Composite diamond grinding wheel for Ti-based metal ceramic cutter and preparation method of composite diamond grinding wheel

Abstract

The invention discloses a composite diamond grinding wheel for a Ti-based metal ceramic cutter and a preparation method of the composite diamond grinding wheel. Metal mixed powder and grinding materials are mixed and then sintered, an obtained sintered green body is smashed, and a metal grinding material compound is obtained; and resin powder and the metal abrasive compound are mixed and then subjected to hot press molding, and the composite diamond grinding wheel for resin and metal is obtained. According to the invention, the metal binding agent can firmly wrap the abrasive material, and the resin binding agent wraps the metal structure, so that an overall self-sharpening and local strong wrapping structure can be formed. In this way, when the Ti (C, N)-based metal ceramic cutter is subjected to grooving machining, the machining efficiency can be improved, meanwhile, good machining roughness, cutting edge chipping and microscopic lines can be achieved, the self-sharpening property of the grinding wheel can be exerted for continuous machining, the finishing interval is prolonged, and the ultrahigh grinding efficiency and machining quality are achieved in the machining process.

Description

Technical Field

[0001] This invention relates to the machining of metal ceramics, specifically to a composite bonded diamond grinding wheel for Ti(C,N)-based metal ceramic cutting tools, belonging to the field of diamond grinding wheels. Background Technology

[0002] The English word "cermet" or "ceramet" is a combination of "ceramic" and "metal." Cermet is a composite material, and its definition has varied slightly over time. For example, some define it as a material composed of ceramics and metals, or a composite material of ceramics and metals produced by powder metallurgy. Generally, it is defined as a material made from metal and ceramic raw materials, possessing certain advantages of both, such as the toughness and bending strength of the former and the high temperature resistance, high strength, and oxidation resistance of the latter. A more specialized definition is a heterogeneous composite material composed of a metal or alloy and one or more ceramic phases, where the latter accounts for 15% to 85% by volume, and the solubility between the metal and ceramic phases is relatively low at the preparation temperature. In a narrower sense, cermet refers to a class of materials in which the metal and ceramic phases have interfaces in three-dimensional space. In a broader sense, cermet also includes refractory compound alloys, cemented carbides, and metal-bonded diamond tool materials. In cermets, the ceramic phase is an oxide or refractory compound with a high melting point and high hardness, while the metallic phase is mainly transition elements (iron, cobalt, nickel, chromium, tungsten, molybdenum, etc.) and their alloys.

[0003] Metal-based cermets combine the toughness, high thermal conductivity, and good thermal stability of metals with the high-temperature resistance, corrosion resistance, and wear resistance of ceramics. Metal-based cermets typically exhibit high high-temperature strength, low density, ease of processing, corrosion resistance, and good thermal conductivity, and are commonly used in the manufacture of structural components for aircraft and missiles, engine pistons, and chemical machinery parts. Ceramic-based cermets can be further subdivided into the following types: 1. Oxide-based cermets. These are composites made from alumina, zirconium oxide, magnesium oxide, beryllium oxide, etc., combined with tungsten, chromium, or cobalt. They are characterized by high temperature resistance, chemical corrosion resistance, good thermal conductivity, and high mechanical strength. They can be used as missile nozzle liners, crucibles for smelting metals, and metal cutting tools.

[0004] 2. Carbide-based cermets. These are composites made from titanium carbide, silicon carbide, tungsten carbide, etc., combined with metals such as cobalt, nickel, chromium, tungsten, and molybdenum. They are characterized by high hardness, high wear resistance, and high temperature resistance, and are used to manufacture cutting tools, high-temperature bearings, sealing rings, wire pick-up die sleeves, and turbine blades.

[0005] 3. Nitride-based cermets. These are based on titanium nitride, boron nitride, silicon nitride, and tantalum nitride. They possess ultra-hardness, thermal shock resistance, and good high-temperature creep resistance, but their applications are relatively limited.

[0006] 4. Boride-based cermets. These are composites made by combining titanium boride, tantalum boride, vanadium boride, chromium boride, zirconium boride, tungsten boride, molybdenum boride, niobium boride, hafnium boride, etc., with some metallic materials as the matrix.

[0007] 5. Silicate-based cermets. These are composites made by combining manganese silicide, iron silicide, cobalt silicide, nickel silicide, titanium silicide, zirconium silicide, niobium silicide, vanadium silicide, niobium silicide, tantalum silicide, molybdenum silicide, tungsten silicide, barium silicide, etc., with some or trace amounts of metallic materials. Among them, molybdenum silicide cermets are widely used in industry.

[0008] 6. Carbonitride-based cermets. These materials are composed of Ti(C,N) as the main hard phase, MoC, WC, TaC, etc. as additives, and Ni as the binder metal. They are a new type of tool material that emerged in the 1970s. Compared with traditional cemented carbide, they have higher red hardness, wear resistance, heat resistance, resistance to crater wear, and a lower coefficient of friction, resulting in longer tool life.

