Coated cutting tool

Abstract

This invention relates to a coated cutting tool having at least one rake face and at least one flank face and a cutting edge therebetween. The coated cutting tool comprises a substrate and a coating comprising a (Ti,Al)N layer. The (Ti,Al)N layer is a single monolayer or a multilayer of two or more alternating (Ti,Al)N sublayers with different compositions. The total atomic ratio of the (Ti,Al)N layer, Al / (Ti+Al), is >0.67 but ≤0.85. The (Ti,Al)N layer exhibits a plane strain modulus distribution along a direction perpendicular to the cutting edge on the rake face and / or the flank face. The plane strain modulus at a point 0.5 mm away from the cutting edge is greater than 85% of the plane strain modulus at the cutting edge, and the plane strain modulus at the cutting edge is ≥450 GPa.

Description

Technical Field

[0001] The present invention relates to a coated cutting tool having a coating comprising a (Ti,Al)N layer with a total atomic ratio Al / (Ti+Al) > 0.67 but ≤ 0.85. Background Technology

[0002] There has always been a desire to improve cutting tools used in metal machining, extending their service life and enabling them to withstand higher cutting speeds and / or other increasingly demanding cutting operations. Typically, cutting tools for metal machining contain a hard base material, such as cemented carbide, with a thin, hard, wear-resistant coating.

[0003] When depositing wear-resistant coatings, the commonly used methods are chemical vapor deposition (CVD) or physical vapor deposition (PVD). Both methods offer limitations in the coating properties they can provide. Even when coatings with the same chemical composition are deposited using either method, their properties, such as internal residual stress, density, crystallinity, and crystal size, will vary. Therefore, their characteristics and performance in end-use metal cutting applications will differ.

[0004] Wear-resistant coatings typically consist of one or more layers of metal nitrides, metal carbonitrides, or metal oxides. The source of the metal elements in coatings deposited via PVD is the so-called "target" within the PVD reactor. Various PVD methods exist, with the main categories being cathodic arc evaporation and magnetron sputtering. Within the general term "magnetron sputtering," there are also different methods that differ from each other, such as dual magnetron sputtering (DMS) and high-power pulsed magnetron sputtering (HIPIMS).

[0005] Titanium aluminum nitride (Ti,Al)N coatings deposited by PVD and their use as wear-resistant coatings in metal cutting tools are well known. One type of PVD (Ti,Al)N coating is a monolayer, in which the (Ti,Al)N composition is substantially the same throughout the layer. A monolayer coating is provided when more than one target used in the deposition process has the same Ti:Al ratio. Another type of PVD (Ti,Al)N coating is a multilayer, in which sublayers of (Ti,Al)N with different compositions exist within the layers. Such multilayers can be provided when at least two of the targets used in the deposition process have different Ti:Al ratios, such that sublayers of different compositions are deposited alternately as the substrate rotates in the chamber. A special type of multilayer is the nanomultilayer, in which the thickness of a single layer can be as low as a few nanometers.

[0006] The advantageous wear resistance of (Ti,Al)N coatings stems from their superior thermomechanical properties, specifically those of (Ti,Al)N exhibiting a face-centered cubic (fcc)B1 crystal conformation. Such (Ti,Al)N coatings combine high oxidation resistance with significant age hardening during amplitude modulation decomposition.

[0007] Within the cubic conformation, it is generally believed that increasing the Al content of each component can further improve the wear resistance, adhesive wear resistance, and oxidation resistance of (Ti,Al)N. However, relative to the mechanically weaker and more compliant hexagonal B4 wurtzite conformation, the free enthalpy of B1-(Ti,Al)N increases significantly with increasing Al concentration. This makes obtaining a preferred cubic structure increasingly difficult. Beyond the Al concentration relative to the coating metal portion (i.e., the Al content in the Ti+Al content) ≈ 67%, the wurtzite structure is thermodynamically more stable than its cubic counterpart, which typically results in a mixture of deposited phases or even a hexagonal coating with relatively poor mechanical properties.

[0008] In existing research, lower Al contents in (Ti,Al)N, such as ≤60 atomic% of Al+Ti, typically give a single-phase cubic structure, while in (Ti,Al)N, Al contents >67 atomic% of Al+Ti, and especially >70 atomic% of Al+Ti, a large number of hexagonal structures are observed. Specific limitations on the Al content levels used to give a single-phase cubic structure have been reported in existing research, but these vary to some extent depending on the deposition conditions, for example, during the PVD process.

[0009] One primary means of extending the phase field of a cubic B1 structure to higher Al concentrations is to increase ion bombardment during deposition. This phenomenon is typically observed around the cutting edge of a cutting tool, where the coating structure is generally significantly rougher and harder than at distances further from the cutting edge. Here, the local concentration of the electric field lines effectively causes an increase in the bias potential during deposition. Due to the increased kinetic energy of the incident ions, subcritical-sized hexagonal wurtzite B4 nuclei may be more easily re-sputtered from the surface, allowing more resistant cubic nuclei to grow into larger B1 grains. However, to ensure reliable performance in all applications and for all wear patterns, including crater wear, a predominantly cubic coating must be produced over a wide area around the cutting edge. That means a coating as far as 0.5 mm or even 1 mm from the cutting edge on both the flank and rake faces. Unfortunately, simply increasing the applied bias potential does not solve this requirement. This is again due to the localized increase in potential. Once the ion energy impacting the far cutting surface (0.5 mm or even 1 mm from the cutting edge) is high enough to stabilize the cubic deposition in that region, the increase in residual stress at the cutting edge caused by the increased ion bombardment leads to coating delamination.

[0010] In summary, the aforementioned limitations lead to the fact that commercially available and prior art (Ti,Al)N coatings can be classified into two groups. One group comprises (Ti,Al)N coatings with conventional Al content (defined here as Al content < 67% in Ti + Al content), characterized by a predominantly cubic structure throughout the cutting edge, thus exhibiting constant mechanical properties regardless of the measurement location. The second group comprises (Ti,Al)N coatings with high Al content (Al content ≥ 67% in Ti + Al content), which may partially exhibit a more cubic structure limited to the cutting edge, but otherwise constitute a mixture of cubic and hexagonal dispersed phases with unfavorable mechanical properties. Summary of the Invention

[0011] Purpose of the invention

[0012] One object of the present invention is to provide a coated cutting tool having a coating comprising a (Ti,Al)N layer with a total atomic ratio Al / (Ti+Al)>0.67 but ≤0.85, exhibiting excellent wear resistance, such as excellent flank wear resistance and / or excellent crater wear resistance. Summary of the Invention

[0014] A coated cutting tool for metal cutting is now provided to achieve the above-mentioned objectives. The coated cutting tool has at least one rake face and at least one flank face, and a cutting edge therebetween. The coated cutting tool comprises a substrate and a coating, the coating comprising a (Ti,Al)N layer, wherein the (Ti,Al)N layer is a single monolayer or a multilayer of two or more alternating (Ti,Al)N sublayers of different compositions, the total atomic ratio of the (Ti,Al)N layer being Al / (Ti+Al) > 0.67 but ≤ 0.85, wherein the (Ti,Al)N layer exhibits a plane strain modulus distribution along a direction perpendicular to the cutting edge on the rake face and / or the flank face, the plane strain modulus at a point 0.5 mm away from the cutting edge being greater than 85%, suitably greater than 90%, preferably greater than 95%, and the plane strain modulus at the cutting edge being ≥ 450 GPa.

