Coated and cutting tools

Abstract

The coated tool according to the present invention has a substrate and a coating layer positioned on the substrate. The coated tool has a first face having a rake face, a second face having a flank, and a ridgeline section positioned between the first face and the second face. The first face has a plurality of corner sections in plan view. Cutting edges are positioned at ridgeline sections in the corner sections. The cutting edges have a third face in at least a portion thereof. The coating layer has a first coating layer positioned on the first face, a second coating layer positioned on the second face, and a third coating layer positioned on the third face. A recess having a bottom face and side walls is positioned in at least a portion of the third coating layer. When the distance between the bottom face and the substrate is a first distance, and the distance between the substrate and the surface of the coating layer in the side walls is a second distance, the first distance is 70% or less of the second distance.

Description

[Technical field]

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

[0002] As a tool used in cutting processes such as turning and milling, there are known coated tools in which the surface of a base material such as cemented carbide, cermet, ceramics, etc. is coated with a coating layer to improve wear resistance, etc. (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2002-3284 A Summary of the Invention

[0004] A coated tool according to one embodiment of the present disclosure includes a base and a coating layer located on the base. The coated tool includes a first surface having a rake face, a second surface having a flank face, and a ridge portion located between the first surface and the second surface. The first surface has a plurality of corners when viewed in a plan view. A cutting edge is located on the ridge portion at the corner. The cutting edge has a third surface at least in part. The coating layer includes a first coating layer located on the first surface, a second coating layer located on the second surface, and a third coating layer located on the third surface. A recess having a bottom surface and a side wall is located in at least a part of the third coating layer. When the distance between the bottom surface and the base is defined as a first distance and the distance between the surface of the coating layer at the side wall and the base is defined as a second distance, the first distance is 70% or less of the second distance.

[0005] A cutting tool according to one aspect of the present disclosure includes a rod-shaped holder having a pocket at an end thereof and the coated tool described above positioned within the pocket. [Brief description of the drawings]

[0006] [Figure 1]FIG. 1 is a perspective view showing an example of a coated tool according to an embodiment. [Diagram 2] FIG. 2 is a side cross-sectional view showing an example of a coated tool according to an embodiment. [Diagram 3] FIG. 3 is a schematic enlarged view of part III shown in FIG. [Figure 4] FIG. 4 is a schematic cross-sectional view showing an example of the configuration of the recess. [Diagram 5] FIG. 5 is a schematic cross-sectional view showing another example of the configuration of the recess. [Figure 6] FIG. 6 is a schematic plan view showing an example of the configuration of the recess. [Figure 7] FIG. 7 is a schematic plan view showing another example of the configuration of the recess. [Figure 8] FIG. 8 is a schematic plan view showing another example of the configuration of the recess. [Figure 9] FIG. 9 is a schematic plan view showing another example of the configuration of the recess. [Figure 10] FIG. 10 is a schematic plan view showing another example of the configuration of the recess. [Figure 11] FIG. 11 is a schematic cross-sectional view showing another example of the configuration of the coating layer. [Figure 12] FIG. 12 is a schematic enlarged view of part XII shown in FIG. [Figure 13] FIG. 13 is a schematic enlarged view of a portion XIII shown in FIG. [Figure 14] FIG. 14 is a front view showing an example of a cutting tool according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] Hereinafter, a detailed description will be given of a form for carrying out a coated tool and a cutting tool according to the present disclosure (hereinafter, referred to as an "embodiment") with reference to the drawings. Note that the coated tool and the cutting tool according to the present disclosure are not limited to the embodiment. Moreover, each embodiment can be appropriately combined as long as the processing contents are not contradictory. Moreover, the same parts in each of the following embodiments are given the same reference numerals, and duplicated explanations will be omitted.

[0008] In addition, in the embodiments described below, expressions such as "constant", "orthogonal", "vertical" and "parallel" may be used, but these expressions do not necessarily mean "constant", "orthogonal", "vertical" and "parallel" strictly. In other words, each of the above expressions allows for deviations due to, for example, manufacturing accuracy and installation accuracy.

[0009] There are known coated tools in which the surface of a substrate made of cemented carbide, cermet, ceramics, etc. is coated with a coating layer to improve wear resistance, etc. However, there is room for further improvement in this type of coated tool in terms of realizing a longer life.

