High-entropy cemented carbide and method for manufacturing the same

Abstract

The application discloses a high-entropy hard alloy, and relates to the technical field of ceramics. The high-entropy hard alloy comprises 80-100% of a hard phase and 0-20% of a binder phase, wherein the total mass of the high-entropy hard alloy is taken as 100%; the hard phase is a high-entropy carbide ceramic; the preparation raw materials of the high-entropy carbide ceramic comprise three or more than three of WC, TiC, Mo2C, NbC, TaC, VC, Cr2C3 and HfC; the preparation raw materials of the high-entropy carbide ceramic comprise 0-70% of WC, 5-60% of TiC, 0-20% of Mo2C, 0-30% of NbC, 0-45% of TaC, 0-30% of VC, 0-20% of Cr2C3 and 0-30% of HfC, with the total mass of the high-entropy hard alloy taken as 100%; the binder phase is an alloy; the preparation raw materials of the alloy comprise two or more than two of Co, Ni and Cu; the preparation raw materials of the alloy comprise 0-15% of Co, 0-15% of Ni and 0-10% of Cu, with the total mass of the high-entropy hard alloy taken as 100%. The high-entropy hard alloy provided by the technical scheme has high compactness, high hardness and high fracture toughness.

Description

Technical Field

[0001] This invention relates to the field of ceramic technology, and more specifically, to a high-entropy cemented carbide and its preparation method. Background Technology

[0002] With technological advancements and increasingly complex application environments, traditional cemented carbide materials are no longer sufficient to meet the demands of demanding working conditions. There is an urgent need to develop hard materials with high wear resistance, high strength, and high toughness. Compared to single carbide ceramics, high-entropy carbide ceramics exhibit higher hardness, strength, and thermal stability due to the high-entropy effect, solid solution strengthening, hysteresis diffusion effect, and cocktail effect. They also possess better strength and wear resistance, making them a crucial future direction for hard materials. However, despite their high wear resistance and strength, the currently prepared bulk high-entropy carbide ceramics still face technical challenges related to low density and low fracture toughness, limiting their application in practical production and daily life.

[0003] In summary, based on the applicant's extensive research, it has been found that high-entropy cemented carbides cannot simultaneously possess high density, high hardness, and high fracture toughness. Therefore, it is necessary to develop or improve a high-entropy cemented carbide and its preparation method. Summary of the Invention

[0004] Therefore, in order to solve the problem that high-entropy cemented carbide cannot simultaneously possess high density, high hardness, and high fracture toughness, this invention provides a high-entropy cemented carbide and its preparation method, the specific technical solution of which is as follows:

[0005] A high-entropy cemented carbide, comprising 80-100% hard phase and 0-20% binder phase by weight of the total mass of the high-entropy cemented carbide;

[0006] The hard phase is a high-entropy carbide ceramic; the raw materials for preparing the high-entropy carbide ceramic include three or more of WC, TiC, Mo2C, NbC, TaC, VC, Cr2C3 and HfC.

[0007] The raw materials for preparing the high-entropy carbide ceramic, based on the total mass of the high-entropy cemented carbide as 100%, include 0-70% WC, 5-60% TiC, 0-20% Mo2C, 0-30% NbC, 0-45% TaC, 0-30% VC, 0-20% Cr2C3, and 0-30% HfC.

[0008] The binder phase is an alloy; the raw materials for preparing the alloy include two or more of Co, Ni and Cu;

[0009] The raw materials for preparing the high-entropy cemented carbide, based on the total mass of the high-entropy cemented carbide, include 0-15% Co, 0-15% Ni and 0-10% Cu.

[0010] Furthermore, the powder particle size of WC, TiC, Mo2C, NbC, TaC, VC, Cr2C3 and HfC is 0.05-5 μm, and the powder purity is 98-100 wt%.

[0011] The Co, Ni, and Cu powders have a particle size of 0.5–5 μm and a purity of 98–100 wt%.

[0012] This technical solution also provides a method for preparing high-entropy cemented carbide, which includes the following steps:

[0013] Step S1: Weigh the raw materials for preparing high-entropy carbide ceramics according to the mass ratio, put the raw materials, grinding media and grinding balls into the ball mill jar, then purge with inert gas, perform ball milling once, dry the slurry, crush and sieve the powder to obtain high-entropy carbide ceramic powder;

[0014] Step S2: The high-entropy carbide ceramic powder is cold-pressed into shape, then placed in a vacuum furnace for heat treatment, and after cooling in the furnace, it is crushed and sieved to obtain high-entropy carbide ceramic.