[0015] The plane strain modulus at a point 0.5 mm away from the cutting edge is suitably up to 100% of the plane strain modulus at the cutting edge.

[0016] The cutting edge of the coated cutting tool is located between the rake face and the flank face. The cutting edge has a circular portion, as seen in the cross-sectional view of the cutting edge, and the term "cutting edge" herein refers to the position on the rake face and / or flank face of the coated cutting tool at the beginning of the circular portion.

[0017] In one embodiment, the plane strain modulus at a point 1 mm away from the cutting edge is greater than 85% of the plane strain modulus at the cutting edge, suitably greater than 90%, and preferably greater than 95%.

[0018] The plane strain modulus at a point 1 mm away from the cutting edge is suitably up to 100% of the plane strain modulus at the cutting edge.

[0019] In one embodiment, the (Ti,Al)N layer exhibits a hardness distribution along a direction perpendicular to the cutting edge on the rake face and / or flank face, wherein the hardness at a point 0.5 mm away from the cutting edge is greater than 85% of the hardness at the cutting edge, suitably greater than 90%, preferably greater than 95%, and the Vickers hardness at the cutting edge is ≥3000 HV (15 mN load).

[0020] The hardness at a point 0.5 mm away from the cutting edge is suitably up to 100% of the hardness at the cutting edge.

[0021] In one embodiment, the (Ti,Al)N layer exhibits a hardness distribution along a direction perpendicular to the cutting edge on the rake face and / or flank face, and the hardness at a point 1 mm away from the cutting edge is greater than 85% of the hardness at the cutting edge, suitably greater than 90%, preferably greater than 95%, and the Vickers hardness at the cutting edge is ≥3000 HV (15 mN load).

[0022] The hardness at a point 1 mm away from the cutting edge is appropriately up to 100% of the hardness at the cutting edge.

[0023] The plane strain modulus of the (Ti,Al)N layer at the cutting edge is suitably ≥475 GPa, preferably ≥490 GPa. The plane strain modulus of the (Ti,Al)N layer at the cutting edge is suitably 475-540 GPa, preferably 490-530 GPa.

[0024] The Vickers hardness of the (Ti,Al)N layer at the cutting edge is suitably ≥3200 HV (15 mN load), preferably ≥3500 HV (15 mN load). The Vickers hardness of the (Ti,Al)N layer at the cutting edge is suitably 3000-4400 HV (15 mN load), preferably 3500-4300 HV (15 mN load).

[0025] In one embodiment, the thickness of the (Ti,Al)N layer is 0.1-15 μm, preferably 0.5-12 μm, and most preferably 1-8 μm.

[0026] In one embodiment, the (Ti,Al)N layer exhibits a distribution of 111 misorientation angles, where the 111 misorientation angle is the ratio of the normal vector of the (Ti,Al)N layer surface to the normal vector closest to the (Ti,Al)N layer surface. <111> The cumulative frequency distribution of the 111 orientation difference angles between directions makes ≥60% of the 111 orientation difference angles less than 10 degrees.

[0027] If we exclude antiparallel directions / planes (e.g., -1-1-1 antiparallel to 111), then there are four unique sets of {111}-type planes ((111), (1-1-1), (-11-1), and (-1-11)) in a cubic crystal structure. They are at an angle of 70.5° to each other. If one of these planes is parallel to the (Ti,Al)N surface, i.e., the ideal 111 orientation, then the 111 orientation difference angle should be 0°, but there are still other {111}-type planes whose angle with the normal vector of the surface is greater than 0°. The 111 orientation difference angle in this paper refers to the minimum angle, i.e., the angle between the normal vector of the (Ti,Al)N layer and the normal vector closest to the (Ti,Al)N layer. <111> The angle between directions.

[0028] The distribution of the 111 orientation aberration angle can be determined by electron backscattering analysis (EBSD). However, the columnar grain width typically increases with increasing (Ti,Al)N layer thickness, especially for the first few micrometers of the (Ti,Al)N layer. If the grain width is too small, EBSD analysis may be unsuitable. Therefore, when the (Ti,Al)N layer thickness is less than 2 μm, if the grain size is considered too small for EBSD analysis, it is preferable to determine the distribution of the 111 orientation aberration angle by transmission electron microscopy (TEM). EBSD or TEM analysis is performed at a distance of 0.7 mm from the cutting edge.

[0029] The cumulative frequency distribution of the 111 orientation difference angles makes it suitable that ≥75%, preferably ≥90%, of the 111 orientation difference angles is less than 10 degrees.

[0030] The cumulative frequency distribution of the 111 orientation difference angles makes it suitable that 75% to 97%, preferably 90% to 95%, of the 111 orientation difference angles is less than 10 degrees.

[0031] The total atomic ratio Al / (Ti+Al) of the (Ti,Al)N layer is suitably 0.70-0.85, preferably 0.70-0.80, and most preferably 0.72-0.76.

[0032] In one implementation, the (Ti,Al)N layer is a single monolithic layer.

[0033] In one embodiment, the (Ti,Al)N layer is a multilayer consisting of two or more alternating (Ti,Al)N sublayer types that differ in composition, wherein the atomic ratio Al / (Ti+Al) of at least one (Ti,Al)N sublayer type is 0.50-0.67, preferably 0.55-0.67, most preferably 0.60-0.67, and the atomic ratio Al / (Ti+Al) of at least one (Ti,Al)N sublayer type is 0.70-0.90, preferably 0.75-0.90, most preferably 0.75-0.85.

[0034] In one embodiment, the (Ti,Al)N layer is a multilayer consisting of one or two (Ti,Al)N sublayer types with an atomic ratio Al / (Ti+Al) of 0.50-0.67, preferably 0.55-0.67, and most preferably 0.60-0.67, alternating with one or two (Ti,Al)N sublayer types with an atomic ratio Al / (Ti+Al) of 0.70-0.90, preferably 0.75-0.90, and most preferably 0.75-0.85.

[0035] In a preferred embodiment, the (Ti,Al)N layer is a multilayer consisting of alternating (Ti,Al)N sublayer types with an atomic ratio Al / (Ti+Al) of 0.50-0.67, preferably 0.55-0.67, and most preferably 0.60-0.67, and an atomic ratio Al / (Ti+Al) of 0.70-0.90, preferably 0.75-0.90, and most preferably 0.75-0.85.

