CN114672779A - A kind of preparation method of TiB2/Ti composite coating - Google Patents

Abstract

The invention discloses a TiB₂A preparation method of a/Ti composite coating belongs to the technical field of material surface modification and thin film material preparation. The preparation method of the coating comprises the following steps: (1) pre-treating a substrate material; (2) pre-sputtering: carrying out pre-sputtering treatment on a substrate material and a target material; (3) depositing a Ti transition layer on the substrate material by adopting a direct-current magnetron sputtering method to obtain the substrate material with the Ti transition layer; (4) using a direct current pulse magnetron sputtering method to form a Ti film on the surface of the substrateDepositing target material on the base material of the transition layer to obtain TiB₂A hard protective layer, i.e. said TiB₂a/Ti composite coating. The coating prepared by the invention is flat and compact in structure, has no impurity problem in deposition under a vacuum condition, has higher compactness and lower porosity, has extremely high hardness and wear resistance, and simultaneously has excellent corrosion resistance and conductivity compared with other technologies.

Description

A kind of preparation method of TiB2/Ti composite coating

technical field

The invention relates to the technical field of material surface modification and thin film material preparation, in particular to a preparation method of a TiB ₂ /Ti composite coating.

Background technique

At present, my country's integrated circuit industry is in a period of rapid development, and the requirements for related manufacturing industries are constantly increasing. Among them, the processing of PCB printed circuit boards is a crucial part. Micro drill is the main part of PCB circuit board processing, it is very important to improve the service life and quality of micro drill. Titanium diboride (TiB ₂ ) is an ideal protective material for cemented carbide micro-drills due to its excellent physical and chemical properties such as good electrical conductivity, high hardness and wear resistance. Titanium diboride is the most stable compound formed by boron and titanium elements, and has excellent properties such as corrosion resistance, oxidation resistance, and good electrical conductivity. Moreover, TiB ₂ has a high melting point, and its hardness is second only to superhard materials such as diamond and cubic boron nitride. As a hard wear-resistant film, it has broad application prospects in places where wear-resistant is required such as machining and high-temperature molding of equipment, and it also has certain application potential in the field of corrosion resistance. The layered structure of B atoms similar to graphite and the electrons in the outer layer of Ti determine that TiB has good electrical conductivity and metallic luster, and the Ti _- B bond between the B atomic plane and the Ti atomic plane makes the _TiB2 material have high hardness and The characteristic of brittleness. Although studies _on the structure and properties of TiB2 thin films have been carried out for decades, few commercial studies have been carried out so far due to the difficulty of producing high-quality films with good mechanical properties suitable for industrial applications. Therefore, it is very necessary to improve the toughness and tool bonding force of the films without significantly sacrificing the hardness of _TiB films.

Magnetron sputtering is a low-temperature, low-damage, high-speed deposition sputtering technology. It has outstanding advantages such as uniformity, compactness, small pinholes, high purity, strong adhesion, and wider application of targets. It is a kind of very commercial value and application prospect. Thin film deposition technology. The principle is to form an orthogonal electromagnetic field above the surface of the cathode target (that is, using the principle of magneto-control, the magnetic field is orthogonal to the electric field, and the direction of the magnetic field is parallel to the cathode surface). When the secondary electrons generated by sputtering are accelerated into high-energy electrons in the cathode drop zone, they cannot fly directly to the anode, but oscillate back and forth under the action of the orthogonal magnetic field, similar to cycloid motion, and continuously interact with gas molecules. The collision occurs, transferring energy to the gas molecules, ionizing them, becoming low-energy ions themselves, and finally drifting along the magnetic field lines to the auxiliary anode substrate near the cathode. In numerous studies, a common method is to prepare various ceramic/metal nanocomposite films by introducing modified metals into ceramic films. For example, Wang et al. (Toughening magnetronsputtered TiB ₂ coatings by Ni addition) added metallic Ni to the TiB ₂ hard film to achieve toughening effect. Also Ding et al. (Effect of Cu addition on the microstructure and properties of TiB ₂ films deposited by a hybrid system combining high power impulsemagnetron sputtering and pulsed dc magnetron sputtering) synthesized TiB ₂ -Cu films by doping amorphous Cu films The solid solution strengthening and nanocomposite structure are formed in the atomic TiB ₂ structure, which improves the toughness of the film. However, the method of introducing other metals by co-sputtering not only complicates the process, but also increases the requirements for equipment. The most important thing is that the addition of excess soft toughening metal will reduce the hardness of TiB ₂ film. Another approach is to prepare modified films with alternating structures, for example, TiB ₂ /aC nanomultilayers prepared by He et al. (Improving the mechanical and tribological properties of TiB ₂ /aC nanomultilayers by structural optimization) and Wang et al. (Structure and mechanical properties of Fe1-xMnx/TiB ₂ multilayer coatings: Possible role of transformation toughening), the TiB ₂ /Fe _1-x Mn _x series multilayer structure films can be effectively improved by adjusting the number of structural periods and changing the composition ratio of the film. toughness. However, the multilayer film with alternating structure can inevitably sacrifice its excellent properties such as hardness and wear resistance while improving the toughness of TiB ₂ film. In the above-mentioned studies, it is often chosen to achieve the purpose of modification by introducing other substances. However, the intervention of other substances often affects the preferred orientation of the (001) crystal orientation of TiB ₂ films, which inevitably reduces the outstanding mechanical properties such as inherent hardness. Therefore, it is urgent to prepare TiB ₂ coatings with high wear resistance, high hardness and strong binding force without changing the original structural system of TiB ₂ .