[0015] Step S3: Place the raw materials for preparing the high-entropy carbide ceramics and alloys, grinding media and grinding balls into a ball mill jar, then purge with inert gas, perform secondary ball milling, dry the slurry, crush and sieve the powder to obtain high-entropy cemented carbide powder.

[0016] Step S4: The high-entropy cemented carbide powder is loaded into a mold and pressed into shape, and then vacuum sintered using vacuum sintering technology to obtain the high-entropy cemented carbide.

[0017] Furthermore, the raw materials for preparing the high-entropy carbide ceramic are three or more different types of carbides, and the metal element ratio of the different types of carbides is not an equimolar ratio.

[0018] Furthermore, the grinding medium is one or more of anhydrous ethanol, acetone, ethane, and gasoline.

[0019] Furthermore, the grinding balls are tungsten carbide grinding balls, and the grinding jar is a stainless steel grinding jar.

[0020] Further, in step S1, the conditions for the first ball milling are: ball milling speed 50-450 r / min, ball milling time 10-400 h, and ball-to-powder ratio 3-10:1.

[0021] Furthermore, in step S2, the cold pressing conditions are: cold pressing pressure 30-100 MPa;

[0022] The heat treatment conditions are: holding at 1000-2000℃ for 20-180 minutes.

[0023] Furthermore, in step S3, the conditions for the secondary ball milling are: a ball milling speed of 50-150 r / min, a ball milling time of 5-30 h, and a ball-to-powder ratio of 2-5:1.

[0024] Further, in step S4, the vacuum sintering conditions are: heating to 1300-2000℃ at a rate of 3-20℃ / min, and holding at that temperature for 30-200min.

[0025] Compared with the prior art, the beneficial effects of the present invention are:

[0026] (1) A two-stage ball milling process is adopted. The first stage ball milling process is a high-energy ball milling process. Through long-term, high-speed high-energy ball milling, the mechanical alloying of carbide powder is achieved to form high-entropy carbide powder with a single solid solution. High-energy ball milling reduces the powder particle size and increases the surface energy of the system. At the same time, the mechanical collisions generated by high-energy ball milling introduce a large amount of strain into the powder, dislocation multiplication, defects, and lattice distortion, thereby obtaining additional lattice distortion energy. The increase in lattice distortion energy and surface energy together increases the total energy of the system, activates the powder, and reduces the sintering temperature. The second stage ball milling is a mixed ball milling process. The binder Co and Ni are mixed with the high-entropy carbide ceramic powder to achieve uniform component distribution and avoid powder agglomeration and element aggregation, which would cause uneven distribution of the binder phase and form defects after sintering. The addition of metal powder in the later stage process can effectively reduce the oxidation degree of the metal powder and avoid the introduction of oxide impurities by long-term ball milling.

[0027] (2) A high-entropy carbide ceramic pre-preparation process using cold pressing and heat treatment is adopted, which allows the elements in the carbide powder to diffuse sufficiently during pre-preparation, forming a stable single solid solution. Compared with the single sintering process, since the elements in the carbide powder have already diffused sufficiently in the pre-preparation process, the element diffusion in the prepared high-entropy cemented carbide is more complete, and the comprehensive mechanical properties of the high-entropy cemented carbide are improved. The pre-preparation method can appropriately reduce the holding time and sintering temperature of the subsequent sintering process, avoiding excessive grain growth during sintering, which would cause coarse grains and a decrease in material strength. This method can produce fine-grained high-entropy cemented carbide with higher comprehensive mechanical properties.

[0028] (3) Using carbide grinding balls and stainless steel grinding jars can avoid introducing impurity elements. The addition of grinding media can better disperse the powder and avoid powder agglomeration. The lower heating rate and appropriate holding time ensure sufficient diffusion between elements during sintering, promoting the formation of a stable single solid solution. Compared with single elements as binders, Co powder and Ni powder as binder phases can better wet high-entropy carbides, improve the density of the material, reduce porosity, and improve the toughness of the material. In addition, the solid solubility between elements such as W, Ti, Mo, Nb, Ta, V, Cr, Co, Ni, and Cu is good, which is conducive to the formation of a single solid solution.

