films 16 to 18 corresponds to the Ti _1-x Al _x N layer disclosed in Patent Document 1 described above, and is formed according to the formation condition x. No. The intermediate layer of the coatings 19 to 21 corresponds to a layer having a multilayer structure in which the composition of the TiN layer and the AlN layer disclosed in Patent Document 2 described above is continuously changed at a cycle of 0.4 nm to 50 nm. It is formed according to the formation condition y. Details of the formation conditions a to g are shown in Tables 4 and 5.

The formation condition a will be specifically described with reference to Tables 4 and 5. Under the formation condition a, the intermediate layer as the multilayer structure-containing layer was formed as follows. That is, first, as the ejection step, the first gas composed of AlCl ₃ gas and TiCl ₄ gas and the second gas composed of NH ₃ gas are different in the reaction vessel of the CVD apparatus shown in FIG. Each was introduced from the inlet. At this time, the flow rates of AlCl ₃ gas and TiCl ₄ gas were adjusted to be 0.065 mol / min and 0.025 mol / min, respectively, and the flow rate of NH ₃ gas was adjusted to be 0.09 mol / min. .

From the introduction port for introducing the first gas, H ₂ gas (flow rate: 2.9 mol / min) and N ₂ gas (flow rate: 1.0 mol / min) are introduced as carrier gases, and the second gas is introduced. From the introduction port, N ₂ gas (flow rate: 0.9 mol / min) was introduced as a carrier gas.

  In the ejection step, the pressure and temperature in the reaction vessel were maintained at 2.2 kPa and 800 ° C., and the introduction pipe for introducing the first gas and the second gas was rotated about its axis. After this ejection process was continued for 2 hours, the introduction of the first gas and the second gas into the reaction vessel was stopped.

  Next, as the annealing step, the temperature in the reaction vessel after the ejection step was raised to 900 ° C., and this state was continued for 10 minutes to anneal the base material in the reaction vessel. At this time, the pressure in the reaction vessel was maintained at 100 kPa.

  Next, as the cooling step, the inside of the reaction vessel including the substrate after the annealing step is forcibly cooled, thereby lowering the temperature of the substrate at a cooling rate of 15 ° C./min and cooling the formed film. It was. Through the above steps, an intermediate layer that is a multilayer structure-containing layer was formed. Similarly, in other formation conditions b to g, an intermediate layer that is a multilayer structure-containing layer was formed according to the conditions described in Tables 4 and 5.

Regarding the formation condition x, the intermediate layer was formed using the PVD method disclosed in Patent Document 1. Specifically, first, a Ti target was installed in one of the furnaces of the vapor deposition apparatus used for the PVD method, an Al target was installed on the opposite side, and a base material was placed on a central turntable between the targets. . Then, while rotating the turntable at 50 rpm / min, N ₂ gas was introduced into the furnace at 3000 cc / min, and the Ti target and the Al target were evaporated and ionized by vacuum arc discharge. At this time, the pressure and temperature in the furnace were maintained at 1 × 10 ⁻² Torr and 500 ° C., respectively. An intermediate layer having a thickness of 9.0 μm was formed by performing the PVD treatment under these conditions for 600 minutes, and an intermediate layer having a thickness of 5.0 μm was formed by performing the PVD treatment for 340 minutes.

Regarding the formation condition y, the intermediate layer was formed using a conventional CVD method disclosed in Patent Document 2. Specifically, first, as an ejection process, a first gas composed of AlCl ₃ gas and TiCl ₄ gas and a second gas composed of NH ₃ gas are placed in the reaction vessel of the CVD apparatus shown in FIG. Gases were introduced from different inlets. At this time, the flow rates of AlCl ₃ gas and TiCl ₄ gas were adjusted to be 0.0009 mol / min and 0.00015 mol / min, and the flow rate of NH ₃ gas was adjusted to be 0.09 mol / min. . From the introduction port for introducing the first gas, H ₂ gas (flow rate: 2.9 mol / min) and N ₂ gas (flow rate: 1.0 mol / min) are introduced as carrier gases, and the second gas is introduced. From the introduction port, N ₂ gas (flow rate: 0.9 mol / min) was introduced as a carrier gas.

  In the ejection step, the pressure and temperature in the reaction vessel were maintained at 1.0 kPa and 800 ° C., and the introduction pipe for introducing the first gas and the second gas was rotated about its axis. After the ejection process was continued for a predetermined time, the introduction of the first gas and the second gas into the reaction vessel was stopped.

