Hard alloy cutter and preparation method thereof

Abstract

The invention relates to the technical field of hard alloy cutters, in particular to a hard alloy cutter and a preparation method thereof. Comprising the following raw materials: 60-70 parts of WC powder, 8-12 parts of Ni powder, 5-8 parts of Mo2C powder, 2-4 parts of Si3N4 powder, 6-10 parts of a strengthening phase and 4-8 parts of an improved additive. Comprising the following steps: S1, weighing raw materials; s2, mixing and stirring WC powder, Ni powder, Mo2C powder and Si3N4 powder, performing ball milling, drying, performing compression molding in a mold to obtain a green body, putting the green body into a tubular furnace, performing sintering treatment under nitrogen, and performing grinding and sieving to obtain an intermediate product; and S3, the intermediate product, a strengthening phase and an improved additive are mixed, stirred and dried, compression molding is conducted in a mold, microwave sintering is conducted under argon, and the hard alloy cutter is obtained. The prepared hard alloy cutter has excellent toughness and wear resistance, meanwhile, the high strength characteristic can be effectively kept, and the service life of the alloy cutter is remarkably prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of cemented carbide cutting tools, and particularly relates to a cemented carbide cutting tool and a preparation method thereof. Background Art

[0002] In modern manufacturing, cemented carbide cutting tools have become key tools in the field of metal cutting due to their excellent hardness, wear resistance, and thermal stability. However, with the development of manufacturing towards high precision, high efficiency, and high reliability, existing cemented carbide cutting tools face numerous challenges. On the one hand, in the face of the widespread application of new high-strength and high-hardness materials (such as nickel-based superalloys and ultra-high-strength steels), the wear resistance and impact toughness of traditional cemented carbide cutting tools are insufficient. During the cutting process, problems such as increased tool wear and edge chipping are prone to occur, resulting in a decline in machining accuracy and a significant shortening of tool life. For example, when machining nickel-based superalloys in the aerospace field, the durability of traditional tools is extremely low, and frequent tool changes seriously affect production efficiency and cost. On the other hand, the current preparation process has limitations. Conventional powder metallurgy methods are difficult to ensure uniform distribution of alloy components, easily causing internal tissue defects and reducing the comprehensive performance of the tools. Therefore, it is urgent to develop a cemented carbide cutting tool with excellent performance and an advanced preparation process. Summary of the Invention

[0003] To solve the above problems, the present invention proposes a cemented carbide cutting tool and a preparation method thereof.

[0004] The present invention provides a cemented carbide cutting tool, including the following raw materials in parts by mass: 60 - 70 parts of WC powder, 8 - 12 parts of Ni powder, Mo 2 5 - 8 parts of C powder, Si 3 N 4 2 - 4 parts of powder, 6 - 10 parts of strengthening phase, 4 - 8 parts of improved additive.

[0005] Preferably, the strengthening phase is prepared by the following method: Disperse cobalt nitrate and yttrium nitrate in deionized water, stir for 10 - 15 min, add a complexing agent, heat and stir for 30 - 45 min, add citric acid, heat to 80 - 100 °C, stir for 5 - 7 h, dry, perform heat treatment, naturally cool, grind and screen to obtain the strengthening phase.

[0006] Preferably, the strengthening phase includes the following components in parts by mass: 20 - 30 parts of cobalt nitrate, 8 - 12 parts of yttrium nitrate, 1 - 3 parts of complexing agent, 10 - 15 parts of citric acid, 70 - 80 parts of deionized water.

[0007] Preferably, the complexing agent is prepared by the following method: A1. Disperse tartaric acid in dichloromethane, stir, then add copper sulfate and p-toluenesulfonyl chloride, stir, control the temperature at 4 - 8 °C, stir for 4 - 6 h, heat and stir, centrifuge, and vacuum dry to obtain sulfonylated tartaric acid; A2. Disperse the sulfonylated tartaric acid in deionized water, add graphene oxide and 1-ethyl-(3-dimethylaminopropyl)carbodiimide (EDC), ultrasonically disperse, adjust the pH, heat and stir for 4 - 6 h, filter, and freeze dry to obtain the complexing agent.

[0008] Preferably, in step A1, the components include the following parts by mass: 8 - 12 parts of tartaric acid, 15 - 20 parts of p-toluenesulfonyl chloride, 0.2 - 0.5 parts of copper sulfate, and 70 - 80 parts of dichloromethane; in step A2, the components include the following parts by mass: 5 - 10 parts of sulfonylated tartaric acid, 2 - 4 parts of graphene oxide, 60 - 70 parts of deionized water, and 0.1 - 0.2 parts of 1-ethyl-(3-dimethylaminopropyl)carbodiimide.

[0009] Preferably, the improved additive is prepared by the following method: B1. Add chromium formate and aluminum nitrate to deionized water, stir, add ferric nitrate, stir, and then add boric acid, adjust the pH to 3 - 4 to obtain a mixed salt solution; B2. Disperse sodium alginate in deionized water, heat and stir, add calcium chloride, stir to obtain a sol; B3. Add the sol to the mixed salt solution, stir, freeze dry, pre-calcine to obtain a composite oxide; perform microwave sintering on the composite oxide to obtain an intermediate, add the intermediate to the etching solution, soak for 5 - 7 min, dry, grind and sieve to obtain the improved additive.

[0010] Preferably, in step B1, the components include the following parts by mass: 3 - 6 parts of chromium formate, 5 - 8 parts of aluminum nitrate, 15 - 20 parts of ferric nitrate, 0.5 - 1 part of boric acid, and 120 - 150 parts of deionized water; in step B2, the components include the following parts by mass: 2 - 4 parts of sodium alginate, 4 - 6 parts of calcium chloride, and 60 - 70 parts of deionized water; in step B3, the mass ratio of the sol to the mixed salt solution is 30 - 45:60 - 70; the mass ratio of the intermediate to the etching solution is 15 - 18:25 - 30.

