Novel microwave sintering method for directionally arranged diamond tool

Abstract

The invention discloses a diamond particle directional arrangement method for a microwave sintering diamond tool based on a finite element simulation software COMSOL fitting temperature field. The diamond particle directional arrangement method is implemented according to the following steps: 1, manufacturing a diamond tool bit compact according to an optimal diamond directional arrangement mode; 2, putting the diamond tool bit compact into a ceramic crucible, and putting the ceramic crucible into microwave sintering equipment; and 3, performing microblog sintering on the diamond tool bit according to a set process. By the adoption of the method, the indirect heating effect of microwave heating diamond particles on the metal matrix can be fully utilized, and the microwave sintering diamond tool bit process is optimized by selecting the optimal directional arrangement method. According to the invention, the heating efficiency of the pressed blank is improved while the constant temperature in the diamond production process is ensured, so that the quality of a diamond tool is improved.

Description

Technical Field

[0001] This invention patent relates to the field of microwave sintering diamond tool technology, specifically to a novel microwave sintering method for oriented diamond tools. Background Technology

[0002] Diamond is a material with numerous superior properties, including extremely high hardness, high breakdown voltage, high thermal conductivity, and chemical stability. Benefiting from these properties, diamond tools offer advantages such as high wear resistance and are widely used in applications such as stone cutting, polishing, and oilfield drilling, encompassing various products including saw blades and grinding wheels. Given the increasing demands on material processing in the future, the demand for diamond tools is expected to continue to rise.

[0003] Currently, the mainstream production method for diamond tools is the traditional hot-press sintering method, where the green diamond tool blank is placed in a mold and sintered under high temperature and pressure. The main drawbacks of hot-press sintering are twofold: first, the necessity of a mold significantly limits the size and quantity of the sintered diamond tools; second, the reliance on traditional heating methods such as heat radiation, convection, and conduction results in significant energy waste. However, with technological advancements, microwave sintering of diamond tools has become possible. Microwave sintering uses pressureless sintering, eliminating the limitations of molds, and microwave heating is fundamentally superior to traditional heating methods, making it the mainstream method for future diamond tool production.

[0004] Currently, the production of diamond tools using microwave sintering faces challenges because microwaves are not easily able to heat metal blocks. Once the metal powder in the diamond tool green blank becomes dense, microwave sintering becomes difficult. To meet the demands of modern industrial production, reduce costs, and improve production stability, a key factor is ensuring continuous microwave heating of the diamond tool green blank. Therefore, this invention, based on practical production experience, proposes a novel microwave sintering method for directional diamond tools by improving the arrangement distance of diamond particles in the diamond tool green blank and relying on the indirect sintering effect of microwave sintering. Summary of the Invention

[0005] The technical problem to be solved by this invention is to provide a novel microwave sintering method for oriented diamond tools. The purpose is to address the issues of difficulty in heating metal blocks using microwave sintering, and the difficulty in continuing microwave sintering of diamond tools after the metal particles have densified, leading to a decrease in yield and productivity. By rationally designing the arrangement of diamond particles in the green blank, the metal matrix of the diamond tool is kept at the required sintering temperature. This invention, through a combination of simulation and actual production, reduces production costs and improves the product yield, making it suitable for large-scale production of microwave-sintered diamond tools.

[0006] A novel microwave sintering method for oriented diamond tools includes the following steps:

[0007] Step 1: Select the optimal diamond orientation arrangement, add metal powder and diamond particles to an automatic pressing device to make a diamond tool blank.

[0008] Step 2: Place the diamond tool blank into a ceramic crucible and then into a microwave sintering device.

[0009] Step 3: Microwave sinter the diamond compact. Heat the diamond compact to the target temperature, maintain it for the target time, then turn off the power. After cooling to a suitable temperature, remove the crucible to obtain the finished diamond tool.

[0010] As a preferred embodiment, the blank size of the cutter head in step 1 is 24×12×5mm, wherein the long side with a span of 24mm is composed of an arc with a diameter of 350mm.

[0011] As a preferred embodiment, the optimal diamond orientation arrangement in step 1 involves placing four layers of 80-mesh diamond particles within a metal matrix, with 13 rows per layer. Odd-numbered layers have 5 columns per layer, and even-numbered layers have 4 columns per layer, with adjacent layers alternating. The distance between diamond particles is 1.770 mm, the vertical distance between layers is 1.520 mm, and the distance from the edge of the metal matrix to the nearest diamond particle is 1.385 mm. The diamond particles in the odd-numbered layers are arranged symmetrically along the geometric axis of symmetry of their respective cross-sections.

[0012] As a preferred embodiment, the metal powder composition in step 1 is approximately 60% Fe, 25% Cu, 5% Sn, 10% Ni, and the diamond particle size is 80 mesh.

[0013] As a preferred embodiment, the target temperature in step 3 is 900~950℃.

[0014] As a preferred embodiment, the target duration of step 3 is 30-45 minutes.

