Multilayer coating for cutting tools and method for producing the same

Abstract

The application discloses a multilayer coating for a cutting tool and a preparation method thereof, the multilayer coating comprises a periodic multilayer coating deposited on a tool base body, and a cycle is "(AlCrVTiSi)N mixed layer to Ti 1‑z Si z N layer to (AlCrVTiSi)N mixed layer to Cr 1‑x‑ y Al x V y N / Cr 1‑m‑n Al m B n N nanometer multilayer", the nanometer multilayer comprises Cr 1‑x‑y Al x V y N nanometer layers and Cr 1‑m‑n Al m B n N nanometer layers alternately deposited, and the nanometer layers are coherently epitaxially grown. The preparation method comprises sequentially depositing a transition layer, the periodic multilayer coating, the (AlCrVTiSi)N mixed layer and the Ti 1‑a Si a N layer on the tool base body. The multilayer coating has the advantages of high wear resistance, high impact resistance and high heat resistance, and the preparation method has the advantages of simple process, conventional equipment and low production cost.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of metal cutting, and particularly relates to a multilayer coating for cutting tools and a preparation method thereof. BACKGROUND

[0002] PVD coating technology is increasingly widely used in the field of cutting tools, and gradually becomes one of the most important surface modification technologies for improving and enhancing the performance of cutting tools. Depositing a layer of PVD hard coating on the surface of a cutting tool can significantly improve the cutting performance of the tool and increase the machining efficiency. CrAlN coating is a metastable coating formed by replacing Cr in the CrN lattice with Al. The solid solution strengthening effect of Al atoms makes it have high hardness, and the oxidation resistance is also significantly improved due to the joint action of Al and Cr. Therefore, CrAlN coating is increasingly used in the field of cutting tools. However, the thermal stability of CrAlN coating is poor, and w-AlN softening phase will be precipitated at about 900℃, at the same time, Cr-N bond will be broken to form metastable h-Cr2N phase. With the further breaking of Cr-N bond, h-Cr2N continues to transform into its stable phase Cr, and this decomposition process will cause the hardness of CrAlN coating to continuously decrease. In the working condition with high cutting temperature, the relatively low thermal stability of CrAlN coating limits its application range.

[0003] TiSiN coating is one of the most concerned hard coating materials since 2000, which has a special nano-composite structure, i.e. the special structure of amorphous Si3N4 wrapping nano-sized TiN grains. The nano-sized TiN grains are wrapped by a thin layer of amorphous Si3N4, which not only hinders the migration of dislocations, but also inhibits the growth of grains under high temperature conditions. Therefore, this structure makes it have higher hardness and thermal stability. However, the residual stress of TiSiN coating is large, the surface quality of the coating is poor, the friction coefficient is large, and the film-substrate bonding strength is weak, which also limits the application range of TiSiN coating.

[0004] With the progress of modern machining technology and the deepening of the concept of green processing, high-speed dry cutting machining technology is increasingly becoming the mainstream technology. Moreover, with the development of material science, various new types of difficult-to-machine materials are increasing, which puts forward higher requirements on the performance of tool materials, especially the hard coating materials on the surface of tools. It is imperative to develop high-performance hard and wear-resistant coatings.

[0005] At present, in order to improve the thermal stability of CrAlN coating, the element Si is usually selected for alloying, however, Si alloying will cause the internal stress of CrAlSiN coating to increase significantly, resulting in the reduction of coating toughness, and Si alloying will reduce the solid solubility of Al atoms in the Cr-N lattice, causing the premature precipitation of w-AlN softening phase, reducing the wear resistance of the coating. Patent document CN104385751A discloses a composite multilayer coating cutter containing CrAlVN layer and CrAlSiN layer and its preparation method, which shows that by constructing a nano multilayer coating, the self-lubricating property and low friction coefficient of the CrAlVN layer can be utilized, and the high hardness and high thermal performance of the CrAlSiN layer can be utilized. The applicant's research shows that the CrAlVN / CrAlSiN nano multilayer coating still has insufficient wear resistance in actual cutting process, and the edge collapse phenomenon occurs, which may be related to the increase of internal stress caused by lattice distortion of CrAlSiN layer, and the examples in the above-mentioned document are all in the field of numerical control blades, and the application in rod-shaped cutters is not shown, and in actual application process, it will be found that there is a big difference between the machining conditions of numerical control blades and rod-shaped cutters.

[0006] Patent document CN108138305A discloses a stacked structure coating composed of AlCrN layer and nano multilayer alternating layer, wherein the nano multilayer alternating layer is formed by TiAlN and TiSiN alternately. The thickness of the AlCrN layer is 50-1000 nanometers, and the thickness of the TiAlN / TiSiN nano multilayer alternating layer is 50-1000 nanometers. Patent document CN101151397B shows that a tool coated with hard material sequentially has several different AlCrN (or AlCrCN) layers and TiSiN (or TiSiCN) layers, which can improve the machining performance of the drilling coating. Although the above-mentioned patent document optimizes the high residual stress of the TiSiN layer to a certain extent, it also causes the hardness of the coating to decrease, and the defect of poor thermal stability of the AlCrN layer is not fundamentally improved, so that it has insufficient wear resistance in actual application process.

[0007] Patent document CN102268637A discloses a nano multilayer coating cutter containing TiAlN and CrAlN, wherein the single layer thickness of the TiAlN layer and the CrAlN layer is about 2-60 nanometers. This method has certain advantages in soft steel machining, but when machining materials with slightly higher hardness, the wear resistance is significantly reduced, which may be related to the low hardness.

[0008] Through the research of literature, it can be found that multi-alloying and structure multilayer are effective ways to improve the performance of PVD hard and wear-resistant coating, and are also the frontiers of research in the field of cutting tool coating. How to improve the thermal stability and mechanical properties of CrAlN coating and how to optimize the residual stress of TiSiN coating are still the realities that technology practitioners must face. By combining CrAlN and TiSiN coatings to form a multilayer structure coating, the performance of the coating can be improved to some extent. However, the actual cutting application research shows that the existing coating still cannot meet the requirements of high heat resistance, high wear resistance and high impact resistance in actual cutting process, and there is still a lot of room for optimization. SUMMARY

[0009] The technical problem to be solved by the present application is to overcome the shortcomings of the prior art and provide a multilayer coating for cutting tools with high hardness, low friction coefficient, high heat resistance and high impact resistance and a preparation method thereof.

[0010] To solve the above technical problems, the present application adopts the following technical solutions.

[0011] A multilayer coating for cutting tools, comprising a periodic multilayer coating deposited on the tool substrate, the periodic multilayer coating being a multi-period coating with "(AlCrVTiSi)N mixed layer to Ti 1-z Si z N layer to (AlCrVTiSi)N mixed layer to Cr 1-x- y Al x V y N / Cr 1-m-n Al m B n N nanolayer" as a cycle period, the Cr 1-x-y Al x V y N / Cr 1-m- n Al m B n N nanolayer comprises alternately deposited Cr 1-x-y Al x V y N nanolayer and Cr 1-m-n Al m B n N nanolayer, the thickness ratio of Cr 1-x- y Al x V y N nanolayer and Cr 1-m-n Al m B n N nanolayer is greater than or equal to 1, and the thickness ratio of Cr 1-x-y Alx V y N nanolayers and Cr 1-m- n Al m B n coherently epitaxially grow between the N nanolayers and the Cr 1-x-y Al x V y N nanolayers, 25% < x < 75%, 1% < y < 15%, the Cr 1-m-n Al m B n coherently epitaxially grow between the N nanolayers and the Ti 1-z Si z N layers, 0.5% < z < 25%.