[0011] The present invention also provides a preparation method of a cemented carbide cutting tool, including the following steps: S1. Weigh the raw materials in the above parts by mass; S2. WC powder, Ni powder, Mo 2 C powder and Si 3 N 4Mix and stir the powder for 20 - 30 min, ball mill, dry, press and form in a mold to obtain a green body. Place the green body in a tube furnace and sinter it under nitrogen, then grind and screen to obtain an intermediate product; S3. Mix and stir the intermediate product with a strengthening phase and an improvement additive, dry, press and form in a mold, and perform microwave sintering under argon to obtain a cemented carbide cutting tool.

[0012] Preferably, the sintering treatment in step S2 includes: heating at a heating rate of 8 - 15 °C / min to 500 - 700 °C and holding for 45 - 70 min; then heating at a heating rate of 5 - 8 °C / min to 800 - 900 °C and holding for 2 - 3 h; then heating at a heating rate of 3 - 5 °C / min to 1000 - 1100 °C and holding for 1 - 2 h.

[0013] Preferably, the microwave sintering in step S3 includes: heating at a heating rate of 50 - 80 °C / min to 800 - 900 °C and holding for 30 - 45 min, controlling the microwave power to be 3 - 6 KW and the frequency to be 2.45 GHz; heating at a heating rate of 10 - 20 °C / min to 1350 - 1400 °C and holding for 40 - 60 min, controlling the microwave power to be 1 - 2 KW and the frequency to be 2.45 GHz.

[0014] The present invention has the following beneficial effects: The present invention first prepares a sulfonylated tartaric acid derivative through the condensation reaction of tartaric acid and p-toluenesulfonyl chloride; covalently couples this derivative with graphene oxide under the action of 1-ethyl-(3-dimethylaminopropyl)carbodiimide to obtain a complexing agent. The hydroxyl and epoxy groups on the surface of graphene oxide and the sulfonic acid groups introduced by sulfonylated tartaric acid produce a synergistic effect to form complexing sites with a three-dimensional network structure, significantly enhancing the complexing ability for metal ions; at the same time, the lamellar structure of graphene plays a bridging and supporting role during the crack propagation process of the material, effectively inhibiting the further extension of cracks; in the stage of preparing the strengthening phase, first carry out a coordination reaction between cobalt nitrate, yttrium nitrate and the complexing agent, introduce citric acid as an auxiliary ligand, and form a strengthening phase by regulating the coordination environment. The carboxyl group of citric acid forms a more stable polynuclear complex with metal ions, and at the same time the hydroxyl group of citric acid and the groups of the complexing agent form a three-dimensional network structure, promoting the uniform dispersion of metal ions. Among them, the addition of cobalt elements can significantly enhance the toughness and wear resistance of the cemented carbide, and yttrium elements effectively improve the hardness and wear resistance of the material by refining the alloy grains. The synergistic effect of the two enables the cemented carbide to obtain more excellent wear resistance, thereby extending the service life of the cutting tool. In addition, the co-introduction of zirconium and yttrium elements can optimize the microscopic structure of the alloy and relieve the internal stress concentration problem through the stress relaxation mechanism, further improving the toughness performance of the material.

[0015] The present invention mixes chromium formate, aluminum nitrate, iron nitrate and boric acid to obtain a mixed salt solution; subsequently, this solution is mixed with sodium alginate and calcium chloride, and the gel formed by the reaction of sodium alginate and calcium chloride produces a templating effect, enabling Cr 3+ 、Al 3 + 、Fe 3+ to achieve uniform dispersion at the molecular scale; after pre-calcination treatment, the components react to form a composite oxide, significantly enhancing the synergy between the components. Among them, boric acid is converted into a boride under high-temperature conditions. On the one hand, it fills the grain boundaries and inhibits grain migration, and on the other hand, it can reduce the temperature of the subsequent sintering process. Through freeze-drying and etching processes, the material forms a porous structure, which can enhance the interfacial wettability of the cemented carbide, promote element diffusion, thereby reducing porosity and improving the material density and interfacial bonding strength. Using microwave sintering technology for the composite oxide can further refine the grains, increase the grain boundary density, and improve the material strength. The introduction of Cr and Al elements forms a corrosion-resistant phase, and Fe and B elements form a hard phase. The combined action of the two can effectively resist wear and chemical corrosion during the friction process, ultimately extending the service life of the cemented carbide.

[0016] The present invention now high-speed stirs and mixes WC powder, Ni powder, Mo 2 C powder and Si 3 N 4 powder, sinters under nitrogen, grinds and sieves, and then high-speed stirs and mixes with the strengthening phase and the improvement additive, and microwaves sinter under argon, finally obtaining a cemented carbide tool; in the low-temperature stage, the moisture and residual organic matter in the raw materials can be removed, avoiding the generation of pores in the later stage of sintering; in the medium-temperature stage, it promotes the preliminary melting of Ni powder and wets the WC particles, forming local liquid-phase diffusion and preliminarily connecting the skeleton; in the high-temperature stage, MoC is dissolved in the Ni binder phase or the WC lattice to form a solid-solution strengthening phase, and at the same time, Si 3 N 4 particles are uniformly dispersed, inhibiting the excessive coarsening of WC grains; microwave heating directly generates heat using the dielectric loss of the material, with a fast heating rate and a short holding time in the high-temperature section, which can inhibit the abnormal growth of WC grains, and at the same time promote the uniform penetration of the Ni binder phase into the WC grain boundaries, forming a finer two-phase structure; the obtained cemented carbide tool has a high density, fine grains, and a greatly improved mechanical strength; the total time of the two sinterings is lower than that of traditional single-stage sintering, especially the rapid heating and holding in the microwave section, which is suitable for industrial batch production. Specific Embodiments

