CN114592166A

CN114592166A - Hard coating cutter containing gradient composite structure and preparation method thereof

Info

Publication number: CN114592166A
Application number: CN202210259400.9A
Authority: CN
Inventors: 裴斐; 陈响明; 温光华; 汤爱民; 罗胜; 罗学全
Original assignee: Zhuzhou Cemented Carbide Cutting Tools Co Ltd
Current assignee: Zhuzhou Cemented Carbide Cutting Tools Co Ltd
Priority date: 2022-03-16
Filing date: 2022-03-16
Publication date: 2022-06-07
Anticipated expiration: 2042-03-16
Also published as: CN114592166B

Abstract

The invention discloses a hard coating cutter containing a gradient composite structure and a preparation method thereof, wherein the cutter comprises a cutter substrate and a hard coating, the hard coating comprises a multilayer coating of the gradient composite structure and a functional layer TiB arranged on the surface of the multilayer coating₂The multilayer coating comprising alternately deposited Ti_1‑xAl_xN-and TiBN-layers, Ti_1‑xAl_xThe thickness of the N layer decreases with increasing distance from the tool base, and the thickness of the TiBN layer increases with increasing distance from the tool base. The preparation method comprises the steps of depositing an interface layer and a supporting layer on a pretreated cutter base body, and then alternately depositing Ti_1‑xAl_xN-layer and TiBN-layer, redepositing functional layer. The hard coating cutter has the advantages of low stress, high strength and toughness, high film-substrate bonding strength, excellent wear resistance, high heat resistance and the like, and can expand TiB₂The application range of the base coating, the preparation method and the process are simple, and the production cost is low.

Description

Hard coating cutter containing gradient composite structure and preparation method thereof

Technical Field

The invention relates to the technical field of coatings of cutting tools, in particular to a hard coating tool containing a gradient composite structure and a preparation method thereof.

Background

The first generation of hard coating TiN was successfully applied in the field of cutting tools in the 70 th 20 th century, which is another important revolution in the field of cutting machining after the invention of cemented carbide. The hard coating on the surface of the cutter can obviously improve the wear resistance and high-temperature use performance of the cutter, and the boosting cutting process is changed to high-speed and high-efficiency dry green processing. With the rapid development of coating technology, TiAlN, CrAlN, TiAlSiN, CrAlSiN and multilayer coatings thereof become coating materials which are widely applied at present by virtue of good mechanical property, oxidation resistance and thermal stability. However, with the rapid development of modern manufacturing industry, the application of difficult-to-machine materials such as various novel high-temperature alloys and high-performance stainless steels is increasing, and more severe requirements are put forward on the coating performance of cutting tools, for example, severe work hardening phenomenon occurs in the process of machining high-temperature alloys and stainless steels, which aggravates tool wear, and in addition, in order to improve the performance of materials such as high-temperature alloys and stainless steels, various other elements are often added in the materials, and the materials are easily subjected to chemical reaction with TiAlN-based or CrAlN-based coatings under the action of cutting heat, so that crescent crater wear is generated on the rake face of the cutting tool too early, and the cutting tool is rapidly disabled. Meanwhile, the difficult-to-machine materials such as high-temperature alloy and stainless steel have another characteristic of low thermal conductivity, cutting heat is not easy to be taken away by cutting chips, but is mainly concentrated in a cutting area, and the requirement for higher heat resistance of a cutter coating is met. Therefore, the conventional nitride coating has been difficult to satisfy the requirements for efficient and high-precision processing of the above materials.

TiB₂Is C32 type hexagonal crystal structure, belongs to transition metal boride, and is boronAnd the most stable compound of titanium, the boron atom surface and the titanium atom surface in the crystal structure alternate with each other to form a two-dimensional network structure, and the boron atom and the titanium atom are combined through covalent bonds, so that the TiB is determined₂Is a chemically very stable substance and has very high hardness and wear resistance, second only to diamond and cubic boron nitride. TiB₂Can be kept stable in high-temperature environment, does not generate phase change and has higher thermal stability. Thus, TiB₂The coating has great application prospect in the field of hard wear resistance. However, currently TiB₂Coated tools have only a few applications in the field of non-ferrous metal machining and partial titanium alloy machining, and very few applications in the field of difficult-to-machine materials such as stainless steel, superalloys, etc., mainly because although TiB is a rare earth metal, it is also very difficult to machine₂The coating has a plurality of excellent properties, but simultaneously has the defects of poor toughness, large residual stress, low bonding strength of a coating film base and the like, and limits TiB to a certain extent₂The practical application range of (1).

Chinese patent document CN108165943A discloses a TiB with a structural gradient₂The coating preparation method adjusts TiB by adjusting the duty ratio output by the bipolar pulse bias power supply₂The stress of the layer is used to reduce the internal stress of the coating and improve the adhesive force of the film base. However, in practice, a limited reduction in coating stress is found, and, due to the cemented carbide substrate and TiB₂The inherent difference between the coefficient of thermal expansion and the bulk modulus of elasticity of the coating results in a high residual stress at the film-substrate interface, which is prone to premature failure during machining.

Chinese patent document CN101886242A discloses a titanium boride/silicon nitride nano multilayer coating and a preparation method thereof, wherein Si₃N₄The thickness of the layer is 0.2-0.8nm, TiB₂The thickness of the layer is 2-8nm, Si₃N₄Layer and TiB₂With coherent epitaxial growth structure between the layers, Si₃N₄/TiB₂The hardness of the nano multilayer coating is higher than 37GPa, and the oxidation resistance temperature is raised to 800 ℃. The coating produced in this patent document has a high hardness, but because of Si₃N₄And TiB₂The coating belongs to a coating with larger stress, the stress of the superlattice coating formed by compounding the coating and the coating is obviously larger, so that the bonding strength of a film substrate is reduced, and the coating is fallen off from a hard alloy substrate when the high hardness of the coating does not play a role of wear resistance.

Chinese patent documents CN107190241A and CN110042343A disclose TiB having a periodic structure₂Base coating and method for its preparation by alternate deposition of TiB₂The nano multilayer coating formed by periodically and mutually overlapping certain metals (such as Cr, Al and W) has lower residual stress, however, the hardness of the nano multilayer coating is greatly reduced to about 30GPa, and the pure metal layer in the nano multilayer coating not only reduces the wear resistance in cutting, but also diffuses with the processed material (particularly difficult-to-process material) to further increase the wear degree of a cutter, so that the technology is not suitable for modifying the surface of a cutting tool.

Chinese patent document CN101214744A discloses a radio frequency magnetron sputtering method for preparing superhard TiB₂The TiAlN nano multilayer film is characterized in that a multilayer coating with the period of 25nm is deposited on a pure Ti metal priming layer, the hardness of the coating reaches 36GPa, the internal stress is 3.4GPa, and the bonding strength of a film substrate is improved. CN107190243A discloses a TiB₂The AlTiN composite coating adopts AlTiN layers and TiB layers which are alternately deposited as well as a preparation method and application thereof₂And the multilayer coating with the modulation period of 100nm-1000nm is prepared, so that the toughness and the oxidation resistance of the coating are improved. However, the method is not tested in practical application, and the deposition rate of the radio frequency magnetron sputtering method is very low, so that the method is not suitable for large-scale industrial production at present. The TiAlN layer in the nano multilayer is decomposed at about 900 ℃ to form a softening phase w-AlN, the integrity of the coating is damaged by the thermal decomposition and the phase change, so that the wear resistance of the coating is reduced, and particularly, when difficult-to-process materials such as stainless steel, high-temperature alloy and the like are processed, the decomposition and the phase change process of the coating are aggravated by cutting heat, and the performance is reduced.

In summary, TiB prepared by physical vapor deposition in the above patent documents₂Gradient coating or TiB₂Multilayer coating, to a certain extent promote TiB₂Properties of the coating, however, the above-mentioned TiB-containing₂The coating still has the defects of low film-substrate bonding strength, overlarge coating stress, low wear resistance and the like, and TiB is used in severe service environment with heavy tool load, such as efficient processing of materials difficult to process, such as high-temperature alloy, stainless steel and the like₂The phenomena of large coating stress, poor film-substrate bonding strength, insufficient wear resistance or low heat resistance and the like still cause the cutter to fail prematurely, thereby seriously limiting TiB₂The application range of the coating.

Disclosure of Invention

The technical problem to be solved by the invention is to overcome the defects of the prior art, in particular to the prior TiB₂The defects of over-high stress, weak film-substrate bonding strength, poor heat resistance and the like of the base coating layer provide a coating layer which has low stress, high obdurability, high film-substrate bonding strength, excellent wear resistance and high heat resistance and can expand TiB₂A hard coating cutter containing a gradient composite structure in the application range of a base coating and a preparation method thereof.

In order to solve the technical problems, the invention adopts the following technical scheme.

The hard coating cutter containing the gradient composite structure is characterized by comprising a cutter base body and a hard coating deposited on the cutter base body, wherein the hard coating comprises a gradient composite structure multilayer coating and a functional layer arranged on the surface of the gradient composite structure multilayer coating, and the functional layer is TiB₂Layers, the gradient composite structure multilayer coating comprising alternately deposited Ti_1-xAl_xN layer and TiBN layer, the Ti_1-xAl_xX in the N layer is more than or equal to 0.3 and less than or equal to 0.7, and the Ti_1-xAl_xThe thickness of the N layer is controlled to be 20 nm-500 nm, the thickness of the TiBN layer is controlled to be 10 nm-500 nm, and the Ti_1-xAl_xThe thickness of the N layer is reduced along with the increase of the distance from the tool base body, the thickness of the TiBN layer is increased along with the increase of the distance from the tool base body, and the gradient composite structure multilayer coating at least comprises two periods of alternate deposition.

The above-mentioned hard coating tool having a gradient composite structure is preferableSaid Ti_1-xAl_xThe thickness of the N layer is controlled to be 40 nm-400 nm, and the thickness of the TiBN layer is controlled to be 20 nm-300 nm.

