Coated tool parts and coating methods

Abstract

The present invention relates to a coated tool component (10) of a machining tool having a substrate (12) coated with a wear layer (22) and a bonding layer disposed between the substrate (12) and the wear layer (22). The wear layer (22) and the bonding layer (20) each have a plurality of sublayers (24) arranged one above the other. Each sublayer (24) includes a first individual ply (26), a second individual ply (28) and a third individual ply (30), with the three individual plies (26, 28, 30) in the plurality of sublayers (24) being arranged in a regular alternating fashion one above the other. The first individual ply (26) is made of Al x1 Me 1-x1 (N y1 C 1-y1 The second individual ply (28) includes Al x2 Me 1-x2 (N y2 C 1-y2 The third individual ply (30) includes Al x3 Me 1-x3-z3 S z3 (Ny3C 1-y3 ). The ply thickness of the third individual ply (30) included in the bonding layer (20) varies from sublayer (24) to sublayer (24), such that the ply thickness of the third individual ply (30) in a sublayer (24) disposed further down, closer to the substrate (12), is less than the ply thickness of the third individual ply (30) in a sublayer (24) disposed further up, further from the substrate (12). In contrast, the ply thickness of the third individual ply (30) included in the wear layer (22) is essentially constant from sublayer (24) to sublayer (24), or at least varies less significantly from sublayer (24) to sublayer (24) compared to the bonding layer (20).

Description

[Technical Field]

[0001] This invention relates to a covered tool component for a machining tool. The invention further relates to a method for covering a tool component for a machining tool. [Background technology]

[0002] Tool parts and machining tools may, for example, be tool parts and tools used in the metalworking industry, respectively. However, in principle, such tools can also be used for processing other materials, such as glass and plastics.

[0003] Machining tools include, for example, turning tools, milling tools, drilling tools, and power skiving tools. According to the present invention, the covered tool component is either a separate component, such as a cutting insert, or part of such a machining tool, which is part of the tool integrated with a tool holder or tool shaft.

[0004] According to the present invention, the coated tool parts are preferably made from cemented carbide, cermet, polycrystalline cubic boron nitride, polycrystalline diamond, cutting ceramic, or high-speed steel. Therefore, the above-mentioned materials function as substrates for coating.

[0005] Although the aforementioned materials already possess very good machinability, they have extremely high hardness, wear resistance, and fracture resistance. Therefore, to optimize machinability, tool components or the entire tool are increasingly being coated. Such coatings provide optimal protection for tool components or the tool itself when there are dynamic stresses due to high cutting speeds and insufficient cooling. Thus, with appropriate coatings, it is possible to significantly extend the service life of such tool components.

[0006] The prior art has already disclosed several different coatings. In this regard, Patent Documents 1 to 3 are merely referenced as examples. The three publications mentioned above disclose various AlCrSiN coatings. The coating known from Patent Document 2 is, for example, an arc-PVD coating. Such arc-PVD coatings have a high defect density, which often leads to premature material failure. In contrast, DC sputtered layers often have insufficient layer adhesion due to being too soft and / or having relatively low ionization.

[0007] Al-containing layers often have the problem of forming a hexagonal phase (hexagonal crystal structure) even at low Al content, which reduces the hardness and wear resistance of the coating. In contrast, a more desirable Al-containing coating would have a cubic crystal structure. However, the latter is almost impossible to achieve when the Al content is relatively high. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] European Patent No. 2310594 [Patent Document 2] European Patent No. 1422311 [Patent Document 3] European Patent No. 2336382 [Disclosure of the Invention] [Problems that the invention aims to solve]

[0009] Therefore, an object of the present invention is to provide a coating for tool parts of machining tools that has a relatively high Al content but still has a cubic crystal structure and thus has very high hardness and high wear resistance. [Means for solving the problem]

