A high-strength cemented carbide, its preparation method and application

Abstract

The present invention relates to the field of materials science and technology, and specifically relates to a high-strength cemented carbide and its preparation method and application, which includes the following steps: S1: Weigh the raw materials of tungsten carbide, cobalt, tantalum carbide, niobium carbide, titanium carbide, yttrium oxide, nickel, and trace strengthening elements according to a preset weight to form a mixture A; S2: Place the mixture A in a wet ball milling device for ball milling treatment; S3: Perform drying treatment on the ball-milled slurry; S4: Perform plasma activation treatment on the dried powder; S5: Press the activated powder to form a dense green compact; S6: Perform two-stage sintering treatment on the green compact in a vacuum sintering furnace; S7: After sintering is completed, perform cooling treatment; In the present invention, by optimizing the alloy formula and innovating the preparation process, the hardness, toughness, and high-temperature resistance of the high-strength cemented carbide are improved, and at the same time, the production process is simplified, and the overall performance and application versatility of the material are enhanced.

Description

Technical Field

[0001] The present invention relates to the field of materials science and technology, and particularly to a high-strength cemented carbide and its preparation method and application. Background Art

[0002] Cemented carbide is a kind of material mainly composed of tungsten carbide, combined with other metal elements such as cobalt, titanium, etc. Because of its high hardness, high wear resistance and excellent heat resistance, it is widely used in the manufacture of cutting tools, molds and wear-resistant parts. However, with the continuous improvement of the requirements for material properties in the industrial field, the existing cemented carbide still has deficiencies in high strength, high toughness and heat resistance. Especially in high-temperature working environments, traditional cemented carbide materials are prone to cracks, deformation or failure, affecting service life and efficiency. To meet the needs of high-strength and long-life materials in modern industry, it is necessary to further improve the comprehensive properties of cemented carbide.

[0003] There are bottlenecks in the existing cemented carbide formulations in balancing hardness and toughness. When the hardness is increased, the toughness often decreases, and the high-temperature resistance is also relatively limited. In addition, the traditional cemented carbide preparation process is complex, energy-consuming, and the sintering densification degree is insufficient, resulting in uneven microstructure of the alloy material, thus restricting its application in high-stress and high-temperature environments. Therefore, there is an urgent need for an innovative alloy formulation and an optimized preparation method to solve the above problems. Summary of the Invention

[0004] Based on the above purposes, the present invention provides a high-strength cemented carbide and its preparation method and application.

[0005] A high-strength cemented carbide includes tungsten carbide, cobalt, tantalum carbide, niobium carbide, titanium carbide, yttrium oxide, nickel and trace strengthening elements; wherein the proportions of each component by mass percentage are as follows:

[0006] The proportion of tungsten carbide is 62.5% - 84.7%;

[0007] The proportion of cobalt is 6% - 12%;

[0008] The proportion of tantalum carbide is 3% - 8%;

[0009] The proportion of niobium carbide is 2% - 6%;

[0010] The proportion of titanium carbide is 3% - 6%;

[0011] The proportion of yttrium oxide is 0.3% - 1.5%;

[0012] The proportion of nickel is 0.5% - 2%;

[0013] The proportion of trace strengthening elements is 0.5% - 2%;

[0014] The trace strengthening element is aluminum, boron or vanadium.

[0015] A method for preparing a high-strength cemented carbide, comprising the following steps:

[0016] S1: Weigh tungsten carbide, cobalt, tantalum carbide, niobium carbide, titanium carbide, yttrium oxide, nickel, and raw materials of trace strengthening elements according to preset weight percentages, and uniformly mix the components to form mixture A;

[0017] S2: Place mixture A in a wet ball milling device for ball milling to form a slurry;

[0018] S3: Dry the ball-milled slurry to obtain a uniform dry powder;

[0019] S4: Perform plasma activation treatment on the dried powder to activate the surface of the powder particles;

[0020] The specific steps of S4 include:

[0021] S41: Place the dry powder obtained in S3 in a plasma activation device, and control the vacuum degree in the device at to Pa;

[0022] S42: Set the gas flow rate of the plasma, use argon or nitrogen as the working gas, and control the flow rate at 50 - 200 ml / min;