Preferably, the above hard coating tool having a gradient composite structure is the Ti_1-xAl_xThe N layer is a single-phase cubic structure, and the TiBN layer is formed by wrapping nano TiN crystal grains and nano TiB with amorphous BN₂A nanocomposite structure of grains.

Preferably, the above hard coating tool having a gradient composite structure is the Ti_1-xAl_xIn the N layer, x is more than or equal to 0.4 and less than or equal to 0.6.

Preferably, the gradient composite structure multi-layer coating is Ti_1-xAl_xThe N layer to the TiBN layer' is a cycle period, and the first layer of the gradient composite structure multilayer coating is Ti_1- _xAl_xN layers and the last layer are TiBN layers, the thicknesses of any two adjacent circulation periods are different, and the thicknesses of the circulation periods tend to decrease from the direction close to the cutter base body to the direction far away from the cutter base body.

Preferably, the total thickness of the gradient composite structure multilayer coating is 500nm to 3000 nm.

In the hard coating cutter with the gradient composite structure, the thickness of the functional layer is preferably 500nm to 3000nm, and more preferably 800nm to 1500 nm.

Preferably, the hard coating layer of the above hard coating tool with a gradient composite structure further comprises a support layer, the support layer is arranged between the multilayer coating layer with the gradient composite structure and the tool base body, and the support layer is Ti_1-yAl_yN layer, y is more than or equal to 0.3 and less than or equal to 0.7, and the Ti_1-yAl_yN layer and the Ti_1-xAl_xThe components and the structures of the N layers are the same, the thickness of the supporting layer is 500 nm-3000 nm, and the thickness of the supporting layer is more preferably 800 nm-1800 nm.

Preferably, the hard coating layer of the hard coating tool with the gradient composite structure further comprises interfacial adhesionA layer, the interfacial adhesion layer being disposed between the support layer and the cutter base, the interfacial adhesion layer being Ti_1-aAl_aAnd a is more than or equal to 0 and less than or equal to 0.7, the thickness of the interface bonding layer is 50nm to 1000nm, and the thickness of the interface bonding layer is more preferably 100nm to 500 nm.

Preferably, the above hard coating tool having a gradient composite structure is the Ti_1-aAl_aIn the N layer, a is more than or equal to 0 and less than or equal to 0.6.

Preferably, the above hard coating tool having a gradient composite structure is the Ti_1-aAl_aThe N layer is of a cubic structure.

Preferably, the total thickness of the hard coating is 1500 nm-10000 nm.

As a general technical concept, the present invention also provides a method for preparing the above hard coating cutter including the gradient composite structure, comprising the steps of:

s1, depositing an interface bonding layer: depositing an interface bonding layer on the pretreated cutter substrate by adopting a non-equilibrium magnetron sputtering method;

s2, deposition of a support layer: depositing a supporting layer on the interface bonding layer by adopting a non-equilibrium magnetron sputtering method;

s3, depositing a gradient composite structure multilayer coating: alternately depositing Ti on the supporting layer by adopting an unbalanced magnetron sputtering method_1-xAl_xN layer and TiBN layer, the deposition conditions are as follows: introducing argon gas flow of 300-340 sccm, nitrogen gas flow of 100-120 sccm, controlling pressure to be 0.60-0.70 Pa, bias voltage to be-100V-150V, deposition temperature to be 400-500 ℃, and depositing Ti_1-xAl_xStarting a TiAl target power supply during the N layer, gradually reducing the power of the TiAl target from 18kW to 8kW within the discharge time period of the corresponding period according to the difference of the cycle period number, closing the TiAl target power supply and starting a TiB when the TiBN layer is deposited₂Target power supply, TiB depending on the number of cycles₂The power of the target was gradually increased from 3kW to 10kW during the discharge period of the corresponding cycle, or when Ti was deposited_1-xAl_xFixing TiAl target for N layer and TiBN layerThe power of the power is 10kW to 15kW, TiB₂The power of the target is 4 kW-5 kW, and TiB is closed alternately₂Target, turn on TiAl target or turn on TiB₂Target, TiAl target turned off to deposit the corresponding Ti_1-xAl_xThe N layer and the TiBN layer gradually reduce the discharge time of the TiAl target in corresponding periods and prolong TiB according to different cycle periods₂Discharge time of target, Ti deposition by alternation_1-xAl_xObtaining a gradient composite structure multilayer coating after N layers and TiBN layers;

s4, depositing a functional layer: and depositing a functional layer on the multilayer coating with the gradient composite structure to obtain the hard coating cutter with the gradient composite structure.

In the above method for preparing a hard coated cutting tool with a gradient composite structure, preferably, in step S1, the deposition conditions of the interfacial adhesion layer are as follows: introducing argon and nitrogen, wherein the flow of the argon is 220 sccm-260 sccm, the flow of the nitrogen is 80 sccm-100 sccm, the pressure is controlled by the nitrogen to be kept at 0.40 Pa-0.50 Pa, the power of the TiAl target is controlled to be 5 kW-8 kW, the bias voltage is-50V-80V, and the deposition temperature is 400-500 ℃.

In the above method for preparing a hard coated cutting tool with a gradient composite structure, preferably, in step S2, the deposition conditions of the supporting layer are as follows: controlling the flow of argon gas to be 220 sccm-260 sccm, the flow of nitrogen gas to be 100 sccm-120 sccm, controlling the pressure to be 0.50 Pa-0.60 Pa by nitrogen gas, controlling the power of the TiAl target to be 10 kW-15 kW, controlling the bias voltage to be-80V-100V, and controlling the deposition temperature to be 400-500 ℃.

Preferably, in the step S4, the deposition process of the functional layer is as follows: closing the TiAl target power supply, stopping introducing nitrogen, increasing the argon flow to 400-500 sccm, controlling the pressure in the chamber to be 0.60-0.70 Pa, and TiB₂Adjusting the power of a target power supply to 4 kW-5 kW, and beginning to deposit TiB₂And (3) depositing the layer at the temperature of 400-500 ℃ under the bias voltage of-80V-150V, turning off the power supply after the deposition is finished, and taking out the product after the indoor temperature is cooled to be below 100 ℃.

The preparation method of the hard coating cutter containing the gradient composite structure is preferableAnd in step S1, the pretreatment of the tool base includes surface blasting, ultrasonic cleaning, and ion etching cleaning, and the ion etching cleaning process includes: starting an ion source, introducing 200-300 sccm argon gas into the ion source, setting the power of the ion source to be 1.5kW, the bias voltage to be-500V-800V, and the etching cleaning time to be 20-35 min. Before the interfacial adhesion layer is deposited, the reaction chamber of the deposition equipment is preferably vacuumized to 5.0 x 10^-3Pa below, and the temperature is controlled to be 400-500 ℃.

In the present invention, Ti is alternately deposited_1-xAl_xThe N layer and the TiBN layer form a gradient composite structure multilayer coating with aperiodic thickness, the gradient composite structure multilayer coating can effectively connect a supporting layer (or a cutter substrate) and a functional layer, the internal stress of the coating is reduced, and the toughness of the coating is optimized.

In the present invention, Ti in the gradient composite structure multilayer coating_1-xAl_xThe thickness of the N layer is 20 nm-500 nm, the thickness of the TiBN layer is 10 nm-500 nm, and Ti_1-xAl_xThe thickness of the N layer is less than 20nm, the oxidation resistance of the multilayer coating can be reduced, the thickness of the N layer is more than 500nm, the hardness of the multilayer coating can be reduced, the thickness of the TiBN layer is less than 10nm, the hardness of the multilayer coating can be reduced, the friction coefficient of the coating is increased, the thickness of the TiBN layer is more than 500nm, the stress of the coating is increased, and the toughness is reduced.

In the present invention, the hardness of the non-periodic thickness gradient composite structure multilayer coating is preferably 33 to 35GPa and higher than Ti_1-xAl_xHardness of N layer lower than that of the outermost layer of TiB₂The hardness of the layer.

In the present invention, the gradient composite structure multilayer coating comprises at least two cycles of alternate deposition, i.e., the number of cycle cycles is not less than 2, and more preferably not less than 3.

According to the invention, the direction from inside to outside (or from bottom to top) is from the surface of the cutter substrate to the outside, the supporting layer is arranged below the gradient composite structure multilayer coating, and the functional layer is arranged above the gradient composite structure multilayer coating, so that the stress of the TiBN layer can be reduced, and the component mutation of the gradient composite structure multilayer coating and the functional layer can be relieved, thereby being beneficial to improving the bonding strength between the coatings.

In the invention, the support layer and Ti in the gradient composite structure multilayer coating_1-xAl_xThe N composition and structure are the same, helping to coordinate the stress distribution in the coating.

In the invention, the thickness of the supporting layer is 500-3000 nm, preferably 800-1800 nm, too thin thickness can not play a supporting role, and too thick thickness can increase the stress of the coating and reduce the toughness and bonding strength of the coating.

In the present invention, the functional layer TiB₂Is 500nm to 3000nm, preferably 800nm to 1500nm, too thin reduces wear resistance, and too thick increases stress of the coating, causing delamination or peeling of the coating.

In the present invention, the interfacial adhesion layer may be bonded to the support layer (Ti)_1-xAl_xN) has the same composition and structure.

In the present invention, the thickness of the interfacial adhesion layer is 50nm to 1000nm, preferably 100nm to 500nm, and too thin thickness affects film-based bonding strength, and too thick thickness causes stress increase.

In the invention, when the interface bonding layer is the same as the supporting layer, the thickness of the interface bonding layer is not separately considered, and only the thickness of the supporting layer is considered.

