阅读说明：本技术 一种高附着力纳米刀具涂层及其制备方法 (High-adhesion nano cutter coating and preparation method thereof ) 是由 陈金海 梁文勇 刘涛 严晓倩 张�杰 于 2021-08-17 设计创作，主要内容包括：本申请涉及硬质涂层领域,具体公开了一种高附着力纳米刀具涂层及其制备方法。高附着力纳米刀具涂层包括从内向外依次包覆在经基体改性后刀具表面的CrN界面层、AlTiN中间层、AlTiN/TiSiN连接层和TiSiN包覆层,所述CrN界面层、AlTiN中间层、AlTiN/TiSiN连接层和TiSiN包覆层均采用沉积包覆的方案进行制备。其制备方法为：S1、取基体改性刀具并活化处理；S2、待刀具活化完成后,依次沉积,制备得所述高附着力纳米刀具涂层。另外,本申请优化了刀具材料的表面结构,提高了硬质涂层在刀具表面的附着性能和抗脱落性能。(The application relates to the field of hard coatings, and particularly discloses a high-adhesion nano cutter coating and a preparation method thereof. The high-adhesion nano tool coating comprises a CrN interface layer, an AlTiN intermediate layer, an AlTiN/TiSiN connecting layer and a TiSiN coating layer which are sequentially coated on the surface of the tool after the surface of the tool is modified by a matrix from inside to outside, wherein the CrN interface layer, the AlTiN intermediate layer, the AlTiN/TiSiN connecting layer and the TiSiN coating layer are all prepared by adopting a deposition coating scheme. The preparation method comprises the following steps: s1, taking a matrix modified cutter and activating; and S2, after the activation of the cutter is finished, sequentially depositing to prepare the high-adhesion nano cutter coating. In addition, the surface structure of the cutter material is optimized, and the adhesion performance and the anti-falling performance of the hard coating on the surface of the cutter are improved.)

1. The high-adhesion nano tool coating is characterized by comprising a CrN interface layer, an AlTiN intermediate layer, an AlTiN/TiSiN connecting layer and a TiSiN coating layer which are sequentially coated on the surface of a tool modified by a matrix from inside to outside, wherein the CrN interface layer, the AlTiN intermediate layer, the AlTiN/TiSiN connecting layer and the TiSiN coating layer are all prepared by adopting a deposition coating scheme.

2. The high-adhesion nanometer tool coating as claimed in claim 1, wherein the substrate modification comprises pre-sanding treatment and post-polishing treatment, and the substrate modification comprises:

(1) sanding pretreatment: taking a cutter material to be treated, cleaning, sanding, and adjusting the sanding granularity to be # 600;

(2) and (3) polishing post-treatment: and after polishing is finished, polishing the substrate, controlling the polishing pressure to be 10-20 KPa and the flow rate of polishing slurry to be 125mL/min, and finishing the modification of the substrate after polishing is finished.

3. The high-adhesion nanometer cutter coating as claimed in claim 2, wherein the sanding treatment is sanding treatment under a sanding pressure of 0.4MPa to 0.6MPa, a sanding distance of 100mm to 120mm, and a sanding angle of 25 ° to 35 °.

4. The high-adhesion nanometer cutter coating according to claim 2, wherein the sanding grains used in the sanding process comprise one or more of white corundum, brown corundum and zirconium corundum.

5. The high-adhesion nanometer tool coating according to claim 2, wherein the polishing slurry of step (2) comprises the following components in parts by weight:

50-60 parts of water;

10-15 parts of nano silica sol;

6-8 parts of alumina particles.

6. The high-adhesion nanometer tool coating according to claim 5, wherein the polishing slurry further comprises 3 to 5 parts by weight of a 1% sodium hydroxide solution by mass fraction.

7. The high-adhesion nanometer tool coating as claimed in claim 1, wherein the TiSiN coating layer comprises 6-8% of Si, 37-39% of Ti and 52-58% of N by atomic mass ratio.

8. The high-adhesion nanometer tool coating according to claim 1, wherein the thickness of the AlTiN/TiSiN connecting layer is 1-3 μm.

9. The preparation method of the high-adhesion nanometer cutter coating according to any one of claims 1 to 8, wherein the preparation steps of the high-adhesion nanometer cutter coating are as follows:

s1, placing the substrate modified cutter in a deposition vacuum chamber, heating and decompressing, and then activating the substrate modified cutter in a nitrogen atmosphere;

and S2, after the activation of the cutter is finished, sequentially depositing and coating a CrN interface layer, an AlTiN intermediate layer, an AlTiN/TiSiN connecting layer and a TiSiN coating layer on the surface of the cutter by taking Cr as a target material, AlTi as a target material, TiSi/AlTi as a target material and TiSi as a target material, and after the deposition is finished, preparing the high-adhesion nano cutter coating.