[0015] As a preferred embodiment, in step 3, during microwave sintering, a diamond tool is pressed using carbon powder and a silicon carbide plate is used to assist in sintering.

[0016] This invention achieves indirect heating of the metal matrix by directionally arranging diamonds in a diamond tool blank and controlling the appropriate diamond particle spacing. If the diamond particle spacing is too large, the indirect heating efficiency of the metal matrix will be too low, affecting the strength of the diamond tool; if the spacing is too small, it will increase the cost of the diamond tool. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the spatial distribution of diamond particles in odd-numbered layers.

[0018] Figure 2 This is a schematic diagram of the spatial distribution of diamond particles in even-numbered layers.

[0019] Figure 3 This is an SEM image of a sample obtained using the orientation method described in this patent. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0021] like Figure 1 (Odd-numbered layers) Figure 2 As shown in the even-numbered layers, indirect heating of the metal matrix is ​​achieved through the rationally oriented arrangement of diamond particles. Excessive spacing between the diamond particles will result in low indirect heating efficiency of the metal matrix, affecting the strength of the diamond tool; conversely, insufficient spacing will increase the cost of the diamond tool.

[0022] Example 1:

[0023] This embodiment of a novel microwave sintering method for oriented diamond tools includes the following steps:

[0024] Step 1: Press the embryo;

[0025] Metal powders such as Fe, Cu, and Ni are added to an automatic pressing machine and pressed into a cuboid blank according to the directional arrangement described above. The blank has dimensions of 24×12×5mm, with the long side spanning 24mm consisting of an arc with a diameter of 350mm. Specifically, four layers of 80-mesh diamond particles are placed in the metal matrix, each layer arranged in 13 rows and 5 columns, with adjacent layers staggered. The distance between diamond particles is 1.770mm, the vertical distance between layers is 1.520mm, and the distance from the edge of the metal matrix to the nearest diamond particle is 1.385mm. Odd-numbered layers of diamond particles are arranged symmetrically according to the geometric symmetry axis of their respective cross-sections.

[0026] Step 2: Filling the green blanks:

[0027] Place the green body in a crucible and add carbon powder until the green body is completely buried.

[0028] Step 3: Microwave sintering

[0029] The crucible was placed in a microwave sintering apparatus, and a silicon carbide plate was placed on top for auxiliary heating. After heating to 900℃ and holding at that temperature for 30 minutes, the material was cooled in the furnace to obtain a diamond cutting tip.

[0030] Figure 3This is a SEM image of the oriented diamond tool from Example 1. The results show that the bonding between the diamond and the metal matrix is ​​relatively tight, and the density is good.

[0031] from Figure 3 Further analysis reveals that the novel microwave sintering method for oriented diamond tools described in this patent strengthens the bond between the diamond and the metal matrix, increasing the degree of powder densification. The bond between the diamond and the metal matrix, as well as the degree of powder densification, are crucial to the quality of diamond tools, indicating that the sintering method provided by this invention offers the most suitable sintering conditions possible for diamond tools.

[0032] The technical solutions of the present invention are not limited to the specific embodiments described above. Any technical modifications made in accordance with the technical solutions of the present invention fall within the protection scope of the present invention.

Claims

1. A novel microwave sintering method for directional alignment of diamond tools, characterized in that, The steps specifically include: Step 1.1: Select the optimal diamond orientation arrangement, add metal powder and diamond particles to an automatic pressing device to make a diamond tool blank. Step 1.2: Place the diamond tool blank into a ceramic crucible and then into a microwave sintering device. Step 1.3: Place the diamond tool blank into the microwave sintering equipment, heat it to the specified temperature, switch to the heat preservation mode, maintain the temperature for the target time, and then turn off the power and allow it to cool naturally to room temperature.

2. A novel microwave sintering method for the directional alignment of diamond tools as claimed in claim 1, wherein: The blank size of the cutter head in step 1.1 is 24×12×5mm, where the long side with a span of 24mm is composed of an arc with a diameter of 350mm.

3. A novel microwave sintering method for the directional alignment of diamond tools as claimed in claim 1, wherein: The directional arrangement is as follows: four layers of 80-mesh diamond particles are placed inside the cutting head blank, with each layer arranged in 13 rows and 5 columns, and adjacent layers are staggered. The distance between the diamond particles is 1.770 mm, the vertical distance between layers is 1.520 mm, and the distance from the edge of the metal matrix to the nearest diamond particle is 1.385 mm. Odd-numbered layers of diamond particles are arranged symmetrically according to the geometric symmetry axis of their respective cross-sections.

4. A novel microwave sintering method for the directional alignment of diamond tools as claimed in claim 1, wherein: The target temperature is 900~950℃.

5. A novel microwave sintering method for the directional alignment of diamond tools as claimed in claim 1, wherein: The target duration is 30-45 minutes.

6. A novel microwave sintering method for oriented diamond tools according to claim 1, characterized in that: In the microwave sintering process, carbon powder is used to embed diamond tools for pressing, and silicon carbide plates are used to assist in sintering.

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