Compared with the prior art, the invention has the advantages that:

(1) due to TiB₂Inherent characteristics of the TiB, prepared under the conditions of the prior art₂The coating usually has the defects of over-high stress, poor film-substrate bonding strength and the like, and is only applied to cutting in the nonferrous technical field of aluminum alloy, copper alloy and the like. The hard coating containing the gradient composite structure overcomes the defects of the traditional TiB₂The hard coating has the defects of over-high stress, poor film-substrate bonding strength, easy occurrence of premature breakage failure and the like, improves the wear resistance of the coating, and enlarges the TiB₂The application range of the coating is wide, so that the coating has excellent cutting performance in the field of difficult-to-process materials such as stainless steel, heat-resistant cast steel and the like.

(2) The invention is based on Ti (Al)N and TiB₂TiAlN/TiBN multilayer gradient structure layers are arranged between the layers and can supply TiB₂The method has the advantages of providing stronger storage capacity, and simultaneously finding that the multilayer gradient structure layer can effectively reduce the internal stress of the hard coating, enhance the toughness of the hard coating and inhibit the propagation of cracks. Is different from the traditional TiB with a gradient structure₂The TiAlN/TiBN gradient composite structure multilayer coating introduced by the invention optimizes the thickness of a TiAlN layer and a TiBN layer and is added to an outermost functional layer (TiB)₂Wear-resistant layer), the thickness of the TiAlN layer is gradually thinned, the thickness of the TiBN layer is gradually thickened, the thickness of the TiAlN layer is gradually thickened and the thickness of the TiBN layer is gradually thinned towards the direction that the cutter substrate or the supporting layer (TiAlN) is close to, thus relieving the tissue and performance mutation between the outermost functional layer and the supporting layer (or the cutter substrate) and the multilayer gradient structure layer, and not only exerting the TiB₂The functional layer has high wear resistance and excellent chemical stability, and the bonding strength between the functional layer and the nitride layer is improved, so that the service life of the cutting tool is obviously prolonged.

(3) The preparation method of the hard coating cutter containing the gradient composite structure has the characteristics of simple process, low equipment requirement and low production cost, and can meet the requirement of high-speed processing on better performance of the cutter material.

In summary, in maintaining TiB₂The invention effectively improves the reliability and the wear resistance of the cutter product in the whole cutting process and expands TiB while having high hardness and low adhesion tendency₂The field of application of base coatings. The coated cutter is suitable for cemented carbide indexable inserts, is also suitable for cutting tool materials such as metal ceramics, non-metal ceramics, cubic boron nitride and the like, and is particularly suitable for cutting processing of difficult-to-process materials such as stainless steel, heat-resistant cast steel and the like and cutting processing of non-ferrous metal materials.

Drawings

FIG. 1 is a schematic structural diagram of a hard coated cutting tool comprising a gradient composite structure according to an embodiment of the present invention.

Illustration of the drawings:

10. a tool base; 20. interface (I)An adhesive layer; 30. a hard coating; 31. a support layer; 32. gradient composite structure multilayer coating; 321. a TiBN layer; 322. ti_1-xAl_xN layers; 33. and a functional layer.

Detailed Description

The invention is further described below with reference to the drawings and specific preferred embodiments of the description, without thereby limiting the scope of protection of the invention. The materials and instruments used in the following examples are commercially available unless otherwise specified.

Example 1

A hard coating cutter containing a gradient composite structure comprises a cutter base body 10 and a hard coating 30 deposited on the cutter base body 10, wherein the hard coating 30 comprises a gradient composite structure multilayer coating 32 (also referred to as the gradient layer 32 for short) and a functional layer 33 arranged on the surface of the gradient composite structure multilayer coating 32, and the functional layer 33 is TiB₂The layer, gradient composite structure multilayer coating 32 comprises alternately deposited Ti_1-xAl_xN layer 322 and TiBN layer 321, Ti_1-xAl_xX in N layer 322 is 0.6, i.e. Ti_0.40Al_0.60N layer of Ti_1-xAl_xThe thickness of the N layer 322 decreases with increasing distance from the tool base body 10, the thickness of the TiBN layer 321 increases with increasing distance from the tool base body 10, and the first layer of the gradient composite structure multilayer coating 32 is Ti_1- _xAl_xN layer 322, the last layer being TiBN layer 321, gradient composite multilayer coating 32 comprising three alternating deposition periods, i.e. Ti_0.40Al_0.60The number of N/TiBN modulation cycles is 3, the first cycle: ti_0.40Al_0.60The thickness of the N layer is 300nm, and the thickness of the TiBN layer 321 is 50 nm; second period: ti_0.40Al_0.60The thickness of the N layer is 200nm, and the thickness of the TiBN layer 321 is 100 nm; in the third period: ti_0.40Al_0.60The thickness of the N layer is 100nm, and the thickness of the TiBN layer is 150 nm.

In this example, Ti_1-xAl_xN layer 322 (i.e., Ti)_0.40Al_0.60N layer) is a single-phase cubic structure, and the TiBN layer 321 is formed by wrapping nano-sized TiN crystal grains and nano-sized TiB by amorphous BN₂Nanocomposite of grainsAnd (5) structure.

In this embodiment, the gradient composite structure multilayer coating 32 is "Ti_1-xAl_xThe thicknesses of any two adjacent circulation periods are different from each other, the thicknesses of the N layers 322 to the TiBN layer 321' are respectively a first period, a second period and a third period from the cutter base body 10 to the functional layer 33, and the thicknesses of the coatings of the first period, the second period and the third period are reduced in sequence.

In this example, the total thickness of the gradient composite structure multilayer coating 32 is 900 nm.

In this embodiment, the thickness of the functional layer 33 is 900 nm.

In this embodiment, the hard coating 30 further includes a supporting layer 31, the supporting layer 31 is disposed between the gradient composite structure multilayer coating 32 and the tool base 10, and the supporting layer 31 is Ti_0.40Al_0.60The N layer is of a single-phase cubic structure, and the thickness of the supporting layer 31 is 1300 nm.

In this embodiment, the hard coating 30 further includes an interface bonding layer 20, the interface bonding layer 20 is disposed between the supporting layer 31 and the tool base 10, and the interface bonding layer 20 is Ti_0.50Al_0.50The N layer is of a cubic structure, and the thickness of the interface bonding layer 20 is 250 nm.

In this example, the total thickness of the hard coat layer 30 was 3350 nm.

In this example, the tool base 10 was a ONMU060408-GM type cemented carbide milling insert with a Co content of 10 wt.%, the remainder being WC.

A method for preparing a hard coating cutter containing a gradient composite structure according to the embodiment comprises the following steps:

(1) powder raw materials (the content of Co is 10 wt.%, and the balance is WC) of specified components of the ONMU060408-GM type hard alloy milling blade are mixed, granulated, pressed and molded, sintered and a hard alloy blank is prepared, a primary cutter base body is prepared through subsequent grinding, the cutting edge of the cutter is passivated, certain strength of the cutting edge of the cutter is ensured, and sand blasting and ultrasonic cleaning are carried out on the cutting edge of the cutter, so that good surface quality is achieved. Before formal coating, argon ions are adopted to carry out ion bombardment etching on the surface of the cutter, the flow of the argon is 240sccm, the power of an ion source is 1.5kW, the bias voltage is-650V, and the etching time is 30min, so that the quality of the surface of the cutter is further improved, the bonding strength between the coating and the base body is favorably strengthened, and the cutter base body 10 is obtained.

(2) Deposition of the interfacial adhesion layer 20: target materials (Ti) of different compositions₅₀Al₅₀、Ti₄₀Al₆₀And TiB₂) Fixing the substrate at a corresponding cathode position, raising the temperature in the furnace to 450 ℃, controlling the flow rate of argon gas to 240sccm and the flow rate of nitrogen gas to 80sccm, controlling the pressure in the furnace to be 0.45Pa by using a non-equilibrium magnetron sputtering mode, controlling the power of the TiAl target material to be 6kW and biasing to 60V, and depositing an interface bonding layer 20, namely Ti on the pretreated cutter substrate 10_0.50Al_0.50And the thickness of the interface bonding layer is 250 nm.

(3) Deposition support layer 31: keeping the flow of argon and the deposition temperature unchanged, increasing the flow of nitrogen to 120sccm, controlling the pressure in the furnace to be 0.5Pa, the TiAl target power to be 10kW and the bias voltage to be-80V, and depositing to obtain the supporting layer 31, namely Ti_0.40Al_0.60And N layers, wherein the thickness of each layer is 1300 nm.

(4) Depositing a gradient composite structure multilayer coating 32: alternately depositing Ti on the support layer 31 while maintaining the deposition temperature_1-xAl_x An N layer 322 and a TiBN layer 321 formed of Ti_1-xAl_x The N layer 322 to the TiBN layer 321 are multi-layer coatings with a cycle period, in the multi-layer coating deposition, the flow of argon is 300sccm, the flow of nitrogen is 100sccm, the gas pressure in the furnace is 0.60Pa, the TiAl target power is fixed to be 14kW, and TiB₂The target power was fixed at 4.5kW and the bias was-100V. In the first period, the opening time of the TiAl target is 20min, then the TiAl target is closed, and the TiB is opened₂Discharging the target for 10 min; in the second period, the opening time of the TiAl target is 13.5min, then the TiAl target is closed, and the TiB is opened₂Discharging the target for 20 min; in the third period, the opening time of the TiAl target is 6.7min, then the TiAl target is closed, and the TiB is opened₂Discharging the target for 30 min; thus, Ti can be obtained_1-xAl_x The N layer 322 is gradually thinned, and the TiBN layer 321 is gradually increased, and the total thickness of the gradient composite structure multilayer coating 32 with non-periodic thickness is 900 nm.

(5) Deposition of the functional layer 33: the TiAl target power supply is turned off,holding TiB₂Power on state of target material, TiB₂Fixing the target power to 4.5kW, closing a nitrogen valve, stopping introducing nitrogen, increasing the argon flow to 450sccm, adjusting the pressure in the furnace to 0.65Pa, keeping the deposition temperature unchanged, and continuously depositing a functional layer 33, namely TiB, on the surface of the gradient composite structure multilayer coating 32₂Coating, the functional layer 33 has a thickness of 900 nm. And after the coating is finished, all target power supplies are closed, the temperature in the furnace is cooled to be below 100 ℃ in a vacuum environment, the furnace door is opened, and the coating cutter is taken out, so that the high-performance hard coating cutter containing the gradient composite structure can be obtained.