[0036] The average thickness of the (Ti,Al)N sublayer type in the multilayer is suitably 1-100 nm, preferably 1.5-50 nm, and most preferably 2-20 nm.

[0037] In one embodiment, the ratio of the average thickness of different (Ti,Al)N sublayer types is 0.5 to 2, preferably 0.75 to 1.5.

[0038] In one embodiment, the (Ti,Al)N layer has a single-phase cubic B1 crystal structure at a distance of at least 0.5 mm, preferably at least 1 mm, from the point on the rake face and / or the flank face along a direction perpendicular to the cutting edge.

[0039] The determination of one or more crystal structures present in the (Ti,Al)N layer is appropriately performed by X-ray diffraction analysis or TEM analysis.

[0040] In one embodiment, the (Ti,Al)N layer shows only cubic (Ti,Al)N reflection in X-ray diffraction or TEM analysis within 1 mm of the cutting edge.

[0041] In one embodiment, the average columnar grain width of the (Ti,Al)N layer, measured at a distance of up to 2 μm from the lower interface of the (Ti,Al)N layer, is less than 175 nm, preferably less than 150 nm.

[0042] In one embodiment, the average columnar grain width of the (Ti,Al)N layer, measured at a distance of up to 2 μm from the lower interface of the (Ti,Al)N layer, is 80-175 nm, preferably 100-150 nm.

[0043] In one embodiment, an innermost layer of coating is present directly on the substrate beneath the (Ti,Al)N layer. This innermost layer is a nitride of one or more elements belonging to Groups 4, 5, or 6 of the periodic table, or a nitride of Al and one or more elements belonging to Groups 4, 5, or 6 of the periodic table. This innermost layer can at least partially serve as a bonding layer with the substrate to increase the overall adhesion of the coating to the substrate. Such bonding layers are commonly used in the art, and those skilled in the art should select a suitable one. Preferred alternatives to this innermost layer are TiN and (Ti)N. 1-x Al x N,x is suitably >0 but ≤0.67. The thickness of the innermost layer is suitably less than 3 μm. In one embodiment, the thickness of the innermost layer is 0.1-3 μm, preferably 0.2-1 μm.

[0044] In one embodiment, there is one or more other layers commonly used in cutting tool coatings combined with the (Ti,Al)N layer of the present invention. For example, nitrides of one or more elements belonging to Groups 4, 5, or 6 of the periodic table, or Al nitrides of one or more elements belonging to Groups 4, 5, or 6 of the periodic table. For example, (Ti... 1-y Al y For N layers, y is appropriately >0 but ≤0.67.

[0045] In one embodiment, the coating comprises a (Ti) layer with a thickness of 0.5-3 μm. 1-y Al y The inner layer is composed of (Ti,Al)N (0.25≤y≤0.67), followed by a (Ti,Al)N layer of the present invention with a thickness of 0.5-5μm.

[0046] The (Ti,Al)N layer according to the invention is deposited by PVD, i.e., the (Ti,Al)N layer is a PVD layer. Suitably, the (Ti,Al)N layer is a PVD layer deposited by a sputtering process, preferably a layer deposited by high-power pulsed magnetron sputtering (HIPIMS).

[0047] The substrate of the coated cutting tool can be any type commonly found in the field of cutting tools used in metal machining. Suitable substrates are selected from cemented carbide, cermet, cubic boron nitride (cBN), ceramics, polycrystalline diamond (PCD), and high-speed steel (HSS).

[0048] In a preferred embodiment, the substrate is a cemented carbide.

[0049] The coated cutting tool is suitably in the form of a cutting blade, drill bit, or end mill. Attached Figure Description

[0050] Figure 1 A schematic diagram showing one embodiment of a cutting tool as a milling insert.

[0051] Figure 2 A schematic diagram showing one embodiment of a cutting tool used as a turning insert.

[0052] Figure 3 A schematic diagram showing one embodiment of the cutting edge of a cutting tool.

[0053] Figure 4 A schematic cross-sectional view showing one embodiment of the coated cutting tool of the present invention, wherein the substrate and coating are shown.

[0054] Figure 5 Referring to Example 1, the hardness distribution of (Ti,Al)N coatings deposited under different total pressures along the distance from the cutting edge is shown.

[0055] Figure 6 Referring to Example 1, the plane strain modulus distribution of (Ti,Al)N coatings deposited under different total pressures along the distance from the cutting edge is shown.

[0056] Figure 7 Referring to Example 2, the plane strain modulus distribution of (Ti,Al)N coatings deposited at different temperatures along the distance from the cutting edge is shown.

[0057] Figure 8 Referring to Example 2, the hardness distribution of (Ti,Al)N coatings deposited at different temperatures along the distance from the cutting edge is shown.

[0058] Figure 9Referring to Example 4, the plane strain modulus distribution of a single monolayer (Ti,Al)N coating “Sample 6” along the distance from the cutting edge is shown.

[0059] Figure 10 Referring to Example 4, the hardness distribution of a single monolayer (Ti,Al)N coating “Sample 6” along the distance from the cutting edge is shown.

[0060] Figure 11 Referring to Example 5, and showing the distribution of plane strain modulus along the distance from the cutting edge on the rake face of (Ti,Al)N coated "Sample 7", "Sample 8" and "Sample 9" and (Ti,Al)N coated "Sample 10" according to the present invention, the distribution of plane strain modulus along the distance from the cutting edge is shown.

[0061] Figure 12 Referring to Example 5, the distribution of plane strain modulus along the distance from the cutting edge, measured on the flank face, is shown for "Sample 7", "Sample 8" and "Sample 9" and "Sample 10" of the (Ti,Al)N coating according to the invention.

[0062] Figure 13 Referring to Example 5, and showing the distribution of hardness along the distance from the cutting edge on the rake face of (Ti,Al)N coated "Sample 7", "Sample 8" and "Sample 9" and (Ti,Al)N coated "Sample 10" according to the present invention, the distribution of hardness is shown.

[0063] Figure 14 Referring to Example 5, and showing the distribution of hardness along the distance from the cutting edge on the flank face of (Ti,Al)N coated "Sample 7", "Sample 8" and "Sample 9" and (Ti,Al)N coated "Sample 10" according to the present invention, the distribution of hardness is shown.

[0064] Figure 15 The frequency distribution curve of the 111 orientation difference angle from electron backscatter diffraction (EBSD) analysis shows one embodiment of the present invention, “Sample 2a (Invention)”.

[0065] Figure 16 Frequency distribution curves of the 111 orientation difference angle from electron backscatter diffraction (EBSD) analysis of one embodiment of "Sample 6 (Invention)" of the present invention are shown.

