A multi-element nano-alternating composite coating cutter and a preparation method thereof

Abstract

This application belongs to the field of machining tool technology, specifically relating to a multi-component nano-alternating composite coated tool and its preparation method. The composite coated tool, from the inside out, comprises: a tool substrate, a CrB2 coating, an AlCrBN coating, and (Al... a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n The coating, the (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n The coating is made of (Al) a Cr b Si c B d ) e N f Sublayer and (Al) i Cr j Si k W l ) m N n The sublayers are periodically composed, specifically in the manner of: within one cycle, the (Al) layers are cyclically superimposed from the inside out. a Cr b Si c B d ) e N f Sublayer and the (Al) i Cr j Si k W l ) m N n Sublayers, forming (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l )m N n Composite structural unit, the (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n Composite structural units are periodically stacked to form the (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n The coating is applied, and the number of cycles is 6-8. This application uses a CrB2 coating that forms a strong metallurgical bond with the tool substrate as the base layer, and an AlCrBN coating as the transition layer. a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n As a functional layer, the coating has similar elements and structures among its layers, achieving excellent compatibility from interface to surface, and fundamentally solving the problems of weak bonding and stress concentration caused by sudden changes in performance.

Description

Technical Field

[0001] This application relates to the field of machining tool technology, specifically to a multi-element nano-alternating composite coated tool and its preparation method. Background Technology

[0002] Currently, cutting tools in high-end manufacturing face severe challenges from difficult-to-machine materials such as high-temperature alloys and hardened steel. Traditional coatings such as TiAlN are prone to oxidation and softening at high temperatures, have insufficient wear resistance, and exhibit weak adhesion to the substrate, easily leading to early spalling or plastic deformation failure. Existing technology discloses a three-layer heterogeneous structure design, with AlCrSiBN as the main functional layer, which improves the coating's high-temperature oxidation resistance and wear resistance to some extent. However, it has shortcomings: the cutting edge is prone to chipping when machining hardened steel; and the problem of small plastic deformation and concentrated cutting force at the cutting edge during cutting, leading to easy tool breakage, remains unresolved. Therefore, a cutting tool with excellent wear resistance, hardness, and film-substrate adhesion strength, while also possessing good oxidation resistance, is needed. Summary of the Invention

[0003] To address the aforementioned technical problems, this application provides a multi-element nano-alternating composite coated cutting tool, which, from the inside out, comprises: a tool substrate, a CrB2 coating, an AlCrBN coating, and (Al... a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n The coating, the (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n The coating is made of (Al) a Cr b Si c B d ) e N f Sublayer and (Al) i Cr j Si k Wl ) m N n The sublayers are periodically composed, specifically in the manner of: within one cycle, the (Al) layers are cyclically superimposed from the inside out. a Cr b Si c B d ) e N f Sublayer and the (Al) i Cr j Si k W l ) m N n Sublayers, forming (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n Composite structural unit, the (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n Composite structural units are periodically stacked to form the (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n The coating is applied, and the number of cycles is 6-8.

[0004] As a preferred embodiment of the multi-element nano-alternating composite coated cutting tool described in this application, the thickness of the CrB2 coating is 0.1-0.3 μm, the thickness of the AlCrBN coating is 0.1-0.5 μm, and the thickness of the (Al... a Cr b Si c B d )e N f / (Al i Cr j Si k W l ) m N n The coating thickness is 1.5-3.5 μm, and the (Al) a Cr b Si c B d ) e N f The thickness of the sublayer is 5-35 nm, and the (Al) i Cr j Si k W l ) m N n The single-layer thickness of the sublayer is 5-35 nm, and the CrB2 coating, the AlCrBN coating, and the (Al a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n The total thickness of the coating is 1.7-4.3 μm.

[0005] As a preferred embodiment of the multi-element nano-alternating composite coating tool described in this application, the CrB2 coating has an atomic percentage of 30-40 at.% for Cr and 60-70 at.% for B.

[0006] As a preferred embodiment of the multi-element nano-alternating composite coating tool described in this application, the (Al) a Cr b Si c B d ) e N f The ratio of a, b, c, d in the sublayer is (0.55-0.60):(0.30-0.40):(0-0.10):(0-0.10), where (Al) a Cr b Si c B d ) e N f The ratio of e to f in the sublayer is (0.9-1.1):1, where (Al) a Crb Si c B d ) e N f Sublayer contains amorphous BN x Phase, the amorphous BN x The atomic content of the phase does not exceed that of Al. a Cr b Si c B d ) e N f 10% of the total atomic content of the sublayer.

[0007] As a preferred embodiment of the multi-element nano-alternating composite coating tool described in this application, the (Al) i Cr j Si k W l ) m N n The ratio of i, j, k, l in the sublayer is (0.55-0.60):(0.30-0.40):(0-0.10):(0-0.10), where (Al) i Cr j Si k W l ) m N n The ratio of m to n in the sublayer is (0.9-1.1):1, where (Al) i Cr j Si k W l ) m N n The sublayer contains an amorphous Si3N4 phase, wherein the atomic content of the amorphous Si3N4 phase does not exceed that of the (Al) i Cr j Si k W l ) m N n 20% of the total atomic content of the sublayer.

[0008] As a preferred embodiment of the multi-element nano-alternating composite coating tool described in this application, the (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N nThe composite structural unit also includes: the (Al) a Cr b Si c B d ) e N f The atomic concentration of boron (B) in the sublayer decreases and then increases from the inside to the outside along the cyclic superposition direction. In particular, amorphous BN precipitates in regions where the B concentration is higher than 8 at.%. x Mutually.

[0009] As a preferred embodiment of the multi-element nano-alternating composite coating tool described in this application, the (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n The composite structural unit also includes: the (Al) i Cr j Si k W l ) m N n The atomic concentration of W element in the sublayer shows a trend of increasing from low to high and then decreasing from the inside to the outside along the cyclic superposition direction. Among them, the region with W element concentration higher than 8 at.% constitutes a high W concentration region, in which nanocrystalline nc-WN phase with an average grain size of 5-10 nm precipitates. The region with W element concentration lower than 6 at.% constitutes a low W concentration region, in which Si element is enriched and precipitates amorphous α-Si3N4 phase, and the grain boundaries of the nc-WN phase are wrapped by the amorphous α-Si3N4 phase.