[0023] S43: Heat the powder to 400 - 600 °C, control the treatment time at 30 - 60 minutes, and perform surface treatment through the plasma to activate the surface of the powder particles;

[0024] S44: After the treatment, cool the powder to room temperature;

[0025] S5: Press the powder after activation treatment to form a dense green compact;

[0026] S6: Perform two-stage sintering treatment on the green compact in a vacuum sintering furnace;

[0027] The specific steps of S6 include:

[0028] S61: Place the green compact in a vacuum sintering furnace, set the vacuum degree at to Pa, and start the first-stage sintering treatment;

[0029] S62: During the first-stage sintering process, raise the temperature to 800 - 1000 °C, and keep the temperature for 1 - 2 hours to remove the pores in the green compact;

[0030] S63: During the second-stage sintering process, the temperature is further increased to 1450 - 1650 °C and maintained for 2 - 4 hours to achieve complete bonding between the particles;

[0031] S7: After sintering is completed, cooling treatment is carried out to finally obtain a high-strength cemented carbide material.

[0032] Optionally, the specific steps of S2 include:

[0033] S21: Ethanol or deionized water is added to mixture A as the medium for wet ball milling, and the addition amount of the medium is 1 - 3 times the total weight of mixture A;

[0034] S22: Mixture A and the ball milling medium are placed in a ball milling device, and a ball milling medium made of cemented carbide or zirconia is selected. The mass ratio of the ball milling medium to the raw materials is controlled between 5:1 and 10:1;

[0035] S23: The ball milling speed is set at 200 - 400 revolutions per minute, and the ball milling time is controlled within 10 - 20 hours;

[0036] S24: After ball milling is completed, filtration treatment is carried out to separate the ball milling medium and obtain a uniform slurry.

[0037] Optionally, the specific steps of S3 include:

[0038] S31: The slurry obtained in S2 is placed in a spray drying device, and the feeding speed is controlled at 50 - 100 milliliters per minute;

[0039] S32: The inlet air temperature of the spray drying device is set at 150 - 250 °C, and the outlet air temperature is set at 80 - 120 °C to carry out spray drying treatment on the slurry;

[0040] S33: After the drying process is completed, the dried powder is collected and sieved to control the particle size within 1 - 5 microns to obtain a uniform dried powder.

[0041] Optionally, the specific steps of S5 include:

[0042] S51: The powder after plasma activation treatment is put into a mold. The mold material is a carbide substrate, and the mold size is selected according to the final shape of the green body;

[0043] S52: Pressure is applied in a pressing device, and the pressure is controlled at 150 - 250 MPa to gradually compact the powder to form a dense green body;

[0044] S53: While maintaining the pressure, preheating treatment is carried out at room temperature to 200 °C, and the preheating time is maintained for 10 - 30 minutes;

[0045] S54: After pressing is completed, take out the green body and perform size trimming.

[0046] Optionally, the specific steps of S7 are as follows:

[0047] S71: After sintering is completed, control the temperature in the sintering furnace at 1450 - 1650 °C and slowly cool it at a rate of 10 - 20 °C per minute until the temperature drops to 800 °C.

[0048] S72: When the temperature drops to 800 °C, adjust the cooling rate to 5 - 10 °C per minute and continue to cool slowly until the temperature drops to 300 °C.

[0049] S73: After the temperature reaches 300 °C, stop heating and let it cool naturally to room temperature to complete the cooling process.

[0050] S74: After cooling to room temperature, take out and obtain the high-strength cemented carbide material.

[0051] The above-mentioned high-strength cemented carbide and the preparation method thereof are both applied to the manufacturing of cutting tools, molds, wear-resistant parts, and high-temperature components.

[0052] Advantages of the present invention:

[0053] In the present invention, by optimizing the formula of the high-strength cemented carbide and reasonably introducing tungsten carbide, cobalt, tantalum carbide, niobium carbide, titanium carbide, yttrium oxide, nickel, and trace strengthening elements (such as aluminum, boron, or vanadium), on the basis of ensuring high hardness, the toughness and high-temperature resistance of the alloy are significantly improved. By introducing innovative trace strengthening elements, the stability of the alloy in high-temperature environments is enhanced, effectively addressing problems such as material cracking and deformation at high temperatures, and extending the service life of the alloy.