[0010] This object is achieved by the coated tool part according to claim 1, the tool part comprising a substrate coated with a wear layer and an adhesive layer arranged between the substrate and the wear layer, the wear layer and the adhesive layer each having a plurality of sub-layers arranged one above the other, each sub-layer comprising a first individual ply, a second individual ply, and a third individual ply, the three individual plies in the plurality of sub-layers being arranged regularly and alternately one above the other, the first individual ply being Al x1 Me 1-x1 (N y1 C 1-y1 ) and the second individual ply being Al x2 Me 1-x2 (N y2 C 1-y2 ) and the third individual ply being Al x3 Me 1-x3-z3 Si z3 (Ny3C 1-y3 ) with 0 ≦ x1 ≦ 0.55 and x1 < x2, x1 < x3 and 0 ≦ y1, y2, y3 ≦ 1, Me comprising at least one of the following elements: Sc, Y, La, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, the ply thickness of the third individual ply comprised in the adhesive layer varying from sub-layer to sub-layer, whereby the ply thickness of the third individual ply in a further sub-layer arranged lower and closer to the substrate is thinner than the ply thickness of the third individual ply in a further sub-layer arranged higher and further away from the substrate and the ply thickness of the third individual ply comprised in the wear layer is essentially constant from sub-layer to sub-layer or at least does not vary as much from sub-layer to sub-layer as compared to the adhesive layer.

[0011] This object consists of - providing a tool part functioning as a substrate, - coating the substrate with an adhesive layer, - coating the substrate coated with the adhesive layer with a wear layer and The coating of the substrate by the bonding layer and the coating of the substrate coated with the bonding layer each include the deposition of a plurality of sub-layers arranged one above the other, each sub-layer including a first individual ply, a second individual ply, and a third individual ply, the three individual plies within the plurality of sub-layers being regularly and alternately arranged one above the other, the first individual ply being Al x1 Me 1-x1 (N y1 C 1-y1 ) and the second individual ply being Al x2 Me 1-x2 (N y2 C 1-y2 ) and the third individual ply being Al x3 Me 1-x3-z3 Si z3 (Ny3C 1-y3 ) where 0 ≦ x1 ≦ 0.55 and x1 < x2, x1 < x3 and 0 ≦ y1, y2, y3 ≦ 1, Me including at least one of the following elements: Sc, Y, La, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, the ply thickness of the third individual ply included in the bonding layer varying from sub-layer to sub-layer, whereby the ply thickness of the third individual ply in the sub-layer arranged further down and closer to the substrate is thinner than the ply thickness of the third individual ply in the sub-layer arranged further up and further away from the substrate, and the ply thickness of the third individual ply included in the wear layer is essentially constant from sub-layer to sub-layer or at least does not vary as much from sub-layer to sub-layer as compared to the bonding layer, also achieved by the method according to claim 14.

[0012] Thus, the coating according to the invention comprises a bonding layer and a wear layer arranged above it. Each layer consists of a plurality of sub-layers, each sub-layer having at least three different individual plies, referred to in this context as "first individual ply", "second individual ply" and "third individual ply". In principle, each sub-layer may also have more than three individual plies.

[0013] The three individual plies mentioned in different sublayers have different material compositions (see below for details). The three individual plies mentioned in multiple sublayers are arranged in a regular, alternating pattern vertically in both the bonding layer and the wear layer. The order of the individual plies in the bonding layer may be the same as in the wear layer, but is not necessarily required. Furthermore, the nomenclature "first, second, and third individual plies" used in this context is intended simply to distinguish the three individual plies, rather than implying a required order.

[0014] For simplicity, if we refer to the first individual ply as "1", the second individual ply as "2", and the third individual ply as "3", then possible sequences in the bonding layer and / or wear layer include 123123123... or 213213213... or 321321321... or 123412341234..., in which case "4" represents one or more additional individual plies per sublayer.

[0015] The first individual ply is Al x1 Me 1-x1 (Ny1C 1-y1 The formula includes ) where 0 ≤ x1 ≤ 0.55 and 0 ≤ y1 ≤ 1, and Me contains at least one of the following elements: Sc, Y, La, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W. x1 may also be 0, which means that the first individual ply does not necessarily have to contain aluminum, but may contain "only" one of the above-mentioned metals Me. However, preferably the first individual ply contains both aluminum and one of these metals. However, Al is relatively less. Since y1 can vary between 0 and 1, the first individual ply may be a nitride, carbide, or carbonitride.

