Preparation method of hard alloy material based on high-entropy alloy bonding phase

Abstract

The invention provides a preparation method of a hard alloy material based on a high-entropy alloy bonding phase, and relates to the field of hard alloy materials, and the preparation method comprises the steps of S1, tungsten carbide powder pretreatment, S2, preparation of a WC-coated TiN core-shell structure, S3, in-situ synthesis of an interface wetting agent (Ti, Zr, Mo) CN, S4, wet high-energy ball milling and mixing, and S5, preparation of the hard alloy material. According to the hard alloy material prepared through the method, the limitation that traditional cobalt serves as a bonding phase is overcome, interface bonding between the high-entropy alloy and a tungsten carbide matrix is remarkably improved, abnormal growth of crystal grains is inhibited, generation of a brittle phase is avoided, and the hardness, toughness and high-temperature stability of the hard alloy material are remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of cemented carbide materials, and in particular to a method for preparing a cemented carbide material based on a high entropy alloy bonding phase. Background Art

[0002] Due to its excellent hardness, wear resistance and thermal stability, cemented carbide materials are widely used in high-load and high-wear scenarios such as cutting tools, forming molds and mining tools. Traditional cemented carbide materials are primarily composed of tungsten carbide (WC) and cobalt (Co) as a binder. Cobalt easily softens at medium to high temperatures (typically above 600°C), resulting in tungsten carbide particle shedding and a sharp decrease in the material's wear resistance when used in high-temperature conditions (such as high-speed cutting, heavy friction, or continuous heat exposure). Furthermore, cobalt is relatively chemically active, and in humid, acidic, and alkaline environments, the bonding phase, cobalt, is easily corroded, leading to a loose structure and particle shedding due to weakened bonding. Furthermore, cobalt is easily oxidized at high temperatures, forming a loose oxide layer that destroys the interface between the tungsten carbide particles and the cobalt bonding phase, causing surface shedding. Furthermore, the large difference in thermal expansion coefficients between tungsten carbide and cobalt can easily generate significant internal stress between them under conditions of drastic temperature fluctuations or repeated hot and cold cycles, which can cause cracking or interfacial delamination in the cemented carbide, greatly reducing its stability.

[0003] In recent years, high-entropy alloys (HEAs) have demonstrated great potential as a cobalt-replacing binder phase in tungsten carbide, thanks to their unique properties, including high entropy, lattice distortion, delayed diffusion, and "cocktail" effects. These alloys possess high melting points, excellent high-temperature strength, and softening resistance, effectively enhancing the oxidation and corrosion resistance of cemented carbide materials. However, HEAs require a uniform mixture of at least five elements and are highly sensitive to composition. During the composite process with tungsten carbide particles, they are prone to elemental segregation, leading to localized compositional inhomogeneities and abnormal grain growth. Furthermore, the interfacial wettability between HEAs and tungsten carbide particles is poor, and the composite easily forms pores or weakly bonded interfaces, resulting in a decrease in the overall mechanical properties of the cemented carbide. Furthermore, during high-temperature sintering or service, the active elements in the HEAs react with the tungsten carbide at the interface, generating a brittle phase that disrupts the bond between the tungsten carbide particles and the binder phase, resulting in a decrease in the material's strength and toughness. Summary of the Invention

[0004] In view of the problems existing in the above prior art, the object of the present invention is to provide a method for preparing a cemented carbide material based on a high-entropy alloy bonding phase. This method not only overcomes the limitations of traditional cobalt as a bonding phase through the composite between high-entropy alloy, multinary carbonitride and tungsten carbide matrix, but also significantly improves the interface bonding between high-entropy alloy and tungsten carbide matrix, inhibits abnormal grain growth, avoids the formation of brittle phase, and significantly improves the hardness, toughness and high-temperature stability of the material, thereby meeting the requirements of harsh working conditions such as aerospace, drilling exploration, and thermal processing.

[0005] The purpose of the present invention is achieved through the following technical solutions: A method for preparing a cemented carbide material based on a high entropy alloy bonding phase, comprising: Step S1, pretreatment of tungsten carbide powder: washing, drying and sieving the tungsten carbide powder in sequence to obtain tungsten carbide particles for standby use; Step S2, preparing a WC@TiN core-shell structure: first, the surface of the carbide particles pretreated in step S1 is pre-coated with TiO2 using a sol-gel method; then, the pre-coated TiO2 is converted into TiN through a nitriding sintering process to obtain a core-shell structure; Step S3, in-situ synthesis of an interfacial wetting agent (Ti, Zr, Mo)CN: First, the WC@TiN core-shell structure obtained in step S2 is uniformly mixed with Y2O3 nanopowder, so that the nanopowder is uniformly adsorbed on the surface of the core-shell structure; then, low-temperature zirconization, molybdenum layer deposition and carbonization treatment are sequentially performed to form a (Ti, Zr, Mo)CN gradient layer; Step S4, wet high-energy ball milling: wet high-energy ball milling the WC@TiN core-shell powder with the gradient layer in step S3 with the high-entropy alloy; Step S5, preparation of cemented carbide material: the slurry after ball milling in step S4 is subjected to vacuum freeze drying and step-by-step vacuum hot pressing sintering in sequence to obtain cemented carbide material.

[0006] Based on further optimization of the above scheme, the particle size of the tungsten carbide powder in step S1 is 0.2 to 5 μm; the cleaning step is specifically as follows: first, the tungsten carbide powder is ultrasonically cleaned for 25 to 35 minutes using a hydrochloric acid solution with a concentration of 4.5% to 5.5%, and then washed with deionized water until neutral; the drying step is specifically as follows: first, the washed carbide powder is placed in a vacuum drying oven, and dried for 1.5 to 2.5 hours at a vacuum degree of 500 to 700 Pa and a temperature of 75 to 85°C, and then the dried tungsten carbide powder is dispersed through a jet mill at a working pressure of 0.55 to 0.65 MPa to avoid agglomeration of the dried tungsten carbide powder.

[0007] Based on the further optimization of the above scheme, the sol-gel method is used in step S2 to achieve the pre-coating of TiO2 as follows: first, tetrabutyl titanate ( ) is slowly dripped into anhydrous ethanol and magnetically stirred for 28 to 32 minutes to form solution A; deionized water and anhydrous ethanol are then mixed in a volume ratio of 1:1, and the pH value is adjusted to 3.5 to 4.0 with ammonia water to form solution B; thereafter, solution B is slowly dripped into solution A and stirred for 1 to 1.5 hours to obtain a transparent sol; the tungsten carbide powder pretreated in step S1 is added to the transparent sol, ultrasonically dispersed, magnetically stirred, and then solvent evaporation, vacuum freeze drying and calcination are carried out in sequence to obtain a TiO2 pre-coated tungsten carbide powder structure.

[0008] Based on further optimization of the above scheme, when the tungsten carbide powder is added to the transparent sol, the solid-liquid ratio is 0.8-1.2:4.8-5.2, ultrasonic dispersion is carried out at 25-35° C. for 28-32 minutes, and magnetic stirring is carried out for 1.8-2.2 hours.