Technical Field

The application relates to the field of hard coatings, in particular to a high-adhesion nano cutter coating and a preparation method thereof.

Background

Generally, in a hard coating system, a coating layer is different from a substrate material, and during the deposition of the coating layer, the coating material is generally deposited on the surface of the substrate by means of chemical bonds, intermolecular forces, mechanical engagement, and the like. The layer-based material interaction is manifested as adhesion and the force or energy required to peel the layer-based apart is referred to as the bond force or bond strength. Because the layer-base interface between the coating and the substrate is a ligament connecting the coating and the substrate, the layer-base interface not only plays a role in transmitting external load borne by the coating, but also bears stress strain inside the coating. The quality of the layer-base interface bond has a large impact on the quality and lifetime of the coating.

The prior art can refer to Chinese invention patent with publication number CN102517539A, and discloses a method for improving the bonding strength of a hard coating (film) and a substrate interface, which is realized by processing a hard coating/substrate composite system at a low temperature of-50 ℃ to-273 ℃ or an ultralow temperature for 5-48 hours. The hard coating comprises nitride coatings such as TiN, CrN, TiAlN, TiSiN, CrAlTiN, BN and the like, C coatings such as diamond, diamond-like carbon and the like, and carbide coatings such as TiC, WC and the like. By applying the method, the bonding strength of the coating/substrate interface can be improved by 10-50%, and the deterioration of the substrate or the coating performance can be avoided when the traditional high-temperature annealing method is adopted; meanwhile, the low-temperature or ultralow-temperature treatment cost is low, and the applicable coating/matrix composite system is wide in variety.

In view of the above-mentioned related technologies, the applicant believes that the surface structure performance of the hard coating substrate of the existing cutting tool is poor, and it is difficult to form a continuous covering layer, which affects not only the mechanical properties of the coating but also the bonding strength of the coating, thereby reducing the anti-dropping performance of the nano cutting tool coating.

Disclosure of Invention

In order to overcome the defect of poor bonding strength between the conventional nano cutter coating and a substrate, the application provides a high-adhesion nano cutter coating and a preparation method thereof, and the following technical scheme is adopted:

in a first aspect, the application provides a high-adhesion nano tool coating, which comprises a CrN interface layer, an AlTiN intermediate layer, an AlTiN/TiSiN connecting layer and a TiSiN coating layer which are sequentially coated on the surface of a tool after the surface of the tool is modified by a matrix from inside to outside, wherein the CrN interface layer, the AlTiN intermediate layer, the AlTiN/TiSiN connecting layer and the TiSiN coating layer are prepared by adopting a deposition coating scheme.

Through adopting above-mentioned technical scheme, because this application has adopted multilayer stereoplasm coating sedimentary technical scheme in proper order, through the setting of multilayer cladding, on the one hand, can pass through multilayer cladding structure, satisfy the multiple needs that the stereoplasm coating set up, and simultaneously, multilayer structure's stereoplasm coating, for single layer construction's stereoplasm coating, can effectively improve stereoplasm coating structural strength, on this basis, this application has optimized the surface structure of cutter material, through carrying out modification treatment to its surface structure, can effectively get rid of dust granule to the substrate surface while, reduce its roughness, thereby improve the coating and collude even gomphosis effect of base member, promote the particle nucleation, improve rete quality and strengthen its bonding strength, thereby effectively improved the adhesion property and the anti falling performance of stereoplasm coating on the cutter surface.

Further, the matrix modification comprises sanding pretreatment and polishing post-treatment, and the matrix modification comprises the following steps: (1) sanding pretreatment: taking a cutter material to be treated, cleaning, sanding, and adjusting the sanding granularity to be # 600; (2) and (3) polishing post-treatment: and after polishing is finished, polishing the substrate, controlling the polishing pressure to be 10-20 KPa and the flow rate of polishing slurry to be 125mL/min, and finishing the modification of the substrate after polishing is finished.

