JP6507458B2 - Method of manufacturing surface coated cutting tool - Google Patents

Description

  The present invention relates to a surface-coated cutting tool and a method of manufacturing the same.

BACKGROUND Conventionally, surface-coated cutting tools having a coating formed on a substrate have been used. For example, in Japanese Patent Application Laid-Open No. 2013-063504 (Patent Document 1), when the inclination angle formed by the normal to the (0001) plane of Al ₂ O ₃ crystal grains is measured with respect to the normal to the surface of the tool substrate, There has been proposed a surface-coated cutting tool having a coating including an upper layer in which an area ratio of Al ₂ O ₃ crystal grains having an inclination angle of 0 to 10 degrees is 45 area% or more.

In JP 2007-125686 A (patent document 2), the Al ₂ O ₃ layer contained in the film preferably contains columnar α-Al ₂ O ₃ crystal grains in the <001> growth direction, and TC Cutting tool inserts have been proposed which have a texture factor of (006)> 1.4.

Unexamined-Japanese-Patent No. 2013-063504 JP 2007-125686 A

The surface-coated cutting tools proposed in the above Patent Documents 1 and ₂ improve the strength and thermal conductivity of the film by the (001) orientation of the α-Al ₂ O ₃ layer, and the chemistry represented by crater wear There is an effect that can reduce However, if the orientation in a specific direction becomes too high, cracks may easily develop at grain boundaries, which may cause sudden chipping of the film.

  The present invention has been made in view of the above-described circumstances, and maintains high thermal conductivity by controlling the orientation of the cutting edge portion relatively low while maintaining high orientation in a specific direction as the entire tool, and An object of the present invention is to provide a surface-coated cutting tool capable of suppressing sudden chipping and a method of manufacturing the same.

A surface-coated cutting tool according to an aspect of the present invention is a surface-coated cutting tool having a rake surface, a flank surface, and a ridge line bordering the rake surface and the flank surface, the substrate and the base and a coating formed on the timber, the coating film comprises α-Al ₂ O ₃ layer comprising crystal grains of a plurality of α-Al ₂ O _3, the α-Al ₂ O ₃ layers, the blade away A first area comprising a ridge line, an area A on the rake surface, and an area B on the flank surface, and an area excluding the A area on the rake surface and an area covered by the coating A second area and a third area which is an area excluding the B area in the flank surface, the A area is a point 1 mm apart from the edge line along the edge line in the rake face A region between the imaginary line passing through the edge and the edge of the cutting edge, and the region B corresponds to the edge of the cutting edge at the flank surface. And an area between the edge line and the imaginary line passing 1 mm from the edge line, and the average value of the first area of TC (006) in the orientation index TC (hkl) is a. When the average value in the second region or the third region of the TC (006) is b, the relationship of b−a> 0.5 is satisfied.

  According to the above, high thermal conductivity can be maintained, and sudden chipping of the cutting edge can be suppressed.

In order to calculate TC (hkl) using an X-ray diffraction method, it is an explanatory view schematically showing five measurement points on a surface coated cutting tool to which X-rays are irradiated. When surface treatment is performed, it is explanatory drawing which showed typically the direction (angle) to which a blast is irradiated with respect to a blade edge ridgeline.

Description of the embodiment of the present invention
First, the embodiments of the present invention will be listed and described.

[1] A surface-coated cutting tool according to an aspect of the present invention is a surface-coated cutting tool having a rake face, a flank face, and a cutting edge line forming the rake face and the flank face. And a film formed on the substrate, the film including an α-Al ₂ O ₃ layer containing a plurality of α-Al ₂ O ₃ crystal grains, the α-Al ₂ O ₃ layer comprising A first area comprising the cutting edge ridge line, the area A on the rake surface, and the area B on the flank surface, and an area excluding the A area on the rake surface and covered with the coating And the third region which is the region excluding the B region in the flank surface, and the A region is 1 mm from the blade edge along the blade edge in the rake face It is an area sandwiched by an imaginary line passing through a distant point and the edge line, and the B area is the edge area at the flank surface. An area between a virtual line passing a point 1 mm away from the cutting edge along the line and the cutting edge, and the average value of the first area of TC (006) in the orientation index TC (hkl) is a When the average value of the second region or the third region of the TC (006) is b, the relationship of b−a> 0.5 is satisfied. With such a configuration, the surface-coated cutting tool can suppress sudden chipping of the cutting edge while maintaining high thermal conductivity.

  [2] It is preferable that the above a satisfies the relationship of 0.01 <a <7, and the above b satisfies the relationship of 7 <b <8. As a result, high thermal conductivity can be more effectively maintained, and at the same time, sudden chipping of the cutting edge can be effectively suppressed.