[0009] Based on further optimization of the above scheme, the solvent evaporation is specifically as follows: the mixed system after the tungsten carbide powder is added to the transparent sol is evaporated in a water bath at 55-65°C for 2-3 hours to obtain wet gel particles; the vacuum freeze drying is specifically as follows: the wet gel particles are placed in a vacuum freeze dryer and dried for 11-13 hours at -55--45°C and a vacuum degree of 0.8-1.2 Pa; the calcination is specifically as follows: the dried gel particles are heated to 480-520°C at a heating rate of 4.5-5.5°C / min in an air atmosphere, and kept warm for 1.8-2.2 hours to obtain a TiO2 pre-coated tungsten carbide powder structure; wherein the thickness of the TiO2 coating layer is 50-100nm.

[0010] Based on the further optimization of the above scheme, the nitriding sintering process in step S2 is specifically as follows: the TiO2 pre-coated tungsten carbide powder structure is loaded into a graphite boat, and the graphite boat is placed in a tube furnace, and high-purity nitrogen (purity 99.99%) is introduced to completely fill the tube furnace with nitrogen, the nitrogen flow rate is 480-520 mL / min, and the vacuum degree is 10 -3 Pa; then, the temperature was first increased to 800-850°C at a heating rate of 9.5-10.5°C / min and kept warm for 0.8-1.2h, and then the temperature was increased to 1050-1150°C at a heating rate of 4.5-5.5°C / min and kept warm for 2.8-3.2h, so that TiO2 was completely converted into TiN (TiO2 conversion rate was greater than 99%), and a WC@TiN core-shell structure was obtained.

[0011] Based on further optimization of the above scheme, the WC@TiN core-shell structure and the Y2O3 nanopowder are uniformly mixed in step S3 as follows: the WC@TiN core-shell structure and the Y2O3 nanopowder are mixed in a mass ratio of 99-101:0.08-0.12, and anhydrous ethanol is added, and the solid-liquid ratio between anhydrous ethanol and the mixed powder is 0.8-1.2:3.8-4.2; then, mixing is carried out in a planetary ball mill at a speed of 200-250 rpm for 28-32 minutes, so that the Y2O3 nanoparticles are uniformly adsorbed on the TiN surface of the WC@TiN core-shell structure; after mixing, the mixture is transferred to a vacuum drying oven and dried at a vacuum degree of 500-700 Pa and a temperature of 75-85°C for 1.8-2.2 hours.

[0012] Based on further optimization of the above scheme, the low-temperature zirconization in step S3 is specifically as follows: a WC@TiN core-shell structure with Y2O3 nanoparticles adsorbed on the surface is mixed with zirconium nitrate in a ratio of 0.8-1.2:4.8-5.2 of the atomic ratio of zirconium to titanium, and placed in a tubular furnace. The mixture is heated to 580-620°C at a heating rate of 4.5-5.5°C / min with nitrogen at a nitrogen flow rate of 280-320 mL / min, and kept warm for 1.8-2.2 h to obtain a TiN-ZrN solid solution transition layer.

[0013] Based on further optimization of the above scheme, the molybdenum layer deposition in step S3 is specifically as follows: the powder after low-temperature zirconization is transferred to a fluidized bed reactor, and the temperature is raised to 280-320°C at a heating rate of 4-5°C / min using argon gas and a gas flow rate of 180-220 mL / min, and then gaseous Mo(CO)6 is introduced according to an atomic ratio of molybdenum to zirconium of 0.9-1.1:0.9-1.1, and the temperature is kept for 0.8-1.2h, so that a nano-molybdenum layer is deposited on the surface of the TiN-ZrN solid solution transition layer; the thickness of the nano-molybdenum layer is 50-100nm.

[0014] Based on further optimization of the above scheme, the carbonization treatment in step S3 is specifically as follows: after depositing a nano-molybdenum layer on the surface of the TiN-ZrN solid solution transition layer, the argon atmosphere is replaced by a mixed gas of methane and hydrogen, the volume ratio of methane to hydrogen is 0.9-1.1:2.9-3.1, and the flow rate of the mixed gas is 220-280 mL / min; then, the temperature is increased to 780-820°C at a heating rate of 5-6°C / min and kept at this temperature for 1.8-2.2 hours, and the nano-molybdenum layer reacts with carbon and nitrogen to combine with the TiN-ZrN solid solution to form a (Ti, Zr, Mo)CN gradient layer.

[0015] Based on the further optimization of the above scheme, the high entropy alloy in step S4 is AlCoCrFeNiTi a Cu b, a is 0.75-0.85, b is 0.15-0.25 and a+b=1; the high entropy alloy is prepared by a gas atomization method, and the particle size of the high entropy alloy powder is 1-5 μm.

[0016] Based on further optimization of the above scheme, the wet high-energy ball milling mixing in step S4 is specifically as follows: the WC@TiN core-shell powder with the gradient layer is mixed with the high-entropy alloy powder in a mass percentage of 70-97%:3-30%, and anhydrous ethanol is added, and the solid-liquid ratio of anhydrous ethanol to the mixed powder is 0.8-1.2:2.8-3.2, and 0.45-0.55wt% PEG-4000 is added at the same time; the above mixed slurry is placed in a planetary ball mill, using zirconia balls with a diameter of 5 mm, a ball-to-material ratio of 8-10:1, a rotation speed of 350-450 rpm, and an intermittent reverse ball milling cycle of "30 min forward rotation + 5 min stop + 30 min reverse rotation + 5 min stop + 30 min forward rotation" is adopted, and ball milling is carried out for 18-22 hours.

[0017] Based on further optimization of the above scheme, the vacuum freeze drying in step S5 is as follows: the ball-milled slurry is transferred into a vacuum freeze dryer and dried at -52 to -48°C and a vacuum degree of 0.8 to 1.2 Pa for 10 to 12 hours.

[0018] Based on the further optimization of the above scheme, the step-by-step vacuum hot pressing sintering in step S5 is specifically as follows: when the vacuum degree is ≤1x10 -3 Pa environment, first heat the temperature to 580-620℃ at a heating rate of 9-11℃ / min and keep warm for 0.8-1.2h; then fill the furnace with high-purity nitrogen (purity 99.99%) to 0.1MPa, heat the temperature to 1130-1170℃ at a heating rate of 5-6℃ / min, keep warm for 30-35min, then heat the temperature to 1260-1300℃ at a heating rate of 8-10℃ / min, keep warm for 15-20min, and finally heat the temperature to 1400-1440℃ at a heating rate of 80-100℃ / min, apply a pressure of 30-50MPa, and keep warm for 8-12min.

[0019] Based on further optimization of the above scheme, after the step-by-step vacuum hot pressing sintering in step S5 is completed, the pressure is first released to 4.5-5.5 MPa, and then the temperature is cooled to 1000-1050°C at a cooling rate of 4-6°C / min; thereafter, the heating device is turned off, and nitrogen is continuously introduced, and the furnace is naturally cooled to room temperature to obtain a dense cemented carbide material.

