cutting tools

Abstract

To provide a cutting tool having a long tool life.SOLUTION: A cutting tool includes a base material, and a film arranged on the base material, wherein the cutting tool includes a rake face, a flank face continuing to the rake face, and a cutting edge composed of a boundary part between the rake face and the flank face, the film includes a TiAlCeN layer, the TiAlCeN layer has a first TiAlCeN layer positioned on the rake face or the flank face, and a second TiAlCeN layer positioned on the cutting edge, the composition of the first TiAlCeN layer is Tix1Aly1Cez1 N, the composition of the second TiAlCeN layer is Tix2Aly2Cez2 N, wherein, x1+y1+z1=1, x2+y2+z2=1, 0.300<y1≤0.700, 0.300<y2≤0.700, 0.010<z1≤0.100, 0<z2≤0.090 and z1-z2≥0.010.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] Conventionally, in order to improve the performance of cutting tools, development of coatings that coat the surface of a substrate made of cemented carbide, cubic boron nitride sintered body, etc. has been underway. For example, Patent Document 1 discloses a coating film that coats the surface of a tool substrate with the composition formula: (Ti 1-x-y Al x M y )N z A cutting tool is disclosed that includes a composite nitride coating represented by the composition formula (wherein M is at least one of the group 6 elements of the periodic table, Y, Si, La, and Ce). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2020 / 166466 Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, for example, a TiAlCeN film using cerium (Ce) as M has high hardness but tends to have low toughness. When the TiAlCeN film is used under machining conditions that place a large load on the cutting edge (for example, intermittent machining of steel), the cutting edge is prone to fracture, and the tool life tends to be shortened.

[0005] Therefore, an object of the present disclosure is to provide a cutting tool having a long tool life. [Means for solving the problem]

[0006] The cutting tool of the present disclosure comprises: 1. A cutting tool comprising a substrate and a coating disposed on the substrate, The cutting tool comprises: Rake face, a flank surface connected to the rake surface; and a cutting edge formed by a boundary portion between the rake face and the flank face, the coating includes a TiAlCeN layer; The TiAlCeN layer is a first TiAlCeN layer located on the rake face or the flank face; a second TiAlCeN layer located on the cutting edge; The composition of the first TiAlCeN layer is Ti x1 Al y1 Ce z1 N, The composition of the second TiAlCeN layer is Ti x2 Al y2 Ce z2 N, where: x1+y1+z1=1, x2+y2+z2=1, 0.300 <y1≦0.700、 0.300 <y2≦0.700、 0.010 <z1≦0.100、 0 <z2≦0.090、および、 A cutting tool, wherein z1-z2≧0.010. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to provide a cutting tool having a long tool life. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view illustrating an example of a cutting tool according to an embodiment of the present disclosure. [Figure 2] 2 is a cross-sectional view of the cutting tool of FIG. 1, taken along the line II-II in FIG. [Figure 3] FIG. 3 is a cross-sectional perspective view showing the shaded portion of FIG. 1, and shows the area III. [Figure 4]FIG. 4 is a partial view of the cross section shown in FIG. 2 in which the cutting edge has been honed. [Figure 5] FIG. 5 is a cross-sectional perspective view showing the cutting edge of the cutting tool shown in FIG. 3 after honing. [Figure 6] FIG. 6 is a partial view of the cross-sectional view shown in FIG. 2 in which a negative land is machined on the cutting edge. [Figure 7] FIG. 7 is a cross-sectional perspective view of the cutting edge shown in FIG. 3, in which a negative land is formed on the cutting edge. [Figure 8] FIG. 8 is a partial view of the cross section shown in FIG. 2 in which the cutting edge has been subjected to honing and negative land machining. [Figure 9] FIG. 9 is a cross-sectional perspective view of the cutting edge shown in FIG. 3, in which honing and negative land processing are performed on the cutting edge. [Figure 10] FIG. 10 is a schematic cross-sectional view illustrating an example of a coating of a cutting tool according to an embodiment of the present disclosure. [Figure 11] FIG. 11 is a diagram for explaining the cutting position of the cutting tool. [Figure 12] FIG. 12 is a diagram for explaining the cutting position of the cutting tool. [Figure 13] FIG. 13 is a diagram for explaining a method for setting the measurement field of view in measuring the composition of a TiAlCeN layer. [Figure 14] FIG. 14 is a schematic cross-sectional view illustrating an example of a coating of a cutting tool according to an embodiment of the present disclosure. [Figure 15] FIG. 15 is a diagram showing an example of the positional relationship between a target material, a substrate, and a shielding material in a chamber of a film forming apparatus. [Figure 16] FIG. 16 is a diagram showing an example of the positional relationship between a target material, a substrate, and a shielding material in a chamber of a film forming apparatus. DETAILED DESCRIPTION OF THE INVENTION

[0009] [Description of the embodiments of the present disclosure] First, embodiments of the present disclosure will be listed and described. (1) The cutting tool of the present disclosure is 1. A cutting tool comprising a substrate and a coating disposed on the substrate, The cutting tool comprises: Rake face, a flank surface connected to the rake surface; and a cutting edge formed by a boundary portion between the rake face and the flank face, the coating includes a TiAlCeN layer; The TiAlCeN layer is a first TiAlCeN layer located on the rake face or the flank face; a second TiAlCeN layer located on the cutting edge; The composition of the first TiAlCeN layer is Ti x1 Al y1 Ce z1 N, The composition of the second TiAlCeN layer is Ti x2 Al y2 Ce z2 N, where: x1+y1+z1=1, x2+y2+z2=1, 0.300 <y1≦0.700、 0.300 <y2≦0.700、 0.010 <z1≦0.100、 0 <z2≦0.090、および、 A cutting tool, wherein z1-z2≧0.010.

[0010] According to the present disclosure, it is possible to provide a cutting tool having a long tool life.

[0011] (2) In the above (1), the thickness of the TiAlCeN layer is preferably 0.5 μm or more and 15 μm or less, which further improves the tool life.

[0012] (3) In the above (1) or (2), the coating further includes a first layer, The first layer is at least one element selected from Group 1 consisting of Group 4 elements, Group 5 elements, Group 6 elements, aluminum, and silicon of the periodic table; or It is preferable that the first compound comprises at least one element selected from the first group and at least one element selected from the second group consisting of carbon, nitrogen, oxygen, and boron.

[0013] This further improves the tool life.

[0014] (4) In the above (3), the first group preferably consists of titanium, chromium, aluminum, and silicon, which further improves the tool life.

[0015] (5) In any of the above (1) to (4), the thickness of the coating is preferably 0.5 μm or more and 15 μm or less, which further improves the tool life.

[0016] (6) In the above (3) or (4), the coating preferably has a multilayer structure in which the TiAlCeN layers and the first layers are alternately stacked, thereby further improving tool life.

[0017] [Details of the embodiments of the present disclosure] Specific examples of cutting tools according to the present disclosure will be described below with reference to the drawings. In the drawings, the same reference numerals represent the same or corresponding parts. Furthermore, dimensional relationships such as length, width, thickness, and depth have been appropriately changed for clarity and simplification of the drawings, and do not necessarily represent actual dimensional relationships.

[0018] In this specification, the expression "A to B" means the upper and lower limits of a range (i.e., A or more and B or less), and when no unit is specified for A and a unit is specified only for B, the unit of A and the unit of B are the same.

[0019] In this specification, when a compound is expressed by a chemical formula, unless the atomic ratio is particularly limited, it is understood to include any conventionally known atomic ratio and is not necessarily limited to only the stoichiometric range. For example, when "TiCN" is written, the ratio of the numbers of atoms constituting TiCN includes any conventionally known atomic ratio.

[0020] In the present disclosure, when one or more numerical values ​​are listed as the lower limit and the upper limit of a numerical range, a combination of any one numerical value listed as the lower limit and any one numerical value listed as the upper limit is also disclosed. For example, when a1 or more, b1 or more, and c1 or more are listed as the lower limit and a2 or less, b2 or less, and c2 or less are listed as the upper limit, a1 or more and a2 or less, a1 or more and b2 or less, a1 or more and c2 or less, b1 or more and a2 or less, b1 or more and b2 or less, b1 or more and c2 or less, c1 or more and a2 or less, c1 or more and b2 or less, and c1 or more and c2 or less are also disclosed.

[0021] First, in order to obtain a cutting tool with a long tool life, the inventors investigated the damage patterns of conventional tools under machining conditions that place a heavy load on the cutting edge. Under such machining conditions, the cutting edge is subjected to impacts, which tend to cause microchipping of the cutting edge. Furthermore, thermal wear is likely to occur on the rake face, and mechanical wear is likely to occur on the flank face due to contact with chips.

[0022] From the above investigations, it is inferred that for a cutting tool to have a long tool life, it is important to have excellent fracture resistance on the cutting edge and excellent wear resistance on the rake face or flank face. However, because fracture resistance and wear resistance are contradictory properties, it has been difficult to improve both fracture resistance and wear resistance in the same coating.

