Cutting tool

Abstract

A cutting tool is a cutting tool having a base material and a coating film provided on the base material, the cutting tool including a rake face, a flank face connected to the rake face, and a cutting edge region constituted by a boundary portion of the rake face and the flank face, the coating film including a TiSiCN layer, the TiSiCN layer having a first TiSiCN layer located on the rake face, a second TiSiCN layer located on the cutting edge region, the first TiSiCN layer having a composition of Ti (1‑Xr) Si Xr CN, the second TiSiCN layer having a composition of Ti (1‑Xe) Si Xe CN, the Xr and the Xe each being 0.010 or more and 0.100 or less, and satisfying a relationship of Xr-Xe≥0.003.

Description

Technical Field

[0001] This disclosure relates to cutting tools. Background Technology

[0002] Previously, cutting tools having a substrate and a coating disposed on the substrate were used for cutting operations (Patent Document 1, Patent Document 2, and Non-Patent Document 1).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: International Publication No. 2013 / 083447

[0006] Patent Document 2: International Publication No. 2018 / 146013

[0007] Non-patent literature

[0008] Non-patent document 1: Shinya Imamura et al., "Properties and cutting performance of AlTiCrN / TiSiCN bilayer coatings deposited by cathodic-arcion plating", Surface and Coatings Technology, 202, (2007), 820-825 Summary of the Invention

[0009] The cutting tool disclosed herein is a cutting tool having a substrate and a coating disposed on the substrate, wherein,

[0010] The cutting tool contains

[0011] front face,

[0012] The flank face connected to the rake face, and

[0013] The cutting edge region formed by the boundary between the rake face and the flank face.

[0014] The coating contains a TiSiCN layer.

[0015] The TiSiCN layer has

[0016] The first TiSiCN layer located on the rake face,

[0017] The second TiSiCN layer is located in the cutting edge region.

[0018] The first TiSiCN layer is composed of Ti (1-Xr) Si XrCN

[0019] The second TiSiCN layer is composed of Ti (1-Xe) Si Xe CN

[0020] The values ​​of Xr and Xe are both greater than 0.010 and less than 0.100, and they satisfy the relationship Xr-Xe≥0.003. Attached Figure Description

[0021] Figure 1 This is a perspective view showing an example of a cutting tool according to one embodiment of the present disclosure.

[0022] Figure 2 yes Figure 1 A cross-sectional view of the cutting tool, from Figure 1 A cross-sectional view viewed in the direction of the arrow along line II-II.

[0023] Figure 3 It means Figure 1 The diagram with the diagonal lines is a sectional perspective view of region III.

[0024] Figure 4 Is Figure 2 The sectional view shown is a partial view of the honing process performed on the cutting edge.

[0025] Figure 5 Is Figure 3 The sectional perspective view shown is a sectional perspective view of the cutting edge where honing has been performed.

[0026] Figure 6 Is Figure 2 The sectional view shown is a partial view of the case where negative cutting edge machining is performed on the cutting edge.

[0027] Figure 7 Is Figure 3 The sectional perspective view shown is a case where negative cutting edge machining has been performed on the cutting edge.

[0028] Figure 8 Is Figure 2 The sectional view shown is a partial view of the cutting edge where honing and negative cutting edge machining have been performed.

[0029] Figure 9 Is Figure 3 The sectional perspective view shown is a sectional perspective view of the cutting edge where honing and negative cutting edge machining have been performed.

[0030] Figure 10 This is a cross-sectional view schematically illustrating an example of the coating on a cutting tool according to one embodiment of this disclosure.

[0031] Figure 11 It is a diagram used to illustrate the cutting position of a cutting tool.

[0032] Figure 12 These are additional diagrams used to illustrate the cutting position of a cutting tool.

[0033] Figure 13 This diagram illustrates the method for setting the measurement field of view in determining the composition of TiSiCN layers.

[0034] Figure 14 This is a schematic cross-sectional view of an example of a CVD apparatus used in the method for manufacturing cutting tools according to Embodiment 2.

[0035] Figure 15 yes Figure 14 A magnified view of region XV.

[0036] Figure 16 yes Figure 15 The end face view of the nozzle is from Figure 15 The end view viewed in the direction of the arrows along the XVI-XVI lines.

[0037] Figure 17 yes Figure 15 The end face view of the nozzle is from Figure 15 End view viewed in the direction of the arrow along line XVII-XVII.

[0038] Figure 18 yes Figure 15 The end face view of the nozzle is from Figure 15 End view viewed in the direction of the arrows along the XVIII-XVIII line.

[0039] Figure 19 This is an example of a high-angle annular dark-field scanning transmission electron microscope (HAADF-STEM) image showing a cross-section of the TiSiCN layer of the cutting tool according to Embodiment 1.

[0040] Figure 20 This is a schematic cross-sectional view illustrating another example of the coating on a cutting tool according to one embodiment of this disclosure.

[0041] Figure 21 This is a schematic cross-sectional view illustrating another example of the coating on a cutting tool according to one embodiment of this disclosure. Detailed Implementation

[0042] [The problem this disclosure aims to solve]

[0043] In recent years, the demand for improved tool life has been increasing, especially in interrupted turning processes involving steel. Among the key factors for further improving tool life in these processes are wear resistance and chip resistance. Cutting tools with a TiSiCN coating generally exhibit excellent wear resistance due to the high hardness of the TiSiCN layer. However, the TiSiCN layer contains a significant amount of amorphous material, making it susceptible to shear stress and prone to chipping, which can begin as film failure. Therefore, extending tool life is crucial, particularly in interrupted turning processes involving steel, by achieving both excellent wear resistance and excellent chip resistance.

[0044] [The Effects of This Disclosure]

[0045] According to this disclosure, cutting tools with a long tool life can be provided, particularly in intermittent turning processes involving steel.

[0046] [Description of embodiments of this disclosure]

[0047] First, embodiments of this disclosure will be listed and described.

[0048] (1) The cutting tool disclosed herein is a cutting tool having a substrate and a coating disposed on the substrate, wherein,

[0049] The cutting tool includes

[0050] front face,

[0051] The flank face connected to the rake face, and

[0052] The cutting edge region formed by the boundary portion of the rake face and the flank face.

[0053] The coating comprises a TiSiCN layer.

[0054] The TiSiCN layer has

[0055] The first TiSiCN layer located on the rake face,

[0056] The second TiSiCN layer is located in the cutting edge region.

[0057] The first TiSiCN layer is composed of Ti (1-Xr) Si Xr CN

[0058] The second TiSiCN layer is composed of Ti (1-Xe) Si Xe CN

[0059] The values ​​of Xr and Xe are both greater than 0.010 and less than 0.100, and they satisfy the relationship Xr-Xe≥0.003.

[0060] According to this disclosure, cutting tools with a long tool life can be provided, particularly in intermittent turning processes involving steel.

[0061] (2) In (1) above, preferably, the TiSiCN layer is composed of multiple hard particles.

[0062] The hard particles have a layered structure consisting of alternating layers with relatively high silicon concentration and layers with relatively low silicon concentration. This results in a longer tool life, particularly in intermittent turning processes involving steel.

[0063] (3) In (2) above, preferably, the average value of the periodic width of the layered structure is 3 nm or more and 20 nm or less. Therefore, it can also have a longer tool life, especially in intermittent turning processes involving steel.

[0064] (4) In any of (1) to (3) above, preferably, the TiSiCN layer has a columnar structure. This results in a longer tool life, particularly in intermittent turning processes involving steel.

[0065] (5) In any of (1) to (4) above, preferably, the TiSiCN layer has a cubic crystal structure of 90% or more by volume. This results in a longer tool life, particularly in intermittent turning processes involving steel.

[0066] (6) In any of (1) to (5) above, preferably, the thickness of the TiSiCN layer is 2.0 μm or more and 15 μm or less. This results in a longer tool life, particularly in intermittent turning processes involving steel.

[0067] [Details of the embodiments disclosed herein]

[0068] Hereinafter, a specific example of a cutting tool according to one embodiment of the present disclosure (hereinafter also referred to as "this embodiment") will be described with reference to the accompanying drawings. In the drawings of this disclosure, the same reference numerals denote the same or equivalent parts. In addition, the dimensional relationships of length, width, thickness, depth, etc. are appropriately changed for the sake of clarity and simplification of the drawings, and do not necessarily represent actual dimensional relationships.

[0069] In this specification, the expression "A~B" refers to the upper and lower limits of the range (i.e., above A and below B). When no unit is recorded in A, but only in B, the unit of A is the same as the unit of B.

[0070] In this specification, when compounds are represented by chemical formulas, the atomic ratio is assumed to include all conventionally known atomic ratios unless otherwise specified, and is not necessarily limited to atomic ratios within the stoichiometric range. For example, when referred to as "TiN", the ratio of the number of atoms constituting TiN includes all conventionally known atomic ratios.

[0071] [Implementation Method 1: Cutting Tool]

[0072] use Figures 1 to 13 , Figure 19 A cutting tool according to one embodiment of this disclosure will be described.

[0073] One embodiment of this disclosure (hereinafter also referred to as "this embodiment") is a cutting tool 1 comprising a substrate 2 and a coating 3 disposed on the substrate 2, wherein...

[0074] The cutting tool 1 includes:

[0075] Front face 11

[0076] The flank face 12 connected to the rake face 11, and

[0077] The cutting edge 13 region is formed by the boundary portion of the rake face 11 and the flank face 12.