[0017] The principles and features of the present invention are described below in conjunction with embodiments. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0018] WC powder, purchased from Shandong Xinbaiyi Metal Materials Co., Ltd., with a particle size of 2 - 3 μm; Ni powder, purchased from Shanghai Yingfeng Ruihuang Metal Materials Co., Ltd., with a particle size of 0.5 - 1 μm; Mo 2 C powder, purchased from Nangong Xingjiu New Material Technology Co., Ltd., with a particle size of 0.5 - 2 μm and an active ingredient of 99.9%; Si 3 N 4 powder, purchased from Ningbo Luofei Nano Technology Co., Ltd., with a particle size of 0.5 - 1.5 μm; graphene oxide, purchased from Jiangxi Shuobang New Material Technology Co., Ltd., with a particle size of 2 - 3 nm.

[0019] Example 1 A cemented carbide cutting tool, comprising raw materials in the following parts by mass: 60 parts of WC powder, 8 parts of Ni powder, Mo 2 5 parts of C powder, Si 3 N 4 2 parts of powder, 6 parts of strengthening phase, 4 parts of improved additive.

[0020] Among them, the strengthening phase is prepared by the following method: Disperse cobalt nitrate and yttrium nitrate in deionized water, stir at 200 rpm for 10 min, add a complexing agent, heat to 60 °C, stir at 100 rpm for 30 min, add citric acid, heat to 80 °C, stir at 150 rpm for 5 h, dry at 100 °C for 12 h, then perform heat treatment, heat at 2 °C / min to 300 °C, hold for 2 h, then heat at 5 °C / min to 600 °C, hold for 3 h, cool naturally, grind, and pass through a 1000 - mesh sieve to obtain the strengthening phase; by mass, among them, 20 parts of cobalt nitrate, 8 parts of yttrium nitrate, 70 parts of deionized water, 1 part of complexing agent, and 10 parts of citric acid.

[0021] Among them, the complexing agent is prepared by the following method: A1. Disperse tartaric acid in dichloromethane, stir at 100 rpm for 15 min, add copper sulfate and p - toluenesulfonyl chloride, stir for 3 min, control the temperature at 4 °C, stir at 150 rpm for 4 h, then heat to 25 °C, stir at 80 rpm for 10 h, centrifuge at 3000 rpm for 5 min, and vacuum dry at 60 °C for 12 h to obtain sulfonated tartaric acid; by mass, among them, 15 parts of tartaric acid, 8 parts of p - toluenesulfonyl chloride, 0.2 part of copper sulfate, and 70 parts of dichloromethane; A2. Disperse sulfonated tartaric acid in deionized water, add graphene oxide and 1-ethyl-(3-dimethylaminopropyl)carbodiimide, ultrasonically disperse at 30 KHz for 25 min, adjust the pH to 5.5, heat to 60 °C, stir at 100 rpm for 4 h, filter, and freeze-dry at -50 °C for 12 h to obtain a complexing agent; by mass, 5 parts of sulfonated tartaric acid, 2 parts of graphene oxide, 60 parts of deionized water, and 0.1 part of 1-ethyl-(3-dimethylaminopropyl)carbodiimide.

[0022] Among them, the improved additive is prepared by the following method: B1. Add chromium formate and aluminum nitrate to deionized water, stir at 100 rpm for 10 min, add iron nitrate, stir at 100 rpm for 15 min, then add boric acid, and adjust the pH to 3 to obtain a mixed salt solution; by mass, 3 parts of chromium formate, 5 parts of aluminum nitrate, 15 parts of iron nitrate, 0.5 part of boric acid, and 120 parts of deionized water; B2. Disperse sodium alginate in deionized water, heat to 30 °C, stir at 80 rpm for 8 min, add calcium chloride, and stir for 5 min to obtain a sol; by mass, 2 parts of sodium alginate, 4 parts of calcium chloride, and 60 parts of deionized water; B3. Add the sol to the mixed salt solution, stir at 100 rpm for 20 min, freeze-dry at -50 °C for 24 h, pre-calcine, heat at a heating rate of 8 °C / min to 300 °C, hold for 2 h, then heat at a heating rate of 5 °C / min to 700 °C, hold for 1 h; cool to room temperature to obtain a composite oxide; perform microwave sintering on the composite oxide, heat at a heating rate of 10 °C / min, microwave sinter at 2.45 GHz and 1200 °C for 30 min, control the microwave power to 1.5 KW, cool to room temperature to obtain an intermediate, add the intermediate to the etching solution, soak for 5 min, dry at 80 °C for 4 h, grind through a 3000-mesh sieve to obtain the improved additive; among them, the mass ratio of the sol to the mixed salt solution is 30:60; the mass ratio of the intermediate to the etching solution is 15:25; the etching solution is prepared by mixing nitric acid and hydrofluoric acid with a mass ratio of 3:0.4.

