High-binding-force titanium nitride coating and preparation method thereof

Abstract

The invention relates to the technical field of preparation of high-binding-force titanium nitride coatings, in particular to a high-binding-force titanium nitride coating and a preparation method thereof.The preparation method comprises the steps that S1, a tool base body is pretreated; s2, carrying out glow cleaning treatment by adopting high-power pulse magnetron sputtering equipment; s3, high-purity argon is stopped from being introduced into the vacuum chamber, the vacuum degree in the vacuum chamber is adjusted to be 0.003 Pa or below, then N2 gas is continuously introduced into the vacuum chamber, high-purity argon is continuously introduced again, the pressure of the vacuum chamber is controlled to be 0.3-0.8 Pa, a high-power pulse power source is used for sputtering a T target, and a titanium nitride coating is deposited on the tool base body; and S4, after deposition is completed, the tool base body is taken out after being cooled to 100 DEG C or below along with the furnace. According to the preparation method, the element ratio in the coating is adjusted by adjusting and controlling technological parameters in the preparation process, the bonding performance of the coating is improved, and it is guaranteed that the coating still keeps high bonding force under the high-temperature and high-speed cutting conditions.

Description

Technical Field

[0001] The invention relates to the technical field of high-bonding strength titanium nitride coating preparation, and in particular to a high-bonding strength titanium nitride coating and a preparation method thereof. Background Art

[0002] A tool usually refers to a tool with a sharp edge, which is used to cut, strip or pierce objects; in the industrial field, tools are usually used in the cutting process to process the surface, end face, inner hole of the workpiece, process the surface of complex shapes, cut off the workpiece or perform grooving, etc. However, during the cutting process, there is a large friction and wear between the workpiece and the tool, which greatly shortens the service life of the tool; and the friction between the workpiece and the tool will also generate a large amount of cutting heat, especially in high temperature and high speed cutting environments, which will cause the hardness and strength of the tool to decrease, and will also make the tool surface prone to oxidation and corrosion, affecting the service life of the tool, increasing the frequency of tool replacement, and increasing the cutting cost. Tool coating technology is to coat one or more layers of wear-resistant, high temperature-resistant and oxidation-resistant coatings on the surface of the tool base material; the coating acts as a chemical barrier and thermal barrier, which can reduce the friction coefficient between the tool and the workpiece, thereby reducing cutting force and cutting heat, improving the cutting performance and cutting efficiency of the tool, and reducing tool wear. It has been widely used in the cutting tool industry.

[0003] Titanium nitride (T i N) coating is golden yellow in color, has good hardness and chemical stability, and is widely used as a tool coating. It can reduce the friction between the workpiece and the tool, extend the tool life, and is suitable for processing low-alloy steel and stainless steel. However, the cutting temperature increases sharply with the increase of cutting speed, and the difference in lattice constant and thermal expansion coefficient between the coating and the substrate leads to poor bonding between the coating and the substrate, making the coating easy to peel off under high temperature conditions, thereby affecting the service life of the coating and the tool. Therefore, it is urgent to develop a titanium nitride coating with high bonding strength.

[0004] The invention provides a high-bonding strength titanium nitride coating and a preparation method thereof, so as to solve the problem in the prior art that the existing titanium nitride coating has poor bonding strength with a substrate under high temperature conditions. Summary of the invention

[0005] The purpose of the present invention is to provide a high-bonding strength titanium nitride coating and a preparation method thereof, so as to solve the problem that the existing titanium nitride coating in the prior art has poor bonding strength with a substrate under high temperature conditions.

