JP4845490B2 - Surface coated cutting tool - Google Patents

Description

  The present invention relates to a surface-coated cutting tool having excellent cutting characteristics such as fracture resistance and wear resistance, in which a hard coating layer is formed on the surface.

Conventionally, as a surface-coated cutting tool in which a hard coating layer is formed on the surface of a substrate, a TiC layer, a TiN layer, a TiCN layer, an Al ₂ O ₃ layer is formed on the surface of a hard substrate such as cemented carbide, cermet, or ceramic. Further, a cutting tool in which a single or multiple hard coating layer such as a TiAlN layer is deposited is widely used.

  In the form of cutting using such a cutting tool, reduction of environmental load is required, and dry cutting without using a cutting fluid has been attracting attention. In such dry cutting, the cutting blade of the cutting tool tends to be very hot, and the work material tends to adhere to the cutting blade. When the work material is welded to the cutting edge of the tool in this way, the cutting edge is altered and a so-called component cutting edge is generated, so that the machining accuracy is lowered or the welded work material falls off the cutting edge. In addition, cutting blade damage such as peeling of the hard coating layer and chipping is likely to occur. Then, this causes a problem such as a cutting edge defect or abnormal wear, resulting in a problem that it is difficult to extend the tool life.

  As for surface-coated cutting tools, it is known that the properties of the cutting edge surface have a great effect on cutting characteristics. For example, Patent Document 1 discloses a hard coating layer made of a multilayer film including an oxide layer. It has been disclosed that by removing a part of the hard coating layer composed of a multilayer film including an oxide layer at the cutting blade of the surface-coated cutting tool that has been formed, the peeling resistance and fracture resistance of the hard coating layer are improved. ing.

Further, Patent Document 2 discloses that a cutting edge and a coating during cutting are polished by polishing the outermost surface of a surface-coated cutting tool on which a hard coating layer has been formed so that the entire tool has a glossy surface. It is disclosed that the coefficient of friction with the work material is reduced to prevent heat generation at the cutting edge and welding of the work material.
JP-A-8-11005 JP 2004-50385 A

  However, as described in Patent Document 1 and Patent Document 2 described above, by simply processing the surface including the cutting edge of the hard coating layer and smoothing the surface, the cutting resistance is reduced and the slidability is improved. However, in the case of dry cutting, since the temperature at the part where the cutting edge and the cutting edge of the work material come into contact with each other becomes extremely high due to the cutting, the work material is easily softened, so the welding of the work material is suppressed. Therefore, there is a problem that tool damage such as detachment of the welded work material, film peeling and chipping of the cutting edge accompanying the work is generated.

  The present invention has been made to solve the above-described problems, and its purpose is to suppress welding of a work material to a cutting blade that is likely to be generated by high-speed cutting or dry processing, in high-speed cutting or dry cutting. Another object of the present invention is to provide a long-life surface-coated cutting tool that exhibits excellent performance.

  The present inventor has solved the above problem by reducing the wettability of water on the surface of the surface-coated cutting tool even if the work material is easily welded by the heat generated in the dry cutting process. This makes it difficult to weld to the surface, and as a result, it can prevent damage such as peeling of the hard film and chipping of the cutting edge when the attached work material is peeled off, which is also excellent in high speed cutting and dry cutting It was found that a surface-coated cutting tool that exhibits cutting performance can be obtained.

That is, the surface-coated cutting tool of the present invention is a surface-coated cutting tool in which a single-layer or multi-layer hard coating layer is formed on the surface of a substrate, and the outermost surface layer of the hard coating layer is an X-ray diffraction analysis. orientation coefficient is the (200) crystal face is calculated at the following equation from the peak intensity detected at _{T C} is 0.4 to 0.9, with an average particle size of titanium nitride of 1 to 3 [mu] m, The contact angle θ of water on the outermost surface of the hard coating layer is in the range of 91 to 140 °.
T _C = [I (200) / I ₀ (200)] [1 / 6Σ (I (hkl) / I ₀ (hkl))] ⁻¹
However,
I (200): X-ray diffraction peak intensity measurement on (200) plane
I ₀ (200): Standard X-ray diffraction peak intensity on the (200) plane of JCPDS card number 6-642
Σ (I (hkl) / I ₀ (hkl)): [Measurement value of X-ray diffraction peak intensity] / [on (111), (200), (220), (311), (222), (400) plane Total value of standard X-ray diffraction peak intensity]

