Coated implement and cutting implement

Abstract

A coated implement according to the present invention comprises a substrate and a coated layer positioned on the substrate. The coated layer contains at least one of aluminum and titanium. The substrate comprises a surface portion including a surface in contact with the coated layer, and a center portion positioned on a side opposite to the coated layer side with respect to the surface portion. The surface portion contains at least one of aluminum and titanium.

Description

Coated and cutting tools

[0001] FIELD OF THE DISCLOSURE Embodiments of the present disclosure relate to coated tools and cutting tools.

[0002] BACKGROUND ART As a tool used in cutting processes such as turning or milling, a coated tool is known in which the surface of a substrate made of cemented carbide, cermet, ceramics, or the like is coated with a coating layer to improve wear resistance and the like.

[0003] For example, in a surface-coated sintered alloy in which a base material made of cemented carbide is coated with a hard film, it is known to use a surface-coated sintered alloy with excellent adhesion in which a diffusion element-containing layer is formed in which one or more of the iron group elements constituting the base material and the diffusion elements, tungsten and carbon, are diffused almost uniformly in the hard film (see, for example, JP 2000-355777 A).

[0004] A coated tool according to one aspect of this embodiment includes a substrate and a coating layer located on the substrate, the coating layer containing at least one of aluminum and titanium, the substrate having a surface portion including a surface in contact with the coating layer and a center portion located on the opposite side of the surface portion from the coating layer, and the surface portion containing at least one of aluminum and titanium.

[0005] Fig. 1 is a perspective view showing an example of a coated tool according to the present embodiment. Fig. 2 is a cross-sectional view showing an example of an insert according to the present embodiment. Fig. 3 is a cross-sectional view showing an example of a coated tool according to the present embodiment. Fig. 4 is a cross-sectional view showing an example of a surface portion of a base according to the present embodiment. Fig. 5 is a diagram showing an example of the distribution of atomic content in the coated tool according to the present embodiment. Fig. 6 is a front view showing an example of a cutting tool according to the present embodiment. Fig. 7 is a diagram showing the distribution of atomic content in the coated tool according to Sample No. 1 of the example. Fig. 8 is a diagram showing the distribution of atomic content in the coated tool according to Sample No. 8 of the comparative example.

[0006] Hereinafter, modes for carrying out a coated tool and a cutting tool according to the present disclosure (hereinafter referred to as "embodiments") will be described in detail with reference to the drawings. The coated tool and the cutting tool according to the present disclosure are not limited to the embodiments described below. In the following embodiments, the same components are designated by the same reference numerals, and redundant description will be omitted.

[0007] For example, when the above-mentioned surface-coated sintered alloy is used for machining with high cutting resistance, the adhesion between the base material and the hard film is insufficient, and the hard film is likely to peel off from the base material and / or chipping of the base material occurs, resulting in the end of the tool's useful life in a relatively short period of time.

[0008] As described above, the prior art has room for further improvement in terms of improving wear resistance and chipping resistance.

[0009] Therefore, there is a need for a technology that can overcome the above-mentioned problems and improve wear resistance and fracture resistance.

[0010] <Coated Tool> Fig. 1 is a perspective view showing an example of a coated tool according to this embodiment. As shown in Fig. 1, the coated tool 1 according to this embodiment has an insert 11.

[0011] (Insert 11) The insert 11 has, for example, a hexahedral shape in which the upper and lower surfaces (surfaces intersecting with the Z axis shown in Fig. 1) are shaped like a substantially parallelogram.

[0012] One corner portion of the insert 11 functions as a cutting edge portion. The cutting edge portion has a first surface (e.g., an upper surface) and a second surface (e.g., a side surface) that is connected to the first surface. In this embodiment, the first surface functions as a "rake face," and the second surface functions as a "flank face." A cutting edge is located on at least a portion of the ridge where the first surface and the second surface intersect, and the coated tool 1 cuts the workpiece by bringing this cutting edge into contact with the workpiece.

[0013] A through-hole 15 is located in the center of the insert 11, penetrating the insert 11 from top to bottom. The central axis of the through-hole 15 may pass through the center of the upper surface and the center of the lower surface. A screw 75 is inserted into the through-hole 15 to attach the coated tool 1 to a holder 70 (described later) (see FIG. 6 ).