[3] When the average value of the first region of TC (104) in the orientation index TC (hkl) is c in the α-Al ₂ O ₃ layer, 0.05 ≦ It is preferable to satisfy the relationship of c / a <1. In particular, the effect of suppressing sudden chipping of the cutting edge can be improved.

  [4] A method of manufacturing a surface-coated cutting tool according to an aspect of the present invention includes the steps of: forming the film on the substrate; and performing a surface treatment on a portion of the film corresponding to the first region ,including. According to such a configuration, it is possible to manufacture a surface-coated cutting tool capable of suppressing sudden chipping of the cutting edge while maintaining high thermal conductivity.

[5] The surface treatment preferably includes at least brushing or blasting. Thereby, it is possible to advantageously manufacture a surface-coated cutting tool capable of suppressing sudden chipping of the cutting edge while maintaining high thermal conductivity.
Details of the Embodiment of the Present Invention
Hereinafter, embodiments of the present invention (hereinafter also referred to as “the present embodiments”) will be described in more detail.

<Surface coated cutting tool>
The surface-coated cutting tool of the present embodiment has a rake face, a flank face, and a cutting edge that forms a boundary between the rake face and the flank face.

  The rake face refers to a face that is mainly in contact with the chips of the work material during cutting. For example, in the illustration of FIG. 1, the top and bottom surfaces of the surface-coated cutting tool become rake faces. The flank surface mainly refers to a surface opposite to a processing surface (surface newly formed by cutting a work material). For example, in the explanatory view of FIG. 1, the side surface of the surface-coated cutting tool is a flank. The edge line defines the rake surface and the flank surface. In other words, the intersection of the rake face and the flank face is the cutting edge. The cutting edge ridge line is a portion which usually becomes a cutting edge (hereinafter also referred to as a "cutting edge") in a surface-coated cutting tool.

  In addition, the surface-coated cutting tool of the present embodiment includes a substrate and a film formed on the substrate. The coating preferably covers the entire surface of the substrate. However, even if a part of the substrate is not coated with this film or the composition of the film is partially different, it does not deviate from the scope of the present invention.

  The surface-coated cutting tool according to the present embodiment includes a drill, an end mill, an indexable cutting tip for drills, an indexable cutting tip for end mills, an indexable cutting tip for milling, an indexable cutting tip for turning, a metal saw, It can be suitably used as a cutting tool such as a hob, reamer, tap and the like.

<Base material>
As the substrate, any conventionally known substrate of this type can be used. For example, cemented carbides (for example, WC base cemented carbide, WC, and also those containing Co, or those to which carbonitrides such as Ti, Ta, Nb are added), cermets (TiC, TiN, TiCN, etc.) Main component) high speed steel, ceramics (titanium carbide, silicon carbide, silicon nitride, aluminum nitride, aluminum oxide etc), cubic boron nitride sintered body, or diamond sintered body Is preferred.

  Among these various base materials, it is preferable to select a cemented carbide, in particular, a WC-based cemented carbide, or a cermet (in particular, a TiCN-based cermet). These substrates are excellent in the balance of hardness and strength particularly at high temperatures, and have excellent properties as substrates of surface-coated cutting tools for the above-mentioned applications.

  When the surface-coated cutting tool is an indexable cutting insert or the like, the substrate may or may not have a chip breaker. In addition, the shape of the edge line of the cutting edge is a sharp edge that has a sharp shape, honing (a sharp edge is added to the sharp edge), a negative land (chamfered), a combination of honing and a negative land All things, including things, are included. However, in the present specification, when the edge line of the cutting edge is used as a line (without an area) of a portion where the rake face and the flank face intersect, when determining the range of the first region described later, honing or negative land The explanation will be given on the premise of the cutting edge in the state before applying and so on. If honing or negative land or the like is performed, the cutting edge as a line disappears, and it becomes difficult to clearly determine the range of the first region. Therefore, when the surface-coated cutting tool has been subjected to honing or negative land, the line formed by intersecting the rake face and the flank face virtually is regarded as the cutting edge. Do.

<Coating>
Coating includes α-Al ₂ O ₃ layer comprising crystal grains of a plurality of α-Al ₂ O _3. For example, the coating can be composed of a plurality of layers including one or more α-Al ₂ O ₃ layers and further including other layers.

  The coating has an average layer thickness of 3 to 35 μm (3 μm to 35 μm, and in the case where the numerical range is indicated using “to” in the present application, the range shall include upper and lower numerical values). Furthermore, the average layer thickness of the coating is preferably 5 to 20 μm. If this average layer thickness is less than 3 μm, the strength of the coating may be insufficient. When the average layer thickness exceeds 35 μm, when a large stress is applied between the film and the substrate in the intermittent processing, the film may be frequently peeled or broken.

