Cutting tool containing nanocomposite multilayer coating and preparation method thereof

Abstract

The invention discloses a cutting tool containing a nano-composite multi-layer coating and a preparation method thereof. The cutting tool comprises a tool substrate and a nano-composite multi-layer coating deposited on the surface of the tool substrate. The nano-composite multi-layer coating comprises Cr deposited alternately. 1‑a‑ b Al a Me b N layer and NbN layer, 0.3≤a≤0.7, 0≤b≤0.2, Cr 1‑a‑b Al a Me b The N layer is a face-centered cubic structure, and the NbN layer is a mixed structure of cubic NbN and hexagonal NbN. The preparation method includes pre-treating the tool substrate, first depositing the filter layer by PVD, and then alternately depositing Cr 1‑a‑b Al a Me b The cutting tool containing the nano-composite multi-layer coating of the present invention has low stress, high heat insulation and excellent anti-crater wear performance, and the preparation method is simple in process, conventional in equipment and low in production cost.

Description

Technical Field

[0001] The invention belongs to the field of cutting tools, and relates to a cutting tool containing a nano-composite multi-layer coating and a preparation method thereof, and specifically relates to a cutting tool containing a CrAlMeN / NbN nano-composite multi-layer coating and a preparation method thereof. Background Art

[0002] Cutting tools are known as the teeth of industrial manufacturing and are widely used in the automotive, shipbuilding, aerospace and 3C industries. In addition to the structural design and substrate of cutting tools, surface coating technology is an important factor affecting the performance of cutting tools. Plating hard coatings such as TiAlN or CrAlN on the surface of cutting tools can significantly improve their wear resistance and heat resistance, and improve the performance of cutting tools. However, the performance of TiAlN coatings is closely related to the Al content. With the increase of Al content, the oxidation resistance and hardness of TiAlN coatings are improved. However, when the Al content exceeds its solid solubility limit in the TiN lattice, w-AlN phase will be formed, and the hardness and heat resistance will be significantly reduced. Moreover, when the temperature reaches 850°C, the TiAlN coating will be completely oxidized. Compared with TiAlN coatings, the oxidation resistance temperature of CrAlN coatings can reach 1000°C. However, CrAlN coatings will decompose at around 900°C, and Cr will precipitate. 2 With the rapid development of the manufacturing industry, various new materials emerge in an endless stream. In response to these increasingly difficult-to-process materials, traditional TiAlN and CrAlN coatings can no longer meet market demand.

[0003] CN104175682A discloses a TiAlN / CrAlN multilayer coating tool and a preparation method thereof, which combines the advantages of TiAlN and CrAlN coatings. By changing the thickness of the modulation period, the comprehensive performance of the coating can be improved. However, in actual application, it is found that the hardness of the TiAlN / CrAlN multilayer coating is low and the wear resistance is limited. In addition, due to the presence of Ti element, loose and porous TiO 2 The oxide layer, with the increase of temperature, is accompanied by the formation of a-TiO 2 To r-TiO 2 Phase change, loose and porous TiO 2 The volume changes caused by the structure and phase change process reduce the density of the oxide layer, which limits the improvement of the coating's anti-oxidation performance.

[0004] Adding third elements such as Si and B to CrAlN coatings to form quaternary system coatings such as CrAlSiN and CrAlBN can not only avoid the harmful effects of Ti on the oxidation resistance of the coatings and maintain the excellent oxidation resistance of CrAlN coatings, but also inhibit the fracture of Cr-N bonds in CrAlN coatings to a certain extent and improve their thermal stability. However, the addition of elements such as Si and B will increase the stress of the coating, reduce the toughness of the coating, cause the coating to peel off prematurely, and reduce the tool life. On the other hand, third components such as Si and B will increase the friction coefficient of CrAlN coatings, reduce the quality of the machined surface, increase the temperature of the cutting area, and lead to the deterioration of the cutting process. Third, CrAlN-based coatings such as CrAlSiN and CrAlBN are still easy to diffuse with difficult-to-process materials such as stainless steel and high-temperature alloys with high Cr content in high temperature environments, forming crescent wear and reducing the durability of the coating.