By adopting the technical scheme, as the scheme of sanding pretreatment and polishing post-treatment is adopted in the application, the surface of the cutter is treated, wherein, the operation step of sanding pretreatment ensures that the surface of the workpiece obtains certain cleanliness by the impact and cutting action of the sand grain grinding material on the surface of the tool, improves the mechanical property of the surface of the workpiece, increases the adhesive force between the surface of the workpiece and the coating, improves the durability of the hard coating, on the basis, polishing treatment is carried out, although the roughness of the coating formed by sanding pretreatment is reduced, but the structure of the fine rough surface is irregular, the technical proposal of the application adopts polishing treatment to reduce the roughness of the surface structure, the surface structure of the cutter is mainly improved, so that the adhesion performance and the anti-falling performance of the hard coating on the surface of the cutter are effectively improved.

Furthermore, the sanding treatment is performed under the conditions that the sanding pressure is 0.4-0.6 MPa, the sanding distance is 100-120 mm, and the sanding angle is 25-35 degrees.

By adopting the technical scheme, because the pressure and the angle of sanding are optimized, the oxide layer and the impurities on the surface of the tool after sanding are effectively removed, the activity of the surface of the tool after sanding is further improved, and the compressive stress on the surface of the tool is improved, so that the adhesion performance and the anti-falling performance of the hard coating on the surface of the tool are effectively improved.

Furthermore, the sanding grains used in the sanding treatment comprise one or a mixture of more of white corundum, brown corundum and zirconium corundum.

By adopting the technical scheme, as the material of sanding is optimized, the different requirements of the cutter energy of different components are adjusted by selecting the material or the mixture of multiple materials, the purpose is finally to improve the roughness of the surface of the cutter through sanding, and the adhesion performance and the anti-falling performance of the hard coating on the surface of the cutter are further improved.

Further, the polishing slurry in the step (2) comprises the following substances in parts by weight: 50-60 parts of water, 10-15 parts of nano silica sol and 6-8 parts of alumina particles.

By adopting the technical scheme, the proportion of each component is adjusted while the composition of the polishing slurry is optimized, the silica sol is used as the polishing slurry of the dispersion medium, the polishing uniformity of the surface of the cutter in the polishing treatment process is improved, and meanwhile, the silica sol in the dispersion medium has good structural performance, so that the stability of the polishing slurry is improved, and the adhesion performance and the anti-falling performance of the hard coating on the surface of the cutter are further improved.

Further, the polishing slurry also comprises 3-5 parts by weight of a sodium hydroxide solution with the mass fraction of 1%.

By adopting the technical scheme, the composition of the polishing slurry is further limited, the pH value of the polishing slurry is changed by optimizing the composition of the polishing slurry, and the Zeta potential of alumina particles in the polishing slurry can be effectively improved by the pH value under an alkaline condition, so that the stability of the polishing slurry is improved, the polishing uniformity of the polishing slurry on the surface of a cutter in the polishing treatment process is improved in the actual use, and the adhesion performance and the anti-falling performance of a hard coating on the surface of the cutter are further improved.

Further, the TiSiN coating layer comprises 6-8% of Si, 37-39% of Ti and 52-58% of N in atomic mass ratio.

By adopting the technical scheme, because the Si element is added into the coating structure, the hardness and the high-temperature resistance of the coating material can be obviously improved by adding the Si element, and the high-temperature resistance and the strength of the cutter coating are improved in the actual use process.

Furthermore, the thickness of the AlTiN/TiSiN connecting layer is 1-3 mu m.

By adopting the technical scheme, the size of the cutter coating and the composition of raw materials are optimized, the AlTiN/TiSiN connecting layer is filled between the structures of the multilayer coatings to form good load and supporting effect, so that the coating can effectively prevent the bonding strength between the cutter surface and the coating under the action of external force, the structural performance of the whole coating is improved, and the adhesion performance and the anti-falling performance of the hard coating on the cutter surface are further improved.

In a second aspect, the present application provides a method for preparing a high-adhesion nano tool coating, wherein the preparation steps of the high-adhesion nano tool coating are as follows: s1, placing the substrate modified cutter in a deposition vacuum chamber, heating and decompressing, and then activating the substrate modified cutter in a nitrogen atmosphere; and S2, after the activation of the cutter is finished, sequentially depositing and coating a CrN interface layer, an AlTiN intermediate layer, an AlTiN/TiSiN connecting layer and a TiSiN coating layer on the surface of the cutter by taking Cr as a target material, AlTi as a target material, TiSi/AlTi as a target material and TiSi as a target material, and after the deposition is finished, preparing the high-adhesion nano cutter coating.

