CN108103472B

CN108103472B - Composite coating cutter and preparation method thereof

Info

Publication number: CN108103472B
Application number: CN201711451155.7A
Authority: CN
Inventors: 李翠; 张敏捷
Original assignee: Funik Ultrahard Material Co Ltd
Current assignee: Funik Ultrahard Material Co Ltd
Priority date: 2017-12-27
Filing date: 2017-12-27
Publication date: 2020-04-14
Anticipated expiration: 2037-12-27
Also published as: CN108103472A

Abstract

The invention relates to a composite coating cutter and a preparation method thereof, belonging to the technical field of composite coating cutters. The composite coating cutter comprises a cutter base body, and a diamond layer and a nitride layer which are sequentially arranged from the surface of the cutter base body to the outside. According to the composite coating cutter, the nitride layer is arranged outside the diamond layer, the high temperature resistance and the corrosion resistance of the composite coating cutter are improved by utilizing the red hardness of the nitride, the diamond is not bonded with cast iron, VIII group element metal and alloy thereof, and the processing performance of the diamond coating and the nitride composite coating on the cast iron, black metal, VIII group element metal and alloy thereof is effectively promoted.

Description

Composite coating cutter and preparation method thereof

Technical Field

The invention relates to a composite coating cutter and a preparation method thereof, belonging to the technical field of composite coating cutters.

Background

The conventional hard alloy serving as one of main materials of a machining cutter and a wear-resistant part is increasingly difficult to meet the development requirement, and the successful development and application of the diamond low-pressure chemical vapor deposition method lays a foundation for researching and developing a diamond-coated hard alloy composite product. Compared with diamond single crystal and diamond composite material, the diamond coating hard alloy product has low cost and less shape limitation, and the service performance of the diamond coating hard alloy product can be comparable to that of the diamond single crystal and the diamond composite material. However, the thermal expansion coefficients of the hard alloy substrate and the diamond coating are very different, so that the interface bonding force between the substrate and the coating is weak, and the current research mainly focuses on the aspects of how to improve the interface bonding force between the substrate and the diamond coating and the like.

The diamond coating hard alloy product is mainly used as a cutting tool, but because ferrous metal and VIII group element metals such as Co, Ni and the like are C solvent in a molten state, carbon atoms of diamond are dissolved into metal lattices at local high temperature in the mechanical processing process, and cutting edges of the diamond and diamond-related coating products cannot work continuously. Through increasing the cutting fluid, when making diamond coating instrument blade processing work piece, the temperature reduces relatively, makes diamond coating instrument processing ferrous metal to because the characteristic of high rigidity high strength, the effect is excellent, but because the cutting fluid of adding can cause bad influence to the environment, is unfavorable for green. Therefore, how to make the diamond coated cutting tool maintain the characteristics of high hardness, high strength and the like when processing ferrous metals, metals of VIII group elements such as Co, Ni and the like and alloy materials thereof, and simultaneously, the diamond coated cutting tool does not influence the environment, thereby becoming a problem to be solved urgently.

Disclosure of Invention

The invention aims to provide a composite coating cutter which can be used for processing ferrous metals, metals of VIII groups such as Co, Ni and the like and alloy materials thereof.

The invention also provides a preparation method of the composite coating cutter.

In order to achieve the above purpose, the composite coating cutter of the invention adopts the technical scheme that:

a composite coating cutter comprises a cutter base body, and a diamond layer and a nitride layer which are sequentially arranged from the surface of the cutter base body to the outside.

The composite coating cutter of the invention is provided with the nitride layer outside the diamond layer, and the red hardness of the nitride is utilized, so that the high temperature resistance and the corrosion resistance of the composite coating cutter are improved, the diamond is not bonded with cast iron, black metal, VIII group element metal and alloy thereof, and the processing performance of the diamond coating and the nitride composite coating on the cast iron, the black metal, the VIII group element metal and the alloy thereof is effectively promoted. Due to the existence of the high-hardness diamond coating, the hardness value of the composite coating on the surface of the cutter substrate is improved, and the high-temperature resistance and the toughness of the composite coating can be improved by the compact-structure nitride layer. The high hardness and toughness values increase the machining strength of the composite coated tool, enabling it to be used for rough machining and interrupted machining.

A titanium metal layer is arranged between the diamond layer and the nitride layer, and a titanium carbide transition layer is also arranged between the titanium metal layer and the diamond layer. Set up titanium metal layer and titanium carbide transition layer between diamond layer and nitride layer, can strengthen nitride etc. and diamond layer between the bonding strength, the use does not have nitride and drops the phenomenon, has prolonged the life of composite coating cutter.

The thickness of the titanium metal layer is 0.01-0.2 μm, and the thickness of the titanium carbide layer is 0.01-0.1 μm.

The nitride layer forms a thermal barrier at the tool surface as the workpiece is cut. The nitride layer is composed of a nitride; the nitride is composed of at least one element of Ti, Si, Al, Cr and Zr and N element.