[0009] Due to the numerous advantages of Ti(C,N)-based cermets, they are gradually replacing cemented carbide in the cutting tool industry. Research on them is particularly extensive in Japan, and by the early 1990s, Ti(C,N)-based cermet cutting tool materials already accounted for 30% of the total market share of all cutting tool materials.

[0010] The performance of Ti(C,N)-based cermet materials in the domestic market has surpassed that of imports from Europe, the United States, and Japan. The only factor restricting the expansion of the Ti(C,N)-based cermet material industry is the difficulty in processing it. Its processing efficiency is only 1 / 5 to 1 / 3 of that of cemented carbide, which greatly limits the application of cermet cutting tools.

[0011] Currently, the mainstream grinding wheels used for machining Ti(C,N)-based cermet tools are imported from Asahi in Japan, and their performance is the best. Domestically produced wheels are very rare. Therefore, there is a need to develop new grinding wheels for machining Ti(C,N)-based cermet tools. Summary of the Invention

[0012] The purpose of this invention is to provide a composite diamond grinding wheel for Ti(C,N)-based cermet cutting tools. This composite grinding wheel is obtained by high-temperature vacuum sintering of a metal-bonded diamond preform, followed by crushing and bonding with resin. The metal binder firmly encapsulates the abrasive, while the resin binder encapsulates the metal structure, forming a self-sharpening overall structure with strong localized encapsulation. When grooving Ti(C,N)-based cermet cutting tools, this invention's grinding wheel improves machining efficiency while achieving excellent surface roughness, reducing edge chipping and microtexture. It also leverages the wheel's self-sharpening properties for continuous machining, extending dressing intervals. It combines multiple advantages, exhibiting extremely high grinding efficiency and machining quality during the process.

[0013] To achieve the above objectives, the specific technical solution of the present invention is as follows: A Ti-based cermet tool composite diamond grinding wheel includes a grinding layer comprising a resin and a metal abrasive composite; the metal abrasive composite is obtained by sintering a metal mixed powder and abrasive; the metal mixed powder includes Cu, Sn, Ag and carbon materials.

[0014] This invention discloses a method for preparing the above-mentioned composite diamond grinding wheel for Ti-based cermet cutting tools, comprising the following steps: (1) The metal mixture powder and abrasive are mixed and sintered, and then the sintered blank is crushed to obtain a metal abrasive composite. (2) The resin powder and the metal abrasive composite are mixed and hot-pressed to obtain a composite diamond grinding wheel for Ti-based metal ceramic cutting tools.

[0015] In this invention, a metal-bonded diamond preform is obtained by high-temperature vacuum sintering, and then crushed to obtain a metal-abrasive composite material. The sintering temperature profile is as follows: temperature rises from room temperature to 250–350°C over 0.1–1 hour, holds for 0.5–1.5 hours, then rises to 500–600°C over 0.1–1 hour, and holds for 1–2 hours. The hot-pressing pressure is 20–80 MPa. In this invention, the grinding layer is prepared by hot pressing of resin powder and metal abrasive composite. Preferably, the temperature curve of hot pressing is as follows: the temperature is raised from room temperature to 200-250°C in 5-10 minutes, held for 10-20 minutes, then raised to 320-350°C in 5-10 minutes, and held for 40-60 minutes.

[0016] In this invention, the resin powder is modified polyimide resin powder; specifically, conventional technology is used.

[0017] In this invention, the metal mixed powder is composed of copper powder, tin powder, silver powder and graphite powder; the weight ratio of copper powder, tin powder, silver powder and graphite powder is (45-50): (45-50): (2-8): (0.5-1.5).

[0018] Preferably, the copper powder and tin powder have the same weight.

[0019] In this invention, the abrasive is diamond.

[0020] In this invention, the volume ratio of metal mixed powder to abrasive is (68-75):(25-32); the volume ratio of resin powder to metal abrasive composite is (50-60):(40-50).

[0021] This invention discloses the application of the above-mentioned composite diamond grinding wheel for Ti-based cermet cutting tools in the machining of Ti-based cermets.

[0022] This invention discloses a method for machining Ti-based cermet tools, comprising the following steps: using the aforementioned Ti-based cermet tools to create grooves with a composite diamond grinding wheel to achieve the machining of Ti-based cermet tools.

[0023] This invention describes a grooving process. Compared to face grinding, grooving places different demands on the grinding wheel. Current production experience shows that ceramic-bonded grinding wheels are unsuitable for grooving, while metal or resin grinding wheels each have their own drawbacks. This invention discloses a Ti(C,N)-based cermet-ceramic composite diamond grinding wheel for cutting tools, whose grinding layer comprises resin and a metal abrasive composite; the metal abrasive composite is obtained by sintering metal mixed powder and abrasive. As is common knowledge, grinding wheels also contain a matrix. Specifically, the Ti(C,N)-based cermet-ceramic composite diamond grinding wheel for cutting tools consists of a matrix and a grinding layer disposed on the matrix, a structure that is conventional.