[0016] The situation is similar with respect to the composition of the second and third individual plies, and the second individual ply is Al x2 Me 1-x2It contains and, due to the fact that x1 is less than x2, necessarily has a higher Al content than the first individual ply. Since 0 ≤ y2 ≤ 1, the second individual ply may also contain nitrides, carbides, or carbonitrides.

[0017] Third Individual Ply Al x3 Me 1-x3-z3 Si z3 (Ny3C 1-y3 In this case, the material mixture also includes Si in addition to aluminum and further metals. This material mixture may also take the form of nitrides, carbides, or carbonitrides (0 ≤ y3 ≤ 1). The Al content of the third individual ply is greater than that of the first individual ply, but not necessarily greater than that of the second individual ply.

[0018] The molar ratios of the three individual plies specified herein are reported as absolute decimals, such that, for example, a molar ratio of 0.55 corresponds to a molar ratio at 55% atomic percent (55 at%).

[0019] The specified material composition of the three individual plies, and their alternating arrangement, offers various technical advantages. The first individual ply has a relatively low Al content (<55 at%). It may also have a composition that contains no Al at all. Combined with one or more of the aforementioned metallic Me, the material mixture contained in the first individual ply has a cubic crystal structure. Including cubic nitrides (e.g., CrN, TiN...) or cubic carbides (e.g., TiC, ZrC...) can produce cubic solid solutions with much higher hardness and wear resistance compared to pure aluminum nitride or aluminum carbide, which typically have a hexagonal crystal structure.

[0020] The same principle, including cubic nitrides or cubic carbides, is also applicable to the second individual ply. However, due to the higher Al content of the second individual ply, the material mixture present within it actually has a hexagonal structure. However, through the alternating arrangement of the aforementioned individual plies, the second individual ply is cubically "stabilized" by the first individual ply so that it eventually also has a cubic structure. Thus, the second individual ply also contributes favorably to higher hardness and higher wear resistance. The relatively high Al content of the second individual ply results not only in high hardness but also in high oxidation resistance.

[0021] The silicon nitride or silicon carbide contained in the third individual ply also increases the hardness of the coating. However, silicon nitride or silicon carbide also typically promotes the formation of a hexagonal structure. However, the cubic structure of the first individual ply similarly suppresses the hexagonal structure of the third individual ply. Therefore, the actual hexagonal structure of the third individual ply is also "cubically stabilized" by the first individual ply.

[0022] In summary, this means that the hexagonal phases that normally occur in the second and third individual plies due to the material composition are suppressed by the application of a low-Al first individual ply, which is positioned between them and contains cubic nitride or cubic carbide. Thus, the cubic structure of the first individual ply ultimately results in the cubic structure of the second and third individual plies as well. This has proven to be extremely advantageous.

[0023] A further feature of the coating according to the present invention is that the ply thickness of the third individual plies differs from sublayer to sublayer within the bonding layer. The ply thickness of the third individual plies preferably increases from bottom to top. However, the increase does not need to be exactly constant, and this can hardly be guaranteed in any case for processing-related reasons. Importantly, the ply thickness of the third individual plies tends to increase at least from bottom to top, meaning that the ply thickness of the third individual plies in at least one sublayer located further down and closer to the substrate is thinner than the ply thickness of the third individual plies in at least one sublayer located further up and further away from the substrate.

[0024] In the wear layer, the ply thickness of the third individual ply does not change significantly from that of the bonding layer. Preferably, the ply thickness of the third individual ply included in the wear layer is essentially constant (constant, although there are processing-related variations).

[0025] Therefore, there is no "clear" transition between the individual plies of the bonding layer and the individual plies of the wear layer. Instead, there is a kind of Si gradient rising from bottom to top within the bonding layer. As a result, the entire coating is Si-containing and therefore harder than an equivalent coating with a Si-free bonding layer.

[0026] The coating according to the present invention can be manufactured, in particular, by high-energy impulse magnetron sputtering (HiPIMS). Manufacturing by HiPIMS at very high pulse power produces a very high-density, low-defect layer.