Preferably, the nitride is composed of at least one element selected from Si, Al, Cr and Zr, Ti and N.

Preferably, the nitride is composed of Ti, Si, Al and N elements. The atomic molar ratio of Ti, Si and Al in the nitride is 1-3: 0.05-0.3: 2-3. The N element participates in the formation of nitrogen compounds close to the stoichiometric ratio by other elements in the formation process of the coating compound. However, in the coating composition, the exact value of the actual ratio of N atoms to atoms of other elements in the nitride is difficult to determine, as in the case of the unknown number x instead of the relative molar ratio of nitrogen.

The thickness of the nitride layer is 2-6 mu m; the thickness of the diamond layer is 3-15 mu m.

The base body of the cutter is made of hard alloy and Si₃N₄One kind of ceramic. When the hard alloy is used as the cutter substrate, the diamond coating can be directly arranged on the hard alloy, and a coating for improving the bonding performance of the hard alloy and the diamond can be arranged between the hard alloy and the diamond layer.

The preparation method of the composite coating cutter adopts the technical scheme that:

the preparation method of the composite coating cutter comprises the following steps: depositing nitride on the diamond coating cutter to form a nitride layer; the diamond coated cutting tool includes a cutting tool substrate and a diamond layer coated on the cutting tool substrate.

The preparation method of the composite coating cutter has simple process and is convenient to popularize and apply.

The preparation method of the diamond-coated cutter comprises the following steps: sequentially carrying out alkali washing, cobalt removal and seed crystal seeding on the cutter substrate, and then depositing a diamond layer on the cutter substrate to obtain the cutting tool; the cutter base body is made of hard alloy.

The washing liquid used for the alkaline washing is obtained by mixing hydroxide, ferricyanide and water according to the mass ratio of 1: 0.8-1.3: 8-13. The hydroxide is at least one of sodium hydroxide and potassium hydroxide. The ferricyanide is at least one of potassium ferricyanide and sodium ferricyanide. And during alkaline cleaning, putting the cutter substrate into a cleaning solution for ultrasonic treatment for 20-30 min. After the alkali washing, the tool base was washed with water.

And (3) removing cobalt by adopting an acid washing mode. The washing liquid used for acid washing is obtained by mixing sulfuric acid and hydrogen peroxide according to the mass ratio of 1: 1-2.4. The mass fraction of the hydrogen peroxide is 30-50%, and the mass fraction of the sulfuric acid is 97-99%. And during acid cleaning, the cutter substrate is placed into a cleaning solution to be soaked for 5-40 s. Preferably, the time for soaking the cutter substrate in the washing liquid is 20-40 s. After the pickling, the tool base is washed with water.

The method for seed crystal comprises the following steps: and putting the acid-washed cutter substrate into the nano-diamond suspension for ultrasonic treatment. The particle size of the nano diamond is 20-60 nm. In the process of seed crystal planting, the ultrasonic treatment time is 20-50 min. And taking out the tool substrate after seed crystal, and washing the tool substrate by using water.

When the tool base is washed with water, deionized water may be used. If the cutter substrate can be put into water for ultrasonic treatment for 2-10 min, the cutter substrate is washed.

And depositing a diamond film on the cutter substrate by adopting a hot wire CVD method to form a diamond layer. The hot wire CVD method is carried out by reacting the reaction source with 1Depositing for 5-15 h at 800-1200 ℃ under the condition of-2.4 kPa. The reaction source is H₂And a carbon source. The carbon source is CH₄。

The nitride is deposited on the diamond coated tool by a vapor deposition method, such as magnetron sputtering. Preferably, the nitride is deposited on the diamond-coated tool by a pulsed magnetron sputtering method. The magnetron sputtering coating machine is adopted for depositing the nitride on the diamond coating cutter by adopting a pulse magnetron sputtering method. The pulse magnetron sputtering method is characterized in that in a mixed atmosphere of nitrogen and argon, the temperature is controlled to be 500-550 ℃, the bias power supply voltage is 70-100V, the pulse frequency of a target power supply is 500-1000 Hz, the power of the target power supply is 8000-10000 kW, and the sputtering is carried out for 2.5-7 h. The target material adopted during the nitride deposition can be a target material with corresponding component elements according to the composition of the nitride. If the deposited nitride consists of three elements of Ti, Si and Al and N, a titanium-aluminum target material and a silicon-titanium target material can be adopted. The proportion of each metal atom in the titanium-aluminum target material and the silicon-titanium target material is selected according to the molar ratio of atoms of Ti, Si and Al in the nitride. In the mixed atmosphere of nitrogen and argon, the partial pressure of nitrogen is 400-600 MPa. And in the mixed atmosphere of nitrogen and argon, the partial pressure of the argon is 250-300 MPa.

