A tungsten cemented carbide, its preparation method and application

Abstract

This invention relates to the field of functional materials technology, and more particularly to a tungsten cemented carbide, its preparation method, and its applications. This invention further enhances the hardness of tungsten cemented carbide by using a specific amount of yttrium oxide and cerium oxide in combination. Furthermore, this invention utilizes graphene oxide to both increase the hardness of the tungsten cemented carbide and strengthen the integrity and processing performance of the components, ensuring effective bonding between yttrium oxide, cerium oxide, tungsten carbide, and titanium carbide. This invention introduces iron powder and cobalt powder, which act as a binder and promote the synergistic effect of yttrium oxide, cerium oxide, and graphene oxide, thereby forming a higher hardness tungsten cemented carbide while maintaining the overall performance of the tungsten-titanium-cobalt cemented carbide. The tungsten cemented carbide provided by this invention can meet the performance requirements of cutting or precision component applications, and can be processed into cutting tools or precision parts, with broad application prospects.

Description

Technical Field

[0001] This invention relates to the field of functional materials technology, and in particular to a tungsten cemented carbide, its preparation method, and its applications. Background Technology

[0002] Cemented carbide is an alloy material in which a hard compound of a refractory metal (such as tungsten carbide) serves as the hardening phase, bonded to a binder metal. Cemented carbide is widely used in cutting tools and precision components. With the continuous development of these fields, new requirements are naturally being placed on the performance of cemented carbide.

[0003] Cemented carbide possesses comprehensive properties such as high hardness, high strength, excellent wear resistance, and heat resistance, maintaining good cutting ability even at high temperatures. Based on its main components and applications, cemented carbide can be classified into tungsten-cobalt, tungsten-titanium-cobalt, and tungsten-titanium-tantalum (niobium) types. Among them, tungsten-titanium-cobalt cemented carbides exhibit high hardness, good wear resistance, and excellent red hardness. However, how to further improve the hardness of tungsten-titanium-cobalt cemented carbides without significantly reducing their overall performance remains a challenge in this field. Summary of the Invention

[0004] In view of this, the present invention provides a tungsten cemented carbide, its preparation method and application. The tungsten cemented carbide provided by the present invention has higher hardness and stable overall performance.

[0005] The present invention provides a tungsten cemented carbide comprising the following components in parts by weight: 95-100 parts of tungsten carbide, 45-75 parts of titanium carbide, 1-2 parts of yttrium oxide, 0.5-1 part of cerium oxide, 7-15 parts of graphene oxide, 3-8 parts of iron powder and 20-35 parts of cobalt powder.

[0006] Preferably, the tungsten carbide is tungsten carbide powder; the particle size of the tungsten carbide is 700~1500 nanometers.

[0007] Preferably, the titanium carbide is titanium carbide powder; the particle size of the titanium carbide is 700~1200 nanometers.

[0008] Preferably, the yttrium oxide is yttrium oxide powder; the particle size of the yttrium oxide is 300~600 nanometers; the cerium oxide is cerium oxide powder; the particle size of the cerium oxide is 500~1000 nanometers.

[0009] Preferably, the graphene oxide has a sheet diameter of 0.5 to 5 micrometers and has at least 3 layers.

[0010] Preferably, the iron powder has a particle size of 1-3 micrometers; the cobalt powder has a particle size of 1-3 micrometers.

[0011] The present invention also provides a method for preparing the tungsten cemented carbide described above, comprising the following steps:

[0012] Tungsten carbide, titanium carbide, yttrium oxide, cerium oxide, graphene oxide, iron powder, cobalt powder, and ethanol are mixed and then subjected to wet grinding, solvent removal, pressing, heat treatment, and sintering to obtain the tungsten cemented carbide.

[0013] Preferably, the heat treatment is carried out in a protective atmosphere; the temperature of the heat treatment is 700-800 degrees Celsius, and the holding time is 3-5 hours.

[0014] Preferably, the sintering is carried out in a protective atmosphere; the sintering includes sequentially performing a first heating, a first sintering, a second heating, a second sintering, a third heating, a third sintering, and a cooling; the heating rate of the first heating is 2~4℃ / min; the temperature of the first sintering is 650~800℃, and the holding time is 1~2 hours; the heating rate of the second heating is 3~5℃ / min; the temperature of the second sintering is 1200~1400℃, and the holding time is 1.5~2.5 hours; the heating rate of the third heating is 2~4℃ / min; the temperature of the third sintering is 1600~1650℃, and the holding time is 2~2.4 hours.