[0006] The technical solution of the present invention is: a method for preparing a titanium nitride coating with high bonding strength, comprising the following steps: S1, pre-treating a tool substrate; the pre-treatment comprises ultrasonic cleaning and drying;

[0007] S2. Use high-power pulse magnetron sputtering equipment to perform glow cleaning on the pretreated tool substrate; the glow cleaning process includes the following steps: a. Place the pretreated tool substrate into the vacuum chamber of the high-power pulse magnetron sputtering equipment, and adjust the pressure in the vacuum chamber to 0.003Pa or below; b. Continuously introduce high-purity argon gas into the vacuum chamber, and then adjust the pressure of the vacuum chamber to within the range of 1 to 2Pa; c. Adjust the voltage of the bias power supply to within the range of -500 to -1500V, and reversely clean the tool substrate under the condition that the negative bias duty cycle is 30 to 80%, and the cleaning time is 10 to 30min;

[0008] S3. After the cleaning is completed, stop introducing high-purity argon gas into the vacuum chamber, and adjust the vacuum degree in the vacuum chamber to 0.003Pa or less. Then, continue to introduce N2 gas into the vacuum chamber, and continue to introduce high-purity argon gas again, control the pressure of the vacuum chamber to be in the range of 0.3-0.8Pa, and use a high-power pulse power supply to sputter the Ti target under the deposition conditions of substrate temperature of 300-500°C, bias voltage of -20--200V, and negative bias duty cycle of 20-80%, to deposit a titanium nitride coating on the tool substrate;

[0009] S4. After the deposition is completed, the high-power pulse power supply is turned off, and the tool substrate is taken out after cooling down to below 100° C. in the furnace to obtain a tool substrate with a titanium nitride coating on the surface.

[0010] Preferably, the thickness of the titanium nitride coating is 200-1000 nm; and the film-base bonding strength of the titanium nitride coating is not less than 100N.

[0011] Preferably, in step S3, the power of the high-power pulse power supply during the sputtering of the Ti target is 3000-7000W.

[0012] Preferably, in step S1, the ultrasonic cleaning includes sequentially placing the tool substrate into a cleaning agent for ultrasonic cleaning, placing it into acetone for ultrasonic cleaning, and placing it into an alcohol solution for ultrasonic cleaning; and the drying treatment is performed in a drying oven.

[0013] Preferably, the purity of the Ti target is 99.9%; in the Ti target, the atomic ratio of Ti to Al is 1:1.

[0014] Preferably, the purity of the high-purity argon gas and the N2 gas is 99.99%.

[0015] The present application also provides a high-bonding titanium nitride coating, which is prepared using the above-mentioned preparation method.

[0016] Preferably, calculated by atomic percentage, the composition of the titanium nitride coating includes 30-60 at. % of Ti element and 40-70 at. % of N element.

[0017] Compared with the prior art, the advantages of the present invention are:

[0018] (1) The present invention provides a high-bonding strength titanium nitride coating and a preparation method thereof. The preparation method of the high-bonding strength titanium nitride coating is to control the growth mode of the titanium nitride coating by regulating the process parameters in the preparation process of the titanium nitride coating, and to adjust the Ti and N element ratios in the titanium nitride coating, thereby reducing the differences in lattice constants and thermal expansion coefficients between the titanium nitride coating and the tool substrate, thereby improving the bonding performance of the titanium nitride coating, ensuring that the titanium nitride coating still maintains a high bonding strength under high temperature and high-speed cutting conditions, extending the service life of the titanium nitride coating and the tool, effectively reducing the replacement frequency of the tool, and saving the cost of the cutting process; at the same time, by adjusting the Ti and N element ratios in the titanium nitride coating, the surface roughness of the titanium nitride coating can also be reduced to below 20 nm, which not only helps to improve the surface quality of the titanium nitride coating, significantly improves the hardness of the tool, and enhances the wear resistance of the tool; it can also reduce the friction coefficient between the workpiece and the tool, reduce the influence of heat generation, and effectively improve the cutting speed and processing efficiency; and solves the problem of poor bonding between the existing titanium nitride coating and the substrate under high temperature conditions in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0020] Figure 1 This is a cross-sectional SEM image of the titanium nitride coating prepared in Example 1 of the present invention;