[0020] The following are the technical effects of this solution: The present invention prepares the WC@TiN core-shell structure by the sol-gel method and the nitriding sintering process, which not only effectively avoids the difference in thermal expansion coefficient between tungsten carbide and TiN (the thermal expansion coefficient of tungsten carbide is 5.5x10 -6 / K, TiN thermal expansion coefficient is 9.4x10 -6 / K) causes cracking and spalling during the sintering cooling process. The TiN layer also acts as a diffusion barrier, preventing some elements in the high-entropy alloy from directly reacting with tungsten carbide during sintering, forming brittle ternary carbides. Subsequently, the core-shell structure is mixed with Y2O3 nanopowder and sequentially subjected to low-temperature zirconization, molybdenum deposition, and carbonization. This creates an in-situ (Ti, Zr, Mo)CN gradient layer that is structurally compatible with the TiN layer, forming a continuous gradient interface. This not only ensures the bonding strength and uniform distribution of the (Ti, Zr, Mo)CN wetting phase between the (Ti, Zr, Mo)CN and the tungsten carbide matrix, but also reduces the contact angle between the high-entropy alloy solution and tungsten carbide, improving the spreadability of liquid-phase sintering. It also prevents the diffusion of elements during ball milling and sintering, preventing the formation of brittle phases and improving the overall hardness and flexural strength of the cemented carbide. Furthermore, it effectively avoids component segregation caused by high-temperature reactions and inhibits abnormal grain growth, ensuring the uniformity of the cemented carbide microstructure and ensuring fine, dense grains.

[0021] The hard alloy material prepared by the invention has uniform microstructure and fine grains, can maintain high hardness and strength at high temperatures, and has excellent wear resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 1 is a flow chart of the preparation process of cemented carbide material in an embodiment of the present invention.

[0023] Figure 2 Schematic diagram of wet high-energy ball milling mixing in an embodiment of the present invention; wherein, Figure 2 (a) is a schematic diagram of wet high-energy ball milling equipment. Figure 2 (b) Schematic diagram of intermittent reverse ball milling cycle.

[0024] Figure 3 : This is a scanning electron microscope image of the cemented carbide material in the embodiment of the present invention. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0026] Example 1: A method for preparing a cemented carbide material based on a high entropy alloy bonding phase, comprising: Step S1, tungsten carbide powder pretreatment: tungsten carbide powder with a particle size of 0.2 to 5 μm is washed, dried and sieved in sequence to obtain tungsten carbide particles for standby use; cleaning is specifically: first, the tungsten carbide powder is ultrasonically cleaned with a 4.5% hydrochloric acid solution for 35 minutes, and then washed with deionized water until neutral; drying is specifically: first, the washed carbide powder is placed in a vacuum drying oven, and dried at a vacuum degree of 500 Pa and a temperature of 75°C for 2.5 hours, and then the dried tungsten carbide powder is dispersed through a jet mill at a working pressure of 0.55 MPa to avoid agglomeration of the dried tungsten carbide powder; sieving is to screen tungsten carbide particles that meet the particle size requirements from the washed and dried tungsten carbide particles to avoid potential agglomeration resulting in excessive particle size of the tungsten carbide particles.

[0027] Step S2, preparation of WC@TiN core-shell structure: using sol-gel method to pre-coat TiO2 on the surface of carbide particles pre-treated in step S1, specifically: first, tetrabutyl titanate ( ) was slowly dripped into anhydrous ethanol and magnetically stirred for 28 minutes to form solution A; deionized water and anhydrous ethanol were then mixed in a volume ratio of 1:1, and the pH value was adjusted to 3.5-4.0 with aqueous ammonia to form solution B; thereafter, solution B was slowly dripped into solution A and stirred for 1 hour to obtain a transparent sol; the tungsten carbide powder pretreated in step S1 was added to the transparent sol with a solid-liquid ratio (i.e., the ratio of tungsten carbide powder to transparent sol) of 0.8:4.8, and ultrasonic dispersion was carried out at 25°C for 32 minutes, and magnetic stirring was carried out for 2.2 hours. Then, solvent evaporation, vacuum freeze drying and calcination are carried out in sequence to obtain a TiO2 pre-coated tungsten carbide powder structure; solvent evaporation is as follows: the mixed system after adding tungsten carbide powder to transparent sol is evaporated in a water bath at 55°C for 3 hours to obtain wet gel particles; vacuum freeze drying is as follows: the wet gel particles are placed in a vacuum freeze dryer and dried at -45°C and a vacuum degree of 0.8 Pa for 13 hours; calcination is as follows: the dried gel particles are heated to 480°C at a heating rate of 4.5°C / min in an air atmosphere and kept warm for 2.2 hours to obtain a TiO2 pre-coated tungsten carbide powder structure; wherein the thickness of the TiO2 coating layer is 50nm.

[0028] Then, the pre-coated TiO2 was converted into TiN through a nitriding sintering process to obtain a core-shell structure. Specifically, the TiO2 pre-coated tungsten carbide powder structure was loaded into a graphite boat, and the graphite boat was placed in a tube furnace. High-purity nitrogen (purity 99.99%) was introduced until the nitrogen completely filled the tube furnace. The nitrogen flow rate was 480 mL / min and the vacuum degree was 10 -3Pa; then, the temperature was first increased to 800°C at a heating rate of 9.5°C / min and kept warm for 1.2h, and then the temperature was increased to 1050°C at a heating rate of 4.5°C / min and kept warm for 3.2h, so that TiO2 was completely converted into TiN (TiO2 conversion rate was greater than 99%), and a WC@TiN core-shell structure was obtained.

[0029] Step S3, in situ synthesis of interfacial wetting agent (Ti, Zr, Mo) CN: the WC@TiN core-shell structure obtained in step S2 is uniformly mixed with Y2O3 nanopowder, so that the nanopowder is uniformly adsorbed on the surface of the core-shell structure; specifically, the WC@TiN core-shell structure and Y2O3 nanopowder are mixed in a mass ratio of 99:0.08, and anhydrous ethanol is added, and the solid-liquid ratio between anhydrous ethanol and the mixed powder is 0.8:3.8; then, the mixture is mixed in a planetary ball mill at a speed of 200 rpm for 32 minutes, so that the Y2O3 nanoparticles are uniformly adsorbed on the TiN surface of the WC@TiN core-shell structure; after mixing, the mixture is transferred to a vacuum drying oven and dried at a vacuum degree of 500 Pa and a temperature of 75°C for 2.2 hours.

[0030] Then, low-temperature zirconization, molybdenum layer deposition, and carbonization were sequentially performed to form a (Ti, Zr, Mo)CN gradient layer. The low-temperature zirconization step involved mixing a WC@TiN core-shell structure with Y2O3 nanoparticles adsorbed on its surface with zirconium nitrate at an atomic ratio of 0.8:4.8. The mixture was placed in a tube furnace and heated to 580°C at a rate of 4.5°C / min using nitrogen at a flow rate of 280 mL / min. The temperature was then maintained for 2.2 hours, resulting in a TiN-ZrN solid solution transition layer. The molybdenum layer was deposited by transferring the low-temperature zirconized powder to a fluidized bed reactor and heating to 280°C at a rate of 4°C / min using argon at a flow rate of 180 mL / min. Then, gaseous Mo(CO)6 was introduced at an atomic ratio of 0.9:1.1 using zirconium to zirconium. The temperature was maintained for 1.2 hours, resulting in a 50 nm thick nano-Mo layer deposited on the surface of the TiN-ZrN solid solution transition layer. The carbonization treatment is as follows: after depositing a nano-molybdenum layer on the surface of the TiN-ZrN solid solution transition layer, the argon atmosphere is replaced by a mixed gas of methane and hydrogen, with a volume ratio of methane to hydrogen of 0.9:2.9 and a flow rate of the mixed gas of 220 mL / min; then, the temperature is raised to 780°C at a heating rate of 5°C / min and kept at this temperature for 2.2 hours. The nano-molybdenum layer reacts with carbon and nitrogen and combines with the TiN-ZrN solid solution to form a (Ti, Zr, Mo)CN gradient layer.