[0015] The present invention also provides the application of the tungsten cemented carbide described in the above-described scheme or the tungsten cemented carbide prepared by the above-described scheme in the field of cutting or precision parts.

[0016] This invention provides a tungsten cemented carbide. By using a specific amount of yttrium oxide and cerium oxide in combination, this invention further improves the hardness of the tungsten cemented carbide. Furthermore, this invention utilizes graphene oxide to both enhance the hardness of the tungsten cemented carbide and strengthen the integrity and processing performance of the components, ensuring effective bonding between yttrium oxide, cerium oxide, tungsten carbide, and titanium carbide. By introducing iron powder and cobalt powder, this invention acts as a binder and promotes the synergistic effect of yttrium oxide, cerium oxide, and graphene oxide, thereby forming a tungsten cemented carbide with higher hardness while maintaining the overall performance of the tungsten-titanium-cobalt cemented carbide.

[0017] This invention also provides a method for preparing the tungsten cemented carbide described above. This invention uses wet grinding to ensure effective dispersion of the components. Through heat treatment and segmented sintering, this invention allows the components to fully contact and form an alloy framework under high-temperature conditions, thereby improving the hardness of the tungsten cemented carbide while ensuring that wear resistance and other properties are not significantly affected.

[0018] This invention also provides applications of the tungsten cemented carbide described in the above-described scheme or the tungsten cemented carbide prepared by the above-described scheme in the fields of cutting or precision components. The tungsten cemented carbide provided by this invention can meet the performance requirements of the cutting or precision components fields, and can be processed into cutting tools or precision components, with broad application prospects. Detailed Implementation

[0019] The present invention provides a tungsten cemented carbide comprising the following components in parts by weight: 95-100 parts of tungsten carbide, 45-75 parts of titanium carbide, 1-2 parts of yttrium oxide, 0.5-1 part of cerium oxide, 7-15 parts of graphene oxide, 3-8 parts of iron powder and 20-35 parts of cobalt powder.

[0020] The tungsten cemented carbide provided by the present invention comprises 95 to 100 parts by weight, preferably 96 to 99 parts, more preferably 97 to 98 parts, and even more preferably 98 parts.

[0021] In this invention, the tungsten carbide is preferably tungsten carbide powder; the particle size of the tungsten carbide is preferably 700~1500 nanometers, more preferably 800~1300 nanometers, and even more preferably 900~1000 nanometers.

[0022] Based on the tungsten carbide, the tungsten cemented carbide provided by the present invention comprises 45-75 parts of titanium carbide, preferably 50-70 parts, more preferably 55-65 parts, and even more preferably 60-62.7 parts.

[0023] In this invention, the titanium carbide is preferably titanium carbide powder; the particle size of the titanium carbide is preferably 700~1200 nanometers, more preferably 800~1100 nanometers, and even more preferably 900~1000 nanometers.

[0024] Based on the tungsten carbide, the tungsten cemented carbide provided by the present invention includes 1 to 2 parts of yttrium oxide, preferably 1.2 to 1.7 parts, more preferably 1.4 to 1.7 parts, and even more preferably 1.6 parts.

[0025] In this invention, the yttrium oxide is preferably yttrium oxide powder; the particle size of the yttrium oxide is preferably 300-600 nanometers, more preferably 350-550 nanometers, and even more preferably 400-500 nanometers.

[0026] Based on the tungsten carbide, the tungsten cemented carbide provided by the present invention includes 0.5 to 1 part of cerium oxide, preferably 0.6 to 0.9 parts, more preferably 0.7 to 0.8 parts, and even more preferably 0.73 parts.

[0027] In this invention, the cerium oxide is preferably cerium oxide powder; the particle size of the cerium oxide is preferably 500~1000 nanometers, more preferably 550~900 nanometers, and even more preferably 600~850 nanometers.

