Brazed grinding wheel based on cemented carbide-diamond film particles as abrasive and its manufacturing method

Abstract

The present invention provides a method for preparing a brazed grinding wheel based on cemented carbide-diamond film particles as abrasives, comprising the following steps: 1) preparing a diamond film on the end face of a cemented carbide substrate to obtain an abrasive; wherein the ratio of the thickness of the diamond film to the thickness of the cemented carbide substrate is 1:10-30; 2) installing the abrasive on the mounting hole of a grinding wheel substrate to which a brazing material is added, and brazing is performed. The grinding wheel prepared by the present invention avoids the defect that the diamond particles in the traditional manufacturing technology do not form a strong chemical bond with the metal matrix, resulting in a low bonding strength between the diamond abrasive and the metal matrix, and at the same time, the installation direction of the diamond particles with the best processing efficiency can be ensured, and its processing efficiency and service life are greatly superior to those of traditional diamond grinding wheels.

Description

Technical Field

[0001] The invention belongs to the technical field of grinding wheel preparation, and in particular relates to a method for preparing a brazed grinding wheel based on cemented carbide-diamond film particles as abrasives. Background Art

[0002] At present, the main bonding methods of diamond grinding wheels include: multi-layer sintered grinding wheels, electroplated grinding wheels and brazed grinding wheels:

[0003] (1) Sintered diamond grinding wheel. It is the earliest type of grinding wheel. It is mainly manufactured by high-temperature sintering. The binder is mainly bronze and other metals. It has many advantages such as convenient molding and the ability to process complex parts. It is widely used in grinding various materials. However, with the development of grinding technology, its defects have gradually been exposed, mainly in the following three aspects:

[0004] a. Since sintering is to process the workpiece as a whole at high temperature, there is a large degree of matrix deformation, and the grinding accuracy of the grinding wheel is greatly reduced;

[0005] b. In principle, sintered diamond grinding wheels only embed diamond abrasive grains in a binder. As the grinding force gradually increases, the diamond abrasive grains tend to fall off as a whole, eventually leading to the failure of the grinding wheel [1]. Therefore, multi-layer sintered diamond grinding wheels are very likely to fall off as a whole during heavy-load grinding, which makes the application of diamond abrasives unable to be fully utilized in the grinding process.

[0006] c. The abrasive of sintered diamond grinding wheel is diamond particles. The hardness and wear resistance of diamond particles are anisotropic, but the arrangement direction of diamond particles in the sintered grinding wheel is randomly distributed, so the best processing efficiency of diamond particles cannot be exerted.

[0007] (2) Electroplated diamond grinding wheel. Electroplated diamond grinding wheel is made by electrochemical method. It uses a processed metal grinding wheel substrate, which goes through pre-treatment, sanding, electroplating and other processes. During the electroplating process, diamond particles are embedded in the plated metal to form a diamond grinding wheel.

[0008] Since the overall high-temperature processing is avoided, there is no deformation, the forming accuracy is higher than that of sintered grinding wheels, and no dressing is required. Therefore, it is widely used in the high-efficiency grinding process at home and abroad. For example, GE in the United States uses electroplated grinding wheels to process alloy steel, and Litton Industrial Manufacturing Company in the United States uses electroplated grinding wheels to process automotive parts [2].

[0009] However, as electroplated diamond grinding wheels are widely used, their disadvantages are gradually exposed. Studies have shown that the diamond abrasive, coating alloy and matrix on the electroplated grinding wheel do not form a true metallurgical bond, and a large amount of abrasive is embedded in the matrix or embedded in the solder. As a result, the bonding strength is greatly weakened, the abrasive holding particle size is small, and the grinding wheel is also prone to failure due to the shedding of abrasive particles during heavy-load grinding. At the same time, the arrangement direction of diamond particles in the electroplated diamond grinding wheel is also randomly distributed, which also cannot exert the best processing efficiency of diamond particles.

[0010] Therefore, the diamond abrasive, brazing filler metal and grinding wheel matrix of traditional sintered and electroplated diamond grinding wheels are only mechanically embedded and embedded, resulting in low bonding strength among the abrasive, brazing filler metal and matrix. Therefore, sintered diamond grinding wheels and electroplated diamond grinding wheels are very likely to fall off as a whole during heavy-load grinding, which makes it impossible to give full play to the application of superhard abrasives in the high-efficiency grinding process.