<Α-Al ₂ O ₃ Layer>
The α-Al ₂ O ₃ layer contains crystal grains of α-Al ₂ O ₃ as a main component. “The crystal grains of α-Al ₂ O ₃ are mainly contained” means that among the crystal grains of Al ₂ O ₃ constituting the α-Al ₂ O ₃ layer, the crystal grains of α-Al ₂ O ₃ are 90 It means to occupy more than% by mass. In addition, preferably, crystals of α-Al ₂ O ₃ except in the case where at least one or more crystal grains of β-Al ₂ O ₃ , γ-Al ₂ O ₃ and κ-Al ₂ O ₃ are unavoidably mixed. It means that an α-Al ₂ O ₃ layer is formed from grains.

<First Region, Second Region, and Third Region in α-Al ₂ O ₃ Layer>
The α-Al ₂ O ₃ layer includes a first region comprising a cutting edge, an A region on the rake face, and a B region on the flank face. Furthermore, it includes a second area which is an area excluding the A area in the rake face and which is an area covered by the coating. It also includes a third area which is an area excluding the B area on the flank surface. Here, the region A is a region sandwiched by an imaginary line passing a point 1 mm away from the cutting edge along the cutting edge along the cutting edge and the cutting edge. Region B is a region flanked by an imaginary line passing a point 1 mm away from the cutting edge along the cutting edge and the cutting edge. Further, the first region includes an intersection (hereinafter referred to as a "corner") of a cutting edge, an intersection of the imaginary line, and an intersection where the cutting edge and the imaginary line intersect. The second and third regions do not include the cutting edge.

<TC (006) in the First Region and the Second Region>
In the α-Al ₂ O ₃ layer, when the average value in the first region of TC (006) in the orientation index TC (hkl) is a, and the average value in the second region of TC (006) is b, The relationship of b−a> 0.5 is satisfied. As a result, it is possible to suppress sudden chipping of the cutting edge by controlling the orientation of only the cutting edge portion to be relatively low while maintaining high thermal conductivity while maintaining high uniformity of orientation.

<TC (006) in the third area>
In addition, although the second region is formed on the rake face, there may be a case where it is difficult to measure the orientation index TC (hkl) due to the presence of irregularities on the surface of the rake face. Even in this case, the α-Al ₂ O ₃ layer of this embodiment is an average value in the first region of TC (006), where an average value in the third region of TC (006) is b. The relationship of b−a> 0.5 is satisfied for a. As a result, it is possible to suppress sudden chipping of the cutting edge by controlling the orientation of only the cutting edge portion to be relatively low while maintaining high thermal conductivity while maintaining high uniformity of orientation.

  Here, the orientation index TC (hkl) can be defined as in the following formula (1).

In the formula (1), I (hkl) represents the X-ray diffraction intensity of the (hkl) reflective surface, and I ₀ (hkl) represents a PDF card No. of ICDD. The standard intensity by 00-042-1468 is shown. Moreover, n in Formula (1) shows the number of reflections used for calculation. (Hk1) (012), (104), (110), (006), (113), (024), (116) and (300) are used as reflections. Therefore, n is 8 in the present embodiment.

Also, alpha-Al ₂ and the first region in the O ₃ layer, a point measured at any point of the second region or the third region TC (006) can be shown by the following formula (2).

  In addition, ICDD (registered trademark) is an abbreviation of International Center for Diffraction Data (international diffraction data center). Also, PDF (registered trademark) is an abbreviation of Powder Diffraction File.

  The measurement of TC (hkl) as described above is made possible by analysis using an X-ray diffractometer. TC (hkl) can be measured, for example, using an X-ray diffractometer (trade name: “SmartLab (registered trademark) 3”, manufactured by Rigaku Corporation) under the following conditions.

Characteristic X-ray: Cu-Kα
Tube voltage: 45kV
Tube current: 200mA
X-ray diffraction method: θ-2θ method X-ray irradiation range: A pinhole collimator is used to irradiate X-rays to a range of about 0.3 mm in diameter.

  In this embodiment, the measurement of TC (006) is performed, for example, on the rake face of the surface coated cutting tool. As long as measurement is made on the rake face of the surface-coated cutting tool, a plurality of measurement points for measuring the value of TC (006) can be set at any non-overlapping positions in the first area (A area), Similarly, a plurality of non-overlapping arbitrary positions in the second area can be set. Then, X-rays are irradiated to these measurement points to obtain the value of TC (006), and the average values of a and b can be calculated.