[0028] Based on the tungsten carbide, the tungsten cemented carbide provided by the present invention includes 7 to 15 parts of graphene oxide, preferably 8 to 14 parts, more preferably 9 to 12 parts, and even more preferably 10 to 10.6 parts.

[0029] In this invention, the graphene oxide sheet diameter is preferably 0.5 to 5 micrometers, more preferably 0.5 to 1 micrometer, and the number of layers is preferably not less than 3.

[0030] Based on the tungsten carbide, the tungsten cemented carbide provided by the present invention comprises 3 to 8 parts of iron powder, preferably 4 to 7 parts, and more preferably 5 to 6 parts.

[0031] In this invention, the particle size of the iron powder is preferably 1 to 3 micrometers, more preferably 2 micrometers.

[0032] Based on the tungsten carbide, the tungsten cemented carbide provided by the present invention includes 20-35 parts of cobalt powder, preferably 24-33 parts, more preferably 27-31 parts, and even more preferably 29-30 parts.

[0033] In this invention, the particle size of the cobalt powder is preferably 1 to 3 micrometers, more preferably 2 micrometers.

[0034] The present invention also provides a method for preparing the tungsten cemented carbide described above, comprising the following steps:

[0035] Tungsten carbide, titanium carbide, yttrium oxide, cerium oxide, graphene oxide, iron powder, cobalt powder, and ethanol are mixed and then subjected to wet grinding, solvent removal, pressing, heat treatment, and sintering to obtain the tungsten cemented carbide.

[0036] In this invention, the ethanol is preferably anhydrous ethanol. This invention uses ethanol as a grinding medium in wet grinding.

[0037] In this invention, the wet grinding is preferably wet ball milling; the ball-to-material ratio of the wet ball milling is preferably 10-12:1, more preferably 11:1; the rotation speed of the wet grinding is preferably 80-100 rpm, more preferably 90 rpm; the grinding time is preferably 72-96 hours, more preferably 78-90 hours; and the liquid-to-solid ratio of the wet grinding is preferably 35-45:100, more preferably 40:100.

[0038] In this invention, the solvent removal is preferably drying; the drying temperature is preferably 25-40 degrees Celsius, and the drying time is preferably 2-4 hours, more preferably 3 hours.

[0039] In this invention, the pressing pressure is preferably 450~550MPa, more preferably 480~500MPa.

[0040] In this invention, the heat treatment is preferably carried out in a protective atmosphere; the protective atmosphere is preferably argon; the temperature of the heat treatment is preferably 700-800 degrees Celsius, more preferably 750 degrees Celsius, and the holding time is preferably 3-5 hours, more preferably 4 hours.

[0041] In this invention, the sintering is preferably carried out in a protective atmosphere; the protective atmosphere is preferably argon; the sintering preferably includes a first heating, a first sintering, a second heating, a second sintering, a third heating, a third sintering, and a cooling in sequence.

[0042] In this invention, the heating rate of the first heating is preferably 2~4℃ / min, more preferably 3℃ / min.

[0043] In this invention, the temperature of the first sintering is preferably 650-800 degrees Celsius, more preferably 700-750 degrees Celsius, and the holding time is preferably 1-2 hours, more preferably 1.5 hours.

[0044] In this invention, the heating rate of the second heating is preferably 3~5℃ / min, more preferably 4℃ / min.

[0045] In this invention, the second sintering temperature is preferably 1200~1400 degrees Celsius, more preferably 1250~1300 degrees Celsius, and the holding time is preferably 1.5~2.5 hours, more preferably 2 hours.

[0046] In this invention, the heating rate of the third heating is preferably 2~4℃ / min, more preferably 3℃ / min.

[0047] In this invention, the temperature of the third sintering is preferably 1600~1650 degrees Celsius, more preferably 1620~1630 degrees Celsius, and the holding time is preferably 2~2.4 hours, more preferably 2.2 hours.

[0048] In this invention, the cooling is preferably carried out with the furnace.

[0049] The present invention also provides the application of the tungsten cemented carbide described in the above-described scheme or the tungsten cemented carbide prepared by the above-described scheme in the field of cutting or precision parts.

[0050] The tungsten carbide provided by this invention can meet the performance requirements of the cutting field or the precision parts field, and can be processed into cutting tools or precision parts, with broad application prospects.

[0051] To further illustrate the present invention, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments thereof.