[0078] The coating 3 contains a TiSiCN layer 30.

[0079] The TiSiCN layer 30 has:

[0080] The first TiSiCN layer located on the rake face 11,

[0081] The second TiSiCN layer is located in region 13 of the cutting edge.

[0082] The first TiSiCN layer is composed of Ti (1-Xr) Si Xr CN

[0083] The second TiSiCN layer is composed of Ti (1-Xe) Si Xe CN

[0084] The values ​​of Xr and Xe are both greater than 0.010 and less than 0.100, and they satisfy the relationship Xr-Xe≥0.003.

[0085] According to this disclosure, a cutting tool 1 with a long tool life can be provided, particularly in intermittent turning processes involving steel. The reason for this is speculated as follows.

[0086] The aforementioned Xr and Xe are both 0.010 to 0.100, and satisfy the relationship Xr - Xe ≥ 0.003. Within the range where Xr and Xe are 0.10 or less, the higher the values ​​of Xr and Xe (in other words, the higher the Si concentration), the higher the hardness at the nanoindentation, and the better the "wear resistance." On the other hand, there is a tendency for the "damage resistance" to decrease due to reduced toughness. Especially in discontinuous turning processes involving steel, cracking due to mechanical impact is prone to occur in the cutting edge 13 region, thus requiring higher toughness ("damage resistance") in the cutting edge 13 region. In the cutting tool 1 of this disclosure, since the aforementioned Xr and Xe are both 0.010 to 0.100, the TiSiCN layer 30 as a whole can possess moderate hardness, thus exhibiting excellent "wear resistance." Furthermore, in the cutting tool 1 of this disclosure, since the above-mentioned Xr and Xe satisfy the relationship Xr-Xe≥0.003, the concentration of Si in the cutting edge 13 region is suppressed to a relatively low level, so in particular, it is possible to have high toughness ("damage resistance") in the cutting edge 13 region.

[0087] That is, according to this disclosure, since the cutting tool can have both excellent "wear resistance" and excellent "damage resistance", it can provide a cutting tool with a long tool life, especially in intermittent turning processes involving steel.

[0088] Structure of Cutting Tools

[0089] like Figure 1 As shown, the cutting tool 1 of this embodiment has a surface including an upper surface, a lower surface, and four side surfaces, and is generally a slightly thinner quadrangular prism in the vertical direction. In addition, a through hole is formed in the cutting tool 1 that penetrates the upper and lower surfaces, and in the boundary portions of the four side surfaces of the cutting tool 1, adjacent side surfaces are connected to each other by arc surfaces.

[0090] In the cutting tool 1 of this embodiment, the upper and lower surfaces constitute the rake face 11, and the four side surfaces (and the arcuate surfaces connecting them) constitute the flank face 12. Furthermore, the boundary between the rake face 11 and the flank face 12 functions as the cutting edge 13 region. In other words, the surface of the cutting tool 1 of this embodiment (upper surface, lower surface, four side surfaces, the arcuate surfaces connecting these side surfaces, and the inner circumferential surface of the through hole) includes the rake face 11, the flank face 12 connected to the rake face 11, and the cutting edge 13 region formed by the boundary between the rake face 11 and the flank face 12.

[0091] The boundary portion of the rake face 11 and the flank face 12, i.e., the cutting edge 13 region, refers to "the portion where the edge line E constituting the boundary between the rake face 11 and the flank face 12 is joined together with the portion of the rake face 11 and the flank face 12 that is near the edge line E". "The portion of the rake face 11 and the flank face 12 that is near the edge line E" is determined by the shape of the cutting edge 13 of the cutting tool 1. The following description covers the cases where the cutting tool 1 is a tool with a sharp edge shape, a tool with a honed shape that has undergone honing, and a tool with a negative cutting edge shape that has undergone negative cutting edge machining.

[0092] Figure 2 as well as Figure 3 A cutting tool 1 with a sharp edge shape. In a cutting tool 1 with a sharp edge shape as described above, "the portion of the rake face 11 and the flank face 12 near the edge line E" is defined as the area where the distance (straight-line distance) D from the edge line E is 50 μm or less (in... Figure 3 (The area in the middle is shaded). Therefore, the cutting edge 13 area in the sharp-edged cutting tool 1 becomes the same as in the... Figure 3 The area corresponding to the region where a dotted shadow has been applied.

[0093] Figure 4 as well as Figure 5 This refers to a cutting tool 1 with a honed shape that has undergone honing. Figure 4 as well as Figure 5 In the diagram, excluding the various parts of the cutting tool 1, an imaginary plane R including the rake face 11, an imaginary plane F including the flank face 12, an imaginary edge line EE formed by the intersection of the imaginary planes R and F, an imaginary boundary line ER that forms the boundary of the deviation between the rake face 11 and the imaginary plane R, and an imaginary boundary line EF that forms the boundary of the deviation between the flank face 12 and the imaginary plane F are shown. Furthermore, in the honed cutting tool 1, the aforementioned "edge line E" is replaced with "imaginary edge line EE".

[0094] In the honing-shaped cutting tool 1 described above, "the portion of the rake face 11 and the flank face 12 near the imaginary edge EE" is defined as the area bounded by the imaginary boundary lines ER and EF (in... Figure 5 (The area marked with a dotted shade). Therefore, the cutting edge 13 area in the honed cutting tool 1 becomes the same as the area in the... Figure 5 The area corresponding to the region where a dotted shadow has been applied.

[0095] Figure 6 as well as Figure 7 This refers to a cutting tool 1 with a negative cutting edge shape that has undergone negative cutting edge machining. Figure 6 as well as Figure 7In the diagram, excluding the various parts of the cutting tool 1, an imaginary plane R including the rake face 11, an imaginary plane F including the flank face 12, an imaginary edge line EE formed by the intersection of the imaginary planes R and F, an imaginary boundary line ER that forms the boundary of the deviation between the rake face 11 and the imaginary plane R, and an imaginary boundary line EF that forms the boundary of the deviation between the flank face 12 and the imaginary plane F are shown. Furthermore, in the cutting tool 1 with a negative cutting edge shape, the aforementioned "edge line E" is replaced with "imaginary edge line EE".

[0096] In the aforementioned negative-edge cutting tool 1, "the portion of the rake face 11 and the flank face 12 near the imaginary edge line EE" is defined as the area bounded by the imaginary boundary lines ER and EF (in... Figure 7 (The area with dotted shading applied). Therefore, the cutting edge 13 area in the negative-edge cutting tool 1 becomes the same as in... Figure 7 The area corresponding to the region where a dotted shadow has been applied.

[0097] Figure 8 as well as Figure 9 This describes a cutting tool 1 with a shape that has undergone a combination of honing and negative cutting edge processing. Figure 8 as well as Figure 9 In the diagram, excluding the various parts of the cutting tool 1, an imaginary plane R including the rake face 11, an imaginary plane F including the flank face 12, an imaginary edge line EE formed by the intersection of the imaginary planes R and F, an imaginary boundary line ER that forms the boundary of the deviation between the rake face 11 and the imaginary plane R, and an imaginary boundary line EF that forms the boundary of the deviation between the flank face 12 and the imaginary plane F are shown. Furthermore, in a cutting tool 1 with a shape that incorporates honing and negative cutting edge processing, the aforementioned "edge line E" is replaced with "imaginary edge line EE". Additionally, the imaginary plane R is defined as a plane including the area of ​​the rake face 11 near the cutting edge 13.

[0098] In a cutting tool 1 with the shape described above, "the portion of the rake face 11 and the flank face 12 that is near the imaginary edge line EE" is defined as the area enclosed by the imaginary boundary line ER and the imaginary boundary line EF. Figure 9 (The area with dotted shading applied). Therefore, the cutting edge 13 area in the cutting tool 1 becomes the same as the area in... Figure 9 The area corresponding to the region where a dotted shadow has been applied.

[0099] Figure 1 The cutting tool 1 is indicated as an indexable cutting insert for turning, but the cutting tool 1 is not limited to this, and can include drills, end mills, indexable cutting inserts for drills, indexable cutting inserts for end mills, indexable cutting inserts for milling, metalworking saws, tooth cutting tools, reamers, taps, etc.

[0100] Furthermore, when the cutting tool 1 is an indexable cutting insert or the like, the cutting tool 1 includes both indexable cutting inserts with and without chip breakers. Additionally, the cutting edge 13 region may include an edge with a sharp edge (the intersection of the rake face 11 and the flank face 12) (see reference). Figures 1 to 3 Honing (the area where sharp edges are rounded) (see reference) Figure 4 as well as Figure 5 The machined area, the negative cutting edge zone (the area that has been chamfered) (refer to) Figure 6 as well as Figure 7 The processed areas and the areas after honing and negative edge band machining (refer to...) Figure 8 as well as Figure 9 Any one of them.

[0101] like Figure 2 As shown, 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 on the entire surface. Specifically, the coating 3 is disposed on the surface of the substrate 2 in a region where the distance (straight-line distance) D from the edge line E or the imaginary edge line EE is 300 μm or less. As long as the effects of this disclosure are achieved, even if the composition of the coating 3 is locally different, it will not depart from the scope of this embodiment.