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a preparation method of TiB ₂ /Ti composite coating to solve the problems existing in the prior art.

For achieving the above object, the present invention provides the following scheme:

One of the technical solutions of the present invention: a preparation method of TiB ₂ /Ti composite coating, comprising the following steps:

(1) Pretreatment of base material: After polishing the base material, wash it with acetone and absolute ethanol in turn to obtain a pretreated base material;

(2) Pre-sputtering: the base material and the target are pre-sputtered; the target is a hot-pressed sintered TiB ₂ ceramic target with a purity of 99.9%;

(3) Deposition of Ti transition layer: the method of DC magnetron sputtering is used to deposit a Ti transition layer on the base material to obtain a base material with a Ti transition layer;

(4) Deposition of TiB ₂ hard protective layer: adopt the method of DC pulse magnetron sputtering to deposit a target material on the base material with Ti transition layer to obtain a TiB ₂ hard protective layer, which is the TiB ₂ /Ti composite coating.

Further, the base material is selected from any one of cemented carbide, silicon and metal.

Further, the metal is copper metal or titanium metal.

Further, the polishing specifically includes: grinding the base material with 200-mesh, 600-mesh, 1,000-mesh, and 2,000-mesh sandpaper in sequence.

Further, the cleaning is ultrasonic cleaning, and the cleaning time is 30min.

The surface quality of the base material directly affects the quality of the coating after deposition, and pretreatment of the base material can reduce the influence of the surface quality of the base material on the coating performance.

Further, the power of the pre-sputtering treatment is 300W, the bias voltage of the substrate is -300V, and the working time is 30min.

Further, before the pre-sputtering treatment, it also includes heating the sample base of the magnetron sputtering equipment to 350°C.

The pre-sputtering treatment can clean the surface of the target and the substrate, remove the residual gas, particles and other pollutants on the surface of the substrate, and enhance the bonding force of the coating.

Further, the power of the DC magnetron sputtering is 300W, the bias voltage of the substrate is -100V, and the working time is 30min.

Further, the deposition temperature of the DC pulse magnetron sputtering chamber is 350° C., the working pressure is 0.8 Pa, and the substrate bias voltage is 0-200V.

The second technical solution of the present invention: a TiB ₂ /Ti composite coating prepared by the above-mentioned preparation method.

The third technical solution of the present invention is the application of the above-mentioned TiB ₂ /Ti composite coating in the preparation of cemented carbide micro-drills.

The present invention discloses the following technical effects:

(1) Using the preparation method of the present invention, the TiB ₂ /Ti composite coating (protective layer) can be prepared on the surface of the cemented carbide micro-drill, and the preparation method of the present invention has high efficiency, strong universality, and good industrial The application prospect lays a technical foundation for the wide application of TiB ₂ hard coating.