[0052] Example 1

[0053] In this embodiment, a tungsten cemented carbide was prepared, with the following specific components: 100 kg of tungsten carbide powder with a particle size of 700-1000 nm; 75 kg of titanium carbide powder with a particle size of 800-1100 nm; 2 kg of yttrium oxide powder with a particle size of 350-550 nm; 1 kg of cerium oxide powder with a particle size of 600-850 nm; 15 kg of graphene oxide with a sheet size of 0.5-1 μm and 3-4 layers; 8 kg of iron powder with a particle size of 1-3 μm; and 35 kg of cobalt powder with a particle size of 1-3 μm.

[0054] The specific steps for preparing tungsten cemented carbide in this embodiment are as follows: Tungsten carbide, titanium carbide, yttrium oxide, cerium oxide, graphene oxide, iron powder, and cobalt powder are added to anhydrous ethanol, and then wet-milled at a ball-to-material ratio of 12:1 and a liquid-to-solid ratio of 45:100 for 78 hours at 100 rpm. After milling, the mixture is dried at 40°C for 2 hours. Then, it is pressed into shape at 450 MPa and heat-treated at 800°C for 3 hours in an argon atmosphere. Next, it is sintered in an argon atmosphere: heating at 2°C / min and holding at 800°C for 1 hour; heating at 4°C / min and holding at 1400°C for 1.5 hours; heating at 3°C / min and holding at 1650°C for 2 hours; finally, it is cooled in the furnace to obtain tungsten cemented carbide.

[0055] Example 2

[0056] In this embodiment, a tungsten cemented carbide was prepared, with the following specific components: 95 kg of tungsten carbide powder with a particle size of 900-1500 nm; 45 kg of titanium carbide powder with a particle size of 700-1000 nm; 1.2 kg of yttrium oxide powder with a particle size of 300-600 nm; 0.9 kg of cerium oxide powder with a particle size of 500-850 nm; 10 kg of graphene oxide with a sheet size of 1-5 μm and 3-4 layers; 7 kg of iron powder with a particle size of 1-2 μm; and 20 kg of cobalt powder with a particle size of 1-2 μm.

[0057] The specific steps for preparing tungsten cemented carbide in this embodiment are as follows: tungsten carbide, titanium carbide, yttrium oxide, cerium oxide, graphene oxide, iron powder, and cobalt powder are added to anhydrous ethanol, and then wet-milled at a ball-to-material ratio of 10:1 and a liquid-to-solid ratio of 35:100 for 90 hours at 80 rpm. After milling, the mixture is dried at 25°C for 4 hours. Then, it is pressed into shape at 550 MPa and heat-treated at 800°C for 3 hours in an argon atmosphere. Next, it is sintered in an argon atmosphere: heating at 2°C / min and holding at 650°C for 2 hours; heating at 4°C / min and holding at 1400°C for 1.5 hours; heating at 3°C / min and holding at 1630°C for 2.2 hours; finally, it is cooled in the furnace to obtain tungsten cemented carbide.

[0058] Example 3

[0059] In this embodiment, a tungsten cemented carbide was prepared, with the following specific components: 97 kg of tungsten carbide powder with a particle size of 800-1300 nm; 55 kg of titanium carbide powder with a particle size of 900-1200 nm; 1 kg of yttrium oxide powder with a particle size of 400-550 nm; 1 kg of cerium oxide powder with a particle size of 550-900 nm; 9 kg of graphene oxide with a sheet size of 0.5-1 μm and 4-5 layers; 5 kg of iron powder with a particle size of 1-2 μm; and 27 kg of cobalt powder with a particle size of 1-2 μm.

[0060] The specific steps for preparing tungsten cemented carbide in this embodiment are as follows: Tungsten carbide, titanium carbide, yttrium oxide, cerium oxide, graphene oxide, iron powder, and cobalt powder are added to anhydrous ethanol, and then wet-milled at a ball-to-material ratio of 11:1 and a liquid-to-solid ratio of 40:100 for 78 hours at a speed of 90 rpm. After milling, the mixture is dried at 30°C for 3 hours. Then, it is pressed into shape at 480 MPa and heat-treated at 750°C for 4 hours in an argon atmosphere. Next, it is sintered in an argon atmosphere: heating at 3°C / min and holding at 760°C for 1.5 hours; heating at 5°C / min and holding at 1250°C for 2 hours; heating at 3°C / min and holding at 1620°C for 2.2 hours; finally, it is cooled in the furnace to obtain tungsten cemented carbide.