[0031] Step S4, wet high energy ball milling: wet high energy ball milling the WC@TiN core-shell powder with gradient layer in step S3 with high entropy alloy; the high entropy alloy is AlCoCrFeNiTi a Cub , a is 0.75, b is 0.25; the high entropy alloy is prepared by gas atomization method, and the particle size of the high entropy alloy powder is 1 to 5 μm.

[0032] The wet high-energy ball milling mixing is specifically as follows: the WC@TiN core-shell powder with the gradient layer is mixed with the high-entropy alloy powder in a mass percentage of 70%:30%, and anhydrous ethanol is added, and the solid-liquid ratio of anhydrous ethanol to the mixed powder is 0.8:2.8, and 0.45wt% PEG-4000 is added at the same time; the above mixed slurry is placed in a planetary ball mill, using zirconia balls with a diameter of 5mm, a ball-to-material ratio of 8:1, a rotation speed of 350rpm, and an intermittent reverse ball milling cycle of "30min forward rotation + 5min stop + 30min reverse rotation + 5min stop + 30min forward rotation" for 22h.

[0033] Step S5, preparation of cemented carbide material: vacuum freeze drying and step-by-step vacuum hot pressing sintering are carried out on the slurry after ball milling in step S4. Vacuum freeze drying is as follows: the slurry after ball milling is transferred into a vacuum freeze dryer and dried at -48°C and 0.8 Pa vacuum for 12 hours; step-by-step vacuum hot pressing sintering ... -3 Pa environment, first heat the temperature to 580℃ at a heating rate of 9℃ / min and keep it warm for 1.2h; then fill the furnace with high-purity nitrogen (purity 99.99%) to 0.1MPa, heat the temperature to 1130℃ at a heating rate of 5℃ / min and keep it warm for 35min, then heat the temperature to 1260℃ at a heating rate of 8℃ / min and keep it warm for 20min, finally heat the temperature to 1400℃ at a heating rate of 80℃ / min, apply 30MPa pressure and keep it warm for 12min. After the step-by-step vacuum hot pressing sintering is completed, the pressure is first released to 5.5MPa, and then the temperature is cooled to 1050℃ at a cooling rate of 4℃ / min; then, the heating device is turned off, and nitrogen is continuously introduced, and the furnace is naturally cooled to room temperature to obtain a dense cemented carbide material.

[0034] Example 2: A method for preparing a cemented carbide material based on a high entropy alloy bonding phase, comprising: Step S1, tungsten carbide powder pretreatment: tungsten carbide powder with a particle size of 0.2 to 5 μm is washed, dried and sieved in sequence to obtain tungsten carbide particles for standby use; cleaning is specifically: first, the tungsten carbide powder is ultrasonically cleaned with a 5% hydrochloric acid solution for 30 minutes, and then washed with deionized water until neutral; drying is specifically: first, the washed carbide powder is placed in a vacuum drying oven, and dried at a vacuum degree of 600 Pa and a temperature of 80°C for 2 hours, and then the dried tungsten carbide powder is dispersed through a jet mill at a working pressure of 0.6 MPa to avoid agglomeration of the dried tungsten carbide powder; sieving is to screen tungsten carbide particles that meet the particle size requirements from the washed and dried tungsten carbide particles to avoid potential agglomeration resulting in excessive particle size of the tungsten carbide particles.

[0035] Step S2, preparation of WC@TiN core-shell structure: using sol-gel method to pre-coat TiO2 on the surface of carbide particles pre-treated in step S1, specifically: first, tetrabutyl titanate ( ) was slowly dripped into anhydrous ethanol and magnetically stirred for 30 minutes to form solution A; deionized water and anhydrous ethanol were then mixed in a volume ratio of 1:1, and the pH value was adjusted to 3.5-4.0 with ammonia water to form solution B; thereafter, solution B was slowly dripped into solution A and stirred for 1.2 hours to obtain a transparent sol; the tungsten carbide powder pretreated in step S1 was added to the transparent sol with a solid-liquid ratio (i.e., the ratio of tungsten carbide powder to transparent sol) of 1:5, and ultrasonic dispersion was carried out at 30°C for 30 minutes, and magnetic stirring was carried out for 2 hours. Then, solvent evaporation, vacuum freeze drying and calcination are carried out in sequence to obtain a TiO2 pre-coated tungsten carbide powder structure; solvent evaporation is as follows: the mixed system after adding tungsten carbide powder to transparent sol is evaporated in a water bath at 60°C for 2.5 hours to obtain wet gel particles; vacuum freeze drying is as follows: the wet gel particles are placed in a vacuum freeze dryer and dried at -50°C and a vacuum degree of 1Pa for 12 hours; calcination is as follows: the dried gel particles are heated to 500°C at a heating rate of 5°C / min in an air atmosphere and kept warm for 2 hours to obtain a TiO2 pre-coated tungsten carbide powder structure; wherein the thickness of the TiO2 coating layer is 75nm.

[0036] Then, the pre-coated TiO2 was converted into TiN through a nitriding sintering process to obtain a core-shell structure. Specifically, the TiO2 pre-coated tungsten carbide powder structure was loaded into a graphite boat, and the graphite boat was placed in a tube furnace. High-purity nitrogen (purity 99.99%) was introduced until the nitrogen completely filled the tube furnace. The nitrogen flow rate was 500 mL / min and the vacuum degree was 10 -3Pa; then, the temperature was first increased to 825°C at a heating rate of 10°C / min and kept for 1 hour, and then increased to 1100°C at a heating rate of 5°C / min and kept for 3 hours, so that TiO2 was completely converted into TiN (TiO2 conversion rate was greater than 99%), and a WC@TiN core-shell structure was obtained.

[0037] Step S3, in situ synthesis of interfacial wetting agent (Ti, Zr, Mo) CN: the WC@TiN core-shell structure obtained in step S2 is uniformly mixed with Y2O3 nanopowder, so that the nanopowder is uniformly adsorbed on the surface of the core-shell structure; specifically, the WC@TiN core-shell structure and Y2O3 nanopowder are mixed in a mass ratio of 100:0.1, and anhydrous ethanol is added, and the solid-liquid ratio between anhydrous ethanol and the mixed powder is 1:4; then, the mixture is mixed in a planetary ball mill at a speed of 225 rpm for 30 minutes, so that the Y2O3 nanoparticles are uniformly adsorbed on the TiN surface of the WC@TiN core-shell structure; after mixing, the mixture is transferred to a vacuum drying oven and dried at a vacuum degree of 600 Pa and a temperature of 80°C for 2 hours.