Here, the outermost surface layer of the single hard coating layer or the multiple hard coating layers is calculated by the peak intensity detected by X-ray diffraction analysis and the following formula (200) crystal It is possible to reduce the interfacial energy on the outermost surface of the hard coating layer, and to reduce the wettability of water on the outermost surface of the hard coating layer. This is important because it can be easily optimized within the scope of the invention.
T _C = [I (200) / I ₀ (200)] [1 / 6Σ (I (hkl) / I ₀ (hkl))] ⁻¹
However,
I (200): X-ray diffraction peak intensity measurement on (200) plane
I ₀ (200): Standard X-ray diffraction peak intensity on the (200) plane of JCPDS card number 6-642
Σ (I (hkl) / I ₀ (hkl)): [Measurement value of X-ray diffraction peak intensity] / [on (111), (200), (220), (311), (222), (400) plane Total value of standard X-ray diffraction peak intensity]

Et al is an average particle diameter in the outermost layer of the hard coating layer of the hard coating layer or multiple layers of a single layer is 1 to 3 [mu] m, in particular, be a 1.5～3Myuemu, surface at the outermost surface This is important because the energy can be lowered and the wettability to the work material on the outermost surface can be lowered.

  In addition, it is preferable that the maximum height Rz of the outermost surface of the hard coating layer be in the range of 0.3 to 1.2 μm because the water contact angle θ can be easily adjusted in the above range. .

  According to the surface-coated cutting tool of the present invention, the water contact angle θ on the outermost surface of the hard coating layer formed on the surface of the substrate is in the range of 91 to 140 °, so that the heat due to cutting is very high. In dry cutting that does not use a high cutting fluid, particularly high-speed dry cutting, the work material dissolved by the heat from cutting is less likely to adhere to the surface of the hard coating layer. For this reason, it is possible to prevent film peeling and chipping of the cutting edge that occur when the welded material falls off, and a decrease in roughness of the processed surface due to adhesion of the welded material. As a result, it is possible to prevent the cutting blade from being damaged and to exhibit excellent cutting accuracy even in the cutting processing in which the cutting blade is likely to become a high temperature particularly during cutting.

  In the present invention, the contact angle θ of water on the outermost surface of the hard coating layer can be adjusted by controlling the interfacial energy on the outermost surface of the hard coating layer. Therefore, it is possible to control the interfacial energy on the surface of the hard coating layer by controlling the compatibility of water on the outermost surface of the hard coating layer. That is, the interfacial energy varies depending on the film formation history and the polishing state of the hard coating layer and cannot be directly measured. However, the present invention comprehensively optimizes these conditions to provide a hard coating layer. It is possible to control the interfacial energy on the outermost surface, that is, the contact angle θ of water within a predetermined range. More specifically, when the interface energy at the outermost surface of the hard coating layer is lowered, the contact angle θ of water is increased.

  As a specific method for controlling the contact angle θ of water, for example, when titanium nitride (TiN) is used as the outermost surface layer of the single hard coating layer or the multilayer hard coating layer, a normal method is used. When the titanium nitride film is formed, the wettability with water is good and the water contact angle θ is less than 90 °. According to the present invention, for example, the film forming conditions are controlled to control the single layer or the outermost surface layer. The reason is unknown by controlling the film quality of the titanium nitride crystal in which the orientation to the (200) plane is suppressed, specifically, the above-described orientation coefficient Tc of 0.4 to 0.9. Grain boundary energy and surface energy can be reduced, and the contact angle θ can be within the range of the present invention.

At this time, by increasing the grain size of the crystal grains in the outermost surface layer of the single hard coating layer or the multiple hard coating layers, the number of crystal interfaces is reduced. Energy (grain boundary energy) can be lowered, and the contact angle θ of water can be controlled in a more suitable range. Range of the average grain size of the single layer or the outermost layer is 1 to 3 [mu] m.

  Furthermore, when the outermost surface of the single layer or the outermost surface layer with poor water wettability is polished, the interfacial energy and the water contact angle θ on the outermost surface of the hard coating layer are further controlled within a suitable range. can do. A desirable range of the maximum height Rz on the outermost surface of the hard coating layer is 0.3 to 1.2 μm.