[0021] Figure 2 The results of the test on the bonding performance of the titanium nitride coating prepared in Example 1 of the present invention;

[0022] Figure 3 This is a scratch morphology image of the titanium nitride coating prepared in Example 1 of the present invention;

[0023] Figure 4 The results of the test on the bonding performance of the titanium nitride coating prepared in Example 2 of the present invention;

[0024] Figure 5 This is a scratch morphology image of the titanium nitride coating prepared in Example 2 of the present invention;

[0025] Figure 6 This is a cross-sectional SEM image of the titanium nitride coating prepared in Example 3 of the present invention. DETAILED DESCRIPTION

[0026] The present invention is further described in detail below in conjunction with specific embodiments:

[0027] It should be noted that the test methods described in the following examples are conventional methods unless otherwise specified; the reagents and materials used are commercially available unless otherwise specified.

[0028] It should be noted that the preparation method of the titanium nitride coating provided in the present application is applicable to a tool substrate; and the material of the tool substrate is a conventional material involved in the field; for example, high-speed steel, cemented carbide, or high-speed steel or cemented carbide provided with polycrystalline cubic boron nitride, diamond, or ceramic.

[0029] In the present application, in the following embodiments, the tool substrate used is a cemented carbide WC-10% Co tool; the cleaning agent used is a commercially available cemented carbide cleaning agent, trade name Anticorplus cleaning agent (Swiss Deconex Company); in other embodiments, the tool substrate can be made of other types of cemented carbide materials; the cleaning agent can also be of other brands and models. The high-power pulsed magnetron sputtering equipment used in the following embodiments is purchased on the market, the model is JGP500D1, JCP350 or VTC-600-2HD; in other embodiments, other models of high-power pulsed magnetron sputtering equipment sold on the market can be used.

[0030] In the present application, the standard adopted for the bonding strength test is the national standard JB / T 8554-1997; in the following embodiments, the equipment used to observe the surface morphology of the coating is a metallographic microscope, model Ollympus DSX 500; the equipment used to observe the cross-sectional morphology of the coating is a scanning electron microscope (UltraPlus, Zeiss); other models of metallographic microscopes and scanning electron microscopes available on the market can be used to observe the surface of the coating, etc.

[0031] Example 1

[0032] The method for preparing a high-bonding titanium nitride coating provided in the present application is used to prepare a tool substrate having a titanium nitride coating with a coating thickness of 140 nm; wherein the titanium nitride coating comprises Ti and N; and, calculated by atomic percentage, the titanium nitride coating comprises 30 at.% of Ti element and 70 at.% of N element. The specific preparation method is as follows:

[0033] S1. Pre-treat the tool substrate; first put the tool substrate into a cleaning agent for ultrasonic cleaning for about 10 minutes; then put the tool substrate into acetone for ultrasonic cleaning for about 15 minutes; then, put the tool substrate into an alcohol solution for ultrasonic cleaning for about 10 minutes; after the ultrasonic cleaning is completed, take the tool substrate out of the alcohol solution; then put the tool substrate into a drying box, slowly increase the temperature in the drying box, and dry the blade substrate.

[0034] S2. Use high-power pulse magnetron sputtering equipment to perform glow cleaning on the pretreated tool substrate; first, place the pretreated tool substrate into the vacuum chamber of the high-power pulse magnetron sputtering equipment, and adjust the pressure in the vacuum chamber to 0.003Pa or below; then, continuously introduce high-purity argon gas into the vacuum chamber; then, adjust the pressure of the vacuum chamber to within 2Pa; then, adjust the voltage of the bias power supply to -500V, and reverse clean the tool substrate under the condition of a negative bias duty cycle of 80%, and the cleaning time is 10min;