[0014] 1 is merely an example and does not limit the shape of the coated tool according to the present disclosure. The coated tool according to the present disclosure may have, for example, a rod-shaped body having a rotation axis and extending from a first end to a second end, a cutting edge located at the first end of the body, and a groove extending spirally from the cutting edge toward the second end of the body.

[0015] Fig. 2 is a cross-sectional view showing an example of an insert according to this embodiment. The cross section shown in Fig. 2 may be a cross section parallel to the central axis of the through hole 15. As shown in Fig. 2, the insert 11 has a base body 2 and a coating layer 3.

[0016] (Substrate 2) The substrate 2 is formed of, for example, a cemented carbide. The cemented carbide contains a hard phase containing at least W (tungsten), specifically WC (tungsten carbide). The cemented carbide may contain a binder phase containing at least one iron group element such as Ni (nickel) and Co (cobalt). As an example, the substrate 2 may be a WC-based cemented carbide whose main component is hard particles made of WC. Here, the main component refers to a cemented carbide containing 80 mass % or more of hard particles made of WC. When the substrate 2 is the above-mentioned cemented carbide, the substrate 2 has better heat resistance.

[0017] The substrate 2 may be a cermet. The cermet contains, for example, Ti (titanium), specifically, TiC (titanium carbide) or TiN (titanium nitride). The cermet may also contain at least one iron group element such as Ni and Co.

[0018] The substrate 2 may be a cubic boron nitride sintered body containing cubic boron nitride (cBN) particles. The substrate 2 is not limited to cubic boron nitride (cBN) particles, and may contain particles of hexagonal boron nitride (hBN), rhombohedral boron nitride (rBN), wurtzite boron nitride (wBN), or the like.

[0019] The substrate 2 may be made of ceramic. The ceramic may be, for example, Al ２ O ３ (aluminum oxide) may be contained. ２ O ３ (Aluminum oxide) includes, for example, κ-Al ２ O ３ and α-Al ２ O ３ The ceramic may contain other elements in addition to aluminum oxide. For example, the ceramic may contain, in addition to aluminum oxide, at least one of magnesium (Mg), calcium (Ca), strontium (Sr), silicon (Si), and elements from Groups 3 and 4 of the periodic table.

[0020] (Coating layer 3) The coating layer 3 coats the substrate 2 for the purpose of improving the abrasion resistance, heat resistance, etc. of the substrate 2. In the example of FIG. 2, the coating layer 3 coats the entire substrate 2. The coating layer 3 is not particularly limited as long as it is located at least on the surface of the substrate 2. When the coating layer 3 is located on the first surface (here, the upper surface) of the substrate 2, the abrasion resistance and heat resistance of the first surface are high. When the coating layer 3 is located on the second surface (here, the side surface) of the substrate 2, the abrasion resistance and heat resistance of the second surface are high.

[0021] <Coated Tool 1> An example of a coated tool according to this embodiment will now be described with reference to Fig. 3. Fig. 3 is a cross-sectional view showing an example of a coated tool according to this embodiment.

[0022] As shown in FIG. 3 , the coated tool 1 according to this embodiment includes a substrate 2 and a coating layer 3 located on the substrate 2. The substrate 2 has a surface portion 21, including a surface in contact with the coating layer 3, and a central portion 22 located on the opposite side of the surface portion 21 from the coating layer 3 side. Hereinafter, the "opposite side of the surface portion 21 from the coating layer 3 side" may also be referred to as the "center side." As will be described later, the surface portion 21 of the substrate 2 is a region containing at least one of aluminum and titanium. The central portion 22 of the substrate 2 is a region containing neither aluminum nor titanium. The term "not containing" as used above does not strictly mean that the material is not contained at all, but rather means that the material is below the detection limit and cannot be detected by normal measurement. In the measurement method using a combination of sputtering and X-ray photoelectron spectroscopy (XPS) described below, the material is considered to be "not containing" if it is not determined to be contained.

