Hard alloy for cutter and preparation method thereof
By performing silicon-rare earth co-permeation treatment on the surface of the cemented carbide matrix and using ammonium chloride activator, the problem of cobalt-based carbide affecting diamond coating in cobalt-based carbide is solved, the coating quality and adhesion are improved, and the tool service life is extended.
Patent Information
- Application Number
- CN202510695141.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-27
- Publication Date
- 2025-09-05
AI Technical Summary
When diamond coating is deposited on the surface of cobalt-based cemented carbide, cobalt elements promote the dissolution and diffusion of carbon, leading to the formation of non-diamond carbon phases, reducing the purity and quality of the coating, and affecting service life.
The surface of the cemented carbide matrix was treated with silicon-rare earth co-permeation, and a diamond coating was prepared by chemical vapor deposition method. The ammonium chloride activator was used to promote the reaction of silicon and rare earth elements with cobalt at high temperatures, forming a solid solution, and inhibiting the migration and overflow of cobalt.
It improves the quality and adhesion of the diamond coating, extends the service life of cemented carbide tools, and the preparation method is simple to operate and has good permeability.
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Figure CN120591722A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of cemented carbide materials, in particular to a cemented carbide for cutting tools and a preparation method thereof. Background Art
[0002] When depositing diamond coating on the surface of cobalt-based cemented carbide, the cobalt element promotes the dissolution and diffusion of carbon, which inhibits the nucleation of diamond during the chemical vapor deposition process. At the same time, it catalyzes the formation of non-diamond carbon phases (such as graphite), resulting in the inclusion of amorphous carbon phases such as graphite in the diamond coating, reducing the purity and quality of the coating, affecting the deposition effect of the diamond coating, and thus reducing the service life of the cemented carbide. Summary of the Invention
[0003] Purpose of the invention: In order to solve the above technical problems, the present invention provides a cemented carbide for cutting tools and a preparation method thereof.
[0004] The technical solutions adopted are as follows:
[0005] A cemented carbide for cutting tools, comprising a cemented carbide substrate and a diamond coating;
[0006] The surface of the cemented carbide substrate is treated with silicon-rare earth co-penetration.
[0007] Furthermore, the cemented carbide substrate is a cobalt-containing cemented carbide.
[0008] Furthermore, the cobalt-containing cemented carbide is a YG-type cemented carbide.
[0009] Furthermore, a liquid infiltrant consisting of a trisilylamine-based rare earth complex, an activator and an organic solvent is used to perform silicon-rare earth co-infiltration treatment on the surface of the cemented carbide substrate.
[0010] Furthermore, the activator is ammonium chloride.
[0011] Furthermore, the organic solvent is an alcohol solvent.
[0012] Furthermore, the mass ratio of the trisilamine-based rare earth complex, the activator and the organic solvent is 1-2:0.1-0.2:3-5.
[0013] Furthermore, the preparation method of the trisilamide rare earth complex is as follows:
[0014] Under the protection of inert gas, rare earth chloride and sodium hexamethyldisilazide are added to tetrahydrofuran, stirred for reaction and then filtered, the filtrate is collected and distilled under reduced pressure, the residue is dissolved with n-hexane and then crystallized at low temperature, and finally the solid is collected by filtration.
[0015] Furthermore, the rare earth chloride salt is any one or a combination of two or more of YCl3, LaCl3, SmCl3, YbCl3, NdCl3, and EuCl3.
[0016] The present invention also provides a method for preparing cemented carbide for cutting tools:
[0017] The surface of the cemented carbide substrate is ground, polished, cleaned and dried, and then a liquid penetrant is sprayed on the surface of the cemented carbide substrate and dried. The cemented carbide substrate is then heated to 1000-1100°C for silicon-rare earth co-penetration treatment, and finally a diamond coating is prepared using chemical vapor deposition.
