Diamond blade capable of machining high-quality cutting edge

Abstract

The invention belongs to the field of polycrystalline diamond compacts, and particularly relates to a diamond blade capable of machining a high-quality cutting edge. The preparation method of the diamond blade comprises the following steps: (1) uniformly mixing diamond micro-powder with the particle size of not more than 2 microns and vanadium carbide to obtain mixed powder; and (2) the mixed powder and a hard alloy substrate are assembled and then subjected to high-temperature and high-pressure sintering, gathering of diamond particles is hindered through vanadium carbide, the distribution uniformity of the diamond particles and adhesives among the diamond particles is improved, and the diamond blade capable of machining a high-quality cutting edge is obtained. According to the method, the small-particle-size diamond micro powder and the vanadium carbide are selected for mixing, the particle size of diamond particles is reduced, the distribution uniformity of an adhesive is improved, and therefore the number and the size of notches are reduced, and the size of the notches can reach 0.01 mm or below.

Description

Technical Field

[0001] The invention belongs to the field of polycrystalline diamond composite sheets, and in particular relates to a diamond blade capable of processing a high-quality cutting edge. Background Art

[0002] Polycrystalline diamond cutting tools not only have high hardness and wear resistance, but also have high thermal conductivity and low thermal expansion coefficient. Therefore, they are widely used in the cutting of non-ferrous metals and non-metallic materials. Currently, the cutting edge of polycrystalline diamond cutting tools is usually processed by grinding wheels, laser cutting or electro-spark erosion. After grinding, the cutting edge will produce varying degrees of micro-serrations (or notches), affecting the surface quality and processing accuracy of the workpiece. In particular, the cutting edge processed by electro-spark erosion has a large inward extension of the notch, which does not meet the corresponding cutting edge quality requirements.

[0003] The quality of cutting edge processing depends on external factors such as the device and method for cutting edge processing, as well as internal factors such as the structural design of the blade itself. In terms of external factors, the Chinese utility model patent with an authorization announcement date of September 5, 2023 and an authorization announcement number of CN219633297U discloses a PCD chamfering cutter edge grinding tool, which improves the cutting edge quality by using a grinding machine instead of a wire-cutting machine to process PCD chamfering cutters. The Chinese invention patent application with an application publication date of November 8, 2024 and an application publication number of CN118905745A provides a tool grinding method and tool that can effectively reduce the generation of micro-serrations on the cutting edge and improve the quality of the tool cutting edge.

[0004] However, in terms of internal factors, there are still few reports on how to reduce the number and size of notches after edge treatment and improve edge quality through the structural design of the diamond blade itself. Summary of the Invention

[0005] The purpose of the present invention is to provide a diamond blade capable of processing a high-quality cutting edge, so as to solve the problem that the diamond blade prepared by the prior art has a large notch size during cutting edge processing.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] A diamond blade capable of producing a high-quality cutting edge is produced by a method comprising the following steps:

[0008] (1) Diamond powder with a particle size of no more than 2 μm and vanadium carbide are mixed to obtain a mixed powder;

[0009] (2) Assembling the mixed powder and the cemented carbide substrate and then sintering at high temperature and high pressure, utilizing the vanadium carbide to hinder the aggregation of diamond particles, thereby improving the uniformity of the distribution of diamond particles and the adhesive between diamond particles, and obtaining a diamond blade that can be processed with a high-quality cutting edge.

[0010] This invention is a groundbreaking invention. Blade edge chips are primarily caused by the shedding of diamond particles or the loss of adhesive between diamond particles. Large diamond particles can create large chips, and adhesive agglomeration after edge treatment can also create large chips. Therefore, the present invention addresses these two issues by selecting a small-particle diamond powder and vanadium carbide mixture, reducing the diamond particle size and improving the uniformity of adhesive distribution, thereby reducing the number and size of chips to less than 0.01 mm.

[0011] Preferably, the mass of the vanadium carbide in step (1) is 0.5-2% of the mass of the diamond powder.

[0012] Preferably, the particle size of the vanadium carbide in step (1) is within 1 μm.