[0029] (4) Utilizing the high hardness, high strength, and high wear resistance of high-entropy carbides, they are used as the hard phase to replace the traditional hard phases WC, TiC, and Ti(C,N), thereby improving the strength and hardness of the material. Alloys prepared with Co, Ni, and Cu are used as binders to solve the technical challenges of poor density and fracture toughness of high-entropy carbides. The high-entropy cemented carbide obtained through this method possesses high hardness, high wear resistance, and high fracture toughness, making it a hard material with excellent comprehensive mechanical properties.

[0030] The high-entropy carbide ceramic prepared by this invention has high density and high fracture toughness while maintaining high hardness and high strength. It is a new type of hard material with excellent comprehensive mechanical properties. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to its embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the scope of protection of the invention.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0033] One embodiment of the present invention provides a high-entropy cemented carbide, which, based on the total mass of the high-entropy cemented carbide, comprises 80-100% hard phase and 0-20% binder phase.

[0034] The hard phase is a high-entropy carbide ceramic; the raw materials for preparing the high-entropy carbide ceramic include three or more of WC, TiC, Mo2C, NbC, TaC, VC, Cr2C3 and HfC (hafnium carbide);

[0035] The raw materials for preparing the high-entropy carbide ceramic, based on the total mass of the high-entropy cemented carbide as 100%, include 0-45% TaC, 5-60% TiC, 0-20% Mo2C, 0-30% NbC, 0-70% WC, 0-30% VC, 0-20% Cr2C3, and 0-30% HfC.

[0036] The binder phase is an alloy; the raw materials for preparing the alloy include two or more of Co, Ni and Cu;

[0037] The raw materials for preparing the high-entropy cemented carbide, based on the total mass of the high-entropy cemented carbide, include 0-15% Co, 0-15% Ni and 0-10% Cu.

[0038] Preferably, the raw materials for preparing the high-entropy carbide ceramic, based on the total mass of the high-entropy cemented carbide, include 0-70% WC, 10-55% TiC, 0-20% Mo2C, 0-30% NbC, 0-45% TaC, 0-30% VC, 0-20% Cr2C3, and 0-30% HfC.

[0039] In one embodiment, the powder particle size of WC, TiC, Mo2C, NbC, TaC, VC, Cr2C3 and HfC is 0.05 to 5 μm, and the powder purity is 98 to 100 wt%.

[0040] The Co, Ni, and Cu powders have a particle size of 0.5–5 μm and a purity of 98–100 wt%.

[0041] Preferably, the powder particles of WC, TiC, Mo2C, NbC, TaC, VC, Cr2C3 and HfC have a particle size of 0.05 to 2 μm and a purity of 98 to 100 wt%.

[0042] The Co, Ni, and Cu powders have a particle size of 0.5–5 μm and a purity of 98–100 wt%.

[0043] More preferably, the powder particles of WC, TiC, Mo2C, NbC, TaC, VC, Cr2C3 and HfC have a particle size of 0.05 to 2 μm and a purity of 98 to 100 wt%.

[0044] The Co, Ni and Cu powders have a particle size of 0.5–2 μm and a purity of 98–100 wt%.

[0045] In one embodiment, the present technical solution also provides a method for preparing a high-entropy cemented carbide, which includes the following steps:

[0046] Step S1: Weigh the raw materials for preparing high-entropy carbide ceramics according to the mass ratio, put the raw materials, grinding media and grinding balls into the ball mill jar, then purge with inert gas, perform ball milling once, dry the slurry, crush and sieve the powder to obtain high-entropy carbide ceramic powder;

[0047] Step S2: The high-entropy carbide ceramic powder is cold-pressed into shape, then placed in a vacuum furnace for heat treatment, and after cooling in the furnace, it is crushed and sieved to obtain high-entropy carbide ceramic.

[0048] Step S3: Place the raw materials for preparing the high-entropy carbide ceramics and alloys, grinding media and grinding balls into a ball mill jar, then purge with inert gas, perform secondary ball milling, dry the slurry, crush and sieve the powder to obtain high-entropy cemented carbide powder.