[0061] Example 4

[0062] In this embodiment, a tungsten cemented carbide was prepared with the following specific components: 99 kg of tungsten carbide powder with a particle size of 800-1300 nm; 65 kg of titanium carbide powder with a particle size of 700-1000 nm; 1.4 kg of yttrium oxide powder with a particle size of 350-550 nm; 0.8 kg of cerium oxide powder with a particle size of 550-900 nm; 12 kg of graphene oxide with a sheet size of 2-5 μm and 3-4 layers; 8 kg of iron powder with a particle size of 1-2 μm; and 29 kg of cobalt powder with a particle size of 1-3 μm.

[0063] The specific steps for preparing tungsten cemented carbide in this embodiment are as follows: Tungsten carbide, titanium carbide, yttrium oxide, cerium oxide, graphene oxide, iron powder, and cobalt powder are added to anhydrous ethanol, and then wet-milled at a ball-to-material ratio of 11:1 and a liquid-to-solid ratio of 40:100 for 90 hours at a speed of 90 rpm. After milling, the mixture is dried at 30°C for 3 hours. Then, it is pressed into shape at 500 MPa and heat-treated at 750°C for 5 hours in an argon atmosphere. Next, it is sintered in an argon atmosphere: heating at 4°C / min and holding at 750°C for 1.5 hours; heating at 5°C / min and holding at 1300°C for 2.5 hours; heating at 3°C / min and holding at 1630°C for 2.4 hours; finally, it is cooled in the furnace to obtain tungsten cemented carbide.

[0064] Example 5

[0065] In this embodiment, a tungsten cemented carbide was prepared, with the following specific components: 98 kg of tungsten carbide powder with a particle size of 1000-1500 nm; 70 kg of titanium carbide powder with a particle size of 900-1200 nm; 1.7 kg of yttrium oxide powder with a particle size of 300-500 nm; 0.9 kg of cerium oxide powder with a particle size of 550-900 nm; 14 kg of graphene oxide with a sheet size of 0.5-5 μm and 3-4 layers; 6 kg of iron powder with a particle size of 1-2 μm; and 31 kg of cobalt powder with a particle size of 1-2 μm.

[0066] The specific steps for preparing tungsten cemented carbide in this embodiment are as follows: Tungsten carbide, titanium carbide, yttrium oxide, cerium oxide, graphene oxide, iron powder, and cobalt powder are added to anhydrous ethanol, and then wet-milled at a ball-to-material ratio of 11:1 and a liquid-to-solid ratio of 40:100 for 80 hours at a speed of 90 rpm. After milling, the mixture is dried at 35°C for 3 hours. Then, it is pressed into shape at 480 MPa and heat-treated at 720°C for 4 hours in an argon atmosphere. Next, it is sintered in an argon atmosphere: heating at 3°C / min and holding at 750°C for 1.5 hours; heating at 5°C / min and holding at 1300°C for 2 hours; heating at 3°C / min and holding at 1620°C for 2.2 hours; finally, it is cooled in the furnace to obtain tungsten cemented carbide.

[0067] Example 6

[0068] In this embodiment, a tungsten cemented carbide was prepared with the following specific components: 96 kg of tungsten carbide powder with a particle size of 700-1100 nm; 62.7 kg of titanium carbide powder with a particle size of 700-1000 nm; 1.6 kg of yttrium oxide powder with a particle size of 400-600 nm; 0.73 kg of cerium oxide powder with a particle size of 500-750 nm; 10.6 kg of graphene oxide with a sheet size of 1-3 μm and 3-4 layers; 4 kg of iron powder with a particle size of 1-2 μm; and 33 kg of cobalt powder with a particle size of 1-2 μm.