Before depositing nitride on the diamond coated cutter, firstly depositing titanium metal on the diamond coated cutter to sequentially form a titanium carbide layer and a titanium metal layer in the direction far away from the diamond coated cutter.

The titanium metal is deposited on the diamond-coated cutting tool by a vapor deposition method, such as a magnetron sputtering method. Preferably, the titanium metal is deposited on the diamond-coated tool by a pulsed magnetron sputtering method. The magnetron pulse sputtering method is to sputter for 25-35 min in an argon atmosphere at a controlled temperature of 500-550 ℃, a bias power supply voltage of 70-100V, a target power supply pulse frequency of 500-1000 Hz and a target power supply power of 2000-3000 kW. The target material for depositing the titanium metal layer is a Ti target material. When depositing the titanium metal layer, Ti ion combines with the carbon source chemical reaction of diamond, similar with the principle of diamond particle surface titanizing, metal titanium reacts with carbon and forms the TiC transition layer: and diamond (C) -TiC-Ti, wherein a metal titanium layer is deposited on the diamond layer by adopting a physical vapor deposition method, so that the chemical bonding force between the metal titanium layer and the diamond layer is improved.

When nitride and titanium metal are deposited, a high-power pulse magnetron sputtering method is adopted, a sputtering metal target generates a large amount of ionization, megawatt-level high-energy pulses are given to the target, high-load-density plasma is formed on the surface of the target, and the layer structure and the layer characteristics of the coating are improved powerfully, because the residual stress of the coating obtained by high-energy sputtering is small, the binding force between the coatings is increased and is larger than the shearing force.

Before depositing titanium metal on the diamond coating cutter, the diamond layer of the diamond coating cutter is subjected to sand blasting, glow discharge cleaning and ion etching in sequence.

The medium adopted by the sand blasting treatment is Al₂O₃. The pressure of the sand blasting treatment is 3-4 MPa, and the time is 8-15 min. And (3) washing the diamond coating cutter with water after the sand blasting treatment, and if the diamond coating cutter can be placed in water for ultrasonic treatment for 50-80 min.

The glow discharge cleaning and the ion etching are both carried out in magnetron sputtering coating equipment.

The glow discharge cleaning is to clean the diamond coating cutter for 40-180 min in an argon atmosphere in magnetron sputtering coating equipment at the temperature of 500-550 ℃ and the bias voltage of 1000-1100V.

The ion etching is carried out in a magnetron sputtering coating device, the temperature is controlled to be 500-550 ℃, the power of a target power supply is 2000-3500 kW, the voltage of a bias power supply is 600-800V, the pulse frequency of the target power supply is 500-1000 Hz, and the target is started to bombard a diamond coating cutter for 25-35 min in an argon atmosphere. The target material adopted by the ion etching is a Ti target material or a titanium aluminum target material.

Before the ion etching and the nitride deposition are carried out, the magnetron sputtering coating equipment is vacuumized to 1 x 10^-3Pa. In the process of ion etching and titanium metal deposition, the flow of the filled argon is 80-120 sccm so as to maintain the required argon atmosphere. And during glow discharge cleaning, the rotating speed of the turntable is 0-5 min/r. Ion etching, titanium metal deposition and nitrogen depositionIn the process of material preparation, the rotating speed of the rotary table is 1-5 min/r. Preferably, the rotating speed of the turntable is 1-3 min/r in the processes of ion etching, titanium metal deposition and nitride deposition.

Drawings

FIG. 1 is a schematic structural view of a composite coated cutting tool according to example 1; the cutting tool comprises a cutting tool base body 1, a diamond layer 2, a titanium carbide transition layer 3, a titanium metal layer 4 and a nitride layer 5.

Detailed Description

The technical solution of the present invention will be further described with reference to the following embodiments.

In a specific embodiment, the cutter base bodies adopted in examples 1 to 5 are YG6 cemented carbide blades with a specification of VNGA 160404; example 6 the tool base used was Si₃N₄Ceramic, specification VNGA 160404.

Example 1

The composite coating cutter of the embodiment, as shown in fig. 1, comprises a cutter substrate 1, and a diamond layer 2, a titanium carbide (TiC) transition layer 3, a titanium metal layer 4 and a nitride layer 5 which are sequentially arranged from the surface of the cutter substrate to the outside; the thickness of the diamond layer is 4 μm, the thickness of the titanium carbide transition layer is 0.01 μm, the thickness of the titanium metal layer is 0.01 μm, and the thickness of the nitride layer is 3 μm; the nitride layer is made of a nitride of Ti₂Si_0.1Al₂N_x。

The preparation method of the composite coating cutter of the embodiment comprises the following steps:

1) mixing potassium ferricyanide, a hydrogen oxidant and deionized water according to a mass ratio of 1:1:10 to obtain an alkaline solution, then putting the cutter substrate into the alkaline solution for ultrasonic treatment for 25min, taking out the cutter substrate, and putting the cutter substrate into the deionized water for ultrasonic treatment for 3min to wash;