[0024] In this invention, the grinding layer is prepared from resin powder and metal abrasive composite; the abrasive is artificial industrial diamond.

[0025] This invention involves mixing and sintering a metal abrasive powder, then pulverizing the resulting sintered blank to obtain a metal-abrasive composite. Resin powder is then mixed with the metal-abrasive composite and hot-pressed to obtain a Ti(C,N)-based cermet composite diamond grinding wheel for cutting tools. As is common practice, mixing resin powder with a metal abrasive composite, hot-pressing, and then performing conventional machining yields a Ti(C,N)-based cermet composite diamond grinding wheel for cutting tools.

[0026] In this invention, the sintering temperature curve is as follows: the temperature is increased from room temperature to 300°C over 0.5 hours, held for 1 hour, then increased to 500–600°C over 0.5 hours, held for 1–2 hours, and then the mold is rapidly cooled in cold water. Crushing is achieved using a ball milling method after crushing. Preferably, the metal mixture powder and abrasive are mixed, cold-pressed, and then sintered. More preferably, the metal mixture powder and abrasive are mixed, sieved, cold-pressed, and then sintered. Preferably, the sintering is vacuum sintering.

[0027] In this invention, the obtained sintered green body is crushed and sieved to obtain a metal abrasive composite; the resin powder and the metal abrasive composite are mixed and sieved, and then hot-pressed into shape.

[0028] In this invention, the hot pressing pressure is 20-80 MPa; the hot pressing temperature curve is as follows: the temperature is raised from room temperature to 220°C in 5-10 minutes, held for 10-20 minutes, then raised to 320-350°C in 5-10 minutes, held for 40-60 minutes, and then cooled naturally.

[0029] In this invention, the volume ratio of metal mixed powder to abrasive is (68-75):(25-32); the volume ratio of resin powder to metal abrasive composite is (50-60):(40-50).

[0030] As an example, the metal mixed powder is composed of the following components in the following weight ratio: Cu 47%, Sn 47%, Ag 5%, and graphite 1%.

[0031] In this invention, the resin powder is modified polyimide resin powder, and the curing temperature is 350-400℃, which is an existing product.

[0032] This invention combines a metal binder and diamond abrasive, then mixes them with a resin binder to prepare a composite diamond grinding wheel. When used on a five-axis CNC machine tool for grooving Ti(C,N)-based cermet tools, it exhibits excellent sharpness and self-sharpening properties, enhancing overall matrix strength and extending wheel life. It also boasts superior surface finish, no burns on the tool body, fine surface roughness and texture, and a defect-free cutting edge. In short, it combines the advantages of high-quality machining, high efficiency, and long service life. When machining Ti(C,N)-based cermet tools, the single feed rate can reach 1.5–2.0 mm, an improvement of 50–100% compared to existing grinding wheels; the feed rate can reach 40–60 mm / min, an improvement of 100–200% compared to existing grinding wheels; the dressing interval is 400–500 pieces, an improvement of 100–150% compared to existing grinding wheels; and the service life is improved by 200–300% compared to existing grinding wheels. Under the same testing conditions, the composite bonded diamond grinding wheel of the present invention improves the overall processing efficiency by 300-400% compared with the resin grinding wheel on the market.

[0033] Due to the application of the above-described solution, the present invention has the following advantages compared with the prior art: 1. This invention combines a metal binder and diamond abrasive, and then mixes them with a resin binder to prepare a composite diamond grinding wheel, which has the advantages of processing quality, processing efficiency and processing life, and has ultra-high grinding efficiency during the processing.

[0034] 2. The composite diamond grinding wheel prepared using the method of this invention has a metal binder that firmly encapsulates the abrasive, while the resin binder fills and encapsulates the metal structure, forming an overall self-sharpening and locally strongly encapsulated structure. During processing, it combines sharpness and self-sharpening properties, while also exhibiting better edge retention and lifespan, thus improving overall processing efficiency.

[0035] 3. The composite diamond grinding wheel disclosed in this invention has excellent performance. Compared with similar grinding wheels currently in production and application, under the same test conditions, the single feed rate can be increased by 50-100%; the feed speed can be increased by 100-200%; the dressing interval can be increased by 100-150%; the service life can be increased by 200-300%; and the overall processing efficiency can be increased by 300-400%.

[0036] 4. The composite bond diamond grinding wheel disclosed in this invention has a simple preparation process, high production efficiency, no special requirements for raw materials, and does not cause pollution to the environment during the production process, making it suitable for industrial production and application. Attached Figure Description

[0037] Figure 1 Photos of Ti(C,N)-based cermets before and after grooving (not the same piece).

