Coated and cutting tools

Abstract

A coated tool according to the present disclosure comprises: a substrate; and a coating layer positioned on the substrate and comprising cubic crystals. An X-ray diffraction spectrum, measured for the coating layer which has been held in a non-oxidizing atmosphere at a temperature of 1200°C for 0.5 hours, satisfies the relationship Ih(100) / Ih(002) ≤ 0.9. Ih(100) is the intensity of a diffraction peak corresponding to a (100) face of a hexagonal crystal formed in the coating layer. Ih(002) is the intensity of a diffraction peak corresponding to a (002) face of the hexagonal crystal.

Description

[Technical Field]

[0001] The present disclosure relates to coated tools and cutting tools. [Background technology]

[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. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-3284 Summary of the Invention

[0004] A coated tool according to one embodiment of the present disclosure includes a substrate and a coating layer formed on the substrate and composed of a cubic crystal. The X-ray diffraction spectrum of the coating layer measured after being held at 1200°C for 0.5 hours in a non-oxidizing atmosphere satisfies the relationship Ih(100) / Ih(002)≦0.9. Ih(100) is the intensity of the diffraction peak corresponding to the (100) plane of the hexagonal crystal formed in the coating layer. Ih(002) is the intensity of the diffraction peak corresponding to the (002) plane of the hexagonal crystal. [Brief explanation of the drawings]

[0005] [Figure 1] FIG. 1 is a perspective view showing an example of a coated tool according to an embodiment. [Figure 2] FIG. 2 is a side cross-sectional view showing an example of a coated tool according to an embodiment. [Figure 3] FIG. 3 is a diagram schematically showing an example of an X-ray diffraction spectrum measured for the coating layer according to the embodiment. [Figure 4] FIG. 4 is a cross-sectional view showing an example of a coating layer according to an embodiment. [Figure 5] FIG. 5 is a cross-sectional view showing an example of a Ta-containing laminate structure and a Mo-containing laminate structure that constitute a coating layer according to an embodiment. [Figure 6] FIG. 6 is a cross-sectional view showing an example of a first compound layer and a second compound layer constituting a Ta-containing laminated structure. [Figure 7] FIG. 7 is a cross-sectional view showing an example of the third compound layer and the fourth compound layer constituting the Mo-containing laminated structure. [Figure 8] FIG. 8 is a diagram schematically illustrating an example of a film forming apparatus for forming a coating layer on a substrate. [Figure 9] FIG. 9 is a front view showing an example of a cutting tool according to an embodiment. [Figure 10] FIG. 10 is a table showing the manufacturing conditions for the coating layer formed on the substrate. [Figure 11] FIG. 11 is a table showing the configuration of the coating layer formed on the substrate. [Figure 12A] FIG. 12A is a diagram showing an X-ray diffraction spectrum measured on the coating layer of the coated tool of Sample No. 1 after heat treatment. [Figure 12B] FIG. 12B is a diagram showing an X-ray diffraction spectrum measured on the coating layer of the coated tool of Sample No. 2 after heat treatment. [Figure 12C] FIG. 12C is a diagram showing an X-ray diffraction spectrum measured on the coating layer of the coated tool of Sample No. 3 after heat treatment. [Figure 12D] FIG. 12D is a diagram showing an X-ray diffraction spectrum measured on the coating layer of the coated tool of Sample No. 4 after heat treatment. [Figure 13] FIG. 13 is a table showing the results of X-ray diffraction spectrum measurements and cutting tests for the coated tools of Samples No. 1 to No. 4. DETAILED DESCRIPTION OF THE INVENTION

[0006] Hereinafter, modes for carrying out the coated tool and 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 cutting tool according to the present disclosure are not limited to these embodiments. The embodiments can be appropriately combined within the scope of not causing any contradiction in the processing content. In the following embodiments, the same components are designated by the same reference numerals, and redundant explanations will be omitted.

[0007] In the following embodiments, expressions such as "constant," "orthogonal," "perpendicular," or "parallel" may be used, but these expressions do not necessarily mean "constant," "orthogonal," "perpendicular," or "parallel" in a strict sense. In other words, the above expressions allow for deviations due to, for example, manufacturing precision or installation precision.

[0008] 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.

[0009] The above-mentioned prior art has room for further improvement in terms of extending the tool life.

[0010] Therefore, there is a need to develop a technology that can overcome the above-mentioned problems and extend the tool life.

[0011] <Coated tools> Fig. 1 is a perspective view showing an example of a coated tool according to an embodiment. Fig. 2 is a side cross-sectional view showing an example of a coated tool 1 according to an embodiment. As shown in Fig. 1, the coated tool 1 according to the embodiment has a tip body 2.

[0012] (Chip body 2) The chip body 2 has, for example, a hexahedral shape in which the upper and lower surfaces (surfaces intersecting with the Z axis shown in FIG. 1) are parallelogram-shaped.

[0013] One corner of the insert body 2 functions as a cutting edge portion. The cutting edge portion has a first surface (for example, an upper surface) and a second surface (for example, a side surface) connected to the first surface. In the embodiment, the first surface functions as a "rake surface" that scoops up chips generated by cutting, and the second surface functions as a "flank surface." A cutting edge is located on at least a portion of the ridge where the first and second surfaces intersect, and the coated tool 1 cuts the workpiece by applying this cutting edge to the workpiece.

[0014] A through-hole 5 that passes through the tip body 2 from top to bottom is located in the center of the tip body 2. A screw 75 is inserted into the through-hole 5 to attach the coated tool 1 to a holder 70 (described later) (see FIG. 9).

[0015] As shown in FIG. 2, the chip body 2 has a base 10 and a coating layer 20.

[0016] (Base 10) The substrate 10 is formed of, for example, a cemented carbide. The cemented carbide contains W (tungsten), specifically WC (tungsten carbide). The cemented carbide may also contain Ni (nickel) or Co (cobalt). Specifically, the substrate 10 is made of a WC-based cemented carbide containing WC particles as the hard phase component and Co as the main component of the binder phase.