  Also, the measurement of TC (006) may be performed on the flank of the surface-coated cutting tool when it is difficult to measure the orientation index TC (hkl) due to the presence of asperities on the rake face. Also in this case, a plurality of measurement points for measuring the value of TC (006) can be set at arbitrary non-overlapping positions in the first region (region B) on the flank surface, and similarly, the third region Multiple settings can be made at any non-overlapping locations within. Then, X-rays are irradiated to these measurement points to obtain the value of TC (006), and the average values of a and b can be calculated.

  In addition, it is preferable to select a flat part on the measurement area on the first area, the second area and the third area, and to set the measurement points to two or more non-overlapping points. However, in the case where the measurement points are to be set, if they always overlap each other, only one measurement point may be used. If the measured values are clearly outliers, it is also possible to eliminate them.

  As shown in FIG. 1, in the present embodiment, for example, two corners A (two along the diagonal connecting the corner A of the acute angle (θ = 60 °) and the corner C among the four corners of the rake face). Set measurement points (1st measurement point, 2nd measurement point 2, 3rd measurement point 3, 4th measurement point 4, 5th measurement point 5) at intervals of 0.75 mm from the corner which is the intersection of the cutting edge ridge line) be able to. It is possible to obtain X-ray diffraction (XRD: X-Ray Diffraction) data by irradiating X-rays under the above conditions to these measurement points, and calculate the value of TC (006) based on this XRD data. it can. In FIG. 1, the through hole 13 is a hole that penetrates the surface (bottom surface) opposite to the rake surface of the surface-coated cutting tool.

  Here, as described above, the first region is a region (A region) sandwiched between an edge line and an imaginary line passing a point 1 mm away from the edge along the edge line on the rake face, and a relief It consists of a region (region B) sandwiched by an imaginary line passing a point 1 mm away from the cutting edge along the cutting edge on the surface and the cutting edge. For this reason, based on FIG. 1, the first measurement point 1 and the second measurement set at intervals of 0.75 mm from the corners along the diagonal connecting the angle A which is an acute angle (θ = 60 °) and the angle C. Point 2 is included in the first region, and the average value of TC (006) values obtained at these measurement points is the value of a. The second region is a region other than the region to be the A region and covered with a coating on the rake face as described above. Therefore, the third measurement point 3, the fourth measurement point 4 and the fifth measurement point 5 which are set following the first measurement point 1 and the second measurement point 2 at intervals of 0.75 mm along the diagonal line The average value of the values of TC (006) obtained at these measurement points is the value of b. And in this embodiment, the value of b-a exceeds 0.5. The upper limit value of b−a has the upper limit value of TC (006) based on the definition of the above equation (1), so the relationship of b−a <8 holds.

  Although FIG. 1 shows an example in which the measurement points are set diagonally from the corner to the center of the surface-coated cutting tool, the present invention is not limited to this. For example, each of the first region, the second region, and the third region A plurality of measurement points can be set as dispersed as much as possible in the region, and the value of TC (006) may be measured at these measurement points.

  For example, one or two or more points can be set as the measurement points of the first region on an intermediate line between the cutting edge ridge line and an imaginary line passing a point 1 mm away from the cutting edge ridge along the cutting edge ridge line. One or two or more points can be set as a second area measurement point on a line 1 mm away from the boundary with the first area toward the second area, and as the third area measurement point, the first area It is possible to set one point or two or more points on a line separated by 1 mm from the border line to the third area side. In addition to this, if the surface-coated cutting tool is a regular polygon having a quadrangle or more, the measurement points can be set diagonally as in the present embodiment. If the surface-coated cutting tool is circular, it is possible to set measurement points as one arbitrary point on the cutting edge ridge line, or one or more points on a line passing through the center of the circle.

  It is preferable that a, which is an average value in the first region of TC (006), satisfy the relationship of 0.01 <a <7. Moreover, it is preferable that b which is an average value in 2nd area | region of TC (006) satisfy | fills the relationship of 7 <b <8. Also when measuring TC (006) in the third region, it is preferable that b, which is the average value, satisfies the relationship of 7 <b <8. By satisfying these relationships, high thermal conductivity can be maintained more effectively. At the same time, sudden chipping of the cutting edge can be suppressed more effectively.

When a is in the relationship of a ≦ 0.01, the orientation of the α-Al ₂ O ₃ layer in the specific direction in the first region becomes too low, and the desired hardness and strength of the film in the first region are maintained. There is a risk that you will not be able to If 7 ≦ a, the orientation of the α-Al ₂ O ₃ layer in the first region in a specific direction becomes too high, and cracks may easily develop at grain boundaries, which may cause sudden chipping. There is. Further, if the relationship of b ≦ 7 is established, the orientation of the α-Al ₂ O ₃ layer in the specific direction in the entire tool becomes too low, and there is a possibility that high thermal conductivity can not be maintained. In addition, since the upper limit value of TC (006) is 8 from the definition of said Formula (1), the relationship of b <8 is materialized.