[0011] In order to improve the bonding strength of the electroplated grinding wheel, the embedding depth can be increased, but as the embedding depth increases, the exposed height of the superhard abrasive decreases, resulting in a reduction in the chip space during the grinding process. When the grinding chips continue to increase, the grinding wheel is prone to clogging, the grinding performance will decrease, and even defects such as grinding burns will occur.

[0012] In order to improve the bonding strength between diamond abrasive, brazing alloy and metal grinding wheel substrate, some domestic and foreign scholars have made preliminary explorations in metallizing the abrasive surface[3] and adding some active elements to the brazing alloy[4]. However, no significant progress has been made in improving the bonding strength. Therefore, only by finding a method that can fundamentally change the bonding strength between abrasive, brazing alloy and substrate can the advantages of superhard abrasives in high-efficiency grinding technology be fully utilized.

[0013] (3) High temperature vacuum brazing diamond grinding wheel

[0014] In order to meet the technical requirements of grinding workpieces (high grinding efficiency, small workpiece surface roughness, etc.), the bonding method of superhard abrasives and grinding wheel substrates has been continuously improved and developed. It was not until the mid-to-late 1990s that domestic and foreign experts and scholars began to pay attention to the use of high-temperature vacuum brazing for the production of diamond grinding wheels. Through the dissolution, diffusion, and chemical reactions at the interface between the abrasive, brazing material, and steel substrate, the binder layer can firmly hold the abrasive, making the diamond abrasive and the metal grinding wheel substrate have a higher brazing bonding strength [5-6].

[0015] However, diamond is difficult to be wetted by most brazing materials, and diamond has poor thermal stability and a low linear expansion coefficient (1.2×10 -6 ~4.5×10 -6), thermal stress is easily generated during brazing [7-8]. Therefore, a large number of scholars have devoted their energy to systematically experiment and study the brazing technology of diamond, in order to achieve a breakthrough in the production of diamond brazing tools.

[0016] For example, AK Chattopadhyay et al. in Switzerland evenly coated NiCrFeSiB brazing material with an oxygen content of 0.5% on the surface of the steel substrate, and then arranged diamond abrasive grains on the alloy layer. They used flame spraying method to protect the argon atmosphere environment, and carried out high-frequency induction brazing under the conditions of heating temperature of 1080℃ and holding time of 30 seconds[9]. Yao Zhengjun et al. from Nanjing University of Aeronautics and Astronautics used self-developed Ni-Cr alloy powder to carry out diamond high-temperature brazing in an Ar gas protection radiation furnace

[10] . Ma Chufan et al. used Cr powder + NiCr13P4 alloy as brazing material to braze diamond abrasive grains on the surface of the steel substrate, with a brazing temperature of 950℃ and a vacuum degree of 0.2Pa

[11] .

[0017] FAKhalid et al. used Cu-Sn-Ti alloy powder to vacuum braze diamond, and used scanning electron microscopy and other methods to analyze the interface bonding composition and morphology. The results showed that there was obvious stratification at the bonding interface, and the TiC structure close to the abrasive side was cubic and discontinuous

[12] . Guo Zhaocui et al. from Nanjing University of Aeronautics and Astronautics used (Cu90Sn10)85Ti15 alloy powder to braze uncoated diamond at a heating temperature of 900℃ and a heat preservation time of 8min, and conducted a microstructure analysis of the interface between diamond and brazing alloy. TYamazak and JT Lower et al. used Ag-based brazing filler metal with added elements such as Ti, In, and V to vacuum braze diamond tools under certain process parameters to replace the diamond tools prepared by traditional electroplating method[13-14]. Guan Yancong et al. used copper-based brazing filler metal to vacuum braze diamond on the surface of steel substrate and analyzed the effect of different brazing temperatures on the interface structure and bonding strength. The results showed that in order to achieve better brazing effect, the heating temperature should be maintained between 880 and 930 °C and the holding time should be about 10 minutes

[15] .

[0018] During high-temperature vacuum brazing, the brazing material, diamond and the catalyst metal inside have different thermal expansion coefficients, which results in large residual stresses at the abrasive grains and the bonding interface. The brazing material will chemically corrode the diamond surface, causing a significant decrease in its mechanical properties. In addition, the abrasive grains may crack. Therefore, although the research and development of high-temperature brazing diamond technology has a history of several decades, how to apply this technology to production practice is still under continuous research.