[0102] As the substrate 2, any substrate conventionally known as such can be used. For example, cemented carbide (WC-based cemented carbide, cemented carbide containing WC and Co, cemented carbide further containing carbonitrides such as Ti, Ta, and Nb, etc.), cermet (cermet with TiC, TiN, TiCN, etc. as the main components), high-speed steel, ceramics (titanium carbide, silicon carbide, silicon nitride, aluminum nitride, alumina, etc.), cubic boron nitride sintered bodies, or diamond sintered bodies are preferred. Among the various substrates 2 mentioned above, WC-based cemented carbide and cermet (especially TiCN-based cermet) are particularly preferred. This is because these substrates 2 exhibit a particularly excellent balance between hardness and strength at high temperatures, providing superior properties as the substrate 2 of the cutting tool 1.

[0103] <Lamination>

[0104] The coating 3 in Embodiment 1 includes a TiSiCN layer 30. The coating 3 in this embodiment may include other layers 31, or it may not include other layers 31, as long as it includes the TiSiCN layer 30. Examples of other layers 31 include a substrate layer, an intermediate layer, and a surface layer. The substrate layer can be disposed between the substrate and the TiSiCN layer. Figure 20Examples of substrate layers include TiN, TiC, TiCN, TiBN, or Al2O3 layers. An intermediate layer can be disposed between the substrate layer and the TiSiCN layer (not shown), or between the TiSiCN layer and the surface layer. Figure 21 As an intermediate layer, examples include TiCN layers or TiCNO layers. A surface layer can be disposed on the outermost surface of the coating. Figure 21 As a surface layer, examples include TiC layers, TiCN layers, TiN layers, or Al2O3 layers.

[0105] The thickness of the coating 3 is preferably 2.0 μm to 20.0 μm. If the thickness of the coating 3 is less than 2.0 μm, there is a tendency for insufficient tool life. If the thickness of the coating 3 exceeds 20.0 μm, stress will be generated within the coating during processing, making it prone to peeling or damage. The thickness of the coating 3 is more preferably 3.0 μm to 19.0 μm, and even more preferably 4.0 μm to 18.0 μm. The method for measuring the thickness of the coating will be described later.

[0106] <TiSiCN layer>

[0107] The TiSiCN layer 30 in this embodiment has a first TiSiCN layer located on the rake face 11 and a second TiSiCN layer located in the cutting edge region 13. That is, within one TiSiCN layer 30, there is a region composed of the first TiSiCN layer and a region composed of the second TiSiCN layer.

[0108] (Composition of the TiSiCN layer)

[0109] The composition of the first TiSiCN layer is Ti (1-Xr) Si Xr CN, the composition of the second TiSiCN layer is Ti (1-Xe) Si Xe CN. Here, Xr and Xe are both 0.010 to 0.100, and satisfy the relationship Xr - Xe ≥ 0.003. Thus, the cutting tool can possess both excellent "wear resistance" and excellent "damage resistance".

[0110] From the viewpoint of improving the wear resistance of the rake face 11, the lower limit of Xr is preferably 0.013 or more, more preferably 0.017 or more, and even more preferably 0.020 or more. From the viewpoint of suppressing the decrease in toughness (resistance to chipping) of the rake face 11 that accompanies the improvement in wear resistance, the upper limit of Xr is preferably 0.100 or less, more preferably 0.090 or less, and even more preferably 0.080 or less. Xr is preferably 0.013 or more and 0.100 or less, preferably 0.017 or more and 0.090 or less, and even more preferably 0.020 or more and 0.080 or less.

[0111] From the viewpoint of improving the wear resistance of the cutting edge 13 region, the lower limit of Xe is preferably 0.010 or more, more preferably 0.015 or more, and even more preferably 0.020 or more. From the viewpoint of suppressing the decrease in toughness (resistance to chipping) of the cutting edge 13 region along with the improvement of wear resistance, the upper limit of Xe is preferably 0.097 or less, more preferably 0.090 or less, and even more preferably 0.080 or less. Xe is preferably 0.010 or more and 0.097 or less, preferably 0.015 or more and 0.090 or less, and even more preferably 0.020 or more and 0.080 or less.

[0112] From the viewpoint of particularly improving the wear resistance of the rake face 11 and especially the chip resistance of the cutting edge region 13, the lower limit of "Xr-Xe" is preferably 0.003 or more, more preferably 0.008 or more, and even more preferably 0.015 or more. From the viewpoint of suppressing the reduction in toughness caused by stress concentration in the film due to excessive concentration gradient, the upper limit of "Xr-Xe" is preferably 0.100 or less, more preferably 0.090 or less, and even more preferably 0.080 or less. "Xr-Xe" is preferably 0.003 or more and 0.100 or less, preferably 0.008 or more and 0.090 or less, and even more preferably 0.015 or more and 0.080 or less.

[0113] The aforementioned Xr and Xe can be determined by point analysis using a scanning electron microscope (SEM-EDS) equipped with an energy-dispersive X-ray spectrometer. The specific method is explained below.

[0114] (A1) A test sample is obtained by cutting the cutting tool 1 in a manner that exposes a cross-section along the thickness direction of the coating 3. The cutting position is preferably determined based on the actual usage of the cutting tool.

[0115] Figure 11 as well as Figure 12This diagram illustrates the cutting position of the cutting tool 1. When you want to use the cutting tool 1 to cut the workpiece through the cutting edge 13 at the corner (the part depicting the apex of the arc), as shown... Figure 11 As shown, the cutting is performed in such a way that the cross-section containing the line L1 that bisects the corner is exposed along the thickness direction of the coating 3. On the other hand, when it is desired to use the cutting tool 1 to cut the workpiece through the cutting edge 13 of the straight portion (the portion depicting the straight line), as... Figure 12 As shown, the cutting is performed in such a way that a line L2, which includes the cutting edge 13 perpendicular to the straight portion, is exposed along the thickness direction of the coating 3. The exposed cut surface is then ground to make it smooth, as needed.

[0116] (B1) The cut surface described above was observed using SEM-EDS at 5000x magnification. A rectangular measurement field of view was set, comprising three locations with a thickness of 1 μm or more in the coating 3 and a thickness of 5 μm or more in the direction perpendicular to the thickness direction, including the first TiSiCN layer located on the rake face 11 or the second TiSiCN layer located in the cutting edge region 13. The thickness direction of the measurement field of view was set to include the thickness of all the first TiSiCN layers or the thickness of the second TiSiCN layer.

[0117] Furthermore, when the measurement field of view is set in a manner that includes a first TiSiCN layer located on the rake face 11, the measurement field of view is set in a manner that includes a first TiSiCN layer on the rake face 11 side at a distance of 200 μm to 500 μm from the edge E or the imaginary edge EE. When the measurement field of view is set in a manner that includes a second TiSiCN layer located in the cutting edge 13 region, the measurement field of view is set in a manner that includes a second TiSiCN layer on the cutting edge 13 region side at a distance of 200 μm to 500 μm from the edge E or the imaginary edge EE.

[0118] like Figure 13 As shown, the three measurement fields mentioned above are set to the thickness direction of each measurement field (in...). Figure 13 In the middle (in the direction indicated by arrow T), the edges on each other are in contact, and the measurement fields are continuous with each other. A portion of each measurement field may also overlap (in...). Figure 13 In the diagram, overlapping areas are indicated by diagonal lines. This is set in a direction perpendicular to the thickness direction of each measurement field of view (in...). Figure 13 In the middle (in the direction indicated by arrow H), the length of the overlapping part of the edge is less than 2μm.

[0119] (C1) First, in each of the three measurement fields described above, a region of the first TiSiCN layer is determined. Specifically, elemental mapping based on SEM-EDS is performed for each measurement field to determine the layer containing Ti and Si. This determined layer corresponds to the first TiSiCN layer. Next, the three measurement fields are observed at 5000x magnification, and the Ti to Si composition ratio in the first TiSiCN layer is analyzed. The ratio Xr of Si relative to the total number of Ti and Si atoms is calculated. The average value of Xr from the three measurement fields corresponds to the Ti composition of the first TiSiCN layer in this embodiment. (1-Xr) Si Xr Xr in CN.

[0120] For the composition of the second TiSiCN layer located in the cutting edge region, Ti (1-Xe) Si Xe Xe in CN is measured using the same method as Xr described above, except that the measurement field of view is set within the second TiSiCN layer located in the region of the cutting edge 13. This measurement field of view is set within the second TiSiCN layer at a distance of less than 20 μm from the edge E or the imaginary edge EE.

[0121] The SEM-EDS analysis described above can be performed, for example, using a scanning electron microscope (S-3400N type, manufactured by Hitachi High Technology Corporation) under the following conditions.

[0122] Accelerating voltage: 15kV

[0123] Process time: 5

[0124] Spectral range: 0~20keV

[0125] Number of channels: 1K

[0126] Frame rate: 150

[0127] X-ray extraction angle: 30°

[0128] It has been confirmed that as long as the same cutting tool is used for measurement, the measurement results will not deviate even if the measurement position is arbitrarily selected.

[0129] In the above Ti (1-Xr) Si XrIn the CN layer, the ratio A:B, which is the total number of Ti and Si atoms (A) and the total number of C and N atoms (B), is not limited to 1:1. It can be any ratio other than 1:1 as long as it does not impair the effect of this disclosure. For example, A:B = 1:0.8 to 1.1. Furthermore, except for the differences described in (C1) above, B is obtained using the same method as Xr: "Analyzing the composition ratio of Ti to Si to C to N in the first TiSiCN layer, the ratio of the total number of C and N atoms to the total number of Ti, Si, C, and N atoms is calculated. Furthermore, the number of C atoms and the number of N atoms are determined using TEM-EDS. The average of this ratio from three measurement fields corresponds to the composition Ti of the first TiSiCN layer in this embodiment." (1-Xr) Si Xr The above B in CN.