2) mixing sulfuric acid and hydrogen peroxide according to a volume ratio of 3:7 to obtain a pickling solution, soaking the cutter substrate washed in the step 1) in the pickling solution for 10s to remove cobalt, taking out, and placing in deionized water for ultrasonic treatment for 60min to wash; the mass fraction of the adopted sulfuric acid is 97 percent, and the mass fraction of the hydrogen peroxide is 30 percent;

3) putting the cutter substrate washed in the step 2) into the nano-diamond suspension for ultrasonic treatment for 30min, taking out, and putting into deionized water for ultrasonic treatment for 3min for washing; the particle size of the nano diamond is 30 nm;

4) depositing a diamond film on the surface of the cutter substrate washed in the step 3) by adopting a hot wire CVD method to form a diamond layer, and preparing a diamond coated cutter; deposition by hot filament CVD with H₂And CH₄As a reaction source, the deposition time is 5h under the conditions that the pressure is 1kPa and the temperature is 800 ℃;

5) mechanically blasting the diamond layer of the diamond coating cutter in the step 4), wherein the medium for blasting is alumina, the pressure is 3.5MPa, and the time is 10 min; washing for 1h by using deionized water after sand blasting treatment;

6) placing the diamond coating cutter washed in the step 5) in a cavity of a magnetron sputtering coating machine, and vacuumizing to 1 x 10^-3Pa, heating to 500 ℃, introducing argon at the flow of 80sccm, setting the bias power voltage to 1100V, and performing glow discharge cleaning on the diamond coating cutter for 60 min;

using Ti as a target material, setting the power supply power of the target material to be 2000kW, the pulse frequency of the power supply of the target material to be 500Hz, the voltage of a bias power supply to be 800V and the rotating speed of a rotary table to be 1min/r, and starting the target material to bombard for 30 min; then reducing the bias power voltage to 100V, and starting the Ti target material for sputtering for 30 min;

changing the target materials into a titanium-aluminum target material and a silicon-titanium target material, vacuumizing, introducing argon and nitrogen to ensure that the partial pressure of the argon is 250MPa and the partial pressure of the nitrogen is 450MPa, wherein the flow of the nitrogen is 80sccm, setting the voltage of a bias power supply to be 80V, adjusting the power of the target material to be 8000kW, and starting the target material to sputter for 3 hours; and (5) cooling to obtain the product.

Example 2

The composite coating cutter comprises a cutter base body, and a diamond layer, a titanium carbide (TiC) transition layer, a titanium metal layer and a nitride layer which are sequentially arranged from the surface of the cutter base body to the outside; the thickness of the diamond layer is 8 μm, the thickness of the titanium carbide transition layer is 0.05 μm, the thickness of the titanium metal layer is 0.1 μm, and the thickness of the nitride layer is 4 μm; nitrogen is present inThe nitride layer is made of a nitride of Ti₂Si_0.1Al₃N_x。

1) mixing potassium ferricyanide, a hydrogen oxidant and deionized water according to the mass ratio of 1:0.8:8 to obtain an alkaline solution, then putting the cutter substrate into the alkaline solution for ultrasonic treatment for 25min, taking out the cutter substrate, and putting the cutter substrate into the deionized water for ultrasonic treatment for 3min to wash;

2) mixing sulfuric acid and hydrogen peroxide according to the volume ratio of 1:1 to obtain a pickling solution, soaking the cutter substrate washed in the step 1) in the pickling solution for 20s for decobalting, taking out, and placing in deionized water for ultrasonic treatment for 90min for washing; the mass fraction of the adopted sulfuric acid is 99 percent, and the mass fraction of the hydrogen peroxide is 40 percent;

3) putting the cutter substrate washed in the step 2) into the nano-diamond suspension for ultrasonic treatment for 50min, taking out, and putting into deionized water for ultrasonic treatment for 3min for washing; the particle size of the nano diamond is 45 nm;

4) depositing a diamond film on the surface of the cutter substrate washed in the step 3) by adopting a hot wire CVD method to form a diamond layer, and preparing a diamond coated cutter; deposition by hot filament CVD with H₂And CH₄As a reaction source, the deposition time is 10 hours under the conditions that the pressure is 2.4kPa and the temperature is 1000 ℃;

5) mechanically blasting the diamond layer of the diamond coating cutter in the step 4), wherein the medium for blasting is alumina, the pressure is 3MPa, and the time is 15 min; washing for 1h by using deionized water after sand blasting treatment;

6) placing the diamond coating cutter washed in the step 5) in a cavity of a magnetron sputtering coating machine, and vacuumizing to 1 x 10^-3Pa, heating to 550 ℃, introducing argon at the flow of 120sccm, setting the bias power supply voltage to 1000V, and performing glow discharge cleaning on the diamond coating cutter for 60 min;

setting the power of a target power supply to 3500kW, the pulse frequency of the target power supply to 600Hz, the voltage of a bias power supply to 600V and the rotating speed of a rotary table to 2min/r, and starting the Ti target to bombard for 30 min; then reducing the bias power voltage to 80V, and starting the Ti target material for sputtering for 30 min;

then changing the target materials into a titanium-aluminum target material and a silicon-titanium target material, vacuumizing, introducing argon and nitrogen to ensure that the partial pressure of the argon is 250MPa, the partial pressure of the nitrogen is 460MPa and the introduction flow of the nitrogen is 90sccm, setting the voltage of a bias power supply to be 80V, adjusting the power of the target material to be 10000kW, and starting the target material to sputter for 4 hours; and (5) cooling to obtain the product.