[0027] This will achieve the above objective.

[0028] In the improved embodiment of the present invention, 0.55 ≤ x2 ≤ 0.7 and 0.4 ≤ x3 ≤ 0.7. In other words, the Al content of the second individual ply preferably varies between 0.55 and 0.7, and the Al content of the third individual ply preferably varies between 0.4 and 0.7. These Al content values ​​were found to be advantageous in tests conducted by the applicant.

[0029] In a particularly preferred improved form, the conditions are 0.3 ≤ x1 ≤ 0.55, 0.55 ≤ x2 ≤ 0.65, and 0.5 ≤ x3 ≤ 0.65.

[0030] In further improved forms, it is preferable that 0.01 ≤ z3 ≤ 0.15 is applicable to the third individual ply. Therefore, the Si content preferably varies between 1% and 15%.

[0031] It was found to be particularly advantageous to include Cr as the metal (Me) in the three individual plies. Particularly good test results were achieved by including chromium nitride in the three individual plies (Me=Cr, y1=1, y2=1, y3=1).

[0032] As already mentioned, it is preferable that the ply thickness of the third individual ply contained in the bonding layer increases monotonically from sublayer to sublayer as the distance from the substrate increases. This results in a "perfect" gradient progression of Si content in the bonding layer. However, due to manufacturing-related rotations of tool parts during coating, there may be variations in the thickness of the individual ply, and therefore, in practice, the increase can simply be described as "essentially constant" or at least "having an increasing tendency."

[0033] The ply thicknesses of the first, second, and third individual plies within the wear layer are preferably constant or at least essentially constant / similar. In a preferred improved embodiment, the ply thickness t of the first, second, and third individual plies included in the wear layer is wear The following are applicable to each of the following: 1nm≦t wear ≤200nm, preferably 1nm ≤t wear ≤30nm, more preferably 2nm ≤t wear ≤25nm.

[0034] In the depth direction in which the sublayers are arranged vertically, this results in more than three sublayers per micrometer, preferably more than 10 sublayers per micrometer, and more preferably more than 20 sublayers per micrometer, in the bonding layer and the abrasion layer, respectively.

[0035] The overall thickness of the bonding layer is preferably less than the thickness of the wear layer.

[0036] It will be apparent that the features described above and those described below can be used not only in the specified combinations but also in other combinations or individually without departing from the scope of the present invention. It will also be apparent that the aforementioned features and the features defined in the claims for covered tool parts are similarly or equivalently relevant to the methods according to the present invention. [Brief explanation of the drawing]

[0037] [Figure 1] This is a schematic diagram of a coated tool component according to one embodiment of the present invention. [Figure 2] This is a schematic diagram illustrating the layer structure of a coating according to one embodiment of the present invention. [Figure 3] This is a schematic diagram of a test setup for manufacturing a coating according to one embodiment of the present invention. [Figure 4] This figure shows the test results. [Figure 5] This is an optical microscope image of a crater-ground sample of a substrate coated with the coating according to the present invention. [Figure 6] This is an SEM image of a substrate coated with the coating according to the present invention. [Figure 7] This is the result of the XRD analysis. [Figure 8] This is a table showing experimental results for various coating types. [Modes for carrying out the invention]

[0038] Embodiments of the present invention are shown in the accompanying drawings and described in detail below.

[0039] Figure 1 shows a coated tool component in a purely schematic form. The entire coated tool component is shown by reference numeral 10.

[0040] The covered tool component 10 may be, for example, a cutting insert. In this embodiment, the covered tool component 10 includes a cemented carbide base material 12 whose upper surface is covered with a coating 14. Of course, it is also possible for the entire surface of the tool component 10 to be covered.

[0041] In this case, the coated surface may be, for example, the rake face 16 of a cutting insert that includes one or more cutting edges 18.

[0042] Figure 2 schematically shows the layer structure of the coating 14. The coating 14 is divided into a bonding layer 20 and an abrasion layer 22. The bonding layer 20 is directly bonded to the substrate 12. The abrasion layer 22 is applied to the upper surface of the bonding layer 20.