[0017] The substrate 10 may be formed of a cermet. The cermet contains, for example, Ti (titanium), specifically, TiC (titanium carbide) or TiN (titanium nitride). The cermet may also contain Ni or Co.

[0018] The substrate 10 may be formed of a cubic boron nitride sintered body containing cubic boron nitride (cBN) particles. The substrate 10 is not limited to cubic boron nitride (cBN) particles, but may also contain particles of hexagonal boron nitride (hBN), rhombohedral boron nitride (rBN), wurtzite boron nitride (wBN), or the like.

[0019] The substrate 10 may be formed of ceramics. The ceramics may contain, for example, aluminum oxide (Al2O3), such as κ-Al2O3 and α-Al2O3. The ceramics may contain other elements in addition to aluminum oxide. For example, the ceramics may contain, in addition to aluminum oxide, at least one of magnesium (Mg), calcium (Ca), strontium (Sr), silicon (Si), and elements from Group 3 of the periodic table.

[0020] (Coating layer 20) The coating layer 20 is applied to the substrate 10 for the purpose of improving the abrasion resistance, heat resistance, etc. of the substrate 10. In the example of FIG. 2, the coating layer 20 covers the entire substrate 10. The coating layer 20 needs to be located at least on the substrate 10. When the coating layer 20 is located on the first surface (here, the top surface) of the substrate 10, the abrasion resistance and heat resistance of the first surface are high. When the coating layer 20 is located on the second surface (here, the side surface) of the substrate 10, the abrasion resistance and heat resistance of the second surface are high.

[0021] Specific characteristics of the coating layer 20 will now be described with reference to FIG. 3. FIG. 3 is a diagram schematically illustrating an example of an X-ray diffraction spectrum measured for the coating layer 20 according to the embodiment. The coating layer 20 according to the embodiment is made of cubic crystals at temperatures from room temperature to 1000°C. The coated tool 1 according to the embodiment is subjected to heat treatment in which the coating layer 20 is held at 1200°C for 0.5 hours in a non-oxidizing atmosphere. For example, a closed heating furnace (atmospheric furnace) can be used for the heat treatment. The non-oxidizing atmosphere can be, for example, a neutral gas such as nitrogen or hydrogen, or an inert gas such as helium or argon.

[0022] Such heat treatment causes a phase transformation from cubic to hexagonal crystals that constitute the coating layer 20 according to the embodiment. That is, the coating layer 20 after the heat treatment contains not only cubic crystals but also hexagonal crystals.

[0023] Next, an X-ray diffraction spectrum of the heat-treated coating layer 20 is measured using an X-ray diffractometer (XRD). As shown in Figure 3, the X-ray diffraction spectrum measured after the heat treatment shows various diffraction peaks, such as a diffraction peak corresponding to the (111) plane of the cubic crystal, a diffraction peak corresponding to the (200) plane of the cubic crystal, a diffraction peak corresponding to the (100) plane of the hexagonal crystal, and a diffraction peak corresponding to the (002) plane of the hexagonal crystal. In Figure 3, the diffraction peaks corresponding to the (111) plane of the cubic crystal, the diffraction peak corresponding to the (200) plane of the cubic crystal, the diffraction peak corresponding to the (100) plane of the hexagonal crystal, and the diffraction peak corresponding to the (002) plane of the hexagonal crystal are indicated as c(111), c(200), h(100), and h(002), respectively.

[0024] For the coating layer 20 according to the embodiment, the X-ray diffraction spectrum measured for the heat-treated coating layer 20 satisfies the relationship Ih(100) / Ih(002)≦0.9, where Ih(100) is the intensity of the diffraction peak corresponding to the (100) plane of the hexagonal crystal formed in the coating layer 20, and Ih(002) is the intensity of the diffraction peak corresponding to the (002) plane of the hexagonal crystal.

[0025] If the X-ray diffraction spectrum measured for the coating layer 20 after heat treatment satisfies the relationship Ih(100) / Ih(002)≦0.9, then the proportion of hexagonal crystals formed in the coating layer 20 that are oriented so that the (002) plane of the hexagonal crystals is parallel to the surface of the substrate 10 on which the coating layer 20 is provided (the c-axis of the hexagonal crystals is perpendicular to the surface of the substrate 10) (hereinafter referred to as “hexagonal crystals of the first orientation”) is greater than the proportion of hexagonal crystals that are oriented so that the (100) plane of the hexagonal crystals is parallel to the surface of the substrate 10 (the c-axis of the hexagonal crystals is parallel to the surface of the substrate 10) (hereinafter referred to as “hexagonal crystals of the second orientation”).

[0026] Hexagonal crystals with a first orientation are more likely to slip along the (002) plane, while hexagonal crystals with a second orientation are more likely to slip along the (100) plane. Here, the (002) plane of a hexagonal crystal is more likely to slip between planes than the (100) plane of a hexagonal crystal. Therefore, when the proportion of hexagonal crystals with a first orientation is greater than the proportion of hexagonal crystals with a second orientation, slip along the (002) plane is more likely to occur. As a result, damage caused by welding of the workpiece (such as film peeling due to the detachment of welded portions and damage such as chipping) can be minimized, and the welding resistance and chipping resistance of the coating layer 20 can be improved.

[0027] When a workpiece is cut using the coated tool 1 according to the embodiment, the distortion of the hexagonal crystals in the first orientation is thought to be smaller than the distortion of the hexagonal crystals in the second orientation. Therefore, when the proportion of the hexagonal crystals in the first orientation is larger than the proportion of the hexagonal crystals in the second orientation, it is thought that the decrease in hardness of the coating layer 20 can be reduced. As a result, it is thought that the wear resistance of the coating layer 20 can be improved.

[0028] In this way, when the X-ray diffraction spectrum measured on the coating layer 20 after the heat treatment satisfies the relationship Ih(100) / Ih(002)≦0.9, the life of the coated tool 1 can be extended.