[0010] As a preferred embodiment of the multi-element nano-alternating composite coated cutting tool described in this application, the nano-hardness of the composite coated cutting tool is ≥38GPa, the bonding strength between the tool substrate and the coating is ≥70N, the coefficient of friction of the composite coated cutting tool is ≤0.33, and the weight gain of the coating after holding at 900℃ for 30min is ≤4.56mg.

[0011] This application also provides a method for preparing a multi-element nano-alternating composite coated cutting tool. The method comprises the following steps:

[0012] S1. Obtain the initial tool, and perform pretreatment and etching on the initial tool to obtain the tool substrate;

[0013] S2. A CrB2 layer is deposited on the tool substrate to obtain a CrB2 layered tool; the CrB2 coating is deposited on the surface of the tool substrate.

[0014] S3. An AlCrBN layer is deposited on the CrB2 layer tool to obtain an AlCrBN layer tool, wherein the surface of the CrB2 layer tool is coated with the AlCrBN coating.

[0015] S4. Perform (Al) processing on the AlCrBN layer tool. a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n Layer deposition to obtain (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n Layered cutting tool, the surface of the AlCrBN layered cutting tool is deposited with Al(Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n coating;

[0016] S5, regarding the (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N nThe composite-coated tool is obtained by cooling the multilayer tool. The composite-coated tool, from the inside out, comprises: the tool substrate, the CrB2 coating, the AlCrBN coating, and the (Al... a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n coating.

[0017] As a preferred embodiment of the preparation method of the multi-element nano-alternating composite coated tool described in this application, the pretreatment method in step S1 specifically includes: cleaning the initial tool using ultrasonic cleaning, and drying the surface of the initial tool using nitrogen blowing or drying; clamping the dried initial tool on the rotating frame of the coating equipment to ensure uniform clamping and coating uniformity; placing the rotating frame in the vacuum chamber of the physical vapor deposition coating equipment, which is equipped with CrB2 target, AlCrB target, AlCrSiB target and AlCrSiW target;

[0018] The etching method is as follows: the vacuum chamber is evacuated to a vacuum and heated to 450-550°C, Ar gas is introduced at a flow rate of 100-150 sccm, and a negative bias voltage of -180V to -220V is applied to etch the surface of the initial tool for 15-30 minutes to obtain the tool substrate.

[0019] In step S2, the CrB2 layer is deposited in the following manner: the CrB2 coating is deposited on the tool substrate using magnetron sputtering. The process parameters are: temperature 550-650℃, negative bias voltage -80V to -120V, CrB2 target sputtering power 6000-12000W, working pressure 0.04-0.06mbar, and deposition time 5-25min.

[0020] In step S3, the AlCrBN layer is deposited in the following manner: an arc ion plating process is used to deposit the AlCrBN coating on the CrB2 layer tool, wherein an AlCrB target is used and N2 gas is introduced, and the process parameters are: temperature 450-550℃, negative bias voltage -40 to -80V, arc current 140-200A, duty cycle 60-70%; the pressure of the N2 is 0.03-0.05mbar, and the deposition time is 5-25min.

[0021] In step S4, the (Al)a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n The specific deposition method is as follows: Arc ion plating is used to deposit the AlCrBN layer onto the cutting tool. a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n The coating, the (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n The coating is composed of the (Al) a Cr b Si c B d ) e N f Sublayer and the (Al) i Cr j Si k W l ) m N n The sublayers are periodically composed, specifically in the manner of: within one cycle, the (Al) layers are cyclically superimposed from the inside out. a Cr b Si c B d ) e N f Sublayer and the (Al) i Cr j Si k W l ) m N n Sublayers, forming (Al) a Crb Si c B d ) e N f / (Al i Cr j Si k W l ) m N n Composite structural unit, the (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n Composite structural units are periodically stacked to form the (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n The coating process involves 6-8 cycles, during which AlCrSiB and AlCrSiW targets are alternately activated. The N2 pressure and target current are periodically adjusted to ensure the (Al...) coating... a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n The W and B elements in the coating exhibit periodic variations; in the high W concentration region, 5-10 nm nanocrystalline nc-WN phases are formed, while in the low W concentration region, Si elements are enriched to form amorphous α-Si3N4 phases that encapsulate the grain boundaries of the nc-WN phases. The process parameters are: temperature 450-550℃, N2 pressure periodically adjusted within the range of 0.02-0.05 mbar, negative bias voltage -60 to -100 V, duty cycle 60-70%, target current periodically adjusted within the range of 140-200 A; deposition time 40-280 min.

[0022] In step S5, the cooling method includes natural cooling or controlled cooling to room temperature.

[0023] The beneficial effects of this application are as follows:

[0024] This application proposes a method for preparing multi-component nano-alternating composite coating cutting tools. This method constructs a fully compatible material system based on "Cr-BN". The coating system consists of a CrB2 coating that forms a strong metallurgical bond with the tool substrate as the bottom layer, a gradually changing AlCrBN coating as the transition layer, and finally a top layer of (Al...)... a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n As a functional layer, the coating exhibits close elemental composition and similar structure among its layers, achieving excellent compatibility from interface to surface. This fundamentally solves the problems of weak adhesion and stress concentration caused by abrupt performance changes. Furthermore, its unique amorphous-encapsulated nanocrystalline structure provides the coating with high hardness. This effectively addresses the issues of severe oxidation wear, adhesive wear, and chipping of cutting tools during the machining of hardened steel. Specifically:

[0025] (1) During high-temperature cutting, the substrate and coating of this application exhibit good bonding strength, as do the coatings themselves. Specifically, the AlCrBN coating acts as a bridge, resulting in better bonding between the CrB2 coating structure and the AlCrBN coating structure, thus improving the bonding strength; the functional layer is (Al a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n The coating is made of nano-(Al) a Cr b Si c B d ) e N f Sublayers and nano (Al) i Cr j Si k W l ) m N nThe sublayers are periodically composed, specifically in the manner of: within one cycle, the (Al) layers are cyclically superimposed from the inside out. a Cr b Si c B d ) e N f Sublayer and the (Al) i Cr j Si k W l ) m N n Sublayers, forming (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n Composite structural unit, the (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n Composite structural units are periodically stacked to form the (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n The coating is applied in 6-8 cycles. During the deposition process, the AlCrSiB target is pre-opened to deposit (Al... a Cr b Si c B d ) e N f Sublayer, post-deposition (Al) i Cr j Si k W l ) m Nn Sublayer, (Al) a Cr b Si c B d ) e N f The sublayer is based on the AlCrBN coating, with the addition of Si element. The elements are similar and compatible. (Al) a Cr b Si c B d ) e N f Sublayer and (Al) i Cr j Si k W l ) m N n The sublayers have similar compositions and structures, and the elements diffuse between the coatings, resulting in a higher bonding strength.