(2) In the present invention, the structure and properties of TiB ₂ coating growth are changed by adjusting the substrate bias. The growth based on the coating always follows the principle of the lowest total free energy. By increasing the substrate bias during the deposition process, the ionized particles can be accelerated to bombard the surface under the action of the electric field, which promotes the diffusion of the particles on the coating surface. With the increase of the adjusted substrate bias, the coating gradually transformed into (001) crystal plane preferentially oriented growth, and the microstructure, hardness, toughness and wear resistance of the coating changed accordingly.

(3) The present invention realizes the preparation of a protective coating with high hardness and wear resistance on the surface of the cemented carbide, and the preparation method is simple and convenient for large-scale production.

(4) The present invention can control the thickness of the TiB ₂ coating by adjusting the deposition time, and can be used in different places and different application requirements.

(5) The coating prepared by the present invention shows that the coating is flat and dense in structure, and there is no impurity problem deposited under vacuum conditions. Compared with other technologies, the coating has a higher degree of density and a lower porosity.

(6) The TiB ₂ coating prepared by the present invention not only has extremely high hardness and wear resistance, but also has excellent corrosion resistance and electrical conductivity.

(7) The TiB ₂ /Ti composite coating prepared by the present invention further improves the bonding force between the coating and the substrate on the basis of maintaining the coating with high hardness and high wear resistance.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings required in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some of the present invention. In the embodiments, for those of ordinary skill in the art, other drawings can also be obtained according to these drawings without any creative effort.

Fig. 1 is the schematic diagram of the sputtering control equipment adopted in the present invention;

2 is a schematic structural diagram of the coatings prepared in Examples 1 to 5 and Example 6 of the present invention;

Fig. ₃ XRD diffractograms of TiB coatings prepared in Examples 1 to 5 of the present invention, wherein PMS-1 is Example 1, PMS-2 Example 2, PMS-3 Example 3, and PMS-4 Example 4 , PMS-5 embodiment 5;

4 is a scanning electron microscope photograph of the TiB coating prepared in Examples ₁ to 5 of the present invention, wherein (a) is Example 1, (b) is Example 2, (c) is Example 3, and (d) ) is embodiment 4, (e) is embodiment 5;

Fig. ₅ is the TiB coating surface element scanning distribution diagram (EDS) prepared in Example 3 of the present invention;

6 is a graph showing the mechanical test results of the TiB coatings prepared in Examples ₁ to 5 of the present invention, wherein (a) is the hardness, (b) is the elastic modulus, and (c) is the loading-unloading curve analysis of Example 5 , (d) is the loading-unloading curve of examples 1-5;

Fig. 7 is the H/E and H ³ /E ² ratio statistics diagram of the TiB ₂ coatings prepared in Examples 1-5 of the present invention;

8 is a graph showing the results of tribological testing of TiB coatings prepared in Examples ₁ to 5 of the present invention, wherein (a) is the coefficient of friction, and (b) is the wear rate;

9 is a scratch test chart of the coatings prepared in Example 3 and Example 6 of the present invention, wherein (a) is Example 6, and (b) is Example 3;

Figure 10 is a graph showing the mechanical test results of the coatings prepared in Examples 3 and 6 of the present invention, wherein (a) is hardness, (b) is elastic modulus, (c) is loading-unloading curve, and (d) is H/ E and H ³ /E ² ratio;

11 is a microscopic view of the TiB coating prepared in Example ₆ of the present invention;

Figure 12 is a photo of the material used in Example 3 of the present invention and the obtained material with coating, wherein (a) is a cemented carbide block, (b ₎ is the front side of the cemented carbide block with TiB coating, ( c) is the back side of the cemented carbide block with TiB coating _;

FIG. 13 is an electric polarization curve diagram of the coatings prepared in Examples 1 to 5 of the present invention.

Detailed ways

Various exemplary embodiments of the present invention will now be described in detail, which detailed description should not be construed as a limitation of the invention, but rather as a more detailed description of certain aspects, features, and embodiments of the invention.

It should be understood that the terms described in the present invention are only used to describe particular embodiments, and are not used to limit the present invention. Additionally, for numerical ranges in the present disclosure, it should be understood that each intervening value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intervening value in a stated range and any other stated value or intervening value in that stated range is also encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included or excluded in the range.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention relates. Although only the preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference for the purpose of disclosing and describing the methods and materials in connection with which the documents are referred. In the event of conflict with any incorporated document, the content of this specification controls.