[0069] The specific steps for preparing tungsten cemented carbide in this embodiment are as follows: Tungsten carbide, titanium carbide, yttrium oxide, cerium oxide, graphene oxide, iron powder, and cobalt powder are added to anhydrous ethanol, and then wet-milled at a ball-to-material ratio of 11:1 and a liquid-to-solid ratio of 40:100 for 84 hours at a speed of 90 rpm. After milling, the mixture is dried at 30°C for 3 hours. Then, it is pressed into shape at 500 MPa and heat-treated at 750°C for 4 hours in an argon atmosphere. Next, it is sintered in an argon atmosphere: heating at 3°C / min and holding at 750°C for 1.5 hours; heating at 4°C / min and holding at 1300°C for 2 hours; heating at 2°C / min and holding at 1620°C for 2.2 hours; finally, it is cooled in the furnace to obtain tungsten cemented carbide.

[0070] Example 7

[0071] In this embodiment, a tungsten cemented carbide was prepared with the following specific components: 97 kg of tungsten carbide powder with a particle size of 800-1300 nm; 50 kg of titanium carbide powder with a particle size of 800-1100 nm; 1.7 kg of yttrium oxide powder with a particle size of 300-450 nm; 0.7 kg of cerium oxide powder with a particle size of 550-900 nm; 7 kg of graphene oxide with a sheet size of 1-3 μm and 3-4 layers; 3 kg of iron powder with a particle size of 1-2 μm; and 24 kg of cobalt powder with a particle size of 1-3 μm.

[0072] The specific steps for preparing tungsten cemented carbide in this embodiment are as follows: Tungsten carbide, titanium carbide, yttrium oxide, cerium oxide, graphene oxide, iron powder, and cobalt powder are added to anhydrous ethanol, and then wet-milled at a ball-to-material ratio of 11:1 and a liquid-to-solid ratio of 40:100 for 84 hours at a speed of 90 rpm. After milling, the mixture is dried at 40°C for 3 hours. Then, it is pressed into shape at 500 MPa and heat-treated at 800°C for 4 hours in an argon atmosphere. Next, it is sintered in an argon atmosphere: heating at 3°C / min and holding at 800°C for 1.5 hours; heating at 5°C / min and holding at 1250°C for 2 hours; heating at 3°C / min and holding at 1630°C for 2.3 hours; finally, it is cooled in the furnace to obtain tungsten cemented carbide.

[0073] Example 8

[0074] In this embodiment, a tungsten cemented carbide was prepared with the following specific components: 98 kg of tungsten carbide powder with a particle size of 800-1300 nm; 60 kg of titanium carbide powder with a particle size of 800-1100 nm; 1.7 kg of yttrium oxide powder with a particle size of 350-550 nm; 0.6 kg of cerium oxide powder with a particle size of 550-900 nm; 8 kg of graphene oxide with a sheet size of 1-3 μm and 3-4 layers; 4 kg of iron powder with a particle size of 1-3 μm; and 30 kg of cobalt powder with a particle size of 1-3 μm.

[0075] The specific steps for preparing tungsten cemented carbide in this embodiment are as follows: tungsten carbide, titanium carbide, yttrium oxide, cerium oxide, graphene oxide, iron powder, and cobalt powder are added to anhydrous ethanol, and then wet-milled at a ball-to-material ratio of 11:1 and a liquid-to-solid ratio of 40:100 for 90 hours at a speed of 90 rpm. After milling, the mixture is dried at 40°C for 3 hours. Then, it is pressed into shape at 500 MPa and heat-treated at 750°C for 4 hours in an argon atmosphere. Next, it is sintered in an argon atmosphere: heating at 3°C / min and holding at 750°C for 1.5 hours; heating at 4°C / min and holding at 1300°C for 2 hours; heating at 2°C / min and holding at 1630°C for 2.2 hours; finally, it is cooled in the furnace to obtain tungsten cemented carbide.

[0076] Example 9

[0077] In this embodiment, a tungsten cemented carbide was prepared with the following specific components: 98 kg of tungsten carbide powder with a particle size of 800-1300 nm; 55 kg of titanium carbide powder with a particle size of 800-1100 nm; 1.6 kg of yttrium oxide powder with a particle size of 350-550 nm; 0.5 kg of cerium oxide powder with a particle size of 550-900 nm; 12 kg of graphene oxide with a sheet size of 1-3 μm and 3-4 layers; 7 kg of iron powder with a particle size of 1-2 μm; and 30 kg of cobalt powder with a particle size of 1-3 μm.