  And after the said ejection process, unlike formation conditions ag, it did not anneal with respect to the base material after an ejection process, and it was made to cool by natural standing, without forcedly cooling a base material . Note that the cooling rate of the base material by natural standing was 3.5 ° C./min. Further, when the ejection process was continued for 5 hours, an intermediate layer having a thickness of 5 μm was formed, and when the ejection process was continued for 10 hours, an intermediate layer having a thickness of 10 μm was formed.

Table 6 shows a detailed configuration of the intermediate layer formed by each of the formation conditions a to g, x, and y. Referring to Table 6, in the multilayer structure-containing layers formed according to the respective formation conditions a to g, the thicknesses of the TiN layer and the Ti _1-x Al _x N layer in each multilayer structure-containing layer are as shown in Table 6. It was equivalent. Further, the Al content ratio x in the Ti _1-x Al _x N layer was 0.6 or more and 0.9 or less as shown in Table 6. Regarding the multilayer structure-containing layer, the number of layers in the laminated structure is as shown in Table 6, and the number of layers was 100 or more. That is, the multilayer structure of the multilayer structure-containing layer is classified as a super multilayer structure. In addition, it was confirmed by TEM observation that the multilayer structure-containing layer has a columnar crystal region, and that the multilayer structure is formed in the columnar crystal region.
The intermediate layer formed under the formation condition x is a layer (AlN / TiN layer) having a laminated structure in which a 4 nm thick TiN layer and a 4 nm thick AlN layer are alternately laminated. Thus formed intermediate layer was a layer formed of a single layer comprising mainly composition of _{Ti 0.1 Al 0.9 N (Ti 0.1} Al 0.9 N layer).

<Characteristics of multilayer structure-containing layer>
As a characteristic of the multilayer structure-containing layer, an X-ray diffraction spectrum of the Ti _1-x Al _x N layer contained in the intermediate layer formed under the formation conditions a to g is observed, and a peak indicating the maximum intensity is present on any surface. It was confirmed whether it originated or not, and the compressive residual stress of the Ti _1-x Al _x N layer was measured by the sin ² ψ method using X-rays. The results are shown in Table 7. Sample No. When the above characteristics were confirmed for the Ti _1-x Al _x N layer contained in the intermediate layer of each coating of 1 to 15, the above characteristics were consistent for each formation condition. The result for each condition is shown.

With reference to Table 7, the Ti _1-x Al _x N layer contained in the intermediate layer formed according to the formation conditions a to e has a peak derived from the (200) plane in the X-ray diffraction spectrum and shows the maximum intensity. In the Ti _1-x Al _x N layer contained in the intermediate layer formed according to f and g, it was confirmed that the peak derived from the (111) plane showed the maximum intensity in the X-ray diffraction spectrum. Further, it was confirmed that the absolute value of the compressive residual stress of the Ti _1-x Al _x N layer was 2.0 GPa or less in the intermediate layer formed under any formation condition.

<Cutting performance evaluation>
No. manufactured Using the cutting tools 1 to 21, the following cutting tests 1 to 5 were performed, and the cutting performance of each cutting tool was evaluated.

<Cutting test 1>
No. shown in Table 8 below. With respect to the cutting tool, the cutting time until the flank wear amount (Vb) reached 0.20 mm was measured under the following cutting conditions, and the final damage form of the blade edge was observed. The results are shown in Table 7. The longer the cutting time, the better the wear resistance. Further, the closer the final damage form is to normal wear, the better the welding resistance.

<Cutting conditions>
Work material: SUS316 round bar peripheral cutting Peripheral speed: 150 m / min
Feeding speed: 0.15mm / rev
Cutting depth: 1.0mm
Cutting fluid: Yes

As is apparent from Table 8, No. 4 Each of the cutting tools 1, 3, 7, and 9 is No. It was excellent in wear resistance as compared with 16, 17, and 19 cutting tools. In the final damage forms shown in Table 8, “normal wear” means a damage form (having a smooth wear surface) composed only of wear without causing chipping or chipping. From this result, the cutting tools (No. 1, 3, 7, 9) coated with the coating containing the multilayer structure-containing layer are the cutting tools (No. 16, 17) coated with the coating containing the AlN / TiN layer. Further, it was confirmed that the cutting tool (No. 19) coated with a coating containing a Ti _0.1 Al _0.9 N layer is superior in wear resistance and thus has excellent cutting performance. This is presumably because the coating including the multilayer structure-containing layer has high hardness and high oxidation resistance as compared with other coatings.