The control tool 1 was a cemented carbide milling insert of the same shape and same base composition as in example 1, the coating being a commercially available TiN-TiB₂The coating is prepared by adopting the same unbalanced magnetron sputtering method as the embodiment, the total thickness is 3400nm, TiN is taken as a bottom layer, and the thickness is 200 nm.

The control tool 2 was a cemented carbide milling insert of the same shape and same base composition as in example 1, the coating being commercially available TiB₂The single-layer coating was prepared by the same unbalanced magnetron sputtering method as in this example, and the coating thickness was 3350 nm.

The control tool 3 was a cemented carbide milling insert of the same shape and same base composition as in example 1, the coating being Ti produced by a cathodic arc method commonly used in the market_0.40Al_0.60N-Ti_0.50Al_0.40Si_0.10N double-layer structure coating, the inner layer is Ti_0.40Al_0.60N, the thickness ratio of the inner layer to the outer layer is 1.5: 1, and the total thickness of the coating is 3350 nm.

The tool of the present example was compared with three control tools according to the following machining conditions:

the processing material is UNS 31803;

the processing mode is rough milling of a flange surface;

the model of the cutter is FMA12-160-C40-ON 06-12;

cutting speed Vc is 71 m/min;

the cutting depth ap is 2 mm;

the cutting width ae is 63 mm;

feed fz of each tooth is 0.2 mm/z;

a cooling mode: air cooling;

the standard of the product life is that the flank damage Vb of the cutter exceeds 0.2 mm.

In the embodiment, 98 parts are machined by the cutter, and the normal back cutter face is abraded; the contrast cutter 1 is subjected to severe wear failure after 55 parts are processed; the contrast tool 2 is used for processing 58 tool tips which are broken and failed; the comparison tool 3 was subjected to severe plastic deformation and severe wear aging for 68 pieces. Under the condition, the service life of the cutter of the embodiment is improved by about 78 percent compared with that of the comparison cutter 1, about 69 percent compared with that of the comparison cutter 2 and about 44 percent compared with that of the comparison cutter 3.

The excellent properties of this example and its wear pattern are normal flank wear, thanks to the coating having better bond strength, lower residual stress, and excellent heat resistance and chemical stability. If the residual stress of the coating is too great, the tool surface coating will peel off prematurely, resulting in an increased reduction in the wear resistance of the tool and consequently in severe wear, as in the case of the control tool 1. If the bonding strength of the coating and the substrate interface is weak or the TiB₂The bonding strength between the layer and the nitride layer is poor, the residual stress is too large, under the action of high pressure and chip frictional heat, the coatings on the front and rear tool surfaces of the tool in the cutting area are prematurely peeled off, and abnormal failures such as tip burning or tip chipping easily occur in the cutting process, such as a comparison tool 2. The plastic deformation of the tool nose is generally caused by excessive cutting heat in the tool nose area, like the comparison tool 3, which is mainly caused by the large friction coefficient of the TiAlN-TiAlSiN coating deposited in a cathode arc mode and the generation of a large amount of cutting heat during the cutting processing UNS 31803.

Example 2

The hard coating cutter containing the gradient composite structure comprises a cutter base body 10 and a hard coating 30 deposited on the cutter base body 10, wherein the hard coating 30 comprises a gradient composite structure multilayer coating 32 and a functional layer 33 arranged on the surface of the gradient composite structure multilayer coating 32, and the functional layer 33 is TiB₂The layer, gradient composite structure multilayer coating 32 comprises alternately deposited Ti_1-xAl_xN layer 322 and TiBN layer 321, Ti_1-xAl_xX in N layer 322 is 0.6, i.e. Ti_0.40Al_0.60N layer of Ti_1-xAl_xThe thickness of the N layer 322 decreases with increasing distance from the tool base body 10, the thickness of the TiBN layer 321 increases with increasing distance from the tool base body 10, and the first layer of the gradient composite structure multilayer coating 32 is Ti_0.40Al_0.60N layers, the last layer being a TiBN layer 321, the gradient composite structure multilayer coating 32 comprising 5 cycles of alternate deposition, i.e. Ti_0.40Al_0.60The number of N/TiBN modulation cycles is 5, the first cycle: ti_0.40Al_0.60The thickness of the N layer is 350nm, the thickness of the TiBN layer 321 is 30nm, and the second period is as follows: ti_0.40Al_0.60The thickness of the N layer is 260nm, the thickness of the TiBN layer 321 is 60nm, and the third period: ti_0.40Al_0.60The thickness of the N layer is 200nm, the thickness of the TiBN layer 321 is 90nm, and the fourth period: ti (titanium)_0.40Al_0.60The thickness of the N layer is 100nm, the thickness of the TiBN layer 321 is 120nm, and the fifth period is as follows: ti_0.40Al_0.60The thickness of the N layer is 40nm, and the thickness of the TiBN layer 321 is 150 nm. The total thickness of the gradient composite structure multilayer coating 32 is 1400 nm.

In this example, Ti_1-xAl_x The N layer 322 is a single-phase cubic structure, and the TiBN layer 321 is amorphous BN coated with nanometer size TiN grains and nanometer size TiB₂A nanocomposite structure of grains.

In this embodiment, the gradient composite structure multilayer coating 32 is "Ti_1-xAl_x The N layer 322 to the TiBN layer 321 ″ are a cyclic period, and the thicknesses of any two adjacent cyclic periods are different.

In this embodiment, the functional layer 33 has a thickness of 1000 nm.

In this embodiment, the hard coating 30 further includes a supporting layer 31, the supporting layer 31 is disposed between the gradient composite structure multilayer coating 32 and the tool base 10, and the supporting layer 31 is Ti_0.40Al_0.60The N layer is of a single-phase cubic structure, and the thickness of the supporting layer 31 is 1200 nm.

In this embodiment, the hard coating 30 further includes an interface bonding layer 20, and the interface bonding layer 20 is disposed between the supporting layer 31 and the tool base body10, the interface adhesion layer 20 is Ti_0.50Al_0.50The N layer is of a cubic structure, and the thickness of the interfacial adhesion layer 20 is 300 nm.

In this example, the total thickness of the hard coat layer 30 was 3900 nm.

In this example, the tool basic body 10 is a cemented carbide milling insert of the RPMT1204MO type, with a Co content of 10 wt.%, the remainder being WC.

(1) mixing powder raw materials of an RPMT1204MO type hard alloy milling blade, granulating, press-forming, sintering and preparing a hard alloy blank, preparing a primary cutter base body through subsequent grinding, passivating the cutting edge of the cutter to ensure that the cutting edge of the cutter has certain strength, and performing sand blasting and ultrasonic cleaning on the cutting edge to achieve good surface quality. Before formal coating, argon ions are adopted to carry out ion bombardment etching on the surface of the cutter, the flow of the argon is 240sccm, the power of an ion source is 1.5kW, the bias voltage is-650V, and the etching time is 30min, so that the quality of the surface of the cutter is further improved, the bonding strength between the coating and the base body is favorably strengthened, and the cutter base body 10 is obtained.

(2) Deposition of the interfacial adhesion layer 20: target materials (Ti) of different compositions₅₀Al₅₀、Ti₄₀Al₆₀And TiB₂) Fixing the substrate at a corresponding cathode position, raising the temperature in the furnace to 450 ℃, controlling the flow rate of argon gas to 240sccm and the flow rate of nitrogen gas to 80sccm, controlling the pressure in the furnace to be 0.45Pa by using a non-equilibrium magnetron sputtering mode, controlling the power of the TiAl target material to be 6kW and biasing to 60V, and depositing an interface bonding layer 20, namely Ti on the pretreated cutter substrate 10_0.50Al_0.50N layers;

(3) deposition support layer 31: keeping the flow of argon and the deposition temperature unchanged, increasing the flow of nitrogen to 120sccm, controlling the pressure in the furnace to be 0.5Pa, controlling the TiAl target power to be 10kW, and controlling the bias voltage to be-80V; depositing to obtain the supporting layer 31, i.e. Ti_0.40Al_0.60And N layers.

(4) Depositing a gradient composite structure multilayer coating 32: alternately depositing Ti on the support layer 31 while maintaining the deposition temperature_0.40Al_0.60An N layer and a TiBN layer 321 formed of Ti_0.40Al_0.60The N layer to the TiBN layer 321 are multi-layer coatings with a cycle period, in the multi-layer coating deposition, the flow of argon is 300sccm, the flow of nitrogen is 100sccm, the gas pressure in the furnace is 0.60Pa, the TiAl target power is fixed at 14kW, and TiB₂The target power was fixed at 4.5kW and the bias was-100V. In the first period, the opening time of the TiAl target is 23.3min, then the TiAl target is closed, and the TiB is opened₂Target, discharge time 6 min; in the second period, the opening time of the TiAl target is 17.3min, then the TiAl target is closed, and the TiB is opened₂Target, discharge time 12 min; in the third period, the opening time of the TiAl target is 13.3min, then the TiAl target is closed, and the TiB is opened₂Target, discharge time 18 min; in the fourth period, the opening time of the TiAl target is 6.7min, then the TiAl target is closed, and the TiB is opened₂Target, discharge time 24 min; in the fifth period, the opening time of the TiAl target is 2.7min, then the TiAl target is closed, and the TiB is opened₂Target, discharge time 30 min; this makes it possible to obtain a gradual increase in the thickness of the TiBN layer and Ti_1-xAl_xA gradient composite structure multilayer coating 32 of non-periodic thickness with gradually reduced N layer thickness.