Example 3

The composite coating cutter comprises a cutter base body, and a diamond layer, a titanium carbide (TiC) transition layer, a titanium metal layer and a nitride layer which are sequentially arranged from the surface of the cutter base body to the outside; the thickness of the diamond layer is 12 microns, the thickness of the titanium carbide transition layer is 0.08 microns, the thickness of the titanium metal layer is 0.13 microns, and the thickness of the nitride layer is 5 microns; the nitride layer is made of a nitride of Ti₂Si_0.3Al₃N_x。

1) mixing potassium ferricyanide, a hydrogen oxidant and deionized water according to the mass ratio of 1:1.3:13 to obtain an alkaline solution, then putting the cutter substrate into the alkaline solution for ultrasonic treatment for 25min, taking out the cutter substrate, and putting the cutter substrate into the deionized water for ultrasonic treatment for 3min to wash;

2) mixing sulfuric acid and hydrogen peroxide according to the volume ratio of 2:3 to obtain a pickling solution, soaking the cutter substrate washed in the step 1) in the pickling solution for 30s to remove cobalt, taking out, and placing in deionized water for ultrasonic treatment for 90min to wash; the mass fraction of the adopted sulfuric acid is 98 percent, and the mass fraction of the hydrogen peroxide is 35 percent;

3) putting the cutter substrate washed in the step 2) into the nano-diamond suspension for ultrasonic treatment for 20min, taking out, and putting into deionized water for ultrasonic treatment for 3min for washing; the particle size of the nano diamond is 60 nm;

4) depositing a diamond film on the surface of the cutter substrate washed in the step 3) by adopting a hot wire CVD method to form a diamond layer, and preparing a diamond coated cutter; heat generationDeposition by filament CVD with H₂And CH₄As a reaction source, the deposition time is 10h under the conditions that the pressure is 1.7kPa and the temperature is 1100 ℃;

5) mechanically blasting the diamond layer of the diamond coating cutter in the step 4), wherein the medium for blasting is alumina, the pressure is 4MPa, and the time is 8 min; washing for 1h by using deionized water after sand blasting treatment;

6) placing the diamond coating cutter washed in the step 5) in a cavity of a magnetron sputtering coating machine, and vacuumizing to 1 x 10^-3Pa, heating to 520 ℃, introducing argon at the flow of 100sccm, setting the bias power voltage to 1050V, and performing glow discharge cleaning on the diamond coated cutter for 60 min;

using Ti as a target material, setting the power supply power of the target material to 2800kW, setting the pulse frequency of the power supply of the target material to 800Hz, the voltage of a bias power supply to 700V and the rotating speed of a rotary table to 2min/r, and starting the target material to bombard for 30 min; then reducing the voltage of a bias power supply to 90V, and starting the target material to sputter for 30 min;

changing the targets into a titanium-aluminum target and a silicon-titanium target, vacuumizing, introducing argon and nitrogen to ensure that the partial pressure of the argon is 250MPa, the partial pressure of the nitrogen is 460MPa, the introduction flow of the nitrogen is 90sccm, setting the voltage of a bias power supply to be 90V, adjusting the power of the target to be 9000kW, and starting the target to sputter for 4.5 hours; and (5) cooling to obtain the product.

Example 4

The composite coating cutter comprises a cutter base body, a diamond layer and a nitride layer, wherein the diamond layer and the nitride layer are sequentially arranged from the surface of the cutter base body to the outside; the thickness of the diamond layer is 15 μm, and the thickness of the nitride layer is 6 μm; the nitride layer is made of a nitride of Ti₃Si_0.3Al₃N_x。

2) mixing sulfuric acid and hydrogen peroxide according to a volume ratio of 3:7 to obtain a pickling solution, putting the cutter substrate washed in the step 1) into the pickling solution, soaking for 40s for decobalting, taking out, and putting into deionized water for ultrasonic treatment for 90min for washing; the mass fraction of the adopted sulfuric acid is 97 percent, and the mass fraction of the hydrogen peroxide is 50 percent;