[0038] Figure 2 This is a microstructure image of the grinding wheel in Example 1.

[0039] Figure 3 The image shows the grinding wheel used in Example 1.

[0040] Figure 4 This is an image of a workpiece processed in Example 1, with a scale of 200 micrometers.

[0041] Figure 5 The image shows a workpiece being processed, with a scale of 200 micrometers.

[0042] Figure 6 The image shows a workpiece processed as a comparative example, with a scale of 200 micrometers. Detailed Implementation

[0043] In current industrial applications, resin-bonded diamond wheels are primarily used for grooving cermet tools. However, during the machining of cermet materials, metal-bonded diamond wheels frequently encounter serious problems such as machine tool vibration after dulling, cracking, chipping, and even workpiece breakage. They also tend to accumulate chips, making continuous machining impossible. Furthermore, ceramic-bonded wheels have poor shape retention, making it difficult to maintain tool dimensions. The high machine tool load and smoke generation also contribute to their undesirable operating conditions, making them rarely used for industrial machining of cermet tools. On the other hand, traditional resin-bonded diamond wheels are prone to wear, have poor shape retention, low grinding ratio, and low machining efficiency when grinding cermet materials. These issues, including tool burning and chipping, limit the application of resin-bonded wheels in this field.

[0044] Existing grinding wheels still need improvement in their performance for grooving Ti(C,N)-based cermets, especially the mainstream resin-bonded wheels which have low processing efficiency and are prone to tool burn-in and chipping. This invention develops a new grinding wheel for machining Ti(C,N)-based cermet tools, which can maintain the sharpness of the grinding wheel and improve processing efficiency. Simultaneously, it achieves excellent surface roughness, reduces edge chipping and microtexture, and leverages the self-sharpening properties of the grinding wheel for continuous processing, extending dressing intervals. Combining the advantages of both, it exhibits extremely high grinding efficiency and machining quality during the processing.

[0045] The method for preparing the above-mentioned Ti(C,N)-based cermet tool composite diamond grinding wheel disclosed in this invention includes the following steps: (1) Mix metal powder and diamond abrasive, then cold press to form a metal blank, and then sinter it in a vacuum sintering furnace to obtain a metal blank; (2) After the metal billet is crushed, it is placed in a planetary ball mill for ball milling to obtain a metal abrasive composite. (3) The resin powder is mixed with the metal abrasive composite to obtain a grinding wheel grinding layer mixture; (4) The grinding layer mixture is added to a mold with a matrix (conventional technology), and hot-pressed on a flat vulcanizing machine to obtain a grinding wheel molded body; (5) The grinding wheel is machined to obtain a Ti(C,N) based metal ceramic tool composite diamond grinding wheel.

[0046] Preferably, the preparation method of the above-mentioned Ti(C,N)-based cermet tool composite diamond grinding wheel includes the following steps: (1) Mix metal powder and diamond abrasive, sieve and cold press to form, sinter in vacuum sintering furnace to obtain metal billet; (2) After crushing the metal billet, it is placed in a planetary ball mill for ball milling, and then sieved to obtain a metal abrasive composite. (3) Mix the resin powder with the metal abrasive composite, sieve, and obtain the grinding wheel grinding layer mixture; (4) The grinding layer mixture is added to a mold with a matrix and hot-pressed on a flat vulcanizing machine to obtain a grinding wheel molded body; (5) The grinding wheel is processed by conventional machining to obtain a Ti(C,N) based metal ceramic cutting tool resin metal composite diamond grinding wheel.

[0047] In the above technical solution, in step (1), the mesh size of the sieve is 300-350 mesh; the cold pressing pressure is 90-120 MPa; the sintering temperature curve is: 0.5 h to 300℃, hold for 1 h, then 0.5 h to 500-600℃, hold for 1-2 h, and then quench in cold water; in step (2), the mesh size of the sieve is 60 or 80 mesh, and the material on the 80 mesh sieve is taken; the planetary ball mill speed is 200-500 rpm, and the ball milling time is 3-4 h; in step (3), the mesh size of the sieve is 50-70 mesh; in step (4), the hot pressing process curve is: pressure 20-80 MPa. MPa; 10 minutes to raise the temperature from room temperature to 220℃, hold for 15 minutes and then raise the temperature to 320~350℃ for 5 minutes, hold for 40~60 minutes and then cool with the furnace; In step (5), machining includes lathe machining and grinding machine machining.

[0048] In the above technical solution, by volume percentage, the metal blank is composed of 68-75% metal mixed powder and 25-32% diamond abrasive; in the grinding layer mixture, the volume percentages of resin powder and metal abrasive composite are 50-60% and 40-50%, respectively; the metal mixed powder is prepared by mixing the following components in the following weight ratio: Cu 47%, Sn 47%, Ag 5%, and graphite 1%; the resin powder is modified polyimide, and the curing temperature is 350-400℃.