[0043] The bonding layer 20 and the wear layer 22 each have a plurality of sub-layers 24. In this case, each of these sub-layers 24 consists of three individual plies 26, 28, and 30. In other embodiments (not shown herein), each sub-layer 24 may have further individual plies.

[0044] Individual pristines 26, 28, and 30 are referred to in this context as the first individual ply 26, the second individual ply 28, and the third individual ply 30, each having a different material composition, while each of the first individual ply 26, each of the second individual ply 28, and each of the third individual ply 30 have the same material composition. The three individual pristines are arranged alternately in a vertical order, in which case the order 123123123... is selected.

[0045] The first individual plies 26 and second individual plies 28 within all sublayers 24 preferably have the same thickness. However, it is preferable that the ply thickness of the third individual plies 30 varies within the bonding layer 20 and is the same size or thickness (i.e., does not vary) within the sublayers 24 of the wear layer 22. In the bonding layer 20, the ply thickness of the third individual plies 30 tends to increase at least from bottom to top, i.e., as it progresses from the substrate 12 to the transition area of ​​the wear layer 22. It is particularly preferable that the ply thickness of the third individual plies 30 within the bonding layer 20 increases essentially constant from sublayer 24 to sublayer 24. "Essentially constant" increase means a constant increase with relatively small process-related variability.

[0046] The overall thickness of the coating 14 is preferably in the range of 1 to 10 μm. The thickness of the bonding layer 20 is preferably less than the thickness of the wear layer 22. More preferably, the bonding layer 20 accounts for 10 to 30% of the total thickness of the coating 14.

[0047] The first and second individual pristines 26 and 28 preferably have a ply thickness of 1 to 30 nm. The ply thickness of the third individual ply 30 varies within the bonding layer 20, as previously mentioned. This preferably increases uniformly within the bonding layer 20 from bottom to top, from sublayer 24 to sublayer 24.

[0048] The first individual ply 26 contains the following mixture of materials: Al x1 Me 1-x1 (N y1 C 1-y1 The second individual ply 28 contains the following mixture of substances: Al x2 Me 1-x2 (N y2 C 1-y2 ). The third individual ply 30 contains the following mixture of substances: Al x3 Me 1-x3-z3 Si z3 (Ny3C 1-y3)。The parameters x1, x2, x3, y1, y2, and y3 follow the conditions of 0 ≦ x1 ≦ 0.55, x1 < x2, x1 < x3, 0 ≦ y1 ≦ 1, 0 ≦ y2 ≦ 1, and 0 ≦ y3 ≦ 1. The metal Me contains at least one of the following elements: Sc, Y, La, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W.

[0049] As shown by the tests conducted by the applicant, when the Al content in the first individual ply 26 is low and cubic nitrides or cubic carbides (MeN or MeC) are added to the second and third individual plies 28, 30, a cubic structure can be obtained. By continuously increasing the Si content in the third individual ply 30 of the bonding layer 20, a bonding layer 20 with high hardness and optimal adhesion to the substrate 12 has already been achieved. In addition, as a result of this progressive increase in the Si ratio within the bonding layer 20, there is no abrupt transition between the bonding layer 20 and the wear layer 22.

[0050] Therefore, the first individual ply 26 disposed therebetween also has the effect that the second and third individual plies 28, 30, which would have had a hexagonal structure based on the material composition (high Al content in the second individual ply 28 and high Al content and additional Si content in the third individual ply 30), similarly have a cubic structure.

[0051] Experiments conducted by the applicant, varying the material composition of three individual plies 26, 28, and 30, demonstrated that the three-ply sublayer 24 proposed in this invention is clearly advantageous in terms of both hardness and wear resistance. Figure 8 summarizes some of these experimental results. For various layer structures of the sublayer 24, the material composition of each individual ply 26, 28, and 30 (referred to here as "ply 1," "ply 2," and "ply 3") is shown. In addition, the first column for each case shows the basic structure of the sublayer 24 (monolithic, two-ply, or three-ply). Furthermore, it is stated whether or not a hexagonal structure / phase is formed. In the last column, the evaluated individual layers are qualitatively evaluated, with 1 being very good, 2 being good, 3 being satisfactory, 4 being appropriate, 5 being inappropriate, and 6 being unsatisfactory. Unlike before, the molar ratios of the material compositions shown in Figure 8 are given as percentages in at% rather than in absolute decimal form. Nevertheless, these are again given below as absolute molar ratios in decimal form.