(5) Deposition of the functional layer 33: the TiAl target power supply is turned off and TiB is kept₂Power on state of target material, TiB₂Fixing the target power to 4.5kW, closing a nitrogen valve, stopping introducing nitrogen, increasing the argon flow to 450sccm, adjusting the pressure in the furnace to 0.65Pa, keeping the deposition temperature unchanged, and continuously depositing a functional layer 33, namely TiB, on the surface of the gradient composite structure multilayer coating 32₂And after coating, closing all target power supplies, cooling the temperature in the furnace to be below 100 ℃ in a vacuum environment, opening the furnace door, and taking out the coating cutter, so that the high-performance hard coating cutter containing the gradient composite structure can be obtained.

The control tool 4 was a cemented carbide milling insert of the same shape and same base composition as in example 2, the coating being Ti prepared by a conventional physical vapour deposition method_0.40Al_0.60N/Al_0.60Cr_0.40N is a multi-layer coating with alternating periods, and the thickness of the coating is 3900 nm.

The control tool 5 was a cemented carbide milling insert having the same shape and same base composition as in example 2, and the coating was Ti prepared by the same unbalanced magnetron sputtering method as in this example_0.40Al_0.60N-TiB₂A double-layer coating, the inner layer being Ti_0.40Al_0.60N, the thickness ratio of the inner layer to the outer layer is 2: 1, and the total thickness of the coating is 3900 nm.

The control tool 6 was a cemented carbide milling insert of the same shape and same base composition as in example 2, the coating composition was the same as in example 2 and was prepared in the same manner as in example 2, the coating also comprising a multi-layer coating Ti_0.40Al_0.60N/TiBN coating, however, in the multilayer structure, Ti is present along the direction of coating growth_0.40Al_0.60The thickness of N layer and TiBN layer is respectively fixed and constant, and there are 5 modulation periods, and Ti in each period_0.40Al_0.60The N and TiBN thicknesses were fixed at 200nm and 100nm, respectively. Wherein the TiAlN supporting layer contains Ti_0.40Al_0.60N with a thickness of 1100nm, TiN as an interface layer with a thickness of 300nm and TiB as an outermost layer₂The thickness is 1000 nm. The total thickness of the knife coating was 3900 nm.

the processing material is sus420J 1;

the processing mode is the milling surface processing of the engine blade;

the model of the cutter is FMR01-025-XP20-RC 10-02;

cutting speed Vc is 200 m/min;

the cutting depth ap is 1.5 mm;

feed fz of each tooth is 0.45 mm/z;

a cooling mode: air cooling;

The cutter of the embodiment is used for processing 16 parts, and the normal back cutter face is worn; after 8 pieces of the contrast cutter 4 are processed, the violent abrasion fails; the cutting edge of the contrast cutter 5 processed 12 pieces is broken and failed; the cutting edge of the contrast cutter 6 processed 13 pieces of cutting edge is broken and failed. Under the condition, the service life of the cutter of the embodiment is improved by about 100 percent compared with that of the comparison cutter 1, is improved by about 33 percent compared with that of the comparison cutter 2, and is improved by about 23 percent compared with that of the comparison cutter 3. The reason for the failure of the control tool 4 is mainly the poor chemical stability of the coating, and the severe diffusion between the coating and the material being machined under high temperature conditions. The film-substrate bond strength and the coating stress distribution of the coated substrate were not optimized better for the control tool 5 and the control tool 6 than for the example 2, and therefore, the cutting edge strength of the coated tool was reduced.

Example 3

The hard coating cutter containing the gradient composite structure comprises a cutter base body 10 and a hard coating 30 deposited on the cutter base body 10, wherein the hard coating 30 comprises a gradient composite structure multilayer coating 32 and a functional layer 33 arranged on the surface of the gradient composite structure multilayer coating 32, and the functional layer 33 is TiB₂The layer, gradient composite structure multilayer coating 32 comprises alternately deposited Ti_1-xAl_xN layer 322 and TiBN layer 321, Ti_1-xAl_xX in N layer 322 is 0.5, i.e. Ti_0.50Al_0.50N layer of Ti_0.50Al_0.50The number of N/TiBN modulation cycles is 5, the first cycle: ti_0.50Al_0.50The thickness of the N layer is 350nm, the thickness of the TiBN layer 321 is 30nm, and the second period is as follows: ti_0.50Al_0.50The thickness of the N layer is 260nm, the thickness of the TiBN layer 321 is 60nm, and the third period: ti_0.50Al_0.50The thickness of the N layer is 200nm, the thickness of the TiBN layer 321 is 100nm, and the fourth period: ti_0.50Al_0.50The thickness of the N layer is 120nm, the thickness of the TiBN layer 321 is 150nm, and the fifth period is as follows: ti_0.50Al_0.50The thickness of the N layer is 40nm, and the thickness of the TiBN layer 321 is 200 nm. The gradient composite multilayer coating 32 has a total thickness of 1510 nm.

In this embodiment, the gradient composite structure multilayer coating 32 is "Ti_0.50Al_0.50N layer 322 to TiBN layer 321' is a cycle period, and the thickness of any two adjacent cycle periods is different.

In this embodiment, the functional layer 33 has a thickness of 1000 nm.

In this embodiment, the hard coating 30 further includes a supporting layer 31, the supporting layer 31 is disposed between the gradient composite structure multilayer coating 32 and the tool base 10, and the supporting layer 31 is Ti_0.50Al_0.50The N layer is of a single-phase cubic structure, and the thickness of the supporting layer 31 is 1200 nm.

In this embodiment, the hard coating 30 further includes an interfacial adhesion layer 20, the interfacial adhesion layer 20 is disposed between the support layer 31 and the tool base 10, the interfacial adhesion layer 20 is a TiN layer and has a cubic structure, and the thickness of the interfacial adhesion layer 20 is 300 nm.

In this example, the total thickness of the hard coat layer 30 is 4010 nm.

In this example, the tool base 10 was a CNM120408-EM cemented carbide turning insert with a Co content of 6 wt.%, the remainder being WC.

(1) mixing powder raw materials of a CNM120408-EM hard alloy turning blade, granulating, press-forming, sintering and preparing a hard alloy blank, preparing a primary cutter matrix through subsequent grinding, passivating the cutting edge of the cutter to ensure that the cutting edge of the cutter has certain strength, and performing sand blasting and ultrasonic cleaning on the cutting edge to achieve good surface quality. Before formal coating, argon ions are adopted to carry out ion bombardment etching on the surface of the cutter, the flow of the argon is 240sccm, the power of an ion source is 1.5kW, the bias voltage is-650V, and the etching time is 30min, so that the quality of the surface of the cutter is further improved, the bonding strength between the coating and the base body is favorably strengthened, and the cutter base body 10 is obtained.

(2) Deposition of the interfacial adhesion layer 20: target materials (Ti, Ti) of different compositions₅₀Al₅₀And TiB₂) Fixing at corresponding cathode position, increasing the temperature in the furnace to 450 deg.C by non-equilibrium magnetron sputtering, flowing argon gas 240sccm, flowing nitrogen gas 80sccm, controlling the pressure in the furnace to 0.45Pa by nitrogen gas, controlling the Ti target power to 6kW, and biasing60V, and depositing an interface bonding layer 20, namely a TiN layer on the pretreated cutter base body 10.

(3) Deposition support layer 31: the flow rate of argon gas and the deposition temperature are unchanged, the flow rate of nitrogen gas is increased to 120sccm, the gas pressure in the furnace is 0.5Pa, the TiAl target power is 15kW, the bias voltage is minus 80V, and the support layer 31, namely Ti, is obtained by deposition_0.50Al_0.50And N layers.

(4) Depositing a gradient composite structure multilayer coating 32: alternately depositing Ti on the support layer 31 at a constant deposition temperature_0.50Al_0.50An N layer and a TiBN layer 321 formed of Ti_0.50Al_0.50The N layer to the TiBN layer 321 are multi-layer coatings with a cycle period, in the multi-layer coating deposition, the flow of argon is 300sccm, the flow of nitrogen is 100sccm, the gas pressure in the furnace is 0.60Pa, the TiAl target power is gradually reduced from 16kW to 10kW, and TiB₂The target power was increased from 3kW to 5.5kW with a bias of-100V. In the first period, the TiAl target power is 16kW, the opening time is 18.6min, then the TiAl target is closed, and the TiB is opened₂Target, TiB₂The target power is 3kW, and the discharge time is 8.8 min; in the second period, the TiAl target power is 15kW, the opening time is 16.5min, then the TiAl target is closed, and the TiB is opened₂The target, the power is set to 3.5kW, and the discharge time is 15.2 min; in the third period, the TiAl target power is 14kW, the opening time is 13.3min, then the TiAl target is closed, and the TiB is opened₂The target has the power of 4kW and the discharge time of 20 min; in the fourth period, the TiAl target power is 12kW, the opening time is 8.7min, then the TiAl target is closed, and the TiB is opened₂The target, the power is set to 4.5kW, and the discharge time is 30 min; in the fifth period, the TiAl target power is 10kW, the opening time is 4.5min, then the TiAl target is closed, and the TiB is opened₂The target, the power is set as 5.5kW, and the discharge time is 31.2 min; this makes it possible to obtain a gradual increase in the thickness of the TiBN layer and Ti_0.50Al_0.50And the thickness of the N layer is gradually reduced, and the thickness of the N layer is non-periodic.

(5) Deposition of the functional layer 33: keeping the deposition temperature unchanged, turning off a TiAl target power supply and keeping TiB₂The power of the target material is in an open state, the power is 4.5kW, the nitrogen valve is closed, the introduction of nitrogen is stopped, the flow of argon is increased to 450sccm, and the air pressure in the furnace is adjustedAt 0.65Pa and a bias of-100V, the functional layer 33, i.e. TiB, is deposited on the surface of the gradient composite structure multilayer coating 32₂And (4) coating. And after the coating is finished, all target power supplies are closed, the temperature in the furnace is cooled to be below 100 ℃ in a vacuum environment, the furnace door is opened, and the coating cutter is taken out, so that the high-performance hard coating cutter containing the gradient composite structure can be obtained.