[0066] Figure 17 This shows a transmission electron microscope (TEM) electron diffraction pattern of a (Ti,Al)N layer for one embodiment of the present invention, “Sample 2a (Invention)”. Detailed Implementation

[0067] Figure 1A schematic diagram showing one embodiment of a cutting tool (1) is shown, the cutting tool having a rake face (2), a flank face (3), and a cutting edge (4). In this embodiment, the cutting tool (1) is a milling insert. Figure 2 A schematic diagram showing one embodiment of a cutting tool (1) is shown, the cutting tool having a rake face (2), a flank face (3), and a cutting edge (4). In this embodiment, the cutting tool (1) is a turning insert.

[0068] Figure 3 A schematic diagram showing one embodiment of the cutting edge of a cutting tool. The cutting edge (4) is located at the intersection of the rake face (2) and the flank face (3). In the cross-sectional view, the cutting edge (4) has a rounded corner.

[0069] Figure 4 A schematic cross-sectional view showing one embodiment of the coated cutting tool of the present invention, the coated cutting tool having a substrate body (5) and a (Ti,Al)N coating (6).

[0070] method

[0071] Electron backscatter diffraction (EBSD):

[0072] EBSD measurements were performed on the flank face of the cutting tool sample at a distance of 50 μm from the cutting edge.

[0073] Prior to EBSD scanning, the surfaces of each sample were carefully polished using a colloidal silica suspension with a nominal grain size of 40 nm (Struers OPS 0.04 μm). This step was used to remove any roughness present on the surface of the deposited coating. No more than 100 nm of the top coating was removed through this process.

[0074] If the (Ti,Al)N layer is not the top layer of the coating, a suitable method such as polishing is used to remove the layer above the (Ti,Al)N layer so that a polished (Ti,Al)N surface is ultimately provided for EBSD scanning.

[0075] Electron diffraction patterns were acquired using a Zeiss CrossBeam 540FIB-SEM (Carl Zeiss Group, Upper Cohen, Germany) and an EDAX DigiView 5EBSD camera (EDAX, Mova, NJ, USA) with a standard sample tilt of 70° and a working distance of 5 mm. An electron beam accelerating voltage of 10–13 kV was used for acquisition. The mapping step size was 20 nm. The mapped region was 15.00 × 11.25 μm.

[0076] The measured crystal orientation data were indexed using EDAX TEAM software and further evaluated using EDAX OIM analysis software.

[0077] The cumulative frequency distribution of the 111 orientation difference angle is calculated as follows: For each point measurement of the total EBSD scan (representing the incremental surface area of ​​the entire analyzed surface region), the crystallographic direction perpendicular to the surface plane of the (Ti,Al)N layer originates from the measured absolute crystallographic orientation (i.e., the orientation data of the Euler angles).

[0078] Subsequently, the crystallographic direction was calculated to be closest to the nearest <111> The vector angle between the orientations. "Closest" refers to the smallest possible angle (among all four crystallographic equivalent possibilities) that includes the surface normal. <111> The orientation direction. This angle is defined as the 111 orientation difference angle. Since each measurement point constitutes an equal part of the analysis area, the relative frequency distribution of these angular orientation differences characterizes the overall degree of 111 surface texture.

[0079] Electron diffraction in transmission electron microscopy (TEM):

[0080] In the electron diffraction analyses presented in this paper, these were TEM measurements performed using a transmission electron microscope: a JEOL ARM 200F microscope, 200 kV. Only the coating contributes to the diffraction pattern using a selected area aperture. The TEM was performed using parallel illumination diffraction during selected area electron diffraction (SAED).

[0081] Cross-sectional analysis was performed on the sample, i.e., the incident electron beam was parallel to the film surface. To eliminate amorphization during sample preparation, different methods were used: i) classical preparation, including mechanical cutting, bonding, grinding, and ion polishing; and ii) cutting the sample using FIB and extracting it for final polishing. The analysis site was near the substrate, approximately 200 nm away.

[0082] SAED data for the sample was obtained. The SAED data provided the diffraction intensity distribution along a 111-ring centered at an angle corresponding to the coating normal. Normalized integrals were then performed at the 111-ring and -1-1-1-1-1 diffraction spots, respectively, to reach a 45-degree orientation difference angle. The two integrals were combined to form an intensity distribution curve. Intensity distribution data from both the 111-ring and -1-1-1-1 diffraction spots were used to increase the number of data points, thereby minimizing the signal-to-noise ratio.

[0083] The intensity at a specific orientation difference angle is proportional to the sample volume exhibiting that orientation difference. Therefore, the intensity distribution curve corresponds to the distribution at an orientation difference angle of 111. Accordingly, the cumulative intensity curve obtained from the intensity distribution curve corresponds to the cumulative frequency distribution at an orientation difference angle of 111.

[0084] X-ray diffraction:

[0085] X-ray diffraction patterns were acquired in tangential incidence mode (GID) using a diffractometer (PTS 3003) from Seifert / GE. Cu-Kα radiation and a multi-capillary lens (for generating a parallel beam) were used for analysis (40 kV high voltage, 40 mA current). The incident beam was defined by a 0.5 mm pinhole. An energy-dispersive detector (Meteor0D) was used for the diffraction beam path. Measurements were performed in tangential incidence mode (ω = 4°). The 2θ range was approximately 20°–80° with a step size of 0.03° and a counting time of 6 s.

[0086] Vickers hardness:

[0087] Vickers hardness was measured using a Picodentor HM500 from Helmut Fischer GmbH, Sindelfingen, Germany, via nanoindentation (load depth map). For measurement and calculation, the Oliver and Phar evaluation algorithm was applied, in which a diamond test piece is indented into the Vickers matrix, and a force-path curve is recorded during the measurement. The maximum load used was 15 mN (HV 0.0015), with each load increase and decrease period lasting 20 seconds. Hardness was calculated from this curve.

[0088] plane strain modulus:

[0089] The so-called plane strain modulus E, derived from nanoindentation, was obtained using the Oliver and Pharr method. ps This was used to characterize the elastic properties of the coated samples. Nanoindentation data was obtained from the indentations described above for Vickers hardness.

[0090] The 1mm distance from the cutting edge used in this article refers to the distance 1mm from the starting point of the cutting edge (i.e., the starting point of the chamfer).

[0091] Grain width:

[0092] The average (Ti,Al)N grain width was determined by evaluating the SEM cross-section using a three-dimensional line intersection method: a line mesh was overlaid onto the SEM micrograph, and the intersections of the lines with the grain boundary network were marked. The statistical distances between adjacent intersections reflected the size of the three-dimensional grains (see, for example, B. Ilschner, RFSinger, Werkstoffwissenschaften and Fertigungstechnik, Springer Berlin Heidelberg, 2016, ISBN: 978-3-642-53891-9). The SEM micrographs were taken on the flank face at a distance of approximately 0.7 μm from the cutting edge.

[0093] Example:

[0094] Example 1 (Influence of Total Pressure):

[0095] Using a composition of Ti 0.33 Al 0.67 The target and a component of Ti 0.20 Al 0.80 The target setup deposits a (Ti,Al)N layer onto a WC-Co matrix. The WC-Co matrix is ​​a square blade with a flat geometry for easier analysis of the coating. The matrix is ​​composed of 8 wt% Co and the balance WC.