[0023] As a result of extensive research, the inventors have obtained a cutting tool that has a long tool life even under machining conditions that place a heavy load on the cutting edge by changing the composition of the coating on the cutting edge and the rake face or flank, thereby improving the fracture resistance of the cutting edge and the wear resistance of the rake face or flank in a well-balanced manner. One embodiment of the present invention (hereinafter also referred to as "this embodiment") will be described below, but the present embodiment is not limited thereto.

[0024] [Embodiment 1: Cutting tool (1)] According to one embodiment of the present disclosure, there is provided a cutting tool comprising: 1. A cutting tool comprising a substrate and a coating disposed on the substrate, The cutting tool comprises: Rake face, a flank surface connected to the rake surface; and a cutting edge formed by a boundary portion between the rake face and the flank face, the coating includes a TiAlCeN layer; The TiAlCeN layer is a first TiAlCeN layer located on the rake face or the flank face; a second TiAlCeN layer located on the cutting edge; The composition of the first TiAlCeN layer is Ti x1 Al y1 Ce z1 N, The composition of the second TiAlCeN layer is Ti x2 Al y2 Ce z2 N, where: x1+y1+z1=1, x2+y2+z2=1, 0.300 <y1≦0.700、 0.300 <y2≦0.700、 0.010 <z1≦0.100、 0 <z2≦0.090、および、 A cutting tool, wherein z1-z2≧0.010.

[0025] The cutting tool of the present disclosure can have a long tool life even under machining conditions where the load on the cutting edge is large. The reasons are presumed to be as follows (i) to (iii).

[0026] (i) In the cutting tool of the present embodiment, the composition of the first TiAlCeN layer located on the rake face or the flank face is Ti x1 Al y1 Ce z1 N, where x1 + y1 + z1 = 1, 0.300 < y1 ≤ 0.700, and 0.010 < z1 ≤ 0.100. That is, the first TiAlCeN layer contains more than 30 atomic% and at most 70 atomic% of Al with respect to the total number of atoms of titanium (Ti), aluminum (Al), and cerium (Ce), and contains more than 1.0 atomic% and at most 10.0 atomic% of Ce. Thereby, the first TiAlCeN layer can have excellent heat resistance and wear resistance. Therefore, when the first TiAlCeN layer is located on the rake face, the excellent heat resistance of the first TiAlCeN layer suppresses plastic deformation of the base material and oxidation of the coating, and thermal wear of the rake face is suppressed. Further, when the first TiAlCeN layer is located on the flank face, the excellent wear resistance of the first TiAlCeN layer suppresses mechanical wear of the flank face, and the excellent heat resistance of the first TiAlCeN layer suppresses the progress of thermal cracks.

[0027] (ii) In the cutting tool of the present embodiment, the ratio z1 of the number of cerium atoms to the total number of Ti, Al, and Ce atoms in the first TiAlCeN layer and the ratio z2 of the number of cerium atoms to the total number of Ti, Al, and Ce atoms in the second TiAlCeN layer satisfy the relationship z1 - z2 ≥ 0.010. For this reason, the second TiAlCeN layer has higher toughness than the first TiAlCeN layer. Therefore, the second TiAlCeN layer can suppress the occurrence of microchipping at the cutting edge. Furthermore, the progress of thermal cracks generated starting from the cutting edge can be suppressed.

[0028] (iii) As described above, the cutting tool of the present embodiment has a well-balanced improvement in the wear resistance of the rake face or flank face and the fracture resistance of the cutting edge, and therefore the cutting tool of the present disclosure can have a long tool life even under machining conditions that place a heavy load on the cutting edge.

[0029] <Cutting tool structure> 1, the cutting tool 1 of this embodiment has a surface including an upper surface, a lower surface, and four side surfaces, and has an overall rectangular prism shape that is slightly thin in the vertical direction. Furthermore, the cutting tool 1 has a through-hole that penetrates the upper and lower surfaces, and at the boundaries between the four side surfaces of the cutting tool 1, adjacent side surfaces are connected by arc surfaces.

[0030] In the cutting tool 1 of this embodiment, the upper and lower surfaces form the rake face 11, and the four side surfaces (and the arc surfaces connecting these) form the flank 12. The boundary portion between the rake face 11 and the flank 12 functions as a cutting edge 13. In other words, the surfaces of the cutting tool 1 of this embodiment (the upper and lower surfaces, the four side surfaces, the arc surfaces connecting these side surfaces, and the inner peripheral surface of the through hole) include the rake face 11, the flank 12 connected to the rake face, and the cutting edge 13 consisting of the boundary portion between the rake face 11 and the flank 12.

[0031] The boundary portion between the rake face 11 and the flank 12, i.e., the cutting edge 13, means "the combined portion of the ridge line E that forms the boundary between the rake face 11 and the flank 12 and the portions of the rake face 11 and the flank 12 that are near the ridge line E." The "portions of the rake face 11 and the flank 12 that are near the ridge line E" are determined by the shape of the cutting edge 13 of the cutting tool 1. Below, we will explain the cases where the cutting tool 1 is a tool with a sharp edge shape, a tool with a honed shape that has been honed, and a tool with a negative land shape that has been negative land.

[0032] 2 and 3 show a cutting tool 1 with a sharp edge shape. In such a cutting tool 1 with a sharp edge shape, "portions of the rake face 11 and flank face 12 that are near the ridge line E" are defined as the region where the distance (linear distance) D from the ridge line E is 50 μm or less (the region indicated by dotted hatching in FIG. 3). Therefore, the cutting edge 13 of the cutting tool 1 with a sharp edge shape is the portion that corresponds to the region indicated by dotted hatching in FIG. 3.

[0033] 4 and 5 show a honed-shaped cutting tool 1 that has been honed. In addition to each part of the cutting tool 1, Figures 4 and 5 also show an imaginary plane R including the rake face 11, an imaginary plane F including the flank face 12, an imaginary ridge line EE formed by the intersection of the imaginary planes R and F, an imaginary boundary line ER that marks the boundary between the rake face 11 and the imaginary plane R, and an imaginary boundary line EF that marks the boundary between the flank face 12 and the imaginary plane F. Note that with respect to the honed-shaped cutting tool 1, the above-mentioned "ridge line E" should be read as "imaginary ridge line EE."

[0034] In such a honed cutting tool 1, "the portion of the rake face 11 and flank 12 near the imaginary ridge line EE" is defined as the region between the imaginary boundary lines ER and EF (the region indicated by dotted hatching in FIG. 5). Therefore, the cutting edge 13 in the honed cutting tool 1 is the portion corresponding to the region indicated by dotted hatching in FIG. 5.

[0035] 6 and 7 show a cutting tool 1 having a negative land shape that has been subjected to negative land machining. In addition to each part of the cutting tool 1, Figures 6 and 7 also show an imaginary plane R including the rake face 11, an imaginary plane F including the flank face 12, an imaginary ridge line EE formed by the intersection of the imaginary planes R and F, an imaginary boundary line ER that defines the boundary between the rake face 11 and the imaginary plane R, and an imaginary boundary line EF that defines the boundary between the flank face 12 and the imaginary plane F. It should be noted that, in the case of the cutting tool 1 having a negative land shape, the above-mentioned "ridge line E" is also referred to as "imaginary ridge line EE."

[0036] In such a cutting tool 1 having a negative land shape, "the portion of the rake face 11 and the flank face 12 near the imaginary ridge line EE" is defined as the region between the imaginary boundary lines ER and EF (the region indicated by dotted hatching in FIG. 7). Therefore, the cutting edge 13 in the cutting tool 1 having a negative land shape is the portion corresponding to the region indicated by dotted hatching in FIG. 7.

[0037] 8 and 9 show a cutting tool 1 having a shape that has been machined by combining honing and a negative land. In addition to each part of the cutting tool 1, FIGS. 8 and 9 also show an imaginary plane R including the rake face 11, an imaginary plane F including the flank face 12, an imaginary ridge line EE formed by the intersection of the imaginary planes R and F, an imaginary boundary line ER defining the boundary between the rake face 11 and the imaginary plane R, and an imaginary boundary line EF defining the boundary between the flank face 12 and the imaginary plane F. Note that, even in the case of a cutting tool 1 having a negative land shape, the above-mentioned "ridge line E" is replaced with "imaginary ridge line EE." Note that the imaginary plane R is the plane of the rake face 11 that includes the plane closest to the cutting edge 13.

[0038] In the cutting tool 1 having such a shape, "the portion of the rake face 11 and the flank face 12 near the imaginary ridge line EE" is defined as the region between the imaginary boundary line ER and the imaginary boundary line EF (the region indicated by dotted hatching in Fig. 8). Therefore, the cutting edge 13 of the cutting tool 1 corresponds to the region indicated by dotted hatching in Fig. 8.