[0026] (2) In this application, the B element in the multilayer composite coating can reduce the coefficient of friction of the coating, the Si, B and W elements can ensure that the coating has high hardness at high temperature, and the Al and Cr elements can form a dense alumina protective film at high temperature, so that the coating has high oxidation resistance.

[0027] (3) In terms of structural design, the nano-alternating functional layer, by introducing a massive number of coherent interfaces, can effectively passivate microcracks and hinder dislocation movement, while simultaneously improving the coating's hardness, toughness, and high-temperature creep resistance. This multi-scale composite structure ensures that the coating can resist abrasive wear and avoid brittle chipping under extreme cutting heat and mechanical loads, significantly extending tool life. In terms of process, a composite technology of high-power pulsed magnetron sputtering (HiPIMS) and arc ion plating (AIP) is adopted. HiPIMS provides a dense and robust substrate for the coating, while AIP ensures efficient deposition. Crucially, the current and pressure parameters are varied in a "wave-like" manner during the functional layer deposition process. This is a dynamic ion bombardment and stress relaxation cycle that can actively interrupt columnar crystal growth, refine grains, and reduce internal stress, thereby synergistically optimizing the overall mechanical properties of the coating in a process-oriented manner.

[0028] In summary, the coated cutting tool prepared in this application possesses exceptional bonding strength, high-temperature stability, high hardness, and high toughness, effectively solving the problems of wear and plastic deformation in high-end cutting. This design concept is advanced, and all processes can be stably implemented on industrial physical vapor deposition (PVD) equipment, making it easy to promote and possessing enormous market application potential. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the cross-sectional structure of a multi-element nano-alternating composite coated cutting tool according to this application.

[0031] Reference numerals: 100, tool substrate; 200, CrB2 coating; 300, AlCrBN coating; 400, (Al a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n Coating; 411, (Al) a Cr b Si c B d ) e N f Sublayer; 412, (Al) i Cr j Si k W l ) m N n Sublayer; 410, (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n Composite structural unit.

[0032] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0033] The technical solutions in the embodiments will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0034] Please see Figure 1 This application provides a multi-element nano-alternating composite coated cutting tool, which, from the inside out, comprises: a cutting tool substrate 100, a CrB2 coating 200, an AlCrBN coating 300, and (Al... a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n Coating 400,

[0035] The (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n Coating 400 is made of (Al) a Cr b Si c B d ) e N f Sublayer 411 and (Al) i Cr j Si k W l ) m N n Sublayer 412 is periodically composed, and the periodic composition is specifically as follows: within one cycle, the (Al) is cyclically superimposed from the inside out. a Cr b Si c B d ) e N f Sublayer 411 and the (Al) i Cr j Si k W l) m N n Sublayer 412, forming (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n Composite structural unit 410, wherein (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n Composite structural units 410 are periodically stacked to form the (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n The coating is 400, and the number of cycles is 6-8.

[0036] The thickness of the CrB2 coating is 0.1-0.3 μm, and the thickness of the AlCrBN coating is 0.1-0.5 μm. a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n The coating thickness is 1.5-3.5 μm, and the (Al) a Cr b Si c B d ) e N f The thickness of the sublayer is 5-35 nm, and the (Al)i Cr j Si k W l ) m N n The single-layer thickness of the sublayer is 5-35 nm, and the CrB2 coating, the AlCrBN coating, and the (Al a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n The total thickness of the coating is 1.7-4.3 μm;

[0037] In the CrB2 coating, the atomic percentage of Cr is 30-40 at.% and the atomic percentage of B is 60-70 at.%.

[0038] The (Al) a Cr b Si c B d ) e N f The ratio of a, b, c, d in the sublayer is (0.55-0.60):(0.30-0.40):(0-0.10):(0-0.10), where (Al) a Cr b Si c B d ) e N f The ratio of e to f in the sublayer is (0.9-1.1):1, where (Al) a Cr b Si c B d ) e N f Sublayer contains amorphous BN x Phase, the amorphous BN x The atomic content of the phase does not exceed that of Al. a Cr b Si c B d ) e N f 10% of the total atomic content of the sublayer;

[0039] The (Al) i Cr j Si k Wl ) m N n The ratio of i, j, k, l in the sublayer is (0.55-0.60):(0.30-0.40):(0-0.10):(0-0.10), where (Al) i Cr j Si k W l ) m N n The ratio of m to n in the sublayer is (0.9-1.1):1, where (Al) i Cr j Si k W l ) m N n The sublayer contains an amorphous Si3N4 phase, wherein the atomic content of the amorphous Si3N4 phase does not exceed that of the (Al) i Cr j Si k W l ) m N n 20% of the total atomic content of the sublayer;

[0040] The (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n The composite structural unit also includes: the (Al) a Cr b Si c B d ) e N f The atomic concentration of boron (B) in the sublayer decreases and then increases from the inside to the outside along the cyclic superposition direction. In particular, amorphous BN precipitates in regions where the B concentration is higher than 8 at.%. x Mutually;

[0041] The (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m Nn The composite structural unit also includes: the (Al) i Cr j Si k W l ) m N n The atomic concentration of W in the sublayer shows a trend of increasing from low to high and then decreasing from the inside to the outside along the cyclic stacking direction. Among them, the region with a W concentration higher than 8 at.% constitutes a high W concentration region, in which nanocrystalline nc-WN phase with an average grain size of 5-10 nm precipitates. The region with a W concentration lower than 6 at.% constitutes a low W concentration region, in which Si is enriched and precipitates an amorphous α-Si3N4 phase, and the grain boundaries of the nc-WN phase are wrapped by the amorphous α-Si3N4 phase.

[0042] The composite coated tool has a nano-hardness ≥38GPa, a bonding strength between the tool substrate and the coating ≥70N, a friction coefficient ≤0.33, and a coating weight gain ≤4.56mg after holding at 900℃ for 30min.