[0023] A preparation method of a cemented carbide cutting tool includes the following steps: S1. Weigh the raw materials of the said mass parts; S2. WC powder, Ni powder, Mo 2 C powder and Si 3 N 4Mix the powders, stir at 300 rpm for 20 min, ball mill at 200 rpm for 16 h, control the mass ratio of balls to materials to liquid to be 10:2:1, select zirconia balls, select absolute ethanol as the dispersion medium, dry at 70 °C for 3 h, press into a mold, control the molding pressure to be 10 MPa to obtain a green body. Place the green body in a tube furnace and conduct sintering treatment under nitrogen. With a heating rate of 8 °C / min, heat up to 500 °C and hold for 45 min; then with a heating rate of 5 °C / min, heat up to 800 °C and hold for 2 h; then with a heating rate of 3 °C / min, heat up to 1000 °C and hold for 1 h, and then cool down to room temperature at 2 °C / min, grind through a 3000-mesh sieve to obtain an intermediate product; S3. Mix the intermediate product with the strengthening phase and the improved additive, stir at 600 rpm for 15 min, dry at 70 °C for 3 h, press into a mold, control the molding pressure to be 10 MPa, conduct microwave sintering under argon. With a heating rate of 50 °C / min, heat up to 800 °C and hold for 30 min, control the microwave power to be 3 KW and the frequency to be 2.45 GHz; with a heating rate of 10 °C / min, heat up to 1350 °C and hold for 40 min, control the microwave power to be 1 KW and the frequency to be 2.45 GHz, and cool with the furnace to obtain a cemented carbide cutting tool.

[0024] Example 2 A cemented carbide cutting tool, comprising raw materials in the following mass parts: 70 parts of WC powder, 12 parts of Ni powder, Mo 2 8 parts of C powder, Si 3 N 4 4 parts of powder, 10 parts of strengthening phase, 8 parts of improved additive.

[0025] Among them, the strengthening phase is prepared by the following method: Disperse cobalt nitrate and yttrium nitrate in deionized water, stir at 300 rpm for 15 min, add a complexing agent, heat to 70 °C, stir at 200 rpm for 45 min, add citric acid, heat to 100 °C, stir at 200 rpm for 7 h, dry at 110 °C for 20 h, and then conduct heat treatment. With a heating rate of 4 °C / min, heat up to 400 °C and hold for 3 h, then with a heating rate of 10 °C / min, heat up to 700 °C and hold for 5 h, cool naturally, grind, and pass through a 1000-mesh sieve to obtain the strengthening phase; by mass parts, 30 parts of cobalt nitrate, 12 parts of yttrium nitrate, 80 parts of deionized water, 3 parts of complexing agent, and 15 parts of citric acid.

[0026] Among them, the complexing agent is prepared by the following method: A1. Disperse tartaric acid in dichloromethane, stir at 200 rpm for 20 min, add copper sulfate and p-toluenesulfonyl chloride, stir for 5 min, control the temperature at 8 °C, stir at 200 rpm for 6 h, then raise the temperature to 30 °C, stir at 120 rpm for 12 h, centrifuge at 5000 rpm for 8 min, and vacuum dry at 70 °C for 16 h to obtain sulfonylated tartaric acid; by mass, 20 parts of tartaric acid, 12 parts of p-toluenesulfonyl chloride, 0.5 part of copper sulfate, and 80 parts of dichloromethane; A2. Disperse the sulfonylated tartaric acid in deionized water, add graphene oxide and 1-ethyl-(3-dimethylaminopropyl)carbodiimide, ultrasonically disperse at 40 KHz for 35 min, adjust the pH to 6.5, heat to 70 °C, stir at 200 rpm for 6 h, filter, and freeze-dry at -50 °C for 18 h to obtain the complexing agent; by mass, 10 parts of sulfonylated tartaric acid, 4 parts of graphene oxide, 70 parts of deionized water, and 0.2 part of 1-ethyl-(3-dimethylaminopropyl)carbodiimide.

[0027] Among them, the improved additive is prepared by the following method: B1. Add chromium formate and aluminum nitrate to deionized water, stir at 150 rpm for 15 min, add iron nitrate, stir at 200 rpm for 20 min, then add boric acid, and adjust the pH to 4 to obtain a mixed salt solution; by mass, 6 parts of chromium formate, 8 parts of aluminum nitrate, 20 parts of iron nitrate, 1 part of boric acid, and 150 parts of deionized water; B2. Disperse sodium alginate in deionized water, heat to 40 °C, stir at 100 rpm for 10 min, add calcium chloride, and stir for 8 min to obtain a sol; by mass, 4 parts of sodium alginate, 6 parts of calcium chloride, and 70 parts of deionized water; B3. Add the sol to the mixed salt solution, stir at 200 rpm for 30 min, freeze-dry at -50 °C for 36 h, pre-calcine, raise the temperature at a heating rate of 12 °C / min to 400 °C, hold for 3 h, then raise the temperature at a heating rate of 8 °C / min to 800 °C, hold for 2 h; cool to room temperature to obtain a composite oxide; perform microwave sintering on the composite oxide, raise the temperature at a heating rate of 15 °C / min, microwave sinter at 2.45 GHz and 1200 °C for 45 min, control the microwave power at 1.5 KW, cool to room temperature to obtain an intermediate, add the intermediate to the etching solution, soak for 7 min, dry at 100 °C for 6 h, and grind through a 3000-mesh sieve to obtain the improved additive; among them, the mass ratio of the sol to the mixed salt solution is 45:70; the mass ratio of the intermediate to the etching solution is 18:30; the etching solution is prepared by mixing nitric acid and hydrofluoric acid with a mass ratio of 4:0.5.