[0018] It has the following beneficial effects:
[0019] The present invention provides a cemented carbide for cutting tools. Ammonium chloride in the activator decomposes at high temperatures to produce gaseous products, HCl and NH3, which further promote the activation of silicon and rare earth elements in a trisilamine-based rare earth complex at high temperatures. This promotes the reaction of silicon and rare earth elements with cobalt on the surface of the cemented carbide substrate to form a solid solution, thereby passivating it. This inhibits the migration and overflow of cobalt, reduces the adverse effects of cobalt on the adhesion of the diamond coating, and improves the quality of the diamond coating and its adhesion to the cemented carbide substrate. Compared to powder and paste methods for preparing metal infiltration layers, the present invention is easier to operate. Because the liquid infiltration agent can be evenly distributed on the surface of the cemented carbide substrate, the resulting infiltration layer is more uniform, which is more conducive to the uniform deposition of the diamond coating and can effectively extend the service life of cemented carbide tools. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 This is the indentation morphology of the cemented carbide prepared in Example 1;
[0021] Figure 2 This is the indentation morphology of the cemented carbide prepared in Example 2;
[0022] Figure 3 This is the indentation morphology of the cemented carbide prepared in Example 3;
[0023] Figure 4 This is the indentation morphology of the cemented carbide prepared in Comparative Example 1;
[0024] Figure 5 This is the indentation morphology of the cemented carbide prepared in Comparative Example 2. DETAILED DESCRIPTION
[0025] Unless otherwise specified, the following examples and comparative examples were conducted in parallel, using the same processing steps and parameters.
[0026] Example 1:
[0027] This embodiment provides a cemented carbide for cutting tools, which is composed of a YG-10 cemented carbide substrate and a diamond coating;
[0028] The preparation method of the above-mentioned cemented carbide for cutting tools is as follows:
[0029] Under argon protection, 24.5g of anhydrous lanthanum trichloride and 55.2g of sodium hexamethyldisilazide were added to 500ml of anhydrous tetrahydrofuran, and the mixture was stirred at room temperature for 24h, and then the generated sodium chloride was removed by filtration. The filtrate was collected and distilled under reduced pressure until the remaining filtrate volume was 100ml. 500ml of n-hexane was added to dissolve the residue and then crystallized in a cold trap at -5°C for 8h. The solid was collected by filtration to obtain a trisilamide rare earth complex (La[N(SiMe3)2]3);
[0030] A trisilamine-based rare earth complex, ammonium chloride and ethanol with a mass ratio of 1:0.1:3 were mixed and ultrasonically oscillated for 30 minutes to obtain a liquid penetrant. The surface of YG-10 cemented carbide was ground, polished, cleaned and dried as a substrate. The liquid penetrant was sprayed onto the surface of the cemented carbide substrate using a spray bottle and dried. The spraying-drying steps were repeated ten times. The cemented carbide substrate was heated to 1000°C for silicon-rare earth co-penetration treatment for 5 minutes. Finally, the cemented carbide substrate was placed in the chamber of the MPCVD device. The back vacuum was first evacuated to below 1Pa, and then H2 was introduced. After the cavity was heated to 1000°C, the silicon-rare earth co-penetration treatment was carried out. After the internal gas pressure stabilizes, turn on the microwave power, input 2 kW microwave power, excite the plasma, and then gradually increase the microwave power to 5 kW, introduce CH4 to increase the gas pressure to 10±0.1 kPa, the flow ratio of CH4 and H2 is 1:49, the total gas flow is 400 sccm, and start depositing the diamond coating. The deposition temperature is 850±10℃ and the deposition time is 120 min. After the deposition is completed, stop introducing H2 and CH4, and gradually reduce the microwave power until the plasma is annihilated. Turn off the vacuum pump, inflate the cavity, and take out the sample.
[0031] In this embodiment, the bonding performance of the diamond coating was evaluated using the Rockwell indentation method, and the bonding strength of the diamond coating was rated according to the German VDI3198-1992 standard. A Rockwell hardness tester was used to make a Rockwell indentation on the diamond coating. The diamond indenter used had a top angle of 120°±20′, an applied load of 1470N, and a loading time of 10s. The indentation was then observed under a microscope. Figure 1 , it can be seen that the indentation of the diamond coating is intact, there is no peeling around it, and the bonding strength grade is HF1.