[0039] FIG. 1 shows a cutting tool 1 as an indexable cutting tip for turning, but the cutting tool 1 is not limited to this and examples include drills, end mills, indexable cutting tips for drills, indexable cutting tips for end mills, indexable cutting tips for milling, metal saws, gear cutting tools, reamers, taps, etc.

[0040] Furthermore, when the cutting tool 1 is an indexable cutting tip or the like, the cutting tool 1 may have or may not have a chip breaker, and the cutting edge 13 may have any of the following shapes: a sharp edge (the ridge where the rake face and flank intersect) (see Figures 1 to 3), a honed edge (a sharp edge with a radius) (see Figures 4 and 5), a negative land (chamfered) (see Figures 6 and 7), or a combination of honing and negative land (see Figures 8 and 9).

[0041] As shown in Fig. 2, the cutting tool 1 includes a substrate 2 and a coating 3 disposed on the substrate 2. The coating 3 may be disposed on a portion of the surface of the substrate 2, or may be disposed on the entire surface of the substrate 2. When the coating 3 is disposed on a portion of the surface of the substrate 2, the portion of the surface of the substrate 2 includes the entire area within a distance (straight-line distance) D of 200 µm from the ridge line E or the virtual ridge line EE. As long as the effects of the present disclosure are achieved, partial variations in the configuration of the coating 3 do not depart from the scope of the present embodiment.

[0042] <Base material> As shown in FIGS. 2 and 3, the substrate 2 of this embodiment has a rake face 2a and a flank 2b. The boundary between the rake face 2a and the flank 2b forms the cutting edge 2c. The "boundary between the rake face 2a and the flank 2b" refers to the "combination of the ridgeline forming the boundary between the rake face 2a and the flank 2b and the portions of the rake face 2a and the flank 2b that are near the ridgeline," similar to the "boundary between the rake face 11 and the flank 12" described above. The "portion near the ridgeline of the rake face 2a and the flank 2b" is defined as described above depending on whether the shape of the cutting edge 13 of the cutting tool 1 is a sharp edge shape, a honed shape, or a negative land shape.

[0043] Any known substrate of this type can be used as the substrate 2. For example, cemented carbide (WC-based cemented carbide, cemented carbide containing WC and Co, cemented carbide containing Ti, Ta, Nb, or other carbonitrides), cermet (mainly composed of TiC, TiN, TiCN, or other materials), high-speed steel, ceramics (titanium carbide, silicon carbide, silicon nitride, aluminum nitride, aluminum oxide, or other materials), cubic boron nitride sintered body, or diamond sintered body are preferred. Among these various substrates, WC-based cemented carbide and cermet (particularly TiCN-based cermet) are particularly preferred. This is because these substrates have an excellent balance between hardness and strength, especially at high temperatures, and offer excellent properties as substrates for cutting tools.

[0044] <Coating> The coating 3 of the first embodiment has a TiAlCeN layer. The coating 3 of the present embodiment may or may not include other layers, so long as it has a TiAlCeN layer. Examples of other layers include a first layer. As shown in FIG. 10 , the first layer 31 can be provided between the substrate 2 and the TiAlCeN layer 30. In this case, the first layer 31 corresponds to the underlayer 32. The first layer 31 can be provided on the outermost surface of the coating 3. In this case, the first layer 31 corresponds to the surface layer 33. The coating can include one or both of the underlayer 32 and the surface layer 33. Details of the first layer will be described later.

[0045] The layer structure of the coating 3 does not need to be uniform over the entire coating 20, and the layer structure may vary in parts.

[0046] The thickness of the coating 3 is preferably 0.5 μm or more and 15 μm or less. If the thickness of the coating is less than 0.5 μm, the tool life tends to be insufficient. If the thickness of the coating is more than 15 μm, stress is generated within the coating during machining, making it more likely to peel or break. The thickness of the coating is more preferably 1.0 μm or more and 12.0 μm or less, and even more preferably 3.0 μm or more and 7.0 μm or less. The method for measuring the thickness of the coating will be described later.

[0047] <TiAlCeN layer> The TiAlCeN layer of this embodiment has a first TiAlCeN layer located on the rake face 11 or the flank face 12, and a second TiAlCeN layer located on the cutting edge 13. That is, in one TiAlCeN layer, there are regions composed of the first TiAlCeN layer and regions composed of the second TiAlCeN layer.

[0048] ≪Composition≫ The composition of the first TiAlCeN layer is Ti x1 Al y1 Ce z1 N, and the composition of the second TiAlCeN layer is Ti x2 Al y2 Ce z2 N. Here, x1, y1, z1, x2, y2, and z2 satisfy the following (1) to (7). (1) x1 + y1 + z1 = 1 (2) x2 + y2 + z2 = 1 (3) 0.300 < y1 ≤ 0.700 (4) 0.300 < y2 ≤ 0.700 (5) 0.010 < z1 ≤ 0.100 (6) 0 < z2 ≤ 0.090 (7) z1 - z2 ≥ 0.010

[0049] The lower limit of y1 above is more than 0.300, preferably 0.310 or more, preferably 0.320 or more, preferably 0.350 or more, and more preferably 0.400 or more, from the viewpoint of improving the heat resistance of the first TiAlCeN layer. The upper limit of y1 above is 0.700 or less, preferably 0.650 or less, preferably 0.630 or less, and more preferably 0.600 or less, from the viewpoint of improving the hardness of the first TiAlCeN layer. The above y1 is more than 0.300 and 0.700 or less, preferably 0.350 or more and 0.650 or less, and still more preferably 0.400 or more and 0.600 or less.

[0050] From the viewpoint of improving the wear resistance of the first TiAlCeN layer, the lower limit of z1 is more than 0.010, preferably 0.011 or more, preferably 0.015 or more, and more preferably 0.020 or more. From the viewpoint of improving the chipping resistance of the first TiAlCeN layer, the upper limit of z1 is 0.100 or less, preferably 0.080 or less, preferably 0.065 or less, preferably 0.060 or less, preferably 0.050 or less, and more preferably 0.030 or less. z1 is more than 0.010 but not more than 0.100, preferably 0.015 or more but not more than 0.050, and more preferably 0.020 or more but not more than 0.030.

[0051] The lower limit of y2 is more than 0.300, preferably 0.350 or more, and more preferably 0.400 or more, from the viewpoint of improving the heat resistance of the second TiAlCeN layer. The upper limit of y2 is 0.700 or less, preferably 0.650 or less, and more preferably 0.600 or less, from the viewpoint of improving the hardness of the second TiAlCeN layer. The above y2 is more than 0.300 and 0.700 or less, preferably 0.350 or more and 0.650 or less, and more preferably 0.400 or more and 0.600 or less.

[0052] From the viewpoint of improving the wear resistance of the second TiAlCeN layer, the lower limit of z2 is more than 0, and is preferably 0.001 or more, preferably 0.002 or more, preferably 0.005 or more, and more preferably 0.010 or more. From the viewpoint of improving the chipping resistance of the second TiAlCeN layer, the upper limit of z2 is 0.090 or less, preferably 0.060 or less, preferably 0.040 or less, and more preferably 0.020 or less. The z2 is more than 0 and 0.090 or less, preferably 0.005 or more and 0.040 or less, and more preferably 0.010 or more and 0.020 or less.

[0053] From the viewpoint of improving the wear resistance and chipping resistance of the TiAlCeN layer in a well-balanced manner, the lower limit of z1-z2 is 0.010 or more, preferably 0.013 or more, preferably 0.015 or more, and preferably 0.020 or more. From the viewpoint of improving the peeling resistance of the TiAlCeN layer, the upper limit of z1-z2 is preferably 0.099 or less, preferably 0.090 or less, preferably 0.050 or less, preferably 0.030 or less, and preferably 0.025 or less. z1-z2 is preferably 0.010 or more and 0.090 or less, more preferably 0.013 or more and 0.050 or less, and even more preferably 0.015 or more and 0.030 or less.

[0054] The above x1 can be calculated by x1=1-y1-z1, and the above x2 can be calculated by x2=1-y2-z2.

[0055] The above x1, y1, z1, x2, y2, and z2 can be determined by measuring the composition of each region (cutting edge region, rake face region, and flank face region) of the TiAlCeN layer using a scanning electron microscope equipped with an energy dispersive X-ray spectrometer (SEM-EDS). A specific measurement method will be described below.

[0056] (A1) A measurement sample is obtained by cutting the cutting tool 1 so as to expose a cross section along the thickness direction of the coating 3. The cutting position is determined as follows, taking into account the actual usage conditions of the cutting tool.