[0005] Based on the above analysis, the existing coatings still have much room for improvement in terms of reducing coating stress, improving coating toughness, reducing cutting heat, and resisting crater wear. Summary of the invention

[0006] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a cutting tool containing a nano-composite multi-layer coating with low stress, high heat insulation and excellent anti-crater wear performance and a preparation method thereof.

[0007] In order to solve the above technical problems, the present invention adopts the following technical solutions.

[0008] A cutting tool containing a nano-composite multi-layer coating, comprising a tool substrate and a nano-composite multi-layer coating deposited on the surface of the tool substrate, wherein the nano-composite multi-layer coating comprises alternately deposited Cr 1-a-b Al a Me b N layer and NbN layer, the Me element is at least one of Ti, Zr, Hf, V, Nb, Ta, Ru, Si, B, Y and W, wherein 0.3≤a≤0.7, 0≤b≤0.2, the Cr 1-a-b Al a Me b The N layer is a face-centered cubic structure, and the NbN layer is a mixed structure of cubic NbN and hexagonal NbN, wherein the hexagonal NbN presents a (100) preferred orientation, and the orientation factor is 1.2≤τ h(100) ≤3.5.

[0009] The above-mentioned cutting tool containing nanocomposite multilayer coating, preferably, the (111) diffraction peak intensity I of the cubic structure NbN in the NbN layer is c-NbN(111) The (100) diffraction peak intensity I of hexagonal NbN h-NbN(100)The ratio is 0.2≤I c-NbN(111) / I h-NbN(100) ≤0.6.

[0010] The above-mentioned cutting tool containing nanocomposite multilayer coating, preferably, the Cr 1-a-b Al a Me b The single layer thickness of the N layer is 2nm to 300nm, and the single layer thickness of the NbN layer is 2nm to 300nm. 1-a-b Al a Me b When the single layer thickness of the N layer and the NbN layer is less than 2nm, the interface between the two is in a mixed state, which will reduce the mechanical properties of the coating and increase the residual stress of the coating. 1-a-b Al a Me b When the single layer thickness of the N layer and the NbN layer is greater than 300 nm, the bonding strength between the layers is weakened and the toughness of the coating is reduced.

[0011] For the above-mentioned cutting tool containing the nano-composite multi-layer coating, preferably, the thickness of the nano-composite multi-layer coating is 0.5 μm to 8.0 μm.

[0012] The above-mentioned cutting tool containing nanocomposite multilayer coating, preferably, the nanocomposite multilayer coating is "Cr 1-a-b Al a Me b "N layer to NbN layer" is a cycle.

[0013] For the above-mentioned cutting tool containing nano-composite multi-layer coating, preferably, a transition layer is provided between the nano-composite multi-layer coating and the tool substrate.

[0014] The above-mentioned cutting tool containing nanocomposite multilayer coating, preferably, the transition layer is Cr 1-x Al x N layers, 0≤x≤0.7.

[0015] In the above-mentioned cutting tool containing nanocomposite multilayer coating, preferably, the transition layer is Ti 1-y Al y N layers, 0≤y≤0.6.

[0016] In the above-mentioned cutting tool containing nano-composite multi-layer coating, preferably, the transition layer is a face-centered cubic structure.

[0017] For the above-mentioned cutting tool containing nano-composite multi-layer coating, preferably, the thickness of the transition layer is 0.1 μm to 2.0 μm.

[0018] For the above-mentioned cutting tool containing nano-composite multi-layer coating, preferably, the total coating thickness of the tool is 0.6 μm to 10.0 μm.

[0019] For the above-mentioned cutting tool containing nano-composite multi-layer coating, preferably, the material of the tool substrate is cemented carbide, metal ceramic, high-speed steel or cubic boron nitride sintered body.