Through adopting above-mentioned technical scheme, because this application is through the modification treatment to cutter surface material, improved the bonding strength between cutter surface material and the coating on the one hand, improved cutter surface material's anti-shedding performance, on the other hand, this application adopts multilayer structure sedimentary scheme, effectively improves the component structure of coating, has optimized the ratio of coating to effectively reduce coating structure stress, thereby further improved the adhesion property and the anti-shedding performance of hard coating on the cutter surface.

In summary, the present application includes at least one of the following beneficial technical effects:

first, this application has adopted multilayer stereoplasm coating sedimentary technical scheme in proper order, setting through multilayer cladding, on the one hand, can pass through multilayer cladding's structure, satisfy the multiple needs that the stereoplasm coating set up, and simultaneously, multilayer structure's stereoplasm coating, for single layer construction's stereoplasm coating, can effectively improve stereoplasm coating structural strength, on this basis, this application has optimized the surface structure of cutter material, through carrying out modification treatment to its surface structure, can effectively get rid of dust granule to the substrate surface in, reduce its roughness, thereby improve colluding of coating and base body and link the gomphosis effect, promote the particle nucleation, improve its bonding strength of rete quality reinforcing, thereby effectively improved the adhesion property and the anti-performance that drops of stereoplasm coating on the cutter surface.

Secondly, the scheme of sanding pretreatment and polishing aftertreatment is adopted in the application, the surface of the tool is subjected to surface treatment, wherein the sanding pretreatment operation step enables the surface of the workpiece to obtain certain cleanliness through the impact and cutting action of a sand abrasive on the surface of the tool, the mechanical property of the surface of the workpiece is improved, the adhesion between the surface of the workpiece and a coating is increased, the durability of a hard coating is improved, and then polishing treatment is performed on the basis.

Thirdly, the proportion of each component is adjusted while the composition of the polishing slurry is optimized, the uniform polishing performance of the surface of the cutter in the polishing treatment process is improved by using the silica sol as the polishing slurry of the dispersion medium, and meanwhile, the stability of the polishing slurry is improved due to the good structural performance of the silica sol in the dispersion medium, so that the adhesion performance and the anti-falling performance of the hard coating on the surface of the cutter are further improved.

Drawings

FIG. 1 is an indentation pattern of a high adhesion nanodevice coating of a sample of example 1 of the present application;

FIG. 2 is an indentation pattern of a high adhesion nano-cutter coating of a sample of comparative example 1 of the present application;

FIG. 3 is an indentation pattern of a high adhesion nanodevice coating of the sample of comparative example 2 of the present application;

FIG. 4 is an indentation pattern of a high adhesion nanodevice coating of a sample of comparative example 3 of the present application;

FIG. 5 is an indentation pattern of a high adhesion nanodevice coating of a sample of comparative example 4 of the present application;

FIG. 6 is an indentation pattern of a high adhesion nanodutter coating of a sample of comparative example 1 of the present application.

Detailed Description

The present application will be described in further detail with reference to examples.

In the embodiment of the present application, the used apparatuses and raw materials and auxiliary materials are as follows, but not limited thereto:

a machine: HV-1000 type microhardness tester, high power scanning electron microscope, Zeiss's Smartzoom5 three-dimensional digital microscope.

Preparation example

Preparation example 1

5kg of water, 1kg of nano silica sol, 0.6kg of alumina particles and 0.3kg of sodium hydroxide solution with the mass fraction of 1% are respectively weighed, stirred and mixed to obtain the polishing solution 1.

Preparation example 2

5.5kg of water, 1.25kg of nano silica sol, 0.7kg of alumina particles and 0.4kg of sodium hydroxide solution with the mass fraction of 1% are respectively weighed and stirred to obtain the polishing solution 2.

Preparation example 3

6kg of water, 1.5kg of nano silica sol, 0.8kg of alumina particles and 0.5kg of sodium hydroxide solution with the mass fraction of 1% are respectively weighed and stirred to obtain the polishing solution 3.