<TC (104) in the first region>
When the average value of the first region of TC (104) in the orientation index TC (hkl) is c in the α-Al ₂ O ₃ layer, the relationship of 0.05 <c / a <1 It is preferable to satisfy the relationship.

  In general, as the angle (orientation difference) between the crystal planes to be oriented is larger, the crack is less likely to progress and the effect of suppressing the sudden chipping of the cutting edge can be obtained. On the other hand, it is known that the larger the angle between the crystal planes to be oriented, the lower the thermal conductivity. Therefore, when the angle between the crystal planes to be oriented is about 45 °, there is a possibility that the chipping suppressing effect and the effect of maintaining the thermal conductivity can be highly compatible.

And, since the angle between the (104) plane and the (006) plane is 45 °, in the present embodiment, the (006) oriented α-Al ₂ O ₃ layer is also oriented to the (104) plane. In the first region, an α-Al ₂ O ₃ layer satisfying the relationship of 0.05 <c / a <1 was used. As a result, it is possible to further suppress the development of cracks at grain boundaries and obtain an effect capable of more effectively suppressing sudden chipping of the cutting edge.

  The measurement of TC (104) can be performed based on, for example, the XRD data used for the measurement of TC (006) described above. And if it calculates the value of c / a in this embodiment, it is preferred that it becomes more than 0.05 and less than one.

  When the value of c / a is in the relationship of c / a ≦ 0.05, it becomes insufficient to control the orientation in the specific direction relatively low in the first region, and the chipping of the cutting edge becomes sudden There is a possibility that a sufficient suppression effect can not be obtained. When c / a ≧ 1, the orientation in the specific direction in the first region is too low, and there is a risk that the desired hardness and strength of the film in the first region can not be maintained.

<Other layers>
The coating may include other layers in addition to the α-Al ₂ O ₃ layer as described above. As other layers, TiCNO layer, TiBN layer, TiC layer, TiN layer, TiAlN layer, TiSiN layer, AlCrN layer, TiAlSiN layer, TiAlNO layer, TiAlNO layer, AlCrSiCN layer, TiCN layer, TiSiC layer, CrSiN layer, AlTiSiCO layer, TiSiCN layer, etc. Can be illustrated. Here, when the compound is represented by a chemical formula as described above in the present specification, when the atomic ratio is not particularly limited, any conventionally known atomic ratio is included, and it is not necessarily limited to the stoichiometric range.

  For example, when "TiAlN" is described, the ratio of the number of atoms constituting TiAlN is not limited to Ti: Al: N = 0.5: 0.5: 1, but includes any conventionally known atomic ratio. The same applies to the description of compounds other than "TiAlN". Further, in the present embodiment, the metal element such as Ti, Al, Si, Zr or Cr and the nonmetal element such as N (nitrogen), O (oxygen) or C (carbon) are necessarily stoichiometric. There is no need to make up the composition.

As an example of another layer, for example, a TiCN layer is disposed between the α-Al ₂ O ₃ layer and the substrate. Since this TiCN layer is excellent in abrasion resistance, more suitable abrasion resistance can be imparted to the film. The TiCN layer is preferably formed by MT-CVD (medium temperature CVD), among others. The MT-CVD method can form a film at a relatively low temperature of about 850 to 900 ° C., and can reduce damage to the substrate due to heating during film formation.

  The TiCN layer preferably has an average layer thickness of 5 to 15 μm. More preferably, the average layer thickness of the TiCN layer is 7 to 12 μm. If the average layer thickness is less than 5 μm, there is a possibility that the wear may easily proceed. If the average layer thickness exceeds 15 μm, the chipping resistance may be reduced.

As the other layers, the outermost surface layer and the intermediate layer can be included in the film. The outermost layer is the layer disposed on the outermost side of the coating. The intermediate layer is a layer disposed between the outermost surface layer and the α-Al ₂ O ₃ layer, between the α-Al ₂ O ₃ layer and the TiCN layer, or between the TiCN layer and the substrate. For example, a TiN layer can be exemplified as the outermost layer. For example, a TiCNO layer can be exemplified as the intermediate layer.

<Method of manufacturing surface-coated cutting tool>
The method of manufacturing a surface-coated cutting tool according to the present embodiment includes the step of forming a film on a substrate. In the present embodiment, the film can be suitably produced by forming a film on a substrate by a chemical vapor deposition (CVD) method. When the CVD method is used, the film forming temperature is 800 to 1200 ° C., which is higher than that of the physical vapor deposition method, whereby the adhesion to the substrate is improved. When layers other than the α-Al ₂ O ₃ layer are formed among the films, those layers can be formed under conventionally known conditions.