[0020] As a general technical concept, the present invention also provides a method for preparing the above-mentioned cutting tool containing the nanocomposite multilayer coating, comprising the following steps:

[0021] S1. Pre-treating the surface of the cutting tool substrate, wherein the pre-treatment includes sandblasting and ultrasonic cleaning;

[0022] S2, ion etching the pretreated cutting tool substrate to further clean the surface;

[0023] S3, using PVD method to deposit transition layer CrAl target or TiAl target on the surface of cutting tool substrate 1- x Al x N layer or Ti 1-y Al y N layer, deposition temperature is 400℃~600℃, deposition gas pressure is 1.0Pa~6.0Pa, substrate bias is -30V~-120V, CrAl or TiAl target current is 130A~200A;

[0024] S4, using PVD method to deposit CrAlMe target and Nb target alternately on the transition layer 1-a-b Al a Me b N nanolayer and NbN nanolayer to form a CrAlMeN / NbN nanocomposite multilayer coating, the deposition temperature is 400℃~600℃, the deposition gas pressure is 1.0Pa~6.0Pa, the substrate bias is -30V~-120V, and the currents of the CrAlMe target and the Nb target are 130A~200A and 150A~200A respectively.

[0025] In the technical solution of the present invention, it is found through experimental research that by cooperating with Cr 1-a-b Al a Me b N and NbN are used to design nano multilayer structures. First, Cr 1-a-b Al a Me b The N coating and NbN coating synergistically form Cr 1-a-b Al a Me bN / NbN nanocomposite multilayer coating, the NbN layer with high thermal stability can inhibit the Cr 1-a-b Al a Me b The thermal decomposition of N further improves the thermal stability of the coating; secondly, Cr 1-a-b Al a Me b The thermal conductivity of the N coating is significantly lower than that of the TiAlN coating. 1-a-b Al a Me b The N layer (rather than TiAlN coating or TiAlN / CrAlN coating) and the high thermal stability NbN layer can enhance the thermal barrier effect of the coating, take away more cutting heat from the chips, and thus increase the service life of the tool. Third, the NbN coating has excellent chemical inertness (compared with Al 2 O 3 Coating similar), interspersed with Cr 1-a-b Al a Me b N coating can significantly improve the performance of the coating when processing difficult-to-process materials such as stainless steel and high-temperature alloys with a high Cr content, reduce diffusion wear, and effectively reduce the crater wear on the front cutting edge.

[0026] In each technical solution of the present invention, the tool can be various cutting tools known in the art, such as solid carbide milling cutters, CNC milling blades, drill bits and CNC turning blades, etc., and the substrate can be cemented carbide, metal ceramics, high-speed steel or superhard materials.

[0027] Compared with the prior art, the advantages of the present invention are:

[0028] 1. The present invention provides a Cr-containing 1-a-b Al a Me b N and NbN containing nanocomposite multilayer coating cutting tools, synergistic Cr 1-a-b Al a Me b The low thermal conductivity of the N layer and the high thermal stability and chemical inertness of the NbN layer provide an effective thermal barrier protection for the cutting tool, taking more cutting heat away with the chips, reducing the cutting heat in the cutting area, protecting the cutting edge, and increasing the tool life.

[0029] 2. The present invention adopts Cr 1-a-b Al a Me b The N layer and the NbN layer form a nanocomposite multilayer coating. The NbN layer with high thermal stability can effectively inhibit the Cr 1-a-b Al a Meb The thermal decomposition of N further improves the thermal stability of the coating.

[0030] 3. The present invention utilizes the excellent chemical inertness of the NbN coating, which will not react or diffuse with the active elements in the processed material. 1-a-b Al a Me b Cr is formed between N coatings 1-a-b Al a Me b N / NbN nanocomposite multilayer coating can significantly reduce diffusion wear and effectively reduce the crater wear on the front cutting edge.

[0031] 4. The present invention adopts Cr 1-a-b Al a Me b The N layer and the NbN layer are combined to form a nanocomposite multilayer coating, which alternately interrupts the Cr 1-a-b Al a Me b The growth of N layer and NbN layer makes Cr 1-a-b Al a Me b The grains of the N layer and the NbN layer are repeatedly recrystallized, which effectively reduces the stress of the coating and further enhances the toughness of the coating.

[0032] 5. The preparation method of the nano-composite multi-layer coating cutting tool of the present invention has the characteristics of simple process, low equipment requirements and low production cost, which can meet the needs of modern cutting processing and greatly extend the service life of the cutting tool. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a schematic diagram of the structure of the cutting tool coating according to Example 1 of the present invention.