[0130] In Ti (1-Xe) Si Xe In the CN layer, the ratio A:B, which is the total number of Ti and Si atoms (A), to the total number of C and N atoms (B), is not limited to 1:1. It can be any ratio other than 1:1, provided it does not impair the effectiveness of this disclosure. For example, A:B can be 1:0.8 to 1.1. Furthermore, except for the analysis of the "second TiSiCN layer," this B is determined using the same method as the method used to determine B in the first TiSiCN layer.

[0131] (Thickness of the TiSiCN layer)

[0132] In this embodiment, the thickness of the TiSiCN layer 30 is preferably 2.0 μm to 15 μm. If the thickness of the TiSiCN layer 30 is less than 2.0 μm, it is difficult to obtain the improved wear resistance and chipping resistance based on the TiSiCN layer 30, and there is a tendency for the tool life to become insufficient. If the thickness of the TiSiCN layer 30 exceeds 15 μm, stress will be generated in the TiSiCN layer 30 during processing, which can easily lead to peeling or damage. The thickness of the TiSiCN layer 30 is more preferably 3.0 μm to 14 μm, and even more preferably 4.0 μm to 13 μm. The method for measuring the thickness of the TiSiCN layer 30 is as follows.

[0133] (A2) The test sample is obtained by cutting the cutting tool 1 in such a way that the cross section along the thickness direction of the coating 3 is exposed, using the same method as described in (A1) of the method for determining the composition of the TiSiCN layer 30 above.

[0134] (B2) Using a scanning electron microscope (S-3400N type, manufactured by Hitachi High Technology Co., Ltd.), the cross-section described above was observed at 5000x magnification, and the thickness of the TiSiCN layer 30 was measured at six arbitrary locations along the normal direction of the surface of the substrate 2. Furthermore, of these six locations, three were located in the first TiSiCN layer, and the remaining three were located in the second TiSiCN layer. These arithmetic mean values ​​correspond to the "thickness of the TiSiCN layer 30". The measurement conditions for the above SEM were the same as those described in (C1) of the method for measuring the composition of the first TiSiCN layer.

[0135] It has been confirmed that as long as the same cutting tool 1 is used for measurement, the measurement results will not deviate even if the measurement position is arbitrarily selected.

[0136] In this embodiment, the thickness of the coating 3 and the thicknesses of the other layers 31 are also measured using the same steps as described above. It has been confirmed that, as long as the same cutting tool 1 is used for measurement, the measurement results are consistent even if the measurement location is arbitrarily selected.

[0137] (Structure of TiSiCN layer)

[0138] The aforementioned TiSiCN layer 30 is composed of multiple hard particles, which preferably have a layered structure consisting of alternating layers with relatively high silicon concentration and layers with relatively low silicon concentration. Therefore, even if deformation occurs within the hard particles, resulting in cracks on the surface of the coating 3 due to cutting, the propagation of these cracks towards the substrate 2 is effectively suppressed. Furthermore, the increased hardness of both the hard particles and the TiSiCN layer 30 improves the wear resistance of the cutting tool 1. Consequently, the cutting tool 1 exhibits a longer tool life, particularly in intermittent turning operations involving steel. In the cutting tool 1, the statement that "the TiSiCN layer 30 is composed of multiple hard particles, which have a layered structure consisting of alternating layers with relatively high and low silicon concentrations" is confirmed by the methods described in (A3) to (F3) below.

[0139] (A3) Using a diamond wire cutter, cut tool 1 along the normal to the surface of the coating 3 to expose the cross-section of the TiSiCN layer 30. Perform focused ion beam processing (hereinafter also referred to as "FIB processing") on the exposed cross-section to make the cross-section a mirror finish.

[0140] (B3) The cross-section after FIB processing was observed using a high-angle annular dark-field scanning transmission electron microscope (HAADF-STEM) to identify a hard particle. The magnification was set to 2,000,000. Next, a HAADF-STEM image of the identified hard particle was obtained. Figure 19This is an example diagram showing a HAADF-STEM image of a hard particle in the cutting tool 1 of this embodiment. Figure 19 In the diagram, the black layer represents the region with a relatively low silicon concentration (low silicon concentration layer), while the white or gray layer represents the region with a relatively high silicon concentration (high silicon concentration layer).

[0141] (C3) In the above HAADF-STEM image, the measurement area (size: 50nm×50nm) is set up in such a way that it includes a low-concentration silicon layer (represented by black) and a high-concentration silicon layer (represented by white or gray) stacked seven or more layers respectively.

[0142] (D3) Within the measurement area of ​​the HAADF-STEM image described above, the stacking orientation of the high-concentration silicon layer and the low-concentration silicon layer is determined. Specifically, the electron line diffraction pattern of the restricted field of view is overlapped with the stacking orientation of the high-concentration silicon layer and the low-concentration silicon layer, and the stacking orientation is determined by the orientation shown by the diffraction spots.

[0143] (E3) In the measurement area of ​​the HAADF-STEM image above, the composition was determined by line analysis along the stacking direction using an EDX with an attached STEM. The beam diameter for line analysis was set to less than 0.5 nm, the scan interval was set to 0.5 nm, and the length of line analysis was set to 50 nm.

[0144] (F3) It has been confirmed that, under the following conditions (a1) to (b1), the hard particles have a layered structure consisting of alternating layers with relatively high silicon concentration and layers with relatively low silicon concentration.

[0145] (a1) The measurement area includes titanium (Ti), silicon (Si), carbon (C) and nitrogen (N).

[0146] (b1) The results of the line analysis were plotted as a graph in a coordinate system, where the X-axis represents the distance from the starting point of the measurement, and the Y-axis represents the number of silicon atoms X. Si Relative to the number of atoms X of silicon Si And the number of titanium atoms X Ti The total percentage {X} Si / (X Si +X Ti )}×100. In this chart, calculate the percentage {X} in the measured area. Si / (X Si +X Ti The average value of )}×100 (hereinafter also referred to as "average value"). As the distance from the starting point of the measurement increases, the percentage {X} compared to this average value... Si / (X Si +X TiLarger and smaller regions alternate. Compared to this average, the percentage {X} × 100 Si / (X Si +X Ti The larger region ()×100 corresponds to a layer with a relatively high silicon concentration. Compared to this average, the percentage {X} Si / (X Si +X Ti The smaller region ()}×100 corresponds to a layer with a relatively low silicon concentration.

[0147] It has been confirmed that as long as the test is performed in the same sample, even if the hard particles determined by (B3) are changed multiple times, the test results will have almost no deviation, and the test location will not change arbitrarily even if it is set arbitrarily.

[0148] (Average value of the periodic width of the layered structure)

[0149] The average value of the period width of the aforementioned layered structure is preferably 3 nm to 20 nm. This allows for the maintenance of deformation between the high-concentration silicon layer and the low-concentration silicon layer, improving resistance to defects, and thus extending the tool life of the cutting tool 1, especially in intermittent turning processes involving steel. Here, the period width of the layered structure refers to the distance from one high-concentration silicon layer to another high-concentration silicon layer adjacent to the low-concentration silicon layer. Furthermore, this distance is the distance between the midpoints in the thickness direction of each layer connecting the high-concentration silicon layer and the other high-concentration silicon layer. The average value of the period width of the layered structure refers to the average value of the period widths of all layered structures measured within the measurement area set as described above (C3).

[0150] In this specification, the method for determining the period width of silicon concentration is as follows. The measurement area is set using the same method as described in (A3) to (C3) above. A Fourier transform is performed on the measurement area to obtain a Fourier transform image (not shown). In this Fourier transform image, the periodicity within the measurement area is represented as a spot. The period width is calculated by taking the reciprocal of the distance between the spot and the center of the image representing the maximum intensity in the Fourier transform image.

[0151] It has been confirmed that as long as the measurement is performed on the same sample, even if the measurement position is changed and the measurement is performed multiple times, the measurement results will have almost no deviation, and the measurement position will not change arbitrarily even if it is set arbitrarily.

[0152] There is no particular limitation on the number of silicon high-concentration layers and silicon low-concentration layers constituting the layered structure (total number of layers), but for example, it is preferably 10 to 1000 layers. If the number of layers is 10 or more, grain coarsening in each silicon high-concentration layer and each silicon low-concentration layer is suppressed, and the hardness of the hard particles can be maintained. On the other hand, if the number of layers is 1000 or less, the thickness of each silicon high-concentration layer and each silicon low-concentration layer can be sufficiently ensured, and mixing between unit layers can be suppressed.

[0153] The aforementioned TiSiCN layer 30 is preferably columnar. Furthermore, here, "TiSiCN layer 30 is columnar" means "the average aspect ratio of the hard particles is 3 or more." As a result, since the stress in the shear direction of the TiSiCN layer 30 can exert higher strength, microcracks are suppressed, and wear resistance is improved. Therefore, in particular, a longer tool life can be achieved in intermittent turning processes involving steel. Furthermore, the average aspect ratio of the hard particles is determined by the following steps (A4) to (D4).

[0154] (A4) Cutting tool 1 is used to cut along the normal of the surface of the coating 3 using a diamond wire cutter to expose the cross-section of the TiSiCN layer 30. The exposed cross-section is then subjected to focused ion beam processing (hereinafter also referred to as "FIB processing") to achieve a mirror finish.