[0028] A preparation method of a cemented carbide cutting tool includes the following steps: S1. Weigh the raw materials in the stated parts by mass; S2. Mix WC powder, Ni powder, Mo 2 C powder and Si 3 N 4 powder, stir at 400 rpm for 30 min, ball mill at 300 rpm for 16 h, control the mass ratio of ball to material to liquid to be 10:2:1, select zirconia balls, select anhydrous ethanol as the dispersion medium, dry at 80 °C for 5 h, press into a mold, control the molding pressure to be 15 MPa to obtain a green body, place the green body in a tube furnace, carry out sintering treatment under nitrogen, with a heating rate of 15 °C / min, heat up to 700 °C, hold for 70 min; then with a heating rate of 8 °C / min, heat up to 900 °C, hold for 3 h; then with a heating rate of 5 °C / min, heat up to 1100 °C, hold for 2 h, then cool down to room temperature at 3 °C / min, grind through a 3000-mesh sieve to obtain an intermediate product; S3. Mix the intermediate product with the strengthening phase and the improvement additive, stir at 800 rpm for 20 min, dry at 80 °C for 5 h, press into a mold, control the molding pressure to be 15 MPa, carry out microwave sintering under argon, with a heating rate of 80 °C / min, heat up to 900 °C, hold for 45 min, control the microwave power to be 6 KW and the frequency to be 2.45 GHz; with a heating rate of 20 °C / min, heat up to 1400 °C, hold for 60 min, control the microwave power to be 2 KW and the frequency to be 2.45 GHz, cool with the furnace to obtain a cemented carbide cutting tool.

[0029] Example 3 A cemented carbide cutting tool comprises the following raw materials in parts by mass: 65 parts of WC powder, 10 parts of Ni powder, Mo 2 7 parts of C powder, Si 3 N 4 3 parts of powder, 8 parts of strengthening phase, 6 parts of improvement additive.

[0030] Among them, the strengthening phase is prepared by the following method: Disperse cobalt nitrate and yttrium nitrate in deionized water, stir at 260 rpm for 12 min, add a complexing agent, heat to 65 °C, stir at 150 rpm for 40 min, add citric acid, heat to 90 °C, stir at 180 rpm for 6 h, dry at 105 °C for 16 h, then carry out heat treatment, with a heating rate of 3 °C / min, heat up to 350 °C, hold for 2.5 h, then with a heating rate of 8 °C / min, heat up to 650 °C, hold for 4 h, cool naturally, grind, pass through a 1000-mesh sieve to obtain the strengthening phase; by mass, 25 parts of cobalt nitrate, 10 parts of yttrium nitrate, 75 parts of deionized water, 2 parts of complexing agent, 12 parts of citric acid.

[0031] Among them, the complexing agent is prepared by the following method: A1. Disperse tartaric acid in dichloromethane, stir at 150 rpm for 18 min, add copper sulfate and p-toluenesulfonyl chloride, stir for 4 min, control the temperature at 6 °C, stir at 180 rpm for 5 h, then raise the temperature to 28 °C, stir at 100 rpm for 11 h, centrifuge at 4000 rpm for 7 min, and vacuum dry at 65 °C for 14 h to obtain sulfonylated tartaric acid; by mass, 18 parts of tartaric acid, 10 parts of p-toluenesulfonyl chloride, 0.4 part of copper sulfate, and 75 parts of dichloromethane; A2. Disperse sulfonylated tartaric acid in deionized water, add graphene oxide and 1-ethyl-(3-dimethylaminopropyl)carbodiimide, ultrasonically disperse at 35 kHz for 30 min, adjust the pH to 6, heat to 65 °C, stir at 150 rpm for 5 h, filter, and freeze-dry at -50 °C for 16 h to obtain the complexing agent; by mass, 8 parts of sulfonylated tartaric acid, 3 parts of graphene oxide, 65 parts of deionized water, and 0.15 part of 1-ethyl-(3-dimethylaminopropyl)carbodiimide.

[0032] Among them, the improved additive is prepared by the following method: B1. Add chromium formate and aluminum nitrate to deionized water, stir at 120 rpm for 13 min, add iron nitrate, stir at 150 rpm for 18 min, then add boric acid, and adjust the pH to 3.5 to obtain a mixed salt solution; by mass, 5 parts of chromium formate, 7 parts of aluminum nitrate, 17 parts of iron nitrate, 0.8 part of boric acid, and 140 parts of deionized water; B2. Disperse sodium alginate in deionized water, heat to 35 °C, stir at 90 rpm for 9 min, add calcium chloride, and stir for 7 min to obtain a sol; by mass, 3 parts of sodium alginate, 5 parts of calcium chloride, and 65 parts of deionized water; B3. Add the sol to the mixed salt solution, stir at 150 rpm for 25 min, freeze-dry at -50 °C for 30 h, pre-calcine, raise the temperature at a heating rate of 10 °C / min to 350 °C, hold for 2.5 h, then raise the temperature at a heating rate of 7 °C / min to 750 °C, hold for 1.5 h; cool to room temperature to obtain a composite oxide; perform microwave sintering on the composite oxide, raise the temperature at a heating rate of 13 °C / min, microwave sinter at 2.45 GHz and 1200 °C for 40 min, control the microwave power at 1.5 KW, cool to room temperature to obtain an intermediate, add the intermediate to the etching solution, soak for 6 min, dry at 9 °C for 5 h, grind through a 3000-mesh sieve to obtain the improved additive; among them, the mass ratio of the sol to the mixed salt solution is 40:65; the mass ratio of the intermediate to the etching solution is 17:28; the etching solution is prepared by mixing nitric acid and hydrofluoric acid with a mass ratio of 3.5:0.45.