[0078] The specific steps for preparing tungsten cemented carbide in this embodiment are as follows: tungsten carbide, titanium carbide, yttrium oxide, cerium oxide, graphene oxide, iron powder, and cobalt powder are added to anhydrous ethanol, and then wet-milled at a ball-to-material ratio of 11:1 and a liquid-to-solid ratio of 40:100 for 90 hours at a speed of 90 rpm. After milling, the mixture is dried at 40°C for 4 hours. Then, it is pressed into shape at 500 MPa and heat-treated at 750°C for 4 hours in an argon atmosphere. Next, it is sintered in an argon atmosphere: heating at 4°C / min and holding at 750°C for 1.5 hours; heating at 5°C / min and holding at 1300°C for 2 hours; heating at 3°C / min and holding at 1630°C for 2.2 hours; finally, it is cooled in the furnace to obtain tungsten cemented carbide.

[0079] Example 10

[0080] In this embodiment, a tungsten cemented carbide was prepared with the following specific components: 98 kg of tungsten carbide powder with a particle size of 800-1200 nm; 65 kg of titanium carbide powder with a particle size of 800-1000 nm; 1.6 kg of yttrium oxide powder with a particle size of 350-550 nm; 0.5 kg of cerium oxide powder with a particle size of 550-900 nm; 12 kg of graphene oxide with a sheet size of 1-3 μm and 3-4 layers; 7 kg of iron powder with a particle size of 1-2 μm; and 30 kg of cobalt powder with a particle size of 1-3 μm.

[0081] The specific steps for preparing tungsten cemented carbide in this embodiment are as follows: tungsten carbide, titanium carbide, yttrium oxide, cerium oxide, graphene oxide, iron powder, and cobalt powder are added to anhydrous ethanol, and then wet-milled at a ball-to-material ratio of 11:1 and a liquid-to-solid ratio of 40:100 for 84 hours at a speed of 90 rpm. After milling, the mixture is dried at 40°C for 4 hours. Then, it is pressed into shape at 500 MPa and heat-treated at 750°C for 4 hours in an argon atmosphere. Next, it is sintered in an argon atmosphere: heating at 4°C / min and holding at 750°C for 1.5 hours; heating at 5°C / min and holding at 1300°C for 2 hours; heating at 3°C / min and holding at 1600°C for 2.2 hours; finally, it is cooled in the furnace to obtain tungsten cemented carbide.

[0082] Comparative Example 1

[0083] The preparation method of this comparative example is the same as that of Example 9, except that no graphene oxide was added.

[0084] Comparative Example 2

[0085] The preparation method of this comparative example is the same as that of Example 9, except that yttrium oxide is replaced with an equal mass of cerium oxide.

[0086] Comparative Example 3

[0087] The preparation method of this comparative example is the same as that of Example 9, except that cerium oxide is replaced with an equal mass of yttrium oxide.

[0088] Comparative Example 4

[0089] The preparation method of this comparative example is the same as that of Example 9, except that the sintering is carried out in an argon atmosphere: the temperature is increased by 4°C / min and held at 750°C for 1.5 hours; the temperature is increased by 3°C / min and held at 1630°C for 2.2 hours.

[0090] Comparative Example 5

[0091] The preparation method of this comparative example is the same as that of Example 9, except that heat treatment is omitted.

[0092] Comparative Example 6

[0093] The preparation method of this comparative example is the same as that of Example 9, except that the iron powder is replaced with an equal mass of cobalt powder.

[0094] Test Example 1

[0095] The tungsten cemented carbides prepared in Examples 1-10 and Comparative Examples 1-6 were subjected to performance testing. The results are shown in Table 1. The unit of hardness is kg / mm. 2 .

[0096] Table 1. Properties of tungsten carbides in Examples 1-10 and Comparative Examples 1-6

[0097]

[0098] As shown in Table 1, the tungsten cemented carbide provided by this invention is significantly superior in hardness to comparative examples 1-6, demonstrating a new breakthrough in the hardness of tungsten cemented carbides. Furthermore, the tungsten cemented carbide provided by this invention does not exhibit significant degradation in key properties such as fracture toughness, bending strength, and heat resistance; these properties remain essentially stable. Therefore, the tungsten cemented carbide provided by this invention achieves improved hardness without compromising other key properties, and its overall performance is significantly superior to existing tungsten-titanium-cobalt cemented carbides, exhibiting enormous application potential. For example, it can be used in cutting tools or precision components to extend their service life, resulting in significant social and economic benefits.