[0023] The surface of the substrate 2 in contact with the coating layer 3, i.e., the interface between the substrate 2 and the coating layer 3, is identified, for example, by taking a photograph of a cross section of the coated tool 1 including the substrate 2 and the coating layer 3 using a scanning electron microscope (STEM). When using a measurement method that combines sputtering and XPS, as in this embodiment, the position of the interface between the substrate 2 and the coating layer 3 may be identified, for example, by calculating the average thickness of the coating layer 3, i.e., the average distance from the surface of the coating layer 3 to the interface between the substrate 2 and the coating layer 3, in a photograph of a cross section of the coated tool 1 including the substrate 2 and the coating layer 3. When the surface of the coating layer 3 is flat, the thickness direction refers to the direction perpendicular to the surface of the coating layer 3. When the direction cannot be uniquely identified, the thickness direction refers to the direction perpendicular to the interface between the substrate 2 and the coating layer 3.

[0024] The coating layer 3 contains at least one of aluminum and titanium. For example, the coating layer 3 contains Al ａ Ti ｂ M ｃand at least one nonmetal selected from carbon, nitrogen, and oxygen. M is at least one metal selected from Groups 4, 5, and 6 (excluding Cr) in the periodic table of elements and Si. a, b, and c are 0≦a≦65 and 0≦b≦100, and a+b+c=100. As an example, the composition of the coating layer 3 may be AlTiWNbSiN. The coating layer 3 does not necessarily need to contain M. The notation AlTiWNbSiN indicates the type of constituent elements and does not indicate that the atomic ratio of the constituent elements is equal. In this case, the composition of the coating layer 3 may be, for example, AlTiN. The notation AlTiN indicates the type of constituent elements and does not indicate that the atomic ratio of the constituent elements is equal. The coating layer 3 has high hardness and high oxidation resistance at high temperatures (e.g., 1100°C).

[0025] The thickness of the coating layer 3 may be 1.0 μm or more and 7.0 μm or less. In particular, when the thickness of the coating layer 3 is 1.5 μm or more, the wear resistance of the coated tool 1 is easily improved. When the thickness of the coating layer 3 is 3.0 μm or less, the fracture resistance of the coating layer 3 is easily improved. Therefore, when the thickness of the coating layer 3 is 1.5 μm or more and 3.0 μm or less, the wear resistance and fracture resistance of the coating layer 3 can be improved.

[0026] The surface region 21 of the substrate 2 is a region containing at least one of aluminum and titanium. Specifically, when the coating layer 3 contains aluminum, the surface region 21 of the substrate 2 is a region containing aluminum. When the coating layer 3 contains titanium, the surface region 21 of the substrate 2 is a region containing titanium. The central portion 22 of the substrate 2 is a region containing neither aluminum nor titanium.

[0027] In the coated tool 1, the coating layer 3 contains at least one of aluminum and titanium, and the surface portion 21 of the substrate 2 contains at least one of aluminum and titanium. In this embodiment, at least one of aluminum and titanium contained in the coating layer 3 diffuses into the surface portion 21 of the substrate 2, causing the surface portion 21 of the substrate 2 to contain at least one of aluminum and titanium.

[0028] In this case, the difference between the thermal expansion coefficient of the base 2 and the thermal expansion coefficient of the coating layer 3 is likely to be reduced. In this case, the residual stress caused by the difference between the thermal expansion coefficient of the base 2 and the thermal expansion coefficient of the coating layer 3 is likely to be reduced. This tends to improve the adhesion between the base 2 and the coating layer 3 in the coated tool 1. As a result, it becomes possible to improve the fracture resistance of the coated tool 1.

[0029] In addition, the hardness of the binder phase contained in the substrate 2 is likely to increase, which tends to reduce the occurrence of shedding of hard particles contained in the substrate 2. As a result, the wear resistance of the coated tool 1 can be improved.

[0030] At least one of aluminum and titanium contained in the coating layer 3 and at least one of aluminum and titanium contained in the surface portion 21 of the substrate 2 is detected by, for example, a combination of sputtering and X-ray photoelectron spectroscopy (XPS). Specifically, the surface of the coated tool 1 is scraped away from the coating layer 3 toward the substrate 2 using a sputtering device, and the type of atoms is identified by applying XPS to the atoms that are ejected from the surface of the coated tool 1.

[0031] As mentioned above, "containing aluminum" means that a material is determined to contain aluminum when the aluminum content (atomic %) is detected to be 0.1% or more. Conversely, if the aluminum content (atomic %) is so small that it is difficult to detect (for example, less than 0.1%), it may be considered not to contain aluminum. Similarly, the above-mentioned "containing titanium" means that a material is determined to contain titanium when the titanium content (atomic %) is detected to be 0.1% or more. Conversely, if the titanium content (atomic %) is so small that it is difficult to detect (for example, less than 0.1%), it may be considered not to contain titanium.