[0012] The multilayer coating for cutting tools as described above, preferably 3% < y < 10%, 5% < n < 12%.

[0013] The multilayer coating for cutting tools as described above, preferably the layer thickness of the (AlCrVTiSi)N mixed layer is 20 nm ± 5 nm, the Ti 1-z Si z N layer is 60 nm to 250 nm, the Cr 1-x-y Al x V y N / Cr 1-m-n Al m B n N nanolayers is 80 nm to 350 nm, the Cr 1-x-y Al x V y N nanolayers is 2 nm to 40 nm, the Cr 1-m- n Al m B n N nanolayers is 2 nm to 40 nm, the Cr 1-x-y Al x V y N / Cr 1-m-n Al m B n N nanolayers is 80 nm to 350 nm, the Ti 1-z Si z N layer is > 1.

[0014] The multilayer coating for cutting tools as described above, preferably the Ti 1-z Si z N layer is 80 nm to 200 nm, the Cr 1-x-y Al x Vy N / Cr 1-m-n Al m B n N nanolayer has a thickness of 100-300 nm, and the Cr 1-x-y Al x V y N nanolayer has a thickness of 3-15 nm, and the Cr 1-m-n Al m B n N nanolayer has a thickness of 3-15 nm.

[0015] The multilayer coating for cutting tools as described above, preferably, the Cr 1-x-y Al x V y N nanolayer has a face-centered cubic structure, and the Cr 1-m-n Al m B n N nanolayer has a face-centered cubic structure or a mixed structure of face-centered cubic and hexagonal close-packed.

[0016] The multilayer coating for cutting tools as described above, preferably, the Cr 1-x-y Al x V y N / Cr 1-m-n Al m B n N nanolayer is a cycle of "Cr 1-x-y Al x V y N nanolayer to Cr 1-m-n Al m B n N nanolayer", and the number of cycles is 10-60, and the Cr 1-x-y Al x V y N / Cr 1-m-n Al m B n N nanolayer has a coherent interface structure, and the Cr 1-m-n Al m B n N nanolayer is along the Cr 1-x- y Al x V y N nanolayer has a face-centered cubic lattice epitaxial growth, and externally presents a similar face-centered cubic structure to the Cr 1-x-y Al x V y N nanolayer.

[0017] The multilayer coating for cutting tools as described above, preferably, the (AlCrVTiSi)N mixed layer comprises Cr 1-x-y Al x V y N nanolayers and Ti 1-b Si b N layers, wherein 0.5%≤b≤25%, the number of periodic structures is 2-4, the interface structure of the Cr 1-x-y Al x V y N nanolayers to Ti 1-b Si b N layers is coherent interface.

[0018] The multilayer coating for cutting tools as described above, preferably, the periodic multilayer coating is called a periodic structure by "(AlCrVTiSi)N mixed layer-Ti 1-z Si z N layer-(AlCrVTiSi)N mixed layer-Cr 1-x-y Al x V y N / Cr 1-m-n Al m B n N nanolayer", the number of cycle periods of the periodic multilayer coating is 4-20.

[0019] The multilayer coating for cutting tools as described above, preferably, further comprises a transition layer deposited between the tool substrate and the periodic multilayer coating, the transition layer is Cr 1-x-y Al x V y N nanolayer or Cr 1-x-y Al x V y N / Cr 1-m-n Al m B n N nanolayer, the number of cycles is 25-80, the thickness of the transition layer is 200-400 nm.

[0020] The multilayer coating for cutting tools as described above, preferably, further comprises an outermost Ti 1-a Si a N layer deposited on the periodic multilayer coating, wherein 0.5%≤a≤25%, the thickness of the outermost Ti 1-a Si a N layer is 300-500 nm, and the (AlCrVTiSi)N mixed layer is further provided between the outermost layer and the periodic multilayer coating.

[0021] Preferably, the total thickness of the multilayer coating for cutting tools described above is 1 μm to 10 μm.

[0022] As a general technical concept, the present invention also provides a method for preparing the above-mentioned multilayer coating for cutting tools, comprising the following steps:

[0023] S1. Pre-treat the surface of the cutting tool substrate, including ultrasonic cleaning and ion etching.

[0024] S2. Deposit a transition layer on the pretreated tool substrate surface;

[0025] S3. Cr is deposited alternately on the transition layer. 1-x-y Al x V y N-layer and Ti 1-b Si b An N layer is formed, creating a (AlCrVTiSi)N mixed layer, followed by Ti deposition. 1-z Si z N layer, followed by deposition of (AlCrVTiSi)N mixed layer, followed by deposition of Cr 1-x-y Al x V y N / Cr 1-m-n Al m B n N-nanometer multilayer, with the "(AlCrVTiSi)N hybrid layer-Ti" 1-z Si z N-layer - (AlCrVTiSi)N mixed layer - Cr 1-x-y Al x V y N / Cr 1-m-n Al m B n "N-nanometer multilayer" is a cycle, and multiple cycles are repeated to obtain a periodic multilayer coating. During the deposition process, the deposition pressure is 1.0 Pa to 6.0 Pa, the deposition temperature is 450℃ to 550℃, and the bias voltage is -40V to -100V. The on or off of the CrAlV target, CrAlB target, and TiSi target need to be adjusted according to the change of composition. The current of CrAlV target is 150A to 200A, the current of CrAlB target is 150A to 200A, and the current of TiSi target is 135A to 180A.

[0026] S4. First, deposit a (AlCrVTiSi)N mixed layer on a periodic multilayer coating, then deposit Ti. 1-a Si a Layer N serves as the outermost layer, ultimately resulting in a multi-layer coating used for cutting tools.

[0027] The method for preparing the multilayer coating for cutting tools, preferably, in step S2, the transition layer is Cr 1-x-y Al x V y N / Cr 1-m-n Al m B n The deposition pressure is 1.0 Pa to 6.0 Pa, the deposition temperature is 450 ℃ to 550 ℃, the target current of the CrAlV target and the CrAlB target is 150 A to 200 A, and the bias voltage is -40 V to -100 V.

[0028] The method for preparing the multilayer coating for cutting tools, preferably, in step S2, the transition layer is Cr 1-x-y Al x V y The deposition pressure is 1.0 Pa to 6.0 Pa, the deposition temperature is 450 ℃ to 550 ℃, the target current of the CrAlV target is 150 A to 200 A, and the bias voltage is -40 V to -100 V.

[0029] The method for preparing the multilayer coating for cutting tools, preferably, in step S4, the outermost Ti 1-a Si a The deposition pressure is 1.0 Pa to 6.0 Pa, the deposition temperature is 450 ℃ to 550 ℃, the target current of the TiSi target is 135 A to 180 A, and the bias voltage is -40 V to -100 V.