4) depositing a diamond film on the surface of the cutter substrate washed in the step 3) by adopting a hot wire CVD method to form a diamond layer, and preparing a diamond coated cutter; deposition by hot filament CVD with H₂And CH₄As a reaction source, the deposition time is 15h under the conditions that the pressure is 1kPa and the temperature is 800 ℃;

using Ti as a target material, setting the power supply power of the target material to be 2000kW, setting the pulse frequency of the power supply of the target material to be 500Hz, the voltage of a bias power supply to be 800V and the rotating speed of a rotary table to be 3min/r, and starting the target material to bombard for 30 min;

changing the target materials into a titanium-aluminum target material and a silicon-titanium target material, vacuumizing, introducing argon and nitrogen to ensure that the partial pressure of the argon is 250MPa, the partial pressure of the nitrogen is 500MPa, the introduction flow of the nitrogen is 100sccm, setting the voltage of a bias power supply to be 80V, adjusting the power supply power of the target materials to be 8000kW, and starting the target materials to sputter for 7 hours; and (5) cooling to obtain the product.

Example 5

The composite coated cutting tool of the embodiment comprisesThe cutting tool comprises a cutting tool base body, and a diamond layer, a titanium carbide (TiC) transition layer, a titanium metal layer and a nitride layer which are sequentially arranged from the surface of the cutting tool base body to the outside; the thickness of the diamond layer is 3 μm, the thickness of the titanium carbide transition layer is 0.01 μm, the thickness of the titanium metal layer is 0.2 μm, and the thickness of the nitride layer is 6 μm; the nitride layer is made of nitride, the nitride is TiSi_0.05Al₃N_x。

1) mixing potassium ferricyanide, a hydrogen oxidant and deionized water according to the mass ratio of 1:1.2:9 to obtain an alkaline solution, then putting the cutter substrate into the alkaline solution for ultrasonic treatment for 20min, taking out, and putting into the deionized water for ultrasonic treatment for 5min to wash;

2) mixing sulfuric acid and hydrogen peroxide according to a volume ratio of 3:7 to obtain a pickling solution, putting the cutter substrate washed in the step 1) into the pickling solution, soaking for 40s for decobalting, taking out, and putting into deionized water for ultrasonic treatment for 70min for washing; the mass fraction of the adopted sulfuric acid is 97 percent, and the mass fraction of the hydrogen peroxide is 30 percent;

3) putting the cutter substrate washed in the step 2) into the nano-diamond suspension for ultrasonic treatment for 40min, taking out, and putting into deionized water for ultrasonic treatment for 2min for washing; the particle size of the nano diamond is 20 nm;

4) depositing a diamond film on the surface of the cutter substrate washed in the step 3) by adopting a hot wire CVD method to form a diamond layer, and preparing a diamond coated cutter; deposition by hot filament CVD with H₂And CH₄As a reaction source, the deposition time is 4h under the conditions that the pressure is 1.4kPa and the temperature is 1200 ℃;

5) mechanically blasting the diamond layer of the diamond coating cutter in the step 4), wherein the medium for blasting is alumina, the pressure is 3.2MPa, and the time is 12 min; washing for 1h by using deionized water after sand blasting treatment;

6) placing the diamond coating cutter washed in the step 5) in a cavity of a magnetron sputtering coating machine, and vacuumizing to 1 x 10^-3Pa, and heated to 500 ℃ with a flow of 80sccmIntroducing argon, setting the voltage of a bias power supply to be 1000V, and carrying out glow discharge cleaning on the diamond coating cutter for 40 min;

using Ti as a target material, setting the power supply power of the target material to be 2000kW, the pulse frequency of the power supply of the target material to be 900Hz, the voltage of a bias power supply to be 800V and the rotating speed of a rotary table to be 2min/r, and starting the target material to bombard for 25 min; then reducing the voltage to 100V, and starting the target material to sputter for 25 min;

changing the target materials into a titanium-aluminum target material and a silicon-titanium target material, vacuumizing, introducing argon and nitrogen to ensure that the partial pressure of the argon is 250MPa, the partial pressure of the nitrogen is 400MPa, the introduction flow of the nitrogen is 80sccm, setting the voltage of a bias power supply to 100V, adjusting the power of the target material to 8000kW, and starting the target material to sputter for 7 hours; and (5) cooling to obtain the product.

Example 6

The composite coating cutter comprises a cutter base body, and a diamond layer, a titanium carbide (TiC) transition layer, a titanium metal layer and a nitride layer which are sequentially arranged from the surface of the cutter base body to the outside; the thickness of the diamond layer is 15 microns, the thickness of the titanium carbide transition layer is 0.03 microns, the thickness of the titanium metal layer is 0.16 microns, and the thickness of the nitride layer is 2 microns; the nitride layer is composed of a nitride of Zr₃Si_0.05Al₃CrN_x。

1) mixing potassium ferricyanide, a hydrogen oxidant and deionized water according to the mass ratio of 1:0.9:101 to obtain an alkaline solution, then putting the cutter substrate into the alkaline solution for ultrasonic treatment for 30min, taking out the cutter substrate, and putting the cutter substrate into the deionized water for ultrasonic treatment for 8min to wash;