The control tool 7 was a cemented carbide turning insert of the same shape and same base composition as in example 3, the coating being commercially available TiB₂The single-layer coating is prepared by the same unbalanced magnetron sputtering method as the embodiment, and the thickness of the coating is 4000 nm.

The control tool 8 was a cemented carbide turning insert having the same shape and the same base composition as in example 3, and the coating was Ti prepared by the same unbalanced magnetron sputtering method as in this example_0.40Al_0.60N-TiB₂A double-layer coating, the inner layer being Ti_0.40Al_0.60N, the thickness ratio of the inner layer to the outer layer is 2: 1, and the total thickness of the coating is 4000 nm.

The control tool 9 was a cemented carbide turning insert of the same shape and same base composition as in example 3, the coating was of similar process parameters and coating structure as in example 3, except that it was Ti in a gradient composite multilayer structure_0.50Al_0.50The thickness of the N layer gradually increases from inside to outside, the thickness of the TiBN layer gradually decreases from inside to outside, namely a first period: ti_0.50Al_0.50The thickness of the N layer is 40nm, the thickness of the TiBN layer is 200nm, and the second period is as follows: ti_0.50Al_0.50The thickness of the N layer is 120nm, the thickness of the TiBN layer is 150nm, and the third period: ti_0.50Al_0.50The thickness of the N layer is 200nm, the thickness of the TiBN layer is 100nm, and the fourth period: ti_0.50Al_0.50The thickness of the N layer is 260nm, the thickness of the TiBN layer is 60nm, and the fifth period is as follows: ti_0.50Al_0.50The thickness of the N layer is 350nm, and the thickness of the TiBN layer is 30 nm.

The tool of the present example was compared with two control tools according to the following machining conditions:

the processing material is SUS 304;

the processing mode is excircle turning;

the cutting degree Vc is 250 m/min;

the cutting depth ap is 1 mm;

the feed amount f per revolution is 0.3 mm/r;

a cooling mode: air cooling

In the embodiment, the cutter is machined for 34 minutes, and the rear cutter face of the cutter is normally worn and fails; after the control tool 7 is machined for 20 minutes, the tool is severely worn and fails, grooves at the boundary are broken, after the control tool 8 is machined for 22 minutes, the tool is severely failed, the grooves are worn greatly, after the control tool 9 is machined for 19 minutes, the tool is severely worn and aged, and obvious groove breakage occurs at the boundary. Under the condition, compared with the comparison cutter 7, the service life of the cutter of the embodiment is improved by about 70 percent, and compared with the comparison cutter 8, the service life of the cutter is improved by about 55 percent. This example shows that the coated insert of the present invention has significant advantages in dry turning of stainless steel, severe wear at the later stages of the control tools 7, 8 and 9, and chipping at the boundaries, indicating that by the design of the present invention, the residual stress distribution of the coating is improved, the film-substrate bond strength, TiB, of the coating is improved₂The bonding strength and wear resistance between the layer and the nitride layer are improved.

Example 4

The hard coating cutter containing the gradient composite structure comprises a cutter base body 10 and a hard coating 30 deposited on the cutter base body 10, wherein the cutter base body 10 is an SEET12T3-DM type hard alloy milling blade, the content of Co is 10 wt.%, the balance is WC, the hard coating 30 comprises a gradient composite structure multilayer coating 32 and a functional layer 33 arranged on the surface of the gradient composite structure multilayer coating 32, and the functional layer 33 is TiB₂The layer, gradient composite structure multilayer coating 32 comprises alternately deposited Ti_1-xAl_xN layer 322 and TiBN layer 321, Ti_1-xAl_xN layer 322 is Ti_0.40Al_0.60N，Ti_0.40Al_0.60The N layer is a single-phase cubic structure, the TiBN layer 321 is amorphous BN coated with nanometer size TiN crystal grains and nanometer size TiB₂Nanocomposite of crystalline grainsAnd (5) combining the structures. Ti_0.40Al_0.60The number of N/TiBN modulation cycles is 6, the first cycle: ti_0.40Al_0.60The thickness of the N layer is 300nm, and the thickness of the TiBN layer 321 is 30 nm; second period: ti_0.40Al_0.60The thickness of the N layer is 240nm, and the thickness of the TiBN layer 321 is 50 nm; in the third period: ti_0.40Al_0.60The thickness of the N layer is 180nm, and the thickness of the TiBN layer 321 is 80 nm; the fourth period: ti_0.40Al_0.60The thickness of the N layer is 120nm, and the thickness of the TiBN layer 321 is 110 nm; a fifth period: ti (titanium)_0.40Al_0.60The thickness of the N layer is 80nm, and the thickness of the TiBN layer 321 is 130 nm; a sixth period: ti_0.40Al_0.60The thickness of the N layer is 40nm, the thickness of the TiBN layer 321 is 150nm, and Ti_0.40Al_0.60The total thickness of the N/TiBN gradient composite structure multi-layer coating is 1510 nm.

In this embodiment, the hard coating 30 further includes a supporting layer 31 disposed between the gradient composite structure multilayer coating 32 and the tool base 10, and an interface bonding layer 20 disposed between the supporting layer 31 and the tool base 10, wherein the supporting layer 31 has a composition of Ti_0.40Al_0.60N with a thickness of 1000nm and Ti as the interfacial adhesion layer 20_0.40Al_0.60N is cubic structure with thickness of 300nm and functional layer TiB₂Has a thickness of 1200 nm. The total thickness of the hard coating is 4010 nm.

(1) mixing powder raw materials of the SEET12T3-DM type hard alloy milling blade, granulating, press forming, sintering, preparing a hard alloy blank, subsequently grinding to prepare a primary cutter base body, passivating the cutting edge of the cutter to ensure that the cutting edge of the cutter has certain strength, and performing sand blasting and ultrasonic cleaning on the cutting edge to achieve good surface quality. Before formal coating, argon ions are adopted to carry out ion bombardment etching on the surface of the cutter, the flow of the argon gas is 240sccm, the power of an ion source is 1.5kW, the bias voltage is-650V, and the etching time is 30min, so that the quality of the surface of the cutter is further improved, the bonding strength between the coating and a substrate is enhanced, and the cutter substrate 10 is obtained.

(2) Deposition interface adhesionThe combined layer 20: target materials (Ti) of different compositions₄₀Al₆₀And TiB₂) Fixing at corresponding cathode position, increasing the temperature in the furnace to 450 deg.C, argon flow rate of 240sccm, nitrogen flow rate of 80sccm, controlling the pressure in the furnace to 0.45Pa, and turning on Ti₄₀Al₆₀Target, target power 6kW, bias-60V, deposition of an interfacial adhesion layer 20, i.e. Ti, on the pretreated tool substrate 10_0.40Al_0.60N layers;

(3) deposition support layer 31: the flow rate of argon gas and the deposition temperature are unchanged, the flow rate of nitrogen gas is increased to 120sccm, the gas pressure in the furnace is 0.5Pa, the TiAl target power is 10kW, the bias voltage is minus 80V, and the support layer 31, namely Ti, is obtained by deposition_0.40Al_0.60And N layers.

(4) Depositing the gradient composite structure multilayer coating 32: alternating Ti deposition on the support layer 31_0.40Al_0.60An N layer and a TiBN layer 321 formed of Ti_0.40Al_0.60The N layer to the TiBN layer 321 are multi-layer coatings with a cycle period, in the deposition of the multi-layer coatings, the flow of argon gas is 300sccm, the flow of nitrogen gas is 100sccm, the gas pressure in a furnace is 0.60Pa, the TiAl target power is 14kW, and TiB₂The target power was 4.5kW and the bias was-100V. In the first period, the opening time of the TiAl target is 20min, then the TiAl target is closed, and the TiB is opened₂Target, discharge time 6 min; in the second period, the opening time of the TiAl target is 16min, then the TiAl target is closed, and the TiB is opened₂Target, discharge time is 10 min; in the third period, the opening time of the TiAl target is 12min, then the TiAl target is closed, and the TiB is opened₂Target, discharge time 16 min; in the fourth period, the opening time of the TiAl target is 8min, then the TiAl target is closed, and the TiB is opened₂Target, discharge time 22 min; in the fifth period, the opening time of the TiAl target is 5.3min, then the TiAl target is closed, and the TiB is opened₂Target, discharge time 26 min; in the sixth period, the opening time of the TiAl target is 2.7min, then the TiAl target is closed, and the TiB is opened₂Target, discharge time 30 min; this makes it possible to obtain a gradual increase in the thickness of the TiBN layer and Ti_0.40Al_0.60And the N layer is a gradient composite structure multilayer coating 32 with gradually reduced thickness.

(5) Deposition of the functional layer 33:the TiAl target power supply is turned off and TiB is kept₂Turning on a power supply of the target material, wherein the power is 4.5kW, closing a nitrogen valve, stopping introducing nitrogen, increasing the flow of argon to 450sccm, adjusting the pressure in the furnace to 0.65Pa, and keeping the bias voltage at-100V, and continuously depositing a functional layer 33, namely TiB, on the surface of the gradient composite structure multilayer coating 32₂And (4) coating. And after the coating is finished, all target power supplies are closed, the temperature in the furnace is cooled to be below 100 ℃ in a vacuum environment, the furnace door is opened, and the coating cutter is taken out, so that the high-performance hard coating cutter containing the gradient composite structure can be obtained.

The control tool 10 was a cemented carbide milling insert of the same shape and same base composition as in example 4, and the coating preparation process was similar to example 4, except that: comparative tool 1 coating without outermost layer TiB₂I.e. sequentially from inside to outside is Ti_0.40Al_0.60300nm and Ti of N interface bonding layer_0.40Al_0.60N support layer 2200nm Ti with 6 alternating periods_0.40Al_0.60The N/TiBN multilayer is 1510nm, and the total thickness of the coating is kept 4010 nm.