[0032] When using a measurement method that combines sputtering and XPS as described above, as in this embodiment, if aluminum is not detected closer to the center than a region at a distance of D×0.5 of the coating layer thickness from the interface between the base 2 and the coating layer 3 toward the center, it is determined that the surface portion 21 of the base 2 does not contain aluminum. Similarly, if titanium is not detected closer to the center than a region at a distance of D×0.5 of the coating layer thickness from the interface between the base 2 and the coating layer 3 toward the center, it is determined that the surface portion 21 of the base 2 does not contain titanium.

[0033] For example, when the combination of sputtering and XPS described above is applied and it is determined that neither aluminum nor titanium is contained, it is determined that neither aluminum nor titanium is contained.

[0034] The substrate 2 may be mainly composed of hard particles made of WC, where the main component means 80% or more by mass.

[0035] In this case, the oxidation resistance of the surface portion 21 of the substrate 2 is likely to be improved, which tends to reduce the rate at which the substrate 2 wears after the coating layer 3 has worn away.

[0036] The coating layer 3 contains aluminum and titanium, and the surface portion 21 of the substrate 2 may contain aluminum and titanium.

[0037] In this case, the wear resistance, chipping resistance, and oxidation resistance of the coated tool 1 can be further improved.

[0038] The average thickness of the surface portion 21 of the substrate 2 may be greater than the average thickness of the coating layer 3 .

[0039] In this case, the residual stress in the surface portion 21 of the substrate 2 is likely to be further reduced regardless of the length or width of the surface portion 21 of the substrate 2. This makes it possible to further improve the adhesion between the substrate 2 and the coating layer 3 in the coated tool 1. As a result, it is possible to further improve the fracture resistance of the coated tool 1.

[0040] An example of a surface portion of the base body according to this embodiment will now be described with reference to Fig. 4. Fig. 4 is a cross-sectional view showing an example of a surface portion of the base body according to this embodiment.

[0041] 4, the surface portion 21 of the substrate 2 has a first portion 21a including the surface in contact with the coating layer 3, and a second portion 21b located on the opposite side of the first portion 21a from the surface in contact with the coating layer 3. As will be described later, the first portion 21a is a region where the average aluminum content is higher than the average titanium content. The second portion 21b is a region where the average aluminum content is lower than the average titanium content.

[0042] Next, an example of the distribution of atomic content in the coated tool according to this embodiment will be described with reference to Fig. 5 . Fig. 5 is a diagram showing an example of the distribution of atomic content in the coated tool according to this embodiment. Fig. 5 shows an example in which the coating layer 3 contains aluminum and titanium, and the surface portion 21 of the substrate 2 also contains aluminum and titanium. In Fig. 5 , the horizontal axis represents the distance from the surface of the coated tool 1 in the thickness direction of the coating layer 3, i.e., the position in the thickness direction of the coating layer 3. In Fig. 5 , the vertical axis represents the atomic content (atomic %).

[0043] 5, the average content of aluminum in the coating layer 3 is greater than the average content of titanium in the coating layer 3. The average content of atoms means the average value of the atomic contents measured at multiple positions in the thickness direction of the coated tool 1. For example, the coating layer 3 may be divided into five equal regions in the thickness direction of the coated tool 1, and the average value of the atomic contents measured in each region may be used as the "average content."

[0044] In this case, the formation of a complex oxide that is resistant to oxidation is easily promoted in the coating layer 3. As a result, the oxidation resistance and heat resistance of the coating layer 3 can be improved.

[0045] 5, the surface portion 21 of the substrate 2 includes a region in which the average aluminum content is lower than the average titanium content. The region in which the average aluminum content is lower than the average titanium content may exist, for example, in a range from a distance of D×0.8 to a distance of D×1.0, which is the thickness of the coating layer, from the interface between the substrate 2 and the coating layer 3 toward the center.

[0046] Depending on the measurement method, the atomic content of the substrate 2 and / or the atomic content of the coating layer 3 may not be evaluated using a straight line or a curve of a lower order. In such cases, the atomic content graph shown in Figure 5 may be evaluated using an approximation curve.