[0010] <Coated tools> Fig. 1 is a perspective view showing an example of a coated tool according to an embodiment. As shown in Fig. 1, the coated tool 1 according to the embodiment may have a tip body 2 and a cutting edge portion 3. The coated tool 1 according to the embodiment 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 shapes.

[0011] The coated tool 1 has a first surface 6 (here, an upper surface), a second surface 7 (here, a side surface) connected to the first surface 6, and a ridge portion 8 located between the first surface 6 and the second surface 7. The first surface 6 has a scooping surface for scooping up chips generated by cutting. In addition, the second surface 7 has a flank surface.

[0012] The first surface 6 has a plurality of (four here) corners 61 in plan view. Here, the corners refer to areas including the corners of the first surface 6. A cutting edge 11 is located on a ridge line 8 of at least one of the plurality of corners 61. The coated tool 1 cuts a workpiece by bringing the cutting edge 11 into contact with the workpiece.

[0013] (Chip body 2) The tip body 2 is formed of, for example, a cemented carbide. The cemented carbide contains W (tungsten), specifically WC (tungsten carbide). The cemented carbide may also contain at least one of Ni (nickel) and Co (cobalt). The tip body 2 may also 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.

[0014] A seat 4 for attaching the cutting edge portion 3 may be located in one of the locations of the tip body 2 that corresponds to the corner 61 of the coated tool 1. A through hole 5 that passes through the tip body 2 from top to bottom may be located in the center of the tip body 2. A screw 75 for attaching the coated tool 1 to a holder 70 described later is inserted into the through hole 5 (see FIG. 14).

[0015] (Cutting edge 3) The cutting edge portion 3 is attached to the seat surface 4 of the tip body 2, and is thereby integrated with the tip body 2. The cutting edge portion 3 constitutes one of a plurality of corner portions 61 of the coated tool 1. The cutting edge portion 3 also constitutes the first surface 6, the second surface 7, and a part of the ridge portion 8 described above. The cutting edge 11 is located on at least a part of the ridge portion 8 of the cutting edge portion 3.

[0016] The configuration of the cutting edge portion 3 will be described with reference to Fig. 2. Fig. 2 is a side cross-sectional view showing an example of a coated tool 1 according to an embodiment. As shown in Fig. 2, the cutting edge portion 3 has a base body 10 and a coating layer 20.

[0017] (Base 10) The substrate 10 may be a cemented carbide, a cermet, or a ceramic. It may also contain a plurality of boron nitride particles. In the embodiment, the substrate 10 is a cubic boron nitride (cBN) sintered body and may contain a plurality of cubic boron nitride particles. The substrate 10 may have TiN, Al, Al between the plurality of boron nitride particles. 2 O 3 The substrate 10 may have a binder phase containing, for example, arsenic, niobium, arsenic, etc. The plurality of boron nitride particles are firmly bonded by the binder phase. The substrate 10 does not necessarily have to have a binder phase. Although the substrate 10 is located at the cutting edge portion 3 in Figs. 1 and 2, the substrate 10 may be the main body 2 and the cutting edge portion 3. In other words, for example, a rectangular substrate 10 may be used.

[0018] A third surface 9 continuous with the first surface 6 and the second surface 7 is located on at least a portion of the cutting edge 11. The third surface 9 is, for example, a C-surface (chamfered surface) obtained by cutting the corner between the first surface 6 and the second surface 7 obliquely and linearly. The third surface 9 may also be an R-surface (rounded surface) obtained by rounding the corner between the first surface 6 and the second surface 7.

[0019] A substrate 30 made of, for example, cemented carbide or cermet may be located on the lower surface of base 10. In this case, base 10 is joined to seating surface 4 of chip body 2 via substrate 30 and bonding material 40. Bonding material 40 is, for example, brazing material. In the portion of chip body 2 other than seating surface 4, base 10 may be joined to chip body 2 via bonding material 40.

[0020] (Coating layer 20) The coating layer 20 is applied to the base 10 for the purpose of improving the wear resistance, heat resistance, etc. of the cutting edge portion 3. In the example of Fig. 2, the coating layer 20 is located on both the tip body 2 and the base 10, but it is sufficient that the coating layer 20 is located at least on the base 10. When the coating layer 20 is located on the side surface of the base 10 corresponding to the second surface 7 of the cutting edge portion 3, the second surface 7 has high wear resistance and heat resistance.