<Cutting test 2>
No. shown in Table 9 below. With respect to the cutting tool, the cutting time until the flank wear amount (Vb) reached 0.20 mm was measured under the following cutting conditions, and the final damage form of the blade edge was observed. The results are shown in Table 9. The longer the cutting time, the better the wear resistance. Further, the closer the final damage form is to normal wear, the better the welding resistance.

<Cutting conditions>
Work material: SUS304 round bar peripheral cutting Peripheral speed: 200 m / min
Feeding speed: 0.15mm / rev
Cutting depth: 1.0mm
Cutting fluid: Yes

As can be seen from Table 9, no. The cutting tools 1, 4, 5, and 8 are No. Compared to the cutting tools 17 and 19, it was excellent in wear resistance and weldability. In the final damage forms shown in Table 9, “normal wear” means a damage form (having a smooth wear surface) that does not cause chipping or chipping and has only wear, and “defect” is broken. The term “chipping” means a small chip generated at the cutting edge part that generates the finished surface. From this result, the cutting tool (No. 1, 4, 5, 8) coated with the coating containing the multilayer structure-containing layer is the cutting tool (No. 17) and Ti coated with the coating containing the AlN / TiN layer. It was confirmed that the cutting tool (No. 19) coated with a coating containing a _0.1 Al _0.9 N layer is superior in wear resistance and welding resistance, and thus has excellent cutting performance. This is presumably because the coating including the multilayer structure-containing layer has high hardness and high oxidation resistance as compared with other coatings.

<Cutting test 3>
No. shown in Table 10 below. With respect to the cutting tool, the cutting time (minutes) until the chipping or chipping occurred in the tool cutting edge was measured under the following cutting conditions. The results are shown in Table 10. The longer the cutting time, the better the fatigue toughness.

<Cutting conditions>
Work material: SCM435 groove material Peripheral speed: 350 m / min
Feed rate: 0.15 mm / s
Cutting depth: 1.0mm
Cutting fluid: Yes

As is clear from Table 10, No. Each of the cutting tools 1, 2, 3, 5, 6 is No. It was excellent in fatigue toughness as compared with the cutting tools of 17, 19, and 20. From this result, the cutting tool (No. 1, 2, 3, 5, 6) coated with the coating containing the multilayer structure-containing layer is the cutting tool (No. 17) coated with the coating containing the AlN / TiN layer. ) And a cutting tool (No. 19, 20) coated with a coating containing a Ti _0.1 Al _0.9 N layer, it was confirmed that the fatigue toughness was superior and therefore the cutting performance was excellent. This is presumably because the coating including the multilayer structure-containing layer has high hardness and high oxidation resistance as compared with other coatings.

<Cutting test 4>
No. described in Table 11 below. With respect to the cutting tool, the number of passes and the cutting distance until the defect or flank wear amount (Vb) became 0.20 mm were measured under the following cutting conditions, and the final damage form of the blade edge was observed. The results are shown in Table 11. A higher number of passes (that is, a longer cutting distance) indicates better wear resistance. Moreover, it shows that it is excellent in impact resistance, so that a final damage form is near normal wear.

  The number of passes means a cutting tool (blade-replaceable cutting tip) from one end to the other end of one side surface (300 mm × 80 mm surface) of the following work material (shape: 300 mm × 100 mm × 80 mm block shape) ) Is repeated with the cutter attached with one sheet, and the number of repetitions is defined as the number of passes. (If the number of passes is accompanied by a numerical value less than a decimal point, the above conditions are met on the way from one end to the other end.) Indicating that this has been reached). The cutting distance means the total distance of the work material cut until reaching the above condition, and corresponds to the product of the number of passes and the length of the side surface (300 mm).

<Cutting conditions>
Work material: FCD700 block material Peripheral speed: 150 m / min
Feeding speed: 0.2mm / s
Cutting depth: 2.0mm
Cutting fluid: None Cutter: WEX3032E (manufactured by Sumitomo Electric Hardmetal Corp.)
Tip: AXMT170508PEER-G1 blade (manufactured by Sumitomo Electric Hardmetal Corp.)