  1 is an enlarged cross-sectional view of a main part of a throw-away tip type cutting tool (hereinafter, the surface-coated cutting tool of the present invention may be simply abbreviated as a tool) in an example of an embodiment of a surface-coated cutting tool of the present invention. 1 and FIG. 2 which is a schematic perspective view thereof.

  1 and 2, the tool 1 is configured to have a hard coating layer 3 on the surface of a base 2. In the example shown in FIG. 1, the hard coating layer 3 includes a first layer 3a having a titanium nitride layer, a second layer 3b having a titanium carbonitride layer, a third layer 3c having a titanium carbonitride layer, and a fourth layer 3d having a fourth layer 3d. The aluminum oxide layer and the fifth layer are composed of the titanium nitride layer of the outermost surface layer 4.

  Here, according to the tool 1 of the present invention, by making the contact angle θ of water on the outermost surface 5 of the hard coating layer 3 within the range of 91 to 140 °, by cutting the outermost surface 5 of the surface coating layer 3. Even if the cutting edge of the tool becomes hot due to the generated heat and the work material is softened, it is possible to make it difficult for a part of the tool to adhere to the outermost surface of the tool 1. Therefore, the hard coating layer 3 does not deteriorate even in the dry cutting process in which the cutting edge is likely to become high temperature, and an excellent tool life can be exhibited.

  That is, if the contact angle θ of water on the outermost surface 5 of the hard coating layer 3 is smaller than 91 °, the work material is welded to the outermost surface 5 during the cutting process in which the cutting edge is likely to become high temperature. As a result, delamination and damage to the cutting edge occur, and the accuracy of the machined surface deteriorates due to the welded work material.

  On the other hand, when the contact angle θ of water on the outermost surface 5 of the hard coating layer 3 exceeds 140 °, the biting of the cutting edge to the work material is deteriorated, and the cutting resistance increases because the sharpness of the tool decreases, Problems such as sudden chipping of the tool 1 and deterioration of the machined surface accuracy due to chatter occur. In addition, the preferable range of the contact angle θ of water on the outermost surface 5 of the hard coating layer 3 is 93 to 120 °, more preferably in consideration of preventing welding of the work material and suppressing an increase in cutting resistance. It is 95-115 degrees.

  Here, as a method for measuring the contact angle θ of water on the outermost surface 5 of the hard coating layer 3, a measuring method such as a meniscograph method or a capillary method can be used, but as shown schematically in FIG. A droplet 6 made of distilled water is placed on the outermost surface 5 of the hard coating layer 3 (outermost surface layer 4), which is the object to be measured, and the droplet 6 is in the periphery of the region in contact with the object to be measured. 6 can be easily and accurately measured by using a sessile drop method for measuring the angle θ formed by the tangent L of 6 and the outermost surface 5 of the object to be measured in accordance with JIS R3257.

  Control of the water contact angle θ on the outermost surface 5 of the hard coating layer 3 can be achieved by comprehensively optimizing the energy of the surface of the hard coating layer 3 and the grain boundaries. The surface energy and grain boundary energy constituting the interfacial energy, in addition to the physical properties such as the film quality, particle size, and surface roughness of the outermost surface layer 4 of the hard coating layer 3, the heat history during film formation, the flow rate of the source gas, Since it varies depending on the overall properties such as conditions relating to the manufacturing method such as the film formation time, it is necessary to comprehensively consider the conditions such as physical properties and manufacturing method.

Further, the titanium nitride having the (200) crystal plane orientation coefficient TC of 0.4 to 0.9 calculated from the peak intensity value detected by the X-ray diffraction analysis of the outermost surface layer 4 and the following formula: If made of the reason is unknown, as possible out to the interface energy of the outermost layer 4 is reduced wettability of water in the outermost layer within the scope of the present invention. The desirable range of the orientation coefficient TC of titanium nitride is 0.5 to 0.8, more desirably 0.6 to 0.8.
T _C = [I (200) / I ₀ (200)] [1 / 6Σ (I (hkl) / I ₀ (hkl))] ⁻¹
However,
I (200): X-ray diffraction peak intensity measurement on (200) plane
I ₀ (200): Standard X-ray diffraction peak intensity on the (200) plane of JCPDS card number 6-642
Σ (I (hkl) / I ₀ (hkl)): [Measurement value of X-ray diffraction peak intensity] / [on (111), (200), (220), (311), (222), (400) plane Total value of standard X-ray diffraction peak intensity]

Et al is, the outermost layer 4 of titanium nitride of the orientation coefficient T _C, an average particle diameter of the outermost layer 4 1 to 3 [mu] m, particularly by the range of 1.2～2Myuemu, the tool 1 hard The grain boundary energy of the outermost surface 5 of the coating layer 3 can be optimized, the water wetting angle of the hard coating layer 3 can be controlled within a predetermined range, and the work material can be applied to the cutting edge as in dry cutting. It is possible to prevent the work material from being welded to the cutting edge even in the process of being easily welded, and to prevent tool damage due to welding such as film peeling.