[0034] Legend:

[0035] 1. Transition layer; 2. Nanocomposite multilayer coating; 21. Cr 1-a-b Al a Me b N layer; 22. NbN layer; 3. Tool substrate. DETAILED DESCRIPTION

[0036] The present invention is further described below in conjunction with the accompanying drawings and specific preferred embodiments, but the protection scope of the present invention is not limited thereby. The materials and instruments used in the following embodiments are all commercially available.

[0037] Example 1

[0038] A cutting tool containing a nanocomposite multilayer coating of the present invention, such as Figure 1As shown, the tool substrate 3 and the nanocomposite multilayer coating 2 deposited on the tool substrate 3 are made of Cr 1-a-b Al a Me b The N layer 21 and the NbN layer 22 are alternately deposited to form Cr 1-a-b Al a Me b N / NbN periodic nano multilayer coating, where a=0.70, b=0, Cr 0.30 Al 0.70 The single layer thickness of the N nanolayer is 7 nm, the single layer thickness of the NbN nanolayer is 7 nm, and the thickness of the nanocomposite multilayer coating 2 is 3.5 μm. 0.30 Al 0.70 The N nanolayer is a face-centered cubic structure, and the NbN nanolayer is a mixed structure of cubic NbN and hexagonal NbN. In addition, the hexagonal NbN in the NbN nanolayer presents a (100) preferred orientation, and the orientation factor τ h(100) =2.1.

[0039] In this embodiment, the (111) diffraction peak intensity I of the cubic NbN layer is c-NbN(111) The (100) diffraction peak intensity I of hexagonal NbN h-NbN(100) Ratio I c-NbN (111) / I h-NbN(100) =0.4.

[0040] In this embodiment, a transition layer 1 is provided between the nanocomposite multilayer coating 2 and the tool substrate 3, that is, starting from the surface of the tool substrate 3, there are the transition layer 1 and the nanocomposite multilayer coating 2 in sequence, and the transition layer 1 is Cr 1-x Al x N layer, where x = 0.70, Cr 0.30 Al 0.70 The thickness of N layer is 0.20 μm, and the transition layer Cr 0.30 Al 0.70 The N layer has a face-centered cubic structure.

[0041] In this embodiment, the Cr in the nanocomposite multilayer coating 2 0.30 Al 0.70 The N nanolayer is below the NbN nanolayer, but is not limited thereto. The Cr 1-a-b Al a Me b The N nanolayer and the NbN nanolayer may be equal, for example, the NbN nanolayer may be 1-a Al a N nanolayers below.

[0042] In this embodiment, the cutting tool is a cemented carbide indexable insert, the Co content is 10wt.%, the rest is WC, and the insert model is CNMG120408.

[0043] A method for preparing a cutting tool containing a nanocomposite multilayer coating according to the present embodiment comprises the following steps:

[0044] S1: Use a CNMG120408 carbide blade as the tool base, and pre-clean the tool base, including surface sandblasting and ultrasonic cleaning;

[0045] S2: performing Ar ion etching on the pretreated tool substrate;

[0046] S3: After Ar ion etching, the transition layer Cr is first deposited on the surface of the tool substrate using the PVD method. 0.30 Al 0.70 N layer, deposition temperature is 500℃, deposition pressure is 3.2Pa, substrate bias is -60V, target current is 160A, Cr 0.30 Al 0.70 The thickness of the N layer is 0.20 μm;

[0047] S4: Alternately deposit Cr on top of transition layer 1 0.30 Al 0.70 N nanolayer and NbN nanolayer, forming Cr 0.30 Al 0.70 N / NbN nanocomposite multilayer coating, deposition temperature is 500℃, deposition pressure is 3.2Pa, substrate bias voltage is -60V, target current is 160A, Cr 0.30 Al 0.70 The thickness of each N nanolayer and NbN nanolayer is 7nm, that is, the adjacent Cr 0.30 Al 0.70 The sum of the thickness of the N nanolayer and the NbN nanolayer is 14 nm, and the thickness of the nanocomposite multilayer coating 2 is 3.5 μm;

[0048] In this embodiment, the deposition atmosphere is N 2 The following other embodiments are the same as this embodiment unless otherwise specified.