In order to form the α-Al ₂ O ₃ layer, for example, AlCl ₃ , HCl, CO ₂ , H ₂ S, O ₂ and H ₂ may be used as a source gas. The compounding amounts are 0.5 to 5% by volume of AlCl ₃ , 1 to 5% by volume of HCl, 0.5 to 1% by volume of CO ₂ , 0.5 to 1% by volume of H ₂ S, and the balance is H _Set to ₂ . Further, conditions of the CVD method are a temperature of 950 to 1050 ° C., a pressure of 1 to 10 kPa, and a gas flow rate (total gas amount) of 10 to 150 L / min.

The thicknesses of the α-Al ₂ O ₃ layer and the other layers can be adjusted by appropriately adjusting the film formation time.

  Moreover, the manufacturing method of the surface-coated cutting tool of this embodiment includes the process of surface-treating to the part corresponding to a 1st area | region in a film. In particular, the surface treatment preferably includes at least brushing or blasting. Thereby, it is possible to advantageously manufacture a surface-coated cutting tool capable of suppressing sudden chipping of the cutting edge while maintaining high thermal conductivity.

  Specifically, after forming a film on a substrate as described above, the portion corresponding to the first region of the film is subjected to surface treatment. An example in which blasting, for example, wet blasting is performed as the surface treatment will be described. As shown in FIG. 2, solid fine particles having an average particle diameter of 25 to 100 μm (for example, ceramic abrasive particles having an average particle diameter of 70 μm) are made 10 to 80 ° with respect to a cutting edge 12 (for example, corner) of the surface-coated cutting tool 11. From the tip of the nozzle placed at an angle of (eg, 45 °). At the same time, the surface coated cutting tool 11 is rotated at 15 to 50 rpm with the through hole 13 at the center of the rake face as the axial center.

  At this time, the projection pressure is 0.01 to 0.2 MPa (for example, 0.05 MPa), the projection distance is 2 to 20 mm (for example, 5 mm), the projection time is 5 to 10 seconds, and the concentration of solid fine particles is 1 to 10% by volume ( The remainder can be a liquid containing water as a main component. Furthermore, as the surface-coated cutting tool 11 rotates, the distance from the blade edge 12 to the tip of the nozzle expands and contracts, so the surface-coated cutting tool is maintained so that the distance between the blade edge 12 and the nozzle tip is always equidistant. Preferably, the rotation of 11 and the movement of the nozzle position are synchronized.

  In addition, you may apply the brush process widely known conventionally, various blast processes (a sand blast process, a shot-peening process etc.) on well-known conditions.

  Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited thereto.

<Preparation of base material>
A raw material powder blended with a composition ratio consisting of 6.5% by mass of Co, 1.2% by mass of TaC, 0.8% by mass of TiC, 1.3% by mass of NbC and the balance of WC After wet mixing for 8 hours with an attritor (wet-type media stirring type pulverizer, trade name (model number): “wet-type attritor 100S”, manufactured by Nippon Coke Kogyo Co., Ltd.), it was dried. Then, it was press-formed into a green compact at a pressure of 100 MPa, and this green compact was put in a vacuum vessel and held at 1400 ° C. for 1 hour in a vacuum of 2 Pa.

Next, the green compact is taken out of the vacuum vessel, and the bottom surface is ground flat, and then a honing of 0.6 mm is performed as a cutting edge treatment viewed from the rake surface with a SiC brush and JIS (Japanese Industrial Standard) B 4120 (2013) A substrate (made by Sumitomo Electric Industries, Ltd.) made of WC cemented carbide in the shape of CNMA 120408 defined in the following was prepared. The prepared base materials were classified into three groups named sample 1 to sample 3 in order to correspond to the formation conditions of _three α-Al ₂ O ₃ layers described later. In addition, two samples were prepared for each group.

<Formation of film>
A film was formed on the surface of each substrate obtained above. Specifically, a film was formed on a substrate by a CVD method by setting the substrate in a CVD apparatus. The formation conditions of a film are as having described in the following Table 1, Table 2, and Table 3. Table 1 shows the formation conditions (temperature conditions, pressure conditions and layer thickness) for producing the α-Al ₂ O ₃ layer and layers other than the α-Al ₂ O ₃ layer, and Table 2 shows the α-Al _{2 layer.} The composition ratio of the source gas for producing each layer other than the O ₃ layer is shown. Table 3 shows the composition ratio of the source gas for producing the α-Al ₂ O ₃ layer. As shown in Tables 1 and 3, the formation conditions of the α-Al ₂ O ₃ layer include three gas conditions of X, Y, and Z, and the substrate to which these gas conditions are applied is Sample 1; The samples were named sample 2 and sample 3.