[0057] 11 and 12 are diagrams illustrating the cutting position of the cutting tool. When the cutting tool 1 is used to cut a workpiece with the cutting edge 13 of a corner portion (a portion with an apex angle that forms an arc), the cutting is performed so that a cross section that includes a line L1 that bisects the corner portion and that runs along the thickness direction of the coating 3 is exposed, as shown in FIG. 11. On the other hand, when the cutting tool 1 is used to cut a workpiece with the cutting edge 13 of a straight portion (a portion that forms a straight line), the cutting is performed so that a cross section that includes a line L2 that is perpendicular to the cutting edge of the straight portion and that runs along the thickness direction of the coating 3 is exposed, as shown in FIG. 12. If necessary, the exposed cut surface is polished to make it smooth.

[0058] (B1) The above cut surface is observed at 5000x magnification using SEM-EDS, and three rectangular measurement fields of view, each measuring 15 μm or more in the thickness direction of the coating and 15 μm or more in the direction perpendicular to the thickness direction, are set so as to include the first TiAlCeN layer located on the rake face or flank face. The thickness direction of the measurement fields of view is set so as to include the entire thickness of the first TiAlCeN layer.

[0059] When the measurement field of view is set to include the first TiAlCeN layer located on the rake face, the measurement field of view is set so that the first TiAlCeN layer is located on the rake face at a distance of 100 μm to 200 μm from the ridge line E or the virtual ridge line EE. When the measurement field of view is set to include the first TiAlCeN layer located on the flank face, the measurement field of view is set so that the first TiAlCeN layer is located on the flank face at a distance of 100 μm to 200 μm from the ridge line E or the virtual ridge line EE.

[0060] As shown in Fig. 13, the three measurement fields are set so that the sides of each measurement field are in contact with each other in the thickness direction (the direction indicated by arrow T in Fig. 13) and so that the measurement fields are continuous. The measurement fields may partially overlap (the overlapping parts are indicated by diagonal lines in Fig. 13). In this case, the measurement fields are set so that the length of the overlapping parts of the sides in the direction perpendicular to the thickness direction (the direction indicated by arrow H in Fig. 13) is 2 µm or less.

[0061] (C1) In each of the three measurement fields, the region of the first TiAlCeN layer is identified. Specifically, element mapping is performed by SEM-EDS for each measurement field to identify the layer containing Ti, Al, and Ce. The identified layer corresponds to the first TiAlCeN layer.

[0062] (D1) For each of the three measurement fields, the composition ratios of Al, Ti, and Ce in the first TiAlCeN layer are analyzed, and the ratio x1 of Ti, the ratio y1 of Al, and the ratio z1 of Ce relative to the total number of Al, Ti, and Ce atoms are calculated. The average value of x1 for the three measurement fields is the composition Ti of the first TiAlCeN layer of this embodiment. x1 Al y1 Ce z1 The average value of y1 in the three measurement fields corresponds to the composition TiAlCeN of the first TiAlCeN layer of this embodiment. x1 Al y1 Ce z1 The average value of z1 in the three measurement fields corresponds to the composition TiAlCeN of the first TiAlCeN layer of this embodiment. x1 Al y1 Ce z1 This corresponds to z1 in N.

[0063] The composition of the second TiAlCeN layer located at the cutting edge is Ti x2 Al y2 Ce z2x2, y2, and z2 in N are also measured in the same manner as x1, y1, and z1 above, except that the position of the measurement field is set to include the second TiAlCeN layer located on the cutting edge. The measurement field is set so that the second TiAlCeN layer included in the measurement field is the second TiAlCeN layer located on the cutting edge at a distance of 50 μm or less from the ridge line E or the virtual ridge line EE.

[0064] The above-mentioned SEM-EDS analysis can be performed using, for example, a scanning electron microscope (S-3400N, manufactured by Hitachi High-Technologies Corporation) under the following conditions. Accelerating voltage: 15 kV Process time: 5 Spectral range: 0 to 20 keV Number of channels: 1K Number of frames: 150 X-ray take-off angle: 30°.

[0065] It has been confirmed that as long as measurements are made using the same cutting tool, there is no variation in the measurement results even if the measurement location is selected arbitrarily.

[0066] The composition of the first TiAlCeN layer in this embodiment is Ti x1 Al y1 Ce z1 In N, the total number of Ti, Al and Ce atoms, A M1 Atomic number of N N1 Ratio A N1 / A M1 The composition Ti of the second TiAlCeN layer of this embodiment is necessarily in the range of 0.8 to 1.2. x2 Al y2 Ce z2 In N, the total number of Ti, Al and Ce atoms, A M2 Atomic number of N N2 Ratio A N2 / A M2 is necessarily in the range of 0.8 to 1.2 in terms of manufacturing.

[0067] Above ratio A N1 / A M1 and ratio AN2 / A M2 can be measured by the Rutherford backscattering (RBS) method. N1 / A M1 and ratio A N2 / A M2 It has been confirmed that the effects of the present disclosure are not impaired if the value is within the above range.

[0068] <Thickness> In this embodiment, the thickness of the TiAlCeN layer is preferably 0.5 μm or more and 15 μm or less. If the thickness of the TiAlCeN layer is less than 0.5 μm, it is difficult to obtain the effect of improving the wear resistance and chipping resistance of the TiAlCeN layer, and the tool life tends to be insufficient. If the thickness of the TiAlCeN layer exceeds 15 μm, stress is generated in the TiAlCeN layer during machining, making it more likely to peel or break. The thickness of the TiAlCeN layer is more preferably 1 μm or more and 12 μm or less, and even more preferably 3 μm or more and 7 μm or less. The thickness of the TiAlCeN layer is measured as follows.

[0069] (A2) Using the same method as that described in (A1) of the method for measuring the composition of the first TiAlCeN layer, the cutting tool is cut so that a cross section along the thickness direction of the coating is exposed, to obtain a measurement sample.

[0070] (B2) The cross section is observed at 1500x magnification using a scanning electron microscope (S-3400N, manufactured by Hitachi High-Technologies Corporation), and the thickness of the TiAlCeN layer is measured at three arbitrary locations on each of the rake face and flank face along the normal direction of the substrate surface. The arithmetic mean of these measurements corresponds to the "TiAlCeN layer thickness." The SEM measurement conditions are the same as those described in (D1) of the first method for measuring the composition of the TiAlCeN layer.

[0071] It has been confirmed that as long as measurements are made using the same cutting tool, there is no variation in the measurement results even if the measurement location is selected arbitrarily.

[0072] In this embodiment, the thickness of the coating and the thickness of the first layer are also measured using the same procedure as above. It has been confirmed that, as long as the same cutting tool is used to measure these thicknesses, there is no variation in the measurement results even if the measurement location is arbitrarily selected.

[0073] <Crystal structure> In this embodiment, the TiAlCeN layer preferably has a cubic crystal structure. This allows the TiAlCeN layer to have high hardness and excellent wear resistance. Here, "the TiAlCeN layer has a cubic crystal structure" means that when the X-ray diffraction spectrum of the TiAlCeN layer is measured, peaks derived from the cubic crystal structure are observed, and peaks derived from crystal structures other than the cubic crystal structure (e.g., wurtzite crystal structure) are not observed (i.e., below the detection limit). Such an X-ray diffraction spectrum is measured as follows.

[0074] A flat portion of the tool flank is cut out and fixed to a holder to prepare a sample. The sample is then polished as necessary to smooth the surface to be measured. If any other layer is formed on the TiAlCeN layer, that layer is removed by polishing or other means, and the surface of the TiAlCeN layer is then smoothed. Next, an X-ray diffractometer (XRD) is used to perform X-ray diffraction on the TiAlCeN layer, and an X-ray diffraction spectrum is obtained.

[0075] The above-mentioned X-ray diffraction can be measured, for example, using an X-ray diffractometer (SmartLab (registered trademark), manufactured by Rigaku Corporation) under the following conditions. Diffraction method: θ-2θ method X-ray source: Cu-Kα ray (1.541862Å) Detector: D / Tex Ultra250 Tube voltage: 45kV Tube current: 200mA Scan speed: 20° / min Scanning range: 15~85° Slit: 2.0mm.

[0076] ≪First layer≫ The coating 3 of this embodiment further includes a first layer, which preferably comprises at least one element selected from a first group consisting of Group 4, Group 5, and Group 6 elements, aluminum, and silicon, or a first compound comprising at least one element selected from Group 1 and at least one element selected from Group 2 consisting of carbon, nitrogen, oxygen, and boron. Elements in Group 4 of the periodic table include titanium (Ti), zirconium (Zr), and hafnium (Hf). Elements in Group 5 of the periodic table include vanadium (V), niobium (Nb), and tantalum (Ta). Elements in Group 6 of the periodic table include chromium (Cr), molybdenum (Mo), and tungsten (W).

[0077] The first group preferably consists of titanium, chromium, aluminum, and silicon. That is, the first layer preferably consists of a first compound consisting of at least one element selected from the group consisting of titanium, chromium, aluminum, and silicon, or at least one element selected from the group consisting of titanium, chromium, aluminum, and silicon and at least one element selected from the second group consisting of carbon, nitrogen, oxygen, and boron. This further improves tool life.