It will be apparent to those skilled in the art that various modifications and variations can be made in the specific embodiments of the present invention without departing from the scope or spirit of the invention. Other embodiments will be apparent to those skilled in the art from the description of the present invention. The description and examples of the present application are only exemplary.

As used herein, "comprising," "including," "having," "containing," and the like, are open-ended terms, meaning including but not limited to.

Example 1

_A preparation method of TiB coating:

(1) Pretreatment of the base material: Select a WC cemented carbide block with a size of 20mm×20mm×2mm as the base material, and then use 200-mesh, 600-mesh, 1000-mesh, and 2000-mesh sandpaper in sequence. After grinding, place the base material on the It was ultrasonically cleaned in acetone for 30 min, then placed in anhydrous ethanol for ultrasonic cleaning for 30 min, dried with nitrogen, and then clamped and placed at the cavity sample base of the magnetron sputtering equipment.

(2) Base heating: Close the vacuum chamber, use the vacuum system to evacuate the pressure to 5×10 ^-3 Pa, then turn on the heating resistance wire, and heat the sample base for 3 hours until the temperature reaches 350°C.

(3) Pre-sputtering: Pour argon gas into the vacuum chamber, keep the working pressure of 0.8Pa, close the baffle, adopt the method of DC magnetron sputtering, under the condition of power of 300W and substrate bias of -300V Next, the base material and the target material (the target material is a hot-pressed sintered TiB ₂ ceramic target with a purity of 99.9%) are subjected to a pre-sputtering treatment for 30 minutes.

(4) Deposition of TiB ₂ hard protective layer: open the baffle, set the distance between the target and the base material (target-base distance) to 10cm, and then adopt the method of DC pulse magnetron sputtering, with a Ti transition layer Deposition the target material on the base material to obtain the TiB ₂ hard protective layer, turn off the sputtering power supply, then turn off the heating device, wait for the temperature to drop to 100 ° C, turn off the molecular pump, mechanical pump, cooling water in turn, after standing for more than 6h, turn on The samples were taken out of the vacuum chamber, and the material with the TiB ₂ /Ti composite coating was obtained.

The deposition temperature of the DC pulse magnetron sputtering chamber is 350°C, the working pressure is 0.8Pa, the substrate bias is 0V, the power supply is 300W, the duty cycle is 50%, and argon gas is introduced, and the rotation speed of the sample base is is 30rmp, the working time is 3h, and the deposition rate is 20nm/min.

Its X-ray diffraction (XRD) is shown in Figure 3 (PMS-1), and there is no sharp Bragg peak corresponding to the crystal on the XRD diffraction pattern. Fig. 4 is a scanning electron microscope picture. At this time, the cross-section of the coating grows disorderly and the surface morphology is loose. Its mechanical properties are shown in Figure 6, and the hardness is only 23.5GPa at this time. The H/E and H ³ /E ² ratios are only 0.11 and 0.27 GPa. And the wear rate shown in Fig. 8 is as high as 5.94×10 ^-10 m ³ /N·m.

The thickness of the TiB ₂ layer in the prepared TiB ₂ coating is about 3 μm.

Example 2

Same as Embodiment 1, the difference is that the bias voltage of the substrate in step (4) is 50V.

Its X-ray diffraction (XRD) is shown in Figure 3 (PMS-2), and there is no sharp Bragg peak corresponding to the crystal on the XRD diffraction pattern. Fig. 4 is a scanning electron microscope picture. At this time, the cross-section of the coating grows disorderly and the surface morphology is loose. Its mechanical properties are shown in Figure 6, and the hardness is 40.8GPa at this time. The H/E and H ³ /E ² ratios were 0.15 and 0.99 GPa. And the wear rate shown in FIG. 8 was 1.55×10 ⁻¹⁰ m ³ /N·m.

The thickness of the TiB ₂ layer in the prepared TiB ₂ coating is about 3 μm.

Example 3

Same as Embodiment 1, the difference is that the bias voltage of the substrate in step (4) is 100V.