[0049] Step S4: The high-entropy cemented carbide powder is loaded into a mold and pressed into shape, and then vacuum sintered using vacuum sintering technology to obtain the high-entropy cemented carbide.

[0050] In one embodiment, the raw materials for preparing the high-entropy carbide ceramic are three or more different types of carbides, and the metal element ratio of the different types of carbides is not an equimolar ratio.

[0051] In one embodiment, the grinding medium is one or more of anhydrous ethanol, acetone, ethane, and gasoline.

[0052] In one embodiment, the grinding balls are tungsten carbide grinding balls, and the grinding jar is a stainless steel grinding jar.

[0053] In one embodiment, in step S1, the conditions for the first ball milling are: ball milling speed 50–450 r / min, ball milling time 10–400 h, and ball-to-powder ratio 3–10:1. Preferably, the ball milling speed is 100–350 r / min, the ball milling time is 10–400 h, and the ball-to-powder ratio is 3–10:1. More preferably, the ball milling speed is 120–330 r / min, the ball milling time is 10–400 h, and the ball-to-powder ratio is 3–10:1.

[0054] In one embodiment, in step S2, the cold pressing conditions are: cold pressing pressure 30-100 MPa;

[0055] The heat treatment conditions are: holding at 1000-2000℃ for 20-180 minutes.

[0056] Preferably, the cold pressing conditions are: cold pressing pressure 35-95 MPa;

[0057] The heat treatment conditions are: holding at 1000-2000℃ for 20-180 minutes.

[0058] More preferably, the cold pressing conditions are: cold pressing pressure 35-95 MPa;

[0059] The heat treatment conditions are: holding at 1100–1900℃ for 20–180 min.

[0060] In one embodiment, the conditions for the secondary ball milling in step S3 are: a ball milling speed of 50-150 r / min, a ball milling time of 5-30 h, and a ball-to-powder ratio of 2-5:1.

[0061] Preferably, the conditions for the secondary ball milling are: a ball milling speed of 50-150 r / min, a ball milling time of 5-25 h, and a ball-to-powder ratio of 2-5:1.

[0062] In one embodiment, the vacuum sintering conditions in step S4 are: heating to 1300-2000°C at a rate of 3-20°C / min and holding at that temperature for 30-200 min.

[0063] Preferably, the vacuum sintering conditions are: heating to 1300-2000℃ at a rate of 5-20℃ / min and holding at that temperature for 30-200min.

[0064] More preferably, the vacuum sintering conditions are: heating to 1300-1900℃ at a rate of 5-20℃ / min, and holding at that temperature for 30-200min.

[0065] The implementation schemes of the present invention will now be described in detail with reference to specific embodiments.

[0066] Example 1:

[0067] Weigh out 520g of TiC powder, 200g of TaC powder, and 200g of VC powder, the raw materials for preparing high-entropy carbide ceramics, with a powder particle size of 0.2–1.5 μm. Place the powder and anhydrous ethanol into a ball mill jar, add tungsten carbide grinding balls at a ball-to-powder ratio of 5:1, and ball mill at 150 r / min for 100 h. Dry the slurry, crush and sieve the powder to obtain high-entropy carbide powder. Cold press the high-entropy carbide powder at 65 MPa, place it in a vacuum furnace, hold it at 1500℃ for 100 min, cool it with the furnace, and then crush and sieve it to obtain high-entropy carbon. High-entropy carbide ceramic powder; 40g of Co powder and 40g of Ni powder with a particle size of 0.5-2μm were placed in a ball mill jar with anhydrous ethanol. Tungsten carbide grinding balls were added at a ball-to-powder ratio of 3:1, and the mixture was ball-milled for 10 hours at 50 r / min. The slurry was dried, crushed, and sieved to obtain high-entropy cemented carbide powder. The high-entropy cemented carbide powder was then pressed into shape in a mold and vacuum sintered at a heating rate of 10℃ / min at 1450℃ for 180 min to obtain high-entropy cemented carbide. The high-entropy cemented carbide had a density of 99.12%, a hardness of 15.49 GPa, and a fracture toughness of 14.4 MPa·m. 1 / 2 .