[0038] Subsequently, low-temperature zirconization, molybdenum layer deposition, and carbonization were sequentially performed to form a (Ti, Zr, Mo)CN gradient layer. Low-temperature zirconization involved mixing a WC@TiN core-shell structure with Y2O3 nanoparticles adsorbed on its surface with zirconium nitrate in a zirconium-to-titanium atomic ratio of 1:5. The mixture was placed in a tube furnace and heated to 600°C at a rate of 5°C / min using nitrogen at a flow rate of 300 mL / min, followed by a 2-hour holding period to form a TiN-ZrN solid solution transition layer. Molybdenum layer deposition involved transferring the low-temperature zirconized powder to a fluidized bed reactor and heating to 300°C at a rate of 4.5°C / min using argon at a flow rate of 200 mL / min. Gaseous Mo(CO)6 was then introduced in a molybdenum-to-zirconium atomic ratio of 1:1 and held for 1 hour, resulting in a 75nm thick nano-molybdenum layer deposited on the surface of the TiN-ZrN solid solution transition layer. The carbonization treatment is as follows: after depositing a nano-molybdenum layer on the surface of the TiN-ZrN solid solution transition layer, the argon atmosphere is replaced by a mixed gas of methane and hydrogen, with a volume ratio of methane to hydrogen of 1:3 and a flow rate of the mixed gas of 250 mL / min; then, the temperature is raised to 800°C at a heating rate of 5.5°C / min and kept for 2 hours. The nano-molybdenum layer reacts with carbon and nitrogen and combines with the TiN-ZrN solid solution to form a (Ti, Zr, Mo)CN gradient layer.

[0039] Step S4, wet high energy ball milling: wet high energy ball milling the WC@TiN core-shell powder with gradient layer in step S3 with high entropy alloy; the high entropy alloy is AlCoCrFeNiTi a Cu b, a is 0.8, b is 0.2; the high entropy alloy is prepared by gas atomization method, and the particle size of the high entropy alloy powder is 1 to 5 μm.

[0040] The wet high-energy ball milling mixing is specifically as follows: the WC@TiN core-shell powder with the gradient layer is mixed with the high-entropy alloy powder in a mass percentage of 83%:17%, and anhydrous ethanol is added, and the solid-liquid ratio of anhydrous ethanol to the mixed powder is 1:3, and 0.5wt% PEG-4000 is added at the same time; the above mixed slurry is placed in a planetary ball mill, using zirconia balls with a diameter of 5mm, a ball-to-material ratio of 9:1, a rotation speed of 400rpm, and an intermittent reverse ball milling cycle of "30min forward rotation + 5min stop + 30min reverse rotation + 5min stop + 30min forward rotation" for 20h.

[0041] Step S5, preparation of cemented carbide material: vacuum freeze drying and step-by-step vacuum hot pressing sintering are carried out on the slurry after ball milling in step S4. Vacuum freeze drying is as follows: the slurry after ball milling is transferred into a vacuum freeze dryer and dried at -50°C and 1Pa for 11 hours; step-by-step vacuum hot pressing sintering is as follows: the slurry after ball milling is transferred into a vacuum freeze dryer and dried at a vacuum degree of ...x10 -3 Pa environment, first heat the temperature to 600°C at a heating rate of 10°C / min and keep warm for 1h; then fill the furnace with high-purity nitrogen (purity 99.99%) to 0.1MPa, heat the furnace to 1150°C at a heating rate of 5.5°C / min and keep warm for 33min, then heat the furnace to 1280°C at a heating rate of 9°C / min and keep warm for 17min, finally heat the furnace to 1420°C at a heating rate of 90°C / min, apply a pressure of 40MPa, and keep warm for 10min. After the step-by-step vacuum hot pressing sintering is completed, the pressure is first released to 5 MPa, and then the temperature is cooled to 1025°C at a cooling rate of 5°C / min; then, the heating device is turned off, and nitrogen is continuously introduced, and the furnace is naturally cooled to room temperature to obtain a dense cemented carbide material.

[0042] Example 3: A method for preparing a cemented carbide material based on a high entropy alloy bonding phase, comprising: Step S1, tungsten carbide powder pretreatment: tungsten carbide powder with a particle size of 0.2 to 5 μm is washed, dried and sieved in sequence to obtain tungsten carbide particles for standby use; cleaning is specifically: first, the tungsten carbide powder is ultrasonically cleaned with a 5.5% hydrochloric acid solution for 25 minutes, and then washed with deionized water until neutral; drying is specifically: first, the washed carbide powder is placed in a vacuum drying oven, and dried at a vacuum degree of 700 Pa and a temperature of 85°C for 1.5 hours, and then the dried tungsten carbide powder is dispersed through a jet mill at a working pressure of 0.65 MPa to avoid agglomeration of the dried tungsten carbide powder; sieving is to screen tungsten carbide particles that meet the particle size requirements from the washed and dried tungsten carbide particles to avoid potential agglomeration resulting in excessive particle size of the tungsten carbide particles.

[0043] Step S2, preparation of WC@TiN core-shell structure: using sol-gel method to pre-coat TiO2 on the surface of carbide particles pre-treated in step S1, specifically: first, tetrabutyl titanate ( ) was slowly dripped into anhydrous ethanol and magnetically stirred for 32 minutes to form solution A; deionized water and anhydrous ethanol were then mixed in a volume ratio of 1:1, and the pH value was adjusted to 3.5-4.0 with ammonia water to form solution B; thereafter, solution B was slowly dripped into solution A and stirred for 1.5 hours to obtain a transparent sol; the tungsten carbide powder pretreated in step S1 was added to the transparent sol with a solid-liquid ratio (i.e., the ratio of tungsten carbide powder to transparent sol) of 1.2:5.2, and ultrasonic dispersion was carried out at 35°C for 28 minutes, followed by magnetic stirring for 1.8 hours. Then, solvent evaporation, vacuum freeze drying and calcination are carried out in sequence to obtain a TiO2 pre-coated tungsten carbide powder structure; solvent evaporation is as follows: the mixed system after adding tungsten carbide powder to transparent sol is evaporated in a water bath at 65°C for 2 hours to obtain wet gel particles; vacuum freeze drying is as follows: the wet gel particles are placed in a vacuum freeze dryer and dried at -55°C and a vacuum degree of 1.2 Pa for 11 hours; calcination is as follows: the dried gel particles are heated to 520°C at a heating rate of 5.5°C / min in an air atmosphere and kept warm for 1.8 hours to obtain a TiO2 pre-coated tungsten carbide powder structure; wherein the thickness of the TiO2 coating layer is 100nm.

[0044] Then, the pre-coated TiO2 was converted into TiN through a nitriding sintering process to obtain a core-shell structure. Specifically, the TiO2 pre-coated tungsten carbide powder structure was loaded into a graphite boat, and the graphite boat was placed in a tube furnace. High-purity nitrogen (purity 99.99%) was introduced until the nitrogen completely filled the tube furnace. The nitrogen flow rate was 520 mL / min and the vacuum degree was 10 -3Pa; then, the temperature was first increased to 850°C at a heating rate of 10.5°C / min and kept for 0.8h, and then increased to 1150°C at a heating rate of 5.5°C / min and kept for 2.8h, so that TiO2 was completely converted into TiN (TiO2 conversion rate was greater than 99%), and a WC@TiN core-shell structure was obtained.