[0030] In the technical solution of the application, it is found through experimental research that doping V in CrAlN to form CrAlVN helps to improve the thermal stability of the CrAlN coating, and CrAlVN generates V2O5 with a self-lubricating effect at high temperature, thereby reducing the friction and wear between the tool material and the machined material. However, too low V content will result in that the self-lubricating effect is not obvious, and the improvement of the thermal stability of the coating is also limited, and too high V content will reduce the oxidation resistance of the coating, therefore, the atomic percentage of V element should be between 1% and 15%, and more preferably between 3% and 10%; doping B in CrAlN to form CrAlBN can improve the thermal stability and oxidation resistance of the CrAlN coating at the same time, it is found in the research that the B content has an important influence on the performance of the CrAlBN coating, too low B content will not obviously improve the hardness of the CrAlBN coating, and too high B content will promote the precipitation of w-AlN, thereby sharply reducing the hardness of the coating, in addition, it is found in the experiment that the CrAlBN coating has high residual stress, which will limit the performance of the coating. Therefore, the atomic percentage of B element should be between 1% and 15%, and more preferably between 5% and 12%. In view of the characteristics and advantages of CrAlVN and CrAlBN respectively, by constructing a nano-multilayer structure and alternately depositing CrAlVN layers and CrAlBN layers, the prepared CrAlVN / CrAlBN nano-multilayer coating has high heat resistance, self-lubricating property, high wear resistance and low residual stress in the macroscopic view. It is found in the research process that the thickness of the CrAlVN layer and the CrAlBN layer is preferably between 2 and 40 nanometers, and more preferably between 3 and 15 nanometers, if the thickness is too thin, the interface layer presents mixed diffusion, thereby reducing the mechanical properties of the coating, and if the thickness is too thick, the interface is difficult to form a coherent interface, which will also reduce the mechanical properties of the coating.

[0031] It is found in the experimental research of the application that the TiSiN layer with a thickness of 60-250 nanometers, preferably 80-200 nanometers, is interposed between the CrAlVN / CrAlBN nano-multilayer, the thickness of the CrAlVN / CrAlBN nano-multilayer is between 80 and 350 nanometers, and preferably between 100 and 300 nanometers, and a (AlCrVTiSi)N mixed layer transition is formed by alternately depositing CrAlVN and TiSiN between the CrAlVN / CrAlBN nano-multilayer and the TiSiN layer, and the thickness of the layer transition is 20±5 nanometers, which can further improve the wear resistance, toughness, high-temperature performance and resistance to welding of the coating.

[0032] It is found in the experimental research of the application that the TiSiN layer with a thickness of 300-500 nanometers as the outermost layer can not only take advantage of its high hardness, but also avoid the disadvantage caused by high stress.

[0033] In the technical solutions of the present application, the cutting tool can be various cutting tools known in the art, such as a whole carbide milling cutter, a numerical control milling blade, a drill bit, and a numerical control turning blade, and the substrate can be carbide, metal ceramic, high-speed steel, or superhard material.

[0034] In the present application, Cr 1-x-y Al x V y When N is a face-centered cubic structure, the deposition process adopts a deposition method of preparing the coating crystal structure into a face-centered cubic structure, Cr 1-m-n Al m B n When N is a face-centered cubic structure or a mixed structure of face-centered cubic and hexagonal close-packed, the deposition process adopts a deposition method of preparing the coating crystal structure into a face-centered cubic structure or a mixed structure of face-centered cubic and hexagonal close-packed, and more preferably, Cr 1-m-n Al m B n N is a face-centered cubic structure.

[0035] Compared with the prior art, the present application has the following advantages:

[0036] 1. The CrAlVN / CrAlBN nanomultilayer in the cutting tool coating structure of the present application has self-lubricating property, resistance to cladding, and heat resistance during high-speed cutting, and the TiSiN layer exhibits excellent wear resistance and thermal stability during high-speed cutting.

[0037] In the cutting tool coating structure of the present application, the (AlCrVTiSi)N mixed layer with a laminated structure is introduced between the CrAlVN / CrAlBN nanomultilayer and the TiSiN layer, thereby strengthening the interfacial bonding strength therebetween.

[0038] The coherent interface in the CrAlVN / CrAlBN nanomultilayer and the mixed laminated interface between the CrAlVN / CrAlBN nanomultilayer and the TiSiN layer in the present application improve the stress distribution of the coating, which helps to inhibit the propagation of cracks during cutting and enhances the impact toughness of the coating.

[0039] 2. The cutting tool coating preparation method of the present application is simple, has low equipment requirements, and low production cost, and the coating tool prepared by the method can meet the demand of high-speed cutting, thereby improving the machining efficiency and service life of the cutting tool. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 FIG. 1 is a structure schematic diagram of the multilayer coating for a cutting tool according to Embodiment 1 of the present application.

[0041] Figure 2 FIG. 2 is a structure schematic diagram of the multilayer coating for a cutting tool according to Embodiment 2 of the present application.

[0042] Legend:

[0043] 11, Cr 1-x-y Al x V y N / Cr 1-m-n Al m B n N nanolayered transition layer; 12, Cr 1-x-y Al x V y N nanolayered transition layer; 2, Ti 1-z Si z N layer; 3, Cr 1-x-y Al x V y N / Cr 1-m-n Al m B n N nanolayered; 4, (AlCrVTiSi)N hybrid layer; 5, outermost Ti 1- a Si a N layer; 6, tool substrate. DETAILED DESCRIPTION

[0044] The application will be further described with reference to the drawings and specific preferred embodiments described below, but the scope of the application is not limited by the following examples. The materials and instruments used in the following examples are commercially available.

[0045] Example 1:

[0046] A multilayer coating for a cutting tool according to the application, as shown in Figure 1 Figure 1, comprises a periodic multilayer coating deposited on a tool substrate 6, the periodic multilayer coating being a multicycle coating with one cycle period of “N nanolayered transition layer 1 to (AlCrVTiSi)N hybrid layer 4 to Ti 1-z Si z N layer 2 to (AlCrVTiSi)N hybrid layer 4 to Cr 1-x-y Al x V y N / Cr 1-m-n Al m B n N nanolayered 3” comprises alternatingly deposited Cr 1-x-y Al x V y N / Cr 1-m-n Al m B n N nanolayered 3 includes alternatingly deposited Cr 1-x-y Al x V y N nanolayered with Cr 1-m- N nanolayered with Crn Al m B n N nanolayer, Cr 1-x-y Al x V y N nanolayer and Cr 1-m-n Al m B n N nanolayer, Cr 1-x-y Al x V y N nanolayer and Cr 1-m-n Al m B n N nanolayer, Cr 1-x-y Al x V y N nanolayer, Cr 0.35 Al 0.6 V 0.05 N nanolayer, Cr 1-m-n Al m B n N nanolayer, Cr 0.28 Al 0.6 B 0.12 N nanolayer, Ti 1-z Si z N, Ti 0.85 Si 0.15 N.

[0047] In this example, the (AlCrVTiSi)N mixed layer 4 has a layer thickness of 20 nm, Ti 1-z Si z N layer 2 has a layer thickness of 180 nm, Cr 1-x-y Al x V y N / Cr 1-m-n Al m B n N nanolayer, Cr 1-x-y Al x V y N nanolayer, Cr 1-m-n Al m B n N nanolayer, Cr 1-x-y Al x V y N / Cr 1-m-n Al m B n N nanolayer, Ti 1-z Si z N layer 2 has a layer thickness of 180 nm, Cr

[0048] In this embodiment, Cr 1-x-y Al x V y The N nanolayer has a face-centered cubic structure, and Cr 1-m-n Al m B n The N nanolayer is a hybrid structure of face-centered cubic and close-packed hexagonal.

[0049] In this embodiment, Cr 1-x-y Al x V y N / Cr 1-m-n Al m B n N-nano multilayer 3 is based on "Cr 1-x-y Al x V y N nanolayers to Cr 1-m-n Al m B n The "N nanolayer" represents one cycle, with a cycle number of 25. Cr 1-x-y Al x V y N / Cr 1-m-n Al m B n The N-nanometer multilayer 3-layer interface structure is a coherent interface, Cr 1-m-n Al m B n N nanolayers along Cr 1-x-y Al x V y Face-centered cubic lattice epitaxial growth of N nanolayers.