[0047] In this case, the toughness of the substrate 2 is likely to be improved, and as a result, the fracture resistance of the coated tool 1 can be improved.

[0048] 5, the average aluminum content in the first portion 21a is greater than the average aluminum content in the second portion 21b, and the average titanium content in the first portion 21a is greater than the average titanium content in the second portion 21b.

[0049] In this case, the hardness of the first portion 21a is likely to be improved by the diffusion of aluminum and titanium contained in the coating layer 3 from the coating layer 3 to the first portion 21a, which results in improved wear resistance of the coated tool 1. In addition, the oxidation resistance of the first portion 21a can also be improved.

[0050] 5, the average aluminum content in the first portion 21a is greater than the average titanium content in the first portion 21a, and the average aluminum content in the second portion 21b is less than the average titanium content in the second portion 21b.

[0051] The second portion 21b, in which the average aluminum content is lower than the average titanium content, is located on the side opposite to the surface in contact with the coating layer 3, relative to the first portion 21a, in which the average aluminum content is higher than the average titanium content. In this case, the toughness of the second portion 21b is likely to be improved. As a result, the fracture resistance of the coated tool 1 can be improved. Furthermore, the balance between the wear resistance and fracture resistance of the coated tool 1 can be improved.

[0052] As shown in Fig. 5, the region containing titanium in the surface portion 21 of the base 2 extends closer to the center portion 22 of the base 2 than the region containing aluminum in the surface portion 21 of the base 2. As shown in Fig. 5, this can be rephrased as "the surface portion 21 has a first region 21c containing aluminum and titanium, and a second region 21d which contains titanium but does not contain aluminum and is located closer to the center portion 22 than the first region 21c."

[0053] In this case, the toughness of the surface portion 21 of the substrate 2 is likely to be improved, and as a result, the chipping resistance of the coated tool 1 can be improved.

[0054] 5 , if the region of second portion 21b closer to first portion 21a is defined as the surface-side region, the region closer to center 22 than the surface-side region is defined as the intermediate region, and the region closer to center 22 than the intermediate region is defined as the central region, the rate of decrease in the aluminum content in the surface-side region is greater than the rate of decrease in the aluminum content in the intermediate region, and the rate of decrease in the aluminum content in the intermediate region is smaller than the rate of decrease in the aluminum content in the central region. Here, the rate of decrease may be the slope of the graph shown in FIG. 5 . Each of the surface-side region, intermediate region, and central region may have a thickness in the thickness direction that is equal to or greater than D×0.1.

[0055] As shown in Figure 5, if the portion of second portion 21b closer to first portion 21a is defined as the surface portion, the portion closer to center portion 22 than the surface portion is defined as the intermediate portion, and the portion closer to center portion 22 than the intermediate portion is defined as the central portion, the rate of decrease in the titanium content in the surface portion is greater than the rate of decrease in the titanium content in the intermediate portion, and the rate of decrease in the titanium content in the intermediate portion is smaller than the rate of decrease in the titanium content in the central portion. Here, the rate of decrease may be the slope of the graph shown in Figure 5. The surface portion, intermediate portion, and central portion may each have a thickness in the thickness direction that is equal to or greater than D x 0.1.

[0056] <Method for manufacturing the coated tool 1> Next, an example of a method for manufacturing the coated tool 1 according to this embodiment will be described. The method for manufacturing the coated tool 1 according to this embodiment is not limited to the following manufacturing method.

[0057] The coated tool 1 is manufactured by forming a coating layer 3 on a substrate 2. The coating layer 3 may be formed by, for example, a physical vapor deposition (PVD) method. For example, when the coating layer 3 is formed by using physical vapor deposition while the substrate 2 is held on the inner circumferential surface of the through hole 15, the coating layer 3 can be formed so as to cover the entire surface of the substrate 2 except for the inner circumferential surface of the through hole 15.

[0058] Examples of physical vapor deposition methods include ion plating methods such as arc ion plating (AIP) and sputtering. The arc ion plating method uses arc discharge in a vacuum atmosphere to evaporate a target metal, and nitrogen (N ２ ) gas, etc. to form a film of metal or metal nitride.

[0059] For example, when the coating layer 3 is formed on the substrate 2 by arc ion plating, the coated tool 1 can be produced by the following method.