[0043] This application also provides a method for preparing a multi-element nano-alternating composite coated cutting tool. The method comprises the following steps:

[0044] S1. Obtain the initial tool, and perform pretreatment and etching on the initial tool to obtain the tool substrate;

[0045] The pretreatment method specifically involves: cleaning the initial tool using ultrasonic cleaning, and drying the surface of the initial tool using nitrogen blowing or drying; clamping the dried initial tool onto the rotating frame of the coating equipment, ensuring uniform clamping to guarantee coating uniformity; placing the rotating frame in the vacuum chamber of the physical vapor deposition coating equipment, which is equipped with CrB2 target, AlCrB target, AlCrSiB target, and AlCrSiW target.

[0046] The etching method is as follows: the vacuum chamber is evacuated to a vacuum and heated to 450-550°C, Ar gas is introduced at a flow rate of 100-150 sccm, and a negative bias voltage of -180V to -220V is applied to etch the surface of the initial tool for 15-30 minutes to obtain the tool substrate.

[0047] S2. A CrB2 layer is deposited on the tool substrate to obtain a CrB2 layered tool; the CrB2 coating is deposited on the surface of the tool substrate.

[0048] The CrB2 layer deposition method is as follows: the CrB2 coating is deposited on the tool substrate using magnetron sputtering. The process parameters are: temperature of 550-650℃, negative bias voltage of -80V to -120V, CrB2 target sputtering power of 6000-12000W, working pressure of 0.04-0.06mbar, and deposition time of 5-25min.

[0049] S3. An AlCrBN layer is deposited on the CrB2 layer tool to obtain an AlCrBN layer tool, wherein the surface of the CrB2 layer tool is coated with the AlCrBN coating.

[0050] The AlCrBN layer deposition method is as follows: the AlCrBN coating is deposited on the CrB2 layer tool using an arc ion plating process, wherein an AlCrB target is used and N2 gas is introduced, and the process parameters are: temperature 450-550℃, negative bias voltage -40 to -80V, arc current 140-200A, duty cycle 60-70%; the pressure of the N2 is 0.03-0.05mbar, and the deposition time is 5-25min.

[0051] S4. Perform (Al) processing on the AlCrBN layer tool. a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n Layer deposition to obtain (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n Layered cutting tool, the surface of the AlCrBN layered cutting tool is deposited with Al(Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m Nn coating;

[0052] The (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n The specific deposition method is as follows: Arc ion plating is used to deposit the AlCrBN layer onto the cutting tool. a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n The coating, the (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n The coating is composed of the (Al) a Cr b Si c B d ) e N f Sublayer and the (Al) i Cr j Si k W l ) m N n The sublayers are periodically composed, specifically in the manner of: within one cycle, the (Al) layers are cyclically superimposed from the inside out. a Cr b Si c B d ) e N f Sublayer and the (Al) i Cr j Si k W l )m N n Sublayers, forming (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n Composite structural unit, the (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n Composite structural units are periodically stacked to form the (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n The coating process involves 6-8 cycles, during which AlCrSiB and AlCrSiW targets are alternately activated. The N2 pressure and target current are periodically adjusted to ensure the (Al...) coating... a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N nThe W and B elements in the coating exhibit periodic variations; in the high W concentration region, 5-10 nm nanocrystalline nc-WN phases are formed, while in the low W concentration region, Si elements are enriched to form amorphous α-Si3N4 phases that encapsulate the grain boundaries of the nc-WN phases. The process parameters are: temperature 450-550℃, N2 pressure periodically adjusted within the range of 0.02-0.05 mbar, negative bias voltage -60 to -100 V, duty cycle 60-70%, target current periodically adjusted within the range of 140-200 A; deposition time 40-280 min.

[0053] S5, regarding the (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n The composite-coated tool is obtained by cooling the multilayer tool. The composite-coated tool, from the inside out, comprises: the tool substrate, the CrB2 coating, the AlCrBN coating, and the (Al... a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n coating;

[0054] The cooling methods include natural cooling or controlled cooling to room temperature.

[0055] The initial cutting tools used in the following examples and comparative examples were WC-based cemented carbide, with a fracture toughness KIC ≥ 18.5 MPa·m. 1 / 2 The hardness is 1200-1400HV, and the average grain size of WC in the initial tool is 1.0-1.4μm.

[0056] The technical solution of this application will be further described below with reference to specific embodiments.

[0057] Example 1

[0058] This application provides a method for preparing a multi-element nano-alternating composite coated cutting tool, comprising the following steps:

[0059] S1. Obtain the initial tool, and perform pretreatment and etching on the initial tool to obtain the tool substrate;

[0060] The pretreatment process is as follows: the initial tool is cleaned using ultrasonic cleaning, and the surface of the initial tool is dried using nitrogen blowing or baking. The dried initial tool is then clamped on the rotating frame of the coating equipment, ensuring uniform clamping to guarantee coating uniformity. The rotating frame is placed in the vacuum chamber of the physical vapor deposition coating equipment, which is equipped with CrB2, AlCrB, AlCrSiB, and AlCrSiW targets.

[0061] The etching method is as follows: the vacuum chamber is evacuated to a vacuum and heated to 500°C. Ar gas is introduced at a flow rate of 125 sccm. A negative bias voltage of -200V is applied to etch the surface of the initial tool for 25 minutes to obtain the tool substrate.

[0062] S2. A CrB2 layer is deposited on the tool substrate to obtain a CrB2 layer tool; a CrB2 coating is deposited on the surface of the tool substrate; in the CrB2 coating, the atomic percentage of Cr element is 35 at.% and the atomic percentage of B element is 65 at.%; the thickness of the CrB2 coating is 0.2 μm;

[0063] The CrB2 layer deposition method is as follows: the CrB2 coating is deposited on the tool substrate using magnetron sputtering. The process parameters are: temperature of 600℃, negative bias voltage of -100V, CrB2 target sputtering power of 9000W, working pressure of 0.05mbar, and deposition time of 15min.

[0064] S3. An AlCrBN layer was deposited on the CrB2 layer tool to obtain an AlCrBN layer tool. The surface of the CrB2 layer tool was coated with an AlCrBN coating; the thickness of the AlCrBN coating was 0.3 μm.

[0065] The AlCrBN layer deposition method is as follows: an AlCrBN coating is deposited on a CrB2 layer tool using an arc ion plating process. An AlCrB target is used and N2 gas is introduced. The process parameters are: temperature 500℃, N2 pressure 0.04mbar, negative bias voltage -60V, arc current 170A, duty cycle 65%; deposition time 15min.