[0068] Example 2:

[0069] Weigh out 300g of WC powder, 200g of NbC powder, 150g of TaC powder, 150g of Cr2C3 powder, and 100g of TiC powder, the raw materials for preparing high-entropy carbide ceramics. The powder particle size is 0.2-1.5μm. Place the powder and anhydrous ethanol into a ball mill jar, add tungsten carbide grinding balls at a ball-to-powder ratio of 8:1, and ball mill at 200r / min for 80h. Dry the slurry, crush and sieve the powder to obtain high-entropy carbide powder. Cold press the high-entropy carbide powder into shape at 65MPa, place it in a vacuum furnace, hold it at 1500℃ for 100min, and then cool it with the furnace. High-entropy carbide ceramic powder was obtained by crushing and sieving. The high-entropy carbide ceramic powder, along with 40g of Co powder (0.5–2 μm particle size), 60g of Ni powder, and anhydrous ethanol, were placed in a ball mill jar. Tungsten carbide grinding balls were added at a ball-to-powder ratio of 5:1, and the mixture was ball-milled for 8 hours at 100 r / min. The slurry was dried, crushed, and sieved to obtain high-entropy cemented carbide powder. The high-entropy cemented carbide powder was then pressed into shape using a mold and vacuum sintered at a heating rate of 20 °C / min until it reached 1550 °C. The sintering was held at this temperature for 150 min to obtain the high-entropy cemented carbide. The high-entropy cemented carbide exhibited a density of 99.18%, a hardness of 16.54 GPa, and a fracture toughness of 14.6 MPa·m. 1 / 2 .

[0070] Example 3:

[0071] Weigh out 300g of TiC powder, 450g of TaC powder, and 130g of Mo2C powder, the raw materials for preparing high-entropy carbide ceramics. The powder particle size is 0.2-1.5μm. Place the powder and anhydrous ethanol into a ball mill jar, add tungsten carbide grinding balls at a ball-to-powder ratio of 10:1, and ball mill at 180r / min for 300h. Dry the slurry, crush and sieve the powder to obtain high-entropy carbide powder. Cold press the high-entropy carbide powder at 65MPa, place it in a vacuum furnace, hold it at 1500℃ for 100min, cool it with the furnace, and then crush and sieve the powder to obtain... High-entropy carbide ceramics were prepared by mixing high-entropy carbide ceramics with 100g of Co powder (0.5–2 μm particle size), 20g of Cu powder, and anhydrous ethanol in a ball mill jar. Tungsten carbide grinding balls were added at a ball-to-powder ratio of 3:1, and the mixture was ball-milled for 15 hours at 80 r / min. The slurry was dried, crushed, and sieved to obtain high-entropy cemented carbide powder. The powder was then pressed into shape using a mold and vacuum sintered at a heating rate of 20 °C / min until it reached 1650 °C. The high-entropy cemented carbide was held at this temperature for 100 minutes to obtain the high-entropy cemented carbide. The high-entropy cemented carbide exhibited a density of 99.56%, a hardness of 15.33 GPa, and a fracture toughness of 15.8 MPa·m. 1 / 2 .

[0072] Example 4:

[0073] Weigh out 300g of TiC powder, 450g of TaC powder, and 130g of HfC powder, the raw materials for preparing high-entropy carbide ceramics. The powder particle size is 0.2-1.5μm. Place the powder and anhydrous ethanol into a ball mill jar, add tungsten carbide grinding balls at a ball-to-powder ratio of 10:1, and ball mill at 180r / min for 300h. Dry the slurry, crush and sieve the powder to obtain high-entropy carbide powder. Cold press the high-entropy carbide powder at 65MPa, place it in a vacuum furnace, hold it at 1500℃ for 100min, cool it with the furnace, and then crush and sieve it to obtain... High-entropy carbide ceramics were prepared by mixing high-entropy carbide ceramics with 100g of Co powder (0.5–2 μm particle size), 20g of Cu powder, and anhydrous ethanol in a ball mill jar. Tungsten carbide grinding balls were added at a ball-to-powder ratio of 3:1, and the mixture was ball-milled for 15 hours at 80 r / min. The slurry was dried, crushed, and sieved to obtain high-entropy cemented carbide powder. The powder was then pressed into shape using a mold and vacuum sintered at a heating rate of 20 °C / min until it reached 1650 °C. The sintering temperature was maintained for 100 minutes to obtain the high-entropy cemented carbide. The high-entropy cemented carbide exhibited a density of 99.62%, a hardness of 16.89 GPa, and a fracture toughness of 16.1 MPa·m. 1 / 2 .