2) mixing sulfuric acid and hydrogen peroxide according to a volume ratio of 3:7 to obtain a pickling solution, soaking the cutter substrate washed in the step 1) in the pickling solution for 30s to remove cobalt, taking out, and placing in deionized water for ultrasonic treatment for 80min to wash; the mass fraction of the adopted sulfuric acid is 97 percent, and the mass fraction of the hydrogen peroxide is 30 percent;

3) putting the cutter substrate washed in the step 2) into the nano-diamond suspension for ultrasonic treatment for 35min, taking out, and putting into deionized water for ultrasonic treatment for 5min for washing; the particle size of the nano diamond is 30 nm;

4) depositing a diamond film on the surface of the cutter substrate washed in the step 3) by adopting a hot wire CVD method to form a diamond layer, and preparing a diamond coated cutter; deposition by hot filament CVD with H₂And CH₄As a reaction source, the deposition time is 17 hours under the conditions that the pressure is 2.0kPa and the temperature is 900 ℃;

5) mechanically blasting the diamond layer of the diamond coating cutter in the step 4), wherein the medium for blasting is alumina, the pressure is 3.8MPa, and the time is 15 min; washing for 1h by using deionized water after sand blasting treatment;

6) placing the diamond coating cutter washed in the step 5) in a cavity of a magnetron sputtering coating machine, and vacuumizing to 1 x 10^-3Pa, heating to 500 ℃, introducing argon at the flow of 80sccm, setting the bias power voltage to 1100V, and performing glow discharge cleaning on the diamond coating cutter for 180 min;

using Ti as a target material, setting the power supply power of the target material to be 2000kW, the pulse frequency of the power supply of the target material to be 1000Hz, the voltage of a bias power supply to be 800V and the rotating speed of a rotary table to be 3min/r, and starting the target material to bombard for 35 min; then, the voltage of a bias power supply is reduced to 80V, and the target is started to sputter for 35 min;

changing the target materials into a zirconium-aluminum target material, a zirconium-silicon target material and a chromium-aluminum target material, vacuumizing, introducing argon and nitrogen to ensure that the partial pressure of the argon is 300MPa, the partial pressure of the nitrogen is 600MPa, the introduction flow of the nitrogen is 150sccm, setting the voltage of a bias power supply to be 100V, adjusting the power of the target material to be 10000kW, and starting the target material to sputter for 2.5 hours; and (5) cooling to obtain the product.

Comparative example 1

The cutter of this comparative example was a YG6 cemented carbide insert, gauge VNGA 160404.

Comparative example 2

The tool of this comparative example was the diamond coated tool made in example 1.

Experimental example 1

The composite coated cutters of examples 1-6 were tested for nitride and diamond bond strength using the scratch method and the results are shown in table 1.

TABLE 1 bonding strength of nitride and diamond of composite coated cutting tools of examples 1-6

	Example 1	Example 2	Example 3	Example 4	Example 5	Example 6
							Bonding Strength/N	50	75	110	15	5	80

As can be seen from the data in table 1, the provision of a titanium metal layer and a titanium carbide transition layer between the diamond layer and the nitride layer enhances the bond strength of the diamond layer and the nitride layer.

Experimental example 2

The service life of the gray cast iron was tested by using the cutting tools of examples 1 to 6 and comparative examples 1 to 2, and the test results are shown in table 2. The diameter of the gray cast iron workpiece used for the test was 280mm, the cast iron was of grade HT250, and the hardness was HB 190; the processing parameters during the test were: cutting speed 440m/min, feed rate 0.23mm/min, cutting depth 0.5mm, surface roughness of the processed piece Ra1.6, and processing time 50 s.

TABLE 2 results of testing the service lives of the cutting tools of examples 1 to 6 and comparative examples 1 to 2

	Example 1	Example 2	Example 3	Example 4	Example 5	Example 6	Comparative example 1	Comparative example 2
									Number of workpieces/edge	13	40	45	12	11	38	6	3

As can be seen from the data in table 2, the diamond containing composite coated tool can effectively process gray cast iron material. The cobalt removal time of the tool substrate in the preparation process of the composite coating tool in the embodiment 1 is relatively short, Co cannot be effectively removed, and the diamond is deposited on the tool substrate, so that more gaps exist at the interface of the tool substrate and the diamond, and the substrate coating is easy to fall off, so that the service life of the tool is influenced; in the composite coated cutting tool of example 4, the nitride layer and the diamond layer are lack of compounds such as carbide and the like, and chemical bonding is not formed, so that the bonding between the nitride and the diamond is poor, the coating is easy to fall off, and the service life of the cutting tool is shortened. The composite coated cutters of examples 2 and 3 had closer test results and better performance because the bond between the coating and the substrate, and between the coating and the coating, was better, and because the diamond layer of the composite coated cutter of example 3 was thicker, the hardness of the coating was higher, and the wear resistance was better than that of example 2. Example 5 the coating was relatively soft and the wear resistance decreased due to the higher Al content. In example 6, Zr replaces Ti, and the performance is approximately the same as that of Ti compound. Comparative examples 1 and 2 are slightly inferior.