[0060] As an example, a metal target of Ti, Al, or M, or a composite alloy target, or a sintered target is prepared, where M is at least one metal selected from Groups 4, 5, and 6 (excluding Cr) of the periodic table of elements, and Si.

[0061] Next, the target, which is the metal source, is evaporated and ionized by arc discharge or glow discharge. The ionized metal is then evaporated with nitrogen (N ２ ) gas and is deposited on the surface of the substrate 2. As a result, the coating layer 3 can be formed on the substrate 2.

[0062] Here, the plasma density and plasma energy of the ionized metal are increased in order to diffuse the aluminum and titanium contained in the coating layer 3 into the surface portion 21 of the substrate 2. Methods for increasing the plasma density and plasma energy of the ionized metal include, for example, setting the temperature of the substrate 2 to a temperature in the range of 550°C to 600°C, setting the gas pressure of nitrogen gas or the like to a pressure in the range of 2.0 Pa to 4.0 Pa, setting the distance between the target and the substrate 2 to a distance in the range of 50 mm to 200 mm, setting the bias voltage applied to the substrate 2 to a voltage in the range of 50 V to 100 V, forming a magnetic field linearly in the target direction, setting the distance between the cathodes to a distance in the range of 100 mm to 200 mm, and setting the magnetic flux density of the magnet to a magnetic flux density in the range of 20 mT to 80 mT.

[0063] <Cutting Tool> Next, a cutting tool including the above-described coated tool 1 will be described with reference to Fig. 6. Fig. 6 is a front view showing an example of a cutting tool according to this embodiment.

[0064] As shown in FIG. 6 , a cutting tool 100 according to this embodiment includes a coated tool 1 and a holder 70 for fixing the coated tool 1 .

[0065] The holder 70 is a rod-shaped member extending from a first end (the upper end in FIG. 6 ) to a second end (the lower end in FIG. 6 ). The holder 70 is made of, for example, steel or cast iron. Among these materials, steel, which has high toughness, may be used.

[0066] The holder 70 has a pocket 73 at the end on the first end side. The pocket 73 is a portion where the coated tool 1 is attached, and has a seating surface that intersects with the rotation direction of the workpiece and a constraint side surface that is inclined relative to the seating surface. The seating surface is provided with a screw hole into which a screw 75, which will be described later, is threaded.

[0067] The coated tool 1 is positioned in a pocket 73 of the holder 70 and attached to the holder 70 by a screw 75. That is, the screw 75 is inserted into the through hole 5 of the coated tool 1, and the tip of the screw 75 is inserted into a threaded hole formed in the seating surface of the pocket 73 to screw the threaded portions together. In this way, the coated tool 1 is attached to the holder 70 so that the cutting edge portion protrudes outward from the holder 70.

[0068] In this embodiment, a cutting tool 100 used for so-called turning is illustrated. Examples of turning include internal diameter machining, external diameter machining, and grooving. The cutting tool is not limited to that used for turning. For example, the coated tool 1 may be used as a cutting tool used for milling. Examples of cutting tools used for milling include milling cutters such as flat milling cutters, face milling cutters, side milling cutters, and groove milling cutters, and end mills such as single-blade end mills, multi-blade end mills, tapered-blade end mills, and ball end mills.

[0069] Examples of the present disclosure will be specifically described below, but the present disclosure is not limited to the examples shown below.

[0070] (Example) First, a coating layer was formed on a substrate by arc ion plating under the conditions shown in Table 1, and a coated tool including the substrate and the coating layer located thereon was produced. Here, a WC-based cemented carbide was used as the substrate. The film formation time was adjusted under various conditions so that the thickness of the coating layer formed on the substrate would be 2.0 μm. The average composition of the coating layer formed on the substrate is shown in Table 1.

[0071] Next, a photograph of a cross section including the substrate and the coating layer of the coated tool produced as an example was taken using a scanning transmission electron microscope. The interface between the substrate and the coating layer was identified from the photograph of the cross section including the substrate and the coating layer.