[0019] In order to solve the problem of low bonding strength between diamond abrasives and metal matrix, previous products mainly adopted the following technical approaches:

[0020] 1. Improve the sintering process. The diamond surface is metallized during the sintering process to improve the bonding strength with the matrix, that is, strong carbide metal powder is added to the matrix material or pre-bonded on the diamond surface, in the hope that they can achieve chemical bonding to the diamond during the sintering process. However, from the perspective of the process used to achieve pre-metallization of the diamond surface, it is necessary to heat at a temperature of more than 600°C for 1 hour under vacuum conditions to obtain the ideal bonding force. According to the sintering conditions of the currently commonly used impregnated diamond cutting tools, heating at no more than 900°C for about 5 minutes in a non-vacuum or low vacuum cannot form a metallized layer on the diamond surface. Because whether the active metal atoms (Ti, V, Cr, etc.) are enriched on the diamond surface or the interface reaction achieves metallurgical bonding between the binder and the diamond, it is an atomic diffusion process. According to the temperature used for hot pressing and such a short time, this process is extremely insufficient. Under solid-phase sintering conditions (sometimes with a small amount of low-strength and low-melting-point metal or alloy liquid phase), the chemical bonding or metallurgical bonding of the matrix to the diamond is very weak or will not be formed at all. Therefore, this technical route has very limited effect on improving the performance of diamond grinding wheels.

[0021] 2. Brazing technology is used to make diamond grinding wheels. Certain transition elements (such as Ti, Cr, W, etc.) are plated on the surface of diamond, and chemically react with them to form carbides on the surface. Through the action of this layer of carbide, the diamond, binder, and matrix can achieve a firm chemical metallurgical bond through brazing, thereby achieving true diamond surface metallization. This is the principle of diamond brazing. It can be seen from the published patents and articles that this technology can make the maximum diamond edge value reach 2 / 3 of the particle size, and the tool life is increased by more than 3 times, while the value is less than 1 / 3 under normal circumstances. Therefore, the use of brazing technology is expected to achieve a firm bond between the matrix metal (brazine) and the parent material-diamond and steel matrix.

[0022] However, there are many difficulties that need to be solved urgently when brazing diamond: (1) The brazing material is required to have good wettability and bonding strength to the diamond and the matrix; (2) The selection of brazing materials and brazing processes must ensure the stability of diamond to reduce or avoid the erosion of diamond by the brazing material; (3) Due to the large difference in the thermal expansion coefficients of diamond and metal matrix, the welding residual stress is also large, which reduces the strength of the joint; (4) The melting point of the brazing material must be higher than the working temperature of the diamond tool, so metal (alloy) materials with a lower melting point and a close expansion coefficient to diamond should be found as brazing materials, and then some active elements should be added to improve the wettability and affinity to diamond, so as to achieve the purpose of bonding diamond and meeting the mechanical properties of the matrix. In addition, key technologies such as the realization method of diamond surface metallization, the matching and selection of surface metal and brazing material, and the selection of brazing agent and gas medium need to be further matured and optimized. In addition, the efficiency and life of diamond tools depend not only on the firmness of the diamond abrasives being embedded, but also on the wear resistance of the matrix. The strength of the matrix itself, the distribution of diamonds in the matrix, the concentration of diamonds, etc. will all affect the wear resistance of the matrix. Therefore, how to make the matrix reach an ideal state is also a problem worthy of attention in future work. Therefore, although the research on brazing technology began in the late 1980s, it is still in the experimental stage due to the complexity of the work, and its application is limited to single-layer tools. The research on high-temperature brazing technology in China started late. Compared with developed countries, the breadth and depth of the research are far from enough. Therefore, the current progress is very slow, and large-scale production and application have not yet been carried out. In addition, this technical route also cannot solve the problem of the installation direction of diamond particles, so it cannot give full play to the best performance of diamond particles.

[0023] The literature cited in the above background technology introduction is summarized as follows:

[0024] [1]Sung JC,Sung M.The brazing of diamond[J].International Journal of Refractory Matals and HardMaterials,2009,27(2):382-393.

[0025] [2] Fu Yucan, Xu Hongjun. From electroplating to brazing: New developments in the manufacturing technology of single-layer super-hard abrasive grinding wheels abroad [J]. Tool Technology, 1998, 32(8): 4-8.

[0026] [3]Wang YH, Zang JB, Wang MZ, et al. Properties and applications of Ti-coated diamond grits[J]. Journal of Materials Processing Technology, 2002, 129(1-3): 369-372.