The layer thicknesses of the layers other than the α-Al ₂ O ₃ layer and the α-Al ₂ O ₃ layer can be adjusted by appropriately adjusting the film formation time. Further, in Tables 1 and 2, MT-TiCN means a TiCN layer formed by MT-CVD method, and HT-TiCN means a TiCN layer formed by HT-CVD (High temperature CVD) method. Do. TiN (first layer) means that a TiN layer was first deposited on the substrate. In the present embodiment, the film configuration is, in order from the substrate side, a TiN layer, an MT-TiCN layer, an HT-TiCN layer, a TiCNO layer, and an α-Al ₂ O ₃ layer. In the present embodiment, the α-Al ₂ O ₃ layer is disposed on the outermost surface of the coating.

<Surface treatment>
The surface treatment was applied to the edge line of each one sample. Specifically, while the surface-coated cutting tool is rotated at a speed of 60 rpm around the through-hole of the rake face as an axis, ceramic abrasive grains of 70 μm in particle diameter are provided from the tip of the nozzle arranged at an angle of 45 °. I applied the treatment. At this time, the projection pressure of the ceramic abrasive grains was 0.05 MPa, the projection distance was 5 mm, the projection time was 5 to 10 seconds, and the concentration was 5% by volume (the balance was a solvent containing water as a main component). In particular, the rotation of the surface-coated cutting tool and the movement of the nozzle were synchronized such that the distance between the cutting edge and the nozzle tip was always 5 mm. Hereinafter, each one of the samples subjected to surface treatment is referred to as Sample 1A, Sample 2A, and Sample 3A. Thus, a surface-coated cutting tool consisting of Samples 1 to 3 and Samples 1A to 3A shown in Table 4 below was produced.

<Measurement of TC (006) and TC (104)>
For each sample, XRD data was obtained by the θ-2θ method using Cu-Kα X-ray, using an X-ray diffractometer (trade name: “SmartLab (registered trademark) 3”, manufactured by Rigaku Corporation). The tube voltage was 45 kV, the tube current was 200 mA, and the X-ray irradiation range was a pinhole collimator, and X-rays were irradiated in the range of 0.3 mm in diameter on the rake face.

  Here, with respect to each sample, the edge line as a line where the rake face and the flank face intersect is honed and disappears, but the rake face and the flank face are virtually extended and these are formed to intersect These lines were regarded as cutting edges, and X-ray irradiation sites were set based on the virtual cutting edges. Specifically, as shown in FIG. 1, along a diagonal line connecting the angle A and the angle C of the acute angle of the rake face (θ = 60 °, the crossing angle of two imaginary cutting edges). Set measurement points (1st measurement point, 2nd measurement point 2, 3rd measurement point 3, 4th measurement point 4, 5th measurement point 5) at intervals of 0.75 mm from the corner of A, and measure these points Were irradiated under the above conditions. Then, the value of TC (006) at each measurement point was calculated from the obtained XRD data.

  In addition, for each sample, the value of TC (104) was also calculated based on the XRD data obtained using the X-ray diffractometer described above. The measurement results are shown in Table 4 below.

  In the present embodiment, the first region includes a region (region A) sandwiched by an imaginary line passing a point 1 mm away from the cutting edge along the cutting edge on the rake face and the cutting edge. Point 1 and second measurement point 2 are included in the first region. In addition, the second area is an area covered by the film except the area which becomes the above-mentioned A area in the rake face, so the third measurement point 3, the fourth measurement point 4 and the fifth measurement point 5 It is included in 2 areas. Therefore, the average value of the values of TC (006) obtained at the first measurement point 1 and the second measurement point 2 becomes the value of a. The average value of TC (006) values obtained at the third measurement point 3, the fourth measurement point 4 and the fifth measurement point 5 is the value of b. The average value of the values of TC (104) obtained at the first measurement point 1 and the second measurement point 2 becomes the value of c.

<Cutting test>
Moreover, the cutting test was performed on each sample under the following conditions.

Work material: FCD 250 round bar Cutting speed: 500m / min
Feeding: 0.2mm / rev
Cutting depth: 1.5mm
Cutting oil: Wet (water-soluble oil)
Evaluation: Measured time to failure (minutes) as life.

  In the cutting test, the cutting tool was set on an NC lathe, the time until the cutting material was cut and a defect occurred in the cutting tool was measured, and this was evaluated as the life. It can be evaluated that sudden chipping of the cutting edge is suppressed although the life is longer as the time until the occurrence of the defect is longer. The results are also shown in Table 4 below.

  In the column of remarks in Table 4, the tool shape change recognized by observing each sample during and after the cutting test was described.