[0032] Example 2:
[0033] This embodiment provides a cemented carbide for cutting tools, which is composed of a YG-10 cemented carbide substrate and a diamond coating;
[0034] The preparation method of the above-mentioned cemented carbide for cutting tools is as follows:
[0035] Under argon protection, 24.5g of anhydrous lanthanum trichloride and 55.2g of sodium hexamethyldisilazide were added to 500ml of anhydrous tetrahydrofuran, and the mixture was stirred at room temperature for 24h, and then the generated sodium chloride was removed by filtration. The filtrate was collected and distilled under reduced pressure until the remaining filtrate volume was 100ml. 500ml of n-hexane was added to dissolve the residue and then crystallized in a cold trap at -5°C for 8h. The solid was collected by filtration to obtain a trisilamide rare earth complex (La[N(SiMe3)2]3);
[0036] A trisilylamine-based rare earth complex, ammonium chloride and ethanol with a mass ratio of 2:0.2:5 were mixed and ultrasonically oscillated for 30 minutes to obtain a liquid penetrant. The surface of YG-10 cemented carbide was ground, polished, cleaned and dried as a substrate. The liquid penetrant was sprayed onto the surface of the cemented carbide substrate using a spray bottle and dried. The spraying-drying steps were repeated ten times. The cemented carbide substrate was heated to 1000°C for silicon-rare earth co-penetration treatment for 5 minutes. Finally, the cemented carbide substrate was placed in the chamber of the MPCVD device. The back vacuum was first evacuated to below 1Pa, and then H2 was introduced. After the cavity was heated to 1000°C, the silicon-rare earth co-penetration treatment was carried out. After the internal gas pressure stabilizes, turn on the microwave power, input 2 kW microwave power, excite the plasma, and then gradually increase the microwave power to 5 kW, introduce CH4 to increase the gas pressure to 10±0.1 kPa, the flow ratio of CH4 and H2 is 1:49, the total gas flow is 400 sccm, and start depositing the diamond coating. The deposition temperature is 850±10℃ and the deposition time is 120 min. After the deposition is completed, stop introducing H2 and CH4, and gradually reduce the microwave power until the plasma is annihilated. Turn off the vacuum pump, inflate the cavity, and take out the sample.
[0037] In this embodiment, the bonding performance of the diamond coating was evaluated using the Rockwell indentation method, and the bonding strength of the diamond coating was rated according to the German VDI3198-1992 standard. A Rockwell hardness tester was used to make a Rockwell indentation on the diamond coating. The diamond indenter used had a top angle of 120°±20′, an applied load of 1470N, and a loading time of 10s. The indentation was then observed under a microscope. Figure 2 , it can be seen that the indentation of the diamond coating is intact, there is no peeling around it, and the bonding strength grade is HF1.
[0038] Example 3:
[0039] This embodiment provides a cemented carbide for cutting tools, which is composed of a YG-10 cemented carbide substrate and a diamond coating;
[0040] The preparation method of the above-mentioned cemented carbide for cutting tools is as follows:
[0041] Under argon protection, 27.9 g of anhydrous ytterbium trichloride and 55.2 g of sodium hexamethyldisilazide were added to 500 ml of anhydrous tetrahydrofuran, and the mixture was stirred at room temperature for 24 h. After that, the generated sodium chloride was removed by filtration. The filtrate was collected and distilled under reduced pressure until the volume of the remaining filtrate was 100 ml. 500 ml of n-hexane was added to dissolve the residue, and then crystallized in a cold trap at -5 ° C for 8 h. The solid was collected by filtration to obtain a trisilamide rare earth complex (Yb[N(SiMe3)2]3);
[0042] A trisilamine-based rare earth complex, ammonium chloride and ethanol with a mass ratio of 1:0.1:3 were mixed and ultrasonically oscillated for 30 minutes to obtain a liquid penetrant. The surface of YG-10 cemented carbide was ground, polished, cleaned and dried as a substrate. The liquid penetrant was sprayed onto the surface of the cemented carbide substrate using a spray bottle and dried. The spraying-drying steps were repeated ten times. The cemented carbide substrate was heated to 1000°C for silicon-rare earth co-penetration treatment for 5 minutes. Finally, the cemented carbide substrate was placed in the chamber of the MPCVD device. The back vacuum was first evacuated to below 1Pa, and then H2 was introduced. After the cavity was heated to 1000°C, the silicon-rare earth co-penetration treatment was carried out. After the internal gas pressure stabilizes, turn on the microwave power, input 2 kW microwave power, excite the plasma, and then gradually increase the microwave power to 5 kW, introduce CH4 to increase the gas pressure to 10±0.1 kPa, the flow ratio of CH4 and H2 is 1:49, the total gas flow is 400 sccm, and start depositing the diamond coating. The deposition temperature is 850±10℃ and the deposition time is 120 min. After the deposition is completed, stop introducing H2 and CH4, and gradually reduce the microwave power until the plasma is annihilated. Turn off the vacuum pump, inflate the cavity, and take out the sample.
[0043] In this embodiment, the bonding performance of the diamond coating was evaluated using the Rockwell indentation method, and the bonding strength of the diamond coating was rated according to the German VDI3198-1992 standard. A Rockwell hardness tester was used to make a Rockwell indentation on the diamond coating. The diamond indenter used had a top angle of 120°±20′, an applied load of 1470N, and a loading time of 10s. The indentation was then observed under a microscope. Figure 3 , it can be seen that the indentation of the diamond coating is intact, there is no peeling around it, and the bonding strength grade is HF1.