[0049] Example 2

[0050] A cutting tool containing a nanocomposite multilayer coating and a preparation method thereof of the present invention is basically the same as Example 1, except that the transition layer in Example 2 is Ti 0.50 Al 0.5 N, and the rest of the parameters are the same.

[0051] Example 3

[0052] A cutting tool containing a nanocomposite multilayer coating and a preparation method thereof of the present invention is basically the same as Example 1, except that: the Cr in the nanocomposite multilayer coating 2 in Example 3 0.30 Al 0.70 The thicknesses of the N nanolayer and the NbN nanolayer are 30 nm and 20 nm, respectively.

[0053] Example 4

[0054] A cutting tool containing a nanocomposite multilayer coating and a preparation method thereof of the present invention is basically the same as Example 1, except that: the Cr in the nanocomposite multilayer coating 2 in Example 4 0.30 Al 0.70 The thicknesses of the N nanolayer and the NbN nanolayer are 220 nm and 280 nm, respectively.

[0055] Example 5

[0056] A cutting tool containing a nanocomposite multilayer coating and a preparation method thereof of the present invention is basically the same as Example 1, except that: the Cr in the nanocomposite multilayer coating 2 in Example 5 0.30 Al 0.70 The N nanolayer consists of Cr 0.39 Al 0.60 Y 0.01 N nanolayers are substituted, and the rest of the parameters remain the same.

[0057] Example 6

[0058] A cutting tool containing a nanocomposite multilayer coating and a preparation method thereof of the present invention is basically the same as that of Example 1, except that: I c-NbN(111) / I h-NbN(100) =1.0.

[0059] Example 7

[0060] A cutting tool containing a nanocomposite multilayer coating and a preparation method thereof of the present invention is basically the same as that of Example 1, except that: I c-NbN(111) / I h-NbN(100) =0.1.

[0061] The tool substrate and model of reference product 1 are the same as those of Example 1. Ti is deposited by physical vapor deposition method. 0.40 Al 0.60 N / Cr 0.30 Al 0.70 N coating, coating thickness is 3.5μm.

[0062] The tool base and model of reference product 2 are the same as those of Example 1. The difference between the preparation process and Example 1 is that the transition layer is changed to Ti 0.50 Al 0.50N, the middle layer becomes Ti 0.50 Al 0.50 N / NbN nano-multilayer, the thickness of each layer is consistent with that in Example 1.

[0063] The tool substrate and model of reference product 3 are the same as those of Example 1. The difference between the preparation process and Example 1 is that the hexagonal structure of the NbN nanolayer presents a (100) preferred orientation, and the orientation factor τ h(100) =1.1.

[0064] The comparative experimental results of continuous turning of stainless steel (1Cr18Ni8Ti) of Examples 1 to 7 and Reference Products 1 to 3 are shown in Table 1 below:

[0065] Table 1 Comparative experimental results of turning stainless steel of the products of Examples 1 to 7 and the reference products 1 to 3

[0066]

[0067] The above results show that, under the same tool substrate and cutting conditions, the nanocomposite multilayer coating tool of the present invention has greatly improved the service life of the coated tool compared with the control example. The scrapping criteria for the turning test tools are all the maximum wear of the back tool face VB = 0.3mm. The failure process of the tool of the present invention is uniform wear failure, and no obvious crescent wear morphology is found on the front tool face. For turning processing, the final wear of the tools in Examples 1-5 is approximately 0.28mm, 0.30mm, 0.32mm, 0.29mm and 0.33mm respectively. The I of the coating of Examples 6-7 c-NbN (111) / I h-NbN(100) It is not within the optimal range. Too little cubic NbN ratio will affect the interfacial bonding strength of the coating to a certain extent, and the toughness will be reduced. Too much cubic NbN ratio will cause the coating hardness to be reduced and the wear resistance to be reduced, but it is still better than the existing technology. The wear of the reference product 1 after 9 minutes of processing has reached 0.92mm (the tip of the tool partly falls off), which is mainly related to its poor oxidation resistance and diffusion wear resistance. The wear of the back face of the reference product 2 after 12 minutes of processing reached ~0.60mm, and obvious crescent wear appeared on the front face. This is mainly because the thermal insulation effect of the coating of the reference product 2 is weak, and the heat taken away by the chips is limited, resulting in excessively high temperature in the cutting area. Under high temperature conditions, the phase change process of the TiAlN layer causes the heat resistance of the coating to decrease. When the chips quickly pass through the front face of the tool, the diffusion effect between the processed material and the coating material is intensified, and then a pit-shaped crescent wear is formed on the front face of the tool, destroying the integrity of the tool. The orientation factor of the coating of reference product 3 is relatively low, which will reduce the hardness of the NbN layer and lead to reduced wear resistance. After 13 minutes of processing, the wear amount reaches about 0.5 mm, and the failure form is uniform wear.