[0029] During high-speed machining, the temperature of the coated tool 1 reaches approximately 1200°C. Therefore, heat treatment in which the coating layer 20 is maintained at 1200°C for 0.5 hours in a non-oxidizing atmosphere is considered to correspond to high-speed machining (machining at a cutting speed of approximately 200 m / min) using the coated tool 1. During high-speed machining, when the temperature of the cubic coating layer 20 rises to approximately 1200°C, hexagonal crystals are generated in the coating layer 20. Generally, an increase in the proportion of hexagonal crystals tends to decrease the hardness and wear resistance of the coating layer. As a result, the life of the coated tool during high-speed machining tends to be shortened. However, in the coated tool 1 according to the embodiment, the X-ray diffraction spectrum measured for the heat-treated coating layer 20 satisfies the relationship Ih(100) / Ih(002)≦0.9. This reduces the deterioration in wear resistance of the coating layer 20 during high-speed machining, and improves the adhesion resistance and chipping resistance of the coating layer 20 to the workpiece.

[0030] On the other hand, in low-speed machining, the temperature of the coated tool 1 is approximately from room temperature to 1000°C. In this case, since the coating layer 20 is made of cubic crystals, the hardness and wear resistance of the coating layer 20 are maintained. Furthermore, as described below, the hardness and toughness of the coating layer 20 can be improved by configuring the coating layer 20 so that the X-ray diffraction spectrum measured on the coating layer 20 after heat treatment satisfies the relationship Ih(100) / Ih(002)≦0.9. As a result, the wear resistance of the coating layer 20 can be improved in low-speed machining.

[0031] Thus, when the X-ray diffraction spectrum measured on the coating layer 20 after heat treatment satisfies the relationship Ih(100) / Ih(002)≦0.9, the life of the coated tool 1 can be extended in both low-speed and high-speed machining.

[0032] The X-ray diffraction spectrum measured for the coating layer 20 after the heat treatment may satisfy the relationship Ih(100) / Ih(002)≦0.3. In this case, the proportion of hexagonal crystals with the first orientation can be further increased. As a result, the life of the coated tool 1 can be further extended.

[0033] Here, a specific configuration of the coating layer 20 in which the X-ray diffraction spectrum measured for the heat-treated coating layer 20 satisfies the relationship Ih(100) / Ih(002)≦0.9 will be described with reference to FIGS. 4, 5, 6, and 7. FIG. 4 is a cross-sectional view showing an example of the coating layer 20 according to the embodiment. FIG. 5 is a cross-sectional view showing an example of the Ta-containing laminated structure and the Mo-containing laminated structure constituting the coating layer 20 according to the embodiment. FIG. 6 is a cross-sectional view showing an example of the first compound layer and the second compound layer constituting the Ta-containing laminated structure. FIG. 7 is a cross-sectional view showing an example of the third compound layer and the fourth compound layer constituting the Mo-containing laminated structure.

[0034] 4, the coating layer 20 includes a plurality of Ta-containing laminated structures 22 and a plurality of Mo-containing laminated structures 23 located on the intermediate layer 21. Each of the plurality of Ta-containing laminated structures 22 is a laminated structure containing at least Ta. Each of the plurality of Mo-containing laminated structures 23 is a laminated structure containing at least Mo.

[0035] As shown in FIG. 4, a plurality of Ta-containing stacked structures 22 and a plurality of Mo-containing stacked structures 23 may be stacked alternately in the coating layer 20.

[0036] In this case, the residual stress between the Ta-containing laminate structure 22 and the Mo-containing laminate structure 23 can be reduced. This can reduce peeling or cracking between the Ta-containing laminate structure 22 and the Mo-containing laminate structure 23. Furthermore, the effects of the Ta-containing laminate structure 22 and the Mo-containing laminate structure 23, which will be described later, can be improved. As a result, the life of the coated tool 1 can be extended.

[0037] The average thickness of each of the plurality of Ta-containing stacked structures 22 and the plurality of Mo-containing stacked structures 23 may be 300 nm or more and 500 nm or less.

[0038] In this case, the residual stress between the Ta-containing laminate structure 22 and the Mo-containing laminate structure 23 can be reduced. This can reduce peeling or cracking between the Ta-containing laminate structure 22 and the Mo-containing laminate structure 23. Furthermore, the effects of the Ta-containing laminate structure 22 and the Mo-containing laminate structure 23, which will be described later, can be improved. As a result, the life of the coated tool 1 can be extended.

[0039] (Middle class 21) An intermediate layer 21 may be located between the base 10 and the coating layer 20. Specifically, the intermediate layer 21 has one surface (here, the lower surface) in contact with the upper surface of the base 10, and the other surface (here, the upper surface) in contact with the lower surface of the coating layer 20 (for example, the Ta-containing stacked structure 22).

[0040] The intermediate layer 21 has higher adhesion to the substrate 10 than the coating layer 20. Examples of metal elements having such properties include Zr, Hf, V, Nb, Ta, Cr, Mo, W, Al, Si, Y, and Ti. The intermediate layer 21 contains at least one of the above metal elements. For example, the intermediate layer 21 may contain Ti. Si is a metalloid element, and in this specification, metalloid elements are also included in the category of metal elements.

[0041] When intermediate layer 21 contains Ti, the Ti content in intermediate layer 21 may be 1.5 atomic % or more. For example, the Ti content in intermediate layer 21 may be 2.0 atomic % or more.

[0042] Intermediate layer 21 may contain components other than the above metal elements (Zr, Hf, V, Nb, Ta, Cr, Mo, W, Al, Si, Y, and Ti). However, from the viewpoint of adhesion to substrate 10, intermediate layer 21 may contain the above metal elements in a total amount of at least 95 atomic % or more. Intermediate layer 21 may contain the above metal elements in a total amount of 98 atomic % or more. The proportion of the metal components in intermediate layer 21 can be determined, for example, by analysis using an EDS (energy dispersive X-ray spectroscope) attached to a STEM (scanning transmission electron microscope).