[0074] Example 5:

[0075] Weigh out 700g of WC powder, 190g of TiC powder, 20g of NbC powder, and 30g of MoC powder, the raw materials for preparing high-entropy carbide ceramics. The powder particle size is 0.1-1.0μm. Place the powder and anhydrous ethanol into a ball mill jar, add tungsten carbide grinding balls at a ball-to-powder ratio of 5:1, and ball mill at 200r / min for 50h. Dry the slurry, crush and sieve the powder to obtain high-entropy carbide powder. Cold press the high-entropy carbide powder at 65MPa, place it in a vacuum furnace, hold it at 1450℃ for 60min, cool it with the furnace, and then crush and sieve the powder to obtain... High-entropy carbide ceramics were obtained. The high-entropy carbide ceramics, along with 30g of Co powder (0.8–1.0 μm particle size), 30g of Cu powder, and anhydrous ethanol, were placed in a ball mill jar. Tungsten carbide grinding balls were added at a ball-to-powder ratio of 3:1, and the mixture was ball-milled for 9 hours at 100 r / min. The slurry was dried, crushed, and sieved to obtain high-entropy cemented carbide powder. The high-entropy cemented carbide powder was then pressed into shape using a mold and vacuum sintered at a heating rate of 10 °C / min at 1600 °C for 120 min to obtain the high-entropy cemented carbide. The high-entropy cemented carbide had a density of 99.47%, a hardness of 15.76 GPa, and a fracture toughness of 15.3 MPa·m. 1 / 2 .

[0076] Comparative Example 1:

[0077] 520g of TiC powder, 200g of TaC powder, and 200g of VC powder with a particle size of 0.2–1.5 μm were weighed out. Separately, 40g of Co powder and 40g of Ni powder with a particle size of 0.5–2 μm were weighed out. These powders were placed in a ball mill jar with anhydrous ethanol, and tungsten carbide grinding balls were added at a ball-to-powder ratio of 5:1. The mixture was ball-milled at 150 r / min for 100 h. The slurry was dried, crushed, and sieved to obtain alloy powder. The alloy powder was then pressed into shape using a mold and vacuum sintered at a heating rate of 10 °C / min at 1450 °C for 180 min to obtain the alloy. The alloy had a density of 95.03%, a hardness of 12.88 GPa, and a fracture toughness of 6.5 MPa·m. 1 / 2 .

[0078] Comparative Example 2:

[0079] Weigh out 300g of WC powder, 200g of NbC powder, 150g of TaC powder, 150g of Cr2C3 powder, and 100g of TiC powder. The powder particle size is 0.2-1.5μm. Place the powder and anhydrous ethanol into a ball mill jar, add tungsten carbide grinding balls at a ball-to-powder ratio of 8:1, and ball mill at 200r / min for 80h. Dry the slurry, crush and sieve the powder to obtain carbide ceramic powder. Cold press the carbide ceramic powder at 65MPa, place it in a vacuum furnace, hold it at 1500℃ for 100min, cool it with the furnace, crush and sieve it to obtain carbide ceramic. Press the carbide ceramic into a mold, heat it at a rate of 20℃ / min, and vacuum sinter it at 1550℃ for 150min to obtain an alloy. The alloy has a density of 97.66%, a hardness of 12.78 GPa, and a fracture toughness of 5.9 MPa·m. 1 / 2 .

[0080] Comparative Example 3:

[0081] Weigh 520g of TiC powder and 200g of TaC powder, with a particle size of 0.2–1.5μm. Place the powder and anhydrous ethanol into a ball mill jar, add tungsten carbide grinding balls at a ball-to-powder ratio of 5:1, and ball mill at 150 r / min for 100 h. Dry the slurry, crush and sieve the powder to obtain carbide ceramic powder. Cold press the carbide ceramic powder at 65 MPa, place it in a vacuum furnace, hold it at 1500℃ for 100 min, cool it with the furnace, and then crush and sieve it to obtain carbide. Ceramics; 40g of Co powder and 40g of Ni powder (particle size 0.5–2 μm) were placed in a ball mill jar with anhydrous ethanol. Tungsten carbide grinding balls were added at a ball-to-powder ratio of 3:1. The mixture was ball-milled for 10 hours at 50 r / min for a second time. The slurry was dried, crushed, and sieved to obtain alloy powder. The alloy powder was then pressed into a mold and vacuum sintered at a heating rate of 10 °C / min, holding at 1450 °C for 115 min to obtain the alloy. The alloy had a density of 96.39%, a hardness of 12.03 GPa, and a fracture toughness of 10.2 MPa·m. 1 / 2 .