[0068] Example 8

[0069] A cutting tool containing a nanocomposite multilayer coating of the present invention, such as Figure 1 As shown, the tool substrate 3 and the nanocomposite multilayer coating 2 deposited on the tool substrate 3 are made of Cr 1-a-b Al a Me b The N layer 21 and the NbN layer 22 are alternately deposited to form Cr 1-a-b Al a Me b N / NbN periodic nano multilayer coating, wherein Me is Si, a=0.45, b=0.05, Cr 0.50 Al 0.45 Si 0.05 The single layer thickness of the N nanolayer is 15 nm, the single layer thickness of the NbN nanolayer is 10 nm, and the thickness of the nanocomposite multilayer coating 2 is 3.6 μm. 0.50 Al 0.45 Si 0.05 The N nanolayer is a face-centered cubic structure, and the NbN nanolayer is a mixed structure of cubic NbN and hexagonal NbN. The hexagonal NbN in the NbN nanolayer presents a (100) preferred orientation, and the orientation factor τ h(100) =3.1,I c-NbN(111) / I h-NbN(100) =0.52.

[0070] In this embodiment, a transition layer 1 is provided between the nano-composite multi-layer coating 2 and the tool substrate 3. The filter layer 1 is Cr 1- x Al x N layer, where x = 0.50, Cr 0.50 Al 0.50 The thickness of N layer is 0.40 μm, and the transition layer Cr 0.50 Al 0.50 The N layer has a face-centered cubic structure.

[0071] In this embodiment, the Cr in the nanocomposite multilayer coating 2 0.50 Al 0.45 Si 0.05 The N nanolayer is below the NbN nanolayer, but is not limited thereto. The Cr 0.50 Al 0.45 Si 0.05 The N nanolayer and the NbN nanolayer may be equal, for example, the NbN nanolayer may be 0.50 Al 0.45 Si 0.05 Below N.

[0072] In this embodiment, the cutting tool is a cemented carbide indexable insert, and the insert model is CNMG120408.

[0073] A method for preparing a cutting tool containing a nanocomposite multilayer coating according to the present embodiment comprises the following steps:

[0074] S1: Use a CNMG120408 carbide blade as the tool base, and pre-clean the tool base, including surface sandblasting and ultrasonic cleaning;

[0075] S2: performing Ar ion etching on the pretreated tool substrate;

[0076] S3: After Ar ion etching, the transition layer Cr is first deposited on the surface of the tool substrate using the PVD method. 0.50 Al 0.50 N layer, deposition temperature is 500℃, deposition pressure is 3.2Pa, substrate bias is -60V, target current is 180A, Cr 0.50 Al 0.50 The thickness of the N layer is 0.40 μm;

[0077] S4: Alternately deposit Cr on top of transition layer 1 0.50 Al 0.45 Si 0.05 N nanolayer and NbN nanolayer, forming Cr 0.50 Al 0.45 Si 0.05 N / NbN nanocomposite multilayer coating, deposition temperature is 500℃, deposition pressure is 4.8Pa, substrate bias is -100V, CrAlSi target and Nb target current are 180A and 200A, Cr 0.50 Al 0.45 Si 0.05 The thicknesses of the N nanolayer and the NbN nanolayer are 15 nm and 10 nm, respectively. 0.50 Al 0.45 Si 0.05 The sum of the thicknesses of the N nanolayer and the NbN nanolayer is 25 nm, and the thickness of the nanocomposite multilayer coating 2 is 3.6 μm.