[0052] The favorable Al content for the first individual ply 26 was found to be, in particular, an Al content of 0 ≤ x1 ≤ 0.55. Furthermore, the preferred Al content for the second individual ply 28 was 0.55 ≤ x2 ≤ 0.65, and the preferred Al content for the third individual ply 30 was 0.5 ≤ x3 ≤ 0.65. A Si content of 0.01 ≤ x3 ≤ 0.15 was found to be desirable / favorable for the third individual ply 30. The following material compositions were found to be particularly favorable for the three individual plies 26, 28, and 30, and are reported as (material composition for the first individual ply 26, material composition for the second individual ply 28, and material composition for the third individual ply 30): (CrN, Al 0.58 Cr 0.42 N, Al 0.58 Cr 0.34 Si 0.08 N); (Al 0.48 Cr 0.52 N, Al 0.58 Cr 0.42 N, Al 0.58 Cr 0.34 Si 0.08 N), (TiN, Al 0.67 Ti 0.25 Sc 0.08, Al 0.58 Cr 0.34 Si 0.08 N), (Ti 0.82 Si 0.18 N, Al 0.59 Ti 0.41 N, Al 0.58 Cr 0.34 Si 0.08 N), (Al 0.49 Ti 0.51 N, Al 0.68 Ti 0.32 N, Al 0.59 Ti 0.33 Si 0.08 N).

[0053] Figure 8 shows only the experimental results for nitrides, but further results obtained by the applicant not shown herein have shown that various carbides having similar properties and molar ratios of Al and Me can also be used in an equivalent manner.

[0054] Figure 3 shows the material composition (Al 0.48 Cr 0.52 N, Al 0.58 Cr 0.42 N, Al 0.58 Cr 0.34 Si 0.08 A schematic representation of the experimental apparatus used to manufacture the Cr-based coating 14 having N) is shown. For this purpose, a PVD coating apparatus was used to assist sputtering by the HiPIMS method. In this case, the applicant used a CC800-HiPIMS manufactured by CemeCon AG. The coating apparatus used has six cathodes, four of which operate in HiPIMS mode and two in DC mode. The Si-free target used for depositing the first and second individual plies 26, 28 operates in HiPIMS mode (identified as "HP" in Figure 3). The Si-containing target used for depositing the third individual ply 30 operates in DC mode (identified as "DC" in Figure 3). Thus, this is a hybrid process overall.

[0055] For the coating process, the cleaned tool 10 and substrate 12 are loaded into the coating device. Depending on their diameter, they are charged with one, two, three, or four rotations to ensure that all functional surfaces are coated.

[0056] To prepare for the coating process, the coating apparatus generates a high vacuum in the chamber, and a radiant heater within it heats the tool to approximately 500°C. The tool surface is then cleaned with a subsequent plasma etching process. For this purpose, a pressure of 200-500 mPa is established within the coating space with the help of a rare gas to generate plasma. A negative voltage exceeding 100V accelerates the rare gas ions to the tool surface, where impurities are removed.

[0057] In the final step before coating, the target surface is cleaned by a short sputtering of the target. For this purpose, a pressure exceeding 1000 mPa is generated with the help of a noble gas, and the sputtering process is initiated by applying a negative voltage to the target. During this target cleaning operation, a closed shutter protects the tool from the application of the material.