[0096] The HIPIMS mode was used on a Hauzer Flexicoat 1000 apparatus. The total pressure was varied during three independent deposition processes while keeping all other conditions identical. Three different total pressures were tested: 0.505 Pa, 0.219 Pa, and 0.167 Pa. The aim was to investigate the effect of total pressure on the hardness distribution and plane strain modulus distribution along the distance from the cutting edge.

[0097] Use the following process parameters:

[0098] Temperature: 300℃

[0099] Average power: 40kW (20kW per target)

[0100] Pulse duration: 80μs

[0101] Peak current settings: Target 1: 800A, Target 2: 800A

[0102] DC pulse voltage: 1800V

[0103] Ar flow rate: 500sccm | 180sccm | 130sccm

[0104] Total pressure (N2 + Ar): 0.505 Pa | 0.219 Pa | 0.167 Pa

[0105] (~167sccm N2)|(~115sccm N2)|(~108sccm N2)

[0106] Bias potential: -100V

[0107] A (Ti,Al)N layer with a deposition thickness of approximately 1.75 μm was deposited. The average thickness of the (Ti,Al)N sublayer, calculated from the substrate rotation speed, was approximately 3 nm.

[0108] The coated cutting tools provided are referred to as “Sample 1” (0.505 Pa), “Sample 2” (0.219 Pa) and “Sample 3” (0.167 Pa).

[0109] Hardness measurements (load 15 mN) were performed on the cutting edge perpendicular to the flank face of the coated cutting tool, midway between the two tool tip radii, from the rake face to the flank face. Vickers hardness and plane strain modulus (E) were also determined. ps The value of ). Figure 5-6 The results are shown. It is evident that there is a relationship between total pressure and the high plane strain modulus and high hardness extension along a distance perpendicular to the cutting edge. Samples 2 and 3 are within the scope of this invention.

[0110] Example 2 (Effect of Temperature):

[0111] To investigate the effect of temperature on the hardness distribution and plane strain modulus distribution along the distance from the cutting edge, two additional samples were prepared. One sample was prepared using a Ti... 0.33 Al 0.67 The target and a component of Ti 0.20 Al 0.80 The target setup deposits a (Ti,Al)N layer onto a WC-Co matrix. The WC-Co matrix is ​​a square blade with a flat geometry for easier analysis of the coating. The matrix is ​​composed of 8 wt% Co and the balance WC.

[0112] The HIPIMS mode was used in the Hauzer Flexicoat 1000 apparatus. In two separate deposition processes, a total pressure of 0.219 Pa and temperatures of 350°C and 400°C were used, respectively. All other process parameters were the same as those used in Example 1.

[0113] A (Ti,Al)N layer with a deposition thickness of approximately 1.75 μm was deposited. The average thickness of the (Ti,Al)N sublayer, calculated from the substrate rotation speed, was approximately 3 nm.

[0114] The coated cutting tools provided are referred to as "Sample 4" and "Sample 5".

[0115] Now, hardness measurements (load 15 mN) are performed near the tool tip radius, perpendicular to the cutting edge line on the flank face of the coated cutting tools (Sample 2 deposited at 300°C, Sample 4 deposited at 350°C, and Sample 5 deposited at 400°C). In this case, the tool tip radius is 1 mm, and "near the tool tip radius" means that the hardness measurement is performed at the beginning of the tool tip radius. The plane strain modulus (E) is determined. ps ) and Vickers hardness values. Figure 7 and Figure 8 The results are shown.

[0116] It can be seen that the lowest temperature of 300°C gives a uniform level of Vickers hardness and plane strain modulus along a distance perpendicular to the cutting edge, while deposition at 350°C or 400°C gives a coating that shows a decrease in Vickers hardness and plane strain modulus values ​​as it moves away from the cutting edge.

[0117] Samples 2 and 4 are within the scope of this invention.

[0118] Other conclusions from Examples 1 and 2:

[0119] It should be noted that when comparing Sample 2 (Example 1) measured between the two blade tip radii and Sample 2 (Example 2) measured near the blade tip radius, it can be seen that for the same total pressure of 0.219 Pa, the near-blade radius, rather than along the distance from the midpoint between the two blade tip radii, provides a consistently high level of Vickers hardness and plane strain modulus along the distance from the cutting edge. This is because, in addition to the electric field concentration at the cutting edge, there is a corner effect at the blade tip radius in terms of local electric field concentration.

[0120] In metal cutting, the critical active region during cutting is located near the tool tip radius. Therefore, it is concluded that "Sample 2" and "Sample 3" are samples within the scope of this invention. "Sample 1" shows a sharp decrease in hardness and plane strain modulus as it moves away from the cutting edge, and even measurements taken midway between the two tool tip radii yield similar hardness and plane strain modulus distribution profiles near the tool tip radius. Therefore, "Sample 1" is considered outside the scope of this invention.

[0121] Example 3:

[0122] Another sample with a greater thickness (7.3 μm) corresponding to "Sample 2" (the invention) was prepared. The process parameters were:

[0123] Temperature: 300℃

[0124] Average power: 40kW (20kW per target)

[0125] Pulse duration: 80μs

[0126] Peak current settings: Target 1: 800A, Target 2: 800A

[0127] DC pulse voltage: 1800V

[0128] Ar flow rate: 180 sccm

[0129] Total pressure (N2 + Ar): 0.22 Pa

[0130] (~115sccm N2)

[0131] Bias potential: -110V

[0132] The coated cutting tool provided is referred to as "sample 2a".

[0133] Example 4:

[0134] Using a composition of Ti 0.20 Al 0.80 The target setup deposits a single monolayer, i.e., a (Ti,Al)N layer, onto a WC-Co matrix. The WC-Co matrix is ​​a flat geometry for easier analysis of the coating. The matrix is ​​composed of 8 wt% Co and the balance WC.

[0135] Using HIPIMS mode on the Hauzer Flexicoat 1000 device.

[0136] Use the following process parameters:

[0137] Temperature: 200℃

[0138] Average power: 20kW

[0139] Pulse duration: 80μs

[0140] Peak current setting: 800A

[0141] DC pulse voltage: 1800V

[0142] Ar flow rate: 150 sccm

[0143] Total pressure (N2 + Ar): 0.190 Pa

[0144] (~88sccm N2)

[0145] Bias potential: -150V

[0146] A (Ti,Al)N layer with a thickness of about 1.7 μm is deposited on the blade.

[0147] The coated cutting tool provided is referred to as "Sample 6 (Invention)".