[0049] This invention discloses the application of the above-mentioned Ti(C,N)-based cermet tool composite diamond grinding wheel in machining cermets. Preferably, the cermet is a Ti(C,N)-based cermet tool, and the machining is grooving.

[0050] This invention discloses a method for machining Ti(C,N)-based cermet tools, which utilizes the aforementioned Ti(C,N)-based cermet tools to perform grooving with a composite diamond grinding wheel, thereby realizing the machining of Ti(C,N)-based cermet tools.

[0051] The present invention will be further described below with reference to embodiments. The raw materials used in this invention are all commercially available products, and their properties meet the requirements for grinding wheel applications; for example, the diamond used is uncoated particle size 230 / 270, commercially available, and its quality meets national standards; the modified polyimide resin powder is grade P84 and is commercially available. The specific preparation operations and testing methods are conventional techniques.

[0052] Machining and testing were conducted using a five-axis CNC grinder to machine Ti(C,N)-based cermet (ST20) end mills for grooving tests. Figure 1 Photos before and after grooving Ti(C,N)-based cermets. By observing changes in equipment load and power, the appropriateness of the grinding wheel's feed rate and speed is determined; the grinding wheel's retention is assessed by the number of parts processed within a dressing cycle; and the grinding wheel's lifespan is determined by the final number of parts processed. Finally, the overall processing efficiency of the grinding wheel is evaluated based on its feed rate, dressing interval, and lifespan.

[0053] Comparison Example Commercially available resin grinding wheels are the mainstream products, with an actual feed rate of 1.0 mm, a feed speed of 20 mm / min, and a dressing interval of 200 wheels.

[0054] Preparation Example The metal mixed powder consists of 47% Cu, 47% Sn, 5% Ag, and 1% graphite. The four powders are mixed by conventional stirring to obtain the metal mixed powder.

[0055] Example 1 describes the preparation of a diamond-coated grinding wheel for Ti(C,N)-based cermet cutting tools, comprising the following steps: 1. Preparation of metal billet (1) By volume: 75% metal mixed powder and 25% diamond particles are mixed and passed through a 320-mesh standard sieve to obtain metal blank powder; (2) The metal blank powder is cold-pressed into shape on a cold press at a pressure of 100 MPa, and then in a 1×10 -2 Sintering was carried out in a vacuum sintering furnace of Pa. The sintering temperature curve was as follows: the temperature was raised from room temperature to 300℃ in 0.5 h, held for 1 h, then raised to 600℃ in 0.5 h, held for 2 h, and then quenched in water to obtain a metal billet.

[0056] 2. Preparation of grinding layer mixture (1) After crushing the metal billet, it is placed in a planetary ball mill and ball milled at 330 rpm for 3 h. Then, it is passed through a combination of 60 and 80 mesh sieves, and the particles between the 60 and 80 mesh sieves are selected to obtain the metal abrasive composite. (2) The modified polyimide resin powder and the metal abrasive composite are mixed in a three-dimensional mixer at a volume percentage of 60% and 40% for 1 hour, and then passed through a 60-mesh sieve. The material passing through the sieve is the grinding layer mixture.

[0057] 3. Preparation of composite diamond grinding wheels (1) The grinding layer mixture is conventionally added to the mold with the matrix, preheated on a flat vulcanizing machine at a pressure of 20 MPa, then hot-pressed at 80 MPa, heated from room temperature to 220°C in 10 minutes, held for 15 minutes, then heated to 320°C in 5 minutes, held for 60 minutes, and then cooled naturally. The grinding wheel is obtained by demolding. (2) According to conventional methods, the grinding wheel is machined on a lathe and a grinding machine to the shape and size required by the drawing. After passing the inspection according to the national standard JB / T 7425-94 for diamond grinding wheels, it is packaged and put into storage to obtain a composite diamond grinding wheel for Ti(C,N) based metal ceramic cutting tools. Figure 2 This is a microscopic image of the grinding wheel; Figure 3 This is a picture of the actual grinding wheel.

[0058] The actual feed rate of this grinding wheel reaches 1.5 mm, which is 50% higher than the existing mainstream grinding wheels; the feed speed is 40 mm / min, which is 100% higher than the existing mainstream grinding wheels; the dressing gap is 500 dressings, which is 150% higher than the existing mainstream grinding wheels; the service life is 300% higher than the existing mainstream grinding wheels; and the overall processing efficiency is increased by 300%.

[0059] See appendix Figure 4 The workpiece surface roughness, brightness, and texture produced by the grinding wheel of this invention are excellent, and the cutting edge of the tool is free from chipping and collapse under microscopic magnification. At the same time, the processing efficiency and lifespan of the product are greatly improved.