[0045] Step S3, in situ synthesis of an interfacial wetting agent (Ti, Zr, Mo) CN: The WC@TiN core-shell structure obtained in step S2 is uniformly mixed with Y2O3 nanopowder so that the nanopowder is uniformly adsorbed on the surface of the core-shell structure; specifically, the WC@TiN core-shell structure and Y2O3 nanopowder are mixed in a mass ratio of 101:0.12, and anhydrous ethanol is added, with a solid-liquid ratio of anhydrous ethanol to the mixed powder being 1.2:4.2; then, the mixture is mixed in a planetary ball mill at a speed of 250 rpm for 28 minutes so that the Y2O3 nanoparticles are uniformly adsorbed on the TiN surface of the WC@TiN core-shell structure; after mixing, the mixture is transferred to a vacuum drying oven and dried at a vacuum degree of 700 Pa and a temperature of 85°C for 1.8 hours.

[0046] Then, low-temperature zirconization, molybdenum layer deposition, and carbonization were sequentially performed to form a (Ti, Zr, Mo)CN gradient layer. Low-temperature zirconization involved mixing a WC@TiN core-shell structure with Y2O3 nanoparticles adsorbed on its surface with zirconium nitrate at an atomic ratio of 1.2:5.2. The mixture was placed in a tube furnace and heated to 620°C at a rate of 5.5°C / min using nitrogen at a flow rate of 320 mL / min. The temperature was then maintained for 1.8 hours, resulting in a TiN-ZrN solid solution transition layer. Molybdenum layer deposition involved transferring the low-temperature zirconized powder to a fluidized bed reactor and heating to 320°C at a rate of 5°C / min using argon at a flow rate of 220 mL / min. Then, gaseous Mo(CO)6 was introduced at an atomic ratio of 1.1:0.9 using zirconium to zirconium. The temperature was maintained for 0.8 hours, resulting in a 100 nm thick nano-Mo layer deposited on the surface of the TiN-ZrN solid solution transition layer. The carbonization treatment is as follows: after depositing a nano-molybdenum layer on the surface of the TiN-ZrN solid solution transition layer, the argon atmosphere is replaced by a mixed gas of methane and hydrogen, with a volume ratio of methane to hydrogen of 1.1:3.1 and a flow rate of the mixed gas of 280 mL / min; then, the temperature is raised to 820°C at a heating rate of 6°C / min and kept at that temperature for 1.8 hours. The nano-molybdenum layer reacts with carbon and nitrogen and combines with the TiN-ZrN solid solution to form a (Ti, Zr, Mo)CN gradient layer.

[0047] Step S4, wet high energy ball milling: wet high energy ball milling the WC@TiN core-shell powder with gradient layer in step S3 with high entropy alloy; the high entropy alloy is AlCoCrFeNiTi a Cub , a is 0.85, b is 0.15; the high entropy alloy is prepared by gas atomization method, and the particle size of the high entropy alloy powder is 1 to 5 μm.

[0048] The wet high-energy ball milling mixing is specifically as follows: the WC@TiN core-shell powder with the gradient layer is mixed with the high-entropy alloy powder in a mass percentage of 97%:3, and anhydrous ethanol is added, and the solid-liquid ratio of anhydrous ethanol to the mixed powder is 1.2:3.2, and 0.55wt% PEG-4000 is added at the same time; the above mixed slurry is placed in a planetary ball mill, using zirconia balls with a diameter of 5mm, a ball-to-material ratio of 10:1, a rotation speed of 350-450rpm, and an intermittent reverse ball milling cycle of "30min forward rotation + 5min stop + 30min reverse rotation + 5min stop + 30min forward rotation" for 18-22h.

[0049] Step S5, preparation of cemented carbide material: vacuum freeze drying and step-by-step vacuum hot pressing sintering are carried out on the slurry after ball milling in step S4. Vacuum freeze drying is as follows: the slurry after ball milling is transferred into a vacuum freeze dryer and dried at -52°C and 1.2 Pa vacuum for 10 h; step-by-step vacuum hot pressing sintering ... -3 Pa environment, first heat the temperature to 620℃ at a heating rate of 11℃ / min and keep it warm for 0.8h; then fill the furnace with high-purity nitrogen (purity 99.99%) to 0.1MPa, heat the temperature to 1170℃ at a heating rate of 6℃ / min and keep it warm for 30min, then heat the temperature to 1300℃ at a heating rate of 10℃ / min and keep it warm for 15min, finally heat the temperature to 1440℃ at a heating rate of 100℃ / min, apply a pressure of 50MPa, and keep it warm for 8min. After the step-by-step vacuum hot pressing sintering is completed, the pressure is first released to 4.5MPa, and then the temperature is cooled to 1000℃ at a cooling rate of 6℃ / min; after that, the heating device is turned off and nitrogen is continuously introduced, and the furnace is naturally cooled to room temperature to obtain a dense cemented carbide material.

[0050] Example 4: As a further preferred embodiment of the present invention, based on any one of Examples 1 to 3, a high entropy alloy AlCoCrFeNiTi is prepared by gas atomization. a Cu b The specific steps are: First, use metal elements Al, Co, Cr, Fe, Ni, Ti, and Cu with a purity of no less than 99.99% and accurately weigh them according to the corresponding atomic ratio. Ti and Al are purified using boric anhydride. Dry boric anhydride and the metal are placed in a test tube and heated until melted, allowing the boric anhydride to dissolve the surface oxides and float above the liquid metal. Co, Cr, Fe, Ni, and Cu can be mechanically polished or pickled to remove the oxide layer. Then, vacuum is applied to a vacuum induction melting furnace (VIGA) or an induction melting furnace without crucible (EIGA) to a temperature of ≤1×10 -3 Pa, and fill with high-purity argon (purity 99.99%) to semi-atmospheric pressure, repeat 3 to 5 times to reduce the oxygen content; heat to 1600 ~ 1800 ℃ , maintain the melting current at 245-255A and the melting time for 30-60s, during which the alloy ingot is turned over at least 4 times, and after melting, it is quickly cast into a water-cooled copper mold to form a master alloy ingot with uniform composition; Afterwards, an annular gap nozzle is used with an annular gap width of 0.5-1.5 mm, an atomization angle of 45°-70°, and an outlet diameter of 13-17 mm. The atomization parameters are: high-purity argon (99.999%), pressure of 3-5 MPa, temperature of -30-0°C, the master alloy is reheated to 1600-1800°C, and flows out through the guide tube at a rate of 5-8 kg / min, and collided with the high-speed argon gas. The droplet cooling rate reaches 10 5 ~10 6 K / s, forming nanocrystalline or amorphous structure; the powder after atomization is collected at the bottom of the atomization tower and sieved by air flow classification to obtain a powder with a particle size of 15-60μm and a sphericity of ≥98%; Finally, the high entropy alloy AlCoCrFeNiTi was obtained by vacuum annealing at 500-900℃ for 2h. a Cu b .

[0051] Comparative Example 1: A method for preparing a cemented carbide material, comprising: Step S1, tungsten carbide powder pretreatment: the same as step S1 in Example 2.