The control tool 11 was a cemented carbide milling insert of the same shape and same base composition as in example 4, the coating being Ti prepared by the same unbalanced magnetron sputtering method as in this example_0.40Al_0.60N-TiB₂A double-layer coating, the inner layer being Ti_0.40Al_0.60N, the thickness ratio of the inner layer to the outer layer is 2: 1, and the total thickness of the coating is 4010 nm.

The control tool 12 was a cemented carbide milling insert of the same shape and same base composition as in example 4, the coating being Ti prepared by a conventional physical vapour deposition method_0.40Al_0.60N-Al_0.60Cr_0.30Si_0.10N double-layer structure coating, the inner layer is Ti_0.40Al_0.60N, the thickness ratio of the inner layer to the outer layer is 1: 2, and the total thickness of the coating is 4010 nm.

the processing material is 1Cr18Ni9 Ti;

the model of the cutter is FMA01-080-A27-SE 12-06;

the processing mode is plane milling;

cutting speed Vc is 180 m/min;

the cutting depth ap is 1.0 mm;

the cutting width ae is 60 mm;

the feed per tooth fz is 0.2 mm/z;

a cooling mode: air cooling;

the standard of the service life of the product is that the flank damage Vb of the cutter exceeds 0.2mm or the cutter is broken and fails.

After the cutter of the embodiment is machined for 58 minutes, the cutting edge is normally worn and loses efficacy; after the control cutter 10 is processed for 35 minutes, the cutting edge is severely worn and loses efficacy; after the control tool 11 is machined for 38 minutes, the cutting edge is broken; after 30 minutes of machining of the control tool 12, edge chipping occurred and chipping was severe. Under the condition, the service life of the cutter of the embodiment is improved by more than 66% compared with that of the comparison cutter 10, is improved by more than 53% compared with that of the comparison cutter 11, and is improved by more than 93% compared with that of the comparison cutter 12. From this, it can be seen that the gradient structure design of the present invention provides excellent impact resistance and wear resistance for milling 1Cr18Ni9Ti material.

Example 5

A hard coating cutter containing a gradient composite structure comprises a cutter base body 10 and a hard coating 30 deposited on the cutter base body 10, wherein the cutter base body 10 is a DNEG150404-NF type hard alloy turning blade, the content of Co is 6 wt.%, the balance is WC, the hard coating 30 comprises a gradient composite structure multilayer coating 32 and a functional layer 33 arranged on the surface of the gradient composite structure multilayer coating 32, and the functional layer 33 is TiB₂The layer, gradient composite structure multilayer coating 32 comprises alternately deposited Ti_1-xAl_xN layer 322 and TiBN layer 321, Ti_1-xAl_xN layer 322 is Ti_0.40Al_0.60N，Ti_0.40Al_0.60 The N layer 322 is a single-phase cubic structure, and the TiBN layer 321 is amorphous BN coated with nanometer size TiN grains and nanometer size TiB₂A nanocomposite structure of grains. Ti_0.40Al_0.60The number of N/TiBN modulation cycles is 4, the first cycle: ti_0.40Al_0.60Thick by N layersThe temperature is 300nm, and the thickness of the TiBN layer 321 is 50 nm; second period: ti_0.40Al_0.60The thickness of the N layer is 220nm, and the thickness of the TiBN layer 321 is 80 nm; in the third period: ti_0.40Al_0.60The thickness of the N layer is 120nm, and the thickness of the TiBN layer 321 is 140 nm; the fourth period: ti (titanium)_0.40Al_0.60The thickness of the N layer is 40nm, the thickness of the TiBN layer 321 is 200nm, and Ti_0.40Al_0.60The total thickness of the N/TiBN gradient composite structure multilayer coating 32 is 1150 nm.

In this embodiment, the hard coating 30 further includes a supporting layer 31 disposed between the gradient composite structure multilayer coating 32 and the tool base 10, and an interface bonding layer 20 disposed between the supporting layer 31 and the tool base 10, wherein the supporting layer 31 is Ti_0.40Al_0.60N with a thickness of 1200nm and a composition of Ti in the interfacial adhesion layer 20_0.50Al_0.50N is cubic structure with thickness of 300nm, and outermost functional layer TiB₂The thickness was 1350 nm. The total thickness of the hard coating is 4000 nm.

(1) mixing powder raw materials of a DNEG150404-NF type hard alloy turning blade, granulating, press-forming, sintering and preparing a hard alloy blank, preparing a primary cutter matrix through subsequent grinding, passivating the cutting edge of the cutter to ensure that the cutting edge of the cutter has certain strength, and performing sand blasting and ultrasonic cleaning on the cutting edge to achieve good surface quality. Before formal coating, argon ions are adopted to carry out ion bombardment etching on the surface of the cutter, the flow of the argon is 240sccm, the power of an ion source is 1.5kW, the bias voltage is-650V, and the etching time is 30min, so that the quality of the surface of the cutter is further improved, the bonding strength between the coating and the base body is favorably strengthened, and the cutter base body 10 is obtained.

(2) Deposition of the interfacial adhesion layer 20: target materials (Ti) of different compositions₅₀Al₅₀、Ti₄₀Al₆₀And TiB₂) Fixing the anode at the corresponding cathode position, raising the temperature in the furnace to 450 ℃ by utilizing a non-equilibrium magnetron sputtering mode, wherein the flow rate of argon is 240sccm, the flow rate of nitrogen is 80sccm, the pressure in the furnace is controlled to be 0.45Pa by the nitrogen, and the work of the Ti target material is performedA rate of 6kW, bias of-60V, depositing an interfacial adhesion layer 20, i.e. Ti, on the pretreated tool substrate 10_0.50Al_0.50And N layers.

(4) Depositing a gradient composite structure multilayer coating 32: alternating Ti deposition on the support layer 31_0.40Al_0.60An N layer and a TiBN layer 321 formed of Ti_0.40Al_0.60The N layer to the TiBN layer 321 are multi-layer coatings with a cycle period, in the multi-layer coating deposition, the flow of argon is 300sccm, the flow of nitrogen is 100sccm, the gas pressure in the furnace is 0.60Pa, the TiAl target power is 14kW, and TiB₂The target power was 4.5kW and the bias was-120V. In the first period, the opening time of the TiAl target is 20min, then the TiAl target is closed, the TiB2 target is opened, and the discharge time is 10 min; in the second period, the opening time of the TiAl target is 14.6min, then the TiAl target is closed, and the TiB is opened₂Target, discharge time 16 min; in the third period, the opening time of the TiAl target is 8min, then the TiAl target is closed, and the TiB is opened₂Target, discharge time 28 min; in the fourth period, the opening time of the TiAl target is 2.8min, then the TiAl target is closed, and the TiB is opened₂Target, discharge time 40 min; this makes it possible to obtain a gradual increase in the thickness of the TiBN layer and Ti_0.40Al_0.60And the N layer is a gradient composite structure multilayer coating 32 with gradually reduced thickness.

(5) Deposition of the functional layer 33: the TiAl target power supply is turned off and TiB is kept₂Turning on a power supply of the target material, wherein the power is 4.5kW, closing a nitrogen valve, stopping introducing nitrogen, increasing the flow of argon to 450sccm, adjusting the pressure in the furnace to 0.65Pa, and keeping the bias voltage at-140V, and continuously depositing a functional layer 33, namely TiB, on the surface of the gradient composite structure multilayer coating 32₂And (4) coating. And after the coating is finished, all target power supplies are closed, the temperature in the furnace is cooled to be below 100 ℃ in a vacuum environment, the furnace door is opened, and the coating cutter is taken out, so that the high-performance hard coating cutter containing the gradient composite structure can be obtained.

The control tool 13 was a cemented carbide turning insert of the same shape and same base composition as in example 5, coated with TiN-TiB produced by CVD₂A coating layer with a double-layer structure, the thickness of TiN layer is 1300nm, TiB₂The layer thickness was 2700nm and the total coating thickness was 4000 nm.

The control tool 14 was a cemented carbide turning insert of the same shape and same base composition as in example 5, coated with Ti with a high Al content_0.30Al_0.70N coating, and the total thickness of the coating is 4000 nm.

The control tool 15 was a cemented carbide turning insert of the same shape and same base composition as in example 5, the coating being commercially available TiB₂The single-layer coating is prepared by the same unbalanced magnetron sputtering method as the embodiment, and the thickness of the coating is 4000 nm.

The control tool 16 was a cemented carbide turning insert having the same shape and same base composition as in example 5, and the coating was Ti prepared by the same unbalanced magnetron sputtering method as in this example_0.50Al_0.50N-TiB₂A double-layer coating, the inner layer being Ti_0.50Al_0.50N, the thickness ratio of the inner layer to the outer layer is 1: 2, and the total thickness of the coating is 4000 nm.

The control tool 17 was a cemented carbide turning insert having the same shape and same base composition as in example 5, and the coating was Ti prepared by the same unbalanced magnetron sputtering method as in this example_0.40Al_0.60N-TiB₂A double-layer coating, the inner layer being Ti_0.40Al_0.60N, the thickness ratio of the inner layer to the outer layer is 2: 1, and the total thickness of the coating is 4000 nm.