[0027] [4] Song Yueqing, Xia Zhihua, Gan Changyan, et al. Study on the mechanism of action of rare earth element lanthanum in diamond tool matrix materials [J]. Rare Metals, 1998, 22(1): 39-42.

[0028] [5] Ding Lanying, Fu Yucan, Chen Yan, et al. Study on brazing fine-grained diamond with Ag-Cu-Ti / TiC composite brazing filler metal. Journal of Synthetic Crystals, 2013, 42(8): 1510-1514.

[0029] [6] Xu Jiuhua, Mou Juan, Chen Yan, et al. Research on CFRP hole making by brazed diamond drill. Journal of Nanjing University of Aeronautics and Astronautics, 2012, 44(5): 747-753.

[0030] [7] Guan Yancong, Chen Yuquan, Yao Deming, et al. Research and development of brazing filler metal for diamond abrasive and its brazing process. Transactions of the Chinese Society of Agricultural Machinery, 2005, 36(7): 140-143.

[0031] [8] Xiao Bing, Wu Zhibin, Xu Hongjun, et al. Study on brazing single-layer diamond grinding wheel with silver-based brazing filler metal. Diamond and Abrasives Engineering, 2001, 121(1): 4-7

[0032] [9] AK Chattopadhyay, L. Chollet and HE Hintermann. Induction brazing of diamond with Ni-Cr hardfacing alloy under argon atmosphere. Surface and Coating Technology, 1990, 45: 293-298

[0033]

[10] Yao Zhengjun, Xu Hongjun, Xiao Bing, et al. Study on the mechanism of Ni-Cr alloy brazing diamond grinding wheel. Transactions of the Chinese Society of Agricultural Machinery, 2001, 32(4): 96-98

[0034]

[11] Ma Chufan, Wang Zhongyi, Nan Junma, et al. Development of a dental single-layer high-temperature brazed diamond grinding wheel. Diamond and Abrasives Engineering, 2002, (2): 34-35

[0035]

[12] FAKhalid,UEKlotz.On the interfacial nanostructure ofbrazeddiamond grits.Scripta

[0036]

[13] T.Yamazaki,A.Suzumura.Relationship between X-ray diffraction and unidirectional solidification at interface between diamond and brazingfillermetal.Journal ofMaterials Science,2000,35:6144-6160

[0037]

[14] JTLower.Method of making monolayer abrasive tools.US,5492771,1996,2-20

[0038]

[15] Guan Yancong, Zheng Minli, Yao Deming, et al. Interface structure and strength of diamond welded with copper-based brazing filler metal. Journal of the China Welding Society, 2012, 33(7): 65-68. Summary of the invention

[0039] In view of the shortcomings of the prior art, one of the objects of the present invention is to provide a brazed grinding wheel with better grinding performance and a preparation method thereof.

[0040] In order to achieve the above object, the solution provided by the present invention is as follows:

[0041] A method for preparing a brazing grinding wheel based on cemented carbide-diamond film particles as abrasives, characterized in that the method comprises the following steps:

[0042] 1) preparing a diamond film on the end surface of a cemented carbide substrate to obtain an abrasive; wherein the ratio of the thickness of the diamond film to the thickness of the cemented carbide substrate is 1:10-30;

[0043] 2) mounting the abrasive on the mounting hole of the grinding wheel matrix to which the brazing material is added, and brazing is performed;

[0044] The abrasive is a cube with a side length of 2-5 mm or a cylinder with a diameter and height of 2-5 mm; the cemented carbide substrate is synthesized by powder metallurgy from WC particles and Co binder;

[0045] The mounting holes are located on the side of the grinding wheel base, arranged in an array, and the hole depth is 1mm.

[0046] Preferably, in step 1), the grade of cemented carbide in the cemented carbide matrix is ​​YG6.

[0047] Preferably, in step 2), the brazing material is nickel-based alloy powder.

[0048] Preferably, in step 2), before installing the abrasive, an adhesive is pre-added to the installation hole.

[0049] Preferably, the abrasive is a cube with a side length of 3 mm or a cylinder with a diameter and a height of 3 mm.

[0050] Preferably, during brazing, a high-frequency welding machine is used, the brazing power is 7 kW, the brazing time is 28 s, the vacuum cooling is 1.5 h, and the vacuum degree is 10 Pa.