[0021] Fig. 3 is a schematic enlarged view of part III shown in Fig. 2. As shown in Fig. 3, the coating layer 20 has a first coating layer 201 located on the first surface 6, a second coating layer 202 located on the second surface 7, and a third coating layer 203 located on the third surface 9.

[0022] Of the first coating layer 201, the second coating layer 202, and the third coating layer 203, recesses 50 are located in at least a portion of the third coating layer 203. In the embodiment, the third coating layer 203 has a plurality of recesses 50. The configuration of the recesses 50 will be described with reference to Fig. 4. Fig. 4 is a schematic cross-sectional view showing an example of the configuration of the recesses 50.

[0023] 4, the recess 50 is recessed along the thickness direction of the third coating layer 203, that is, from the surface of the third coating layer 203 toward the third face 9 of the base 10. The recess 50 has a bottom surface 51 and a side wall 52.

[0024] Here, the distance between the bottom surface 51 and the base 10 is defined as a first distance D1, and the distance between the surface of the coating layer 20 at the side wall 52 and the base 10 is defined as a second distance D2. Note that "the second distance D2 at the side wall 52" specifically means that the shortest distance from the edge between the surface of the third coating layer 203 and the side wall 52 of the recess 50 (i.e., the opening edge of the recess 50) to the base 10 is the second distance D2.

[0025] The first distance D1 is 70% or less of the second distance D2. In this way, the recess 50 is not a depression caused by, for example, the surface roughness of the third coating layer 203, but is formed intentionally (specifically, by laser processing as described below). Preferably, the first distance D1 is 50% or less of the second distance D2. More preferably, the first distance D1 is 30% or less of the second distance D2.

[0026] In this manner, a plurality of recesses 50 are located in the third coating layer 203 according to the embodiment. On the other hand, the above-mentioned recesses 50 are not located in the first coating layer 201 and the second coating layer 202. The third coating layer 203 has a smaller adhesion to the substrate 10 than the first coating layer 201 and the second coating layer 202.

[0027] The inventors of the present application have found that the life of the coated tool 1 can be extended by relatively reducing the adhesion of the third coating layer 203 located on the third surface 9. One of the reasons for this is that in the case of processing in which a thermal shock is applied to the coated tool 1, such as when the coated tool 1 performs intermittent cutting while in contact with a coolant, if the adhesion of the third coating layer 203 is strong, the third coating layer 203 is damaged together with the base material, that is, the substrate 10, when it is destroyed.

[0028] Therefore, in the coated tool 1 according to the embodiment, a plurality of recesses 50 are provided in the third coating layer 203, so that the adhesion between the third coating layer 203 and the substrate 10 is made smaller than the adhesion between the first coating layer 201 and the second coating layer 202 and the substrate 10. The coated tool 1 having such a configuration can suppress damage to the substrate 10 at the third surface 9. Therefore, the coated tool 1 according to the embodiment can achieve a longer life.

[0029] Furthermore, since the third coating layer 203 has a relatively small adhesive strength, it is removed from the third surface 9 as the workpiece is cut, for example, at the beginning of use of the coated tool 1 (for example, at the first use). Therefore, according to the coated tool 1, it is easy to determine whether the tool is unused or used by checking the presence or absence of the third coating layer 203. Note that it is preferable that the coating layer 20 has a color different from that of the base body 10. In this case, it is easy to visually determine whether the tool is unused or used.

[0030] 5 is a schematic cross-sectional view showing another example of the configuration of the recess 50. As shown in FIG. 5, the recess 50 may penetrate the third coating layer 203. That is, the bottom surface 51 of the recess 50 may be the third surface 9 of the base body 10. With this configuration, the adhesion of the third coating layer 203 to the base body 10 can be further reduced compared to the first coating layer 201 and the second coating layer 202. Therefore, the life of the coated tool 1 can be further extended.

[0031] The recesses 50 may occupy 10% or more of the area of ​​the surface of the third coating layer 203. With this configuration, the adhesive force between the third coating layer 203 and the substrate 10 can be appropriately reduced, and the life of the coated tool 1 can be extended.