[0155] (B4) In the cross-section after FIB processing, a rectangular field of view is set. One set of sides of this field of view is set to have a length of 30 μm in the direction parallel to the surface of substrate 2, and the other set of sides is set to include the length (thickness of TiSiCN layer 30) of all TiSiCN layer 30 in the normal direction of the surface of substrate 2.

[0156] (C4) Using a high-resolution electron beam backscattering diffraction apparatus, the observation field plane is analyzed at 0.02 μm intervals to determine the measurement points within the observation field plane that have a cubic crystal structure (hereinafter also referred to as "cubic crystal structure"). Among these measurement points, if there is an azimuth difference of 5 degrees or more between measurement point A (having a cubic crystal structure) and measurement point B (adjacent to measurement point A), the area between measurement point A and measurement point B is defined as a grain boundary. Furthermore, if there is no cubic crystal measurement point adjacent to measurement point A, the outer periphery of measurement point A is defined as a grain boundary.

[0157] A grain is defined as a portion of a region surrounded by grain boundaries that contains a measurement point with cubic crystals. However, if a determined measurement point has an azimuth difference of 5 degrees or more from adjacent measurement points, or if the measurement point exists alone without a cubic crystal structure, it is not considered a grain. In other words, the portion formed by connecting two or more measurement points is treated as a grain. This process of grain boundary determination identifies the grain.

[0158] (D4) Next, image processing is performed. For each grain (each hard particle), the maximum length H of the normal direction to the surface of substrate 2, the maximum length W of the direction parallel to the surface of substrate 2, and the area S are determined. The aspect ratio A of the grain (hard particle) is calculated as A = H / W. Twenty grains (hard particles) P1 to P20 are randomly selected within the field of view. The aspect ratio is calculated for each of these twenty grains (hard particles). Based on the formula "A..." ave = (A1S1+A2S2+…+A20S20) / (S1+S2+…+Sn)” calculates the area-weighted average A of the aspect ratios A of the twenty grains (hard particles) P1 to P20. ave In the above formula, A1 to A20 are the aspect ratios A of grains (hard particles) P1 to P20, respectively. In the above formula, S1 to S20 are the areas S of grains (hard particles) P1 to P20, respectively.

[0159] In this specification, the area-weighted average value A is obtained. ave This is equivalent to the average aspect ratio of hard particles. It has been confirmed that as long as the measurement is performed on the same sample, even if the observation field is changed and the measurement is performed multiple times, the measurement results will have almost no deviation, and the results will not change arbitrarily even if the observation field is set arbitrarily.

[0160] (Crystal structure of TiSiCN layer)

[0161] The TiSiCN layer 30 preferably has a cubic crystal structure with a volume percentage of 90% or more. Therefore, since the TiSiCN layer 30 can have higher hardness, the cutting tool 1 can have better wear resistance. The TiSiCN layer 30 is more preferably a cubic crystal structure with a volume percentage of 92% or more, and even more preferably a cubic crystal structure with a volume percentage of 94% or more. The TiSiCN layer 30 is most preferably a cubic crystal structure with a volume percentage of 100%, but from a manufacturing perspective, it can have a volume percentage of 98% or less, 96% or less, or 95% or less. The TiSiCN layer 30 is preferably a cubic crystal structure with a volume percentage of 90% or more and 100% or less, more preferably 92% or more and 98% or less, and even more preferably 94% or more and 96% or less. The percentage of the cubic crystal structure in the TiSiCN layer 30 is determined by observing the microstructure using an electron beam backscattering diffraction apparatus. Specifically, firstly, the measurement points are determined by performing steps (A4) to (C4) as described above. Furthermore, in the orientation mapping image (color map), the crystalline portion of the cubic crystal form is shown "excluding black," while the portion other than the crystalline portion of the cubic crystal form is shown "black." By calculating the area ratio of the portion "excluding black" in this orientation mapping image, the percentage of the cubic crystal structure occupying the TiSiCN layer 30 is determined.

[0162] [Implementation Method 2: Method for Manufacturing a Cutting Tool]

[0163] use Figures 14-18 The manufacturing method of the cutting tool according to this embodiment will be described. The manufacturing method of the cutting tool according to this embodiment is the manufacturing method of the cutting tool described in Embodiment 1, wherein...

[0164] The method for manufacturing the cutting tool includes a first step of preparing a substrate, and...

[0165] The second step of forming a coating on the substrate,

[0166] The second step includes a second step (2a) in which the TiSiCN layer is formed by CVD using a CVD apparatus.

[0167] Process 1

[0168] In the first step, a substrate is prepared. For example, when using cemented carbide as the substrate, a commercially available substrate can be used, or it can be manufactured using a conventional powder metallurgy method. When manufacturing using a conventional powder metallurgy method, for example, WC powder and Co powder are mixed using a ball mill or the like to obtain a mixed powder. After drying the mixed powder, it is shaped into a predetermined shape to obtain a molded body. Further, by sintering the molded body, a WC-Co based cemented carbide (sintered body) is obtained. Then, a predetermined tool tip machining process, such as honing, is applied to the sintered body, enabling the manufacture of a substrate made of WC-Co based cemented carbide. Even substrates other than those described above can be prepared, as long as they are conventionally known substrates.

[0169] Process 2

[0170] Next, in the second step, a coating is formed on the aforementioned substrate. The coating is formed, for example, using... Figure 14 The CVD apparatus shown is used for this process. Within the CVD apparatus 50, multiple substrate clamps 52 holding substrates 10 are installed, and these are covered by a reaction vessel 53 made of heat-resistant alloy steel. Furthermore, a temperature control device 54 is arranged around the reaction vessel 53, which allows for the control of the temperature within the reaction vessel 53.

[0171] The CVD apparatus 50 is equipped with a nozzle 56 having two inlet ports 55 and 57. Additionally, the nozzle 56 may have another inlet port (not shown). The nozzle 56 is configured to pass through the area where the substrate assembly fixture 52 is disposed. A plurality of injection holes (a first injection hole 61, a second injection hole 62, and a third injection hole (not shown)) are formed in the portion of the nozzle 56 near the substrate assembly fixture 52.

[0172] exist Figure 14 In this process, the gases introduced into the nozzle 56 from inlets 55, 57, and another inlet (not shown) do not mix even within the nozzle 56, but are introduced into the reaction vessel 53 separately through different injection holes. The nozzle 56 is rotatable about this axis. Additionally, the CVD apparatus 50 is equipped with an exhaust pipe 59, from which exhaust gases can be discharged to the outside through the exhaust port 60. Furthermore, the fixtures and other components within the reaction vessel 53 are typically made of graphite.

[0173] <Process 2a>

[0174] In the aforementioned 2a step, the TiSiCN layer is formed using a CVD method with a CVD apparatus. This 2a step includes a 2a-1 step of ejecting TiCl4 gas, SiCl4 gas, and CH3CN gas toward the surface of the substrate. The TiCl4 gas is ejected from a plurality of second ejection holes provided in the nozzle of the CVD apparatus, and the SiCl4 gas is ejected from a plurality of first ejection holes provided in the nozzle. The CH3CN gas is ejected from a plurality of third ejection holes 63 provided in the nozzle, where the nozzle 56 also has another inlet (not shown). Figure 18 The CH3CN gas is ejected from the plurality of first injection holes and the plurality of second injection holes, provided that the nozzle 56 does not further have another inlet (not shown). Additionally, in this 2a-1 step, the nozzle rotates.

[0175] In this process, the substrate temperature inside the reaction vessel is preferably in the range of 800–900°C, and the pressure inside the reaction vessel is preferably 10–300 mbar. Furthermore, H2 gas, N2 gas, Ar gas, etc., can be used as the charge carrier gas. The charge carrier gas is ejected from the first injection hole, the second injection hole, and the third injection hole, respectively.

[0176] (Conditions used to adjust Xr and Xe)

[0177] Regarding the "conditions used to adjust Xr and Xe", the following uses... Figures 15-17 Please provide an explanation. Figure 15 The above Figure 14 A magnified view of region XV. Figure 16 yes Figure 15 The end face view of the nozzle is from Figure 15 The end view viewed in the direction of the arrows along the XVI-XVI lines. Figure 17 yes Figure 15 The end face view of the nozzle is from Figure 15 The end view viewed in the direction of the arrow along line XVII-XVII. In this process, the first jet hole 61 is set such that the distance from the height position HP of the rake face of the substrate 2 closest to it in the CVD apparatus 50 to the lowest point of the first jet hole 61 (in other words, the height d1 from the rake face) is 3 mm to 15 mm or less, based on the height position HP of the rake face of the substrate 2 closest to it in the CVD apparatus 50. Figure 15 , 16 In contrast, the second jet hole 62 is set such that the distance from the height position HP of the rake face of the substrate 2 closest to it within the CVD apparatus 50 to the lowest point of the second jet hole 62 (in other words, the height d2 (not shown) from the rake face) is 0 mm to 2 mm or less. Figure 15 ,17 Therefore, since the second injection hole 62 is relatively close to the cutting edge region of the substrate, the TiCl4 gas ejected from the second injection hole 62 is relatively easy to deposit onto the cutting edge region, but relatively difficult to deposit onto the rake face. As a result, the SiCl4 gas ejected from the first injection hole 61 is relatively easy to deposit onto the rake face. In addition, the flow rate of SiCl4 gas in the first injection hole is set to be 1.0 ml / min or more and less than 6.0 ml / min. Therefore, excessive deposition of SiCl4 can be suppressed, especially on the rake face. Thus, it is possible to achieve "the TiSiCN layer has a first TiSiCN layer located on the rake face and a second TiSiCN layer located in the cutting edge region, the composition of the first TiSiCN layer being Ti (1-Xr) Si Xr CN, the composition of the second TiSiCN layer is Ti (1-Xe) Si Xe CN, where Xr and Xe are both above 0.010 and below 0.100, and satisfy the relationship Xr-Xe≥0.003. This is the result of the inventors' in-depth research and is a new discovery.