[0043] In this way, by providing the intermediate layer 21, which has higher wettability with the substrate 10 than the coating layer 20, between the substrate 10 and the coating layer 20, it is possible to improve the adhesion between the substrate 10 and the coating layer 20. Since the intermediate layer 21 also has high adhesion with the coating layer 20, peeling of the coating layer 20 from the intermediate layer 21 is unlikely to occur.

[0044] The thickness of the intermediate layer 21 may be, for example, not less than 0.1 nm and less than 20 nm.

[0045] (Ta-containing laminated structure 22) 5, each of the multiple Ta-containing stacked structures 22 includes a first compound layer 22a and a second compound layer 22b. The first compound layer 22a contains Ta at a first composition ratio. The second compound layer 22b contains Ta at a second composition ratio different from the first composition ratio. Note that one of the first composition ratio and the second composition ratio may be zero.

[0046] In this way, each of the plurality of Ta-containing laminate structures 22 includes the first compound layer 22a containing Ta at a first composition ratio and the second compound layer 22b containing Ta at a second composition ratio different from the first composition ratio, thereby improving the thermal shock resistance, oxidation resistance, and high-temperature hardness of the coating layer 20. As a result, the life of the coated tool 1 can be extended.

[0047] Each of the first compound layer 22a and the second compound layer 22b may contain Al, Ti, and Ta. In this case, the content Al(1) of Al contained in the first compound layer 22a, the content Ti(1) of Ti contained in the first compound layer 22a, the content Ta(1) of Ta contained in the first compound layer 22a, the content Al(2) of Al contained in the second compound layer 22b, the content Ti(2) of Ti contained in the second compound layer 22b, and the content Ta(2) of Ta contained in the second compound layer 22b are expressed as Al(1) <Al(2)、Ti(1)<Ti(2)、およびTa(1)> There may be a relationship of Ta(2), which may be 0.

[0048] Al(1), Ti(1), Ta(1), Al(2), Ti(2), and Ta(2) are Al(1) <Al(2)、Ti(1)<Ti(2)、およびTa(1)> When the relationship Ta(2) is satisfied, the residual stress between the first compound layer 22a and the second compound layer 22b can be reduced while maintaining the hardness and adhesion of the first compound layer 22a and the second compound layer 22b. This reduces peeling or cracking between the first compound layer 22a and the second compound layer 22b and improves the strength of the coating layer 20. As a result, the life of the coated tool 1 can be extended.

[0049] Each of the first compound layer 22a and the second compound layer 22b is a compound represented by the formula: (Al a Ti b Ta c )N···(1) (wherein a, b, and c satisfy the relationships 0.35≦a≦0.65, 0.3≦b≦0.5, 0.02≦c≦0.2, and a+b+c=1) The Ta-containing compound may be represented by the formula:

[0050] When a satisfies the relationship 0.35≦a≦0.65, the hardness and wear resistance of the coating layer 20 can be maintained. When b and c satisfy the relationships 0.3≦b≦0.5 and 0.02≦c≦0.2, the oxidation resistance of the coating layer 20 can be maintained and the strength of the coating layer 20 at high temperatures can be improved. As a result, the life of the coated tool 1 can be extended.

[0051] 6, the c of the Ta-containing compound contained in the first compound layer 22a may vary continuously in the thickness direction of the first compound layer 22a. The c of the Ta-containing compound contained in the second compound layer 22b may vary continuously in the thickness direction of the second compound layer 22b. For example, as shown in FIG. 6, the c of the Ta-containing compound contained in the first compound layer 22a may be maximum near the center of the distance in the thickness direction of the first compound layer 22a. The c of the Ta-containing compound contained in the second compound layer 22b may be minimum near the center of the distance in the thickness direction of the second compound layer 22b.

[0052] In this case, the residual stress between the first compound layer 22 a and the second compound layer 22 b can be further reduced, thereby reducing peeling or cracking between the first compound layer 22 a and the second compound layer 22 b, and as a result, the life of the coated tool 1 can be extended.

[0053] (Mo-containing laminated structure 23) 5, each of the multiple Mo-containing stacked structures 23 includes a third compound layer 23a and a fourth compound layer 23b. The third compound layer 23a contains Mo at a third composition ratio. The fourth compound layer 23b contains Mo at a fourth composition ratio different from the third composition ratio. One of the third composition ratio and the fourth composition ratio may be zero.

[0054] In this way, each of the plurality of Mo-containing laminate structures 23 includes the third compound layer 23a containing Mo at a third composition ratio and the fourth compound layer 23b containing Mo at a fourth composition ratio different from the third composition ratio, thereby improving the toughness and strength of the coating layer 20. Furthermore, the lubricity of the coating layer 20 can be maintained even at high temperatures. As a result, the life of the coated tool 1 can be extended.

[0055] Each of the third compound layer 23a and the fourth compound layer 23b may contain Al, Cr, and Mo. In this case, the content Al(3) of Al contained in the third compound layer 23a, the content Cr(3) of Cr contained in the third compound layer 23a, the content Mo(3) of Mo contained in the third compound layer 23a, the content Al(4) of Al contained in the fourth compound layer 23b, the content Cr(4) of Cr contained in the fourth compound layer 23b, and the content Mo(4) of Mo contained in the fourth compound layer 23b are the same as Al(3).<Al(4)、Cr(3)> Cr(4) and Mo(3)>Mo(4). Mo(4) can be 0.

[0056] Al(3), Cr(3), Mo(3), Al(4), Cr(4), and Mo(4) are Al(3)<Al(4)、Cr(3)> When the relationship between Cr(4) and Mo(3) > Mo(4) is satisfied, the residual stress between the third compound layer 23a and the fourth compound layer 23b can be reduced. This reduces peeling or cracking between the third compound layer 23a and the fourth compound layer 23b. Furthermore, the lubricity of the coating layer 20 can be maintained even at high temperatures, and the thermal shock resistance, strength, oxidation resistance, and hardness at high temperatures of the coating layer 20 can be further improved. As a result, the life of the coated tool 1 can be extended.