[0050] In this embodiment, the (AlCrVTiSi)N hybrid layer 4 includes alternating deposited Cr... 1-x-y Al x V y N nanolayers and Ti 1- b Si b N layers, Ti 1-b Si b Layer N is Ti 0.85 Si 0.15 N, with "Cr" 1-x-y Al x V y N nanolayers to Ti 1-b Si b "N layers" represents one cycle, with a cycle number of 2. Cr 1-x-y Al x V y N nanolayers to Ti 1-b Si b The interface structure of layer N is a coherent interface.

[0051] In this embodiment, the number of periods of the periodic multilayer coating is 6.

[0052] In this embodiment, a transition layer of (AlCrVTiSi)N is deposited between the tool substrate 6 and the periodic multilayer coating, and the thickness of the transition layer is 300 nm. 1-x-y Al x V y N / Cr 1-m-n Al m B n N nanolayer to Cr 1-x-y Al x V y N nanolayer to Cr 1-m-n Al m B n N nanolayer is one period, and the thickness of the transition layer is 300 nm.

[0053] In this embodiment, an outermost layer of Ti 1-a Si a N layer 5, Ti 1-a Si a N layer is Ti 0.85 Si 0.15 N, the outermost layer is Ti 1-a Si a N layer 5 is 400 nm. Between the outermost layer and the periodic multilayer coating, a (AlCrVTiSi)N mixed layer 4 is provided, and the thickness is 20 nm.

[0054] In this embodiment, the total thickness of the multilayer coating is 3.84 μm.

[0055] In this embodiment, the tool substrate 6 is a hard alloy drill bit with an inner cooling hole, and the model is GD series (GD05C-0560). The substrate is 10 wt.% Co, and the rest is WC. The shank diameter D is 6.0 mm, and the blade diameter D is 5.6 mm.

[0056] A method for preparing a multilayer coating for a cutting tool according to this embodiment, comprising the following steps:

[0057] (1) The hard alloy drill bit of the above model is subjected to ultrasonic cleaning (including inner cooling hole cleaning treatment), PVD coating furnace Ar ion etching and other surface pretreatments.

[0058] (2) Physical vapor deposition (PVD) was performed on the pretreated substrate surface. The deposition pressure was 3.0 Pa, the deposition temperature was 500 °C, the bias voltage was set to -40 V, and the target currents for Cr28Al60B12 and Cr35Al60V5 were set to 180 A and 200 A, respectively. The Cr28Al60B12 and Cr35Al60V5 targets were turned on, and CrAlVN and CrAlBN were deposited alternately to obtain 300 nm Cr 1-x-y Al x V y N / Cr 1-m-n Al m B n N-nanometer multilayer transition layer 11, Cr 1-x-y Al x V y N is Cr 0.35 Al 0.6 V 0.05 N, Cr 1-m-n Al m B n N is Cr 0.28 Al 0.6 B 0.12 N, Cr 1-x-y Al x V y N nanolayers and Cr 1-m-n Al m B n The thicknesses of the N nanolayers are 7 nm and 5 nm, respectively, and the Cr... 1-x-y Al x V y N nanolayers and Cr 1-m-n Al m B n The N nanolayers maintain a coherent interface structure.

[0059] (3) The deposition gas pressure is 3.0 Pa, the deposition temperature is 500℃, the bias voltage is set to -80V, the Cr28Al60B12 target is turned off, the Cr35Al60V5 target is kept on, the current is kept at 200A, the Ti85Si15 target is turned on, the Ti85Si15 target current is set to 160A, and Cr is deposited alternately. 1-x-y Al x V y N nanolayers and Ti 1-b Si b N layer, deposited 20 nm (AlCrVTiSi)N hybrid layer 4;

[0060] (4) The deposition pressure is 3.0 Pa, the deposition temperature is 500 °C, the bias voltage is set to -80 V, the Cr35Al60V5 target is closed, the Cr28Al60B12 target remains closed, and the Ti85Si15 target remains open. The Ti85Si15 target current is set to 160 A, and 180 nm of Ti is deposited 1-z Si z N layer 2, Ti 1-z Si z N layer 2 is Ti 0.85 Si 0.15 N layer.

[0061] (5) The Cr28Al60B12 target remains closed, the Cr35Al60V5 target is opened, and the Ti85Si15 target remains open. A 20 nm (AlCrVTiSi)N mixed layer 4 is deposited, and the current of each target material, the deposition pressure, and the bias voltage are the same as in step (3) above.

[0062] (6) The deposition pressure is 3.0 Pa, the deposition temperature is 500 °C, the bias voltage is -80 V, the Ti85Si15 target is closed, the Cr35Al60V5 target remains open, the current is 200 A, and simultaneously, the Cr28Al60B12 target is opened, the current is 180 A, and 300 nm of Cr 1-x-y Al x V y N / Cr 1-m-n Al m B n N nanolayer 3, Cr 1-x-y Al x V y N nanolayer and Cr 1-m-n Al m B n N nanolayer each has a thickness of 7 nm and 5 nm, respectively, Cr 1-x-y Al x V y N nanolayer and Cr 1-m-n Al m B n N nanolayer maintains a coherent interface structure between them.

[0063] (7) Repeat steps (3) to (6) 5 times;

[0064] (8) The Cr28Al60B12 target is closed, the Cr35Al60V5 target remains open, the current remains 200 A, the Ti85Si15 target is opened, the Ti85Si15 target current is set to 160 A, and a 20 nm (AlCrVTiSi)N mixed layer 4 is deposited. The deposition pressure is 3.0 Pa, the deposition temperature is 500 °C, and the bias voltage is set to -80 V;

[0065] (9) Close the Cr28Al60B12 target and the Cr35Al60V5 target, keep the Ti85Si15 target open, the current is 160 A, the deposition pressure is 3.0 Pa, the deposition temperature is 500 ℃, the bias voltage is -80 V, and 400 nm of Ti is deposited 1-a Si a N layer as the outermost layer, to obtain a multilayer coated cutting tool.

[0066] In this embodiment 1, the deposition atmosphere is N2 atmosphere, and in the following other embodiments, unless otherwise specified, they are the same as this embodiment.

[0067] The tool substrate and model of the control sample 1 are the same as embodiment 1, and Cr 0.30 Al 0.70 N coating is deposited by physical vapor deposition method, and the total thickness of the coating is 3.84 μm, which belongs to the currently widely used hard alloy coated cutting tool on the market.

[0068] The tool substrate and model of the control sample 2 are the same as embodiment 1, and Cr 0.30 Al 0.70 N / Ti 0.85 Si 0.15 N multilayer coating, a total of 6 cycles, the outermost layer is 400 nm of Ti 1-a Si a N layer, the total thickness of the coating is about 3.84 μm, and the deposition process is similar to that of embodiment 1, only the CrAlVN / CrAlBN nanomultilayer in embodiment 1 is changed to Cr 0.30 Al 0.70 N, the (AlCrVTiSi)N mixed layer is changed to (AlCrTiSi)N mixed layer.

[0069] The tool substrate and model of the control sample 3 are the same as embodiment 1, and Ti 0.40 Al 0.60 N coating is deposited by physical vapor deposition method, and the total thickness of the coating is about 3.84 μm.

[0070] The tool substrate and model of the control sample 4 are the same as embodiment 1, and Cr 0.30 Al 0.70 N-Ti 0.85 Si 0.15 N double-layer coating, the total thickness of the coating is about 3.84 μm, wherein the thickness of the Cr 0.30 Al 0.70 N layer is about 2.56 μm, and the thickness of the Ti 0.85 Si 0.15 N layer is about 1.28 μm.