[0078] Example 9

[0079] A cutting tool containing a nanocomposite multilayer coating and a preparation method thereof according to the present invention is substantially the same as that in Example 8, except that: in Example 9, the nanocomposite multilayer coating 2 is composed of alternately deposited Cr 0.35 Al 0.50 Ta 0.15 The nanostructured carbon nanotubes are composed of N nanolayers and NbN nanolayers.

[0080] Example 10

[0081] A cutting tool containing a nanocomposite multilayer coating and a preparation method thereof according to the present invention are substantially the same as those in Example 8, except that: in Example 10, the nanocomposite multilayer coating 2 is composed of alternately deposited Cr 0.35 Al 0.60 B 0.05 The nanostructured carbon nanotubes are composed of N nanolayers and NbN nanolayers.

[0082] The tool substrate and model of reference product 4 are the same as those of Example 8, and the preparation method is basically the same as that of Example 8, except that: the nanocomposite multilayer coating 2 in reference product 4 is composed of alternately deposited Cr 0.25 Al 0.50 Si 0.25 N nanolayer and NbN nanolayer, Cr 0.25 Al 0.50 Si 0.25 N is a mixed structure of hexagonal close-packed / face-centered cubic.

[0083] The tool base and model of reference product 5 are the same as those of Example 8. Cr is deposited by physical vapor deposition method. 0.50 Al 0.45 Si 0.05 N coating, coating thickness is 4.0μm.

[0084] The tool base and model of reference product 6 are the same as those of Example 8. Cr is deposited by physical vapor deposition method. 0.35 Al 0.50 Ta 0.15 N coating, coating thickness is 4.0μm.

[0085] The tool base and model of reference product 7 are the same as those of Example 8. Cr is deposited by physical vapor deposition method. 0.35 Al 0.60 B 0.05 N coating, coating thickness is 4.0μm.

[0086] The comparative experimental results of continuous turning of stainless steel (1Cr18Ni8Ti) by Examples 8 to 10 of the present invention and Reference Samples 4 to 7 are shown in Table 2 below:

[0087] Table 2 Comparative experimental results of turning stainless steel of the products of Examples 8 to 10 and the reference products 4 to 7

[0088]

[0089] The above results show that, under the same tool substrate and cutting conditions, the nanocomposite multilayer coating tool of the present invention has greatly improved the service life of the coated tool compared with the control example. After processing for 31 minutes, 32 minutes and 33 minutes respectively, the wear of the tool back face of Examples 8-10 was about 0.31mm, 0.32mm and 0.29mm, all of which were normal wear, and no obvious crescent wear morphology was found on the front face. After processing for 10 minutes, the control sample 4 showed severe wear, with the maximum wear value of the back face being about 1.4mm, and there was a sticky chip phenomenon near the cutting edge, which was mainly due to the Cr 0.25 Al 0.50 Si 0.25 The Si content in the N nanolayer exceeds the optimal value, and the Cr 0.25 Al 0.50 Si 0.25 The presence of more harmful hexagonal phases in N significantly reduced the hardness of the coating and increased the friction coefficient of the coating, which in turn led to reduced wear resistance and chipping. After processing for 14 minutes, 12 minutes, and 15 minutes respectively, the tool tips of the reference products 5, 6, and 7 all showed micro-collapse and tool tip burns, with the maximum values ​​of micro-collapse reaching 0.82mm, 1.1mm, and 0.95mm, respectively, and the front cutting surface showed different degrees of crescent wear morphology. The micro-collapse of the tool tip of the reference product is mainly due to Cr 0.50 Al 0.45 Si 0.05 N, Cr 0.35 Al 0.50 Ta 0.15 N and Cr 0.35 Al 0.60 B 0.05 The stress of N coating is large, and the toughness of coating is reduced. Under the action of high pressure, the hard points in the processed material cause the impact of the tool tip. The tool tip burn and the crescent wear morphology of the front tool face can be attributed to the Cr 0.50 Al 0.45 Si 0.05 N, Cr 0.35 Al 0.50 Ta 0.15 N and Cr 0.35 Al 0.60 B 0.05 The heat resistance of the N coating is slightly poor, which is caused by the decomposition of the coating material in a high temperature environment or a diffusion reaction between the coating material and the processed material.