[0057] Each of the third compound layer 23a and the fourth compound layer 23b is a compound represented by the formula: (Al d Cr e Si f Mo g )N···(2) (wherein d, e, f, and g satisfy the relationships 0.35≦d≦0.65, 0.2≦e≦0.45, 0.03≦f≦0.15, 0.02≦g≦0.2, and d+e+f+g=1) The Mo-containing compound may be represented by the formula:

[0058] When d satisfies the relationship 0.35≦d≦0.65, the hardness and wear resistance of the coating layer 20 can be maintained. When e, f, and g satisfy the relationships 0.2≦e≦0.45, 0.03≦f≦0.15, and 0.02≦g≦0.2, the lubricity of the coating layer 20 at high temperatures can be maintained and the thermal shock resistance, strength, and oxidation resistance of the coating layer 20 can be improved. As a result, the life of the coated tool 1 can be extended.

[0059] 7, the g of the Mo-containing compound contained in the third compound layer 23a may vary continuously in the thickness direction of the third compound layer 23a. The g of the Mo-containing compound contained in the fourth compound layer 23b may vary continuously in the thickness direction of the fourth compound layer 23b. For example, as shown in FIG. 7, the g of the Mo-containing compound contained in the third compound layer 23a may be maximum near the center of the distance in the thickness direction of the third compound layer 23a. The g of the Mo-containing compound contained in the fourth compound layer 23b may be minimum near the center of the distance in the thickness direction of the fourth compound layer 23b.

[0060] In this case, the residual stress between the third compound layer 23 a and the fourth compound layer 23 b can be further reduced, thereby reducing peeling or cracking between the third compound layer 23 a and the fourth compound layer 23 b, and as a result, the life of the coated tool 1 can be extended.

[0061] The first compound layer 22a, the second compound layer 22b, the third compound layer 23a, and the fourth compound layer 23b may have an average thickness of 3 nm or more and 15 nm or less.

[0062] In this case, the Ta-containing laminate structure 22 including the first compound layer 22a and the second compound layer 22b is a laminate structure of multiple layers having a nanoscale thickness. The Mo-containing laminate structure 23 including the third compound layer 23a and the fourth compound layer 23b is a laminate structure of multiple layers having a nanoscale thickness. This improves the strength of the coating layer 20 against external forces. It also improves the oxidation resistance and high-temperature hardness of the coating layer 20. As a result, the life of the coated tool 1 can be extended.

[0063] <Method of manufacturing coated tools> Next, an example of a method for manufacturing the coated tool 1 according to the embodiment will be described with reference to Fig. 8. Fig. 8 is a diagram schematically showing an example of a film-forming apparatus for forming a coating layer on a substrate. Note that the method for manufacturing the coated tool 1 is not limited to the method described below.

[0064] First, a substrate 10 having the shape of the coated tool 1 is prepared using a conventionally known method. Next, a coating layer 20 is formed on the surface of the substrate 10. The coating layer 20 can be formed by, for example, a physical vapor deposition (PVD) method such as an ion plating method or a sputtering method. As an example, when the coating layer 20 is formed by the ion plating method, an arc ion plating film formation apparatus (hereinafter referred to as an AIP apparatus) 1000 as shown in FIG. 8 can be used.

[0065] 8, an AIP apparatus 1000 introduces a gas such as N2 or Ar into a vacuum chamber 101 through a gas inlet 102, and generates a gas plasma by applying a high voltage between a cathode electrode 103 and an anode electrode 104 disposed in the AIP apparatus 1000. This plasma evaporates and ionizes the desired metal or ceramic from a target 105, generating high-energy metal or ceramic ions. This ionized metal or ceramic is then deposited on the surface of a substrate 10 as a sample, thereby forming a coating layer 20 on the surface of the substrate 10.

[0066] As shown in Fig. 8, a plurality of substrates 10 may be set in a tower 107 and placed on a sample support stage 106. A plurality of sample support stages 106 (two sets in the figure) may be placed on a table (not shown). As shown in Fig. 8, a heater 108 for heating the substrates 10, a gas outlet 109 for discharging gas out of the system, and a bias power supply 110 for applying a bias voltage to the substrates 10 are provided.

[0067] Examples of the target 105 include metal targets each containing independently metal tantalum (Ta), metal molybdenum (Mo), and one or more metals selected from the group 5 or 6 elements of the periodic table, Si, Y, and Ce; alloy targets made by combining these; and mixture targets made of powders or sintered bodies of carbides, nitrides, or borides of these metals.

[0068] Using the target 105, a metal source is evaporated by arc discharge or glow discharge, and the metal of the metal source is ionized while reacting with nitrogen (N2) gas as a nitrogen source, methane (CH4) / acetylene (C2H2) gas as a carbon source, or oxygen (O2) gas, thereby depositing a coating layer 20 on the surface of the substrate 10.

[0069] At this time, the sample support stage 106 is controlled so that the distance from the position of the target 105 to the position of the substrate 10 is 160 mm or more, preferably 260 mm or more. A large number of highly linear magnetic field lines are generated from the center of the surface of the target 105 toward the substrate 10, and the magnetic flux density near the substrate 10 is set to 0.2 to 0.8 mT (millitesla).

[0070] Nitrogen gas may be introduced into the AIP device 1000 as a reactive gas, and the atmospheric pressure may be set to 2 to 10 Pa. The temperature of the substrate 10 is maintained at 300 to 500°C. A bias voltage of -50 to -200 V is applied to the substrate 10, and an arc discharge of 80 to 200 A is generated between the target 105 (cathode electrode 103) and the anode electrode 104. Metal is vapor-deposited onto the substrate 10 while the substrate 10 is rotated and revolved.

[0071] The magnetic flux density near the substrate 10 can be controlled, for example, by placing an electromagnetic coil or permanent magnet, which is a magnetic field generating source, around the target 105, by placing a permanent magnet inside the AIP device 1000, for example, in the center, or by adjusting the position of an adjacent target 105.