[0013] Preferably, the particle size of the vanadium carbide is 100 nm to 1 μm.

[0014] Preferably, the median particle size of the diamond powder in step (1) is 0.3 μm to 1.5 μm, and the maximum particle size does not exceed 2 μm. Further preferably, the median particle size of the diamond powder is 0.5 μm to 1.5 μm.

[0015] Preferably, the diamond blade obtained in step (2) is machined to produce a notch of no more than 0.01 mm. The machining of the cutting edge is preferably performed using an electrospark erosion method.

[0016] Preferably, the pressure of the high temperature and high pressure sintering in step (2) is 7.2±0.3 GPa and the temperature is 1330-1380°C. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a 1000x electron microscope photograph of the microstructure of the polycrystalline diamond flake obtained in Example 1 of the present invention;

[0018] Figure 2 This is a 1000x electron microscope photograph of the organizational structure of the polycrystalline diamond flake obtained in the comparative example;

[0019] Figure 3 This is a 2000x electron microscope photograph of the microstructure of the polycrystalline diamond flake obtained in Example 1 of the present invention;

[0020] Figure 4 This is a 2000x electron microscope photograph of the organizational structure of the polycrystalline diamond flake obtained in the comparative example;

[0021] Figure 5 This is a microscope photo of the edge of the polycrystalline diamond sheet obtained in Example 1 of the present invention after treatment;

[0022] Figure 6 This is a microscope photo of the polycrystalline diamond large piece obtained in the comparative example after edge treatment. DETAILED DESCRIPTION

[0023] (1) The preferred embodiment of the diamond blade capable of processing a high-quality cutting edge of the present invention is described as follows:

[0024] The diamond blade of the present invention, which can be processed to produce a high-quality cutting edge, mainly selects small-sized diamond particles and adds vanadium carbide powder (VC) during powder mixing to inhibit the aggregation of diamond particles, so that large pieces of particles will not fall off when the particles fall off; while the diamond particles are evenly distributed, the adhesive between the particles is also relatively evenly distributed, so that when the cutting edge is processed using electric sparks, no gaps larger than 0.01 mm will be generated after the cutting edge adhesive falls off, thereby improving the cutting edge quality.

[0025] The diamond blade generally comprises a cemented carbide substrate and a polycrystalline diamond layer. In the present invention, no additional adhesive is added when mixing the polycrystalline diamond layer. The adhesive in the layer comes from the infiltration of cobalt in the cemented carbide substrate.

[0026] Specifically, the steps for preparing the diamond blade capable of processing a high-quality cutting edge are as follows:

[0027] (1) Diamond powder with a particle size of no more than 2 μm and vanadium carbide are mixed to obtain a mixed powder;

[0028] This step utilizes physical mixing to achieve uniform mixing of diamond micropowder and vanadium carbide powder. Diamond micropowder with a median particle size of 0.3 to 1.5 μm and a maximum particle size of no more than 2 μm is used, combined with VC powder with a particle size of 100 nm to 1 μm (median particle size of 400 to 500 nm), and the amount of VC powder added is controlled to 0.5 to 2% of the mass of the diamond micropowder. This effectively achieves the invention's objectives and improves the uniformity of diamond particle and binder distribution during subsequent sintering to prepare diamond blades, reducing the presence of agglomerated diamond particles and binder, and achieving a uniformly distributed structure.

[0029] This step has no special requirements for mixing equipment. For example, a planetary ball mill or other mixing equipment can be used to achieve efficient mixing of the solid powder.

[0030] (2) Assembling the mixed powder and the cemented carbide substrate and then sintering at high temperature and high pressure, utilizing the vanadium carbide to hinder the aggregation of diamond particles, thereby improving the uniformity of the distribution of diamond particles and the adhesive between diamond particles, and obtaining a diamond blade that can be processed with a high-quality cutting edge.