[0032] Fig. 6 is a schematic plan view showing an example of the configuration of the recess 50. Fig. 6 shows a plan view of the third coating layer 203 viewed from a direction perpendicular to the third surface 9. As shown in Fig. 6, the recess 50 may extend linearly along the ridge line 8 when viewed from above. With this configuration, the frictional force between the workpiece and the third coating layer 203 during machining is large, so that the third coating layer 203 is easily removed.

[0033] 7 to 10 are schematic plan views showing other examples of the configuration of the recess 50. For example, as shown in Fig. 7, the recess 50 may extend linearly in a direction intersecting with the direction along the ridge line 8 on the third surface 9 in a plan view. With such a configuration, cooling water is easily supplied to the recess 50, and the coated tool 1 is easily cooled.

[0034] 8, the recess 50 may have a portion 55 extending linearly along the ridge 8 and a portion 56 extending linearly in a direction intersecting the direction along the ridge 8 on the third surface 9 in a plan view. In this case, the recess 50 may extend in a lattice shape as a whole. With this configuration, the third coating layer 203 is removed more uniformly when the coated tool 1 is used. In other words, it is possible to prevent the third coating layer 203 from remaining on the third surface 9.

[0035] 9, recess 50 may have a portion 55 extending linearly along ridgeline 8, and a portion 56 extending linearly in a direction intersecting with the direction along ridgeline 8 on third surface 9. In this case, these portions 55, 56 may be alternately connected to form a single recess 50 that extends in a unicursal, meandering manner.

[0036] 10, the recess 50 may be a hole extending only in the thickness direction of the third coating layer 203. Although a round hole is shown here as an example, the recess 50 may be a square hole. In this way, the recess 50 does not necessarily need to extend along the third surface 9.

[0037] Fig. 11 is a schematic cross-sectional view showing another example of the configuration of the coating layer 20. As shown in Fig. 11, the thickness of the third coating layer 203 may be thinner in a region close to the first surface 6 than in a region close to the second surface 7. In other words, the thickness of the third coating layer 203 may gradually increase from the first surface 6 toward the second surface 7. The coated tool 1 having such a configuration has a good balance of fracture resistance, wear resistance, and heat resistance.

[0038] In this case, the depth of the recesses 50 located in the region closer to the second surface 7 may be deeper than the recesses 50 located in the region closer to the first surface 6. Note that, although an example in which the recesses 50 extend in a direction perpendicular to the third surface 9 is shown here, the recesses 50 may extend in a direction perpendicular to the surface of the third coating layer 203.

[0039] In this case, third coating layer 203 may be formed, for example, by forming a coating layer of uniform thickness on third surface 9 and then removing a portion of the coating layer.

[0040] (Specific configuration of covering layer 20) Next, a specific configuration of the coating layer 20 will be described with reference to Fig. 12. Fig. 12 is a schematic enlarged view of a portion XII shown in Fig. 3.

[0041] As shown in FIG. 12, the coating layer 20 has at least a hard layer 21. The hard layer 21 may have one or more metal nitride layers. The hard layer 21 is a layer having superior wear resistance compared to the metal layer 22. The hard layer 21 may be a single layer. Alternatively, a plurality of metal nitride layers may be overlapped. Alternatively, the hard layer 21 may have a laminated portion 23 in which a plurality of metal nitride layers are laminated, and a third metal nitride layer 24 located on the laminated portion 23. The configuration of the hard layer 21 will be described later.

[0042] (metal layer 22) The coating layer 20 may also have a metal layer 22. The metal layer 22 may be located between the substrate 10 and the hard layer 21. Specifically, the metal layer 22 may be in contact with the substrate 10 on one surface and in contact with the hard layer 21 on the other surface.

[0043] The metal layer 22 has higher adhesion to the substrate 10 than the hard layer 21. Examples of metal elements having such properties include Zr, V, Cr, W, Al, Si, and Y. The metal layer 22 contains at least one of the above metal elements.

[0044] Note that simple elements of Ti, Zr, V, Cr, and Al are not used as the metal layer 22. These elements all have low melting points and low oxidation resistance, making them unsuitable for use in cutting tools. Also, simple elements of Hf, Nb, Ta, and Mo have low adhesion to the substrate 10. However, this does not apply to alloys containing Ti, Zr, V, Cr, Ta, Nb, Hf, and Al.