[0072] The magnetic force is calculated by measuring the magnetic flux density at the position of the substrate 10 using a magnetic flux density meter. The magnetic flux density is expressed in units of mT (millitesla). Here, the distance from the position of the target 105 to the position of the substrate 10 represents the distance measured at the position where the substrate 10 is closest to the target 105 and the distance where the substrate 10 is farthest from the target 105.

[0073] During film formation, when the rotation speed of the sample is defined as the period in which the substrate 10 approaches the target 105 most closely at each position on the substrate 10 as shown in Fig. 8, adjusting the rotation speed can adjust the period of the difference in composition between heavy metals and light metals in the thickness direction of the coating layer 20. Specifically, the rotation speed of the substrate 10 and the sample support 106 may be adjusted so that the period is 2 to 20 rpm (revolutions per minute).

[0074] During film formation, the tower 107 may rotate while the sample support stages 106 on which the substrates 10 are placed rotate, and the table may be rotated so that the sample support stages 106 revolve. By adjusting the timing of such revolutions, the thickness of each compound layer constituting the Ta-containing laminate structure 22 and the Mo-containing laminate structure 23 can be controlled.

[0075] By applying a pulsed bias voltage, it is possible to adjust the time or distance that metal ions travel from the target 105 to the substrate 10. This makes it possible to differentiate the composition of heavy metal components and light metal components during film formation.

[0076] For example, when the base 10 is positioned so that it is close to and facing the target 105, heavy metal components from the target 105 fly toward the base 10 in a straight line, and more heavy metals than light metals are deposited on the base 10. On the other hand, when the base 10 is positioned so that it is far from and not facing the target 105, the light metal components wrap around and deposit on the base 10, and it is thought that the amount of deposition of heavy metal components will decrease. In this case, by increasing the distance from the position of the target 105 to the position of the base 10 and maintaining a certain level of magnetic flux density near the base 10, it is thought that the wraparound of the light metal components will be promoted and the composition difference between the heavy metal components and the light metal components will increase.

[0077] <Cutting tools> Next, the configuration of a cutting tool including the above-described coated tool 1 will be described with reference to Fig. 9. Fig. 9 is a front view showing an example of a cutting tool according to an embodiment.

[0078] As shown in FIG. 9, a cutting tool 100 according to the embodiment includes a coated tool 1 and a holder 70 for fixing the coated tool 1.

[0079] The holder 70 is a rod-shaped member extending from a first end (the upper end in FIG. 9) to a second end (the lower end in FIG. 9). The holder 70 is made of, for example, steel or cast iron. Of these materials, steel, which has particularly high toughness, may be used.

[0080] 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.

[0081] 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 3 protrudes outward from the holder 70.

[0082] In the embodiment, a cutting tool used for so-called turning is exemplified. 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-flute end mills, multi-flute end mills, tapered-flute end mills, and ball end mills. [Example]

[0083] Hereinafter, examples of the present disclosure will be specifically described with reference to Figures 10 to 13. The present disclosure is not limited to the examples shown below.

[0084] Figure 10 is a table showing the manufacturing conditions for the coating layer formed on the substrate. Figure 11 is a table showing the configuration of the coating layer formed on the substrate.

[0085] Coated tools (Samples No. 1 to No. 4) were fabricated by forming a coating layer on a substrate made of a WC-based cemented carbide using an AIP apparatus as shown in Figure 8 under the manufacturing conditions shown in Figure 10. That is, the coating layer was formed on the surface of the substrate under the conditions of arc current (mA), target composition, distance between the target and the substrate (mm), magnetic flux density (mT) near the substrate, and rotation speed (rpm) of the sample holder as shown in Figure 10. The distance between the target and the substrate (mm) varied within the range of values ​​shown in Figure 10 depending on the rotation of the sample holder. Correspondingly, the magnetic flux density (mT) near the substrate also varied within the range of values ​​shown in Figure 10.

[0086] For the coated tools of Samples No. 1 and No. 2, a plurality of Ta-containing laminate structures and a plurality of Mo-containing laminate structures were formed on the surface of a substrate. Here, the plurality of Ta-containing laminate structures and the plurality of Mo-containing laminate structures were alternately laminated. For the coated tool of Sample No. 3, only a plurality of Mo-containing laminate structures were formed on the surface of the substrate. For the coated tool of Sample No. 4, only a plurality of Ta-containing laminate structures were formed on the surface of the substrate.

[0087] Here, a set of a Ta-containing laminate structure and a Mo-containing laminate structure, only a Ta-containing laminate structure, and only a Mo-containing laminate structure were formed on the surface of the substrate for the number of laminations (times) shown in Fig. 10. That is, the number of Ta-containing laminate structures and the number of Mo-containing laminate structures were each the same as the number of laminations (times) shown in Fig. 10. Each of the Ta-containing laminate structures and the Mo-containing laminate structures was formed on the surface of the substrate for the lamination time (minutes) shown in Fig. 10.

[0088] As shown in Figure 11, for the coated tools of Samples 1 and 2, the Ta-containing layered structure was composed of a first compound layer and a second compound layer, and the Mo-containing layered structure was composed of a third compound layer and a fourth compound layer. For the coated tool of Sample 3, the Mo-containing layered structure was composed of a third compound layer and a fourth compound layer. For the coated tool of Sample 4, the Ta-containing layered structure was composed of a first compound layer and a second compound layer.

[0089] Each of the first compound layer and the second compound layer is made of (Al a Ti b Ta c)N, where a, b, and c were the values ​​shown in FIG. 11. The values ​​of a, b, and c shown in FIG. 11 were average values ​​for the Ta-containing compounds contained in the multiple first compound layers or multiple second compound layers included in the Ta-containing layered structure. The average composition of the Ta-containing layered structure composed of the first compound layer and the second compound layer matched the composition of the target for manufacturing the Ta-containing layered structure shown in FIG. 10.

[0090] As shown in Figure 11, for the coated tools of Samples No. 1 and No. 2, the relationships among a of the first compound layer, b of the first compound layer, c of the first compound layer, a of the second compound layer, b of the second compound layer, and c of the second compound layer were as follows: a of the first compound layer < a of the second compound layer, b of the first compound layer < b of the second compound layer, and c of the first compound layer > c of the second compound layer.