[0178] (Conditions for forming layered structures)

[0179] In this process, when the nozzle 56 further has another inlet (not shown), the composition of the gas ejected from the first injection hole can be SiCl4, H2, and N2, the composition of the gas ejected from the second injection hole can be TiCl4, H2, and N2, and the composition of the gas ejected from the third injection hole can be CH3CN and H2. Thus, the TiSiCN layer is composed of multiple hard particles, which can have a layered structure formed by alternating layers with relatively high silicon concentration and layers with relatively low silicon concentration.

[0180] (Conditions for adjusting the periodic width of layered structures)

[0181] In this process, the rotation speed of the nozzle can be set to 1 rpm or more and 20 rpm or less. This allows the "average value of the period width of the layered structure" to be adjusted to a desired range. Furthermore, the rotation speed of the nozzle is preferably 1.5 rpm or more and 9.0 rpm or less. This allows the "average value of the period width of the layered structure" to be "3 nm or more and 20 nm or less".

[0182] (Conditions for setting the TiSiCN layer as a columnar structure)

[0183] In this process, the film-forming temperature can be maintained between 800°C and 860°C. This allows the TiSiCN layer to have a columnar structure.

[0184] (Conditions for adjusting the proportion of cubic crystal structure in the TiSiCN layer)

[0185] In this process, the furnace pressure can be set to between 10 mbar and 65 mbar. This allows the percentage of cubic crystal structure in the TiSiCN layer to be adjusted to the desired range.

[0186] (Conditions for adjusting the thickness of the TiSiCN layer)

[0187] In this process, the film formation time can be set to 2 hours or more and 25 hours or less. This allows the thickness of the TiSiCN layer to be adjusted to a desired range. Furthermore, the film formation time is preferably 4.0 hours or more and 20.0 hours or less. This allows the thickness of the TiSiCN layer to be 2.0 μm or more and 15 μm or less.

[0188] (Other conditions)

[0189] In the formation of the TiSiCN layer, the total gas flow rate of the reaction gas can be set to, for example, 120–200 L / min. Here, “total gas flow rate” refers to the ideal gas under standard conditions (0°C, 1 atm), representing the total volumetric flow rate introduced into the CVD furnace per unit time.

[0190] The coating formed by the second process described above includes a TiSiCN layer, which has a first TiSiCN layer located on the rake face and a second TiSiCN layer located in the cutting edge region. The first TiSiCN layer is composed of Ti... (1-Xr) Si Xr CN, the composition of the second TiSiCN layer is Ti (1-Xe) Si Xe CN, where Xr and Xe are both greater than 0.010 and less than 0.100, and satisfy the relationship Xr-Xe≥0.003.

[0191] <Other processes>

[0192] Based on the processes described above, surface treatment processes such as surface grinding and shot peening can be performed.

[0193] When the coating includes other layers (such as a base layer), these layers can be formed using methods known in the past.

[0194] Example

[0195] This embodiment will be further described in detail through examples. However, this embodiment is not limited to these examples.

[0196] [Example 1]

[0197] Making Cutting Tools

[0198] <Step 1>

[0199] As a substrate, a raw material powder consisting of a turning cutting tool made of cemented carbide, comprising Co (6wt%), VC (0.2wt%), Cr3C2 (0.4wt%), and WC (remaining) is uniformly mixed, pressed into a predetermined shape, and then sintered at 1300-1500°C for 1-2 hours to obtain a substrate of CNMG120408N-GU (manufactured by Sumitomo Electric Industries, Ltd.).

[0200] <Other processes (processes that form the base layer)>

[0201] To fabricate cutting tools for samples 1-1 to 1-12, 1-12-2, and 1-101 to 1-104, a substrate layer (TiN layer) was formed on the surface of each of the aforementioned substrates. Specifically, the substrates were placed in the reactor of a chemical vapor deposition apparatus, and the substrate layer was formed on the substrates by chemical vapor deposition. Furthermore, the formation conditions of the substrate layer are described in Table 1 below.

[0202]

[0203] <Second Process>

[0204] A coating was formed on the surface of each of the substrates obtained above. Specifically, the coating was formed on the substrate by chemical vapor deposition (CVD) by placing the substrate in the reactor of a CVD apparatus. Furthermore, the coating formation conditions are described in Table 2 below.

[0205]

[0206] <Other processes (processes that form intermediate and surface layers)>

[0207] To prepare cutting tools for samples 1-1 to 1-12-1 and 1-101 to 1-104, an intermediate layer (TiCNO layer) and a surface layer (Al2O3 layer) were formed on the surface of each of the aforementioned TiSiCN layers. Specifically, by placing each sample in the reactor of a chemical vapor deposition apparatus, chemical vapor deposition was performed under the conditions for forming the intermediate layer as described in Table 3 to form an intermediate layer on the TiSiCN layer. Then, chemical vapor deposition was performed under the conditions for forming the surface layer as described in Table 4 to form a surface layer on the intermediate layer.

[0208]

[0209]

[0210]

[0211] By performing the above procedures, cutting tools with the configurations shown in Table 5 for samples 1-1 to 1-12-3 and 1-101 to 1-104 were produced.

[0212] "evaluate"

[0213] For each sample's cutting tool, the average values ​​of Xr, Xe, A:B, the periodic width of the layered structure, whether the TiSiCN layer is a columnar structure, the content of cubic crystal structure, and the thickness of the TiSiCN layer were measured.

[0214] <Determination of Xr and Xe>

[0215] For the cutting tools of specimens 1-1 to 1-12-3 and 1-101 to 1-104, Xr was determined using the method described in Embodiment 1. The results are recorded in the "Xr (rake face)" column of Table 2. Furthermore, for the cutting tools of specimens 1-1 to 1-12 and 1-101 to 1-104, Xe was determined using the method described in Embodiment 1. The results are recorded in the "Xe (cutting edge)" column of Table 5.

[0216] <Determination of A:B>

[0217] For the cutting tools of samples 1-1 to 1-12-3 and 1-101 to 1-104, the A:B ratio in the first TiSiCN layer was determined using the method described in Embodiment 1. As a result, it was confirmed that for all the cutting tools of samples 1-1 to 1-12-3 and 1-101 to 1-104, the A:B ratio in the first TiSiCN layer was A:B = 1:0.8 to 1.1. Furthermore, for the cutting tools of samples 1-1 to 1-12-3 and 1-101 to 1-104, the A:B ratio in the second TiSiCN layer was determined using the method described in Embodiment 1. As a result, it was confirmed that for all the cutting tools of samples 1-1 to 1-12-3 and 1-101 to 1-104, the A:B ratio in the second TiSiCN layer was A:B = 1:0.8 to 1.1.

[0218] <Determination of the average value of the periodic width of the layered structure>

[0219] For the cutting tools of samples 1-1 to 1-12-3 and 1-101 to 1-104, the average value of the period width of the layered structure was determined by the method described in Embodiment 1. The results are recorded in the "Average value of period width [nm]" column of Table 5.

[0220] <Determination of whether the TiSiCN layer has a columnar structure>

[0221] For the cutting tools of samples 1-1 to 1-12-3 and 1-101 to 1-104, it was determined whether the TiSiCN layer had a columnar structure using the method described in Embodiment 1. The results obtained are recorded in the "Sectional Structure" column of Table 5. In the "Sectional Structure" column of Table 5, "columnar structure" means "the TiSiCN layer has a columnar structure" (in other words, the average aspect ratio of the hard particles is 3 or more), and "granular structure" means "the TiSiCN layer does not have a columnar structure" (in other words, the average aspect ratio of the hard particles is less than 3).

[0222] <Determination of the content of cubic crystal structure in TiSiCN layer>

[0223] For the cutting tools of samples 1-1 to 1-12-3 and 1-101 to 1-104, the content of cubic crystal structure in the TiSiCN layer was determined by the method described in Embodiment 1. The results are recorded in the "Content of cubic crystal [volume %]" column of Table 5.

[0224] <Determination of the thickness of the substrate layer, the TiSiCN layer, the intermediate layer, and the surface layer>

[0225] For the cutting tools of samples 1-1 to 1-12, 1-12-2, and 1-101 to 1-104, the thickness of the substrate layer was determined using the method described in Embodiment 1. The results are recorded in the "Thickness of Substrate Layer [μm]" column of Table 5. For the cutting tools of samples 1-1 to 1-12-3 and 1-101 to 1-104, the thickness of the TiSiCN layer was determined using the method described in Embodiment 1. The results are recorded in the "Thickness of TiSiCN Layer [μm]" column of Table 5. For the cutting tools of samples 1-1 to 1-12-1 and 1-101 to 1-104, the thickness of the intermediate layer was determined using the method described in Embodiment 1. The results are recorded in the "Thickness of Intermediate Layer [μm]" column of Table 5. For the cutting tools of samples 1-1 to 1-12-1 and 1-101 to 1-104, the thickness of the surface layer was determined using the method described in Embodiment 1. The results obtained are recorded in the "Surface layer thickness [μm]" column of Table 5.