[0031] Once the mixed powder is obtained, it can be assembled with a cemented carbide substrate and sintered at high temperature and high pressure according to relevant existing technologies. Subsequently, it undergoes electrospark treatment to reduce or minimize the generation of chipping after cutting edge treatment, improving cutting edge quality and, consequently, the quality of the workpiece.

[0032] The EDM process can be performed using existing techniques. High-temperature, high-pressure sintering can be performed at a pressure of 7.2 ± 0.3 GPa and a temperature of 1330-1380°C. The sintering process can be completed by maintaining the pressure at 7.2 ± 0.3 GPa and the temperature at 1330-1380°C for 200-300 seconds.

[0033] The notch size of conventional diamond blade cutting tools after processing is generally around 0.02mm, with some notches larger than 0.03mm present. A high-quality cutting edge is considered one with a notch size of 0.015mm or less, and no more than two notches larger than 0.01mm within a 10mm length of the cutting edge. The method of the present invention can produce a high-quality cutting edge with a notch size of no more than 0.01mm.

[0034] In addition, the present invention essentially redesigns the microstructure of the diamond blade and adopts other edge processing methods, such as grinding wheel grinding, laser cutting, etc. The diamond blade of the present invention is also expected to achieve higher edge quality.

[0035] The preferred embodiment is described below with examples. The VC powder used in the following examples has a median particle size of 500 nm and a maximum particle size of no more than 1 μm; the particle size range is between 100 nm and 1 μm.

[0036] Example 1

[0037] The diamond blade of the present embodiment can be processed to produce a high-quality cutting edge by the following steps:

[0038] (1) Diamond micropowder with a median particle size of 0.5 μm and a maximum particle size not exceeding 2 μm and VC powder with a median particle size of 500 nm are uniformly mixed on a planetary ball mill to obtain a mixed powder; wherein the mass of the VC powder is 1.5% of the mass of the diamond micropowder.

[0039] (2) After assembling the mixed powder and the cemented carbide substrate, a six-sided top press was used to maintain a pressure of 7.2 GPa and a temperature of 1350-1360°C for 200 seconds to obtain a large piece of polycrystalline diamond; the height of the cemented carbide substrate of the prepared diamond blade was 3.4 mm ± 0.1 mm, and the height of the polycrystalline diamond layer was 1 mm ± 0.1 mm.

[0040] Example 2

[0041] The diamond blade of the present embodiment can be processed to produce a high-quality cutting edge by the following steps:

[0042] (1) Diamond micropowder with a median particle size of 0.3 μm and a maximum particle size not exceeding 2 μm and VC powder with a median particle size of 500 nm are uniformly mixed on a planetary ball mill to obtain a mixed powder; wherein the mass of the VC powder is 0.5% of the mass of the diamond micropowder.

[0043] (2) After assembling the mixed powder and the cemented carbide substrate, a six-sided top press was used to maintain the pressure of 7.2 GPa and the temperature of 1330-1350°C for 200 s (compared with Example 1, the diamond powder has a finer particle size and a smaller proportion of VC, which is conducive to the diffusion of the adhesive and can be sintered at a lower temperature) to obtain large polycrystalline diamond sheets; the height of the cemented carbide substrate of the prepared diamond blade is 3.4±0.1 mm, and the height of the polycrystalline diamond layer is 1 mm±0.1 mm.

[0044] Example 3

[0045] The diamond blade of the present embodiment can be processed to produce a high-quality cutting edge by the following steps:

[0046] (1) Diamond micropowder with a median particle size of 1.5 μm and a maximum particle size not exceeding 2 μm and VC powder with a median particle size of 500 nm are uniformly mixed on a planetary ball mill to obtain a mixed powder; wherein the mass of the VC powder is 2% of the mass of the diamond micropowder.

[0047] (2) After assembling the mixed powder and the cemented carbide substrate, a six-sided top press was used to maintain the pressure of 7.2 GPa and the temperature of 1360-1380°C for 200 s (compared with Example 1, the diamond micropowder has a coarser particle size, the proportion of VC powder is larger, the adhesive diffusion channel is reduced, and sintering can be performed at a higher temperature) to obtain large polycrystalline diamond sheets; the height of the cemented carbide substrate of the prepared diamond blade is 3.4±0.1 mm, and the height of the polycrystalline diamond layer is 1 mm±0.1 mm.