[0054] In the present invention, through innovative treatments such as plasma activation and two-stage sintering, the production process is simplified, and at the same time, the densification degree of the material is effectively improved. This process not only ensures the full combination of raw material particles, improves the microstructure of the material, but also reduces the energy consumption and production cost during the sintering process, and has broad industrial application prospects. Description of the Drawings

[0055] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings described below are only those of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0056] Figure 1 Schematic diagram of the components of the high-strength cemented carbide according to the embodiment of the present invention;

[0057] Figure 2 Schematic diagram of the preparation method of the high-strength cemented carbide according to the embodiment of the present invention. Specific embodiments

[0058] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. At the same time, it should be noted here that in order to make the embodiments more detailed, the following embodiments are the best and preferred embodiments. For some well-known technologies, those skilled in the art can also adopt other alternative methods for implementation; moreover, the accompanying drawings are only for more specific description of the embodiments, and are not intended to specifically limit the present invention.

[0059] It should be noted that in the specification, the mention of "one embodiment", "embodiment", "exemplary embodiment", "some embodiments", etc. indicates that the described embodiment may include specific features, structures or characteristics, but not necessarily every embodiment includes the specific feature, structure or characteristic. In addition, when combining an embodiment to describe a specific feature, structure or characteristic, implementing such a feature, structure or characteristic in combination with other embodiments (whether explicitly described or not) should be within the knowledge of those skilled in the relevant art.

[0060] Generally, the terms can be understood at least in part from their use in the context. For example, at least in part depending on the context, the term "one or more" used herein can be used to describe any feature, structure or characteristic in a singular sense, or can be used to describe a combination of features, structures or characteristics in a plural sense. In addition, the term "based on" can be understood as not necessarily intended to convey a set of exclusive factors, but instead, at least in part depending on the context, allowing for the existence of other factors that may not be explicitly described.

[0061] Embodiment 1

[0062] As Figure 1 shown, a high-strength cemented carbide includes tungsten carbide, cobalt, tantalum carbide, niobium carbide, titanium carbide, yttrium oxide, nickel and trace strengthening elements; wherein the components are in mass percentages as follows,

[0063] Tungsten carbide accounts for 72%;

[0064] Cobalt accounts for 10%;

[0065] Tantalum carbide accounts for 6%;

[0066] Niobium carbide accounts for 4%;

[0067] Titanium carbide accounts for 4%;

[0068] Yttrium oxide accounts for 1%;

[0069] Nickel accounts for 1.5%;

[0070] Trace fortified elements account for 1.5%.

[0071] The trace strengthening element is aluminum.

[0072] like Figure 2 As shown, a method for preparing a high-strength cemented carbide comprises the following steps:

[0073] S1: weighing raw materials of tungsten carbide, cobalt, tantalum carbide, niobium carbide, titanium carbide, yttrium oxide, nickel, and trace strengthening elements according to preset weight percentages, and uniformly mixing the components to form a mixture A;

[0074] S2: placing the mixture A in a wet ball mill for ball milling to form a slurry, thereby providing a suitable powder morphology for subsequent densification and sintering;

[0075] S3: Drying the ball-milled slurry to obtain uniform dry powder, ensuring that the powder is easy to press and form in subsequent steps;

[0076] S4: Plasma activation treatment is performed on the dried powder to activate the surface of the powder particles. The surface activity of the powder particles is enhanced through the surface energy excitation of the plasma, thereby promoting densification in the subsequent sintering process;

[0077] S5: pressing the activated powder to form a dense green body;

[0078] S6: performing a two-stage sintering process on the green body in a vacuum sintering furnace, wherein the first stage is used to eliminate internal pores, and the second stage is used to achieve densification of the green body;

[0079] S7: After sintering is completed, cooling treatment is performed to finally obtain a high-strength cemented carbide material.