[0060] Example 2 describes the preparation of a diamond-coated grinding wheel for Ti(C,N)-based cermet cutting tools, comprising the following steps: 1. Preparation of metal blank: Refer to step (1) of Example 1, wherein the metal blank is obtained by volume ratio of 68% metal mixed powder and 32% diamond particles.

[0061] 2. Preparation of grinding layer mixture: Refer to step (2) of Example 1, wherein the modified polyimide resin powder and the metal abrasive composite are mixed in a three-dimensional mixer at 50% and 50% by volume for 1 hour, and then passed through a 60-mesh sieve. The material passing through the sieve is the grinding layer mixture.

[0062] 3. Preparation of composite diamond grinding wheels: (1) Add the grinding layer mixture to the mold with the matrix, preheat it on the flat vulcanizing machine at a pressure of 20 MPa, then press it up to 80 MPa for hot pressing, raise the temperature from room temperature to 220°C in 10 minutes, keep it at the temperature for 15 minutes, raise the temperature to 350°C in 10 minutes, keep it at the temperature for 50 minutes, and then cool it naturally. The grinding wheel is obtained by demolding. (2) The composite diamond grinding wheel for Ti(C,N) based metal ceramic cutting tools was obtained by machining and inspection according to conventional methods.

[0063] The actual feed rate of this grinding wheel reaches 2.0 mm, which is 100% higher than the existing mainstream grinding wheels; the feed speed is 60 mm / min, which is 200% higher than the existing mainstream grinding wheels; the dressing gap is 400 dressings, which is 100% higher than the existing mainstream grinding wheels; the service life is 200% higher than the existing mainstream grinding wheels; and the overall machining efficiency is increased by 400%.

[0064] Example 3 describes the preparation of a diamond-coated grinding wheel for Ti(C,N)-based cermet cutting tools, comprising the following steps: 1. Preparation of metal billet: (1) By volume: 70% metal mixed powder and 30% diamond particles are mixed and passed through a 320-mesh standard sieve to obtain metal blank powder; (2) The metal blank powder is cold-pressed into shape on a cold press at a pressure of 90 MPa, and then in a 1×10 -2 Sintering was carried out in a vacuum sintering furnace of Pa. The sintering temperature curve was as follows: the temperature was raised from room temperature to 300℃ in 0.5 h, held for 1 h, then raised to 550℃ in 0.5 h, held for 2 h, and then quenched in water to obtain a metal billet.

[0065] 2. Preparation of the grinding layer mixture: (1) After crushing the metal billet, it is placed in a planetary ball mill and ball milled at 330 rpm for 3 h. Then, it is passed through a combination of 60 and 80 mesh sieves, and the particles between the 60 and 80 mesh sieves are selected to obtain the metal abrasive composite. (2) The modified polyimide resin powder and the metal abrasive composite were mixed in a three-dimensional mixer at a volume percentage of 55% and 45% for 1 hour, and then passed through a 60-mesh sieve. The material passing through the sieve is the grinding layer mixture.

[0066] 3. Preparation of composite diamond grinding wheels: (1) Add the grinding layer mixture to the mold with the matrix, preheat it on the flat vulcanizing machine at a pressure of 20 MPa, then press it up to 80 MPa for hot pressing, raise the temperature from room temperature to 220°C in 10 minutes, keep it at the temperature for 15 minutes, raise the temperature to 330°C in 10 minutes, keep it at the temperature for 40 minutes, and then cool it naturally. The grinding wheel is obtained by demolding. (2) The composite diamond grinding wheel for Ti(C,N) based metal ceramic cutting tools was obtained by machining and inspection according to conventional methods.

[0067] The actual feed rate of this grinding wheel reaches 1.75 mm, which is 75% higher than the existing mainstream grinding wheels; the feed speed is 50 mm / min, which is 150% higher than the existing mainstream grinding wheels; the dressing gap is 400 dressings, which is 100% higher than the existing mainstream grinding wheels; the service life is 200% higher than the existing mainstream grinding wheels; and the overall processing efficiency is increased by 300%.

[0068] Comparative Example 1 involves the preparation of a metal-bonded diamond grinding wheel, comprising the following steps: (1) By volume: 70% metal mixed powder and 30% diamond particles are mixed and ball-milled, and then passed through a 320-mesh standard sieve to obtain metal blank powder; (2) The metal billet powder is loaded into a mold with a matrix, cold-pressed at 100 MPa on a cold press, and then sintered in a vacuum sintering furnace. The sintering temperature curve is: 0.5 h from room temperature to 300℃, hold for 1 h, then 0.5 h to 550℃, hold for 2 h, and then cool with the furnace to obtain the metal grinding wheel. (3) The diamond grinding wheel is obtained by machining and inspection according to conventional methods.