[0099] According to the above embodiments and comparative examples, the reason why the tungsten cemented carbide of the present invention achieves the above-mentioned effects is that: yttrium oxide and cerium oxide form a composite rare earth element, which has a synergistic effect. Both are indispensable and jointly contribute to the hardness of the tungsten cemented carbide. Furthermore, graphene oxide, as a component that synergizes with the aforementioned composite rare earth element, further enhances the hardness-improving effect of the composite rare earth element and effectively integrates the compatibility between the components, resulting in the tungsten cemented carbide exhibiting excellent properties such as fracture toughness and bending strength that remain essentially unchanged. The present invention further improves the hardness and other properties of the tungsten cemented carbide through specific heat treatment and staged sintering processes. In summary, the present invention, by addressing both the composition and preparation method, achieves a synergistic effect, thus preparing a high-performance, high-hardness tungsten cemented carbide.

[0100] The embodiments of the present invention have been described above; however, these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. All other embodiments obtained by those skilled in the art based on the above embodiments of the present invention without inventive effort are within the protection scope of the present invention.

Claims

1. A tungsten cemented carbide, characterized in that, It is prepared from the following raw materials in parts by weight: tungsten carbide 95-100 parts, titanium carbide 45-75 parts, yttrium oxide 1-2 parts, cerium oxide 0.5-1 parts, graphene oxide 7-15 parts, iron powder 3-8 parts and cobalt powder 20-35 parts.

2. The tungsten cemented carbide according to claim 1, characterized in that, The tungsten carbide is tungsten carbide powder; The tungsten carbide has a particle size of 700~1500 nanometers.

3. The tungsten cemented carbide according to claim 1, characterized in that, The titanium carbide is titanium carbide powder; The titanium carbide has a particle size of 700~1200 nanometers.

4. The tungsten cemented carbide according to claim 1, characterized in that, The yttrium oxide is yttrium oxide powder; The yttrium oxide has a particle size of 300-600 nanometers; The cerium oxide is cerium oxide powder; The cerium oxide has a particle size of 500~1000 nanometers.

5. The tungsten cemented carbide according to claim 1, characterized in that, The graphene oxide has a sheet diameter of 0.5 to 5 micrometers and has no fewer than 3 layers.

6. The tungsten cemented carbide according to claim 1, characterized in that, The iron powder has a particle size of 1-3 micrometers; The cobalt powder has a particle size of 1-3 micrometers.

7. The method for preparing the tungsten cemented carbide according to any one of claims 1 to 6, characterized in that, Includes the following steps: Tungsten carbide, titanium carbide, yttrium oxide, cerium oxide, graphene oxide, iron powder, cobalt powder, and ethanol are mixed and then subjected to wet grinding, solvent removal, pressing, heat treatment, and sintering to obtain the tungsten cemented carbide. The heat treatment temperature is 700-800 degrees Celsius, and the holding time is 3-5 hours.

8. The preparation method according to claim 7, characterized in that, The heat treatment is carried out in a protective atmosphere.

9. The preparation method according to claim 7, characterized in that, The sintering is carried out in a protective atmosphere; The sintering process includes a first heating, a first sintering, a second heating, a second sintering, a third heating, a third sintering, and a cooling process performed sequentially. The heating rate of the first heating is 2~4℃ / min; The first sintering temperature is 650~800 degrees Celsius, and the holding time is 1~2 hours; The second heating rate is 3~5℃ / min; The second sintering temperature is 1200~1400 degrees Celsius, and the holding time is 1.5~2.5 hours; The heating rate for the third heating step is 2~4℃ / min; The third sintering temperature is 1600~1650 degrees Celsius, and the holding time is 2~2.4 hours.

10. The application of the tungsten cemented carbide according to any one of claims 1 to 6 or the tungsten cemented carbide obtained by the preparation method according to any one of claims 7 to 9 in the field of cutting or precision parts.

Images