[0091] Each of the third compound layer and the fourth compound layer is made of (Al d Cr e Si f Mo g ) where d, e, f, and g were the values ​​shown in FIG. 11. The values ​​of d, e, f, and g shown in FIG. 11 were average values ​​for the Mo-containing compounds contained in the multiple third compound layers or multiple fourth compound layers included in the Mo-containing layered structure. The average composition of the Mo-containing layered structure composed of the third compound layers and the fourth compound matched the composition of the target for manufacturing the Mo-containing layered structure shown in FIG. 10.

[0092] As shown in Figure 11, the d of the third compound layer, the e of the third compound layer, the g of the third compound layer, the d of the fourth compound layer, the e of the fourth compound layer, and the g of the fourth compound layer had the following relationships: d of the third compound layer < d of the fourth compound layer, e of the third compound layer > e of the fourth compound layer, and g of the third compound layer > g of the fourth compound layer.

[0093] For the coating tools of Specimens No. 1 and No. 2, the thickness of each of the Ta-containing laminate and the Mo-containing laminate was 400 nm, which was the value of the thickness (nm) of each laminate as shown in Fig. 11. For the coating tool of Specimen No. 3, the thickness of the Mo-containing laminate was 4000 nm as shown in Fig. 11. For the coating tool of Specimen No. 4, the thickness of the Ta-containing laminate was 4000 nm as shown in Fig. 11.

[0094] For the coating tools of Specimens No. 1 and No. 2, the average thickness of the first compound layer, the second compound layer, the third compound layer, and the fourth compound layer was 8 nm, which was the value of the average thickness (nm) of the compound layers as shown in Fig. 11. For the coating tool of Specimen No. 3, the average thickness of the third compound layer and the fourth compound layer was 8 nm as shown in Fig. 11. For the coating tool of Specimen No. 4, the average thickness of the first compound layer and the second compound layer was 8 nm as shown in Fig. 11.

[0095] <X-ray diffraction spectrum> For the coating tools of Specimens No. 1 to No. 4, a heat treatment was carried out to hold the coating layer at 1200 °C for 0.5 hours in a nitrogen atmosphere. Then, an X-ray diffraction spectrum of the coating layer after the heat treatment was measured using an X-ray diffractometer "MiniFlex600" (manufactured by Rigaku Corporation). The optical system of the above X-ray diffractometer was a focusing method optical system. The X-ray tube of the above X-ray diffractometer was Cu, and its output was 40 kV / 15 mA.

[0096] The measurement conditions of the X-ray diffraction spectrum were as follows. Measurement method: 2θ scan Measurement range: 30 degrees to 46 degrees Step: 0.01 degree Scanning speed: 2 degrees / minute

[0097] Fig. 12A shows an X-ray diffraction spectrum measured for the coating layer of the coated tool of Sample No. 1 after heat treatment. Fig. 12B shows an X-ray diffraction spectrum measured for the coating layer of the coated tool of Sample No. 2 after heat treatment. Fig. 12C shows an X-ray diffraction spectrum measured for the coating layer of the coated tool of Sample No. 3 after heat treatment. Fig. 12D shows an X-ray diffraction spectrum measured for the coating layer of the coated tool of Sample No. 4 after heat treatment.

[0098] 12A, 12B, 12C, and 12D, the horizontal axis represents the diffraction angle 2θ (degrees) of the X-rays, and the vertical axis represents the intensity of the X-rays (arbitrary units), where θ is the Bragg angle (degrees) of the X-rays.

[0099] 12A, 12B, 12C, and 12D, the diffraction peak in the range of 33 to 34 degrees corresponds to the (100) plane of the hexagonal crystal of the metal nitride contained in the coating layer after heat treatment, and the diffraction peak in the range of 36.3 to 36.5 degrees corresponds to the (002) plane of the hexagonal crystal.

[0100] For each of the X-ray diffraction spectra shown in Figures 12A, 12B, 12C, and 12D, the intensity of the diffraction peak corresponding to the (100) plane of the hexagonal crystal, Ih(100), and the intensity of the diffraction peak corresponding to the (002) plane of the hexagonal crystal, Ih(002), were obtained. The ratio Ih(100) / Ih(002) was calculated from the obtained Ih(100) and Ih(002).

[0101] <Cutting test> Cutting tests were carried out on the coated tools of Samples No. 1 to No. 4. The test conditions for the cutting tests were as follows: A cemented carbide material for milling (model number: PNMU1205ANER-GM) was used as the substrate, and the cutting tests were carried out under the following conditions. (1) Cutting method: Milling using square lumber measuring 80mm x 125mm x 300mm (2) Workpiece material: FCD450 (3) Cutting speed Vc: 150 m / min and 200 m / min (4) Feed rate per tooth fz: 0.12 mm / t (5) Axial cutting depth ap: 2 mm (6) Processing method: dry and wet (7) Evaluation method: Milling was performed on the 80 mm × 300 mm surface of the workpiece under the above conditions, and the time when the Vb wear width on the tool flank reached 0.1 mm was determined to be the end of the coated tool's life.

[0102] FIG. 13 is a table showing the results of X-ray diffraction spectrum measurements and cutting tests for the coated tools of Samples No. 1 to No. 4.

[0103] As shown in Figure 13, for the coated tool of Sample No. 1, Ih(100) / Ih(002) was 0.29. For the coated tool of Sample No. 2, Ih(100) / Ih(002) was 0.9. For the coated tool of Sample No. 3, Ih(100) / Ih(002) was 1.57. For the coated tool of Sample No. 4, Ih(100) / Ih(002) was 1.75.

[0104] For the coated tools of Samples No. 1 and No. 2, the X-ray diffraction spectra measured on the coating layers after heat treatment satisfied the relationship Ih(100) / Ih(002)≦0.9. On the other hand, for the coated tools of Samples No. 3 and No. 4, the X-ray diffraction spectra measured on the coating layers after heat treatment did not satisfy the relationship Ih(100) / Ih(002)≦0.9. The coated tools of Samples No. 1 and No. 2 correspond to examples of the present disclosure. The coated tools of Samples No. 3 and No. 4 correspond to comparative examples of the present disclosure.