[0090] The above is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as above in the preferred embodiment, it is not used to limit the present invention. Any technician familiar with the art can make many possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and technical solution of the present invention, or modify it into an equivalent embodiment of 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 invention without departing from the content of the technical solution of the present invention, still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A cutting tool containing a nanocomposite multilayer coating, characterized in that: The invention comprises a tool substrate and a nano-composite multi-layer coating deposited on the surface of the tool substrate, wherein the nano-composite multi-layer coating comprises Cr deposited alternately 1-a-b Al a Me b N layer and NbN layer, the Me element is at least one of Ti, Zr, Hf, V, Nb, Ta, Ru, Si, B, Y and W, wherein 0.3≤a≤0.7, 0<b≤0.2, the Cr 1-a-b Al a Me b The N layer is a face-centered cubic structure, and the NbN layer is a mixed structure of cubic NbN and hexagonal NbN, wherein the hexagonal NbN presents a (100) preferred orientation, and the orientation factor is 1.2≤τ h(100) ≤3.5; The (111) diffraction peak intensity of cubic NbN in the NbN layer is c-NbN(111) The (100) diffraction peak intensity I of hexagonal NbN h-NbN(100) The ratio is 0.2≤I c-NbN(111) / I h-NbN(100) ≤0.

6.

2. The cutting tool containing nanocomposite multilayer coating according to claim 1, characterized in that: The Cr 1-a- b Al a Me b The single layer thickness of the N layer is 2nm-300nm, and the single layer thickness of the NbN layer is 2nm-300nm.

3. The cutting tool containing nanocomposite multilayer coating according to claim 2, characterized in that: The thickness of the nano composite multi-layer coating is 0.5 μm to 8.0 μm.

4. The cutting tool containing nanocomposite multilayer coating according to claim 1, characterized in that: The nanocomposite multilayer coating is based on "Cr 1-a-b Al a Me b "N layer to NbN layer" is a cycle.

5. The cutting tool containing a nanocomposite multilayer coating according to any one of claims 1 to 4, characterized in that: A transition layer is provided between the nano-composite multi-layer coating and the tool substrate.

6. The cutting tool with nanocomposite multilayer coating according to claim 5, characterized in that: The transition layer is Cr 1-x Al x N layers, 0≤x≤0.7; or, the transition layer is Ti 1-y Al y N layers, 0≤y≤0.

6.

7. The cutting tool with nanocomposite multi-layer coating according to claim 5, characterized in that: The transition layer is a face-centered cubic structure, and the thickness of the transition layer is 0.1 μm to 2.0 μm.

8. The cutting tool containing nanocomposite multi-layer coating according to claim 6 or 7, characterized in that: The total coating thickness of the tool is 0.6 μm to 10.0 μm.

9. The cutting tool containing a nanocomposite multilayer coating according to any one of claims 1 to 4, characterized in that: The material of the tool matrix is ​​cemented carbide, metal ceramic, high-speed steel or cubic boron nitride sintered body.

10. A method for preparing a cutting tool containing a nanocomposite multilayer coating according to any one of claims 5 to 9, characterized in that: The following steps are involved: S1. Pre-treating the surface of the cutting tool substrate, wherein the pre-treatment includes sandblasting and ultrasonic cleaning; S2, ion etching the pretreated cutting tool substrate to further clean the surface; S3, using PVD method to deposit transition layer CrAl target or TiAl target on the surface of cutting tool substrate 1-x Al x N layer or Ti 1-y Al y N layer, deposition temperature is 400℃~600℃, deposition gas pressure is 1.0Pa~6.0Pa, substrate bias is -30V~-120V, CrAl or TiAl target current is 130A~200A; S4, using PVD method to deposit CrAlMe target and Nb target alternately on the transition layer 1-a-b Al a Me b N nanolayer and NbN nanolayer, forming Cr 1-a-b Al a Me b The N / NbN nanocomposite multilayer coating has a deposition temperature of 400°C to 600°C, a deposition gas pressure of 1.0Pa to 6.0Pa, a substrate bias of -30V to -120V, and currents of the CrAlMe target and the Nb target are 130A to 200A and 150A to 200A, respectively.

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