[0035] S3. After the cleaning is completed, stop introducing high-purity argon gas into the vacuum chamber, and adjust the vacuum degree in the vacuum chamber to 0.003Pa or below; then, continue to introduce N2 gas into the vacuum chamber, and continue to introduce high-purity argon gas again, and adjust the flow rate of N2 gas to 20sccm, and the flow rate of high-purity argon gas to 200sccm; control the pressure of the vacuum chamber within the range of 0.5Pa, under the deposition conditions of substrate temperature of 400°C, bias voltage of -120V, and negative bias duty cycle of 20%, use a high-power pulse power supply to sputter Ti target, and deposit titanium nitride coating on the tool substrate;

[0036] S4. After the deposition is completed, turn off the high-power pulse power supply, etc., and cool the tool substrate with the furnace to below 100°C after cooling with the furnace for 90 to 150 minutes. Then take out the tool substrate to obtain a tool substrate with a titanium nitride coating on the surface.

[0037] Example 2

[0038] The method for preparing a high-bonding titanium nitride coating provided in the present application is used to prepare a tool substrate having a titanium nitride coating with a coating thickness of 1000 nm; wherein the titanium nitride coating comprises Ti and N; and, calculated by atomic percentage, the titanium nitride coating comprises 60 at.% of Ti element and 40 at.% of N element. The specific preparation method is as follows:

[0039] S1. Pre-treat the tool substrate; first put the tool substrate into a cleaning agent for ultrasonic cleaning for about 10 minutes; then put the tool substrate into acetone for ultrasonic cleaning for about 15 minutes; then, put the tool substrate into an alcohol solution for ultrasonic cleaning for about 10 minutes; after the ultrasonic cleaning is completed, take the tool substrate out of the alcohol solution; then put the tool substrate into a drying box, slowly increase the temperature in the drying box, and dry the blade substrate.

[0040] S2. Use high-power pulse magnetron sputtering equipment to perform glow cleaning on the pretreated tool substrate; first, place the pretreated tool substrate into the vacuum chamber of the high-power pulse magnetron sputtering equipment, and adjust the pressure in the vacuum chamber to 0.003Pa or below; then, continuously introduce high-purity argon gas into the vacuum chamber; then, adjust the pressure of the vacuum chamber to within 1.5Pa; then, adjust the voltage of the bias power supply to -500V, and reverse clean the tool substrate under the condition of a negative bias duty cycle of 80%, and the cleaning time is 20min;

[0041] S3. After the cleaning is completed, stop introducing high-purity argon gas into the vacuum chamber, and adjust the vacuum degree in the vacuum chamber to 0.003Pa or below; then, continue to introduce N2 gas into the vacuum chamber, and continue to introduce high-purity argon gas again, and adjust the flow rate of N2 gas to 20sccm, and the flow rate of high-purity argon gas to 200sccm; control the pressure of the vacuum chamber within the range of 0.5Pa, under the deposition conditions of substrate temperature of 400°C, bias voltage of -200V, and negative bias duty cycle of 40%, use a high-power pulse power supply to sputter Ti target, and deposit titanium nitride coating on the tool substrate, and the deposition time is 60min;

[0042] S4. After the deposition is completed, turn off the high-power pulse power supply, etc., and cool the tool substrate with the furnace to below 100°C after cooling with the furnace for 90 to 150 minutes. Then take out the tool substrate to obtain a tool substrate with a titanium nitride coating on the surface.

[0043] Example 3

[0044] The method for preparing the high-bonding titanium nitride coating provided in the present application is used to prepare a tool substrate having a coating thickness the same as that of Example 2; and, calculated by atomic percentage, the titanium nitride coating includes 65 at.% Ti element and 35 at.% N element. The specific preparation method is as follows:

[0045] S1. Pre-treat the tool substrate; first put the tool substrate into a cleaning agent for ultrasonic cleaning for about 10 minutes; then put the tool substrate into acetone for ultrasonic cleaning for about 15 minutes; then, put the tool substrate into an alcohol solution for ultrasonic cleaning for about 10 minutes; after the ultrasonic cleaning is completed, take the tool substrate out of the alcohol solution; then put the tool substrate into a drying box, slowly increase the temperature in the drying box, and dry the blade substrate.