Its X-ray diffraction (XRD) is shown in Figure 3 (PMS-3), and there is no sharp Bragg peak corresponding to the crystal on the XRD diffraction pattern. Fig. 4 is a scanning electron microscope picture. At this time, the cross-section of the coating grows disorderly and the surface morphology is loose. Its mechanical properties are shown in Figure 6, and the hardness is 43.3GPa at this time. The H/E and H ³ /E ² ratios were 0.17 and 1.28 GPa. And the wear rate shown in Figure 8 is 1.53×10 ^-11 m ³ /N·m, and the result of the scratch test bonding force shows that the critical loads are LC1: 8.631N, LC2: 12.577N, and LC3: 18.667N.

The thickness of the TiB ₂ layer in the prepared TiB ₂ coating is about 3 μm.

Example 4

Same as Embodiment 3, the difference is that the bias voltage of the substrate in step (4) is 150V.

Its X-ray diffraction (XRD) is shown in Figure 3 (PMS-4), and there is no sharp Bragg peak corresponding to the crystal on the XRD diffraction pattern. Fig. 4 is a scanning electron microscope picture. At this time, the cross-section of the coating grows disorderly and the surface morphology is loose. Its mechanical properties are shown in Figure 6, and the hardness is 46.0GPa at this time. The H/E and H ³ /E ² ratios were 0.16 and 1.32 GPa. And the wear rate shown in FIG. 8 was 2.57×10 ⁻¹¹ m ³ /N·m.

The thickness of the TiB ₂ layer in the prepared TiB ₂ coating is about 3 μm.

Example 5

Same as Embodiment 3, the difference is that the bias voltage of the substrate in step (4) is 200V.

Its X-ray diffraction (XRD) is shown in Figure 3 (PMS-5), and there is no sharp Bragg peak corresponding to the crystal on the XRD diffraction pattern. Fig. 4 is a scanning electron microscope picture. At this time, the cross-section of the coating grows disorderly and the surface morphology is loose. Its mechanical properties are shown in Figure 6, and the hardness is 30.0GPa at this time. The H/E and H ³ /E ² ratios were 0.10 and 0.32 GPa. And the wear rate shown in FIG. 8 was 2.64×10 ⁻¹¹ m ³ /N·m.

The thickness of the TiB ₂ layer in the prepared TiB ₂ coating is about 3 μm.

Example 6

A preparation method of TiB ₂ /Ti composite coating:

(1) Pretreatment of the base material: Select a WC cemented carbide block with a size of 20mm×20mm×2mm as the base material, and then use 200-mesh, 600-mesh, 1000-mesh, and 2000-mesh sandpaper in sequence. After grinding, place the base material on the It was ultrasonically cleaned in acetone for 30 min, then placed in anhydrous ethanol for ultrasonic cleaning for 30 min, dried with nitrogen, and then clamped and placed at the cavity sample base of the magnetron sputtering equipment.

(2) Base heating: Close the vacuum chamber, use the vacuum system to evacuate the pressure to 5×10 ^-3 Pa, then turn on the heating resistance wire, and heat the sample base for 3 hours until the temperature reaches 350°C.

(3) Pre-sputtering: Pour argon gas into the vacuum chamber, keep the working pressure of 0.8Pa, close the baffle, adopt the method of DC magnetron sputtering, under the condition of power of 300W and substrate bias of -300V Next, the base material and the target material (the target material is a hot-pressed sintered TiB ₂ ceramic target with a purity of 99.9%) are subjected to a pre-sputtering treatment for 30 minutes.

(4) Deposition of Ti transition layer: The distance between the Ti metal element (purity of 99%) and the base material is set to 10 cm, and then the Ti transition layer is deposited on the base material by DC magnetron sputtering to obtain a Ti transition layer. Base material for transition layers.

The deposition temperature of the DC magnetron sputtering chamber is 350°C, the working pressure is 0.8Pa, the power supply is 300W, the substrate bias voltage is -100V, argon gas is introduced, the rotation speed of the sample base is 30rmp, and the working time is 30min. .

(5) Deposition of TiB ₂ hard protective layer: open the baffle, set the distance between the target and the base material (target-base distance) to 10cm, and then adopt the method of DC pulse magnetron sputtering, with a Ti transition layer Deposition the target material on the base material to obtain the TiB ₂ hard protective layer, turn off the sputtering power supply, then turn off the heating device, wait for the temperature to drop to 100 ° C, turn off the molecular pump, mechanical pump, cooling water in turn, after standing for more than 6h, turn on The samples were taken out of the vacuum chamber, and the material with the TiB ₂ /Ti composite coating was obtained.