[0078] Examples of the first compound include TiAlN, TiAlSiCN, TiAlSiON, TiAlSiN, TiCrSiN, TiAlCrSiN, AlCrN, AlCrO, AlCrSiN, TiZrN, TiAlMoN, TiAlNbN, TiSiN, AlCrTaN, AlTiVN, TiB2, TiCrHfN, CrSiWN, TiAlCN, TiSiCN, AlZrON, AlCrCN, AlHfN, CrSiBON, CrAlBN, TiAlWN, AlCrMoCN, TiAlBN, TiAlCrSiBCNO, ZrN, ZrB2, ZrCN, CrSiBN, and AlCrBN.

[0079] The first layer can be provided between the substrate and the TiAlCeN layer. In this case, the first layer corresponds to an underlayer. The underlayer can improve adhesion between the substrate and the coating, and also improve the wear resistance of the coating. When the first layer is an underlayer, the first layer is preferably made of TiAlN, TiN, or AlCrN. In this case, the thickness of the first layer is preferably 0.2 μm or more and 10 μm or less, and more preferably 1 μm or more and 5 μm or less.

[0080] The first layer can be formed on the outermost surface of the coating. In this case, the first layer corresponds to a surface layer. The surface layer can improve the thermal crack resistance and wear resistance of the coating. When the first layer is a surface layer, the first layer is preferably made of TiCN, TiAlBN, TiAlSiN, or TiN. In this case, the thickness of the first layer is preferably 0.2 μm or more and 10 μm or less, and more preferably 1 μm or more and 5 μm or less.

[0081] [Embodiment 2: Cutting tool (2)] A cutting tool according to one embodiment of the present disclosure (hereinafter also referred to as "Embodiment 2") can have the same configuration as Embodiment 1, except that it includes a multilayer structure in which TiAlCeN layers and first layers are alternately stacked. Therefore, the multilayer structure will be described below.

[0082] ≪Multilayer structure≫ 14, the coating 3 of this embodiment preferably includes a multilayer structure in which TiAlCeN layers 30 and first layers 31 are alternately stacked. This makes it possible to suppress the propagation of cracks from the surface of the coating that occur near the interface between the TiAlCeN layer and the first layer during use of the cutting tool. This improves the tool life of the cutting tool.

[0083] The multilayer structure may include a first multilayer structure in which first TiAlCeN layers and the first layer are alternately stacked, and a second multilayer structure in which second TiAlCeN layers and the first layer are alternately stacked, The first multilayer structure is located on the flank or rake face, and the second multilayer structure is located on the cutting edge.

[0084] The number of stacked TiAlCeN layers and first layers is not particularly limited, as long as the multilayer structure includes at least one TiAlCeN layer and at least one first layer. The number of stacked layers refers to the total number of TiAlCeN layers and first layers included in the multilayer structure. The number of stacked layers is preferably 10 to 5,000, more preferably 200 to 5,000, more preferably 400 to 2,000, and even more preferably 500 to 1,000. In the multilayer structure, the layer closest to the substrate may be either the TiAlCeN layer or the first layer. In addition, in the multilayer structure, the layer farthest from the substrate may be either the TiAlCeN layer or the first layer. Here, the TiAlCeN layer refers to the first TiAlCeN layer or the second TiAlCeN layer.

[0085] The thickness of the multilayer structure is preferably 0.5 μm or more and 15 μm or less, more preferably 1 μm or more and 12 μm or less. The thickness of the multilayer structure is measured by the method for measuring the thickness of a TiAlCeN layer described in embodiment 1, except that the multilayer structure is used as the measurement target.

[0086] It has been confirmed that as long as measurements are made using the same cutting tool, there is no variation in the measurement results even if the measurement location is selected arbitrarily.

[0087] In the above multilayer structure, the TiAlCeN layer and the first layer each preferably have a thickness of 2 nm to 50 nm. By alternately repeating such thin layers, crack propagation can be suppressed, and delamination can also be suppressed. If the thickness of each of the TiAlCeN layer and the first layer is less than 2 nm, the effect of suppressing crack propagation may be reduced. Furthermore, if the thickness of each of the TiAlCeN layer and the first layer is more than 50 nm, the effect of suppressing delamination may be reduced.

[0088] In the above multilayer structure, the thickness of each of the TiAlCeN layer and the first layer is preferably 2 nm or more and 50 nm or less, more preferably 4 nm or more and 40 nm or less, and even more preferably 5 nm or more and 30 nm or less.

[0089] The thickness of each of the TiAlCeN layer and the first layer in the above multilayer structure was measured as follows.

[0090] (A3) Using the same method as that described in (A1) of the method for measuring the composition of the first TiAlCeN layer, the cutting tool is cut so that a cross section along the thickness direction of the coating is exposed, to obtain a measurement sample.

[0091] (B3) The above cross section is observed at approximately 1,000,000 magnification using a scanning electron microscope (S-3400N, manufactured by Hitachi High-Technologies Corporation). The thickness of one TiAlCeN layer is measured at three locations. The arithmetic mean value of the thicknesses at the three locations is calculated, and this arithmetic mean value is defined as the thickness of the TiAlCeN layer. The thickness of one first layer is measured at three locations. The arithmetic mean value of the thicknesses at the three locations is calculated, and this arithmetic mean value is defined as the thickness of the first layer.

[0092] For each of the three different TiAlCeN layers, the thickness of the TiAlCeN layer is measured using the above procedure. The arithmetic mean value of the thicknesses of the three TiAlCeN layers is determined. This arithmetic mean value is used as the thickness of the TiAlCeN layer in the multilayer structure. For each of the three different first layers, the thickness of the first layer is measured using the above procedure. The arithmetic mean value of the thicknesses of the three first layers is determined. This arithmetic mean value is used as the thickness of the first layer in the multilayer structure.

[0093] It has been confirmed that as long as measurements are made using the same cutting tool, there is no variation in the measurement results even if the measurement location is selected arbitrarily.

[0094] The composition of the TiAlCeN layer in the multilayer structure is measured by the following procedure: Three measurement fields are set in the same manner as steps (A1) to (D1) of the method for measuring the composition (x1, y1, z1, x2, y2, z2) of the TiAlCeN layer described in embodiment 1.

[0095] In each measurement field, five layers of the first TiAlCeN layer and five layers of the second TiAlCeN layer are arbitrarily selected and measured, and the average composition of the five layers of each of the first TiAlCeN layer and the second TiAlCeN layer is determined.

[0096] The average composition of the five first TiAlCeN layers is defined as the composition of the first TiAlCeN layer in the measurement field. The average composition of the first TiAlCeN layers in the three measurement fields is defined as the composition of the first TiAlCeN layer in the multilayer structure of this embodiment.

[0097] The average composition of the five second TiAlCeN layers is defined as the composition of the second TiAlCeN layer in the measurement field. The average composition of the second TiAlCeN layers in the three measurement fields is defined as the composition of the second TiAlCeN layer in the multilayer structure of this embodiment.

[0098] It has been confirmed that as long as measurements are made using the same cutting tool, there is no variation in the measurement results even if the measurement location is selected arbitrarily.

[0099] [Embodiment 3: Method for manufacturing a cutting tool] In embodiment 3, a method for manufacturing the cutting tool of embodiment 1 or embodiment 2 is described. The manufacturing method can include a step of preparing a substrate and a step of forming a coating on the substrate. Details of each step are described below.

[0100] <Process of preparing substrate> In the step of preparing a substrate, a substrate 2 is prepared. The substrate 2 may be the substrate described in embodiment 1.

[0101] For example, when a cemented carbide is used as the substrate, a commercially available substrate may be used, or it may be manufactured by a general powder metallurgy method. When manufactured by a general powder metallurgy method, for example, WC powder and Co powder are mixed using a ball mill or the like to obtain a mixed powder. The mixed powder is then dried and molded into a predetermined shape to obtain a green body. The green body is then sintered to obtain a WC-Co based cemented carbide (sintered body). The sintered body is then subjected to a predetermined cutting edge processing such as honing, thereby producing a substrate made of a WC-Co based cemented carbide. Any substrate other than those mentioned above can also be prepared as long as it is a conventionally known substrate of this type.

[0102] <<Coating Forming Process>> In the step of forming a coating, the coating 3 is formed on the substrate 2. In this embodiment, the coating 3 can be formed by a physical vapor deposition (PVD) method. Specific examples of the PVD method include an arc ion plating (AIP) method, a balanced magnetron sputtering (BMS) method, and an unbalanced magnetron sputtering (UBMS) method. In this embodiment, it is preferable to use arc ion plating.

[0103] In the AIP method, an arc discharge is generated using a target material as a cathode. This causes the target material to evaporate and ionize. The ions are then deposited on the surface of a substrate 2 to which a negative bias voltage is applied. The AIP method is excellent in terms of the ionization rate of the target material. The specific film formation method is as follows.