[0045] The metal layer 22 may be an Al-Cr alloy layer containing an Al-Cr alloy. Such a metal layer 22 has a particularly high adhesion to the substrate 10, and is therefore highly effective in improving the adhesion between the substrate 10 and the coating layer 20.

[0046] When the metal layer 22 is an Al-Cr alloy layer, the Al content in the metal layer 22 may be greater than the Cr content in the metal layer 22. For example, the composition ratio (atomic %) of Al to Cr in the metal layer 22 may be 70:30. With such a composition ratio, the adhesion between the substrate 10 and the metal layer 22 is higher.

[0047] The metal layer 22 may contain components other than the above metal elements (Zr, V, Cr, W, Al, Si, Y). However, from the viewpoint of adhesion to the substrate 10, the metal layer 22 may contain at least 95 atomic % or more of the above metal elements in total. More preferably, the metal layer 22 may contain at least 98 atomic % or more of the above metal elements in total. For example, when the metal layer 22 is an Al-Cr alloy layer, the metal layer 22 may contain at least Al and Cr in total of 95 atomic % or more. Furthermore, the metal layer 22 may contain at least Al and Cr in total of 98 atomic % or more. The ratio of the metal components in the metal layer 22 can be identified by, for example, analysis using EDS (energy dispersive X-ray spectrometry).

[0048] Moreover, since Ti has poor wettability with the base 10 according to the embodiment, it is preferable that the metal layer 22 contains as little Ti as possible from the viewpoint of improving adhesion with the base 10. Specifically, the Ti content in the metal layer 22 may be 15 atomic % or less.

[0049] In this manner, in the coated tool 1 according to the embodiment, the metal layer 22, which has higher wettability with the substrate 10 than the hard layer 21, is provided between the substrate 10 and the hard layer 21, thereby improving the adhesion between the substrate 10 and the coating layer 20. Since the metal layer 22 also has high adhesion with the hard layer 21, the hard layer 21 is unlikely to peel off from the metal layer 22.

[0050] Moreover, cBN used as the substrate 10 is an insulator. As an insulator, cBN has room for improvement in adhesion with a film formed by a PVD (physical vapor deposition) method. In contrast, in the coated tool 1 according to the embodiment, by providing a conductive metal layer 22 on the surface of the substrate 10, adhesion between the hard layer 21 formed by PVD and the metal layer 22 is high.

[0051] (hard layer 21) Next, the configuration of the hard layer 21 will be described with reference to Fig. 13. Fig. 13 is a schematic enlarged view of part XIII shown in Fig. 12.

[0052] As shown in FIG. 13, the hard layer 21 has a laminated portion 23 located on the metal layer 22, and a third metal nitride layer 24 located on the laminated portion 23.

[0053] The laminated portion 23 has a plurality of first metal nitride layers 23a and a plurality of second metal nitride layers 23b. The laminated portion 23 has a configuration in which the first metal nitride layers 23a and the second metal nitride layers 23b are alternately laminated.

[0054] The thickness of each of the first metal nitride layer 23a and the second metal nitride layer 23b may be 50 nm or less. By forming the first metal nitride layer 23a and the second metal nitride layer 23b thin in this manner, the residual stress of the first metal nitride layer 23a and the second metal nitride layer 23b is small. As a result, for example, peeling or cracking of the first metal nitride layer 23a and the second metal nitride layer 23b is less likely to occur, and the durability of the coating layer 20 is high.

[0055] The first metal nitride layer 23a is a layer in contact with the metal layer 22, and the second metal nitride layer 23b is formed on the first metal nitride layer 23a.

[0056] The first metal nitride layer 23a and the second metal nitride layer 23b may contain the metal contained in the metal layer 22.

[0057] For example, suppose that metal layer 22 contains two types of metals (herein referred to as a "first metal" and a "second metal"). In this case, first metal nitride layer 23a contains nitrides of the first metal and a third metal. The third metal is a metal not contained in metal layer 22. In addition, second metal nitride layer 23b contains nitrides of the first metal and the second metal.