The deposition temperature of the DC pulse magnetron sputtering chamber is 350°C, the working pressure is 0.8Pa, the substrate bias is 0V, the power supply is 300W, the duty cycle is 50%, and argon gas is introduced, and the rotation speed of the sample base is is 30rmp, the working time is 3h, and the deposition rate is 20nm/min.

Through the mechanical property test, the hardness of the sample of Example 6 is 40.21GPa. The H/E and H ³ /E ² ratios were 0.16 and 1.11 GPa. The wear rate was 1.28×10 ^-11 m ³ /N·m. The results of the scratch test binding force show that the critical load is LC1: 15.178N, LC2: 23.532N, and LC3: 27.476N.

The thickness of TiB ₂ layer in the prepared TiB ₂ /Ti composite coating is about 3 μm, and the thickness of Ti layer is about 0.5 μm.

Example 7

Same as Example 6, the difference is that the target-to-base distance in step (4) is 15 cm.

Example 8

Same as Example 6, the difference is that the target-to-base distance in step (4) is 5 cm.

Example 9

With Embodiment 6, the difference is that the working air pressure in step (4) is 5Pa.

Example 10

Same as Example 6, the difference is that the working air pressure in step (4) is 0.1Pa.

Example 11

Same as Embodiment 6, the difference is that the bias voltage of the substrate in step (4) is 300V.

Example 12

Same as Example 6, the difference is that the rotation speed of the sample base in step (4) is 30 rmp.

Comparative Example 1

Same as Example 6, the difference is that in step (3), the power of DC magnetron sputtering is 300W, the substrate bias voltage is -100V, and the working time is 10min.

Comparative Example 2

Same as Embodiment 6, the difference is that the working time in step (4) is 1h.

Effect example 1

The binding force values of the coatings prepared in Example 3 and Example 6 were determined, and the results are shown in Table 1.

Table 1

LC1 LC2 LC3 TiB₂ 8.631N 12.577N 18.667N TiB₂/Ti 15.178N 23.532N 27.476N

Fig. 1 is the schematic diagram of the sputtering control equipment adopted in the present invention;

2 is a schematic structural diagram of the coatings prepared in Examples 1 to 5 and Example 6 of the present invention;

Fig. ₃ XRD diffractograms of TiB coatings prepared in Examples 1 to 5 of the present invention, wherein PMS-1 is Example 1, PMS-2 Example 2, PMS-3 Example 3, and PMS-4 Example 4 , PMS-5 embodiment 5;

4 is a scanning electron microscope photograph of the TiB coating prepared in Examples ₁ to 5 of the present invention, wherein (a) is Example 1, (b) is Example 2, (c) is Example 3, and (d) ) is embodiment 4, (e) is embodiment 5;

Fig. ₅ is the TiB coating surface element scanning distribution diagram (EDS) prepared in Example 3 of the present invention;

6 is a graph showing the mechanical test results of TiB coatings prepared in Examples ₁ to 5 of the present invention, wherein (a) is the hardness, (b) is the elastic modulus, and (c) is the loading-unloading curve data of Example 5 Analysis, (d) is the loading-unloading curve of Examples 1-5;

Fig. 7 is the H/E and H ³ /E ² ratio statistics diagram of the TiB ₂ coatings prepared in Examples 1-5 of the present invention;

8 is a graph showing the results of tribological testing of TiB coatings prepared in Examples ₁ to 5 of the present invention, wherein (a) is the coefficient of friction, and (b) is the wear rate;

9 is a scratch test chart of the coatings prepared in Examples 3 and 6 of the present invention, wherein (a) is the scratch chart of Example 6, and (b) is the scratch chart of Example 3;

Figure 10 is a graph showing the mechanical test results of the coatings prepared in Examples 3 and 6 of the present invention, wherein (a) is hardness, (b) is elastic modulus, (c) is loading-unloading curve, and (d) is H/ The ratio of E and H ³ /E ² ;

11 is a structural diagram of the TiB coating prepared in Example ₆ of the present invention;

Figure 12 is a photograph of the material used in Example 3 of the present invention and the obtained material with coating, wherein (a) is a cemented carbide block, (b) is the front side of the cemented carbide block with TiB coating, (c _{) )} is the backside of the cemented carbide block with TiB coating.