[0069] The actual feed rate of this grinding wheel is 1.5 mm; the feed rate is 30 mm / min. See the appendix. Figure 5 The cutting edge of the comparative grinding wheel tool has defects such as cracks and chipping, which damage the workpiece and cannot be used for grooving Ti(C,N)-based metal ceramic tools.

[0070] Comparative Example 2 involves the preparation of a resin-bonded diamond grinding wheel, using the following steps: (1) The modified polyimide resin powder and diamond abrasive are mixed at a volume ratio of 60% and 40%, respectively. After being thoroughly mixed, the mixture is passed through a 320-mesh sieve to obtain the grinding layer mixture. (2) Then the grinding layer mixture is evenly fed into the assembled mold and cold-pressed at 120 MPa; (3) Place the mold containing the grinding wheel blank into the flat vulcanizing machine, preheat it with a pressure of 20 MPa on the flat vulcanizing machine, then press it up to 80 MPa for hot pressing, raise the temperature from room temperature to 220°C in 10 minutes, keep it at the temperature for 15 minutes, raise the temperature to 320°C in 5 minutes, keep it at the temperature for 60 minutes, and then cool it naturally. The grinding wheel is obtained by demolding. (4) The diamond grinding wheel is obtained by machining and inspection according to conventional methods.

[0071] The actual feed rate of this grinding wheel is 1.0 mm and the feed speed is 30 mm / min, which is similar to the resin grinding wheels used in commercially available Ti(C,N) based cermet cutting tools; however, the grinding wheel will cause the tool body to turn black.

[0072] Comparative Example 3 involves the preparation of a composite-bonded diamond grinding wheel, using the following steps: (1) Mix the modified polyimide resin powder, metal mixed powder and diamond particles in a three-dimensional mixer at a volume percentage of 60%, 30% and 10% respectively for 1 hour, and then pass them through a 320-mesh sieve. The material that passes through the sieve is the grinding layer mixture. (2) Add the grinding layer mixture to the mold with the matrix, then place the mold in the flat vulcanizing machine, preheat it on the flat vulcanizing machine with a pressure of 20 MPa, then press it up to 80 MPa, raise the temperature from room temperature to 220°C in 10 minutes, keep it at the temperature for 15 minutes, raise the temperature to 320°C in 5 minutes, keep it at the temperature for 60 minutes, and then cool it naturally. The grinding wheel is obtained by demolding. (3) The composite diamond grinding wheel is obtained by machining and inspection according to conventional methods.

[0073] The actual feed rate of this grinding wheel is 2.0 mm, and the feed rate is 40 mm / min. See attached [reference]. Figure 6 The cutting edge chipping of the comparative grinding wheel tool is too large, which does not meet the quality requirements, makes it impossible to continue machining, and makes it impossible to verify the dressing interval and lifespan, making it unsuitable for machining Ti(C,N) based cermet tools.

[0074] Comparative Example 4 The metal mixture powder has the composition of Cu 47%, Sn 47%, Ag 5%, and graphite 1%. The metal mixture powder is cold-pressed at 100 MPa on a cold press, and then further processed in a 1×10⁻⁶ kJ / m³ process. -2 Sintering was carried out in a vacuum sintering furnace of Pa. The sintering temperature curve was as follows: the temperature was raised from room temperature to 300℃ in 0.5 h, held for 1 h, then raised to 600℃ in 0.5 h, held for 2 h, and then rapidly cooled in water to obtain a metal billet. The metal billet was crushed and placed in a planetary ball mill and ball-milled at 330 rpm for 3 h. After that, it was passed through a combination 60 and 80 mesh sieve, and the particles between the 60 and 80 mesh sieves were selected to obtain a metal mixed powder.

[0075] Next, referring to Comparative Example 3, a composite diamond grinding wheel was prepared. However, the problem of excessive chipping of the cutting edge of the tool still occurred after grooving.

[0076] Comparative Example 5 In addition to the preparation process, the formulation specified in this invention also benefits the performance of the grinding wheel.

[0077] Referring to Example 1, the metal mixed powder composition is Cu 45%, Sn 45%, Ag 5%, Ni 4%, and graphite 1%. The feed rate of the prepared grinding wheel in actual application is 1.2 mm, which is a small improvement compared to existing grinding wheels.

[0078] Referring to Example 1, 3% ammonium bicarbonate pore-forming agent (with the weight of modified polyimide resin powder and metal abrasive composite being 100%) was added to the grinding layer mixture. In actual application, the dressing interval of the prepared grinding wheel was 280 cycles, which was not significantly improved compared with existing grinding wheels.

[0079] Referring to Example 1, the metal mixed powder composition is Cu 52%, Sn 42%, Ag 5%, and graphite 1%. The feed rate of the prepared grinding wheel in actual application is 1.3 mm, which is not much of an improvement compared to existing grinding wheels.