  In addition, the average particle diameter of the outermost surface layer 4 of the hard coating layer 3 in the tool 1 of the present invention is a structure observation using a scanning electron microscope or a transmission electron microscope for the surface or cross section of the outermost surface layer 4, In an image observed in a visual field region of 100 nm × 100 nm or more, each area of the particles constituting the outermost surface layer 4 is calculated by an image analysis method, and the average area thereof is estimated. It means the diameter of a circle obtained by converting to a circle having an area.

  Further, by setting the maximum height Rz at the outermost surface 5 of the hard coating layer 3 that is the surface of the outermost surface layer 4 within a range of 0.3 to 1.2 μm, characteristic variation over the entire surface of the hard coating layer 3 is achieved. This is desirable because it is possible to easily adjust the water contact angle θ within a more preferable range. Furthermore, even within the range of the maximum height Rz, the arithmetic average roughness Ra on the outermost surface 5 of the hard coating layer 3 that is the surface of the outermost surface layer 4 is in the range of 0.05 to 0.3 μm. This is desirable because it can optimize the surface energy and optimize the water contact angle θ, and can be easily adjusted to a state where the slidability is increased and the welding of the work material can be further prevented.

  Here, as a method of measuring the arithmetic average roughness Ra and the maximum height Rz of the outermost surface 5 of the hard coating layer 3 (outermost surface layer 4), a stylus type surface roughness measurement is performed in accordance with JIS B0601'01. If such a measurement is difficult, use a measuring instrument such as a laser microscope or an atomic force microscope to estimate while scanning the uneven shape on the outermost surface 5 of the hard coating layer 3. It is possible to measure. In the measurement of the surface roughness (Rz, Ra), when a stylus type surface roughness measuring device is used, a cut-off value: 0.25 mm, a reference length: 0.8 mm, a scanning speed: 0.1 mm Measured at / second.

  The material constituting the hard coating layer 3 is selected from one or more elements selected from Group 4, 5, 6 metal elements of the periodic table, Al and Si, and oxygen, nitrogen, carbon, and boron. A single layer or multiple layers of a compound with one or more elements can be suitably used in terms of cutting performance, and in particular, the outermost surface layer 4 is made of titanium nitride. This is desirable because it can be easily controlled within the scope of the invention.

In addition, as the base | substrate 2 used for the tool 1 of this invention, tungsten carbide (WC), titanium carbide (TiC), or titanium carbonitride (TiCN), and the carbide | carbonized_material of the 4th, 5th, 6th group metal of a periodic table depending on necessity. A cemented carbide or cermet in which a hard phase composed of at least one selected from the group of nitrides and carbonitrides is bonded with a binding phase composed of an iron group metal of cobalt (Co) and / or nickel (Ni), Or hard materials such as silicon nitride (Si ₃ N ₄ ), aluminum oxide (Al ₂ O ₃ ) ceramic sintered body, cubic boron nitride (cBN), ultra-hard sintered body mainly composed of diamond, or carbon steel High hardness materials such as metals such as high-speed steel and alloy steel may be used. In the example shown in FIG. 1, the substrate 2 is made of a cemented carbide composed of a hard phase mainly composed of tungsten carbide (WC) and a binder phase composed of cobalt (Co). When the base 2 is made of a cemented carbide, the balance between hardness and toughness is good and stable cutting can be performed for high-speed wet cutting.

(Method for producing surface-coated cutting tool of the present invention)
In order to manufacture the above-described surface-coated cutting tool 1 of the present invention, first, a metal powder is added to an inorganic powder such as a metal carbide, nitride, carbonitride, or oxide that can be formed by firing the hard alloy described above. , Carbon powder, etc., are added and mixed as appropriate, and after molding into a predetermined tool shape by a known molding method such as press molding, cast molding, extrusion molding, cold isostatic pressing, etc., in vacuum or non-oxidizing By baking in an atmosphere, the substrate 2 made of the hard material described above is produced.