[0052] Step S2, preparing a WC@TiN core-shell structure: a TiN layer is prepared on the surface of the pretreated tungsten carbide powder by chemical vapor deposition, that is, the pretreated tungsten carbide powder is placed in a chemical vapor deposition reactor, nitrogen is used as a carrier gas, titanium tetrachloride and ammonia are introduced, the gas flow rate is 350 mL / min, and a TiN layer with a thickness of 75 nm is prepared at a temperature of 900°C and a pressure of 3 kPa to form a WC@TiN core-shell structure.

[0053] Step S3, in-situ synthesis of the interfacial wetting agent (Ti, Zr, Mo)CN: consistent with step S3 in Example 2.

[0054] Step S4, wet high-energy ball milling mixing: the same as step S4 in Example 2.

[0055] Step S5, preparation of cemented carbide material: the same as step S5 in Example 2.

[0056] Comparative Example 2: A method for preparing a cemented carbide material, comprising: Step S1, tungsten carbide powder pretreatment: the same as step S1 in Example 2.

[0057] Step S2, preparing the WC@TiN core-shell structure is consistent with step S2 in Example 2.

[0058] Step S3, in situ synthesis of an interfacial wetting agent (Ti, Zr, Mo) CN: low-temperature zirconization, molybdenum layer deposition and carbonization treatment are performed in sequence to generate a (Ti, Zr, Mo) CN gradient layer; low-temperature zirconization comprises: mixing a WC@TiN core-shell structure with Y2O3 nanoparticles adsorbed on the surface with zirconium nitrate in a ratio of 1:5 of zirconium to titanium atoms, placing the mixture in a tubular furnace, heating the mixture to 600°C at a heating rate of 5°C / min with nitrogen at a nitrogen flow rate of 300 mL / min, and maintaining the mixture for 2 hours to obtain a TiN-ZrN solid solution transition layer. The molybdenum layer deposition process involved transferring the low-temperature zirconized powder into a fluidized bed reactor and heating the reactor to 300°C at a rate of 4.5°C / min using argon at a flow rate of 200 mL / min. Gaseous Mo(CO)6 was then introduced with a molybdenum to zirconium atomic ratio of 1:1 and held at this temperature for 1 hour, resulting in a 75nm thick nano-Mo layer deposited on the surface of the TiN-ZrN solid solution transition layer. The carbonization treatment involved replacing the argon atmosphere with a methane / hydrogen mixture at a volume ratio of 1:3 at a flow rate of 250 mL / min. The reactor was then heated to 800°C at a rate of 5.5°C / min and held at this temperature for 2 hours. The nano-Mo layer reacted with carbon and nitrogen, combining with the TiN-ZrN solid solution to form a (Ti, Zr, Mo)CN gradient layer.

[0059] Step S4, wet high-energy ball milling mixing: the same as step S4 in Example 2.

[0060] Step S5, preparation of cemented carbide material: the same as step S5 in Example 2.

[0061] Comparative Example 3: A method for preparing a cemented carbide material, comprising: Step S1, tungsten carbide powder pretreatment: the same as step S1 in Example 2.

[0062] Step S2, preparing a WC@TiN core-shell structure: the same as step S2 in Example 2.

[0063] Step S3, in situ synthesis of interfacial wetting agent (Ti, Zr, Mo) CN: the WC@TiN core-shell structure obtained in step S2 is uniformly mixed with Y2O3 nanopowder, so that the nanopowder is uniformly adsorbed on the surface of the core-shell structure; specifically, the WC@TiN core-shell structure and Y2O3 nanopowder are mixed in a mass ratio of 100:0.1, and anhydrous ethanol is added, and the solid-liquid ratio between anhydrous ethanol and the mixed powder is 1:4; then, the mixture is mixed in a planetary ball mill at a speed of 225 rpm for 30 minutes, so that the Y2O3 nanoparticles are uniformly adsorbed on the TiN surface of the WC@TiN core-shell structure; after mixing, the mixture is transferred to a vacuum drying oven and dried at a vacuum degree of 600 Pa and a temperature of 80°C for 2 hours.

[0064] According to the composition ratio of (Ti,Zr,Mo)CN, 0.5 mol of TiO2, 0.3 mol of ZrO2, 0.2 mol of MoO3 and 1 mol of glucose were ball-milled and mixed respectively; the ball-milled raw materials were placed in a nitrogen atmosphere with a nitrogen flow rate of 300 mL / min, heated to 900°C at a heating rate of 5°C / min, and kept warm for 2 hours to generate (Ti,Zr,Mo)CN; then, (Ti,Zr,Mo)CN was mixed with a WC@TiN core-shell structure with Y2O3 nanoparticles uniformly adsorbed on the surface in proportion to obtain a mixed powder.

[0065] Step S4, wet high-energy ball milling mixing: the same as step S4 in Example 2.

[0066] Step S5, preparation of cemented carbide material: the same as step S5 in Example 2.

[0067] Comparative Example 4: A method for preparing a cemented carbide material, comprising: Step S1, tungsten carbide powder pretreatment: the same as step S1 in Example 2.

[0068] Step S2, preparing a WC@TiN core-shell structure: the same as step S2 in Example 2.

[0069] Step S3, in-situ synthesis of the interfacial wetting agent (Ti, Zr, Mo)CN: consistent with step S3 in Example 2.

[0070] Step S4, wet high-energy ball milling mixing: wet high-energy ball milling the WC@TiN core-shell powder with the gradient layer in step S3 with a high-entropy alloy; the high-entropy alloy is AlCoCrFeNiTi; the high-entropy alloy is prepared by gas atomization, and the particle size of the high-entropy alloy powder is 1 to 5 μm.

[0071] The wet high-energy ball milling mixing is specifically as follows: the WC@TiN core-shell powder with the gradient layer is mixed with the high-entropy alloy powder in a mass percentage of 83%:17%, and anhydrous ethanol is added, and the solid-liquid ratio of anhydrous ethanol to the mixed powder is 1:3, and 0.5wt% PEG-4000 is added at the same time; the above mixed slurry is placed in a planetary ball mill, using zirconia balls with a diameter of 5mm, a ball-to-material ratio of 9:1, a rotation speed of 400rpm, and an intermittent reverse ball milling cycle of "30min forward rotation + 5min stop + 30min reverse rotation + 5min stop + 30min forward rotation" for 20h.

[0072] Step S5, preparation of cemented carbide material: the same as step S5 in Example 2.

[0073] The hardness, fracture toughness, flexural strength and wear rate of the cemented carbide materials prepared in Examples 1 to 3 and Comparative Examples 1 to 4 were tested using GB / T 4340.1-2009, GB / T 2358-1994, GB / T 38514-2020 and GB / T 34501-2017, respectively. The test results are shown in the following table:

[0074] As described above, the cemented carbide material prepared by the method of the present invention has excellent mechanical properties such as hardness, fracture toughness and flexural strength; and the cemented carbide material has finer and denser grains, a more uniform microstructure, and low internal stress. After long-term cyclic wear testing, no defects such as cracks and holes will appear due to stress.