Examples

Example 1

Sanding pretreatment: taking a cutter material to be treated, cleaning, and then sanding under the sanding pressure of 0.4MPaMPa, the sanding distance of 100mm and the sanding angle of 25 degrees, adjusting the sanding granularity to be #600, wherein the sanding material is white corundum;

and (3) polishing post-treatment: after polishing is finished, polishing the substrate, controlling the polishing pressure to be 10KPa and the flow rate of polishing slurry 1 to be 125mL/min, and finishing the modification of the substrate after polishing is finished;

activation treatment: placing the matrix modified cutter in a deposition vacuum chamber, heating and reducing pressure, and then activating the matrix modified cutter in a nitrogen atmosphere;

deposition and coating: after the activation of the cutter is finished, selecting a Cr target, an AlTi target, a TiSi/AlTi target and a TiSi target on the surface of the cutter in sequence, depositing and coating a CrN interface layer, an AlTiN intermediate layer, an AlTiN/TiSiN connecting layer and a TiSiN coating layer in sequence, adjusting the TiSiN coating layer to be 6% of Si, 37% of Ti and 52% of N according to the atomic mass ratio, controlling the thickness of the AlTiN/TiSiN connecting layer to be 1 mu m, and after the deposition is finished, preparing the high-adhesion nano cutter coating.

Example 2

Sanding pretreatment: taking a cutter material to be treated, cleaning, and then sanding under the sanding pressure of 0.5MPa, the sanding distance of 110mm and the sanding angle of 30 degrees, adjusting the sanding granularity to be #600, wherein the sanding material is white corundum;

and (3) polishing post-treatment: after polishing is finished, polishing the substrate, controlling the polishing pressure to be 15KPa and the flow rate of the polishing slurry 2 to be 125mL/min, and finishing the modification of the substrate after polishing is finished;

activation treatment: placing the matrix modified cutter in a deposition vacuum chamber, heating and reducing pressure, and then activating the matrix modified cutter in a nitrogen atmosphere;

deposition and coating: after the activation of the cutter is finished, selecting a Cr target, an AlTi target, a TiSi/AlTi target and a TiSi target on the surface of the cutter in sequence, depositing and coating a CrN interface layer, an AlTiN intermediate layer, an AlTiN/TiSiN connecting layer and a TiSiN coating layer in sequence, adjusting the TiSiN coating layer to be 7% of Si, 38% of Ti and 55% of N according to the atomic mass ratio, controlling the thickness of the AlTiN/TiSiN connecting layer to be 2 mu m, and after the deposition is finished, preparing the high-adhesion nano cutter coating.

Example 3

Sanding pretreatment: taking a cutter material to be treated, cleaning, and then sanding under the sanding pressure of 0.6MPa, the sanding distance of 120mm and the sanding angle of 35 degrees, adjusting the sanding granularity to be #600, wherein the sanding material is white corundum;

and (3) polishing post-treatment: after polishing is finished, polishing the substrate, controlling the polishing pressure to be 20KPa and the flow rate of polishing slurry 3 to be 125mL/min, and finishing the modification of the substrate after polishing is finished;

activation treatment: placing the matrix modified cutter in a deposition vacuum chamber, heating and reducing pressure, and then activating the matrix modified cutter in a nitrogen atmosphere;

deposition and coating: after the activation of the cutter is finished, selecting a Cr target, an AlTi target, a TiSi/AlTi target and a TiSi target on the surface of the cutter in sequence, depositing and coating a CrN interface layer, an AlTiN intermediate layer, an AlTiN/TiSiN connecting layer and a TiSiN coating layer in sequence, adjusting the TiSiN coating layer to be 8% of Si, 39% of Ti and 58% of N according to the atomic mass ratio, controlling the thickness of the AlTiN/TiSiN connecting layer to be 3 mu m, and after the deposition is finished, preparing the high-adhesion nano cutter coating.

Comparative example

Comparative example 1: the high-adhesion nano tool coating is different from the coating in the example 1 in that the surface of the tool is not modified in the comparative example 1, and the rest preparation conditions and the component proportion are the same as those in the example 1.

Comparative example 2: the difference between the high-adhesion nano tool coating and the embodiment 1 is that the modification scheme of sanding pretreatment is only adopted when the surface of the tool is modified in the comparative example 2, and the rest preparation conditions and the component proportion are the same as those in the embodiment 1.

Comparative example 3: the difference between the high-adhesion nano tool coating and the embodiment 1 is that the modification scheme of polishing post treatment is only adopted when the tool surface is modified in the comparative example 3, and the rest preparation conditions and the component proportion are the same as those in the embodiment 1.

Comparative example 4: the difference between the high-adhesion nanometer cutter coating and the embodiment 1 is that the polishing slurry in the comparative example 4 directly adopts nanometer alumina particles with equal mass, and the rest preparation conditions and the component proportion are the same as those in the embodiment 1.

Comparative example 5: the difference between the high-adhesion nanometer cutter coating and the embodiment 1 is that the polishing slurry in the comparative example 5 directly adopts silica sol with equal mass, and the rest preparation conditions and the component proportion are the same as those in the embodiment 1.