[0066] S4. Perform (Al) processing on the AlCrBN layer tool. a Cr b Si c B d ) e N f / (Al i Cr j Sik W l ) m N n Layer deposition to obtain (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n Layered cutting tools, AlCrBN layered cutting tools have Al deposited on their surface. a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n Coating; (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n The coating thickness is 2.5 μm, (Al a Cr b Si c B d ) e N f The sublayer thickness is 20 nm, (Al) i Cr j Si k W l ) m N n The thickness of a single sublayer is 20 nm.

[0067] (Al a Cr b Si c B d ) e N f / (Al i Cr j Si k W l )m N n The specific deposition method is as follows: An arc ion plating process is used to deposit AlCrBN layers onto the cutting tool. a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n Coating, (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n The coating is made of (Al) a Cr b Si c B d ) e N f Sublayer and (Al) i Cr j Si k W l ) m N n The sublayers are periodically composed, and the specific method of periodic composition is as follows: within one cycle, they are cyclically superimposed from the inside out (Al). a Cr b Si c B d ) e N f Sublayer and (Al) i Cr j Si k W l ) m N n Sublayers, forming (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N nComposite structural unit, (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n Composite structural units are formed by periodic superposition (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n The coating was applied in seven cycles, with AlCrSiB and AlCrSiW targets alternately used during the deposition process. The N2 pressure and target current were periodically adjusted to ensure the (Al...) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n The W and B elements in the coating exhibit periodic variations; in the high W concentration region, 5-10 nm nanocrystalline nc-WN phases are formed, while in the low W concentration region, Si elements are enriched to form amorphous α-Si3N4 phases that encapsulate the grain boundaries of the nc-WN phases. The process parameters are: temperature 500℃, negative bias voltage -80V, duty cycle 65%, deposition time 160 min, N2 pressure periodically adjusted within the range of 0.02-0.05 mbar (0.02 mbar→0.03 mbar→0.04 mbar→0.05 mbar→0.04 mbar→0.03 mbar→0.02 mbar), and target current periodically adjusted within the range of 140-200 A (140 A→160 A→180 A→200 A→180 A→160 A→140 A cycle).

[0068] S5, for (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n The composite coated tool is obtained by naturally cooling the multilayer tool. From the inside out, the composite coated tool consists of: a tool substrate, a CrB2 coating, an AlCrBN coating, and an (Al... a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n Coatings; CrB2 coating, AlCrBN coating and (Al a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n The total thickness of the coating is 3 μm.

[0069] (Al a Cr b Si c B d ) e N f Sublayer contains amorphous BN x Phase, amorphous BN x The atomic content of the phase does not exceed (Al) a Cr b Si c B d ) e N f 10% of the total atomic content of the sublayer;

[0070] (Al i Cr j Si k W l ) m N n The sublayer contains an amorphous Si3N4 phase, the atomic content of which does not exceed (Al). i Cr j Si k W l )m N n 20% of the total atomic content of the sublayer;

[0071] (Al a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n The composite structural unit also includes:

[0072] (Al a Cr b Si c B d ) e N f The atomic concentration of boron (B) in the sublayer decreases and then increases from the inside to the outside along the cyclic superposition direction. In particular, amorphous BN precipitates in regions where the B concentration is higher than 8 at.%. x Mutually;

[0073] (Al i Cr j Si k W l ) m N n The atomic concentration of W in the sublayer shows a trend of increasing from low to high and then decreasing from the inside to the outside along the cyclic superposition direction. Among them, the region with a W concentration higher than 8 at.% constitutes a high W concentration region. In the high W concentration region, nanocrystalline nc-WN phase with an average grain size of 5-10 nm precipitates. The region with a W concentration lower than 6 at.% constitutes a low W concentration region. In the low W concentration region, Si is enriched and precipitates amorphous α-Si3N4 phase. The grain boundaries of the nc-WN phase are wrapped by the amorphous α-Si3N4 phase.

[0074] In (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n In a composite structural unit, counting from the inside out along the cyclic stacking direction,

[0075] Layer 1 (Al) a Crb Si c B d ) e N f Sublayer and Layer 1 (Al) i Cr j Si k W l ) m N n In the sublayer: the values ​​of a, b, c, d, e, and f are 0.55, 0.32, 0.03, 0.1, 0.48, and 0.52, respectively; the values ​​of i, j, k, l, m, and n are 0.55, 0.35, 0.07, 0.03, 0.49, and 0.51, respectively.

[0076] Layer 4 (Al) a Cr b Si c B d ) e N f Sublayer and 4th layer (Al) i Cr j Si k W l ) m N n In the sublayer: the values ​​of a, b, c, d, e, and f are 0.57, 0.34, 0.06, 0.03, 0.5, and 0.5, respectively; the values ​​of i, j, k, l, m, and n are 0.58, 0.32, 0.01, 0.09, 0.51, and 0.49, respectively.

[0077] 7th layer (Al) a Cr b Si c B d ) e N f Sublayer and 7th layer (Al) i Cr j Si k W l ) m N n In the sublayer: the values ​​of a, b, c, d, e, and f are 0.55, 0.34, 0.02, 0.09, 0.49, and 0.51, respectively; the values ​​of i, j, k, l, m, and n are 0.6, 0.3, 0.07, 0.03, 0.48, and 0.52, respectively.

[0078] With a constant bias voltage, as the current increases, the sputtering power of the target increases. Since the elemental mass of boron (B) is much lower than that of al, Cr, and Si, the sputtering energy is relatively low at 140A, resulting in a higher B content. As the current increases (140A→200A), the sputtering energy and ion bombardment energy increase, and the anti-sputtering effect is enhanced. Due to the smaller mass of B, more B atoms are bombarded back into the vacuum chamber under the bombardment of high-energy ions compared to al, Cr, and Si, leading to a decrease in the B content in the coating. When the current increases to 200A, the sputtering power reaches its maximum, the anti-sputtering effect reaches its maximum, and the B content in the coating is at its lowest. As the current decreases to 140A, the B content gradually increases again.