[0071] Table 1. Comparison of drilling performance between the multi-layer coated cutting tool and the control sample in Example 1 of this invention.

[0072]

[0073]

[0074] As shown in Table 1, under the same tool substrate and model, and the same cutting conditions, the multi-layer coated tool of the present invention has excellent wear resistance. When drilling C70S6 (HRC 30) and 45# steel (HB 180), it is significantly improved compared with the coated tools of the prior art. The failure mode of the present invention is normal wear. Except for the embodiments of the present invention, the cutting edges of the other comparative examples all showed varying degrees of built-up edge and breakage, indicating that the present invention has excellent wear resistance and corrosion resistance when machining high-hardness tempered steel, medium-low hardness 45# steel, and ductile cast iron.

[0075] Example 2

[0076] A multilayer coating for cutting tools according to the present invention, such as Figure 2 As shown, this includes a periodic multilayer coating deposited on the tool substrate 6, wherein the periodic multilayer coating consists of a (AlCrVTiSi)N mixed layer 4 to Ti 1-z Si z N-layer 2 to (AlCrVTiSi)N mixed layer 4 to Cr 1-x-y Al x V y N / Cr 1-m-n Al m B n N-nanometer multilayer 3” is a multi-cycle coating with one cycle, Cr 1-x-y Al x V y N / Cr 1-m-n Al m B n N-nano multilayer 3 includes alternating deposits of Cr 1-x-y Al x V y N nanolayers and Cr 1-m- n Al m B n N nanolayers, Cr 1-x-y Al x V y N nanolayers and Cr 1-m-n Al m B n The thickness ratio of N nanolayers > 1, Cr 1-x-y Al x Vy N nanolayers and Cr 1-m-n Al m B n N nanolayers grow coherently epitaxially, Cr 1-x-y Al x V y N nanolayers are Cr 0.35 Al 0.60 V 0.05 N nanolayers, Cr 1-m-n Al m B n N nanolayers are Cr 0.30 Al 0.60 B 0.10 N nanolayers, Ti 1-z Si z N are Ti 0.80 Si 0.20 N.

[0077] In this example, the (AlCrVTiSi)N mixed layer 4 has a layer thickness of 20 nm, Ti 1-z Si z N layer 2 has a layer thickness of 100 nm, Cr 1-x-y Al x V y N / Cr 1-m-n Al m B n N nanolayer 3 has a layer thickness of 150 nm, Cr 1-x-y Al x V y N nanolayer has a single layer thickness of 6 nm, Cr 1-m-n Al m B n N nanolayer has a single layer thickness of 4 nm, Cr 1-x-y Al x V y N / Cr 1-m-n Al m B n N nanolayer 3 has a layer thickness / Ti 1-z Si z N layer 2 has a layer thickness > 1.

[0078] In this example, the Cr 1-x-y Al x V y N nanolayer is a face-centered cubic structure, Cr 1-m-n Al m B n N nanolayer is a face-centered cubic structure.

[0079] In this example, the Cr 1-x-y Al x Vy N / Cr 1-m-n Al m B n N nanolayer to Cr 1-x-y Al x V y N nanolayer to Cr 1-m-n Al m B n N nanolayer to Cr 1-x-y Al x V y N / Cr 1-m-n Al m B n N nanolayer to Cr 1-m-n Al m B n N nanolayer to Cr 1-x-y Al x V y N nanolayer to Cr 1-x-y Al x V y N nanolayer to Cr

[0080] In this embodiment, the (AlCrVTiSi)N mixed layer 4 comprises Cr 1-x-y Al x V y N nanolayer and Ti 1- b Si b N layer, the Ti 1-b Si b N layer is Ti 0.80 Si 0.20 N, and a cycle of "Cr 1-x-y Al x V y N nanolayer to Ti 1-b Si b N layer" is a cycle of 2, and the interface structure of the Cr 1-x-y Al x V y N nanolayer to Ti 1-b Si b N layer is a coherent interface.

[0081] In this embodiment, the number of cycles of the periodic multilayer coating is 10.

[0082] In this embodiment, a Cr 1-x-y Al x Vy N nanolayer transition layer 12, the transition layer being Cr 0.35 Al 0.60 V 0.05 N, the thickness of the transition layer being 200 nm.

[0083] In this embodiment, a Ti outermost layer is also deposited on the periodic multilayer coating 1-a Si a N layer 5, Ti 1-a Si a N layer being Ti 0.80 Si 0.20 N, outermost layer being Ti 1-a Si a N layer 5 has a thickness of 400 nm. A (AlCrVTiSi)N mixed layer 4 having a thickness of 20 nm is also provided between the outermost layer and the periodic multilayer coating.

[0084] In this embodiment, the total thickness of the multilayer coating is 3.52 μm.

[0085] In this embodiment, the tool substrate 6 is a square shoulder end mill of PM series (PM-4E-D6.0), the substrate being 12 wt.% Co and the rest being WC, the cutting edge diameter D = 6.0 mm.

[0086] A method for preparing a multilayer coating for a cutting tool according to this embodiment comprises the following steps:

[0087] (1) ultrasonic cleaning, PVD coating furnace Ar ion etching and other surface pretreatment of the above-mentioned type of cemented carbide end mill;

[0088] (2) treating the surface of the above-mentioned pretreated substrate by physical vapor deposition (PVD), the deposition pressure being 3.5 Pa, the deposition temperature being 450°C, the bias being -60 V, the Cr35Al60V5 target being turned on, the target material current being 180 A, a 200 nm CrAlVN transition layer being deposited, the CrAlVN layer being a face-centered cubic structure;

[0089] (3) the deposition pressure being 3.5 Pa, the deposition temperature being 450°C, the bias being -80 V, the Cr35Al60V5 target being kept on, the target material current being 180 A, the Ti80Si20 target being turned on, the target material current being 150 A, a (AlCrVTiSi)N mixed layer 4 being deposited, the mixed layer having a thickness of 20 nm;

[0090] (4) turning off the Cr35Al60V5 target, the deposition pressure being 3.5 Pa, the deposition temperature being 450°C, the bias being -80 V, the Ti80Si20 target being kept on, the target material current being 150 A, a 100 nm TiSiN layer being deposited;

[0091] (5) Open the Cr35Al60V5 target, the target current is 180 A, keep the Ti80Si20 target open, the target current is 150 A, the deposition pressure is 3.5 Pa, the deposition temperature is 450 °C, the bias voltage is -80 V, and 20 nm of (AlCrVTiSi)N mixed layer 4 is deposited;

[0092] (6) Close the Ti80Si20 target, keep the Cr35Al60V5 target open, the target current is 180 A, at the same time, open the Cr30Al60B10 target, the target current is set to 165 A, the deposition pressure is 3.5 Pa, the deposition temperature is 450 °C, the bias voltage is -80 V, and 150 nm of CrAlVN / CrAlBN nanolayer is deposited, the thickness of CrAlVN and CrAlBN layers is about 6 nm and 4 nm respectively, so as to keep the coherent interface structure between CrAlVN layer and CrAlBN layer;

[0093] (7) Repeat steps (3)-(6) 9 times;

[0094] (8) Close the Cr30Al60B10 target, keep the Cr35Al60V5 target open, the target current is 180 A, open the Ti80Si20 target, the target current is 150 A, and deposit (AlCrVTiSi)N mixed layer 4, the thickness of the mixed layer is 20 nm, the deposition pressure is 3.5 Pa, the deposition temperature is 450 °C, and the bias voltage is -80 V;

[0095] (9) Close the Cr30Al60B10 target and the Cr35Al60V5 target, keep the Ti80Si20 target open, the target current is 150 A, the deposition pressure is 3.5 Pa, the deposition temperature is 450 °C, the bias voltage is -80 V, and deposit 400 nm of TiSiN as the outermost layer to obtain a multilayer coated cutting tool.