[0104] A target material and a substrate are placed in the chamber of the deposition system. The substrate is held in a rotatable substrate holder. Depending on the composition of the coating to be formed, alloy targets with varying particle sizes of Ti, Al, Ce, etc., or multiple targets with different compositions can be used. The composition of the coating can also be changed by adjusting the reaction gas pressure and / or the rotation speed of the substrate holder.

[0105] Subsequently, the surface of the substrate 2 is cleaned by ion bombardment treatment using Ar ions. The ion bombardment treatment can be carried out under conventionally known conditions.

[0106] When the coating includes a first layer as a base layer, the first layer is formed on the surface of the substrate 2. For example, a TiAlN layer, a TiN layer, or an AlCrN layer is formed on the surface of the substrate 2. The first layer can be formed by a conventionally known method.

[0107] Next, after placing the shielding material 50 in the chamber of the film formation device, nitrogen gas is introduced into the chamber, and a TiAlCeN layer is formed on the substrate 2 while rotating the substrate holder that holds the substrate 2. At this time, the positional relationship between the target material, the substrate, and the shielding material is adjusted. This positional relationship will be explained using FIGS. 15 and 16.

[0108] 15, the substrate 2 is disposed so that its flank 12 faces the target material 51. In addition, the shielding material 50 is disposed so that it faces the rake face 11 of the substrate 2.

[0109] By arranging the target material 51, the substrate 2, and the shielding material 50 in the above-described positional relationship, the presence of the shielding material 50 makes it more difficult for a film to be formed on the rake face 11 and the cutting edge 13 than on the flank face 12. Furthermore, because Ce ions have a large ionic radius, they are easily trapped by the shielding material 50. Therefore, the amount of Ce that reaches the rake face 11 and the cutting edge 13 is smaller than the amount of Ce that reaches the flank face 12. Therefore, the Ce content (atomic %) in the TiAlCeN layer formed on the rake face 11 and the cutting edge 13 is smaller than the Ce content (atomic %) in the TiAlCeN layer formed on the flank face 12.

[0110] 15, the TiAlCeN layer can have different compositions on the flank 12 and the cutting edge 13. Furthermore, by employing appropriate targets and forming conditions and providing the shielding material in the above-described positional relationship, the ratio z1 of Ce to the total number of Ti, Al, and Ce atoms in the TiAlCeN layer located on the flank 12 can be made larger than the ratio z2 of Ce to the total number of Ti, Al, and Ce atoms in the TiAlCeN layer located on the cutting edge 13 by 0.010 or more.

[0111] 16, the substrate 2 is disposed so that its rake face 11 faces the target material 51. In addition, the shielding material 50 is disposed so that it faces the flank face 12 of the substrate 2.

[0112] By arranging the target material 51, the substrate 2, and the shielding material 50 in the above positional relationship, the presence of the shielding material 50 makes it more difficult for a film to be formed on the flank 12 and the cutting edge 13 than on the rake face 11. Furthermore, because Ce ions have a large ionic radius, they are easily trapped by the shielding material 50. Therefore, the amount of Ce that reaches the flank 12 and the cutting edge 13 is smaller than the amount of Ce that reaches the rake face 11. Therefore, the Ce content (atomic %) in the TiAlCeN layer formed on the flank 12 and the cutting edge 13 is smaller than the Ce content (atomic %) in the TiAlCeN layer formed on the rake face 11.

[0113] 16, the TiAlCeN layer can have different compositions on the rake face 11 and the cutting edge 13. Furthermore, by adopting appropriate targets and forming conditions and providing the shielding material in the above-mentioned positional relationship, the ratio z1 of Ce to the total number of Ti, Al, and Ce atoms in the TiAlCeN layer located on the rake face 11 can be made larger than the ratio z2 of Ce to the total number of Ti, Al, and Ce atoms in the TiAlCeN layer located on the cutting edge 13 by 0.010 or more.

[0114] A stainless steel plate can be used as the shielding material 50. The distance between the substrate 2 and the shielding material 50 can be set to, for example, 1 mm or more and 6 mm or less.

[0115] The conditions for forming the TiAlCeN layer can be as follows. Base material temperature: 450~600℃ Bias voltage: -30 to -100V Arc current: 100~200A Reaction gas pressure: 3 to 6 Pa

[0116] A multilayer structure in which TiAlCeN layers and the first layer are alternately stacked can be formed by placing a target for depositing the TiAlCeN layer and a target for depositing the first layer in a chamber and setting the rotation frequency of the rotating holder to, for example, 2 to 5 rpm.

[0117] Next, if the coating includes a first layer as a surface layer, the first layer is formed on the surface of the TiAlCeN layer. For example, a TiCN layer, a TiAlBN layer, a TiAlSiN layer, or a TiN layer is formed on the surface of the TiAlCeN layer. The first layer can be formed by a conventionally known method.

[0118] As described above, the cutting tool 1 including the substrate 2 and the coating 3 provided on the substrate 2 can be manufactured.

[0119] [Appendix 1] 1. A cutting tool comprising a substrate and a coating disposed on the substrate, The cutting tool comprises: Rake face, a flank surface connected to the rake surface; and a cutting edge formed by a boundary portion between the rake face and the flank face, the coating includes a TiAlCeN layer; The TiAlCeN layer is a first TiAlCeN layer located on the rake face or the flank face; a second TiAlCeN layer located on the cutting edge; The composition of the first TiAlCeN layer is Ti x1 Al y1 Ce z1 and The composition of the second TiAlCeN layer is Ti x2 Al y2 Ce z2 and where: x1+y1+z1=1, x2+y2+z2=1, 0.300 <y1≦0.700、 0.300 <y2≦0.700、 0.010 <z1≦0.100、 0 <z2≦0.090、および、 A cutting tool, wherein z1-z2≧0.010.

[0120] [Appendix 2] 2. The cutting tool of claim 1, wherein the TiAlCeN layer has a thickness of 0.5 μm or more and 15 μm or less.

[0121] [Appendix 3] the coating further comprises a first layer; The first layer is at least one element selected from Group 1 consisting of Group 4 elements, Group 5 elements, Group 6 elements, aluminum, and silicon of the periodic table; or 3. The cutting tool according to claim 1 or 2, comprising a first compound comprising at least one element selected from the first group and at least one element selected from a second group consisting of carbon, nitrogen, oxygen, and boron.

[0122] [Appendix 4] 4. The cutting tool of claim 3, wherein the first group consists of titanium, chromium, aluminum, and silicon.

[0123] [Appendix 5] 5. The cutting tool according to claim 1, wherein the coating has a thickness of 0.5 μm or more and 15 μm or less.

[0124] [Appendix 6] 5. The cutting tool of claim 3, wherein the coating includes a multilayer structure in which the TiAlCeN layers and the first layers are alternately stacked. [Example]

[0125] The present embodiment will be described in more detail with reference to examples, although the present embodiment is not limited to these examples.

[0126] [Example 1] <Cutting tool manufacturing> Cutting tools were produced and their tool lives were evaluated as follows. <Process of preparing substrate> As the substrate, a turning tip (model number: CNMG120408N (manufactured by Sumitomo Electric Hardmetal Corp.)) made of P20 cemented carbide as specified in JIS B 4053: 2013 was prepared. The substrate was placed in a substrate holder of an arc ion plating device.

[0127] <<Coating Forming Process>> As target materials, sintered alloys were prepared having the compositions shown in the "TiAlCeN layer" and "first layer" columns under "target material composition" in Table 1. For example, for sample 5, a sintered alloy with an atomic ratio of "Ti:Al:Ce=0.55:0.35:0.10" was prepared as the target material for forming the TiAlCeN layer (hereinafter also referred to as the "TiAlCeN layer target"), and a sintered alloy with an atomic ratio of "Ti:Al:B=0.50:0.45:0.05" was prepared as the target material for forming the first layer (hereinafter also referred to as the "first layer target").

[0128] The target material was placed in the arc evaporation source of an arc ion plating device. When two types of target materials were used, they were placed in different arc evaporation sources. Next, the chamber of the device was evacuated to a vacuum of 0.5 Pa or less, and the substrate temperature was heated to 450°C. Ar gas was then introduced into the chamber to create an Ar atmosphere of 2.5 Pa. In this state, a bias voltage of -800 V was applied to the substrate, and ion bombardment treatment with Ar gas was performed to clean the surface of the substrate.

[0129] (Samples 1 to 3, Samples 7 to 10, Samples 12 to 15) Next, a shielding material was placed in the chamber. The positional relationship between the target material, substrate, and shielding material was as shown in Figure 16. That is, the substrate 2 was placed so that its rake face 11 faced the target material 51. The shielding material 50 was placed so that it faced the flank face 12 of the substrate 2. The distance between the shielding material 50 and the substrate 2 was 3 mm.