[0046] S2. Use high-power pulse magnetron sputtering equipment to perform glow cleaning on the pretreated tool substrate; first, place the pretreated tool substrate into the vacuum chamber of the high-power pulse magnetron sputtering equipment, and adjust the pressure in the vacuum chamber to 0.003Pa or below; then, continuously introduce high-purity argon gas into the vacuum chamber; then, adjust the pressure of the vacuum chamber to within 1.5Pa; then, adjust the voltage of the bias power supply to -500V, and reverse clean the tool substrate under the condition of a negative bias duty cycle of 80%, and the cleaning time is 20min;

[0047] S3. After the cleaning is completed, stop introducing high-purity argon gas into the vacuum chamber, and adjust the vacuum degree in the vacuum chamber to 0.003Pa or below; then, continue to introduce N2 gas into the vacuum chamber, and continue to introduce high-purity argon gas again, and adjust the flow rate of N2 gas to 30sccm, and the flow rate of high-purity argon gas to 190sccm; control the pressure of the vacuum chamber within the range of 0.5Pa, under the deposition conditions of substrate temperature of 400°C, bias voltage of -40V, and negative bias duty cycle of 70%, use a high-power pulse power supply to sputter Ti target, and deposit titanium nitride coating on the tool substrate;

[0048] S4. After the deposition is completed, turn off the high-power pulse power supply, etc., and cool the tool substrate with the furnace to below 100°C after cooling with the furnace for 90 to 150 minutes. Then take out the tool substrate to obtain a tool substrate with a titanium nitride coating on the surface.

[0049] The titanium nitride coatings prepared in Example 1 and Example 2 were tested using scanning electron microscopes, metallographic microscopes and other equipment, and the test results of the titanium nitride coatings prepared in Example 1, Example 2 and Example 3 were compared. It can be seen from the cross-sectional SEM test results of the prepared titanium nitride coating that Figure 1 , Figure 6As shown, the titanium nitride coating prepared in Example 1 and the titanium nitride coating prepared in Example 3 have a surface roughness of less than 20 nm; and, compared with the titanium nitride coating prepared in Example 1, the surface of the titanium nitride coating prepared in Example 3 is more uniform and smooth; further illustrating that by regulating the process parameters in the preparation process of the titanium nitride coating, for example, regulating the flow rate of N2 gas, the flow rate of high-purity argon gas, the bias voltage, and the negative bias voltage duty cycle, etc., the growth mode of the titanium nitride coating can be regulated, and then the Ti and N element ratio in the titanium nitride coating can be adjusted to reduce the surface roughness of the titanium nitride coating to less than 20 nm, thereby effectively improving the surface quality of the titanium nitride coating; it can be seen from the acoustic signal detection results of the prepared titanium nitride coating that, Figure 2 , Figure 4 As shown, compared with the titanium nitride coating prepared in Example 1, the titanium nitride coating prepared in Example 2 has a higher bonding strength with the tool substrate, and the titanium nitride coating prepared in Example 2 has more excellent bonding performance; it is further explained that by regulating the process parameters in the preparation process of the titanium nitride coating to regulate the growth mode of the titanium nitride coating, thereby adjusting the Ti and N element ratio in the titanium nitride coating, the bonding performance of the titanium nitride coating can be improved and the wear resistance of the tool can be enhanced; at the same time, the difference in lattice constant and thermal expansion coefficient between the titanium nitride coating and the tool substrate can be reduced, ensuring that the titanium nitride coating still maintains a high bonding force under high temperature and high-speed cutting conditions, which helps to extend the service life of the titanium nitride coating and the tool, effectively reduce the replacement frequency of the tool, and save cutting processing costs; from the scratch morphology detection results of the prepared titanium nitride coating, it can be seen that Figure 3 , Figure 5 As shown, compared with the titanium nitride coating prepared in Example 1, the titanium nitride coating prepared in Example 2 has more excellent wear resistance; further illustrating that by adjusting the process parameters in the preparation process of the titanium nitride coating, the hardness of the tool can be significantly improved and the wear resistance of the tool can be enhanced. In addition, the preparation method of the titanium nitride coating provided in the present application can be applied to a magnetron sputtering device with a multi-target co-sputtering function; it helps to expand its scope of use.