[0079] With a constant bias voltage, as the current increases, the target power increases. Since the elemental mass of W is much higher than that of Al, Cr, and Si, the sputtering energy is relatively low at 140A, resulting in a low W content. As the current increases, the sputtering energy and ion bombardment energy increase, enhancing the anti-sputtering effect. However, due to the larger W mass, fewer W atoms are bombarded back into the vacuum chamber compared to Al, Cr, and Si under high-energy ion bombardment, leading to an increase in the W content in the coating. When the current increases to 200A, the sputtering power reaches its maximum, the anti-sputtering effect reaches its maximum, and the W content in the coating is highest. As the current decreases to 140A, the W content gradually decreases again.

[0080] As the current is periodically adjusted within the range of 140-200A (140A→160A→180A→200A→180A→160A→140A cycle), the concentration of boron in the AlCrSiBN coating first decreases and then increases, while the concentration of w in the AlCrSiWN coating first increases and then decreases.

[0081] Due to the change in target current, the sputtering power of the target increases, resulting in an increase in the number of ions sputtered from the target. This leads to more plasma in the vacuum chamber, which means that more N atoms are needed to combine with it. Therefore, while adjusting the target current, it is necessary to adjust it simultaneously. The current determines the "sputtering amount of metal ions," and the N2 partial pressure determines the "reaction amount of nitrogen ions." The two must be matched in proportion. Changes in current will directly change the output scale of metal ions. If the N2 partial pressure is not adjusted accordingly, there will be problems of insufficient or excessive nitrogen ions.

[0082] The prepared composite coated cutting tool was tested, and the results showed that the nanohardness of the composite coated cutting tool was 40 GPa, the bonding strength between the tool substrate and the coating was 77 N, the coefficient of friction was 0.32, and the coating weight increased by 4.47 mg after holding at 900℃ for 30 min.

[0083] Example 2

[0084] The difference between this embodiment and Embodiment 1 is that:

[0085] S2. Process parameters are: temperature 650℃, negative bias voltage -80V;

[0086] S3. The process parameters are: temperature 550℃, negative bias voltage -40V.

[0087] S4. The process parameters are: temperature 550℃, negative bias voltage -60V.

[0088] The thickness of CrB2 is 0.18 μm, the thickness of AlCrBN is 0.22 μm, and the thickness of (Al...) is... a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n The coating thickness is 2.1 μm;

[0089] In (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n In a composite structural unit, counting from the inside out along the cyclic stacking direction,

[0090] Layer 1 (Al) a Cr b Si c B d ) e N f Sublayer and Layer 1 (Al) i Cr j Si k W l ) m N n In the sublayer: the values ​​of a, b, c, d, e, and f are 0.55, 0.32, 0.04, 0.09, 0.49, and 0.51, respectively; the values ​​of i, j, k, l, m, and n are 0.55, 0.35, 0.08, 0.02, 0.5, and 0.5, respectively.

[0091] Layer 4 (Al) a Cr b Si c B d ) e N f Sublayer and 4th layer (Al) i Cr j Si k W l ) m N n In the sublayer: the values ​​of a, b, c, d, e, and f are 0.57, 0.34, 0.07, 0.02, 0.51, and 0.49, respectively; the values ​​of i, j, k, l, m, and n are 0.57, 0.32, 0.01, 0.1, 0.5, and 0.5, respectively.

[0092] 7th layer (Al) a Cr b Si c B d ) e N f Sublayer and 7th layer (Al) i Cr j Si k W l ) m N n In the sublayer: the values ​​of a, b, c, d, e, and f are 0.55, 0.33, 0.03, 0.09, 0.49, and 0.51, respectively; the values ​​of i, j, k, l, m, and n are 0.6, 0.3, 0.08, 0.02, 0.49, and 0.51, respectively.

[0093] The prepared composite coated cutting tool was tested, and the results showed that the nanohardness of the composite coated cutting tool was 38 GPa, the bonding strength between the tool substrate and the coating was 75 N, the coefficient of friction was 0.33, and the coating weight increased by 4.56 mg after holding at 900℃ for 30 min.

[0094] Example 3

[0095] The difference between this embodiment and Embodiment 1 is that:

[0096] S2. The process parameters are: temperature 550℃, negative bias voltage -120V;

[0097] S3. The process parameters are: temperature 450℃, negative bias voltage -80V.

[0098] S4. The process parameters are: temperature 450℃, negative bias voltage -100V.

[0099] The thickness of CrB2 is 0.25 μm, the thickness of AlCrBN is 0.4 μm, and the thickness of (Al...) is... aCr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n The coating thickness is 3.0 μm;

[0100] In (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n In a composite structural unit, counting from the inside out along the cyclic stacking direction,

[0101] Layer 1 (Al) a Cr b Si c B d ) e N f Sublayer and Layer 1 (Al) i Cr j Si k W l ) m N n In the sublayer: the values ​​of a, b, c, d, e, and f are 0.56, 0.31, 0.03, 0.1, 0.5, and 0.5, respectively; the values ​​of i, j, k, l, m, and n are 0.56, 0.34, 0.09, 0.01, 0.51, and 0.49, respectively.

[0102] Layer 4 (Al) a Cr b Si c B d ) e N f Sublayer and 4th layer (Al) i Cr j Si k W l ) m N nIn the sublayer: the values ​​of a, b, c, d, e, and f are 0.57, 0.33, 0.08, 0.02, 0.49, and 0.51, respectively; the values ​​of i, j, k, l, m, and n are 0.58, 0.31, 0.02, 0.09, 0.5, and 0.5, respectively.

[0103] 7th layer (Al) a Cr b Si c B d ) e N f Sublayer and 7th layer (Al) i Cr j Si k W l ) m N n In the sublayer: the values ​​of a, b, c, d, e, and f are 0.58, 0.32, 0.01, 0.09, 0.51, and 0.49, respectively; the values ​​of i, j, k, l, m, and n are 0.59, 0.31, 0.08, 0.02, 0.51, and 0.49, respectively.

[0104] The prepared composite coated cutting tool was tested, and the results showed that the nanohardness of the composite coated cutting tool was 44 GPa, the bonding strength between the tool substrate and the coating was 70 N, the coefficient of friction was 0.32, and the coating weight increased by 4.31 mg after holding at 900℃ for 30 min.

[0105] Comparative Example 1

[0106] The difference between this comparative example and Example 1 is that step S2 is omitted;

[0107] The prepared composite coated cutting tool was tested, and the results showed that the nanohardness of the composite coated cutting tool was 39 GPa, the bonding strength between the tool substrate and the coating was 60 N, the friction coefficient was 0.32, and the coating weight increased by 4.45 mg after holding at 900℃ for 30 min.