[0080] S2 specifically includes:

[0081] S21: adding deionized water to the mixture A as a medium for wet ball milling, and the amount of the medium added is twice the total weight of the mixture A;

[0082] S22: placing the mixture A and the ball milling medium in a ball milling device, selecting the ball milling medium made of cemented carbide, and controlling the mass ratio of the ball milling medium to the raw material to be 7:1;

[0083] S23: setting the ball milling speed to 300 rpm and the ball milling time to 15 hours to ensure that the raw material particles are evenly mixed and refined;

[0084] S24: After the ball milling is completed, filtering is performed to separate the ball milling medium to obtain a uniform slurry.

[0085] S3 specifically includes:

[0086] S31: Place the slurry obtained in S2 into a spray drying device, and control the feeding speed at 80 milliliters per minute;

[0087] S32: Set the inlet air temperature of the spray drying device at 200 °C and the outlet air temperature at 100 °C, and conduct spray drying treatment on the slurry;

[0088] S33: After the drying process ends, collect the dried powder, and through screening treatment, control the particle size at 3 micrometers to obtain uniform dried powder.

[0089] S4 specifically includes:

[0090] S41: Place the dried powder obtained in S3 into a plasma activation device, and control the vacuum degree inside the device at Pa;

[0091] S42: Set the gas flow rate of the plasma, use argon as the working gas, and control the flow rate at 100 milliliters per minute;

[0092] S43: Heat the powder to 500 °C, control the treatment time at 45 minutes, and conduct surface treatment through the plasma to activate the surface of the powder particles;

[0093] S44: After the treatment ends, cool the powder to room temperature for standby for the next step.

[0094] S5 specifically includes:

[0095] S51: Put the powder after plasma activation treatment into a mold. The mold material is a carbide substrate, and the mold size is selected according to the final shape of the green body;

[0096] S52: Apply pressure in a pressing device, control the pressure at 200 MPa, and gradually compact the powder to form a dense green body;

[0097] S53: While maintaining the pressure, apply preheating treatment from room temperature to 200 °C, and keep the preheating time at 20 minutes to ensure the tight combination between the powder particles;

[0098] S54: After the pressing is completed, take out the green body and perform size trimming to ensure that the size and shape of the green body meet the requirements for standby for sintering in the next step.

[0099] S6 specifically includes:

[0100] S61: Put the green body into a vacuum sintering furnace, set the vacuum degree at Pa, and start the first-stage sintering treatment;

[0101] S62: During the first-stage sintering process, the temperature is raised to 900 °C and held for 1.5 hours to remove the pores in the green body and enhance the preliminary densification of the material.

[0102] S63: During the second-stage sintering process, the temperature is further raised to 1550 °C and maintained for 3 hours to further densify the green body and achieve complete bonding between the particles.

[0103] S7 specifically includes:

[0104] S71: After sintering is completed, the temperature in the sintering furnace is controlled at 1550 °C and slowly cooled at a rate of 15 °C per minute until the temperature drops to 800 °C.

[0105] S72: When the temperature drops to 800 °C, the cooling rate is adjusted to 7 °C per minute and continues to be slowly cooled until the temperature drops to 300 °C.

[0106] S73: After the temperature reaches 300 °C, heating is stopped and it is naturally cooled to room temperature to complete the cooling process.

[0107] S74: After cooling to room temperature, it is taken out to obtain a high-strength cemented carbide material, and appearance inspection and size trimming are carried out to ensure that the alloy material meets the predetermined specification requirements.

[0108] The above-mentioned high-strength cemented carbide and the preparation method of the above-mentioned high-strength cemented carbide are both applied to the manufacturing of cutting tools, molds, wear-resistant parts and high-temperature components.

[0109] Example 2

[0110] Material ratio: tungsten carbide 84.7%; cobalt 6%; tantalum carbide 3%; niobium carbide 2%; titanium carbide 3%; yttrium oxide 0.3%; nickel 0.5%; trace strengthening element (boron): 0.5%.

[0111] The preparation steps are as follows:

[0112] S1: Weigh tungsten carbide, cobalt, tantalum carbide, niobium carbide, titanium carbide, yttrium oxide, nickel and trace strengthening element aluminum according to the above ratio, and fully mix each component to obtain mixture A.