As is clear from Table 11, No. 1 was obtained. Each of the cutting tools 10, 11, 13, 15 is No. Compared to the 18 and 21 cutting tools, the wear resistance was excellent. In the final damage forms shown in Table 11, “normal wear” means a damage form (having a smooth wear surface) that is composed only of wear without causing chipping or chipping. From this result, the cutting tool (No. 10, 11, 13, 15) coated with the coating containing the multilayer structure-containing layer is the cutting tool (No. 18) and Ti coated with the coating containing the AlN / TiN layer. It was confirmed that the cutting tool (No. 21) coated with a coating containing a _0.1 Al _0.9 N layer is superior in wear resistance and thus has excellent cutting performance. This is presumably because the coating including the multilayer structure-containing layer has high hardness and high oxidation resistance as compared with other coatings.

<Cutting test 5>
No. described in Table 12 below. With respect to the cutting tool, the number of passes and the cutting distance until the defect or flank wear amount (Vb) became 0.20 mm were measured under the following cutting conditions, and the final damage form of the blade edge was observed. The results are shown in Table 12. A higher number of passes (that is, a longer cutting distance) indicates better wear resistance. Moreover, it shows that it is excellent in impact resistance, so that a final damage form is near normal wear.

<Cutting conditions>
Work material: SUS304 block material Peripheral speed: 200 m / min
Feeding speed: 0.2mm / s
Cutting depth: 2.0mm
Cutting fluid: None Cutter: WEX3032E (manufactured by Sumitomo Electric Hardmetal Corp.)
Tip: AXMT170508PEER-G1 blade (manufactured by Sumitomo Electric Hardmetal Corp.)

As is clear from Table 12, Each of the cutting tools 10, 12, 13, and 14 is No. Compared to the 18 and 21 cutting tools, both wear resistance and impact resistance were excellent. In the final damage forms shown in Table 12, “normal wear” means a damage form (having a smooth wear surface) that does not cause chipping or chipping and has only a wear, and “chipping” is cut off. It means a small chip generated in the blade. From this result, the cutting tool (No. 10, 12, 13, 14) coated with the coating containing the multilayer structure-containing layer is the cutting tool (No. 18) and Ti coated with the coating containing the AlN / TiN layer. It was confirmed that the cutting tool (No. 21) coated with a coating containing a _0.1 Al _0.9 N layer is superior in wear resistance and thus has excellent cutting performance. This is presumably because the coating including the multilayer structure-containing layer has high hardness and high oxidation resistance as compared with other coatings.

As is clear from the above cutting tests 1 to 5, each cutting tool (No. 1 to 15) provided with the coating including the multilayer structure-containing layer according to the present embodiment is another cutting tool (No. 16 to 16). Compared with 21), the cutting performance was excellent. This is presumably because the coating including the multilayer structure-containing layer has higher hardness and higher oxidation resistance than other TiN / AlN layers and Ti _0.1 Al _0.9 N layers.

  It should be understood that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

DESCRIPTION OF SYMBOLS 10 Multilayer structure containing layer 11 Base material 12 1st unit layer 13 3rd unit layer 21 CVD apparatus 22 Base material setting jig 23 Reaction container 24 Temperature control device 25,26 Inlet 27 Inlet pipe 28 Exhaust pipe 29 Exhaust opening.

Claims (3)

A method for producing a film composed of one or more layers formed on a substrate,
Including a CVD step of forming at least one of the layers using a CVD method;
The CVD step is a jetting step of jetting a first gas containing titanium and aluminum and a second gas containing nitrogen toward the base material,
An annealing step of annealing the base material after the ejection step under a heating condition of 850 ° C. or higher and 1000 ° C. or lower for a period of 5 minutes to 30 minutes;
A cooling step of cooling the base material after the annealing step at a cooling rate of 7 ° C./min or more. The CVD process is performed using a CVD apparatus,
The said CVD apparatus is a manufacturing method of the film of Claim 1 provided with the introduction pipe | tube which introduce | transduces gas into the reaction container and the said reaction container. The introduction pipe includes a first introduction port and a second introduction port,
In the ejection step, the first gas is introduced into the introduction pipe from the first introduction port, the second gas is introduced into the introduction pipe from the second introduction port, and the first gas and the second gas are introduced into the introduction pipe. The manufacturing method of the film of Claim 2 including operation which introduce | transduces gas into the said reaction container, without mixing in the said introduction pipe | tube.