Comparative examples

Comparative example 1

Comparative example 1: a high-adhesion nanometer tool coating is different from the coating in the embodiment 1 in that no sodium hydroxide solution is added into the polishing slurry in the comparative embodiment 1, and the rest preparation conditions and the component proportion are the same as those in the embodiment 1.

Performance test

The performance tests of examples 1 to 3, comparative examples 1 to 5 and comparative example 1 were performed, and the indentation morphology and coating film-base binding force of the coatings were measured.

Detection method/test method

(1) Coating film-based bonding force: measuring the bonding strength of the coating and the matrix by using an MFT-4000 multifunctional material surface property tester, wherein the scratching speed is 6mm/min, the loading speed is 300N/min, the terminating load is 150N, measuring each group of samples for 3 times and averaging;

(2) and (3) indentation morphology of the coating: loading on the coating and the surface of the coating by adopting a Rockwell hardness tester, and observing an indentation formed after loading (as shown in figures 1-6);

(3) microhardness of coating: an HVS-1000 Vickers hardness tester is selected to detect the hardness of a matrix, the loading force is 5kgf, the loading time is 10s, each group of samples is measured for 5 times and averaged, a NanoTest (TM) Vantage nano mechanical testing system is adopted to measure the hardness of the coating, in order to avoid the influence of the hardness of the matrix on the hardness of the coating, the pressing depth is controlled within 10 percent of the thickness of the coating, the maximum pressing depth is 150nm, the pressing load is 10mN, the loading and unloading speed is 0.25mN/s, the pressure maintaining time is 10s, each group of samples is measured for 8 times and averaged; the specific detection results are shown in the following table 1 and fig. 1 to 6:

TABLE 1 Performance test Table

Referring to Table 1 and the comparison of the performance tests of FIGS. 1-6, it can be found that:

(1) the performance comparison is carried out by referring to table 1 and fig. 1 in combination with examples 1-3, and it can be seen from table 1 and fig. 1 that the coating prepared by the examples of the present application has good microhardness and the bonding strength of the coating and the base layer is excellent, which illustrates that the technical scheme of the present application adopts the technical scheme of sequentially depositing multiple hard coating layers, and can effectively improve the structural strength of the hard coating.

(2) Referring to table 1 and fig. 2 to 4, performance comparison is performed in combination with comparative examples 1 to 3, and as can be seen from table 1 and fig. 2 to 4, the microhardness and the bonding strength of the coating prepared in the embodiment of the present application are significantly reduced, which reflects that the technical scheme of the present application adopts the schemes of sanding pretreatment and polishing post-treatment to perform surface treatment on the surface of the tool, so that the mechanical properties of the surface of the workpiece are improved, the adhesion between the surface of the workpiece and the coating is increased, the roughness of the surface structure is also reduced, and the surface structure of the tool is improved, so that the adhesion property and the anti-falling property of the hard coating on the surface of the tool are effectively improved.

(3) Referring to table 1 and fig. 5, performance comparison is performed in combination with comparative examples 4 to 5, and it can be seen from table 1 and fig. 5 that the microhardness and the bonding strength of the coating prepared in the embodiment of the present application are significantly reduced, which reflects that the technical scheme of the present application optimizes the composition of the polishing slurry, and adjusts the ratio of each component, and the silica sol is used as the polishing slurry of the dispersion medium, so that the polishing uniformity of the tool surface during the polishing process is improved, and meanwhile, since the silica sol in the dispersion medium also has good structural properties, the stability of the polishing slurry is improved, thereby further improving the adhesion property and the anti-shedding property of the hard coating on the tool surface.

(4) Referring to table 1 and fig. 6, performance comparison is performed by combining comparative example 1 and examples 1 to 3, and it can be seen from table 1 and fig. 6 that the microhardness and the bonding strength of the coating prepared in the examples of the present application are slightly reduced, which reflects that the technical scheme of the present application further limits the composition of the polishing slurry, and the pH value of the polishing slurry is changed by optimizing the composition of the polishing slurry, and since the pH value can effectively improve the Zeta potential of alumina particles in the polishing slurry under an alkaline condition, the stability of the polishing slurry is improved, and the polishing uniformity of the tool surface in the polishing process is improved in the actual use, so that the adhesion performance and the anti-falling performance of the hard coating on the tool surface are further improved.

The present embodiment is only for explaining the present application, and it is not limited to the present application, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present application.