<Test result and consideration>
As shown in Table 4, in the samples 1 and 2, although it is understood from the value of TC (006) that the α-Al ₂ O ₃ layer is oriented (006), the life becomes short from the cutting test. I found that. Observation of the cutting test revealed that chipping of the cutting edge occurred in a short time, and the damage spread from this point. Further, it is understood from the value of TC (006) that samples 3 and 3A do not have (006) orientation of the α-Al ₂ O ₃ layer. When the cutting test was observed, the edge temperature rose due to low thermal conductivity, and plastic deformation occurred, resulting in a short life.

On the other hand, it is understood from the value of TC (006) that the sample 1A and the sample 2A have the (006) orientation of the α-Al ₂ O ₃ layer. Furthermore, due to the effect of the surface treatment, sudden chipping of the cutting edge is suppressed, resulting in obtaining a good life in the cutting test. In particular, it is understood from the value of c / a that the majority of the α-Al ₂ O ₃ layer on the cutting edge is (006) or (104) oriented, and the life is better in cutting test. The result is obtained.

  Moreover, from Table 4, Sample 1A and Sample 2A satisfy the relationship of b−a> 0.5. In particular, it is understood that sample 2A also satisfies the relationship of 0.05 <c / a <1, satisfies the relationship of 0.01 <a <7, and satisfies the relationship of 7 <b <8.

  Therefore, the surface-coated cutting tools of sample 1A and sample 2A do not satisfy the relationship of b−a> 0.5 and 0.05 <c / a <1 in any of sample 1, sample 2, sample 3 and sample 3A. It can be said that it is superior to surface-coated cutting tools in that sudden chipping of the cutting edge can be suppressed while maintaining high thermal conductivity.

  Although the embodiments and examples of the present invention have been described above, it is also planned from the beginning to appropriately combine or variously modify the configurations of the above-described embodiments and examples. .

  It should be understood that the embodiments disclosed herein are illustrative in all respects and not restrictive. The scope of the present invention is shown not by the embodiments described above but by the claims, and is intended to include the meanings equivalent to the claims and all modifications within the scope.

  1 1st measurement point, 2 2nd measurement point, 3 3rd measurement point, 4 4th measurement point, 5 5th measurement point, 11 surface coated cutting tool, 12 cutting edge, 13 through hole.

Claims (3)

And rake face, and a flank, a cutting edge forming the boundary of the rake face and該逃up surface possess,
A substrate and a film formed on the substrate;
The coating comprises an α-Al ₂ O ₃ layer comprising a plurality of α-Al ₂ O ₃ crystal grains,
The α-Al ₂ O ₃ layer is a first region including the cutting edge, the A region on the rake surface, and the B region on the flank surface, and the region excluding the A region on the rake surface. And a second area which is an area covered by the coating, and a third area which is an area excluding the B area in the flank surface,
The region A is a region sandwiched by an imaginary line passing a point 1 mm away from the cutting edge along the cutting edge along the cutting edge and the cutting edge,
The B region, Ru regions der sandwiched between the imaginary line and the edge line of the said flank through a point distant 1mm from the cutting edge along the cutting edge, a manufacturing method of the surface-coated cutting tool ,
Forming the coating on the substrate;
Performing a surface treatment on a portion corresponding to the first region in the coating,
The step of forming the film includes the step of forming the α-Al ₂ O ₃ layer by a CVD method,
In the step of forming the α-Al ₂ O ₃ layer by the CVD method, the temperature is 950 to 1050 ° C., the pressure is 1 to 10 kPa, the gas flow rate is 10 to 150 L / min, and AlCl ₃ is 0.5 to 0.5 5 vol%, a HCl 1 to 5 vol%, the CO ₂ 0.5-1 vol%, the H ₂ S and 0.5 vol%, the raw material gas in the amount of the balance was with H ₂ is used ,
The surface treatment includes blasting,
The blasting process is
From the tip of the nozzle disposed at an angle of 10 to 80 ° with respect to the cutting edge ridge of the surface-coated cutting tool, while rotating the surface-coated cutting tool at 15 to 50 rpm, with the center of the rake face as the axial center The manufacturing method of the surface coating cutting tool including the operation which gives the solid particulates of average particle diameter 25-100 micrometers to the said edge line. The operation to give the solid fine particles is that the projection pressure is 0.01 to 0.2 MPa, the projection distance is 2 to 20 mm, the projection time is 5 to 10 seconds, and the concentration of the solid particles is 1 to 10 volumes The method for producing a surface-coated cutting tool according to claim 1, which is performed under conditions of%. In the surface-coated cutting tool, the average value in the first region of TC (006) in the orientation index TC (hkl) is a, and the average value in the second region or the third region of the TC (006) The method for producing a surface-coated cutting tool according to claim 1 or 2, wherein the relationship of b-a> 0.5 is satisfied when b is b.

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