The tool of the present example was subjected to a comparative test with five control tools under the following cutting conditions:

the processing material is Inconel 718;

the processing mode is external turning;

the cutting degree Vc is 80 m/min;

the cutting depth ap is 0.3 mm;

the feed amount f per revolution is 0.15 mm/r;

a cooling mode: water cooling

After the cutter of the embodiment is machined for 20 minutes, the abrasion Vb of the rear cutter face of the cutter is about 0.104 mm; the wear Vb of the flank face of the cutter after 20 minutes of machining by the control cutter 13 was about 0.125mm, the wear Vb of the flank face of the cutter after 20 minutes of machining by the control cutter 14 was about 0.186mm, the wear Vb of the flank face of the cutter after 20 minutes of machining by the control cutter 15 was about 0.436mm, sticky debris was serious and failed, the wear Vb of the flank face of the cutter after 20 minutes of machining by the control cutter 16 was about 0.418mm, sticky debris was serious and failed, and the wear Vb of the flank face of the cutter after 20 minutes of machining by the control cutter 17 was about 0.165 mm. The cutting times at full life were 45, 30, 23 and 25 minutes at full failure for the coated, control 13, control 14 and control 17 tools of example 5, respectively, so the tool life of this example was increased by about 50% over the control 13 and about 95% and 80% over the control 14 and 17 tools. Therefore, the coated cutting tool still has very obvious advantages under the water cooling condition, and shows that the gradient multilayer structure design of the invention optimizes the stress distribution of the coating, and the film-substrate bonding strength and TiB₂The bonding strength between the layer and the nitride layer is enhanced.

The foregoing is merely a preferred embodiment of the invention and is not intended to limit the invention in any manner. Although the present invention has been described with reference to the preferred embodiments, it is not intended to be limited thereto. Those skilled in the art can make many possible variations and modifications to the disclosed embodiments, or equivalent modifications, without departing from the spirit and scope of the invention, using the methods and techniques disclosed above. Therefore, any simple modification, equivalent replacement, equivalent change and modification made to the above embodiments according to the technical essence of the present invention are still within the scope of the protection of the technical solution of the present invention.

Claims

1. AThe hard coating cutter containing the gradient composite structure is characterized by comprising a cutter base body (10) and a hard coating (30) deposited on the cutter base body (10), wherein the hard coating (30) comprises a gradient composite structure multilayer coating (32) and a functional layer (33) arranged on the surface of the gradient composite structure multilayer coating (32), and the functional layer (33) is TiB₂Layers, the gradient composite structure multilayer coating (32) comprising alternately deposited Ti_1-xAl_xAn N layer (322) and a TiBN layer (321), the Ti_1- _xAl_xX is more than or equal to 0.3 and less than or equal to 0.7 in the N layer (322), and the Ti_1-xAl_xThe thickness of the N layer (322) is controlled to be 20 nm-500 nm, the thickness of the TiBN layer (321) is controlled to be 10 nm-500 nm, and the Ti_1-xAl_xThe thickness of the N layer (322) is reduced along with the distance from the cutter base body (10), the thickness of the TiBN layer (321) is increased along with the distance from the cutter base body (10), and the gradient composite structure multilayer coating (32) at least comprises two periods of alternate deposition.

2. The gradient composite structure-containing hard coated tool according to claim 1, wherein the Ti is_1-xAl_xThe thickness of the N layer (322) is controlled to be 40 nm-400 nm, and the thickness of the TiBN layer (321) is controlled to be 20 nm-300 nm.

3. The gradient composite structure-containing hard coated tool according to claim 1, wherein the Ti is_1-xAl_xThe N layer (322) is a single-phase cubic structure, and the TiBN layer (321) is formed by wrapping nano-sized TiN crystal grains and nano-sized TiB with amorphous BN₂A nanocomposite structure of grains.

4. The gradient composite structure-containing hard coated tool according to claim 1, wherein the Ti is_1-xAl_xIn the N layer (322), x is more than or equal to 0.4 and less than or equal to 0.6.

5. The hard coated cutting tool with a gradient composite structure of claim 1 wherein the gradient composite structure is a multilayerThe coating (32) is' Ti_1-xAl_xN layers (322) to TiBN layers (321) "are a cycle period, and the first layer of the gradient composite structure multilayer coating (32) is Ti_1-xAl_xThe thickness of any two adjacent circulation periods is different, and the thickness of the circulation periods is in a decreasing trend from the direction close to the cutter base body (10) to the direction far away from the cutter base body (10).

6. The hard coated tool with a gradient composite structure according to any of claims 1 to 5, characterized in that the total thickness of the gradient composite structure multilayer coating (32) is 500nm to 3000 nm.

7. The hard coated tool with a gradient composite structure according to any of claims 1 to 5, characterized in that the thickness of the functional layer (33) is 500nm to 3000 nm.

8. The gradient composite structure-containing hard coated cutting tool according to claim 7, wherein the hard coating (30) further comprises a support layer (31), the support layer (31) being provided between the gradient composite structure multilayer coating (32) and the tool base body (10), the support layer (31) being Ti_1-yAl_yN layer, y is more than or equal to 0.3 and less than or equal to 0.7, and the Ti_1-yAl_yN layer and the Ti_1- _xAl_xThe N layer (322) has the same composition and structure, and the thickness of the support layer (31) is 500 nm-3000 nm.

9. The tool of claim 8, wherein the hard coating (30) further comprises an interfacial adhesion layer (20), the interfacial adhesion layer (20) being disposed between the support layer (31) and the tool base (10), the interfacial adhesion layer (20) being Ti_1-aAl_aAnd a is more than or equal to 0 and less than or equal to 0.7, and the thickness of the interface bonding layer (20) is 50 nm-1000 nm.

10. The gradient-containing complex of claim 9A composite structure hard coated tool, characterized in that said Ti_1-aAl_aIn the N layer, a is more than or equal to 0 and less than or equal to 0.6.

11. The gradient composite structure-containing hard coated tool according to claim 9, wherein the Ti is_1-aAl_aThe N layer is of a cubic structure.

12. The hard coated tool with a gradient composite structure according to any of claims 8 to 11, characterized in that the total thickness of the hard coating (30) is 1500nm to 10000 nm.

13. A method of making a hard coated cutting tool comprising a gradient composite structure according to any of claims 9 to 12, comprising the steps of:

s1, depositing the interface bonding layer (20): depositing an interface bonding layer (20) on the pretreated cutter substrate (10) by adopting a non-equilibrium magnetron sputtering method;

s2, deposition support layer (31): depositing a supporting layer (31) on the interface bonding layer (20) by adopting a non-equilibrium magnetron sputtering method;

s3, depositing the gradient composite structure multilayer coating (32): alternately depositing Ti on the supporting layer (31) by adopting an unbalanced magnetron sputtering method_1-xAl_xAn N layer (322) and a TiBN layer (321) deposited under the following conditions: introducing argon gas flow of 300-340 sccm, nitrogen gas flow of 100-120 sccm, controlling the pressure to be 0.60-0.70 Pa, bias voltage to be-100V-150V, deposition temperature to be 400-500 ℃, and depositing Ti when Ti is deposited_1-xAl_xWhen N layer (322) is formed, starting a TiAl target power supply, gradually reducing the power of the TiAl target from 18kW to 8kW in the discharge time period of the corresponding period according to the difference of the cycle period number, closing the TiAl target power supply when the TiBN layer (321) is deposited, and starting TiB₂Target power supply, TiB depending on the number of cycles₂The power of the target was gradually increased from 3kW to 10kW during the discharge period of the corresponding cycle, or when Ti was deposited_1-xAl_xWhen the N layer (322) and the TiBN layer (321) are used, the power for fixing the TiAl target is 10 kW-15 kW,TiB₂The power of the target is 4 kW-5 kW, and TiB is closed alternately₂Target, turn on TiAl target or turn on TiB₂Target, TiAl target turned off to deposit the corresponding Ti_1-xAl_xAn N layer (322) and a TiBN layer (321), and gradually reduce the discharge time of the TiAl target in the corresponding period and prolong TiB according to the difference of the cycle period number₂Discharge time of target, Ti deposition by alternation_1-xAl_xObtaining a gradient composite structure multilayer coating (32) after the N layer (322) and the TiBN layer (321);

s4, depositing a functional layer (33): and depositing a functional layer (33) on the gradient composite structure multilayer coating (32) to obtain the hard coating cutter containing the gradient composite structure.

14. The method for preparing a hard coated cutting tool with a gradient composite structure according to claim 13, wherein in step S1, the interfacial adhesion layer (20) is deposited under the following conditions: introducing argon and nitrogen, wherein the flow of the argon is 220 sccm-260 sccm, the flow of the nitrogen is 80 sccm-100 sccm, the pressure is controlled by the nitrogen to be kept at 0.40 Pa-0.50 Pa, the power of the TiAl target is controlled to be 5 kW-8 kW, the bias voltage is-50V-80V, and the deposition temperature is 400-500 ℃.

15. The method for preparing a hard coated cutting tool comprising a gradient composite structure according to claim 13, wherein the deposition conditions of the support layer (31) in step S2 are as follows: controlling the flow of argon gas to be 220 sccm-260 sccm, the flow of nitrogen gas to be 100 sccm-120 sccm, controlling the pressure to be 0.50 Pa-0.60 Pa by nitrogen gas, controlling the power of the TiAl target to be 10 kW-15 kW, controlling the bias voltage to be-80V-100V, and controlling the deposition temperature to be 400-500 ℃.

16. The method for producing a hard coated cutting tool comprising a gradient composite structure according to claim 13, wherein in step S4, the deposition process of the functional layer (33) is: closing the TiAl target power supply, stopping introducing nitrogen, increasing the argon flow to 400-500 sccm, controlling the pressure in the chamber to be 0.60-0.70 Pa, and TiB₂Adjusting the power of a target power supply to 4 kW-5 kW, and beginning to deposit TiB₂A layer of a material selected from the group consisting of,the deposition temperature is 400-500 ℃, the bias voltage is-80V-150V, after the deposition is finished, the power supply is closed, and the product is taken out after the indoor temperature is cooled to be below 100 ℃.

17. The method for preparing a hard coated cutting tool with a gradient composite structure according to any one of claims 13 to 16, wherein the step S1 is that the pretreatment of the cutting tool base body (10) comprises surface sand blasting, ultrasonic cleaning and ion etching cleaning, and the ion etching cleaning comprises the following steps: starting an ion source, introducing argon gas of 200 sccm-300 sccm into the ion source, setting the power of the ion source to be 1.5kW, the bias voltage to be-500V-800V, and the etching cleaning time to be 20 min-35 min.