[0033] A preparation method of a cemented carbide cutting tool, comprising the following steps: S1. Weigh the raw materials in the said parts by mass; S2. Mix WC powder, Ni powder, Mo 2 C powder and Si 3 N 4 powder, stir at 350 rpm for 25 min, ball mill at 260 rpm for 16 h, control the mass ratio of ball to material to liquid to be 10:2:1, select zirconia balls, select absolute ethanol as the dispersion medium, dry at 75 °C for 4 h, press into a mold, control the molding pressure to be 12 MPa to obtain a green body, place the green body in a tubular furnace, perform sintering treatment under nitrogen, with a heating rate of 12 °C / min, heat up to 600 °C, hold for 60 min; then with a heating rate of 7 °C / min, heat up to 850 °C, hold for 2.5 h; then with a heating rate of 4 °C / min, heat up to 1050 °C, hold for 1.5 h, then cool down to room temperature at 3 °C / min, grind through a 3000-mesh sieve to obtain an intermediate product; S3. Mix the intermediate product with a strengthening phase and an improvement additive, stir at 700 rpm for 18 min, dry at 75 °C for 4 h, press into a mold, control the molding pressure to be 12 MPa, perform microwave sintering under argon, with a heating rate of 70 °C / min, heat up to 850 °C, hold for 40 min, control the microwave power to be 4 KW and the frequency to be 2.45 GHz; with a heating rate of 15 °C / min, heat up to 1380 °C, hold for 50 min, control the microwave power to be 1.5 KW and the frequency to be 2.45 GHz, cool down with the furnace to obtain the cemented carbide cutting tool.

[0034] Comparative Example 1 Comparative Example 1 is the same as Example 1, the only difference being that the preparation method of the complexing agent is different, specifically as follows: The complexing agent is prepared by the following method: Disperse tartaric acid in deionized water, add graphene oxide and 1-ethyl-(3-dimethylaminopropyl)carbodiimide, ultrasonically disperse at 30 KHz for 25 min, adjust the pH to 5.5, heat to 60 °C, stir at 100 rpm for 4 h, filter, freeze-dry at -50 °C for 12 h to obtain the complexing agent; by mass, 5 parts of tartaric acid, 2 parts of graphene oxide, 60 parts of deionized water, and 0.1 part of 1-ethyl-(3-dimethylaminopropyl)carbodiimide.

[0035] Comparative Example 2 Comparative Example 2 is the same as Example 1, the only difference being that the preparation method of the strengthening phase is different, specifically as follows: The strengthening phase is prepared by the following method: Disperse cobalt nitrate and yttrium nitrate in deionized water, stir at 200 rpm for 10 min, add a complexing agent, heat to 80 °C, stir at 150 rpm for 5 h, dry at 100 °C for 12 h, then conduct heat treatment, heat at a rate of 2 °C / min to 300 °C, hold for 2 h, then heat at a rate of 5 °C / min to 600 °C, hold for 3 h, cool naturally, grind, and pass through a 1000-mesh sieve to obtain the strengthening phase; by mass, 20 parts of cobalt nitrate, 8 parts of yttrium nitrate, 70 parts of deionized water, and 11 parts of complexing agent.

[0036] Comparative Example 3 Comparative Example 3 is the same as Example 1, the only difference being that the preparation method of the improved additive is different, specifically as follows: The improved additive is prepared by the following method: B1. Add chromium formate and aluminum nitrate to deionized water, stir at 100 rpm for 10 min, add iron nitrate, stir at 100 rpm for 15 min, then add boric acid, and adjust the pH to 3 to obtain a mixed salt solution; by mass, 3 parts of chromium formate, 5 parts of aluminum nitrate, 15 parts of iron nitrate, 0.5 part of boric acid, and 120 parts of deionized water; B2. Disperse sodium alginate in deionized water, heat to 30 °C, stir at 80 rpm for 8 min, add calcium chloride, and stir for 5 min to obtain a sol; by mass, 2 parts of sodium alginate, 4 parts of calcium chloride, and 60 parts of deionized water; B3. Add the sol to the mixed salt solution, stir at 100 rpm for 20 min, freeze-dry at -50 °C for 24 h, pre-calcine, heat at a heating rate of 8 °C / min to 300 °C, hold for 2 h, then heat at a heating rate of 5 °C / min to 700 °C, hold for 1 h; cool to room temperature to obtain a composite oxide; conduct microwave sintering on the composite oxide, heat at a heating rate of 10 °C / min, microwave sinter at 2.45 GHz and 1200 °C for 30 min, control the microwave power to 1.5 KW, cool to room temperature, grind and pass through a 3000-mesh sieve to obtain the improved additive; among them, the mass ratio of the sol to the mixed salt solution is 30:60.

[0037] Comparative Example 4 Comparative Example 4 is the same as Example 1, the only difference being that the preparation method of the improved additive is different, specifically as follows: The improved additive is prepared by the following method: B1. Add chromium formate and aluminum nitrate to deionized water, stir at 100 rpm for 10 min, add iron nitrate, stir at 100 rpm for 15 min, then add boric acid, and adjust the pH to 3 to obtain a mixed salt solution; by mass, 3 parts of chromium formate, 5 parts of aluminum nitrate, 15 parts of iron nitrate, 0.5 part of boric acid, and 120 parts of deionized water; B2. Disperse sodium alginate in deionized water, heat to 30 °C, stir at 80 rpm for 8 min, add calcium chloride, and stir for 5 min to obtain a sol; by mass, 2 parts of sodium alginate, 4 parts of calcium chloride, and 60 parts of deionized water; B3. Add the sol to the mixed salt solution, stir at 100 rpm for 20 min, freeze-dry at -50 °C for 24 h, heat at a heating rate of 8 °C / min to 300 °C, hold for 2 h, then heat at a heating rate of 5 °C / min to 700 °C, hold for 1 h; then heat at a heating rate of 5 °C / min to 1200 °C, hold for 30 min, cool to room temperature to obtain an intermediate. Add the intermediate to the etching solution, soak for 5 min, dry at 80 °C for 4 h, and grind through a 3000-mesh sieve to obtain an improved additive; among them, the mass ratio of the sol to the mixed salt solution is 30:60; the mass ratio of the intermediate to the etching solution is 15:25; the etching solution is prepared by mixing nitric acid and hydrofluoric acid with a mass ratio of 3:0.4.