[0113] S2: Add ethanol to mixture A, and the addition amount is 1 time the mass of mixture A. Use zirconia as the ball-milling medium, and the mass ratio of the ball-milling medium to the raw materials is 5:1. Set the ball-milling speed to 200 revolutions per minute and the ball-milling time to 10 hours. After ball-milling, filter the slurry to obtain a uniform slurry.

[0114] S3: Feed the slurry into the spray drying equipment at a feeding rate of 50 ml / minute, set the inlet air temperature at 150 °C and the outlet air temperature at 80 °C, conduct spray drying, and control the particle size of the dried powder within 1 micron;

[0115] S4: Place the dried powder in a plasma activation equipment with a vacuum degree of Pa, use nitrogen as the working gas, control the gas flow rate at 50 ml / minute, heat the powder to 400 °C, with a treatment time of 30 minutes. After the treatment, cool the powder to room temperature;

[0116] S5: Put the powder after activation treatment into the mold of the carbide substrate, apply a pressure of 150 MPa, and conduct preheating at room temperature for 10 minutes to press into a dense green compact;

[0117] S6: Place the green compact in a vacuum sintering furnace with a vacuum degree of Pa for sintering; the first-stage sintering temperature is 800 °C, with a heat preservation time of 1 hour; the second-stage sintering temperature is 1450 °C, with a heat preservation time of 2 hours to complete the bonding between particles;

[0118] S7: After sintering is completed, reduce the temperature to 800 °C at a rate of 10 °C / minute, then continue to reduce the temperature to 300 °C at a rate of 5 °C / minute, and finally cool naturally to room temperature to obtain a high-strength cemented carbide material.

[0119] Example 3

[0120] Material ratio: tungsten carbide 62.5%; cobalt 12%; tantalum carbide 8%; niobium carbide 6%; titanium carbide 6%; yttrium oxide 1.5%; nickel 2%; trace strengthening element (vanadium): 2%.

[0121] The preparation steps are as follows:

[0122] S1: Weigh tungsten carbide, cobalt, tantalum carbide, niobium carbide, titanium carbide, yttrium oxide, nickel and trace strengthening element aluminum according to the above ratio, and fully mix each component to obtain mixture A;

[0123] S2: Add deionized water to mixture A, with the addition amount being 3 times the mass of mixture A. Use a cemented carbide material as the ball milling medium, with the mass ratio of the ball milling medium to the raw materials being 10:1, and set the ball milling speed at 400 revolutions per minute and the ball milling time at 20 hours. After the ball milling is completed, filter the slurry to obtain a uniform slurry;

[0124] S3: Feed the slurry into the spray drying equipment at a feeding rate of 100 ml / minute, set the inlet air temperature at 250 °C and the outlet air temperature at 120 °C, conduct spray drying, and control the particle size of the dried powder within 5 microns;

[0125] S4: Place the dried powder in a plasma activation device with a vacuum degree of Pa, use argon as the working gas, control the gas flow rate at 200 ml / min, heat the powder to 600 °C, keep the treatment time for 60 minutes, and after the treatment, cool the powder to room temperature;

[0126] S5: Put the activated powder into a carbide substrate mold, apply a pressure of 250 MPa, and preheat it at room temperature for 30 minutes to press a dense green body;

[0127] S6: Place the green body in a vacuum sintering furnace with a vacuum degree of Pa for sintering; the first-stage sintering temperature is 1000 °C and keep it for 2 hours; the second-stage sintering temperature is 1650 °C and keep it for 4 hours to complete the bonding between particles;

[0128] S7: After sintering, reduce the temperature to 800 °C at a rate of 20 °C / min, then continue to reduce the temperature to 300 °C at a rate of 10 °C / min, and finally cool it naturally to room temperature to obtain a high-strength cemented carbide material.

[0129] Table 1 Performance comparison of high-strength cemented carbide material products

[0130]

[0131] From the above Table 1, the following conclusions can be drawn through comparison. The hardness of Example 1 is the highest, reaching 2100 HV, which is better than the other two examples, showing the strong anti-deformation ability of this alloy; the flexural strength of Example 1 is the highest, reaching 3200 MPa, indicating that the alloy performs excellently under bending load; the density of Example 2 is the largest. Although the high density may affect other physical properties such as toughness and machinability; the compressive strength of Example 1 is the highest, showing excellent load-bearing capacity under compressive load; the wear rate of Example 1 is the lowest, indicating its best wear resistance and being suitable for high-wear environments; the toughness of Example 1 is the highest, combining an excellent balance of hardness and impact resistance; the sintering shrinkage rate of Example 1 is the lowest, showing high dimensional stability. Based on the above data, Example 1 performs best in terms of hardness, flexural strength, compressive strength, wear resistance and toughness, etc., and has the optimal comprehensive performance.