[0130] Next, nitrogen gas was introduced into the chamber to create a reaction atmosphere of 3.5 Pa. In this state, an arc current was discharged on the surface of the TiAlCeN layer target, a bias voltage was applied to the substrate, and a TiAlCeN layer was formed on the substrate while the substrate holder holding the substrate was rotated, resulting in a cutting tool. The TiAlCeN layer formation conditions were as follows: Base material temperature: 550℃ Bias voltage: -50V Arc current: 160A Reactant gas pressure: 3.5Pa

[0131] (Sample 1-1, Sample 1-6, Sample 1-7) Using the target for the TiAlCeN layer of each sample, a TiAlCeN layer was formed on the substrate under the same formation conditions (substrate temperature, bias voltage, arc current, reaction gas composition, reaction gas pressure) as those for Sample 1, except that no shielding material was installed, to obtain a cutting tool.

[0132] (Sample 4) Using the target for the TiAlCeN layer of sample 4, a TiAlCeN layer was formed on the substrate under the same formation conditions (substrate temperature, bias voltage, arc current, reactive gas composition, reactive gas pressure, presence of a shielding material, distance between the shielding material and the substrate) as those for sample 1. Next, using the target for the first layer, nitrogen gas and methane gas were introduced from the gas inlet, and the first layer (TiCN layer) was formed as a surface layer on the TiAlCeN layer while rotating the substrate holder, thereby obtaining a cutting tool.

[0133] (Sample 5) Using the target for the TiAlCeN layer of sample 5, a TiAlCeN layer was formed on the substrate under the same formation conditions (substrate temperature, bias voltage, arc current, reactive gas composition, reactive gas pressure, presence of a shielding material, distance between the shielding material and the substrate) as those of sample 1. Next, using the target for the first layer, nitrogen gas was introduced from the gas inlet, and the first layer (TiAlBN layer) was formed as a surface layer on the TiAlCeN layer while rotating the substrate holder, thereby obtaining a cutting tool.

[0134] (Sample 11) Nitrogen gas was introduced into the chamber to create an atmosphere of 3.5 Pa. In this state, an arc current was discharged on the surface of the first layer target, a bias voltage was applied to the substrate side, and the substrate holder was rotated to form the first layer (TiAlN layer) as a base layer on the surface of the substrate.

[0135] Next, using the target for the TiAlCeN layer of sample 11, a TiAlCeN layer was formed on the substrate under the same formation conditions as sample 1 (substrate temperature, bias voltage, arc current, reaction gas composition, reaction gas pressure, presence of a shielding material, distance between the shielding material and the substrate), thereby obtaining a cutting tool.

[0136] (Sample 6) The target for the TiAlCeN layer and the target for the first layer of sample 6 were arranged adjacent to each other in the chamber. That is, the target for the TiAlCeN layer and the target for the first layer were arranged so that when the substrate holder rotated, the positional relationship between the TiAlCeN layer target and the substrate 2 was the same as the positional relationship between the first layer target and the substrate 2.

[0137] Next, a shielding material was placed in the chamber. The positional relationship between the target material, the substrate, and the shielding material was as shown in FIG.

[0138] Next, while rotating the substrate holder at 5 rpm, TiAlCeN layers and AlCrN layers were alternately formed on the substrate under the same formation conditions as Sample 1 (substrate temperature, bias voltage, arc current, reaction gas composition, reaction gas pressure, distance between the shielding material and the substrate), forming a coating with a multilayer structure and obtaining a cutting tool.

[0139] (Sample 1-2, Sample 1-3) A TiAlCeN layer was formed on the substrate under the same formation conditions (substrate temperature, bias voltage, arc current, reaction gas composition, reaction gas pressure) as those for Sample 1, except that a target for the TiAlCeN layer of each sample was used and the distance between the shielding material and the substrate was 0.5 mm, and cutting tools were obtained.

[0140] (Sample 1-4) Using the target for the TiAlCeN layer and the target for the first layer of sample 1-4, a coating having a multilayer structure was formed on the substrate under the same formation conditions (substrate temperature, bias voltage, arc current, reaction gas composition, reaction gas pressure, distance between the shielding material and the substrate) as sample 6, except that no shielding material was installed, and a cutting tool was obtained.

[0141] [Table 1] <Evaluation> <Coating composition> Regarding the TiAlCeN layers of the cutting tools of each sample obtained, the composition of the first TiAlCeN layer located on the rake face was Ti x1 Al y1 Ce z1 N, and the composition of the second TiAlCeN layer located at the cutting edge x2 Al y2 Ce z2 The composition of the first TiAlCeN layer was measured. The specific measurement method is as shown in the first and second embodiments. The results are shown in Table 2 in the "x1", "y1", and "z1" columns of "First TiAlCeN layer (rake face)" and the "x2", "y2", and "z2" columns of "Second TiAlCeN layer". Furthermore, the value of "z1-z2" is also shown in Table 2. It was confirmed that x1+y1+z1=1 and x2+y2+z2=1 in all samples. Furthermore, in all samples, the composition of the first TiAlCeN layer, Ti x1 Al y1 Ce z1 The total number of Ti, Al, and Ce atoms in N is A M1 Atomic number of N N1 Ratio A N1 / A M1 , and the composition of the second TiAlCeN layer is Ti x2 Al y2 Ce z2 The total number of Ti, Al, and Ce atoms in N is A M2 Atomic number of N N2 Ratio A N2 / A M2 was confirmed to be in the range of 0.8 to 1.2.

[0142] The thicknesses of the TiAlCeN layer, first layer, and total coating thickness of the obtained cutting tools for each sample were measured. Specific measurement methods are as described in Embodiments 1 and 2. The results are shown in the "TiAlCeN layer," "First layer (base layer)," "First layer (surface layer)," and "Total coating thickness" columns of "Thickness (μm)" in Table 2. The description "Multilayer structure (6.0 μm) TiAlCeN layer (6 nm) / AlCrN layer (6 nm)" for Sample 6 and Samples 1-4 indicates that the coating includes a multilayer structure in which 6-nm-thick TiAlCeN layers and 6-nm-thick AlCrN layers are alternately stacked, and that the total thickness of the multilayer structure is 6.0 μm.

[0143] The crystalline structure of the TiAlCeN layer of each cutting tool sample was measured, and it was confirmed that the TiAlCeN layer of all samples had a cubic crystalline structure.

[0144] <Cutting test> A cutting test was performed using each sample cutting tool under the following conditions, and the cutting time (minutes) was measured until the crater wear width reached 0.5 mm or until chipping of the cutting edge occurred. The longer the cutting time, the longer the tool life of the cutting tool was judged to be. The results are shown in the "Cutting Test" column in Table 2.

[0145] (Cutting conditions) Work material: SCM435 round bar Cutting speed Vc:250m / min Feed rate fz: 0.2 mm / rev Depth of cut ap: 1.5 mm Wet method The above cutting conditions place a heavy load on the cutting edge, which makes it easy for thermal wear to occur on the rake face.

[0146] [Table 2]

[0147] <Consideration> The cutting tools of Samples 1 to 15 correspond to Examples. The cutting tools of Samples 1-1 to 1-7 correspond to Comparative Examples. It was confirmed that the cutting tools of Samples 1 to 15 (Examples) have longer tool life than the cutting tools of Samples 1-1 to 1-7 (Comparative Examples).

[0148] For Samples 1-2 and 1-3, a shielding material was used when forming the TiAlCeN layer, but "z1-z2" was less than 0.010 (0.008), making them comparative examples. The reason for this is presumably that the absolute amount reaching the substrate is small due to the small amount of Ce contained in the target composition, and that the distance between the shielding material and the substrate is set to 0.5 mm, so the influence of the shielding material extends to the rake face, making it difficult to see the difference in the amount of Ce between the rake face and flank face.

[0149] [Example 2] <Cutting tool manufacturing> Cutting tools were produced and their tool lives were evaluated as follows. <Process of preparing substrate> As the substrate, a cutting tip for milling made of P20 cemented carbide (model number: SEET13T3AGSN (manufactured by Sumitomo Electric Hardmetal Corp.)) described in JIS B 4053: 2013 was prepared. The substrate was placed in a substrate holder of an arc ion plating device.

[0150] <<Coating Forming Process>>

[0151] As the target material, a sintered alloy having the composition shown in the "TiAlCeN layer" and "first layer" columns of "target material composition" in Table 3 was prepared.

[0152] The target material was placed in the arc evaporation source of an arc ion plating device. Next, the chamber of the device was evacuated to a vacuum of 0.5 Pa or less, and the substrate temperature was heated to 450°C. Ar gas was then introduced into the chamber to create an Ar atmosphere of 2.5 Pa. In this state, a bias voltage of -800 V was applied to the substrate, and ion bombardment treatment with Ar gas was performed to clean the surface of the substrate.