[0038] Comparative Example 5 Comparative Example 5 is the same as Example 1, except that the preparation method of the cemented carbide tool is different. Specifically: A preparation method of a cemented carbide tool includes the following steps: S1. Weigh the raw materials in the said mass parts; S2. Mix WC powder, Ni powder, Mo 2 C powder and Si 3 N 4 powder, stir at 300 rpm for 20 min, ball mill at 200 rpm for 16 h, control the mass ratio of balls to materials to liquid to be 10:2:1, select zirconia balls, select anhydrous ethanol as the dispersion medium, dry at 70 °C for 3 h, press into shape in a mold, control the molding pressure to be 10 MPa to obtain a green body. Place the green body in a tube furnace and conduct sintering treatment under nitrogen. Heat at a heating rate of 8 °C / min to 500 °C, hold for 45 min; then heat at a heating rate of 5 °C / min to 800 °C, hold for 2 h; then heat at a heating rate of 3 °C / min to 1000 °C, hold for 1 h, and then cool to room temperature at 2 °C / min, grind through a 3000-mesh sieve to obtain an intermediate product; S3. Mix the intermediate product with the strengthening phase and the improved additive, stir at 600 rpm for 15 min, dry at 70 °C for 3 h, press into shape in a mold, control the molding pressure to be 10 MPa, and conduct sintering treatment under argon. Heat at a heating rate of 8 °C / min to 500 °C, hold for 60 min; heat at a heating rate of 5 °C / min to 800 °C, hold for 30 min; then heat at a heating rate of 3 °C / min to 1350 °C, hold for 40 min, and cool with the furnace to obtain the cemented carbide tool.

[0039] Comparative Example 6 Comparative Example 6 is the same as Example 1, except that the preparation method of the cemented carbide tool is different. Specifically: A preparation method of a cemented carbide tool includes the following steps: S1. Weigh the raw materials in the said parts by mass; S2. Mix WC powder, Ni powder, Mo 2 C powder, Si 3 N 4 powder, reinforcing phase and improving additive, stir at 300 rpm for 20 min, ball mill at 200 rpm for 16 h, control the mass ratio of ball to material to liquid to be 10:2:1, select zirconia balls, select anhydrous ethanol as the dispersion medium, dry at 70 °C for 3 h, press and form in a mold, control the forming pressure to be 10 MPa to obtain a green body, place the green body in a tubular furnace, perform sintering treatment under nitrogen, increase the temperature to 500 °C at a heating rate of 8 °C / min, hold for 45 min; then increase the temperature to 800 °C at a heating rate of 5 °C / min, hold for 2 h; then increase the temperature to 1350 °C at a heating rate of 3 °C / min, hold for 1 h, and then decrease to room temperature at 2 °C / min to obtain the cemented carbide tool.

[0040] Performance Test Perform the following performance tests on the cemented carbide tools prepared in Examples 1 - 3 and Comparative Examples 1 - 6, and control the thickness of the cemented carbide tool to be 3 mm: Flexural strength: Test according to GB / T232 - 2010, and use the three - point bending method to test the flexural strength; Impact resistance: Use the prepared cemented carbide tool as a cutting tool to cut 42CrMo steel. The cutting speed is 250 m / min, the cutting depth is 2 mm, and the feed rate is 0.5 mm / rev. Take the machining length completed when obvious chipping or breakage and other defects appear on the cutting tool as the evaluation standard, unit: m. The larger the machining length value, the better the impact resistance of the cemented carbide; Wear resistance: Use the prepared cemented carbide tool as a cutting tool to cut 42CrMo steel. The cutting speed is 250 m / min, the cutting depth is 2 mm, and the feed rate is 0.1 mm / rev. Take the machining length completed when the wear amount of the cutting tool reaches 0.1 mm as the evaluation standard, unit: m. The larger the machining length value, the better the wear resistance of the cemented carbide; Vickers hardness: Test the hardness at room temperature (HV) on a Vickers hardness tester with a load of 30 kg; According to the Nihara formula, calculate the fracture toughness (K IC ) from the radial crack length generated by the Vickers hardness indentation, unit: MPa·m 1 / 2 ; The test results are as follows: Table 1 Performance test results

[0041] The performance data of Example 1 and Comparative Example 1 show that sulfonylation modification of graphene oxide and introduction into the synthesis system of cemented carbide significantly improve the strength and hardness of the alloy; the lamellar structure of sulfonylated modified graphene forms a physical bridging at the grain boundaries, which can effectively inhibit crack propagation.

[0042] According to the test results of Example 1 and Comparative Example 2, it can be seen that the carboxyl group of citric acid forms a more stable polynuclear complex with metal ions, and at the same time, the hydroxyl group of citric acid forms a three-dimensional network structure with the groups of the complexing agent, promoting the uniform dispersion of metal ions and avoiding agglomeration defects, which plays an important role in enhancing the strength of the alloy.

[0043] According to the test results of Example 1 and Comparative Example 3, it can be seen that the etching process can effectively construct a porous structure and significantly improve the interfacial wettability of the alloy. Through the synergistic effect of freeze-drying and chemical etching, the interfacial wettability of the alloy is enhanced and the interfacial bonding strength of the material is improved.