[0072] Next, the distribution of atomic content in the coated tool manufactured as an example was measured using a sputtering device and an XPS device. The analysis conditions using the XPS device are as follows: Device name: Quantera II manufactured by PHI X-ray source: Monochrome AlKα (200 μm 15 kV) Measurement area: Approximately 200 μmφ Pass energy: 224.0 eV Step size: 0.400 eV Sputtering conditions Ion species: Ar ＋ Acceleration voltage: 4 kV HP Sputtering rate: 15.41 nm / min (equivalent to the thickness of the ultra-hard material)

[0073] Fig. 7 is a diagram showing the distribution of atomic content in the coated tool according to Example Sample No. 1. In Fig. 7, the horizontal and vertical axes represent sputter thickness (nm) and atomic content (atomic %), respectively. The distribution of atomic aluminum and titanium content in the coated tool according to Example Sample No. 1 was measured.

[0074] 7, in the coated tool according to Example Sample No. 1, it was confirmed that the coating layer contained aluminum and titanium, and the surface portion of the substrate also contained aluminum and titanium. The thickness of the surface portion of the substrate was approximately 2500 nm.

[0075] 7, it was confirmed that the average aluminum content in the coating layer was greater than the average titanium content in the coating layer, and that the surface portion of the substrate included a region in which the average aluminum content was lower than the average titanium content.

[0076] As shown in FIG. 7 , it was confirmed that the average aluminum content in the first part was greater than the average aluminum content in the second part, the average titanium content in the first part was greater than the average titanium content in the second part, the average aluminum content in the first part was greater than the average titanium content in the first part, and the average aluminum content in the second part was smaller than the average titanium content in the second part.

[0077] As shown in FIG. 7, it was confirmed that the titanium-containing region in the surface portion extends further toward the center than the aluminum-containing region in the surface portion.

[0078] Among the examples, in at least Samples No. 1 to No. 7, the coated tool includes a substrate and a coating layer located on the substrate, the coating layer containing at least one of aluminum and titanium, the substrate has a surface portion including a surface in contact with the coating layer and a center portion located on the opposite side of the surface portion from the coating layer, and the surface portion contains at least one of aluminum and titanium.

[0079] Among the examples, at least in Samples No. 1 to No. 7, the substrate contains hard particles made of WC as a main component.

[0080] Among the examples, at least in Samples No. 1 to No. 6, the average thickness of the surface portion is greater than the average thickness of the coating layer.

[0081] Among the examples, in at least Samples No. 1 to No. 4 and No. 7, the coating layer contains aluminum and titanium, and the surface portion contains aluminum and titanium.

[0082] Among the examples, in at least Samples No. 1, No. 3, and No. 7, the average aluminum content in the coating layer is greater than the average titanium content in the coating layer.

[0083] Among the examples, at least in Samples No. 1, No. 2, and No. 4, the surface portion includes a region in which the average aluminum content is lower than the average titanium content.

[0084] Among the examples, at least in Sample No. 1, the surface portion has a first portion including the surface and a second portion located on the opposite side of the first portion from the surface side, and the average titanium content in the first portion is greater than the average titanium content in the second portion, the average aluminum content in the first portion is greater than the average titanium content in the first portion, and the average aluminum content in the second portion is less than the average titanium content in the second portion.

[0085] Among the Examples, in at least Samples No. 1, No. 2, and No. 4, the titanium-containing region in the surface portion extends closer to the center than the aluminum-containing region in the surface portion.

[0086] Similarly, the atomic content distribution of a conventional coated tool as a comparative example was measured. Figure 8 is a diagram showing the atomic content distribution of the coated tool according to comparative example sample No. 8. In Figure 8, the horizontal and vertical axes represent sputter thickness (nm) and atomic content (atomic %), respectively. The atomic content distributions of aluminum and titanium were measured in the coated tool according to the comparative example.

[0087] As shown in Fig. 8, in the coated tool according to Sample No. 8 of the comparative example, it was confirmed that the coating layer contained aluminum and titanium, but the substrate contained neither aluminum nor titanium.

[0088] Next, cutting tests were conducted on the coated tools of the example and the comparative example. The cutting test conditions are shown below. Cutting conditions Workpiece material: SCM420 Cutting speed: Vc = 120 m / min (low speed) and 200 m / min (high speed) Feed: f = 0.1 mm / rev Depth of cut: ae = 1.5 mm Cutting state: Wet Cutting tool shape: GBA43R300-030GM Evaluation method: Turning was performed for 120 minutes under the above conditions, and the wear width of the front flank after cutting was measured.