[0153] (Sample 101, Sample 102, Samples 105 to 108, Samples 110 to 112, Sample 2-2, Sample 2-3) Next, a shielding material was placed in the chamber. The positional relationship between the target material, substrate, and shielding material was as shown in Figure 15. That is, the substrate 2 was placed so that its flank 12 faced the target material 51. The shielding material 50 was placed so that it faced the rake face 11 of the substrate 2. The distance between the shielding material 50 and the substrate 2 was 4 mm.

[0154] Next, nitrogen gas was introduced into the chamber to create a reaction atmosphere of 3.5 Pa. In this state, an arc current was discharged on the surface of the TiAlCeN layer target, a bias voltage was applied to the substrate, and a TiAlCeN layer was formed on the substrate while the substrate holder holding the substrate was rotated, resulting in a cutting tool. The TiAlCeN layer formation conditions were as follows: Base material temperature: 500℃ Bias voltage: -100V Arc current: 190A Reactant gas pressure: 3.5Pa

[0155] (Sample 2-4, Sample 2-5) Using the target for the TiAlCeN layer of each sample, a TiAlCeN layer was formed on the substrate under the same formation conditions (substrate temperature, bias voltage, arc current, reaction gas composition, reaction gas pressure) as those for sample 101, except that no shielding material was installed, to obtain a cutting tool.

[0156] (Sample 103) Using the target for the TiAlCeN layer of sample 103, a TiAlCeN layer was formed on the substrate under the same formation conditions (substrate temperature, bias voltage, arc current, reaction gas composition, reaction gas pressure, distance between the shielding material and the substrate) as those of sample 1. Next, using the target for the first layer, nitrogen gas was introduced from the gas inlet, and the first layer (TiAlSiN layer) was formed as a surface layer on the TiAlCeN layer while rotating the substrate holder, thereby obtaining a cutting tool.

[0157] (Sample 109) Nitrogen gas was introduced into the chamber to create an atmosphere of 3.5 Pa. In this state, an arc current was discharged on the surface of the target for the first layer, a bias voltage was applied to the substrate side, and the substrate holder was rotated to form the first layer (TiN layer) as a base layer on the surface of the substrate.

[0158] Next, using the target for the TiAlCeN layer of sample 109, a TiAlCeN layer was formed on the substrate under the same formation conditions as those of sample 101 (substrate temperature, bias voltage, arc current, reaction gas composition, reaction gas pressure, distance between the shielding material and the substrate), thereby obtaining a cutting tool.

[0159] (Sample 104) The target for the TiAlCeN layer of sample 104 and the target for the first layer were placed adjacent to each other in the chamber. That is, the target for the TiAlCeN layer and the target for the first layer were placed so that when the substrate holder rotated, the positional relationship between the TiAlCeN layer target and the substrate 2 was the same as the positional relationship between the first layer target and the substrate 2.

[0160] Next, a shielding material was placed in the chamber. The positional relationship between the target material, the substrate, and the shielding material was as shown in FIG.

[0161] Next, while rotating the substrate holder at 5 rpm, TiAlCeN layers and AlCrN layers were alternately laminated on the substrate under the same formation conditions as Sample 1 (substrate temperature, bias voltage, arc current, reactive gas composition, reactive gas pressure, distance between the shielding material and the substrate), forming a coating with a multilayer structure and obtaining a cutting tool.

[0162] (Sample 2-1) A multilayer coating was formed on the substrate under the same conditions (substrate temperature, bias voltage, arc current, reaction gas composition, reaction gas pressure) as those for sample 104, except that no shielding material was installed, and a cutting tool was obtained.

[0163] [Table 3] <Evaluation> <Coating composition> Regarding the TiAlCeN layers of the cutting tools of each sample obtained, the composition of the first TiAlCeN layer located on the flank was Ti x1 Al y1 Ce z1 N, and the composition of the second TiAlCeN layer located at the cutting edge x2 Al y2 Ce z2 The composition of the first TiAlCeN layer was measured. The specific measurement method is as shown in the first and second embodiments. The results are shown in Table 4 in the "x1", "y1", and "z1" columns for "first TiAlCeN layer" and the "x2", "y2", and "z2" columns for "second TiAlCeN layer". Furthermore, the value of "z1-z2" is also shown in Table 4. It was confirmed that x1+y1+z1=1 and x2+y2+z2=1 in all samples. Furthermore, the composition of the first TiAlCeN layer, Ti, was measured in all samples. x1 Al y1 Ce z1 The total number of Ti, Al, and Ce atoms in N is A M1 Atomic number of N N1 Ratio A N1 / A M1 , and the composition of the second TiAlCeN layer is Ti x2 Al y2 Ce z2 The total number of Ti, Al, and Ce atoms in N is A M2 Atomic number of N N2 Ratio A N2 / A M2 was confirmed to be in the range of 0.8 to 1.2.

[0164] The thicknesses of the TiAlCeN layer, first layer, and total coating of each cutting tool sample were measured. Specific measurement methods are as described in Examples 1 and 2. The results are shown in Table 4 under "Thickness (μm)" in the columns "TiAlCeN layer," "First layer (base layer)," "Second layer (surface layer)," and "Total coating." The description "Multilayer structure (5.0 μm) TiAlCeN layer (6 nm) / AlCrN layer (7 nm)" for Sample 104 and Sample 2-1 indicates that the coating includes a multilayer structure in which 6-nm-thick TiAlCeN layers and 7-nm-thick AlCrN layers are alternately stacked, and that the total thickness of the multilayer structure is 5.0 μm.

[0165] The crystalline structure of the TiAlCeN layer of each cutting tool sample was measured, and it was confirmed that the TiAlCeN layer of all samples had a cubic crystalline structure.

[0166] <Cutting test> A cutting test was performed using each sample cutting tool under the following conditions, and the cutting distance (m) was measured until the wear width on the flank side reached 200 μm or the thermal crack reached 200 μm. The longer the cutting distance, the longer the tool life of the cutting tool was determined to be. The results are shown in the "Cutting Test" column in Table 4.

[0167] (Cutting conditions) Work material: SCM435H block material Cutting speed Vc:350m / min Feed rate fz: 0.2 mm / rev Depth of cut ap: 2.0 mm dry method The above cutting conditions place a large load on the cutting edge, which tends to cause mechanical wear and thermal cracks on the flank.

[0168] [Table 4]

[0169] <Consideration> The cutting tools of Samples 101 to 112 correspond to Examples. The cutting tools of Samples 2-1 to 2-5 correspond to Comparative Examples. It was confirmed that the cutting tools of Samples 101 to 112 (Examples) had longer tool life than the cutting tools of Samples 2-1 to 2-5 (Comparative Examples).

[0170] Although the embodiments and examples of the present disclosure have been described above, it is originally intended that the configurations of the above-described embodiments and examples may be appropriately combined or modified in various ways. The embodiments and examples disclosed herein are illustrative in all respects and should not be considered limiting. The scope of the present invention is defined by the claims rather than the above-described embodiments and examples, and it is intended to include any modifications within the scope of the claims that are equivalent to the claims. [Explanation of symbols]

[0171] 1 cutting tools 2 Base material 2a Rake face 2b Flank 2c cutting edge 3 Coating 11. Rake face 12 Flank 13 Cutting edge 30 TiAlCeN layer 31 1st layer 32 Base layer 33 Surface layer 50 Shielding material 51 Target material 52 Chamber

Claims

1. 1. A cutting tool comprising a substrate and a coating disposed on the substrate, The cutting tool comprises: Rake face, a flank surface connected to the rake surface; and a cutting edge formed by a boundary portion between the rake face and the flank face, the coating comprises a TiAlCeN layer; The TiAlCeN layer is a first TiAlCeN layer located on the rake face or the flank face; a second TiAlCeN layer located on the cutting edge; The composition of the first TiAlCeN layer is Ti ｘ１ Al ｙ１ Ce ｚ１ N, The composition of the second TiAlCeN layer is Ti ｘ２ Al ｙ２ Ce ｚ２ N, where: x1+y1+z1=1, x2+y2+z2=1, 0.300<y1≦0.700, 0.300<y2≦0.700, 0.010<z1≦0.100, 0<z2≦0.090, and A cutting tool, wherein z1-z2≧0.

010.

2. The cutting tool according to claim 1 , wherein the TiAlCeN layer has a thickness of 0.5 μm to 15 μm.

3. the coating further comprises a first layer; The first layer is at least one element selected from the first group consisting of Group 4 elements, Group 5 elements, Group 6 elements, aluminum, and silicon of the periodic table; or 3. The cutting tool according to claim 1, comprising a first compound comprising at least one element selected from the first group and at least one element selected from a second group consisting of carbon, nitrogen, oxygen, and boron.

4. 4. The cutting tool of claim 3, wherein the first group consists of titanium, chromium, aluminum, and silicon.

5. 3. The cutting tool according to claim 1, wherein the coating has a thickness of 0.5 μm or more and 15 μm or less.

6. The cutting tool according to claim 3 , wherein the coating includes a multi-layer structure in which the TiAlCeN layers and the first layers are alternately stacked.

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