[0050] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the scope of protection of the present invention. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is limited by the attached claims rather than the above description, and it is intended to include all changes within the meaning and scope of the equivalent elements of the claims in the present invention.

Claims

1. A method for preparing a high-bonding titanium nitride coating, characterized in that: The following steps are involved: S1, pre-treating the tool substrate; the pre-treatment includes ultrasonic cleaning and drying; S2. Use high-power pulse magnetron sputtering equipment to perform glow cleaning on the pretreated tool substrate; the glow cleaning process includes the following steps: a. Place the pretreated tool substrate into the vacuum chamber of the high-power pulse magnetron sputtering equipment, and adjust the pressure in the vacuum chamber to 0.003Pa or below; b. Continuously introduce high-purity argon gas into the vacuum chamber, and then adjust the pressure of the vacuum chamber to within the range of 1 to 2Pa; c. Adjust the voltage of the bias power supply to within the range of -500 to -1500V, and reversely clean the tool substrate under the condition that the negative bias duty cycle is 30 to 80%, and the cleaning time is 10 to 30min; S3. After the cleaning is completed, stop introducing high-purity argon gas into the vacuum chamber, and adjust the vacuum degree in the vacuum chamber to 0.003Pa or below. Then, continue to introduce N2 gas into the vacuum chamber, and continue to introduce high-purity argon gas again, control the pressure of the vacuum chamber to be in the range of 0.3-0.8Pa, and use a high-power pulse power supply to sputter the Ti target material under the deposition conditions of substrate temperature of 300-500°C, bias voltage of -20--200V, and negative bias duty cycle of 20-80%, and deposit a titanium nitride coating on the tool substrate; S4. After the deposition is completed, the high-power pulse power supply is turned off, and the tool substrate is taken out after cooling down to below 100° C. in the furnace to obtain a tool substrate with a titanium nitride coating on the surface.

2. The method for preparing a high-bonding titanium nitride coating according to claim 1, characterized in that: The thickness of the titanium nitride coating is 200-1000nm; the film-base bonding force of the titanium nitride coating is not less than 100N.

3. The method for preparing a high-bonding titanium nitride coating according to claim 2, characterized in that: In step S1, the ultrasonic cleaning process includes sequentially placing the tool substrate into a cleaning agent for ultrasonic cleaning, placing it into acetone for ultrasonic cleaning, and placing it into an alcohol solution for ultrasonic cleaning; the drying process is performed in a drying oven.

4. The method for preparing a high-bonding titanium nitride coating according to claim 2, characterized in that: In step S3, the power of the high-power pulse power supply during the sputtering of the Ti target is 3000-7000W.

5. The method for preparing a high-bonding titanium nitride coating according to claim 2, characterized in that: The purity of the Ti target material is 99.9%; in the Ti target material, the atomic ratio of Ti to Al is 1:

1.

6. The method for preparing a high-bonding titanium nitride coating according to claim 2, characterized in that: The purity of the high-purity argon gas and the N2 gas are both 99.99%.

7. A high-bonding titanium nitride coating, characterized in that: The titanium nitride coating is prepared by the preparation method described in any one of claims 1 to 6.

8. The high-bonding titanium nitride coating according to claim 7, characterized in that: Calculated by atomic percentage, the titanium nitride coating comprises 30 to 60 at. % of Ti element and 40 to 70 at. % of N element.

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