  Next, the hard coating layer 3 is formed on the surface of the substrate 2 by, for example, chemical vapor deposition (CVD). Here, for example, when forming the outermost surface layer 4 of the hard coating layer 3, by setting the pressure in the reaction furnace as low as 1 to 30 kPa, the number of atoms in the reaction furnace decreases, When the molecules diffuse on the surface, the molecules diffuse sufficiently and can be crystallized without generating defects, resulting in low surface energy. Therefore, since the interfacial energy at the outermost surface 5 can be reduced, the contact angle θ of water can be controlled within the scope of the present invention.

  For example, the oriented crystallinity in the outermost surface layer 4 can be controlled by setting the source gas concentration with respect to the mixed gas to 0.05 to 1.0% by volume and setting the film forming temperature to a range of 880 to 950 ° C. As a result, the surface energy of the outermost surface layer can be reduced, and the contact angle θ of water can be controlled within the range of the present invention.

More specifically, for example, in order to form a titanium nitride (TiN) layer as the outermost surface layer 4, titanium chloride (TiCl ₄ ) gas is used as a raw material gas in an amount of 0.05 to 0.5% by volume, and as a reaction gas. A mixed gas composed of 25 to 50% by volume of nitrogen (N ₂ ) gas and the remaining hydrogen (H ₂ ) gas as a carrier gas is adjusted, and the temperature in the chamber is set to 880 to 950 ° C. and the pressure is set to 7 to 10 kPa. Orientation coefficient _{T C} of (200) crystal face of the TiN layer when deposited under this condition is likely to be 0.4 to 0.9.

  Next, after the hard coating layer 3 is formed, the surface of the hard coating layer 3 is polished by a polishing method such as brush, elastic grindstone, blasting, etc., so that the surface roughness of the tool 1 is reduced and the outermost surface layer 4 To control the wettability. Here, it is desirable to perform brush polishing as a polishing method. At this time, the average particle diameter of the TiN particles constituting the outermost surface layer 4 can be controlled by controlling the layer thickness for forming the outermost surface layer 4 and the polishing ratio for subsequent polishing. It is possible to adjust the contact angle θ and uniformize the local wettability variation on the outermost surface 5 of the outermost surface layer 4.

  In the example of the above embodiment, the method for forming the hard coating layer 3 by the chemical vapor deposition (CVD) method has been described. However, the method for manufacturing the tool 1 of the present invention is limited to this. Instead, the hard coating layer 3 may be formed by other film forming methods such as physical vapor deposition (PVD). Even in this case, the film formation is performed under the condition that the film quality of the outermost surface layer 4 is controlled by controlling the flow rate of the film forming gas, and the outermost surface 5 of the hard coating layer 3 is polished by the processing method described above. The contact angle of water on the outermost surface 5 of the hard coating layer 3 can be controlled.

  In the example of the above-described embodiment, the case where the hard coating layer 3 is composed of five layers has been described. However, in the tool 1 of the present invention, the hard coating layer 3 is composed of four layers or less, or six layers or more. Even when the hard coating layer 3 is composed of a single layer, the effects of the invention are not lost.

5% by mass of metallic cobalt (Co) powder with an average particle size of 1.2 μm and 0% of titanium carbide (TiC) powder with an average particle size of 2.0 μm with respect to tungsten carbide (WC) powder with an average particle size of 1.1 μm. 0.5% by mass of Cr ₃ C ₂ powder having an average particle size of 2.0 μm was added and mixed at a ratio of 0.5% by mass, and after forming into a cutting tool shape (CNMA1204112) by press molding, the binder removal treatment was performed. Applied and fired at 1450 ° C. for 1 hour in a vacuum of 0.01 Pa to produce a cemented carbide. Further, the manufactured cemented carbide was subjected to cutting edge processing (Honing R) from the rake face by brushing.

Next, a hard coating layer composed of a multilayer film having a structure shown in Table 2 was formed on the cemented carbide alloy by a chemical vapor deposition (CVD) method. The deposition conditions for each layer in Table 2 are shown in Table 1. And after coat | covering a hard coating layer, the surface of a sample is grind | polished by the grinding | polishing method shown in Table 2, and the layer thickness of the outermost surface layer is adjusted to the value of Table 2, and sample No. 1 to 9 surface-coated cutting tools were produced.