[0044] Comparative Example 1:
[0045] The method is basically the same as Example 1, except that the diamond coating is directly deposited on the surface of the cemented carbide substrate.
[0046] This comparative example provides a cemented carbide for cutting tools, which is composed of a YG-10 cemented carbide substrate and a diamond coating;
[0047] The preparation method of the above-mentioned cemented carbide for cutting tools is as follows:
[0048] The surface of YG-10 cemented carbide was ground, polished, cleaned and dried as a substrate. The cemented carbide substrate was placed in the chamber of the MPCVD device. The back vacuum was first evacuated to below 1Pa, and then H2 was introduced. After the gas pressure in the cavity was stable, the microwave power was turned on, and a microwave power of 2 kW was input to excite the plasma. The microwave power was then gradually increased to 5 kW, and CH4 was introduced to increase the gas pressure to 10±0.1 kPa. The flow ratio of CH4 and H2 was 1:49, and the total gas flow rate was 400 sccm. The diamond coating was started to be deposited at a deposition temperature of 850±10℃ and a deposition time of 120 min. After the deposition was completed, the introduction of H2 and CH4 was stopped, and the microwave power was gradually reduced until the plasma was annihilated. The vacuum pump was turned off, the cavity was inflated, and the sample was taken out.
[0049] The bonding performance of the diamond coating in this comparative example was evaluated using the Rockwell indentation method, and the bonding strength of the diamond coating was rated according to the German VDI3198-1992 standard. A Rockwell hardness tester was used to make a Rockwell indentation on the diamond coating. The diamond indenter used had a top angle of 120°±20′, an applied load of 1470N, and a loading time of 10s. The indentation was then observed under a microscope. Figure 4 , it can be seen that there is a lot of peeling around the indentation of the diamond coating, and the bonding strength grade is HF5 or HF6.
[0050] Comparative Example 2:
[0051] The process is substantially the same as in Example 1, except that ammonium chloride is not added.
[0052] The bonding performance of the diamond coating in this comparative example was evaluated using the Rockwell indentation method, and the bonding strength of the diamond coating was rated according to the German VDI3198-1992 standard. A Rockwell hardness tester was used to make a Rockwell indentation on the diamond coating. The diamond indenter used had a top angle of 120°±20′, an applied load of 1470N, and a loading time of 10s. The indentation was then observed under a microscope. Figure 5 , it can be seen that there are a lot of peeling around the indentation of the diamond coating, and the bonding strength grade is HF3.
[0053] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.
Claims
1. A cemented carbide for cutting tools, characterized in that: It consists of a carbide substrate and a diamond coating; The surface of the cemented carbide substrate is treated with silicon-rare earth co-penetration.
2. The cemented carbide for cutting tools according to claim 1, wherein: The cemented carbide substrate is a cobalt-containing cemented carbide.
3. The cemented carbide for tool according to claim 2, wherein: The cobalt-containing cemented carbide is a YG-type cemented carbide.
4. The cemented carbide for cutting tools according to claim 1, wherein: The surface of the cemented carbide substrate is treated with silicon-rare earth co-penetration by using a liquid penetrant consisting of a trisilylamine rare earth complex, an activator and an organic solvent.
5. The cemented carbide for tool according to claim 4, wherein: The activator is ammonium chloride.
6. The cemented carbide for tool according to claim 4, wherein: The organic solvent is an alcohol solvent.
7. The cemented carbide for cutting tools according to claim 4, wherein: The mass ratio of the trisilamine-based rare earth complex, the activator and the organic solvent is 1-2:0.1-0.2:3-5.
8. The cemented carbide for cutting tools according to claim 1, wherein: The preparation method of the trisilylamine rare earth complex is as follows: Under the protection of inert gas, rare earth chloride and sodium hexamethyldisilazide are added to tetrahydrofuran, stirred for reaction and then filtered, the filtrate is collected and distilled under reduced pressure, the residue is dissolved with n-hexane and then crystallized at low temperature, and finally the solid is collected by filtration.
9. The cemented carbide for cutting tools according to claim 8, wherein: The rare earth chloride salt is any one of YCl3, LaCl3, SmCl3, YbCl3, NdCl3, and EuCl3, or a combination of two or more thereof.
10. A method for preparing a cemented carbide for a tool as claimed in claims 4 to 9, characterized in that: The surface of the cemented carbide substrate is ground, polished, cleaned and dried, and then a liquid penetrant is sprayed on the surface of the cemented carbide substrate and dried. The cemented carbide substrate is then heated to 1000-1100°C for silicon-rare earth co-penetration treatment, and finally a diamond coating is prepared using chemical vapor deposition.