[0051] Preferably, the grinding wheel substrate is made of 45# steel, has a diameter of 100 mm, a width of 6 mm, and a center hole diameter of 20 mm.

[0052] Preferably, in step 1), when preparing the diamond film, a chemical vapor deposition method is used in a hot wire CVD device.

[0053] Preferably, hydrogen and methane are used as raw gas, and a diamond film is deposited on the cemented carbide substrate after being excited by a hot wire at a high temperature of 2000°C.

[0054] Preferably, when depositing the diamond film, the diamond particles used have a particle size of 5 μm to 30 μm.

[0055] This patent uses formed cemented carbide raw materials as the matrix (cylinder or cuboid), and uses chemical vapor deposition method on the end face to produce cemented carbide-diamond film particle abrasives with high bonding strength. The particle size and thickness of the diamond film are adjusted through the process, and the appearance of the crystal surface is controlled through the process. The diamond-hard alloy composite abrasive is then installed in the mounting hole of the matrix made of steel or alloy, and then the diamond-hard alloy composite abrasive is firmly assembled on the metal matrix through brazing to complete the production of the diamond film brazed grinding wheel with cemented carbide matrix. Therefore, the overall shedding of the abrasive will not occur during the use of this diamond grinding wheel, and at the same time, the installation direction of the diamond particles with the best processing efficiency can be guaranteed. Its processing efficiency and service life are much better than those of traditional diamond grinding wheels.

[0056] Beneficial effects of the present invention:

[0057] The grinding wheel prepared by the present invention avoids the defect of low bonding strength between diamond abrasive and metal matrix caused by the failure of diamond particles to form a strong chemical bond with the metal matrix in the traditional manufacturing technology, and at the same time can ensure the installation direction of diamond particles with the best processing efficiency, and its processing efficiency and service life are greatly better than those of traditional diamond grinding wheels.

[0058] Instruction Manual

[0059] Figure 1 It is a schematic diagram of the outer dimensions of the grinding wheel base;

[0060] Figure 2 It is a schematic diagram of the outer circle shape and size of the grinding wheel base;

[0061] Figure 3 Schematic diagram of the arrangement of the hole array of the grinding wheel matrix;

[0062] Figure 4 A schematic diagram of a hot wire CVD device used in the present invention;

[0063] Figure 5 Schematic diagram of the appearance of cemented carbide-diamond film particles;

[0064] Figure 6 This is the appearance diagram of cemented carbide-diamond film particles;

[0065] Figure 7 Scanning electron microscope photo of diamond film;

[0066] Figure 8 and Fig. 9 This is the graph showing the variation of grinding force with Vs when grinding marble with different grinding wheels;

[0067] Fig.10 and Fig.11 This is the graph showing the variation of grinding force with Vs when different grinding wheels are grinding engineering plastics;

[0068] Fig.12 and Fig.13 This is the graph showing the variation of grinding force with Vs when grinding aluminum alloy with different grinding wheels;

[0069] Fig.14 and Fig.15 This is a graph showing the variation of grinding force with Vs when grinding cemented carbide with different grinding wheels. DETAILED DESCRIPTION

[0070] The present invention is described in detail below through examples. It is necessary to point out that the following examples are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by technical personnel in this field based on the above invention content still fall within the scope of protection of the present invention.

[0071] Example 1

[0072] (1) Preparation of grinding wheel matrix:

[0073] The material is 45# steel, processed into a shape with a diameter of 100mm, a width of 6mm, and a center hole diameter of 20mm as the grinding wheel base. Figure 1 As shown, an array of holes is machined on the outer circular wall, with a hole depth of 1.0 mm, for mounting carbide-diamond film abrasives, such as Figure 2 , Figure 3 shown.