[0058] For example, in the embodiment, the metal layer 22 may contain Al and Cr. In this case, the first metal nitride layer 23a may contain Al. Specifically, the first metal nitride layer 23a may be an AlTiN layer containing AlTiN, which is a nitride of Al and Ti. Also, the second metal nitride layer 23b may be an AlCrN layer containing AlCrN, which is a nitride of Al and Cr.

[0059] In this manner, by positioning the first metal nitride layer 23a containing the metal contained in the metal layer 22 on the metal layer 22, the adhesion between the metal layer 22 and the hard layer 21 is high. This makes it difficult for the hard layer 21 to peel off from the metal layer 22, and therefore the durability of the coating layer 20 is high.

[0060] The first metal nitride layer 23a, i.e., the AlTiN layer, has excellent adhesion to the metal layer 22, for example, in wear resistance. The second metal nitride layer 23b, i.e., the AlCrN layer, has excellent heat resistance and oxidation resistance, for example. In this way, the coating layer 20 includes the first metal nitride layer 23a and the second metal nitride layer 23b, which have different compositions, and thus the characteristics of the hard layer 21, such as wear resistance and heat resistance, can be controlled. This can extend the tool life of the coated tool 1. For example, in the hard layer 21 according to the embodiment, mechanical properties such as adhesion to the metal layer 22 and wear resistance can be improved while maintaining the excellent heat resistance of AlCrN.

[0061] The laminated portion 23 may be formed by, for example, an arc ion plating method (AIP method). The AIP method uses arc discharge in a vacuum atmosphere to evaporate target metals (here, an AlTi target and an AlCr target), and then deposits N2 This is a method for forming a film of metal nitride (here, AlTiN and AlCrN) by combining with a gas. The metal layer 22 may also be formed by the AIP method.

[0062] The third metal nitride layer 24 may be located on the laminated portion 23. Specifically, the third metal nitride layer 24 contacts the second metal nitride layer 23b of the laminated portion 23. The third metal nitride layer 24 is, for example, a metal nitride layer containing Ti and Al (AlTiN layer) like the first metal nitride layer 23a.

[0063] The thickness of the third metal nitride layer 24 may be thicker than the thicknesses of the first metal nitride layer 23a and the second metal nitride layer 23b. Specifically, when the thicknesses of the first metal nitride layer 23a and the second metal nitride layer 23b are 50 nm or less as described above, the thickness of the third metal nitride layer 24 may be 1 μm or more. For example, the thickness of the third metal nitride layer 24 may be 1.2 μm.

[0064] As a result, for example, when the friction coefficient of the third metal nitride layer 24 is low, the adhesion resistance of the coated tool 1 can be improved. Also, for example, when the hardness of the third metal nitride layer 24 is high, the wear resistance of the coated tool 1 can be improved. Also, for example, when the oxidation onset temperature of the third metal nitride layer 24 is high, the oxidation resistance of the coated tool 1 can be improved.

[0065] Furthermore, the thickness of third metal nitride layer 24 may be thicker than the thickness of laminated portion 23. Specifically, in the embodiment, when the thickness of laminated portion 23 is 0.5 μm or less, the thickness of third metal nitride layer 24 may be 1 μm or more. For example, when the thickness of laminated portion 23 is 0.3 μm, the thickness of third metal nitride layer 24 may be 1.2 μm. In this way, by making third metal nitride layer 24 thicker than laminated portion 23, the effect of improving the above-mentioned adhesion resistance, wear resistance, etc. is further enhanced.

[0066] The thickness of metal layer 22 may be, for example, not less than 0.1 μm and less than 0.6 μm. That is, metal layer 22 may be thicker than each of first metal nitride layer 23a and second metal nitride layer 23b, and thinner than stacked portion 23.

[0067] (Method of manufacturing coated tool 1) Next, an example of a manufacturing method of the coated tool 1 will be described. Here, an example of a manufacturing method will be described when the substrate 10 is made of cBN. First, a method of manufacturing the coated tool 1 will be described. 2 O 3 Raw material powders having a concentration of 1% by volume or more and 11% by volume or less are prepared. An organic solvent is then added to each of the prepared raw material powders. As the organic solvent, alcohols such as acetone and isopropyl alcohol (IPA) can be used. Then, the raw material powders are pulverized and mixed in a ball mill for 20 hours to 24 hours. After pulverization and mixing, the solvent is evaporated to obtain a first mixed powder.