[0058] Subsequently, the actual coating of the tool or tool part 10 or the substrate 12 can be carried out. For this purpose, with the aid of a rare gas, a pressure of 300 - 600 mPa is generated, and then reactive gas, nitrogen and / or acetylene are introduced until an overall pressure of 630 - 1000 mPa is present. To form a tight layer structure, instead of the maximum of four cathodes used operating at a continuous voltage, rather voltage pulses are supplied and thus operate in the so-called HiPIMS mode. These HiPIMS pulses have a length of 10 - 200 μs, preferably 20 - 100 μs, and are generated 1000 - 8000 times per second. By supplying a negative voltage of 40 V - 100 V to the tool, the generated metal ions are accelerated onto the tool. To initiate the sputtering process, a voltage is supplied very rapidly to a cathode having a silicon-free target, as a result of which an average power of 6000 W - 12000 W is present across the entire cathode. In contrast, the voltage across the silicon-containing target increases over a period of 10 - 20 minutes, whereby the average sputtering power of these targets increases gradually continuously, and thus the thickness of the third individual ply 30 of the bonding layer 20 increases and the described silicon gradient occurs. After this gradient has been deposited, all targets operate at a constant power. By rotating the tool during the coating process, a nanostructured coating 14 is produced.

[0059] After the coating process has ended, the chamber is cooled to less than 200 °C before being ventilated, as a result of which the now coated tool can be removed.

[0060] The material composition of the target shown in FIG. 3 corresponds to the material composition shown in the last row of the Cr-based material mixture in FIG. 8. The coating achieved thereby (Al 0.48 Cr 0.52 N, Al 0.58 Cr 0.42 N, Al 0.58 Cr 0.34 Si 0.08N) produced far better results, particularly as indicated by the evaluated service life of the coated tool parts. In FIG. 4, this is shown by the life evaluations of various coatings, comparing the coating method of the present invention (shown at the right end of FIG. 4), the hexagonal AlCrN coating, and the hexagonal AlCrSiN layer. As is clear from this comparison, the coating according to the present invention was able to achieve a service life twice as long as that of the coatings having a hexagonal AlCrN layer and a hexagonal AlCrSiN layer. FIGS. 5 and 6 show the AlCrSiN coating of the present invention in optical microscope images and SEM images. These show, in particular, the substrate 12 and the coating 14 adhering thereto. In FIG. 5, the sublayer 24 can be seen. Further, due to the crater grinding sample, the surface 32 of the coating 14 is clear.

[0061] XRD analysis carried out by the applicant (the results of which are shown in FIG. 7) also confirms the fact that the crystal structure of the coating 14 of the present invention does not result in a hexagonal phase but is merely a cubic phase. In further XRD analysis, a compressive stress of > 2.5 GPa was applied. The instrumented indentation test showed a hardness of > 33 GPa and a ratio of the indentation hardness HIT to the indentation elastic modulus EIT: HIT 3 / EIT 2 > 0.15 (usually exceeding 0.2).

[0062] Therefore, the results were excellent material properties of the coating 14 of the present invention.

Claims

1. A covered tool part (10) of a machining tool, The material has a base material (12) covered with an abrasion layer (22) and a bonding layer disposed between the base material (12) and the abrasion layer (22), The abrasion layer (22) and the bonding layer (20) each include a plurality of sub-layers (24) arranged vertically, Each sublayer (24) includes a first individual ply (26), a second individual ply (28), and a third individual ply (30), The three individual plies (26, 28, 30) of each sublayer (24) are arranged such that the second individual ply (28) is placed on top of the first individual ply (26), and the third individual ply (30) is placed on top of the second individual ply (28). The first individual ply (26) is Al x1 Me 1－x1 (N y1 C 1－y1 ) including, The second individual ply (28) is Al x2 Me 1－x2 (N y2 C 1－y2 ) including, The third individual ply (30) contains Al x3 Me 1－x3－z3 Si z3 (Ny 3 C 1－y3 ) and 0≦x1≦0.55, x1<x2, x1<x3, 0≦y1, y2, y3≦1, Me contains at least one of the following elements: Sc, Y, La, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W. The ply thickness of the third individual ply (30) contained in the bonding layer (20) varies from sub-layer (24) to sub-layer (24), and as a result, the ply thickness of the third individual ply (30) in the sub-layer (24) located further down and closer to the substrate (12) is thinner than the ply thickness of the third individual ply (30) in the sub-layer (24) located further up and further away from the substrate (12). A coated tool part (10) in which the ply thickness of the third individual ply (30) contained in the wear layer (22) is constant from sub-layer (24) to sub-layer (24).