[0096] The cutting tool substrate and model of the control sample 5 are the same as those of Example 2, and a Ti 0.40 Al 0.60 N coating is deposited by physical vapor deposition method, the coating thickness is 3.52 μm, and the cutting tool belongs to the currently widely used hard alloy coated cutting tool in the market.

[0097] The cutting tool substrate and model of the control sample 6 are the same as those of Example 2, and an Al 0.70 Cr 0.30 N coating is deposited by physical vapor deposition method, the coating thickness is 3.52 μm, and the cutting tool belongs to the currently widely used hard alloy coated cutting tool in the market.

[0098] The cutting tool substrate and model of the control sample 7 are the same as those of Example 2, and a Ti 0.40Al 0.60 N-TiSiN double-layer coating, the coating thickness is 3.52 μm, which belongs to the hard alloy coated cutting tool commonly used in the market at present, wherein, Ti 0.40 Al 0.60 N layer thickness is 1.52 μm, and the TiSiN layer thickness is 2.0 μm.

[0099] The cutting tool substrate and model of the control sample 8 are the same as those of example 2, and the Cr 0.35 Al 0.60 V 0.05 N / Cr 0.30 Al 0.60 Si 0.10 N nano-multilayer coating, the total coating thickness is 3.52 μm, the modulation period is 10 nm, and the Cr 0.35 Al 0.60 V 0.05 N layer and the Cr 0.30 Al 0.60 Si 0.10 N layer are coherently interfaced.

[0100] The cutting tool substrate and model of the control sample 9 are the same as those of example 2, and the Al 0.60 Cr 0.40 N and Ti 0.40 Al 0.60 N / Ti 0.85 Si 0.15 N nano-multilayer are used to form a periodic multilayer coating tool, the period number is 10, the Al 0.60 Cr 0.40 N layer thickness is 200 nm, the Ti 0.40 Al 0.60 N / Ti 0.85 Si 0.15 N nano-multilayer thickness is 150 nm, the Ti 0.40 Al 0.60 N and Ti 0.85 Si 0.15 N each thickness is about 7 nm and 5 nm respectively. The total coating thickness is about 3.52 μm.

[0101] The cutting tool substrate and model of the control sample 10 are the same as those of example 2, and the periodic multilayer coating tool is prepared by the deposition method basically the same as that of example 2, the total coating thickness is kept at 3.52 μm, and there is no (AlCrVTiSi)N mixed layer in the coating structure.

[0102] The tool base body and model of the control sample 11 are the same as those of Example 2, and the periodic multilayer coating tool is prepared according to the substantially same deposition method as that of Example 2, the total thickness of the coating is kept as 3.52 μm, the compositions of the CrAlV target and the CrAlB target are changed to Cr20Al60V20 and Cr10Al70B20, and other process parameters are completely the same.

[0103] Table 2 Milling comparison experiment effects of the multilayer coating tool of Example 2 of the application and the control samples

[0104]

[0105]

[0106] As shown in Table 2, under the condition that the tool base body and model are the same and the cutting conditions are the same, the multilayer coating tool of the application has excellent wear resistance, and the effects of the coating tool of the prior art are obviously improved when milling NAK80 (HRC 38) and SKD61 steel (HRC 50). The failure mode of the application is normal wear. Except for the example of the application, the cutting edges of the other control samples all have different degrees of adhesion of chips and collapse of the cutting edge, which indicates that the application has excellent wear resistance, adhesion resistance, impact toughness and high temperature resistance when high-speed dry machining die steel and high-hardness steel. Compared with Example 2, the control sample 10 does not meet the requirement of containing the (AlCrVTiSi)N mixed layer in the application, and the composition of the Cr20Al60V20 and Cr10Al70B20 target materials in the control sample 11 exceeds the requirement of the application, and the effects are obviously decreased.

[0107] Example 3

[0108] A multilayer coating for a cutting tool of the application, as shown in Figure 2 , includes a periodic multilayer coating deposited on a tool base body 6, and the periodic multilayer coating is a multi-period coating with one cycle period, which includes a Cr 1-z Si z N layer 2 to an (AlCrVTiSi)N mixed layer 4 to a Cr 1-x-y Al x V y N / Cr 1-m-n Al m B n N nanolayer 3, which includes alternately deposited Cr 1-x-y Al x V y N / Cr 1-m-n Al m B n N nanolayer 3 includes alternately deposited Cr 1-x-y Alx V y N nanolayers and Cr 1-m- n Al m B n N nanolayers, Cr 1-x-y Al x V y N nanolayers and Cr 1-m-n Al m B n N nanolayers with a thickness ratio > 1, Cr 1-x-y Al x V y N nanolayers and Cr 1-m-n Al m B n N nanolayers grow coherently epitaxially between each other, Cr 1-x-y Al x V y N nanolayers are Cr 0.35 Al 0.60 V 0.05 N nanolayers, Cr 1-m-n Al m B n N nanolayers are Cr 0.35 Al 0.60 B 0.05 N nanolayers, Ti 1-z Si z N, Ti 1-b Si b N and the outermost Ti 1-a Si a N layers are all Ti 0.80 Si 0.20 N.

[0109] In this example, the (AlCrVTiSi)N mixed layer 4 has a layer thickness of 20 nm, Ti 1-z Si z N layer 2 has a layer thickness of 90 nm, Cr 1-x-y Al x V y N / Cr 1-m-n Al m B n N nanolayer 3 has a layer thickness of 120 nm, Cr 1-x-y Al x V y N nanolayer has a single layer thickness of 5.2 nm, Cr 1-m-n Al m B n N nanolayer has a single layer thickness of 4 nm, Cr 1-x-y Al x V yN / Cr 1-m-n Al m B n N nanolayer 3 Ti 1-z Si z N layer 2 >1.

[0110] In this embodiment, Cr 1-x-y Al x V y N nanolayer is face-centered cubic structure, Cr 1-m-n Al m B n N nanolayer is face-centered cubic structure.

[0111] In this embodiment, Cr 1-x-y Al x V y N / Cr 1-m-n Al m B n N nanolayer 3 is a cycle of "Cr 1-x-y Al x V y N nanolayer to Cr 1-m-n Al m B n N nanolayer" as a cycle, the number of cycles is 13, Cr 1-x-y Al x V y N / Cr 1-m-n Al m B n N nanolayer 3 interface structure is coherent interface, Cr 1-m-n Al m B n N nanolayer along Cr 1-x-y Al x V y N nanolayer face-centered cubic lattice epitaxial growth, outside presents similar face-centered cubic structure with Cr 1-x-y Al x V y N nanolayer.

[0112] In this embodiment, the (AlCrVTiSi)N mixed layer 4 includes Cr 1-x-y Al x V y N nanolayer and Ti 1- b Si b N layer, Ti 1-b Si b N is Ti 0.80 Si 0.20 N, "Cr 1-x-y Alx V y N nanolayers to Ti 1-b Si b N layers" is one cycle, the number of cycles is 3, Cr 1-x-y Al x V y N nanolayers to Ti 1-b Si b The interface structure of the "N layers" is a coherent interface.

[0113] In this embodiment, the number of cycles of the periodic multilayer coating is 13.