[0068] Next, cBN powder having an average particle size of 2.5 μm to 4.5 μm and cBN powder having an average particle size of 0.5 μm to 1.5 μm are mixed in a volume ratio of 8 to 9:1 to 2.0. An organic solvent is then added. As the organic solvent, alcohols such as acetone and IPA can be used. The mixture is then pulverized and mixed in a ball mill for 20 to 24 hours. After pulverization and mixing, the solvent is evaporated to obtain a second mixed powder.

[0069] Next, the obtained first mixed powder and second mixed powder are mixed in a volume ratio of 68 to 78:22 to 32. An organic solvent and an organic binder are added to the mixed powder. As the organic solvent, alcohols such as acetone and IPA can be used. As the organic binder, paraffin, acrylic resin, etc. can be used. Then, the mixture is pulverized and mixed in a ball mill for 20 to 24 hours, and the organic solvent is evaporated to obtain a third mixed powder. In addition, a dispersant may be added in the process using the ball mill as necessary.

[0070] The third mixed powder is then molded into a desired shape to obtain a molded body. For molding, known methods such as uniaxial pressing and cold isostatic pressing (CIP) can be used. The molded body is heated to a desired temperature within a range of 300°C to 600°C to evaporate and remove the organic binder.

[0071] Next, the compact is placed in an ultra-high pressure heating device and heated at 1200°C to 1500°C for 15 minutes to 30 minutes under a pressure of 4 GPa to 6 GPa. This produces a cubic boron nitride sintered body according to the embodiment. The cubic boron nitride sintered body is then attached to the seat of a tip body made of cemented carbide via a bonding material. This produces a tip according to the embodiment.

[0072] Next, the coating layer 20 is formed on the surface of the chip by physical vapor deposition (PVD). After that, the recesses 50 are formed in the third coating layer 203 by laser processing. In this way, the coated tool 1 is obtained.

[0073] <Cutting tools> Next, the configuration of a cutting tool including the above-mentioned coated tool 1 will be described with reference to Fig. 14. Fig. 14 is a front view showing an example of a cutting tool according to an embodiment.

[0074] As shown in FIG. 14, a cutting tool 100 according to the embodiment includes a coated tool 1 and a holder 70 for fixing the coated tool 1.

[0075] The holder 70 is a rod-shaped member extending from a first end (the upper end in FIG. 14) to a second end (the lower end in FIG. 14). The holder 70 is made of, for example, steel or cast iron. Of these materials, it is particularly preferable to use steel, which has high toughness.

[0076] 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 screwed.

[0077] The coated tool 1 is positioned in a pocket 73 of the holder 70, and is 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 screw 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 such that the cutting edge portion 3 protrudes outward from the holder 70.

[0078] In the embodiment, a cutting tool used for so-called turning is exemplified. Examples of turning include inner diameter machining, outer diameter machining, and grooving. The cutting tool is not limited to the one used for turning. For example, the coated tool 1 may be used as a cutting tool used for turning.

[0079] For example, cutting of a workpiece includes (1) a step of rotating the workpiece, (2) a step of bringing the cutting edge 11 of the coated tool 1 into contact with the rotating workpiece to cut the workpiece, and (3) a step of removing the coated tool 1 from the workpiece. Representative examples of the material of the workpiece include carbon steel, alloy steel, stainless steel, cast iron, and non-ferrous metals.

[0080] <Other embodiments> In the above-described embodiment, a coated tool 1 has been described in which a substrate 10 made of boron nitride particles or the like is attached to a tip body 2 made of cemented carbide or the like, and these are coated with a coating layer 20. However, the coated tool according to the present disclosure may be, for example, a hexahedral substrate whose upper and lower surfaces are parallelogram-shaped, and the entire substrate is made of a cubic boron nitride sintered body, with a coating layer formed on such a substrate.

[0081] In the above embodiment, an example was shown in which the shapes of the upper and lower surfaces of the coated tool 1 are parallelograms, but the shapes of the upper and lower surfaces of the coated tool 1 may be rhombus, square, etc. Also, the shapes of the upper and lower surfaces of the coated tool 1 may be triangle, pentagon, hexagon, etc.