2. Al included in the first individual ply (26) x1 Me 1－x1 (N y1 C 1－y1 ), Al included in the second individual ply (28) x2 Me 1－x2 (N y2 C 1－y2 ), and Al included in the third individual ply (30) x3 Me 1－x3－z3 Si z3 (Ny 3 C 1－y3 The coated tool part according to claim 1, wherein each of the elements has a cubic crystal structure.

3. A covered tool component according to claim 1, wherein 0.55 ≤ x2 ≤ 0.7 and 0.4 ≤ x3 ≤ 0.

7.

4. The coated tool component according to claim 1, wherein 0 ≤ x1 ≤ 0.55, 0.55 ≤ x2 ≤ 0.65, and 0.5 ≤ x3 ≤ 0.

65.

5. A coated tool component according to claim 1, wherein 0.01 ≤ z3 ≤ 0.

15.

6. The coated tool part according to claim 1, wherein Me contains Cr.

7. The covered tool component according to claim 1, wherein y1 = 1, y2 = 1, and y3 = 1.

8. The coated tool part according to claim 1, wherein the ply thickness of the third individual ply (30) included in the bonding layer (20) increases monotonically from sublayer (24) to sublayer (24) as the distance from the substrate (12) increases.

9. The ply thickness t of the first, second, and third individual plies (26, 28, 30) included in the wear layer (22) wear However, in each case, 1 nm ≤ t wear A coated tool component according to claim 1, subject to the condition ≤200 nm.

10. The coated tool part according to claim 1, wherein in the depth direction in which the sublayers (24) are arranged vertically, the bonding layer (20) and the wear layer (22) have more than three sublayers (24) per 1 μm arranged vertically.

11. The coated tool part according to claim 1, wherein the thickness of the bonding layer (20) is thinner than the thickness of the wear layer (22).

12. The coated tool part according to claim 1, wherein the base material (12) is made of at least one of cemented carbide, cermet, polycrystalline cubic boron nitride, polycrystalline diamond, cutting ceramic, and high-speed steel.

13. A tool for machining a workpiece, comprising a covered tool component (10) as described in any one of claims 1 to 12.

14. A method for covering tool parts of a machining tool, - A step of providing a tool component that functions as a base material (12), - The step of covering the substrate (12) with a bonding layer (20), - The step of covering the substrate (12) covered with the bonding layer (20) with an abrasion layer (22) Includes, The coating of the substrate (12) by the bonding layer (20), and the coating of the substrate (12) covered with the bonding layer (20), each include the deposition of a plurality of sub-layers (24) arranged vertically. Each sublayer (24) includes a first individual ply (26), a second individual ply (28), and a third individual ply (30), The three individual plies (26, 28, 30) of each sublayer (24) are arranged such that the second individual ply (28) is placed on top of the first individual ply (26), and the third individual ply (30) is placed on top of the second individual ply (28). The first individual ply (26) is Al x1 Me 1－x1 (N y1 C 1－y1 ) including, The second individual ply (28) is Al x2 Me 1－x2 (N y2 C 1－y2 ) including, The third individual ply (30) is Al x3 Me 1－x3－z3 Si z3 (Ny 3 C 1－y3 ) including, 0≦x1≦0.55, x1<x2, x1<x3, 0≦y1, y2, y3≦1, Me contains at least one of the following elements: Sc, Y, La, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W. The ply thickness of the third individual ply (30) contained in the bonding layer (20) varies from sub-layer (24) to sub-layer (24), and as a result, the ply thickness of the third individual ply (30) in the sub-layer (24) located further down and closer to the substrate (12) is thinner than the ply thickness of the third individual ply (30) in the sub-layer (24) located further up and further away from the substrate (12). A method wherein the ply thickness of the third individual ply (30) contained in the wear layer (22) is constant from sub-layer (24) to sub-layer (24).

Images