[0082] Comparative Example 4:

[0083] Weigh 520g of TiC powder, 200g of TaC powder, and 200g of VC powder, with a particle size of 0.2–1.5μm. Place the powder and anhydrous ethanol into a ball mill jar, add tungsten carbide grinding balls at a ball-to-powder ratio of 5:1, and ball mill at 150 r / min for 100 h. Dry the slurry, crush and sieve the powder to obtain carbide powder. Place the carbide powder, 40g of Co powder and 40g of Ni powder with a particle size of 0.5–2μm, and anhydrous ethanol into a ball mill jar, add tungsten carbide grinding balls at a ball-to-powder ratio of 3:1, and ball mill at 50 r / min for 10 h for a second ball milling. Dry the slurry, crush and sieve the powder to obtain alloy powder. Press the alloy powder into a mold and vacuum sinter it at a heating rate of 10℃ / min. Sinter at 1450℃ and hold for 115 min to obtain the alloy. The alloy has a density of 96.32%, a hardness of 13.25 GPa, and a fracture toughness of 6.9 MPa·m. 1 / 2 .

[0084] Comparative Example 5:

[0085] Weigh 520g of TiC powder, 200g of TaC powder, and 200g of VC powder with a particle size of 0.2–1.5μm. Separately weigh 40g of Co powder and 40g of Ni powder with a particle size of 0.5–2μm. Place the above powders and anhydrous ethanol into a ball mill jar, add tungsten carbide grinding balls at a ball-to-powder ratio of 5:1, and ball mill at 150 r / min for 100 h. Dry the slurry, crush and sieve the powder to obtain carbide ceramic powder. Cold press the carbide ceramic powder at 65 MPa, place it in a vacuum furnace, hold it at 1500℃ for 100 min, cool it with the furnace, crush and sieve it to obtain carbide ceramic. Place the carbide ceramic into a mold, press it into shape, and vacuum sinter it at a heating rate of 10℃ / min. Sinter it at 1450℃ and hold it for 115 min to obtain high-entropy cemented carbide. The high-entropy cemented carbide has a density of 96.47%, a hardness of 13.61 GPa, and a fracture toughness of 7.2 MPa·m. 1 / 2 .

[0086] The experimental results from Examples 1-5 show that the high-entropy cemented carbide prepared by the technical solution provided by this invention has a density of over 99%, a hardness of over 15 GPa, and a fracture toughness of over 14 MPa·m. 1 / 2The high-entropy cemented carbide provided by this invention possesses high density, high hardness, and high fracture toughness. The experimental results of Examples 1-5 and Comparative Examples 1-5 show that, due to the simultaneous use of high-entropy carbide ceramics with non-equimolar ratios of different metal elements as the hard phase and the alloy as the binder phase, and the simultaneous use of a two-stage ball milling process and a cold-pressing-heat-treatment high-entropy carbide ceramic pre-preparation process in the preparation method, the high-entropy cemented carbide prepared by the technical solution provided by this invention exhibits significantly improved performance in terms of density, hardness, and fracture toughness.