[0148] Figure 9The image shows the plane strain modulus distribution of "Sample 6" measured on the flank face, along a direction perpendicular to the cutting edge, within a point 1 mm from the cutting edge. The plane strain modulus at a point 0.5 mm from the cutting edge is approximately 97% of the plane strain modulus at the cutting edge. The plane strain modulus at a point 1 mm from the cutting edge is approximately 87% of the plane strain modulus at the cutting edge. Figure 10 The image shows the hardness distribution of "Sample 6" measured on the flank face, along a direction perpendicular to the cutting edge, within a point 1 mm from the cutting edge. The hardness at the point 0.5 mm from the cutting edge is approximately 93% of the hardness at the cutting edge. The hardness at the point 1 mm from the cutting edge is approximately 73% of the hardness at the cutting edge.

[0149] Example 5 (Compared with Ti40Al60N, only the effect of bias is added):

[0150] Three types of coated cutting tool inserts were fabricated as references, with coatings of Ti, respectively. 0.40 Al 0.60 N-layer (“Sample 7”), Ti deposited under standard pressure and -40V bias 0.27 Al 0.73 N layer (“Sample 8”) and Ti deposited under standard pressure and -110V bias. 0.27 Al 0.73 N layers (“Sample 9”). The coating was deposited onto a WC-Co matrix using a flat blade (for easier analysis of the coating) in the HIPIMS mode on an Oerlikon Balzers instrument using S3p technology.

[0151] The matrix is ​​composed of 8% by weight Co and the balance WC.

[0152] The deposition process was performed in HIPIMS mode using the following process parameters.

[0153] Target material: Ti 0.40 Al 0.60 / / Ti 0.27 Al 0.73

[0154] Target size: 6 x circular, 15cm in diameter

[0155] Average power per target: 9kW

[0156] Peak pulse power: 55kW

[0157] Pulse duration: 4ms

[0158] Temperature: 430℃

[0159] Total pressure: 0.61 Pa

[0160] Argon pressure: 0.43 Pa

[0161] Bias potential: -40V (for Ti) 0.40 Al 0.60 The target sample and the use of Ti 0.27 Al 0.73 (Target sample)

[0162] Bias potential: -110V (for a device using Ti) 0.27 Al 0.73 (Target sample)

[0163] Each sample was deposited with a layer thickness of approximately 3 μm.

[0164] The coated cutting tools provided are referred to as "Sample 7", "Sample 8", and "Sample 9".

[0165] In addition, a sample corresponding to Sample 2 (Invention) was prepared. The HIPIMS mode was used in a Hauzer Flexicoat 1000 device.

[0166] The process parameters are:

[0167] Temperature: 300℃

[0168] Average power: 40kW (20kW per target)

[0169] Pulse duration: 80μs

[0170] Peak current settings: Target 1: 800A, Target 2: 800A

[0171] DC pulse voltage: 1800V

[0172] Ar flow rate: 180 sccm

[0173] Total pressure (N2 + Ar): 0.22 Pa

[0174] (~115sccm N2)

[0175] Bias potential: -110V

[0176] The deposited layer is approximately 3 μm thick.

[0177] The average thickness of the (Ti,Al)N sublayer, calculated from the matrix rotation speed, is approximately 3 nm.

[0178] The coated cutting tool provided is referred to as "Sample 10".

[0179] Figure 11The display shows the plane strain modulus distribution of "Sample 7", "Sample 8", "Sample 9" and "Sample 10" measured on the rake face, along the direction perpendicular to the cutting edge, within 1 mm from the cutting edge.

[0180] Figure 12 The display shows the plane strain modulus distribution of "Sample 7", "Sample 8", "Sample 9" and "Sample 10" measured on the back face of the cutting edge at a point 1 mm away from the cutting edge along a direction perpendicular to the cutting edge.

[0181] Figure 13 The display shows the hardness distribution of "Sample 7", "Sample 8", "Sample 9" and "Sample 10" measured on the rake face within 1 mm of the point at the cutting edge along a direction perpendicular to the cutting edge.

[0182] Figure 14 The display shows the hardness distribution of "Sample 7", "Sample 8", "Sample 9" and "Sample 10" measured on the back face of the cutting tool within 1 mm from the cutting edge along a direction perpendicular to the cutting edge.

[0183] Figures 11 to 14 Display the following content:

[0184] As expected, "low Al" Ti 0.40 Al 0.60 Layer N (“Sample 7”) exhibits a high plane strain modulus at a distance of at least 1 mm from the cutting edge. The Vickers hardness is also high at this distance.

[0185] Ti deposited under standard pressure and -40V bias voltage 0.27 Al 0.73 The N layer (“Sample 8”) exhibits very low plane strain modulus (≤250 GPa) at various distances from the cutting edge and at certain distances away from the cutting edge. The Vickers hardness is also very low (approximately 2000 HV). This indicates that the coating is almost entirely hexagonal, which was also confirmed by XRD analysis.

[0186] Ti deposited under standard pressure and -110V bias voltage 0.27 Al 0.73 Layer N (“Sample 9”) exhibits a high plane strain modulus (approximately 460 GPa) at the cutting edge. The Vickers hardness is also high at this distance (approximately 2800 HV). However, the hardness and plane strain modulus decrease at a certain distance away from the cutting edge. At a distance of 1 mm from the cutting edge, the Vickers hardness is only approximately 2300 HV, and the plane strain modulus is only approximately 320 GPa.

[0187] However, the conclusion is that simply increasing the bias voltage does indeed benefit Ti. 0.27 Al 0.73The N-layer provides a high hardness and high modulus structure, but only at the cutting edge, thus not providing any coating desired by the present invention.

[0188] However, the (Ti,Al)N layer (“Sample 10”) according to the invention exhibits a high level of plane strain modulus and hardness throughout the entire distance of 1 mm from the cutting edge.

[0189] Example 6:

[0190] Additional samples were prepared according to the present invention for use in metal cutting tests. 1.3 μm of conventional Ti was deposited via cathodic arc evaporation. 0.40 Al 0.60 The first N layer is provided on a WC-Co type substrate, followed by a 1.25 μm (Ti,Al)N layer very similar to the (Ti,Al)N layer of "Sample 2". The WC-Co type substrate has two different milling tool geometries, SPMW12 and ADMT160608R-F56. The composition of the substrate is 8 wt% Co and the balance WC. The main purpose of the innermost layer deposited by arc evaporation is to improve adhesion to the substrate so that tool life is not limited by spalling. The two layers are made as follows:

[0191] Ti 0.40 Al 0.60 Innermost layer N:

[0192] Using a composition of Ti 0.40 Al 0.60 The target will be 1.3μm Ti 0.40 Al 0.60 The N layer is deposited on a WC-Co matrix.

[0193] Arc mode was used in the Hauzer Flexicoat 1000 equipment. Deposition was performed at a total pressure of 5 Pa, a DC bias of -40 V, and a temperature of 580 °C.

[0194] (Ti,Al)N layer:

[0195] Using a composition of Ti 0.33 Al 0.67 The target and a component of Ti 0.20 Al 0.80 The target setup involves depositing a 1.25 μm (Ti,Al) N layer onto an arc-deposited Ti substrate. 0.40 Al 0.60 On layer N. Using HIPIMS mode on the Hauzer Flexicoat 1000 device.