[0132] Table 2 Performance comparison in other aspects

[0133]

[0134] As can be seen from Table 2 above, the thermal conductivity of Example 1 is 80 W / m·K, indicating its high thermal conductivity and suitability for heat dissipation requirements in high-temperature environments; the coefficient of thermal expansion of Example 1 is low, at 5.2, indicating stronger dimensional stability of the alloy when the temperature changes; the corrosion rate of Example 1 is the lowest, only 0.02%, showing very excellent corrosion resistance; the high-temperature oxidation stability of Example 1 is the best, with an oxidation rate of only 0.15% at high temperatures, and it can maintain good chemical stability at high temperatures; the impact resistance of Example 1 is 2.5 MJ / m², superior to other examples, and has better impact absorption capacity; the fracture toughness of Example 1 is the highest, at 10 MPa·m^0.5, showing good fracture resistance; the machining performance of Example 1 is the best, with a cutting speed of up to 200 m / min, meaning that the alloy is more efficient during the machining process. In summary, Example 1 has obvious advantages in terms of thermal conductivity, corrosion resistance, oxidation stability, impact resistance, fracture toughness, and machinability, etc., so it can be determined as the best example.

[0135] This invention covers any substitutions, modifications, equivalent methods, and solutions made to the essence and scope of this invention. For the public to have a thorough understanding of this invention, specific details are described in detail in the following preferred embodiments of this invention. However, those skilled in the art can fully understand this invention even without the description of these details. Additionally, well-known methods, processes, procedures, components, and circuits, etc. are not described in detail to avoid unnecessary confusion to the essence of this invention.

[0136] The above description is only a preferred embodiment of this invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of this invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of this invention.

Claims

1. A method for preparing high-strength cemented carbide, characterized in that, The high-strength cemented carbide includes tungsten carbide, cobalt, tantalum carbide, niobium carbide, titanium carbide, yttrium oxide, nickel, and trace strengthening elements; wherein the proportions of each component by mass percentage are: Tungsten carbide accounts for 72%; Cobalt accounts for 10%; Tantalum carbide accounts for 6%; Niobium carbide accounts for 4%; Titanium carbide accounts for 4%; Yttrium oxide accounts for 1%; Nickel accounts for 1.5%; Trace strengthening elements account for 1.5%; The trace strengthening element is aluminum; The method for preparing high-strength cemented carbide includes the following steps: S1: Weigh the raw materials of tungsten carbide, cobalt, tantalum carbide, niobium carbide, titanium carbide, yttrium oxide, nickel, and trace strengthening elements according to the preset weight percentages, and uniformly mix each component to form mixture A; S2: Place mixture A in a wet ball milling device for ball milling to form a slurry, so as to provide a suitable powder form for subsequent densification and sintering; S3: Dry the ball-milled slurry to obtain uniform dry powder, ensuring that the powder is easy to press into shape in subsequent steps; S4: Perform plasma activation treatment on the dried powder to activate the surface of the powder particles. Through the surface energy excitation of the plasma, the surface activity of the powder particles is enhanced, promoting densification during subsequent sintering; S5: Press the activated powder to form a dense green compact; S6: Perform two-stage sintering treatment on the green compact in a vacuum sintering furnace. The first stage is used to remove internal pores, and the second stage realizes the densification of the green compact; S7: After sintering is completed, perform a cooling treatment to finally obtain a high-strength cemented carbide material; The prepared high-strength cemented carbide material has a hardness of 2100 HV, a transverse rupture strength of 3200 MPa, and a density of 14.5 g / cm 3 ; the compressive strength is 4600 MPa, the wear rate is 0.2%, and the toughness is 10 J / cm 2 ; The sintering shrinkage rate is 12%; the thermal conductivity is 80 W / m·K, and the thermal expansion coefficient is 5.2 (10^ -6 / K); the minimum corrosion rate is 0.02%; the oxidation rate at high temperature is 0.15%; the impact resistance is 2.5 MJ / m²; the fracture toughness is 10 MPa·m^0.5; the cutting speed is 200 m / min.