[0082] The shape of the coated tool 1 may be a positive type or a negative type. The positive type is a type in which the side surface is inclined with respect to a central axis passing through the center of the upper surface and the center of the lower surface of the coated tool 1, and the negative type is a type in which the side surface is parallel to the central axis.

[0083] In the above-described embodiment, an example in which the substrate 10 contains particles of cubic boron nitride (cBN) has been described. The substrate disclosed in the present application may contain particles of hexagonal boron nitride (hBN), rhombohedral boron nitride (rBN), wurtzite boron nitride (wBN), or the like. The substrate 10 is not limited to boron nitride, and may be, for example, a cemented carbide or a cermet. The cemented carbide contains W (tungsten), specifically WC (tungsten carbide). The cemented carbide may contain Ni (nickel) or Co (cobalt). The cermet contains, for example, Ti (titanium), specifically TiC (titanium carbide) or TiN (titanium nitride). The cermet may contain Ni or Co.

[0084] In the above embodiment, the coated tool 1 has been described as being used for cutting processing, but the coated tool according to the present application can also be applied to tools other than cutting tools, such as excavation tools and blades.

[0085] Further advantages and modifications may readily occur to those skilled in the art. Thus, 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 equivalents thereof. [Explanation of symbols]

[0086] 1: Coated tools 2: Chip body 3: Cutting edge 6: 1st page 7:Second side 8: Ridge 9:Third side 10: Base 11: Cutting edge 20: Covering layer 21:Hard layer 22: Metal layer 23: Laminated section 30: Substrate 50: Recess 51: Bottom 52: Side wall 61: Corner 100:Cutting tools 201: 1st coating layer 202:Second coating layer 203:Third coating layer D1: First distance D2: 2nd distance

Claims

1. A substrate; a coating layer overlying the substrate, The coated tool comprises: a first surface having a rake surface; a second surface having a flank surface; a ridge portion located between the first surface and the second surface; having The first surface has a plurality of corners when viewed in a plan view, A cutting edge is located on the ridge portion at the corner portion, The cutting edge has at least a portion having a third surface, The coating layer is a first coating layer located on the first surface; a second coating layer located on the second surface; a third coating layer located on the third surface; and having A recess having a bottom surface and a side wall is located in at least a portion of the third coating layer, When the distance between the bottom surface and the base is a first distance, and the distance between the surface of the coating layer on the side wall and the base is a second distance, The first distance is equal to or less than 70% of the second distance, The recess extends linearly in a direction intersecting with a direction along the ridge line.

2. A substrate; a coating layer overlying the substrate, The coated tool comprises: a first surface having a rake surface; a second surface having a flank surface; a ridge portion located between the first surface and the second surface; having The first surface has a plurality of corners when viewed in a plan view, A cutting edge is located on the ridge portion at the corner portion, The cutting edge has at least a portion having a third surface, The coating layer is a first coating layer located on the first surface; a second coating layer located on the second surface; a third coating layer located on the third surface; and having A recess having a bottom surface and a side wall is located in at least a portion of the third coating layer, When the distance between the bottom surface and the base is a first distance, and the distance between the surface of the coating layer on the side wall and the base is a second distance, The first distance is equal to or less than 70% of the second distance, The recess has a portion extending linearly in a direction along the ridge line and a portion extending linearly in a direction intersecting the direction along the ridge line.

3. The coated tool according to claim 1 or 2, wherein the recess penetrates the third coating layer, and a bottom surface of the recess is the base body.

4. 4. The coated tool according to claim 1, wherein the recesses occupy 10% or more by area of ​​the surface of the third coating layer.

5. The coated tool according to any one of claims 1 to 4, wherein the substrate contains cubic boron nitride particles.

6. The coating layer is A hard layer; a metal layer that is an alloy containing at least one element selected from the group consisting of Ti, Zr, V, Cr, Ta, Nb, Hf, and Al, and is located between the substrate and the hard layer; The coated tool according to any one of claims 1 to 5, comprising:

7. The coated tool according to claim 6 , wherein the metal layer further contains at least one element selected from the group consisting of W, Si and Y.

8. a rod-shaped holder having a pocket at one end; The coated tool according to any one of claims 1 to 7, which is located in the pocket. A cutting tool having

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