[0089] Table 2 shows the results of cutting tests on the coated tools according to Example Samples No. 1 to No. 7 and Comparative Samples No. 8 to No. 10. More specifically, Table 2 shows the wear width (mm) of the leading flank of the coated tools when low-speed and high-speed cutting was performed under the above-mentioned cutting conditions.

[0090] As shown in Table 2, the wear width of the front flank of the coated tools according to Samples No. 1 to No. 7 of the Examples was smaller than the wear width of the front flank of the coated tools according to Samples No. 8 to No. 10 of the Comparative Examples, in both low-speed cutting and high-speed cutting. Thus, it was confirmed that the wear resistance and fracture resistance of the coated tools according to Samples No. 1 to No. 7 of the Examples were improved compared to the coated tools according to Samples No. 8 to No. 10 of the Comparative Examples.

[0091] <Notes> (1): A coated tool comprising a base and a coating layer located on the base, wherein the coating layer contains at least one of aluminum and titanium, and the base has a surface portion including a surface in contact with the coating layer and a center portion located on the opposite side of the surface portion from the coating layer, wherein the surface portion contains at least one of aluminum and titanium. (2): A coated tool according to (1), wherein the base is mainly composed of hard particles made of WC. (3): A coated tool according to (1) or (2), wherein the average thickness of the surface portion is greater than the average thickness of the coating layer. (4): A coated tool according to any one of (1) to (3), wherein the coating layer contains aluminum and titanium, and the surface portion contains aluminum and titanium. (5): A coated tool according to (4), wherein the average aluminum content in the coating layer is greater than the average titanium content in the coating layer. (6): The coated tool according to (4) or (5), wherein the surface portion includes a region in which the average aluminum content is lower than the average titanium content. (7): The coated tool according to any one of (4) to (6), wherein the surface portion has: a first portion including the surface; and a second portion located on the opposite side of the first portion from the surface side, wherein the average titanium content in the first portion is higher than the average titanium content in the second portion, the average aluminum content in the first portion is higher than the average titanium content in the first portion, and the average aluminum content in the second portion is lower than the average titanium content in the second portion. (8): The coated tool according to any one of (4) to (7), wherein the region containing titanium in the surface portion extends closer to the center than the region containing aluminum in the surface portion. (9): A cutting tool comprising: a rod-shaped holder having a pocket at an end; and the coated tool according to any one of (1) to (8), located in the pocket.

[0092] Further advantages and / or modifications may readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.

[0093] DESCRIPTION OF SYMBOLS 1 Coated tool 11 Insert 15 Through hole 2 Base body 21 Surface portion 21a First portion 21b Second portion 21c First region 21d Second region 22 Center portion 3 Coating layer 70 Holder 73 Pocket 75 Screw 100 Cutting tool D Thickness of coating layer

Claims

1. A coated tool comprising: a substrate; and a coating layer located on the substrate, wherein the coating layer contains at least one of aluminum and titanium; the substrate has a surface portion including a surface in contact with the coating layer; and a center portion located on the opposite side of the surface portion from the coating layer, wherein the surface portion contains at least one of aluminum and titanium.

2. The coated tool according to claim 1, wherein the substrate is mainly composed of hard particles made of WC.

3. The coated tool according to claim 1 or 2, wherein the average thickness of the surface portion is greater than the average thickness of the coating layer.

4. The coated tool according to any one of claims 1 to 3, wherein the coating layer contains aluminum and titanium, and the surface portion contains aluminum and titanium.

5. The coated tool according to claim 4, wherein the average aluminum content in the coating layer is greater than the average titanium content in the coating layer.

6. The coated tool according to claim 4 or 5, wherein the surface portion includes a region in which the average aluminum content is lower than the average titanium content.

7. A coated tool according to any one of claims 4 to 6, wherein the surface portion has a first portion including the surface and a second portion located on the opposite side of the first portion to the surface, the average titanium content in the first portion being greater than the average titanium content in the second portion, the average aluminum content in the first portion being greater than the average titanium content in the first portion, and the average aluminum content in the second portion being less than the average titanium content in the second portion.

8. A coated tool according to any one of claims 4 to 7, wherein the titanium-containing region in the surface portion extends closer to the center than the aluminum-containing region in the surface portion.

9. A cutting tool comprising: a rod-shaped holder having a pocket at an end thereof; and a coated tool according to any one of claims 1 to 8 positioned in said pocket.

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