[0196] Use the following process parameters:

[0197] Temperature: 300℃

[0198] Average power: 40kW (20kW per target)

[0199] Pulse duration: 80μs

[0200] Peak current settings: Target 1: 800A, Target 2: 800A

[0201] DC pulse voltage: 1800V

[0202] Ar flow rate: 180 sccm

[0203] Total pressure (N2 + Ar): 0.22 Pa

[0204] (~115sccm N2)

[0205] Bias potential: -100V

[0206] The average thickness of the (Ti,Al)N sublayer, calculated from the matrix rotation speed, is approximately 3 nm.

[0207] The resulting coated cutting tool is referred to as "Sample 11" (Invention).

[0208] Table 1 shows a summary of the samples produced.

[0209] Table 1

[0210]

[0211] Example 7 (Analysis):

[0212] XRD:

[0213] XRD analysis was performed on "Sample 1 (Comparison)", "Sample 2 (Invention)", "Sample 3 (Invention)" and "Sample 6 (Invention)".

[0214] All four samples showed peaks from the cubic (111), (200), and (220) planes. However, "Sample 1 (not included in this invention)" also showed significant peaks at approximately 57° and 70° 2θ, which were one or both of the hexagonal (110) (hexagonal AlN 57.29°), (112) (hexagonal AlN 68.85°), and (201) (hexagonal AlN 69.98°).

[0215] XRD analysis was also performed on "Sample 8 (Comparison)". A significant hexagonal peak was observed.

[0216] EBSD:

[0217] Electron backscatter diffraction (EBSD) analysis was performed on "Sample 2a (Invention)" and "Sample 6 (Invention)". The cumulative frequency distribution of the 111 orientation difference angle was calculated as described in the "Methods" section. Figure 15 The frequency distribution curve of the 111 orientation difference angle from the EBSD analysis of "Sample 2a (Invention)" is shown.

[0218] For “Sample 2a (Invention)”, the (Ti,Al)N layer shows a cumulative frequency distribution of 111 orientation difference angles, such that approximately 94% of the 111 orientation difference angles are less than 10 degrees.

[0219] Figure 16 The frequency distribution curve of the 111 orientation difference angle from the EBSD analysis of "Sample 6 (Invention)" is shown.

[0220] For “Sample 6 (Invention)”, the (Ti,Al)N layer shows a cumulative frequency distribution of 111 orientation difference angles, such that about 77% of the 111 orientation difference angles are less than 10 degrees.

[0221] TEM:

[0222] Transmission electron microscopy (TEM) analysis was performed on "Sample 2a" (the invention). The diffraction pattern of "Sample 2a" (the invention) is as follows: Figure 17 As shown, it exhibits distinct spots, indicating a high crystallographic texture. The diffraction pattern reveals 111 structured layers.

[0223] TEM analysis of “Sample 2a” (invention) showed that the average thickness of each (Ti,Al)N sublayer type was approximately the same, at about 3 nm.

[0224] EDX:

[0225] Energy-dispersive X-ray spectroscopy (EDX) analysis confirmed that the average composition of the (Ti,Al)N layer in "Sample 2a" (the invention) corresponds to the expected value of the target composition. The average composition is Ti. 0.27 Al 0.73 The total atomic ratio of the N layer (Ti,Al) to (Ti+Al) is 0.73.

[0226] Grain width:

[0227] The grain width of "Sample 2a" (invention) was measured. The grain widths at distances of 2, 4, and 6 μm from the lower interface of the matrix were measured.

[0228] The average grain widths were 127, 165, and 247 nm, respectively.

[0229] Example 7:

[0230] Cutting test, ISO-P milling:

[0231] The "Sample 11" (invention) was further tested in an ISO-P milling test, and the flank wear was measured. In this test, the "Sample 11" (invention) was compared with cutting inserts known to perform well in ISO-P milling.

[0232] The comparative coating tool is made by the following steps: providing a carbide substrate with a milling insert geometry of SPMW12, composed of 8 wt% Co and the balance WC, and depositing a coating according to the following conditions:

[0233] innermost Ti 0.40 Al 0.60 N layers:

[0234] Target material: Ti 0.40 Al 0.60

[0235] Target size: 6, round, 15cm in diameter

[0236] Average power per target: 9kW

[0237] Peak pulse power: 55kW

[0238] Pulse duration: 4ms

[0239] Temperature: 430℃

[0240] Total pressure: 0.61 Pa

[0241] Argon pressure: 0.43 Pa

[0242] Bias potential: -40V

[0243] A 2.1 μm layer was deposited.

[0244] Outermost ZrN layer:

[0245] Target material: Zr

[0246] Target size: 3, round, 15cm in diameter

[0247] Average power per target: 9kW

[0248] Peak pulse power: 27kW

[0249] Pulse duration: 26ms

[0250] Temperature: 430℃

[0251] Total pressure: 0.55 Pa

[0252] Argon pressure: 0.43 Pa

[0253] Bias potential: -40V

[0254] A 0.2 μm layer was deposited.

[0255] The comparison sample was a commercially produced sample. It contained a thin 0.2 μm ZrN layer deposited for color and easier wear detection purposes. However, this additional layer had no substantial impact on wear resistance.

[0256] The following is a summary of the test conditions and test data. Steel (ISO-P) was used as the workpiece material.

[0257] Test conditions:

[0258] Milling tests were conducted at a cutting speed of 240 m / min. Other test conditions were as follows:

[0259] Tool geometry:

[0260] Blade geometry: SPMW12

[0261] Tool diameter D c 125mm

[0262] Setting angle κ: 45°

[0263] Cutting data:

[0264] Contact width a e 100mm

[0265] Cutting depth a p 3mm

[0266] Cutting speed: 240 m / min

[0267] Feed per tooth: 0.2mm

[0268] Workpiece:

[0269] Material: ISO-P steel, 42CrMoV4 type

[0270] Tensile strength 785MPa

[0271] Cutting fluid: None, i.e., dry.

[0272] In this test, the maximum wear was observed at the cutting edge on the flank side. Three cutting edges were tested for each sample, and the average cutting lengths are shown in Table 2.

[0273] Table 2

[0274]

[0275] The comparative sample had a coating known to give very good results in milling ISO-P steel. Nevertheless, the conclusion is that "Sample 10" (the invention) performed much better than the comparative sample.

[0276] Example 8:

[0277] Cutting test, ISO-M milling:

[0278] The "Sample 11" (invention) was further tested in an ISO-M milling test, and the flank wear was measured. In this test, the "Sample 11" (invention) was compared with cutting inserts with arc-deposited coatings that are known to perform well in ISO-M milling.