  About the flat part of the rake face of the obtained tool, the contact angle θ of water on the surface was measured using a sessile drop method based on JIS R3257 as shown in FIG. The results are shown in Table 2.

  In addition, the surface roughness (maximum height Rz, arithmetic average roughness Ra) of the flat surface such as a land near the cutting edge of the tool is changed to JIS B0601'01 using a stylus type surface roughness measuring instrument. The measurement was performed using a stylus type surface roughness measuring instrument in accordance with a cutoff value of 0.25 mm, a reference length of 0.8 mm, and a scanning speed of 0.1 mm / second. The results are shown in Table 2.

  Furthermore, the hard coating layer of the obtained tool was observed with a transmission electron microscope (TEM) at a magnification of 500,000 times, and the particle size of the outermost surface layer was measured using an image analysis method. The results are shown in Table 2. Specifically, the area of each particle was calculated, and the diameter of the circle when the average value was converted into a circle having the same area was calculated as the average particle diameter of the outermost surface layer.

Further, the outermost TiN layer was subjected to X-ray diffraction analysis using Cu as a tube, and the orientation coefficient _Tc on the (200) plane was determined from the obtained peak intensity. The results are shown in Table 2.

  Then, using this tool, a cutting test was performed under the following conditions to evaluate the performance.

(Cutting conditions)
Work material: SCM440 Cylindrical tool shape: CNMA120408
Cutting speed: 300 m / min Feeding speed: 0.2 mm / rev
Cutting depth: 1.5mm
Cutting condition: Dry evaluation item: Observe the cutting edge with a microscope and measure the amount of flank wear and tip wear

  From Tables 1 to 3, Sample No. with a contact angle θ smaller than 91 ° was obtained. In Nos. 7 and 8, since the work material was welded to the cutting edge, chipping and delamination occurred, both wear resistance and fracture resistance were poor, and the tool life was very short.

  Sample No. with a contact angle θ exceeding 140 ° was used. In No. 9, since the cutting edge of the tool on the work material is poor, cutting resistance increases, chipping of the cutting edge and film peeling occur, and both wear resistance and chipping resistance are deteriorated. It was short.

  On the other hand, Sample No. with a contact angle θ in the range of 91 ° to 140 °. Nos. 1 to 6 were excellent in wear resistance and fracture resistance under the above cutting conditions, and there was almost no damage to the cutting edge.

It is a principal part expanded sectional view which showed the layer structure of the hard coating layer in an example of embodiment of the surface covering cutting tool of this invention. It is a schematic perspective view which shows the external appearance of the throw away tip which is a suitable example of embodiment of the surface covering cutting tool of this invention. It is a schematic diagram for demonstrating the method to measure the contact angle of water in the outermost surface of a hard coating layer.

Explanation of symbols

1: Tool (surface coated cutting tool)
2: Substrate 3: Hard coating layer 4: Outermost surface layer 5: Outermost surface of the hard coating layer 6: Droplet 7: Rake face 8: Flank 9: Cutting edge θ: Contact angle

Claims (2)

A surface-coated cutting tool in which a single-layer or multiple-layer hard coating layer is formed on the surface of a substrate, wherein the outermost surface layer of the hard coating layer is expressed by the following formula from the peak intensity detected by X-ray diffraction analysis in the the (200) orientation coefficient _{T C} of the crystal plane is 0.4 to 0.9 calculated by, with an average particle size of titanium nitride of 1 to 3 [mu] m, the contact of water on the outermost surface of the hard coating layer A surface-coated cutting tool having an angle θ in the range of 91 to 140 °.
T _C = [I (200) / I ₀ (200)] [1 / 6Σ (I (hkl) / I ₀ (hkl))] ⁻¹
However,
I (200): X-ray diffraction peak intensity measurement on (200) plane
I ₀ (200): Standard X-ray diffraction peak intensity on the (200) plane of JCPDS card number 6-642
Σ (I (hkl) / I ₀ (hkl)): [Measurement value of X-ray diffraction peak intensity] / [on (111), (200), (220), (311), (222), (400) plane Total value of standard X-ray diffraction peak intensity] 2. The surface-coated cutting tool according to claim 1 , wherein a maximum height Rz of the outermost surface of the hard coating layer is in a range of 0.3 to 1.2 μm.

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