[0048] (2) Comparative Example

[0049] The preparation method of the diamond blade of the comparative example is the same as that of Example 1, except that VC powder is not added during the mixing in step (1).

[0050] (3) Experimental examples

[0051] Experimental Example 1

[0052] The organizational structure of the polycrystalline diamond layer of the diamond blade obtained in Experimental Example 1 and Comparative Example was analyzed. The electron microscope photos of Example 1 at 1000 times and 2000 times were as follows: Figure 1 、 Figure 3 As shown, the 1000x and 2000x electron microscope photos of the comparative example are respectively as shown in FIG. Figure 2 、 Figure 4 shown.

[0053] Depend on Figures 1 to 4 It can be seen that compared with the comparative example, in the polycrystalline diamond layer of the diamond blade prepared in Example 1 after adding VC, the diamond particles are evenly distributed, and the adhesive is dispersed between the diamond particles without obvious large-sized agglomerations (greater than 2 μm) of the adhesive.

[0054] Experimental Example 2

[0055] The polycrystalline diamond sheets of Example 1 and the comparative example were processed by electric spark erosion. Specifically, the diamond blades in Example 1 were made into corresponding tools, and the tool edges were processed using a FANUC ROBOCUT electric spark wire cutting machine. The process was divided into three steps: roughing, semi-finishing, and finishing. The processing speeds were 3.0 mm / min, 4.0 mm / min, and 3.0 mm / min, respectively, and the path deviations were 0.135 mm, 0.115 mm, and 0.105 mm, respectively. Microscope photos of the cutting edges of Example 1 and the comparative example are shown in Figure 1. Figure 5 、 Figure 6 shown.

[0056] Depend on Figure 5 It can be seen that the number of notches produced by the cutting edge processing in Example 1 is small and the notch size is obviously below 0.01 mm, while Figure 6 The notch size after the cutting edge treatment is significantly larger than that in Example 1, indicating that this method can well improve the cutting edge quality, thereby improving the quality of the processed workpiece.

[0057] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A diamond blade capable of producing a high-quality cutting edge, characterized in that: The method is prepared by the following steps: (1) Diamond powder with a particle size of no more than 2 μm and vanadium carbide are mixed to obtain a mixed powder; (2) Assembling the mixed powder and the cemented carbide substrate and then sintering them at high temperature and high pressure, using the vanadium carbide to hinder the aggregation of diamond particles, improve the uniformity of the distribution of diamond particles and the adhesive between diamond particles, and obtain a diamond blade that can be processed with a high-quality cutting edge.

2. The diamond blade capable of machining a high-quality cutting edge according to claim 1, wherein: The mass of the vanadium carbide in step (1) is 0.5-2% of the mass of the diamond powder.

3. The diamond blade capable of machining a high-quality cutting edge according to claim 1 or 2, wherein: The particle size of the vanadium carbide in step (1) is within 1 μm.

4. The diamond blade capable of machining a high-quality cutting edge according to claim 3, wherein: The particle size of the vanadium carbide is 100 nm to 1 μm.

5. The diamond blade capable of machining a high-quality cutting edge according to claim 1, wherein: The median particle size of the diamond powder in step (1) is 0.3 μm to 1.5 μm, and the maximum particle size does not exceed 2 μm.

6. The diamond blade capable of machining a high-quality cutting edge according to claim 5, wherein: The median particle size of the diamond micropowder is 0.5 μm to 1.5 μm.

7. The diamond blade capable of machining a high-quality cutting edge according to claim 1, wherein: The diamond blade obtained in step (2) is machined to produce a cutting edge with a gap no greater than 0.01 mm.

8. The diamond blade capable of machining a high-quality cutting edge according to claim 1, wherein: The pressure of the high temperature and high pressure sintering in step (2) is 7.2±0.3GPa and the temperature is 1330-1380°C.

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