Claims

1. A method for preparing a cemented carbide material based on a high entropy alloy bonding phase, characterized in that: include: Step S1, pretreatment of tungsten carbide powder: washing, drying and sieving the tungsten carbide powder in sequence to obtain tungsten carbide particles for standby use; Step S2, preparing a WC@TiN core-shell structure: first, the surface of the carbide particles pretreated in step S1 is pre-coated with TiO2 using a sol-gel method; then, the pre-coated TiO2 is converted into TiN through a nitriding sintering process to obtain a core-shell structure; Step S3, in-situ synthesis of an interfacial wetting agent (Ti, Zr, Mo)CN: First, the WC@TiN core-shell structure obtained in step S2 is uniformly mixed with Y2O3 nanopowder, so that the nanopowder is uniformly adsorbed on the surface of the core-shell structure; then, low-temperature zirconization, molybdenum layer deposition and carbonization treatment are sequentially performed to form a (Ti, Zr, Mo)CN gradient layer; Step S4, wet high-energy ball milling: wet high-energy ball milling the WC@TiN core-shell powder with the gradient layer in step S3 with the high-entropy alloy; Step S5, preparation of cemented carbide material: the slurry after ball milling in step S4 is subjected to vacuum freeze drying and step-by-step vacuum hot pressing sintering in sequence to obtain cemented carbide material.

2. The method for preparing a cemented carbide material based on a high entropy alloy bonding phase according to claim 1, characterized in that: In step S1, the particle size of the tungsten carbide powder is 0.2 to 5 μm; the cleaning step is specifically as follows: first, ultrasonically clean the tungsten carbide powder with a hydrochloric acid solution having a concentration of 4.5% to 5.5% for 25 to 35 minutes, and then wash it with deionized water until it is neutral; the drying step is specifically as follows: first, the washed carbide powder is placed in a vacuum drying oven, dried at a vacuum degree of 500 to 700 Pa and a temperature of 75 to 85° C. for 1.5 to 2.5 hours, and then the dried tungsten carbide powder is dispersed by passing it through a jet mill at a working pressure of 0.55 to 0.65 MPa.

3. The method for preparing a cemented carbide material based on a high entropy alloy bonding phase according to claim 1 or 2, characterized in that: The sol-gel method used in step S2 to achieve pre-coating of TiO2 is specifically as follows: first, tetrabutyl titanate is slowly dripped into anhydrous ethanol and magnetically stirred for 28 to 32 minutes to form solution A; deionized water and anhydrous ethanol are then mixed in a volume ratio of 1:1, and the pH value is adjusted to 3.5 to 4.0 with ammonia water to form solution B; thereafter, solution B is slowly dripped into solution A and continuously stirred for 1 to 1.5 hours to obtain a transparent sol; the tungsten carbide powder pretreated in step S1 is added to the transparent sol, ultrasonically dispersed, magnetically stirred, and then solvent evaporation, vacuum freeze drying and calcination are performed in sequence to obtain a tungsten carbide powder structure pre-coated with TiO2.

4. The method for preparing a cemented carbide material based on a high entropy alloy bonding phase according to claim 1 or 3, characterized in that: The tungsten carbide powder is added to the transparent sol at a solid-liquid ratio of 0.8-1.2:4.8-5.2, and ultrasonic dispersion is performed at 25-35° C. for 28-32 minutes, followed by magnetic stirring for 1.8-2.2 hours.

5. The method for preparing a cemented carbide material based on a high entropy alloy bonding phase according to claim 1 or 3, characterized in that: The solvent evaporation is specifically as follows: the mixed system after adding the transparent sol to the tungsten carbide powder is placed in a water bath at 55 to 65° C. for 2 to 3 hours to evaporate the solvent to obtain wet gel particles; the vacuum freeze drying is specifically as follows: the wet gel particles are placed in a vacuum freeze dryer and dried for 11 to 13 hours at a temperature of -55 to -45° C. and a vacuum degree of 0.8 to 1.2 Pa; the calcination is specifically as follows: the dried gel particles are heated to 480 to 520° C. at a heating rate of 4.5 to 5.5° C. / min in an air atmosphere and kept warm for 1.8 to 2.2 hours to obtain a TiO2 pre-coated tungsten carbide powder structure; wherein the thickness of the TiO2 coating layer is 50 to 100 nm.

6. The method for preparing a cemented carbide material based on a high entropy alloy bonding phase according to claim 1, characterized in that: The WC@TiN core-shell structure and the Y2O3 nanopowder are uniformly mixed in step S3 as follows: the WC@TiN core-shell structure and the Y2O3 nanopowder are mixed in a mass ratio of 99-101:0.08-0.12, and anhydrous ethanol is added, and the solid-liquid ratio between the anhydrous ethanol and the mixed powder is 0.8-1.2:3.8-4.2; then, mixing in a planetary ball mill at a speed of 200-250 rpm for 28-32 minutes, so that the Y2O3 nanoparticles are uniformly adsorbed on the TiN surface of the WC@TiN core-shell structure; after mixing, the mixture is transferred to a vacuum drying oven and dried at a vacuum degree of 500-700 Pa and a temperature of 75-85° C. for 1.8-2.2 hours.

7. The method for preparing a cemented carbide material based on a high entropy alloy bonding phase according to claim 1, characterized in that: In step S4, the high entropy alloy is AlCoCrFeNiTi a Cu b , a is 0.75-0.85, b is 0.15-0.25 and a+b=1; the high entropy alloy is prepared by a gas atomization method, and the particle size of the high entropy alloy powder is 1-5 μm.

8. The method for preparing a cemented carbide material based on a high entropy alloy bonding phase according to claim 1, characterized in that The step S4 wet high-energy ball milling mixing is specifically as follows: WC@TiN core-shell powder with a gradient layer is mixed with high-entropy alloy powder in a mass percentage of 70-97%:3-30%, and anhydrous ethanol is added, with a solid-liquid ratio of anhydrous ethanol to the mixed powder of 0.8-1.2:2.8-3.2, and 0.45-0.55wt% of PEG-4000 is added at the same time; the above mixed slurry is placed in a planetary ball mill, using zirconia balls with a diameter of 5 mm, a ball-to-material ratio of 8-10:1, a rotation speed of 350-450 rpm, and an intermittent reverse ball milling cycle of "30 minutes forward rotation + 5 minutes stop + 30 minutes reverse rotation + 5 minutes stop + 30 minutes forward rotation" is adopted, and ball milling is carried out for 18-22 hours.

9. The method for preparing a cemented carbide material based on a high entropy alloy bonding phase according to claim 1, characterized in that The vacuum freeze drying in step S5 is as follows: the ball-milled slurry is transferred into a vacuum freeze dryer and dried at -52 to -48°C and a vacuum degree of 0.8 to 1.2 Pa for 10 to 12 hours.

10. The method for preparing a cemented carbide material based on a high entropy alloy bonding phase according to claim 1, characterized in that The step-by-step vacuum hot pressing sintering in step S5 is specifically as follows: -3 Pa environment, first heat the temperature to 580-620°C at a heating rate of 9-11°C / min and keep warm for 0.8-1.2h; then fill the furnace with high-purity nitrogen to 0.1MPa, heat the temperature to 1130-1170°C at a heating rate of 5-6°C / min, keep warm for 30-35min, then heat the temperature to 1260-1300°C at a heating rate of 8-10°C / min, keep warm for 15-20min, and finally heat the temperature to 1400-1440°C at a heating rate of 80-100°C / min, apply a pressure of 30-50MPa, and keep warm for 8-12min.

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