[0087] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0088] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A high-entropy cemented carbide, characterized in that, The high-entropy cemented carbide is composed of 80-100% hard phase and 0-20% binder phase, with the total mass of the high-entropy cemented carbide being 100%; The hard phase is high-entropy carbide ceramic; the preparation raw materials of the high-entropy carbide ceramic include three or more than three of WC, TiC, Mo2C, NbC, TaC, VC, Cr2C3 and HfC, and the metal element ratio of different kinds of carbides is a non-equimolar ratio; The preparation raw materials of the high-entropy carbide ceramic include 0-70% WC, 5-60% TiC, 0-20% Mo2C, 0-30% NbC, 0-45% TaC, 0-30% VC, 0-20% Cr2C3 and 0-30% HfC, with the total mass of the high-entropy cemented carbide being 100%; The binder phase is an alloy; the preparation raw materials of the alloy include two or more than two of Co, Ni and Cu; The preparation raw materials of the alloy include 0-15% Co, 0-15% Ni and 0-10% Cu, with the total mass of the high-entropy cemented carbide being 100%; The preparation method of the high-entropy cemented carbide includes the following steps: Step S1: the preparation raw materials of the high-entropy carbide ceramic are weighed according to the mass ratio, the preparation raw materials, grinding medium and grinding balls are put into a ball mill tank, then inert gas is filled, one-time ball milling is carried out, the slurry is dried, the powder is crushed and sieved, and the high-entropy carbide powder is obtained; Step S2: the high-entropy carbide powder is cold-pressed into a shape, then is placed in a vacuum furnace for heat treatment, is crushed and sieved after furnace cooling, and the high-entropy carbide ceramic powder is obtained; Step S3: the high-entropy carbide ceramic powder, preparation raw materials of the alloy, grinding medium and grinding balls are put into a ball mill tank, then inert gas is filled, two-time ball milling is carried out, the slurry is dried, the powder is crushed and sieved, and the high-entropy cemented carbide powder is obtained; Step S4: the high-entropy cemented carbide powder is loaded into a mold for compression molding, then vacuum sintering is carried out by using a vacuum sintering technology, and the high-entropy cemented carbide is obtained.

2. The high-entropy cemented carbide according to claim 1, characterized in that The powder particle size of the WC, TiC, Mo2C, NbC, TaC, VC, Cr2C3 and HfC is 0.05-5 μm, and the powder purity is 98-100 wt%; The powder particle size of the Co, Ni and Cu is 0.5-5 μm, and the purity is 98-100 wt%.

3. The method of producing a high-entropy cemented carbide according to any one of claims 1 to 2, characterized in that, The preparation method of the high-entropy cemented carbide includes the following steps: Step S1: the preparation raw materials of the high-entropy carbide ceramic are weighed according to the mass ratio, the preparation raw materials, grinding medium and grinding balls are put into a ball mill tank, then inert gas is filled, one-time ball milling is carried out, the slurry is dried, the powder is crushed and sieved, and the high-entropy carbide powder is obtained; Step S2: the high-entropy carbide powder is cold-pressed into a shape, then is placed in a vacuum furnace for heat treatment, is crushed and sieved after furnace cooling, and the high-entropy carbide ceramic powder is obtained; Step S3: the high-entropy carbide ceramic powder, preparation raw materials of the alloy, grinding medium and grinding balls are put into a ball mill tank, then inert gas is filled, two-time ball milling is carried out, the slurry is dried, the powder is crushed and sieved, and the high-entropy cemented carbide powder is obtained; Step S4: the high-entropy cemented carbide powder is loaded into a mold for press forming, and then vacuum sintering is performed by using a vacuum sintering technology, so as to obtain the high-entropy cemented carbide.

4. The production method according to claim 3, characterized by, The raw material of the high-entropy carbide ceramic is three or more than three different kinds of carbides, and the metal element ratio of the different kinds of carbides is a non-equimolar ratio.

5. The preparation method according to claim 3, characterized in that, The grinding medium is one or more of anhydrous ethanol, acetone, ethane and gasoline.

6. The preparation method according to claim 3, characterized in that, The grinding ball is a tungsten carbide grinding ball, and the ball mill jar is a stainless steel ball mill jar.

7. The preparation method according to claim 3, characterized in that, In step S1, the first ball milling is performed under the conditions of a ball milling speed of 50-450 r / min, a ball milling time of 10-400 h, and a ball-to-powder ratio of 3-10:

1.

8. The preparation method according to claim 3, characterized in that, In step S2, the cold pressing is performed under the conditions of a cold pressing pressure of 30-100 MPa. The heat treatment is performed under the conditions of heat preservation at 1000-2000 ℃ for 20-180 min.

9. The preparation method according to claim 3, characterized in that, In step S3, the second ball milling is performed under the conditions of a ball milling speed of 50-150 r / min, a ball milling time of 5-30 h, and a ball-to-powder ratio of 2-5:

1.

10. The method of claim 3, wherein, In step S4, the vacuum sintering is performed under the conditions of heating at a rate of 3-20 ℃ / min to 1300-2000 ℃, and heat preservation for 30-200 min.