FIG. 13 is an electric polarization curve diagram of the coatings prepared in Examples 1 to 5 of the present invention.

It can be seen from FIG. 13 that the coatings prepared in Examples 1 to 5 have tested corrosion currents of 21.7 μA·cm ⁻² to 1.159 μA·cm ⁻² in sodium chloride solution.

From the relevant performance tests and data analysis of the above examples, it can be seen that by increasing the substrate bias in the deposition process, the coating gradually transforms into (001) crystal plane preferentially oriented growth (0.149 for Example 1 and 0.751 for Example 5) , the microstructure, hardness and toughness (H ³ /E ² ratio) of the coating changed accordingly. This is because the growth of the coating always follows the principle of the lowest total free energy. By increasing the substrate bias in the deposition process, the ionized particles can be accelerated to bombard the surface under the action of the electric field, and the diffusion of the particles on the coating surface can be promoted. At the same time, the change of substrate bias has a great influence _on the wear resistance of TiB coating. The successfully prepared TiB ₂ /Ti transition layer structure not only has excellent mechanical properties and wear resistance, but also its bonding force with the substrate is greatly improved. And the conductivity of TiB ₂ /Ti composite coating was tested to be 5～7×10 ^-6 Ω·m. To sum up, the coating prepared by appropriate process parameters and using the transition layer structure can obtain excellent surface strength, improve its mechanical properties, wear resistance and film-base bonding force, and greatly expand the titanium diboride. Coating application scenarios.

The above-mentioned embodiments are only to describe the preferred mode of the present invention, but not to limit the scope of the present invention. Without departing from the design spirit of the present invention, those of ordinary skill in the art can Variations and improvements should fall within the protection scope determined by the claims of the present invention.

Claims (10)

1. a preparation method of TiB ₂ /Ti composite coating, is characterized in that, comprises the following steps: (1) Pretreatment of base material: After polishing the base material, wash it with acetone and absolute ethanol in turn to obtain a pretreated base material; (2) Pre-sputtering: the base material and the target are pre-sputtered; the target is a hot-pressed sintered TiB ₂ ceramic target with a purity of 99.9%; (3) Deposition of Ti transition layer: the method of DC magnetron sputtering is used to deposit a Ti transition layer on the base material to obtain a base material with a Ti transition layer; (4) Deposition of TiB ₂ hard protective layer: adopt the method of DC pulse magnetron sputtering to deposit a target material on the base material with Ti transition layer to obtain a TiB ₂ hard protective layer, which is the TiB ₂ /Ti composite coating. 2 . The preparation method of the TiB ₂ /Ti composite coating according to claim 1 , wherein the base material is selected from any one of cemented carbide, silicon and metal. 3 . 3 . The preparation method of the TiB ₂ /Ti composite coating according to claim 1 , wherein the polishing specifically comprises: grinding the base material with 200-mesh, 600-mesh, 1000-mesh, and 2000-mesh sandpaper in sequence. 4 . 4. The preparation method of TiB2/Ti composite coating according to claim ₁ , is characterized in that, described cleaning is ultrasonic cleaning, and cleaning time is 30min. 5 . The preparation method of the TiB ₂ /Ti composite coating according to claim 1 , wherein the power of the pre-sputtering treatment is 300W, the substrate bias voltage is -300V, and the working time is 30min. 6 . 6 . The preparation method of the TiB ₂ /Ti composite coating according to claim 1 , wherein before the pre-sputtering treatment, the method further comprises heating the sample base of the magnetron sputtering equipment to 350° C. 7 . 7 . The preparation method of the TiB ₂ /Ti composite coating according to claim 1 , wherein the power of the DC magnetron sputtering is 300W, the substrate bias is -100V, and the working time is 30min. 8 . 8 . The preparation method of the TiB ₂ /Ti composite coating according to claim 1 , wherein the deposition temperature of the DC pulsed magnetron sputtering chamber is 350° C., the working pressure is 0.8 Pa, and the substrate bias voltage is 0.8 Pa. 9 . 0 to 200V. 9. A TiB ₂ /Ti composite coating prepared by the preparation method according to any one of claims 1 to 8. 10. An application of the TiB ₂ /Ti composite coating of claim 9 in the preparation of cemented carbide micro-drills.

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