[0074] (2) Preparation of abrasive

[0075] The carbide grade is YG6, which is formed by powder metallurgy and a small amount of processing to make a carbide abrasive matrix. The carbide abrasive matrix is ​​used to make a diamond film on the end surface by chemical vapor deposition in a hot wire CVD device. The main structure of the hot wire CVD device consists of a vacuum system, an air intake system, a heating system, and a sample loading and control system. Figure 4 As shown. The entire reaction chamber, pipeline, etc. are evacuated by a mechanical pump to achieve a vacuum state. The air intake system is composed of two stainless steel pipelines that merge into one and then enter the reaction chamber. The flow rate is controlled by a gas flow controller; the heating system is composed of electrodes, hot wires, and power supplies. The power supply is a constant power DC power supply, and the hot wire is heated to the set temperature through the electrode; the sample loading system is composed of a sample table, a lifting mechanism, and a fixture. Hydrogen and methane are used as raw gas, and a diamond film is deposited on the cemented carbide abrasive substrate after being excited by a hot wire at a high temperature of 2000°C. The thickness and grain size of the diamond film are controlled by process parameters such as hot wire temperature, cemented carbide abrasive substrate temperature, gas flow, pressure, and deposition time. The diamond film sample prepared on the end face of the cemented carbide abrasive substrate is shown in the figure. Figure 5 As shown, its appearance is Figure 6 , Figure 7 Shown is a micrograph of a diamond film.

[0076] (3) Installation

[0077] The prepared abrasives are installed in the mounting holes of the grinding wheel matrix. The mounting holes are pre-filled with powder alloy brazing materials containing a binder. The brazing material is nickel-based alloy powder. A high-frequency welding machine is used for brazing operation, with a maximum power of 50KW and a frequency of 30-80KHz. Brazing process: brazing power is 7KW, brazing time is 28s, vacuum cooling is 1.5h, and vacuum degree is 10Pa.

[0078] The machining performance comparison experiment was conducted on marble, plastic, aluminum alloy and hard alloy on the universal grinder. Under the same machining conditions, the normal force and tangential force are much smaller than those of sintered diamond grinding wheel and electroplated diamond grinding wheel. This shows that the performance of this patented product is significantly better than that of traditional diamond grinding wheel.

[0079] The grinding process was carried out on a universal tool grinder with variable frequency speed regulation. The grinding process parameters were as shown in Table 1. The test used a fixed grinding method and fixed grinding parameters to compare the grinding force change characteristics of the patented product with sintered diamond grinding wheel and electroplated residual diamond grinding wheel for grinding 4 different materials, and to conduct a comparative evaluation of the grinding performance of the patented carbide-diamond film brazed grinding wheel and the material adaptability evaluation.

[0080] Table 1 Processing parameter settings

[0081]

[0082] Depend on Figures 8 to 9 It can be seen that the three grinding wheels process four kinds of materials respectively, and the normal force and tangential force decrease with the increase of the grinding wheel linear speed. When grinding four kinds of materials, the grinding force of the sintered diamond grinding wheel increases significantly, the grinding force of the electroplated diamond grinding wheel is the second, and the grinding force of the cemented carbide-diamond film brazed grinding wheel is the smallest. This shows that this patent has the best grinding performance for multiple materials.

Claims

1. A method for preparing a brazing grinding wheel based on cemented carbide-diamond film particles as abrasive, characterized in that: The method comprises the following steps: 1) Preparing a diamond film on the end surface of a cemented carbide substrate to obtain an abrasive; wherein the ratio of the thickness of the diamond film to the thickness of the cemented carbide substrate is 1:10-30; 2) installing the abrasive on the mounting hole of the grinding wheel base body to which the brazing material is added, and performing brazing; The abrasive is a cube with a side length of 2-5 mm or a cylinder with a diameter and height of 2-5 mm; the cemented carbide substrate is synthesized by powder metallurgy from WC particles and Co binder; The mounting holes are located on the side of the grinding wheel base, arranged in an array, and the hole depth is 1 mm; In step 1), the grade of cemented carbide in the cemented carbide matrix is ​​YG6; In step 1), when preparing the diamond film, a chemical vapor deposition method is used in a hot wire CVD device; hydrogen and methane are used as raw gas, and a diamond film is deposited on a cemented carbide substrate after being excited by a hot wire at a high temperature of 2000°C; when depositing the diamond film, the particle size of the diamond particles used is 5μm-30μm; The grinding wheel base is made of 45# steel, with a diameter of 100mm, a width of 6mm, and a center hole diameter of 20mm; In step 2), the brazing material is nickel-based alloy powder; in step 2), before installing the abrasive, a binder is pre-added to the mounting hole; During brazing, a high-frequency welding machine is used with a brazing power of 7KW, a brazing time of 28s, vacuum cooling of 1.5h, and a vacuum degree of 10Pa.

2. The preparation method according to claim 1, characterized in that: The abrasive is a cube with a side length of 3 mm or a cylinder with a diameter and a height of 3 mm.

3. The brazing grinding wheel prepared by the preparation method according to claim 1 or 2.

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