[0226] <Cutting Test>

[0227] Using cutting tools of samples 1-1 to 1-12-3 and 1-101 to 1-104, the cutting time until the flank wear (Vb) reached 0.20 mm was measured under the following cutting conditions, and the final damage morphology of the cutting edge was observed. The results are recorded in the "Tool Life [minutes]" column of Table 5. The longer the cutting time, the longer the tool life.

[0228] (Cutting conditions)

[0229] Workpiece to be machined: SCM415 round bar

[0230] Circular speed: 200m / min

[0231] Feed rate: 0.3 mm / rev

[0232] Cut depth: 1.5mm

[0233] Cutting fluid: Available

[0234] This cutting condition is equivalent to intermittent turning of steel.

[0235] <Results>

[0236] The cutting tools of specimens 1-1 to 1-12-3 correspond to the examples. On the other hand, specimens 1-101 to 1-104 correspond to the comparative examples. It has been confirmed that the cutting tools of specimens 1-1 to 1-12-3 (examples) have a longer tool life in intermittent turning operations involving steel compared to the cutting tools of specimens 1-101 to 1-104 (comparative examples).

[0237] [Example 2]

[0238] Making Cutting Tools

[0239] <Step 1>

[0240] The same substrates as those used in samples 1-1 to 1-12-3 and 1-101 to 1-104 were prepared.

[0241] <Other processes (processes that form the base layer)>

[0242] To fabricate cutting tools for samples 2-1 to 2-11, 2-11-2, and 2-101 to 2-104, a substrate layer (TiN layer) was formed on the surface of each of the aforementioned substrates. Specifically, the substrate was placed in the reactor of a chemical vapor deposition apparatus, and the substrate layer was formed on the substrate by chemical vapor deposition. Furthermore, the formation conditions of the substrate layer are described in Table 6 below.

[0243]

[0244] <Second Process>

[0245] For each of the substrates obtained above, a coating is formed on its surface. Specifically, the coating is formed on the substrate by chemical vapor deposition (CVD) by placing the substrate in the reactor of a CVD apparatus. Furthermore, the coating formation conditions are described in Table 7 below.

[0246]

[0247] <Other processes (processes that form intermediate and surface layers)>

[0248] To prepare cutting tools for samples 2-1 to 2-11-1 and 2-101 to 2-104, an intermediate layer (TiCNO layer) and a surface layer (Al2O3 layer) were formed on the surface of each of the aforementioned TiSiCN layers. Specifically, each sample was placed in the reactor of a chemical vapor deposition apparatus, and chemical vapor deposition was performed under the conditions for forming the intermediate layer as described in Table 8. After forming the intermediate layer on the TiSiCN layer, chemical vapor deposition was performed under the conditions for forming the surface layer as described in Table 9, thereby forming the surface layer on the intermediate layer.

[0249]

[0250]

[0251]

[0252] By performing the above procedures, cutting tools with the configurations shown in Table 10 for samples 2-1 to 2-11-3 and 2-101 to 2-104 were produced.

[0253] "evaluate"

[0254] For each sample's cutting tool, the average values ​​of Xr, Xe, A:B, the periodic width of the layered structure, whether the TiSiCN layer is a columnar structure, the content of cubic crystal structure, and the thickness of the TiSiCN layer were measured.

[0255] <Determination of Xr and Xe>

[0256] For the cutting tools of samples 2-1 to 2-11-3 and 2-101 to 2-104, Xr was determined using the method described in Embodiment 1. The results are recorded in the "Xr (rake face)" column of Table 10. Furthermore, for the cutting tools of samples 2-1 to 2-11-3 and 2-101 to 2-104, Xe was determined using the method described in Embodiment 1. The results are recorded in the "Xe (cutting edge)" column of Table 10.

[0257] <Determination of A:B>

[0258] For the cutting tools of samples 2-1 to 2-11, and 2-101 to 2-104, the A:B ratio was determined using the method described in Embodiment 1. As a result, it was confirmed that for all the cutting tools of samples 2-1 to 2-11, and 2-101 to 2-104, the A:B ratio was A:B = 1:0.8 to 1.1. Furthermore, for the cutting tools of samples 2-1 to 2-11, and 2-101 to 2-104, the A:B ratio in the second TiSiCN layer was determined using the method described in Embodiment 1. As a result, it was confirmed that for all the cutting tools of samples 2-1 to 2-11, and 2-101 to 2-104, the A:B ratio in the second TiSiCN layer was A:B = 1:0.8 to 1.1.

[0259] <Determination of the average value of the periodic width of the layered structure>

[0260] For the cutting tools of samples 2-1 to 2-11-3 and 2-101 to 2-104, the average value of the period width of the layered structure was determined by the method described in Embodiment 1. The results are recorded in the "Average value of period width [nm]" column of Table 10.

[0261] <Determination of whether the TiSiCN layer has a columnar structure>

[0262] For the cutting tools of samples 2-1 to 2-11-3 and 2-101 to 2-104, it was determined whether the TiSiCN layer had a columnar structure using the method described in Embodiment 1. The results are recorded in the "Sectional Structure" column of Table 10. In the "Sectional Structure" column of Table 10, "columnar structure" means "the TiSiCN layer has a columnar structure" (in other words, the average aspect ratio of the hard particles is 3 or more), and "granular structure" means "the TiSiCN layer does not have a columnar structure" (in other words, the average aspect ratio of the hard particles is less than 3).

[0263] <Determination of the content of cubic crystal structure in TiSiCN layer>

[0264] For the cutting tools of samples 2-1 to 2-11-3 and 2-101 to 2-104, the content of cubic crystal structure in the TiSiCN layer was determined by the method described in Embodiment 1. The results are recorded in the "Content of cubic crystal [volume %]" column of Table 10.

[0265] <Determination of the thickness of the substrate layer, the TiSiCN layer, the intermediate layer, and the surface layer>

[0266] For the cutting tools of samples 2-1 to 2-11, 2-11-2, and 2-101 to 2-104, the thickness of the substrate layer was determined using the method described in Embodiment 1. The results are recorded in the "Thickness of Substrate Layer [μm]" column of Table 10. For the cutting tools of samples 2-1 to 2-11-3 and 2-101 to 2-104, the thickness of the TiSiCN layer was determined using the method described in Embodiment 1. The results are recorded in the "Thickness of TiSiCN Layer [μm]" column of Table 10. For the cutting tools of samples 2-1 to 2-11-1 and 2-101 to 2-104, the thickness of the intermediate layer was determined using the method described in Embodiment 1. The results are recorded in the "Thickness of Intermediate Layer [μm]" column of Table 10. For the cutting tools of samples 2-1 to 2-11-1 and 2-101 to 2-104, the thickness of the surface layer was determined using the method described in Embodiment 1. The results obtained are recorded in the "Surface layer thickness [μm]" column of Table 10.

[0267] <Cutting Test>

[0268] Using cutting tools of samples 2-1 to 2-11-3 and 2-101 to 2-104, the cutting time until the flank wear (Vb) reached 0.20 mm was measured under the following cutting conditions, and the final damage morphology of the cutting edge was observed. The results are recorded in the "Tool Life [minutes]" column of Table 10. The longer the cutting time, the longer the tool life.

[0269] (Cutting conditions)

[0270] Workpiece to be cut: S50C round bar

[0271] Circular speed: 220m / min

[0272] Feed rate: 0.3 mm / rev

[0273] Cut depth: 1.5mm

[0274] Cutting fluid: Available

[0275] This cutting condition is equivalent to intermittent turning of steel.

[0276] <Results>

[0277] The cutting tools of specimens 2-1 to 2-11-3 correspond to the examples. On the other hand, specimens 2-101 to 2-104 correspond to the comparative examples. It has been confirmed that the cutting tools of specimens 2-1 to 2-11-3 (examples) have a longer tool life in intermittent turning operations involving steel compared to the cutting tools of specimens 2-101 to 2-104 (comparative examples).

[0278] [Example 3]

[0279] Making Cutting Tools

[0280] <Step 1>

[0281] The same substrates as those used in samples 1-1 to 1-12-3 and 1-101 to 1-104 were prepared.

[0282] <Other processes (processes that form the base layer)>

[0283] To fabricate cutting tools for samples 3-1 to 3-10, 3-10-2, and 3-101 to 3-104, a substrate layer (TiN layer) was formed on the surface of each of the aforementioned substrates. Specifically, the substrate was placed in the reactor of a chemical vapor deposition apparatus, and the substrate layer was formed on the substrate by chemical vapor deposition. Furthermore, the formation conditions of the substrate layer are described in Table 11 below.

[0284]

[0285] <Second Process>

[0286] A coating was formed on the surface of each of the substrates obtained above. Specifically, the coating was formed on the substrate by chemical vapor deposition (CVD) by placing the substrate in the reactor of a CVD apparatus. Furthermore, the coating formation conditions are described in Table 12 below.

[0287]

[0288] <Other processes (processes that form intermediate and surface layers)>

[0289] To prepare cutting tools for samples 3-1 to 3-10-1 and 3-101 to 3-104, an intermediate layer (TiCNO layer) and a surface layer (Al2O3 layer) were formed on the surface of each of the aforementioned TiSiCN layers. Specifically, by placing each sample in the reactor of a chemical vapor deposition apparatus, chemical vapor deposition was performed under the intermediate layer formation conditions listed in Table 13 to form an intermediate layer on the TiSiCN layer, and then chemical vapor deposition was performed under the surface layer formation conditions listed in Table 14 to form a surface layer on the intermediate layer.