[0114] In this embodiment, a Cr 1-x-y Al x V y N nanolayer transition layer 12, the transition layer is Cr 0.35 Al 0.60 V 0.05 N, the thickness of the transition layer is 200 nm.

[0115] In this embodiment, a Ti 1-a Si a N layer 5, Ti 1-a Si a N layer is Ti 0.80 Si 0.20 N, the outermost layer is Ti 1-a Si a N layer 5 is 430 nm. The outermost layer and the periodic multilayer coating also have a (AlCrVTiSi)N mixed layer 4 therebetween, with a thickness of 20 nm.

[0116] In this embodiment, the total thickness of the multilayer coating is 3.90 μm.

[0117] In this embodiment 3, the tool substrate 6 is a square shoulder end mill, model HM series (HM-2B-R3.0), the substrate is 9 wt.% Co, the rest is WC, the cutting edge diameter D = 6.0 mm.

[0118] A method for preparing a multilayer coating for a cutting tool according to this embodiment, comprising the following steps:

[0119] (1) The above-mentioned type of cemented carbide end mill is subjected to ultrasonic cleaning, PVD coating furnace Ar ion etching and other surface pretreatments;

[0120] (2) On the pretreated substrate surface, a CrAlVN transition layer of 200 nm is deposited by physical vapor deposition (PVD) at a deposition pressure of 4.0 Pa, a deposition temperature of 500°C, a bias voltage of -40 V, a Cr35Al60V5 target opened, a target current of 180 A, and a single-phase cubic structure of the CrAlVN layer;

[0121] (3) A (AlCrVTiSi)N mixed layer 4 of 20 nm in thickness is deposited at a deposition pressure of 4.0 Pa, a deposition temperature of 500°C, a bias voltage of -60 V, a Cr35Al60V5 target kept opened, a target current of 180 A, a Ti80Si20 target opened, and a target current of 140 A;

[0122] (4) A TiSiN layer of 90 nm is deposited at a deposition pressure of 4.0 Pa, a deposition temperature of 500°C, a bias voltage of -60 V, and a Ti80Si20 target kept opened and a target current of 140 A;

[0123] (5) A (AlCrVTiSi)N mixed layer 4 of 20 nm is deposited at a deposition pressure of 4.0 Pa, a deposition temperature of 500°C, a bias voltage of -60 V, a Cr35Al60V5 target opened and a target current of 180 A, and a Ti80Si20 target kept opened and a target current of 140 A;

[0124] (6) A CrAlVN / CrAlBN nanolayer of 120 nm is deposited at a deposition pressure of 4.0 Pa, a deposition temperature of 500°C, a bias voltage of -60 V, a Cr35Al60V5 target kept opened and a target current of 180 A, and a Cr35Al60B5 target opened and a target current of 150 A, wherein the thickness of the CrAlVN layer and the CrAlBN layer is about 5.2 nm and 4 nm respectively, and a coherent interface structure is maintained between the CrAlVN layer and the CrAlBN layer;

[0125] (7) Steps (3) to (6) are repeated 12 times;

[0126] (8) A (AlCrVTiSi)N mixed layer 4 of 20 nm in thickness is deposited at a deposition pressure of 4.0 Pa, a deposition temperature of 500°C, a bias voltage of -60 V, a Cr35Al60V5 target kept opened and a target current of 180 A, and a Ti80Si20 target opened and a target current of 140 A;

[0127] (9) The Cr35Al60B5 target and the Cr35Al60V5 target are closed, the Ti80Si20 target is kept open, the target current is 140 A, the deposition pressure is 4.0 Pa, the deposition temperature is 500 °C, the bias voltage is -60 V, and 430 nm of TiSiN is deposited as the outermost layer to obtain a multilayer coated cutting tool.

[0128] The tool substrate and model of the control sample 12 are the same as those of Example 3, and a Cr 0.35 Al 0.60 Si 0.05 N coating is deposited by the physical vapor deposition method, and the coating thickness is 3.9 μm. The tool belongs to the currently widely used cemented carbide coated cutting tool.

[0129] The tool substrate and model of the control sample 13 are the same as those of Example 2, and a Ti 0.50 Al 0.50 N-Ti 0.50 Al 0.40 Si 0.10 N double-layer coating is deposited by the physical vapor deposition method, and the coating thickness is 3.9 μm. The thickness of Ti 0.50 Al 0.50 N and Ti 0.50 Al 0.40 Si 0.10 N is about 1.4 μm and 2.5 μm, respectively. The tool belongs to the currently widely used cemented carbide coated cutting tool.

[0130] The tool substrate and model of the control sample 14 are the same as those of Example 3, and an Al 0.60 Cr 0.40 N and Ti 0.40 Al 0.60 N / Ti 0.80 Si 0.20 N nanometer multilayer is deposited by the physical vapor deposition method to form a periodic multilayer coated cutting tool, and the period number is 13. The thickness of the Al 0.60 Cr 0.40 N layer is 160 nm, the thickness of the Ti 0.40 Al 0.60 N / Ti 0.80 Si 0.20 N nanometer multilayer is 140 nm, and the thickness of Ti 0.40 Al 0.60 N and Ti 0.80 Si 0.20 N is about 6 nm and 4 nm, respectively. The total coating thickness is about 3.9 μm.

[0131] The tool base and model of the control sample 15 are the same as those of Example 3, and the periodic multilayer coating is prepared according to the similar deposition method of Example 3, the target composition, deposition pressure, bias voltage and deposition temperature are kept consistent, and the total thickness of the coating is 3.9 μm. The difference is that the current values of the Cr35Al60B5 target and the Cr35Al60V5 target are interchanged, that is, the current of the Cr35Al60B5 target is increased from 150 A to 180 A, and the current of the Cr35Al60V5 target is reduced from 180 A to 150 A, and the thicknesses of the CrAlVN layer and the CrAlBN layer in the CrAlVN / CrAlBN nanometer multilayer are about 3.5 nm and 5.5 nm, respectively.

[0132] Table 3 milling comparison test results of the multilayer coated tool of the application and the control sample of Example 3

[0133]

[0134]

[0135] As shown in Table 3, under the same tool base and model and cutting conditions, the multilayer coated tool of the application has excellent wear resistance, and the failure mode is normal wear. In addition to the example of the application, the cutting edges of the other control samples all have different degrees of edge collapse and boundary damage, indicating that the application has excellent wear resistance, impact toughness and high temperature resistance when milling high hardness steel under high speed water cooling and dry machining. Compared with Example 3, the control sample 15 does not meet the requirement of the application that the thickness ratio of the CrAlVN layer to the CrAlBN layer in the CrAlVN / CrAlBN nanometer multilayer should be ≥1, thereby reducing the mechanical properties of the coating. 1-x-y Al x V y N layer and the Cr 1-m-n Al m B n N layer should be ≥1, thereby reducing the mechanical properties of the coating.

[0136] The above merely describes preferred embodiments of the present application, and is not intended to limit the present application in any form. Although the present application has been disclosed with the preferred embodiments as above, it is not intended to limit the present application. Any person skilled in the art, without departing from the spirit and technical solutions of the present application, can make many possible changes and modifications to the technical solutions of the present application, or modify equivalent embodiments with equivalent changes. Therefore, any simple modification, equivalent replacement, equivalent change and modification made to the above embodiments according to the technical essence of the present application, without departing from the technical solutions of the present application, still belongs to the protection scope of the technical solutions of the present application.