[0080] Referring to Example 1, the metal mixed powder composition is Cu 47%, Sn 47%, Ag 6%, and the actual feed rate of the prepared grinding wheel is 33 mm / min, which is not significantly improved compared with existing grinding wheels.

[0081] Ceramic tools are widely used in aerospace cutting tools due to their good hardness, excellent wear resistance, and corrosion resistance. Titanium-based cermet tool materials have low thermal conductivity, high strength, and high chemical reactivity, making them typical difficult-to-machine materials. Long cutting times often lead to increased adhesive and diffusion wear during machining, resulting in frequent tool changes. Furthermore, the cutting process easily exacerbates chatter during finishing, severely impacting the surface integrity, roughness, and thickness tolerances of the tool. This results in low machining efficiency, failing to meet the requirements of high-performance machining and quality in major engineering applications. Currently, cermet tools prepared by grinding wheels suffer from bottlenecks such as low machining efficiency and poor surface quality. This invention discloses a diamond grinding wheel, specifically a resin-metal composite diamond grinding wheel for Ti(C,N)-based cermet cutting tools and its application. The volume percentages of the metal binder and diamond abrasive are 68-75% and 25-32%, respectively; the volume percentages of the resin powder and metal abrasive composite are 50-60% and 40-50%, respectively; the resin powder is a modified polyimide resin with a curing temperature of 350-400℃; the metal mixture powder is sintered from the following components in the following weight ratio: Cu 47%, Sn 47%, Ag 5%, and graphite 1%. When the diamond grinding wheel prepared using this method is used with Ti(C,N)-based cermet cutting tools on a five-axis CNC machine tool, the grinding wheel will not crack, and the grooved tool body will not exhibit defects such as blackening or edge chipping, nor will it damage the workpiece. It combines the advantages of machining quality, machining efficiency, and machining life, exhibiting extremely high grinding efficiency during machining; when machining Ti(C,N)-based cermet end mills, the overall machining efficiency is increased by 300-400%.

Claims

1. A composite diamond grinding wheel for Ti-based cermet cutting tools, comprising a grinding layer, characterized in that, The grinding layer comprises resin and a metal abrasive composite; the metal abrasive composite is obtained by sintering metal mixed powder and abrasive; the metal mixed powder comprises Cu, Sn, Ag, and carbon materials.

2. The composite diamond grinding wheel for Ti-based cermet cutting tools according to claim 1, characterized in that, The grinding layer is prepared by hot pressing of resin powder and metal abrasive composite.

3. The composite diamond grinding wheel for Ti-based cermet cutting tools according to claim 1, characterized in that, The resin powder is modified polyimide resin powder; the metal mixed powder is composed of copper powder, tin powder, silver powder, and graphite powder; the abrasive is diamond.

4. The method for preparing the composite diamond grinding wheel for Ti-based cermet cutting tools according to claim 1, characterized in that, Includes the following steps: (1) The metal mixture powder and abrasive are mixed and sintered, and then the sintered blank is crushed to obtain a metal abrasive composite. (2) The resin powder and the metal abrasive composite are mixed and hot-pressed to obtain a composite diamond grinding wheel for Ti-based metal ceramic cutting tools.

5. The method for preparing the composite diamond grinding wheel for Ti-based cermet cutting tools according to claim 4, characterized in that, The sintering temperature profile is as follows: 0.1–1 h from room temperature to 250–350 °C, hold for 0.5–1.5 h, then 0.1–1 h to 500–600 °C, hold for 1–2 h; the hot pressing pressure is 20–80 MPa; the hot pressing temperature profile is as follows: 5–10 minutes from room temperature to 200–250 °C, hold for 10–20 minutes, then 5–10 minutes to 320–350 °C, hold for 40–60 minutes.

6. The method for preparing the composite diamond grinding wheel for Ti-based cermet cutting tools according to claim 4, characterized in that, The volume ratio of metal mixed powder to abrasive is (68-75):(25-32); the volume ratio of resin powder to metal abrasive composite is (50-60):(40-50).

7. The method for preparing the Ti(C,N)-based cermet tool composite diamond grinding wheel according to claim 4, characterized in that, The metal mixed powder is composed of copper powder, tin powder, silver powder and graphite powder; the weight ratio of copper powder, tin powder, silver powder and graphite powder is (45~50): (45~50): (2~8): (0.5~1.5).

8. The application of the composite diamond grinding wheel for Ti-based cermet cutting tools as described in claim 1 in the machining of Ti-based cermets.

9. The application according to claim 8, characterized in that, The processing involves grooving.

10. A method for machining Ti-based cermet cutting tools, characterized in that, Grooving is achieved using the composite diamond grinding wheel for Ti-based cermet tools as described in claim 1, thereby realizing the machining of Ti-based cermet tools.

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