[0108] Comparative Example 2

[0109] The difference between this comparative example and Example 1 is that step S3 is omitted;

[0110] The prepared composite coated cutting tool was tested, and the results showed that the nanohardness of the composite coated cutting tool was 37 GPa, the bonding strength between the tool substrate and the coating was 60 N, the coefficient of friction was 0.32, and the coating weight increased by 4.45 mg after holding at 900℃ for 30 min.

[0111] Comparative Example 3

[0112] The difference between this comparative example and Example 1 is that step S4 is omitted;

[0113] The prepared composite coated cutting tool was tested, and the results showed that the nanohardness of the composite coated cutting tool was 34 GPa, the bonding strength between the tool substrate and the coating was 75 N, the coefficient of friction was 0.45, and the coating weight increased by 5.12 mg after holding at 900℃ for 30 min.

[0114] Comparative Example 4

[0115] The difference between this comparative example and Example 1 is that no Al is deposited in step S4. i Cr j Si k W l ) m N n Sub-layer;

[0116] The prepared composite coated cutting tool was tested, and the results showed that the nanohardness of the composite coated cutting tool was 35 GPa, the bonding strength between the tool substrate and the coating was 75 N, the friction coefficient was 0.41, and the coating weight increased by 4.77 mg after holding at 900℃ for 30 min.

[0117] Comparative Example 5

[0118] The difference between this comparative example and Example 1 is that no Al is deposited in step S4. a Cr b Si c B d ) e N f Sub-layer;

[0119] The prepared composite coated cutting tool was tested, and the results showed that the nanohardness of the composite coated cutting tool was 37 GPa, the bonding strength between the tool substrate and the coating was 75 N, the coefficient of friction was 0.37, and the coating weight increased by 4.52 mg after holding at 900℃ for 30 min.

[0120] Comparative Example 6

[0121] The difference between this comparative example and Example 1 is that the cutting tool was not coated;

[0122] The prepared cutting tool was tested, and the results showed that the coefficient of friction was 0.56, and the coating weight increased by 6.26 mg after holding at 900℃ for 30 min.

[0123] The cutting performance of the composite coated tools prepared according to the embodiments and comparative examples of this application was tested below, under the following test conditions:

[0124] Material: 4340 steel; Insert type: RPHT120408E-MM3 carbide end mill; Cutting conditions: Cutting speed Vc=180m / min, depth of cut ap=1.2mm, feed per revolution f=0.3mm / r, width of cut ae=20mm, water cooling.

[0125] As shown in Table 1, Table 1 shows the measurement results of the back face wear of the cutting tool after different cutting times. The wear of the back face of the cutting tool was measured using an optical ultra-depth-of-field microscope with a graduated scale.

[0126] Table 1

[0127]

[0128] As can be seen from Table 1 (where "--" indicates that the tools have all failed), under the same tool substrate and cutting conditions, the cutting performance of the composite coated tools of this application is better than that of the comparative examples.

[0129] Based on the above embodiments and comparative examples, Embodiment 1, in conjunction with Comparative Example 1, demonstrates that adding a CrB2 underlayer between the functional layers of the substrate can improve the service life of composite coated tools to a certain extent. The main reasons are as follows: On the one hand, this underlayer alleviates severe interface stress concentration, preventing rapid cracking of the coating interface during cutting, which would eventually lead to the overall peeling off of the coating and complete tool failure; on the other hand, it prevents elements in the substrate from diffusing into the upper coating at high cutting temperatures, causing the coating to soften, and also prevents elements such as N and Al in the upper coating from diffusing into the substrate and damaging the substrate structure.

[0130] Example 1, combined with Comparative Example 2, shows that adding an AlCrBN transition layer between the underlayer and the transition layer can eliminate abrupt changes in composition and properties that cause interfacial cracks, thereby affecting coating performance and improving coating life to a certain extent.

[0131] Example 1, in conjunction with Comparative Examples 3, 4, 5, and 6, shows that (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n As the nano-alternating functional layer of the tool composite coating, the coating is the core of the entire coating system's performance. Its advantages are not due to the superposition of the performance of a single phase, but rather through (Al) a Cr b Si c B d )e N f Sublayer and (Al) i Cr j Si k W l ) m N n The periodic nano-alternating design of the sublayers, combined with the synergistic effect of multiple elements such as B, W, Si, and N, achieves a comprehensive and synergistic improvement in the service life of the cutting tool, enhancing its hardness, toughness, wear resistance, high-temperature oxidation resistance, and chipping resistance.

[0132] The above description is only a preferred embodiment of this application and does not limit the patent scope of this application. All equivalent structural transformations made using the content of this application's specification under the inventive concept of this application, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this application.

Claims

1. A multi-element nano-alternating composite coating cutting tool, characterized in that, The composite coated cutting tool, from the inside out, comprises: a tool substrate, a CrB2 coating, an AlCrBN coating, and (Al... a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n The coating, the (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n The coating is made of (Al) a Cr b Si c B d ) e N f Sublayer and (Al) i Cr j Si k W l ) m N n The sublayers are periodically composed, specifically in the manner of: within one cycle, the (Al) layers are cyclically superimposed from the inside out. a Cr b Si c B d ) e N f Sublayer and the (Al) i Cr j Si k W l ) m N n Sublayers, forming (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n Composite structural unit, the (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n Composite structural units are periodically stacked to form the (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n The coating is subjected to 6-8 cycles; the (Al) a Cr b Si c B d ) e N f The ratio of a, b, c, d in the sublayer is (0.55-0.60):(0.30-0.40):(0-0.10):(0-0.10), where (Al) a Cr b Si c B d ) e N f The ratio of e to f in the sublayer is (0.9-1.1):1, where (Al) i Cr j Si k W l ) m N n The ratio of i, j, k, l in the sublayer is (0.55-0.60):(0.30-0.40):(0-0.10):(0-0.10), where (Al) i Cr j Si k W l ) m N n The ratio of m to n in the sublayer is (0.9-1.1):1, where c, d, k, and l are not set to 0.