2. The method for preparing high-strength cemented carbide according to claim 1, and the prepared high-strength cemented carbide is applied to the manufacture of cutting tools, molds, wear-resistant parts, and high-temperature components.

3. A method for preparing a high-strength cemented carbide according to claim 1, characterized in that, S2 specifically includes: S21: Add deionized water to mixture A as the medium for wet ball milling, and the addition amount of the medium is 2 times the total weight of mixture A; S22: Place mixture A and the ball milling medium in a ball milling device, select a ball milling medium made of cemented carbide, and control the mass ratio of the ball milling medium to the raw materials at 7:1; S23: Set the ball milling speed at 300 revolutions per minute, and control the ball milling time within 15 hours to ensure uniform mixing and refinement of the raw material particles; S24: After ball milling is completed, perform a filtration treatment to separate the ball milling medium and obtain a uniform slurry.

4. The method for preparing high-strength cemented carbide according to claim 1, characterized in that, S3 specifically includes: S31: Place the slurry obtained in S2 in a spray drying device, and control the feeding speed at 80 milliliters per minute; S32: Set the inlet air temperature of the spray drying device at 200 °C and the outlet air temperature at 100 °C, and perform spray drying treatment on the slurry; S33: After the drying process is completed, collect the dried powder and, through screening treatment, control the particle size within 3 microns to obtain uniform dry powder.

5. The method for preparing high-strength cemented carbide according to claim 1, characterized in that, S4 specifically includes: S41: Place the dried powder obtained in S3 into a plasma activation device, and control the vacuum degree inside the device at 10-4 Pa; S42: Set the gas flow rate of the plasma. Use argon as the working gas, and control the flow rate at 100 ml / min; S43: Heat the powder to 500 °C, control the treatment time at 45 minutes, and perform surface treatment through plasma to activate the surface of the powder particles; S44: After the treatment, cool the powder to room temperature and reserve it for the next step.

6. A method for preparing a high-strength cemented carbide according to claim 1, characterized in that S5 specifically includes: S51: Put the powder after plasma activation treatment into a mold. The mold material is a carbide substrate, and the mold size is selected according to the final shape of the green body; S52: Apply pressure in a pressing device, control the pressure at 200 MPa, and gradually compress the powder to form a dense green body; S53: While maintaining the pressure, apply a preheating treatment from room temperature to 200 °C, and keep the preheating time at 20 minutes to ensure the tight combination between the powder particles; S54: After pressing is completed, take out the green body and perform size trimming to ensure that the size and shape of the green body meet the requirements, and reserve it for sintering in the next step.

7. A method for preparing a high-strength cemented carbide according to claim 1, characterized in that S6 specifically includes: S61: Put the green body into a vacuum sintering furnace, set the vacuum degree at 10-4 Pa, and start the first-stage sintering treatment; S62: During the first-stage sintering process, raise the temperature to 900 °C and keep the temperature for 1.5 hours to remove the pores in the green body and enhance the initial densification of the material; S63: During the second-stage sintering process, continue to raise the temperature to 1550 °C and keep it for 3 hours to further densify the green body and achieve complete bonding between the particles.

8. A method for preparing a high-strength cemented carbide according to claim 1, characterized in that S7 specifically includes: S71: After sintering is completed, control the temperature in the sintering furnace at 1550 °C, and slowly cool it at a rate of 15 °C / min until the temperature drops to 800 °C; S72: When the temperature drops to 800 °C, adjust the cooling rate to 7 °C / min and continue to cool slowly until the temperature drops to 300 °C; S73: After the temperature reaches 300 °C, stop heating and naturally cool it to room temperature to complete the cooling treatment; S74: After cooling to room temperature, take out and obtain the high-strength cemented carbide material, and perform appearance inspection and size trimming to ensure that the alloy material meets the predetermined specification requirements.

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