[0290]

[0291]

[0292]

[0293] By performing the above procedures, cutting tools with the configurations shown in Table 15, samples 3-1 to 3-10-3 and 3-101 to 3-104, were produced.

[0294] "evaluate"

[0295] For each sample, the average values ​​of Xr, Xe, A:B, the period width of the layered structure, whether the TiSiCN layer is a columnar structure, the content of cubic crystal structure, and the thickness of the TiSiCN layer were measured using the cutting tool.

[0296] <Determination of Xr and Xe>

[0297] For the cutting tools of samples 3-1 to 3-10-3 and 3-101 to 3-104, Xr was determined using the method described in Embodiment 1. The results are recorded in the "Xr (rake face)" column of Table 15. Furthermore, for the cutting tools of samples 3-1 to 3-10-3 and 3-101 to 3-104, Xe was determined using the method described in Embodiment 1. The results are recorded in the "Xe (cutting edge)" column of Table 15.

[0298] <Determination of A:B>

[0299] For the cutting tools of samples 3-1 to 3-10-3, and 3-101 to 3-104, the A:B ratio was determined using the method described in Embodiment 1. As a result, it was confirmed that for all the cutting tools of samples 3-1 to 3-10-3, and 3-101 to 3-104, the A:B ratio was A:B = 1:0.8 to 1.1. Furthermore, for the cutting tools of samples 3-1 to 3-10-3, and 3-101 to 3-104, the A:B ratio in the second TiSiCN layer was determined using the method described in Embodiment 1. As a result, it was confirmed that for all the cutting tools of samples 3-1 to 3-10-3, and 3-101 to 3-104, the A:B ratio in the second TiSiCN layer was A:B = 1:0.8 to 1.1.

[0300] <Determination of the average value of the periodic width of the layered structure>

[0301] For the cutting tools of samples 3-1 to 3-10-3 and 3-101 to 3-104, the average value of the period width of the layered structure was determined by the method described in Embodiment 1. The results are recorded in the "Average value of period width [nm]" column of Table 15.

[0302] <Determination of whether the TiSiCN layer has a columnar structure>

[0303] For the cutting tools of samples 3-1 to 3-10-3 and 3-101 to 3-104, the method described in Embodiment 1 was used to determine whether the TiSiCN layer had a columnar structure. The results obtained are recorded in the "Sectional Structure" column of Table 15. In the "Sectional Structure" column of Table 15, "columnar structure" means "the TiSiCN layer has a columnar structure" (in other words, the average aspect ratio of the hard particles is 3 or more), and "granular structure" means "the TiSiCN layer does not have a columnar structure" (in other words, the average aspect ratio of the hard particles is less than 3).

[0304] <Determination of the content of cubic crystal structure in TiSiCN layer>

[0305] For the cutting tools of samples 3-1 to 3-10-3 and 3-101 to 3-104, the content of cubic crystal structure in the TiSiCN layer was determined by the method described in Embodiment 1. The results are recorded in the "Cubic crystal content [volume %]" column of Table 15.

[0306] <Determination of the thickness of the substrate layer, the TiSiCN layer, the intermediate layer, and the surface layer>

[0307] For the cutting tools of samples 3-1 to 3-10, 3-10-2, and 3-101 to 3-104, the thickness of the substrate layer was determined using the method described in Embodiment 1. The results are recorded in the "Thickness of Substrate Layer [μm]" column of Table 15. For the cutting tools of samples 3-1 to 3-10-3 and 3-101 to 3-104, the thickness of the TiSiCN layer was determined using the method described in Embodiment 1. The results are recorded in the "Thickness of TiSiCN Layer [μm]" column of Table 15. For the cutting tools of samples 3-1 to 3-10-1 and 3-101 to 3-104, the thickness of the intermediate layer was determined using the method described in Embodiment 1. The results are recorded in the "Thickness of Intermediate Layer [μm]" column of Table 15. For the cutting tools of samples 3-1 to 3-10-1 and 3-101 to 3-104, the thickness of the surface layer was determined using the method described in Embodiment 1. The results obtained are recorded in the "Surface layer thickness [μm]" column of Table 15.

[0308] <Cutting Test>

[0309] Using cutting tools of samples 3-1 to 3-10-3 and 3-101 to 3-104, the cutting time until the flank wear (Vb) reached 0.20 mm under the following cutting conditions was measured, and the final damage morphology of the cutting edge was observed. The results are recorded in the "Tool Life [minutes]" column of Table 15. The longer the cutting time, the longer the tool life.

[0310] (Cutting conditions)

[0311] Workpiece to be cut: SUJ2 round bar

[0312] Circular speed: 200m / min

[0313] Feed rate: 0.3 mm / rev

[0314] Cut depth: 1.5mm

[0315] Cutting fluid: Available

[0316] This cutting condition is equivalent to intermittent turning of steel.

[0317] <Results>

[0318] The cutting tools of specimens 3-1 to 3-10-3 correspond to the examples. On the other hand, specimens 3-101 to 3-104 correspond to the comparative examples. It has been confirmed that the cutting tools of specimens 3-1 to 3-10-3 (examples) have a longer tool life in intermittent turning operations involving steel compared to the cutting tools of specimens 3-101 to 3-104 (comparative examples).

[0319] As can be seen from the above, the cutting tools of samples 1-1~1-12-3, 2-1~2-11-3, and 3-1~3-10-3 also have a long tool life in intermittent turning operations involving steel.

[0320] As described above, the implementation methods and embodiments of this disclosure have been described. However, it is originally intended that the above implementation methods and embodiments be appropriately combined or modified in various ways.

[0321] The embodiments and examples disclosed herein should be considered exemplary in all respects, and not restrictive. The scope of the invention is defined not by the foregoing embodiments and examples, but by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0322] Explanation of reference numerals in the attached figures

[0323] 1: Cutting tools;

[0324] 2: Substrate;

[0325] 2a: Rake face;

[0326] 2b: Back face;

[0327] 2c: Cutting edge;

[0328] 3: Lamination;

[0329] 11: Front face;

[0330] 12: Back face;

[0331] 13: Cutting edge;

[0332] 30: TiSiCN layer;

[0333] 31: Other layers;

[0334] 32: Basal layer;

[0335] 33: Intermediate layer;

[0336] 34: Surface layer;

[0337] 50: CVD device;

[0338] 52: Substrate assembly fixture;

[0339] 53: Reaction vessel;

[0340] 54: Temperature control device;

[0341] 55, 57: Inlet / Outlet;

[0342] 59: Exhaust pipe;

[0343] 60: Exhaust port;

[0344] 61: First injection hole;

[0345] 62: Second injection hole;

[0346] 63: Third injection hole;

[0347] E: The edge that forms the boundary between the rake face and the flank face;

[0348] D: Distance from the edge or imaginary edge (straight-line distance);

[0349] R: An imaginary plane containing the rake face;

[0350] F: An imaginary plane containing the back face;

[0351] EE: The imaginary edge formed by the intersection of imaginary plane R and imaginary plane F;

[0352] EF: The imaginary boundary line that forms the boundary between the back face and the imaginary plane F;

[0353] ER: The imaginary boundary line that forms the boundary of the deviation between the rake face and the imaginary plane R;

[0354] L1: The line that bisects the corner;

[0355] L2: A line perpendicular to the cutting edge of the straight section;

[0356] T, H: Arrow;

[0357] HP: Height position of the rake face of the substrate.

Claims

1. A cutting tool, wherein the cutting tool comprises a substrate and a coating disposed on the substrate, wherein, The cutting tool includes: Front face; The flank face connected to the rake face; and The cutting edge region formed by the boundary portion of the rake face and the flank face. The coating comprises a TiSiCN layer. The TiSiCN layer has: The first TiSiCN layer located on the rake face; and The second TiSiCN layer is located in the cutting edge region. The first TiSiCN layer has a composition of Ti (1-Xr) Si Xr CN, The second TiSiCN layer has a composition of Ti (1-Xe) Si Xe CN, The value of Xr is greater than or equal to 0.013 and less than or equal to 0.100, and the value of Xe is greater than or equal to 0.010 and less than or equal to 0.097, and the relationship Xr-Xe≥0.003 is satisfied.

2. The cutting tool according to claim 1, wherein, The TiSiCN layer is composed of multiple hard particles. The hard particles have a layered structure consisting of alternating layers with relatively high silicon concentration and layers with relatively low silicon concentration.

3. The cutting tool of claim 2, wherein, The total number of layers with relatively high silicon concentration and layers with relatively low silicon concentration is between 10 and 1000.

4. The cutting tool according to claim 2 or 3, wherein, The average period width of the layered structure is between 3 nm and 20 nm.

5. The cutting tool according to claim 1 or 2, wherein, The TiSiCN layer has a columnar structure.

6. The cutting tool according to claim 1 or 2, wherein, The TiSiCN layer has a cubic crystal structure with a volume percentage of over 90%.

7. The cutting tool according to claim 1 or 2, wherein, The TiSiCN layer has a cubic crystal structure with a volume percentage of 90% to 100% or more.

8. The cutting tool according to claim 1 or 2, wherein, The thickness of the TiSiCN layer is between 2.0 μm and 15 μm.

9. The cutting tool according to claim 1 or 2, wherein, The thickness of the TiSiCN layer is between 3.0 μm and 14 μm.

10. The cutting tool according to claim 1 or 2, wherein, The thickness of the TiSiCN layer is between 4.0 μm and 13 μm.

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