[0105] In this way, by forming the coating layer so that it includes a plurality of Ta-containing stacked structures and a plurality of Mo-containing stacked structures, each of the plurality of Ta-containing stacked structures includes a first compound layer containing Ta at a first composition ratio and a second compound layer containing Ta at a second composition ratio different from the first composition ratio, and each of the plurality of Mo-containing stacked structures includes a third compound layer containing Mo at a third composition ratio and a fourth compound layer containing Mo at a fourth composition ratio different from the third composition ratio, it was confirmed that it is possible to obtain a coating layer in which the X-ray diffraction spectrum measured for the coating layer after holding it at a temperature of 1200°C for 0.5 hours in a non-oxidizing atmosphere satisfies the relationship Ih(100) / Ih(002)≦0.9.

[0106] As shown in Figure 13, the lifespan of the coated tools of Samples No. 1 and No. 2 was equal to or longer than that of the coated tools of Samples No. 3 and No. 4 in both dry and wet cutting, and in both low-speed and high-speed cutting. Therefore, it was confirmed that the lifespan of the coated tools can be extended when the X-ray diffraction spectrum measured on the coating layer after holding at 1200°C for 0.5 hours in a non-oxidizing atmosphere satisfies the relationship Ih(100) / Ih(002)≦0.9.

[0107] Of the coated tools of Samples No. 1 and No. 2, the X-ray diffraction spectrum measured on the coating layer after heat treatment for Sample No. 1 satisfied the relationship Ih(100) / Ih(002)≦0.3. On the other hand, the X-ray diffraction spectrum measured on the coating layer after heat treatment for Sample No. 2 did not satisfy the relationship Ih(100) / Ih(002)≦0.3.

[0108] 13, the life of the coated tool of Sample No. 1 was longer than that of Sample No. 2 in both dry and wet cutting, and in both low-speed and high-speed cutting. Therefore, it was confirmed that the life of the coated tool can be further extended when the X-ray diffraction spectrum measured on the coating layer after holding at 1200°C for 0.5 hours in a non-oxidizing atmosphere satisfies the relationship Ih(100) / Ih(002)≦0.3.

[0109] As described above, a coated tool according to an embodiment (for example, the coated tool 1) includes a substrate (for example, the substrate 10) and a coating layer (for example, the coating layer 20) that is located on the substrate and is made of a cubic crystal. The X-ray diffraction spectrum measured for the coating layer after holding it at a temperature of 1200°C for 0.5 hours in a non-oxidizing atmosphere satisfies the relationship Ih(100) / Ih(002)≦0.9. Ih(100) is the intensity of the diffraction peak corresponding to the (100) plane of the hexagonal crystal formed in the coating layer. Ih(002) is the intensity of the diffraction peak corresponding to the (002) plane of the hexagonal crystal.

[0110] Therefore, the coated tool according to the embodiment can extend the life of the tool.

[0111] 1 is merely an example and does not limit the shape of the coated tool according to the present disclosure. A 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.

[0112] Supplementary note (1): A coated tool comprising a substrate and a coating layer located on the substrate and made of cubic crystals, wherein an X-ray diffraction spectrum measured on the coating layer after holding the coating layer at a temperature of 1200°C for 0.5 hours in a non-oxidizing atmosphere satisfies the relationship Ih(100) / Ih(002)≦0.9, where Ih(100) is the intensity of a diffraction peak corresponding to the (100) plane of a hexagonal crystal formed in the coating layer, and Ih(002) is the intensity of a diffraction peak corresponding to the (002) plane of the hexagonal crystal. Appendix (2): The coated tool according to Appendix (1), wherein the X-ray diffraction spectrum satisfies the relationship Ih(100) / Ih(002)≦0.3. Supplementary Note (3): A cutting tool comprising a rod-shaped holder having a pocket at an end thereof, and the coated tool according to Supplementary Note (1) or (2) positioned in the pocket.

[0113] 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. [Explanation of symbols]

[0114] 1 Coated tools 2 Chip body 3 Cutting edge 5 through holes 10 Base 20 Covering layer 21 Middle Class 22 Ta-containing laminated structure 22a First compound layer 22b Second compound layer 23 Mo-containing laminated structure 23a Third compound layer 23b Fourth compound layer 70 Holder 73 Pocket 75 screws 100 cutting tools 101 Vacuum Chamber 102 Gas inlet 103 Cathode electrode 104 Anode electrode 105 Target 106 Sample support table 107 Tower 108 Heater 109 Gas outlet 110 Bias power supply 1000 AIP devices

Claims

1. a substrate; a coating layer located on the substrate and made of cubic crystals; Equipped with an X-ray diffraction spectrum measured on the coating layer after holding it at a temperature of 1200°C for 0.5 hours in a non-oxidizing atmosphere satisfies the relationship Ih(100) / Ih(002)≦0.9; Ih(100) is the intensity of the diffraction peak corresponding to the (100) plane of the hexagonal crystal formed in the coating layer, Ih(002) is the intensity of the diffraction peak corresponding to the (002) plane of the hexagonal crystal; Coated tools.

2. The coated tool according to claim 1 , wherein the X-ray diffraction spectrum satisfies the relationship Ih(100) / Ih(002)≦0.

3.

3. The hexagonal crystals are formed by a phase transformation of the cubic crystals by holding the hexagonal crystals at a temperature of 1200°C for 0.5 hours in a non-oxidizing atmosphere. The coated tool according to claim 1 .

4. The coating layer after being held at a temperature of 1200°C for 0.5 hours in a non-oxidizing atmosphere contains the hexagonal crystals and the cubic crystals. The coated tool according to claim 1 .

5. a rod-shaped holder having a pocket at an end; The coated tool according to any one of claims 1 to 4, located in the pocket. A cutting tool comprising:

Images