Experimental example 3

The quenched steels of examples 1 to 6 and comparative examples 1 to 2 were used for testing the service life, and the test results are shown in table 3. The quenched steel used for the test was GCr15 bearing quenched steel with hardness HRC 58-60. The processing parameters during the test were: the cutting speed is 146m/min, the feed rate is 0.12mm/min, the cutting depth is 0.15mm, the surface roughness Ra of a workpiece is 1.6, and the processing time is 60 s.

TABLE 3 results of testing the service lives of the cutting tools of examples 1 to 6 and comparative examples 1 to 2

	Example 1	Example 2	Example 3	Example 4	Example 5	Example 6	Comparative example 1	Comparative example 2
									Number of workpieces/edge	22	100	120	15	11	98	18	0

As can be seen from the data in Table 3, when the quenched steel workpiece of the GCr15 bearing is processed, the diamond coating tool fails to process the quenched steel workpiece due to the high temperature failure of the cutting edge. Compared with an uncoated hard alloy blade, the diamond coating tool processing performance of the composite nitride layer is obviously improved. The composite coated cutting tools of examples 1-6 exhibited substantially the same performance and tendency as machined gray cast iron immediately after machining and quenching.

Claims

1. A composite coated cutting tool, characterized in that: the preparation method of the composite coating cutter comprises the following steps:

sequentially carrying out alkali washing, cobalt removal and seed crystal seeding on the cutter substrate, and then depositing a diamond layer on the cutter substrate to obtain a diamond coated cutter; carrying out sand blasting treatment, glow discharge cleaning and ion etching on a diamond layer of the diamond coating cutter in sequence; then depositing titanium metal on the diamond coated cutter, and sequentially forming a titanium carbide layer and a titanium metal layer in the direction away from the diamond coated cutter; finally, depositing nitride to form a nitride layer;

the cutter base body is made of hard alloy;

the method for seeding the seeds comprises the following steps: putting the decobalted cutter substrate into a nano-diamond suspension for ultrasonic treatment, wherein the particle size of the nano-diamond is 20-60 nm;

depositing titanium metal on the diamond coating cutter by adopting a pulse magnetron sputtering method, wherein the pulse magnetron sputtering method comprises the steps of controlling the temperature to be 500-550 ℃, the bias power supply voltage to be 70-100V, the pulse frequency of a target power supply to be 500-1000 Hz, the power supply power of the target to be 2000-3000 kW, and sputtering for 25-35 min in an argon atmosphere, wherein the target is a Ti target;

the deposited nitride is sputtered for 2.5-7 hours by adopting a pulse magnetron sputtering method, wherein the pulse magnetron sputtering method is to sputter for 2.5-7 hours in a mixed atmosphere of nitrogen and argon, the temperature is controlled to be 500-550 ℃, the bias power supply voltage is 70-100V, the pulse frequency of a target power supply is 500-1000 Hz, and the power of the target power supply is 8000-10000 kW.

2. The composite coated cutting tool according to claim 1, wherein: the thickness of the titanium metal layer is 0.01-0.2 μm, and the thickness of the titanium carbide layer is 0.01-0.1 μm.

3. The composite coated cutting tool according to claim 1, wherein: the nitride layer is composed of a nitride; the nitride is composed of at least one element of Ti, Si, Al, Cr and Zr and N element.

4. The composite coated cutting tool according to claim 3, wherein: the nitride consists of Ti, Si, Al and N elements; the atomic molar ratio of Ti, Si and Al in the nitride is 1-3: 0.05-0.3: 2-3.

5. The composite coated cutting tool according to claim 1, wherein: the thickness of the nitride layer is 2-6 mu m; the thickness of the diamond layer is 3-15 mu m.

6. A method of making a composite coated cutting tool according to claim 1, characterized in that: the method comprises the following steps: depositing nitride on the diamond coating cutter to form a nitride layer; the diamond coated cutting tool comprises a cutting tool base body and a diamond layer coated on the cutting tool base body;

the preparation method of the diamond-coated cutter comprises the following steps: sequentially carrying out alkali washing, cobalt removal and seed crystal seeding on the cutter substrate, and then depositing a diamond layer on the cutter substrate to obtain the cutting tool; the cutter base body is made of hard alloy;

before depositing nitride on the diamond coated cutter, firstly depositing titanium metal on the diamond coated cutter, and sequentially forming a titanium carbide layer and a titanium metal layer in the direction away from the diamond coated cutter;

before depositing titanium metal on the diamond coating cutter, carrying out sand blasting treatment, glow discharge cleaning and ion etching on a diamond layer of the diamond coating cutter in sequence;