[0044] According to the comparative analysis of Example 1 and Comparative Example 4, it can be seen that by using microwave sintering technology, the grains of the composite oxide can be further refined, the grain boundary density can be enhanced, and thus the strength of the alloy material can be improved.

[0045] According to the test results of Example 1 and Comparative Examples 5-6, it can be seen that by using a hybrid treatment process of nitrogen protection pre-sintering and argon protection microwave sintering, the synergistic regulation of interface activation and grain refinement is realized, and thus while improving toughness, the toughness is further improved, and the precise control of sintering is further realized.

[0046] This specific embodiment is only an explanation of the present invention, and it does not limit the present invention. Those skilled in the art can make modifications to this embodiment without creative contributions according to needs after reading this specification, but as long as it is within the scope of the claims of the present invention, it is protected by the patent law.

Claims

1. A cemented carbide tool, characterized in that: The invention comprises the following raw materials in parts by weight: 60-70 parts of WC powder, 8-12 parts of Ni powder, 5-8 parts of Mo2C powder, 2-4 parts of Si3N4 powder, 6-10 parts of strengthening phase, and 4-8 parts of improved additives.

2. A cemented carbide tool according to claim 1, characterized in that: The reinforcing phase is prepared by the following method: Disperse cobalt nitrate and yttrium nitrate in deionized water, stir for 10-15 minutes, add complexing agent, heat and stir for 30-45 minutes, add citric acid, heat to 80-100°C, stir for 5-7 hours, dry, heat treat, cool naturally, grind and sieve to obtain a reinforcing phase.

3. A cemented carbide tool according to claim 2, characterized in that: The reinforcing phase comprises the following components in parts by mass: 20-30 parts of cobalt nitrate, 8-12 parts of yttrium nitrate, 1-3 parts of a complexing agent, 10-15 parts of citric acid, and 70-80 parts of deionized water.

4. A cemented carbide tool according to claim 2, characterized in that: The complexing agent is prepared by the following method: A1. Disperse tartaric acid in dichloromethane, stir, then add copper sulfate and p-toluenesulfonyl chloride, stir, control the temperature at 4-8°C, stir for 4-6h, heat and stir, centrifuge, and vacuum dry to obtain sulfonylated tartaric acid; A2. Disperse sulfonylated tartaric acid in deionized water, add graphene oxide and 1-ethyl-(3-dimethylaminopropyl)carbodiimide, disperse by ultrasonication, adjust the pH, heat and stir for 4-6 hours, filter, and freeze-dry to obtain a complexing agent.

5. A cemented carbide tool according to claim 4, characterized in that: In the step A1, the following components are included in parts by mass: 8-12 parts of tartaric acid, 15-20 parts of p-toluenesulfonyl chloride, 0.2-0.5 parts of copper sulfate, and 70-80 parts of dichloromethane; in the step A2, the following components are included in parts by mass: 5-10 parts of sulfonylated tartaric acid, 2-4 parts of graphene oxide, 60-70 parts of deionized water, and 0.1-0.2 parts of 1-ethyl-(3-dimethylaminopropyl)carbodiimide.

6. A cemented carbide tool according to claim 1, characterized in that: The improved additive is prepared by the following method: B1. Add chromium formate and aluminum nitrate to deionized water, stir, add ferric nitrate, stir, add boric acid, adjust the pH, and obtain a mixed salt solution; B2. Disperse sodium alginate in deionized water, heat and stir, add calcium chloride, stir to obtain a sol; B3, adding the sol to the mixed salt solution, stirring, freeze-drying, and pre-calcining to obtain a composite oxide; The composite oxide is subjected to microwave sintering to obtain an intermediate, and the intermediate is added into an etching solution, soaked for 5-7 minutes, dried, ground and sieved to obtain an improved additive.

7. A cemented carbide tool according to claim 6, characterized in that: In the step B1, the following components are included in parts by mass: 3-6 parts of chromium formate, 5-8 parts of aluminum nitrate, 15-20 parts of ferric nitrate, 0.5-1 parts of boric acid, and 120-150 parts of deionized water; in the step B2, the following components are included in parts by mass: 2-4 parts of sodium alginate, 4-6 parts of calcium chloride, and 60-70 parts of deionized water; in the step B3, the mass ratio of the sol to the mixed salt solution is 30-45:60-70; the mass ratio of the intermediate to the etching solution is 15-18:25-30.

8. A method for preparing a cemented carbide tool according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1, weighing the raw materials in parts by mass; S2, mixing WC powder, Ni powder, Mo2C powder and Si3N4 powder for 20-30 minutes, ball milling, drying, pressing in a mold to obtain a green body, placing the green body in a tube furnace, sintering under nitrogen, grinding and sieving to obtain an intermediate product; S3. Mixing the intermediate product with the reinforcing phase and the improved additive, drying, pressing and forming in a mold, and microwave sintering under argon to obtain a cemented carbide tool.

9. The method for preparing a cemented carbide tool according to claim 8, characterized in that: The sintering treatment in step S2 includes: heating to 500-700°C at a heating rate of 8-15°C / min, and keeping warm for 45-70min; then heating to 800-900°C at a heating rate of 5-8°C / min, and keeping warm for 2-3h; then heating to 1000-1100°C at a heating rate of 3-5°C / min, and keeping warm for 1-2h.

10. The method for preparing a cemented carbide tool according to claim 8, characterized in that: The microwave sintering in step S3 includes: heating to 800-900°C at a heating rate of 50-80°C / min, keeping warm for 30-45min, controlling the microwave power to 3-6KW and the frequency to 2.45GHz; heating to 1350-1400°C at a heating rate of 10-20°C / min, keeping warm for 40-60min, controlling the microwave power to 1-2KW and the frequency to 2.45GHz.

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