2. The multi-element nano-alternating composite coating cutting tool according to claim 1, characterized in that, The thickness of the CrB2 coating is 0.1-0.3 μm, and the thickness of the AlCrBN coating is 0.1-0.5 μm. a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n The coating thickness is 1.5-3.5 μm, and the (Al) a Cr b Si c B d ) e N f The thickness of the sublayer is 5-35 nm, and the (Al) i Cr j Si k W l ) m N n The single-layer thickness of the sublayer is 5-35 nm, and the CrB2 coating, the AlCrBN coating, and the (Al a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n The total thickness of the coating is 1.7-4.3 μm.

3. The multi-element nano-alternating composite coating cutting tool according to claim 1, characterized in that, The (Al) a Cr b Si c B d ) e N f Sublayer contains amorphous BN x Phase, the amorphous BN x The atomic content of the phase does not exceed that of Al. a Cr b Si c B d ) e N f 10% of the total atomic content of the sublayer.

4. The multi-element nano-alternating composite coating cutting tool according to claim 1, characterized in that, The (Al) i Cr j Si k W l ) m N n The sublayer contains an amorphous Si3N4 phase, the atomic content of which does not exceed that of Al. i Cr j Si k W l ) m N n 20% of the total atomic content of the sublayer.

5. The multi-element nano-alternating composite coating cutting tool according to claim 1, characterized in that, The (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n The composite structural unit also includes: the (Al) a Cr b Si c B d ) e N f The atomic concentration of boron (B) in the sublayer decreases and then increases from the inside to the outside along the cyclic superposition direction. In particular, amorphous BN precipitates in regions where the B concentration is higher than 8 at.%. x Mutually.

6. The multi-element nano-alternating composite coating cutting tool according to claim 1, characterized in that, The (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n The composite structural unit also includes: the (Al) i Cr j Si k W l ) m N n The atomic concentration of W element in the sublayer shows a trend of increasing from low to high and then decreasing from the inside to the outside along the cyclic superposition direction. Among them, the region with W element concentration higher than 8 at.% constitutes a high W concentration region, in which nanocrystalline nc-WN phase with an average grain size of 5-10 nm precipitates. The region with W element concentration lower than 6 at.% constitutes a low W concentration region, in which Si element is enriched and precipitates amorphous α-Si3N4 phase, and the grain boundaries of the nc-WN phase are wrapped by the amorphous α-Si3N4 phase.

7. A method for preparing a multi-element nano-alternating composite coated cutting tool, characterized in that, This method is used to prepare a multi-element nano-alternating composite coated cutting tool according to any one of claims 1-6, the preparation method comprising the following steps: S1. Obtain the initial tool, and perform pretreatment and etching on the initial tool to obtain the tool substrate; S2. A CrB2 layer is deposited on the tool substrate to obtain a CrB2 layered tool; the CrB2 coating is deposited on the surface of the tool substrate. S3. An AlCrBN layer is deposited on the CrB2 layer tool to obtain an AlCrBN layer tool, wherein the surface of the CrB2 layer tool is coated with the AlCrBN coating. S4. Perform (Al) processing on the AlCrBN layer tool. a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n Layer deposition to obtain (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n Layered cutting tool, the surface of the AlCrBN layered cutting tool is deposited with Al(Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n coating; S5, regarding the (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n The composite-coated tool is obtained by cooling the multilayer tool. The composite-coated tool, from the inside out, comprises: the tool substrate, the CrB2 coating, the AlCrBN coating, and the (Al... a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n coating.

8. The method for preparing a multi-element nano-alternating composite coated cutting tool according to claim 7, characterized in that, In step S1, the pretreatment method specifically includes: cleaning the initial tool using ultrasonic cleaning, and drying the surface of the initial tool using nitrogen blowing or drying; clamping the dried initial tool on the rotating frame of the coating equipment, ensuring uniform clamping to guarantee coating uniformity; placing the rotating frame in the vacuum chamber of the physical vapor deposition coating equipment, which is equipped with CrB2 target, AlCrB target, AlCrSiB target and AlCrSiW target; The etching method is as follows: the vacuum chamber is evacuated to a vacuum and heated to 450-550°C, Ar gas is introduced at a flow rate of 100-150 sccm, and a negative bias voltage of -180V to -220V is applied to etch the surface of the initial tool for 15-30 minutes to obtain the tool substrate. In step S2, the CrB2 layer is deposited in the following manner: the CrB2 coating is deposited on the tool substrate using magnetron sputtering. The process parameters are: temperature 550-650℃, negative bias voltage -80V to -120V, CrB2 target sputtering power 6000-12000W, working pressure 0.04-0.06mbar, and deposition time 5-25min. In step S3, the AlCrBN layer is deposited in the following manner: an arc ion plating process is used to deposit the AlCrBN coating on the CrB2 layer tool, wherein an AlCrB target is used and N2 gas is introduced, and the process parameters are: temperature 450-550℃, negative bias voltage -40 to -80V, arc current 140-200A, duty cycle 60-70%; the pressure of the N2 is 0.03-0.05mbar, and the deposition time is 5-25min. In step S4, the (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n The specific deposition method is as follows: Arc ion plating is used to deposit the AlCrBN layer onto the cutting tool. a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n The coating, the (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n The coating is composed of the (Al) a Cr b Si c B d ) e N f Sublayer and the (Al) i Cr j Si k W l ) m N n The sublayers are periodically composed, specifically in the manner of: within one cycle, the (Al) layers are cyclically superimposed from the inside out. a Cr b Si c B d ) e N f Sublayer and the (Al) i Cr j Si k W l ) m N n Sublayers, forming (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n Composite structural unit, the (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n Composite structural units are periodically stacked to form the (Al) a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n The coating process involves 6-8 cycles, during which AlCrSiB and AlCrSiW targets are alternately activated. The N2 pressure and target current are periodically adjusted to ensure the (Al...) coating... a Cr b Si c B d ) e N f / (Al i Cr j Si k W l ) m N n The W and B elements in the coating exhibit periodic variations; in the high W concentration region, 5-10 nm nanocrystalline nc-WN phases are formed, while in the low W concentration region, Si elements are enriched to form amorphous α-Si3N4 phases that encapsulate the grain boundaries of the nc-WN phases. The process parameters are: temperature 450-550℃, N2 pressure periodically adjusted within the range of 0.02-0.05 mbar, negative bias voltage -60 to -100 V, duty cycle 60-70%, target current periodically adjusted within the range of 140-200 A; deposition time 40-280 min. In step S5, the cooling method includes natural cooling or controlled cooling to room temperature.

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