Claims

1. A multi-layer coating for a cutting tool, characterized by, A multi-periodic coating comprising a periodic multi-layer coating deposited on a tool substrate, said periodic multi-layer coating being a multi-periodic coating with a "Cr 1-z Si z N layer to (AlCrVTiSi)N hybrid layer to Cr 1-x-y Al x V y N / Cr 1-m-n Al m B n N nanolayer" as one cycle, said Cr 1-x- y Al x V y N / Cr 1-m-n Al m B n N nanolayer comprises alternatingly deposited Cr 1-x-y Al x V y N nanolayer and Cr 1-m-n Al m B n N nanolayer, said Cr 1-x-y Al x V y N nanolayer and Cr 1-m-n Al m B n N nanolayer have a thickness ratio ≥ 1, said Cr 1-x-y Al x V y N nanolayer and Cr 1-m-n Al m B n N nanolayer grow coherently epitaxially, said Cr 1-x-y Al x V y N nanolayer, 25% ≤ x ≤ 75%, 1% ≤ y ≤ 15%, said Cr 1-m-n Al m B n N nanolayer, 25% ≤ m ≤ 75%, 1% ≤ n ≤ 15%, said Ti 1-z Si z N layer, 0.5% ≤ z ≤ 25%; The (AlCrVTiSi)N mixed layer includes Cr 1-x-y Al x V y N nanolayers and Ti 1-b Si b N layers, wherein 0.5%≤b≤25%, the number of the periodic structures is 2-4, the interface structure of the Cr 1-x-y Al x V y N nanolayers to Ti 1-b Si b N layers is a coherent interface.

2. The multi-layer coating for a cutting tool according to claim 1, characterized by 3%≤y≤10%, 5%≤n≤12%.

3. The multi-layer coating for a cutting tool of claim 1, wherein, The layer thickness of the (AlCrVTiSi)N mixed layer is 20 nm ± 5 nm, and the Ti 1-z Si z The layer thickness of the Cr 1-x-y Al x V y N / Cr 1-m- n Al m B n The layer thickness of the Cr 1-x-y Al x V y The single layer thickness of the Cr 1-m-n Al m B n The single layer thickness of the Cr 1-x-y Al x V y N / Cr 1-m-n Al m B n The layer thickness of the Cr 1-z Si z N layer is > 1.

4. The multi-layer coating for a cutting tool according to claim 3, characterized by Ti 1-z Si z The layer thickness of the N layer is 80-200 nm, the Cr 1-x-y Al x V y The layer thickness of the N / Cr 1-m-n Al m B n The layer thickness of the N nanolayer is 100-300 nm, the Cr 1-x-y Al x V y The single layer thickness of the N nanolayer is 3-15 nm, the Cr 1-m-n Al m B n The single layer thickness of the N nanolayer is 3-15 nm.

5. The multi-layer coating for a cutting tool of claim 1, wherein, The Cr 1-x-y Al x V y The N nanolayer is a face-centered cubic structure, the Cr 1-m-n Al m B n The N nanolayer is a face-centered cubic structure or a mixed structure of face-centered cubic and hexagonal close-packed.

6. The multi-layer coating for a cutting tool of claim 1, wherein, The Cr 1-x-y Al x V y N / Cr 1-m-n Al m B n N nanolayers are in a cycle of "Cr 1-x-y Al x V y N nanolayers to Cr 1-m-n Al m B n N nanolayers", the number of cycles is 10-60, the Cr 1-x-y Al x V y N / Cr 1-m-n Al m B n N nanolayer interface structure is coherent interface, the Cr 1-m- n Al m B n N nanolayer along the Cr 1-x-y Al x V y N nanolayer face-centered cubic lattice epitaxial growth, the outside presents similar face-centered cubic structure with Cr 1-x- y Al x V y N nanolayer.

7. The multi-layer coating for a cutting tool according to any one of claims 1 to 6, characterized in that, The number of cycle periods of the periodic multi-layer coating is 4-20.

8. The multi-layer coating for a cutting tool according to any one of claims 1 to 6, characterized in that, Also included is a transition layer deposited between the tool substrate and the periodic multilayer coating, the transition layer being Cr 1-x-y Al x V y N nanolayers or Cr 1-x-y Al x V y N / Cr 1-m-n Al m B n N nanolayers, the thickness of the transition layer being 200 nm to 400 nm.

9. The multi-layer coating for a cutting tool according to any one of claims 1 to 6, characterized in that, a top layer of Ti deposited on the periodic multilayer coating 1-a Si a a layer of (AlCrVTiSi)N, where 0.5%≤a≤25%, the top layer of Ti 1-a Si a the thickness of the layer of (AlCrVTiSi)N is 300-500 nm, and a mixed layer of (AlCrVTiSi)N is also provided between the top layer and the periodic multilayer coating.

10. The multi-layer coating for a cutting tool according to any one of claims 1 to 6, characterized in that, The total thickness of the multi-layer coating for the cutting tool is 1-10 μm.

11. A method of producing a multilayer coating for a cutting tool as defined in any one of claims 1 to 10, characterized by The method comprises the following steps: S1, pretreating the surface of the cutting tool substrate, the pretreatment comprising ultrasonic cleaning and ion etching; S2, depositing a transition layer on the surface of the pretreated cutting tool substrate; S3, alternately depositing Cr on the transition layer 1-x-y Al x V y N layer and Ti 1-b Si b N layer, forming an (AlCrVTiSi)N mixed layer, then depositing Ti 1-z Si z N layer, again depositing an (AlCrVTiSi)N mixed layer, then depositing Cr 1-x-y Al x V y N / Cr 1-m-n Al m B n N nanolayer, to form a cycle of the "(AlCrVTiSi)N mixed layer-Ti 1-z Si z N layer-(AlCrVTiSi)N mixed layer-Cr 1-x-y Al x V y N / Cr 1-m- n Al m B n N nanolayer", repeating the deposition of multiple cycles to obtain a periodic multilayer coating, during the deposition process, the deposition pressure is 1.0 Pa to 6.0 Pa, the deposition temperature is 450°C to 550°C, the bias voltage is -40V to -100V, the CrAlV target, CrAlB target, and TiSi target need to be turned on or off according to the change of the composition, the CrAlV target current is 150A to 200A, the CrAlB target current is 150A to 200A, and the TiSi target current is 135A to 180A. S4, depositing a (AlCrVTiSi)N mixed layer on a periodic multi-layer coating, then depositing Ti 1-a Si a N layer as the outermost layer, 0.5%≤a≤25%, ultimately obtaining a multi-layer coating for cutting tools.

12. The method of producing a multi-layer coating for a cutting tool according to claim 11, characterized in that, In step S2, the transition layer is Cr 1-x-y Al x V y N / Cr 1-m-n Al m B n N nanolayer, the deposition pressure is 1.0 Pa to 6.0 Pa, the deposition temperature is 450°C to 550°C, the target current of the CrAlV target and the CrAlB target is 150 A to 200 A, and the bias voltage is -40 V to -100 V.

13. The method of producing a multi-layer coating for a cutting tool according to claim 11, wherein In step S2, the transition layer is Cr 1-x-y Al x V y The N layer is deposited at a pressure of 1.0 Pa to 6.0 Pa, a temperature of 450°C to 550°C, a CrAlV target current of 150 A to 200 A, and a bias voltage of -40 V to -100 V.

14. The method of producing a multi-layer coating for a cutting tool according to any one of claims 11 to 13, characterized in that, In step S4, the outermost layer Ti 1-a Si a During deposition of the N layer, the deposition pressure is 1.0 Pa to 6.0 Pa, the deposition temperature is 450°C to 550°C, the TiSi target material current is 135 A to 180 A, and the bias voltage is -40 V to -100 V.

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