[0279] The comparative coating tool is made by the following steps: providing a carbide substrate for milling inserts with a composition of 8 wt% Co and the balance WC, and depositing a coating according to the following conditions:

[0280] Innermost multilayer Ti 0.50 Al 0.50 N / Ti 0.33 Al 0.67 N layers:

[0281] Target material: 1 Ti 0.50 Al 0.50 / 1 Ti 0.33 Al 0.67

[0282] Temperature: 550℃

[0283] Total pressure: 10 Pa

[0284] Bias potential: -60V

[0285] A 1.3 μm layer was deposited.

[0286] Outermost layer Ti 0.50 Al 0.50 N / Ti 0.33 Al 0.67 N layers:

[0287] Target material: 1 Ti 0.50 Al 0.50 / 2 Ti 0.33 Al 0.67

[0288] Temperature: 550℃

[0289] Total pressure: 10 Pa

[0290] Bias potential: -50V

[0291] A 1.2 μm layer was deposited.

[0292] The test conditions and test data are summarized below. Stainless steel (ISO-M) was used as the workpiece material.

[0293] Test conditions:

[0294] Tool geometry:

[0295] Blade geometry: ADMT160608R-F56

[0296] Tool diameter D c 63mm

[0297] Setting angle κ: 90°

[0298] Number of teeth / installed blades: 3

[0299] Cutting data:

[0300] Contact width a e 50mm

[0301] Cutting depth a p 3mm

[0302] Cutting speed: 240 m / min

[0303] Feed per tooth: 0.15mm

[0304] Workpiece:

[0305] Material 1.4571 / V4A - Stainless Steel

[0306] Tensile strength 720MPa

[0307] Cutting fluid: None, i.e., dry.

[0308] In this test, the maximum wear was observed at the cutting edge on the flank side. Three cutting edges were tested for each coating, and the average cutting lengths are shown in Table 3.

[0309] Table 3.

[0310]

[0311] The comparative sample has a coating known to give very good results in milling stainless steel (ISO-M). Nevertheless, the conclusion is that "Sample 11" (the invention) performs much better than the comparative sample.

Claims

1. A coated cutting tool having at least one rake face and at least one flank face and a cutting edge therebetween, the coated cutting tool comprising a substrate and a coating, the coating comprising a (Ti,Al)N layer, the (Ti,Al)N layer being a single monolayer or a multilayer of two or more alternating (Ti,Al)N sublayers of different compositions, the total atomic ratio of the (Ti,Al)N layer being Al / (Ti+Al) > 0.67 but ≤ 0.

85. Its features The (Ti,Al)N layer exhibits a plane strain modulus distribution along a direction perpendicular to the cutting edge on the rake face and / or the flank face. The plane strain modulus at a point 0.5 mm away from the cutting edge is greater than 90% of the plane strain modulus at the cutting edge, and the plane strain modulus at the cutting edge is ≥450 GPa.

2. The coated cutting tool according to claim 1, wherein the plane strain modulus at a point 0.5 mm away from the cutting edge is greater than 95% of the plane strain modulus at the cutting edge.

3. The coated cutting tool according to any one of claims 1 to 2, wherein the (Ti,Al)N layer displays a plane strain modulus distribution along a direction perpendicular to the cutting edge on the rake face and / or the flank face, and the plane strain modulus at a point 1 mm away from the cutting edge is greater than 85% of the plane strain modulus at the cutting edge.

4. The coated cutting tool according to claim 3, wherein the plane strain modulus at a point 1 mm away from the cutting edge is greater than 90% of the plane strain modulus at the cutting edge.

5. The coated cutting tool according to any one of claims 1 to 2, wherein the (Ti,Al)N layer displays a hardness distribution along a direction perpendicular to the cutting edge on the rake face and / or the flank face, the hardness at a point 0.5 mm away from the cutting edge is greater than 70% of the hardness at the cutting edge, and the Vickers hardness at the cutting edge under a 15 mN load is ≥3000 HV.

6. The coated cutting tool according to claim 5, wherein the hardness at a point 0.5 mm away from the cutting edge is greater than 80% of the hardness at the cutting edge.

7. The coated cutting tool according to any one of claims 1 to 2, wherein the (Ti,Al)N layer exhibits a hardness distribution along a direction perpendicular to the cutting edge on the rake face and / or the flank face, the hardness at a point 1 mm away from the cutting edge is greater than 70% of the hardness at the cutting edge, and the Vickers hardness at the cutting edge under a 15 mN load is ≥3000 HV.

8. The coated cutting tool according to claim 7, wherein the hardness at a point 1 mm away from the cutting edge is greater than 80% of the hardness at the cutting edge.

9. The coated cutting tool according to any one of claims 1 to 2, wherein the plane strain modulus of the (Ti,Al)N layer at the cutting edge is ≥475 GPa.

10. The coated cutting tool according to any one of claims 1 to 2, wherein the (Ti,Al)N layer at the cutting edge has a Vickers hardness of 3500-4300 HV under a 15 mN load.

11. The coated cutting tool according to any one of claims 1 to 2, wherein the thickness of the (Ti,Al)N layer is 0.1 to 15 μm.

12. The coated cutting tool according to any one of claims 1 to 2, wherein the (Ti,Al)N layer exhibits a distribution of 111 orientation difference angles, the 111 orientation difference angle being the ratio of the normal vector of the surface of the (Ti,Al)N layer to the normal vector closest to the surface of the (Ti,Al)N layer. <111> The angle between directions The cumulative frequency distribution of the 111 orientation difference angles results in ≥60% of the 111 orientation difference angles being less than 10 degrees.

13. The coated cutting tool according to any one of claims 1 to 2, wherein the total atomic ratio Al / (Ti+Al) of the (Ti,Al)N layer is 0.70-0.

80.

14. The coated cutting tool according to any one of claims 1 to 2, wherein the (Ti,Al)N layer is a single monolayer.

15. The coated cutting tool according to any one of claims 1 to 2, wherein the (Ti,Al)N layer is a multilayer of two or more alternating (Ti,Al)N sublayer types that are different in composition, wherein the atomic ratio Al / (Ti+Al) of at least one (Ti,Al)N sublayer type is 0.50-0.67, and the atomic ratio Al / (Ti+Al) of at least one (Ti,Al)N sublayer type is 0.70-0.

90.

16. The coated cutting tool according to claim 15, wherein the average thickness of the (Ti,Al)N sublayer type in the multilayer is 1-100 nm.

17. The coated cutting tool according to any one of claims 1 to 2, wherein the (Ti,Al)N layer has a single-phase cubic B1 crystal structure at a point at least 1 mm away from the cutting edge on the rake face and / or the flank face along a direction perpendicular to the cutting edge.

18. The coated cutting tool according to any one of claims 1 to 2, wherein the substrate is selected from cemented carbide, cermet, cubic boron nitride, ceramic, polycrystalline diamond, and high-speed steel.

19. The coated cutting tool according to any one of claims 1 to 2, in the form of a cutting blade, a drill bit, or an end mill.

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